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AKT
AKT AKT(4)
The Akt/PI3K pathway is a key regulator of survival during cellular stress, by inhibiting apoptosis, through phosphorylation of transcription factors, including BAD, MDM2, and FOXO.(1-4) PI3K represents a family of lipid kinases which are key regulators cell survival, growth, and differentiation.(5) There are four distinct PI3K subfamilies, classes I, II, III, and IV.(6) Akt1 is a serine/threonine-specific protein kinase that plays key roles in glucose metabolism, apoptosis, cell proliferation, transcription, and cell migration.(3) Akt1 is also able to induce protein synthesis pathways.
PI3K transduces signals received from activated RTK, GPCR, or RAS. PTEN can inactivate the PI3K pathway.(7) Akt/PKB can inactivate pro-apoptotic factors such as Bad, Procaspase-9, and the Forkhead family of transcription factors that induce the expression of other pro-apoptotic factors (e.g. FasL).(4, 8, 9) Class I PI3K and TORC2 activate AKT. The Ras/Raf/MEK/ERK and PI3K/PTEN/Akt/mTOR cascades are often activated by genetic alterations in upstream signaling molecules.(10) Akt2 is an important signaling molecule in the insulin signaling pathway, and is required to induce glucose transport.(3)
Tumor cells that have constitutively active Akt may depend on Akt for survival.(3) The RAS/RAF/MEK/ERK pathway is activated in most cancer cells to promote cell survival, sometimes converging on shared targets with PI3K/mTOR. In many cases, the PI3K and RAS pathways are downstream of activated RTKs (e.g. EGFR) or non-RTKs such as BCR-ABL.(1) Mechanisms of PI3K activation in cancer include upregulated receptors upstream of PI3K, amplification or gain-of-function mutations, and inactivation of PTEN.(11)
Although inhibitors of class I PI3Ks prevent full activation of Akt/PKB, Akt can also be activated by inhibitor of nuclear factor B kinase; PI3K inhibition may not fully silence Akt/PKB.(12) Unfortunately, direct targeting of Akt could increase PI3K-dependent activation through increased mTORC1 activity, via negative feedback inhibiting insulin-stimulated PI3K activation.(13) Because of this negative feedback, when mTORC1 is active, the Akt/PI3K pathway is suppressed, whereas if mTORC1 is inhibited (e.g., with rapamycin), Akt/PI3K signaling can actually be enhanced promoting tumor survival.(6)

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References

1. Yea SS, Fruman DA. Achieving cancer cell death with PI3K/mTOR?targeted therapies. Annals of the New York Academy of Sciences. 2013;1280(1):15-8.

2. Manning BD, Cantley LC. AKT/PKB signaling: navigating downstream. Cell. 2007;129(7):1261-74.

3. Ward EM, Thun MJ, Hannan LM, Jemal A. Interpreting cancer trends. Annals of the New York Academy of Sciences. 2006;1076(1):29-53.

4. Porta C, Paglino C, Mosca A. Targeting PI3K/Akt/mTOR signaling in cancer. Frontiers in oncology. 2014;4.

5. Khan KH, Yap TA, Yan L, Cunningham D. Targeting the PI3K-AKT-mTOR signaling network in cancer. Chinese journal of cancer. 2013;32(5):253.

6. Foster JG, Blunt MD, Carter E, Ward SG. Inhibition of PI3K signaling spurs new therapeutic opportunities in inflammatory/autoimmune diseases and hematological malignancies. Pharmacological reviews. 2012;64(4):1027-54.

7. Brana I, Siu LL. Clinical development of phosphatidylinositol 3-kinase inhibitors for cancer treatment. BMC medicine. 2012;10(1):161.

8. Pawson T, Nash P. Protein-protein interactions define specificity in signal transduction. Genes & Development. 2000;14(9):1027-47.

9. Testa JR, Bellacosa A. AKT plays a central role in tumorigenesis. Proceedings of the National Academy of Sciences. 2001;98(20):10983-5.

10. McCubrey JA, Steelman LS, Chappell WH, Abrams SL, Franklin RA, Montalto G, et al. Ras/Raf/MEK/ERK and PI3K/PTEN/Akt/mTOR cascade inhibitors: how mutations can result in therapy resistance and how to overcome resistance. Oncotarget. 2012;3(10):1068.

11. Massacesi C, Tomaso E, Fretault N, Hirawat S. Challenges in the clinical development of PI3K inhibitors. Annals of the New York Academy of Sciences. 2013;1280(1):19-23.

12. Guo J-P, Coppola D, Cheng JQ. IKBKE protein activates Akt independent of phosphatidylinositol 3-kinase/PDK1/mTORC2 and the pleckstrin homology domain to sustain malignant transformation. Journal of Biological Chemistry. 2011;286(43):37389-98.

13. Guertin DA, Sabatini DM. The pharmacology of mTOR inhibition. Science signaling. 2009;2(67):pe24.



News


4:06 PM|Current Cancer Drug Targets (Volume 16 - Issue 8)|Labels: AKT, MM
Background: Multiple myeloma (MM), a clonal B cell malignancy characterized by the proliferation of plasma cells within the bone marrow, is still an incurable disease, and therefore, finding new therapeutic targets is urgently required. Although microRNA-137 (miR-137), which is involved in a variety of cellular processes, has been reported to be under-expressed in many types of solid tumors, its role in MM is less known.

Methods: In this study, the target gene and the potential effect of miR-137 in MM were investigated.

Results: The results showed significantly down regulated expression of miR-137 in MM cell lines and in the CD138+ bone marrow mononuclear cells of MM patients. A dual luciferase reporter gene analysis revealed that MITF is a direct target of miR-137. The overexpression of miR-137 or transfection of MITF-shRNA had no significant effect on the expression of serine/ threonine protein kinase (AKT), but the expression of MITF, c-MET, p-AKT, and its phosphorylated substrate protein decreased significantly, which was accompanied by an increase in p53 expression. In addition, the overexpression of miR-137 or MITF-shRNA significantly improved the 36-hour inhibition rate and apoptosis rate in multiple myeloma cells treated with dexamethasone. The overexpression of MITF could counteract the biological effect of miR-137 in multiple myeloma cells.

Conclusion: We conclude that MITF is a direct target of miR-137. The miR-137 can improve the dexamethasone sensitivity in multiple myeloma cells by reducing the c-MET expression and further decreasing the AKT phosphorylation via targeting MITF.

4:06 PM|Current Medicinal Chemistry-Anti-Cancer Agents (Volume 5 - Issue 6)|Labels: AKT
The phosphatidylinositol 3-kinase (PI3K)/Akt (protein kinase B, PKB) signaling pathway plays a critical role in cell growth and survival. Dysregulation of this pathway has been found in a variety of cancer cells. Recently, constitutively active PI3K/Akt signaling has been firmly established as a major determinant for cell growth and survival in an array of cancers. Blocking the constitutively active PI3K/AKT signaling pathway provides a new strategy for targeted cancer therapy. Thus, inhibitors of this signaling pathway would be potential anticancer agents, particularly for cancer cells whose survival and growth are dominated by constitutively active PI3K/Akt signaling. This review describes the current understanding of small molecule drugs targeting this pathway both in vitro and in vivo. Inhibitors and functions of the upstream and downstream molecular targets of the PI3K/Akt pathway are discussed in the context of using the inhibitors to block this pathway for targeted cancer therapy. Special emphasis is placed on the following targets: receptor tyrosine kinases, PI3K, Akt, and the mammalian target of rapamycin. While the molecular therapeutic strategy holds great promise for the treatment of a variety of cancers, few small molecule inhibitors with potential high therapeutic indexes are available. Thus, new inhibitors with high selectivity, bioavailability, and potency are greatly needed. Novel approaches toward the development of PI3K/Akt pathway inhibitors as anticancer therapeutics are discussed in detail, with emphasis on chemical genetics-based and structure-based drug design.
6:46 AM|WU, Y.-L., ZHANG, L., TRANDAFIR, L., DONG, T., DUVAL, V., HAZELL, K., XU, B.|Anticancer Research current issue|Labels: AKT

Background/Aim: The phosphatidylinositol-3-kinase (PI3K) signaling pathway is frequently activated in cancer. Buparlisib (BKM120), an oral pan-PI3K inhibitor, inhibits proliferation of human cancer in preclinical models. Studies of buparlisib in Western and Japanese adults with advanced solid tumors established a recommended dose of 100 mg/day and showed an acceptable safety profile and evidence of efficacy. This phase I dose-escalation/expansion study aimed to establish the maximum tolerated dose (MTD) of single-agent, once daily oral buparlisib in Chinese patients with advanced solid tumors. Materials and Methods: Patients (n=32; primary tumor site: lung (n=15), breast (n=10) or head and neck (n=7); ≥2 prior lines of antineoplastic therapy (n=26)) received 80 mg (n=15) or 100 mg (n=17) daily buparlisib. Results: Five patients experienced dose-limiting toxicities: grade (G)3 depression (n=1), G2 hyperglycemia (n=3) and G3 hyperglycemia (n=1). Most frequent buparlisib-related adverse events were hyperglycemia (n=18; 56%), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) increase (n=9; 28%), as well as anxiety (n=6; 19%); most common buparlisib-related G3/4 adverse events: hyperglycemia (n=3; 9%), ALT and AST increase (n=2; 6%), as well as gamma-glutamyltransferase increase (n=2; 6%). Best response was stable disease (SD) in 10 patients (31%). Conclusion: The MTD of buparlisib was declared as 100 mg/day. Safety, efficacy and pharmacokinetic data from this study were similar to those previously reported in Western and Japanese populations.

6:46 AM|CHOI, A.-R., KIM, J.-H., WOO, Y. H., CHEON, J. H., KIM, H. S., YOON, S.|Anticancer Research current issue|Labels: AKT

Clinical trials are in progress on AZD5363, an inhibitor of protein kinase B (AKT), to assess its effects on the phosphoinositide 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) pathway. Cells treated with AKT inhibitors have been reported to activate alternative pathways in order to escape growth inhibition. AZD5363-sensitized Hs578T breast cancer cells displayed reduced levels of phosphorylated glycogen synthase kinase 3 beta (pGSK3β). Interestingly, in AZD5363-treated cells, the level of phosphorylated (activated) AKT (pAKT) increased. Since pAKT positively correlates with cancer growth and survival, we aimed to identify conditions that could reduce AZD5363-induction of pAKT. We examined whether AZD5363 induction of pAKT could be reduced by co-treatment with inhibitors of the PI3K/AKT/mTOR pathway (LY294002, MK-2206, wortmannin, perifosine, rapamycin, everolimus, and temsirolimus). We observed that co-treatment of LY294002 or MK-2206 with AZD5363 reduced the level of pAKT. Since MK-2206 is clinically used, we propose that co-treatment using MK-2206 with AZD5363 would prove beneficial in blocking the AZD5363-induced pAKT signaling pathway. Our findings contribute to the development of AZD5363-based sensitization therapies for patients with cancer.

6:46 AM|LIM, H. J., WANG, X., CROWE, P., GOLDSTEIN, D., YANG, J.-L.|Anticancer Research current issue|Labels: AKT, sarcoma

Background/Aim: Sarcoma carries a poor prognosis prompting the need for targeted therapies aimed at deregulated signaling pathways. These include the PI3K/Akt/mTOR pathway commonly up-regulated in malignancies attributed to loss of PTEN expression. However, PTEN status and activation state of PI3K/Akt/mTOR pathway have not been comprehensively studied in sarcoma. The aims of this study were to characterise PTEN and Akt expression in a panel of sarcoma cell lines and then to examine mTOR inhibition using ridaforolimus. Materials and Methods: PTEN genomic expression was analyzed using Sanger sequencing. PTEN, total Akt (tAkt) and phosphorylated Akt (pAkt) expression were quantified with western blot analysis. Antiproliferative effects of treatment regimens were designed using Chou & Talalay's isobologram and determined with crystal violet assay. Results: Four cell lines had wild-type PTEN (exons 2 to 8), with normal protein expression. The GCT cell line had a missense mutation in exon 6 (C>T), associated with loss of PTEN protein expression. Increased pAkt expression was found in all cell lines following epidermal growth factor (EGF) stimulation, indicating that wild-type PTEN expression in four cell lines did not inhibit constitutive activation of PI3K/Akt/mTOR pathway. Nonetheless, all cell lines demonstrated sensitivity to ridaforolimus within a clinically relevant dose-range (half-maximal inhibitory concentration (IC50)=0.7-10 nM). Conclusion: PTEN mutation is rare in sarcoma cell lines and constitutive activation of PI3K/Akt/mTOR is independent of PTEN status.

Wednesday, October 26, 2016 1:52 PM|Deng, C., Lipstein, M. R., Scotto, L., Jirau Serrano, X. O., Mangone, M. A., Li, S., Vendome, J., Hao, Y., Xu, X., Deng, S.-X., Realubit, R. B., Tatonetti, N. P., Karan, C., Lentzsch, S., Fruman, D. A., Honig, B., Landry, D. W., O'Connor, O. A.|BLOOD First Edition Papers|Labels: AKT

Phosphoinositide 3-kinase (PI3K) and the proteasome pathway are both involved in activating the mechanistic target of rapamycin (mTOR). Because mTOR signaling is required for initiation of mRNA translation, we hypothesized that co-targeting the PI3K and proteasome pathways might synergistically inhibit translation of c-Myc. We found that a novel PI3K delta isoform inhibitor TGR-1202, but not the approved PI3K inhibitor idelalisib, was highly synergistic with the proteasome inhibitor carfilzomib in lymphoma, leukemia, and myeloma cell lines and primary lymphoma and leukemia cells. TGR-1202 and carfilzomib (TC) synergistically inhibited phosphorylation of the eukaryotic translation initiation factor 4E (eIF4E)-binding protein 1 (4E-BP1), leading to suppression of c-Myc translation and silencing of c-Myc dependent transcription. The synergistic cytotoxicity of TC was rescued by overexpression of eIF4E or c-Myc. TGR-1202, but not other PI3K inhibitors, inhibited casein kinase-1 (CK1) epsilon. Targeting CK1 using a selective chemical inhibitor or shRNA complements the effects of idelalisib, as a single agent or in combination with carfilzomib, in repressing phosphorylation of 4E-BP1 and the protein level of c-Myc. These results suggest that TGR-1202 is a dual PI3K/CK1 inhibitor, which may in part explain the clinical activity of TGR-1202 in aggressive lymphoma not found with idelalisib. Targeting CK1 should become an integral part of therapeutic strategies targeting translation of oncogenes such as c-Myc.

Tuesday, October 25, 2016 11:51 PM|buyresearchchemicalss|EGFR Tyrosine Kinase Inhibitors Activate Autophagy|Labels: AKT, ALL

Background T-cell Acute Lymphoblastic Leukemia (ALL) represents about 10-15?% of pediatric ALL instances. of disease-free success (DFS) in comparison to T-ALL adverse for EZH2 (23?% vs 100?%) (p?=?0.01). The EZH2 inhibitor DZNep found in mixture with Daunoblastine was synergistic in inducing development inhibition and raising the apoptosis in T-ALL Jurkat cells at 48 and 72?h paralleled by EZH2 decreased manifestation. Moreover the mixture decreased the experience of Erk-1/2 proliferation enzymes without results on JIB-04 Akt success pathway. Conclusions The evaluation of EZH2 manifestation in pediatric T-ALL can be handy in forecast the clinical result of the individuals and EZH2 could be a useful focus on to boost the effectiveness of regular chemotherapy with this subset of individuals with poor prognosis. and [11-16]. The systems and ramifications of DZNep have already been studied in a number of solid tumors and severe myeloid leukemia much less is well known about the of this substance for Rabbit Polyclonal to BCLAF1. T-cell ALL [8]. Daunoblastine a non-selective course I anthracycline functions by binding to DNA-associated enzymes and intercalates the bottom pairs from the DNA’s dual helix. Although daunoblastine continues to be utilized as an anti-leukemic agent for many years its success can be often reliant on mixture with other medicines [17]. In today’s research we examined the manifestation degrees of EZH2 SUZ12 and EED in samples of T cells ALL. Moreover we examined the consequences of DZNep only or in conjunction with Daunoblastine on founded T cell Jurkat JIB-04 range. Strategies Lymphoblastic leukemia cells were collected from pediatric patients diagnosed and treated for T-cell Acute Lymphoblastic Leukemia (T-ALL) at the Pediatric Oncology Unit of Second University of Naples and isolated from bone marrow at diagnosis with density gradient centrifugation Histopaque-1077 (1.077?g/ml; Sigma-Aldrich). The study was approved by the Ethical Committee of the Azienda Universitaria Policlinico of the Second University of Naples (n. 94 on 21 January 2014) in compliance with the Helsinki Declaration. The informed consent for the participation to the study was approved and signed by the parents of the children. Protein extraction and western blot analysis Protein extraction was performed on snow for 30?min using lyses-buffer with protease-inhibitors. Total proteins concentration was established using Bradford assay (Bio-Rad). 30?μg of total proteins was operate on 10?% polyacrylammide gel and blotted onto PVDF membrane (Millipore Marlborough MA). Immunoblotting was performed using major antibodies against EZH2 (C-1) EED (H-300) SUZ12 (D-10) Bcl2 (C-2) (Santacruz Biotechnology INC). Major antibodies AKT pAKT ERK benefit had been from Cell Signaling. All supplementary antibodies had been from Santa Cruz Biotecnology. JIB-04 All antibodies had been JIB-04 used in compliance with manifacturer’s guidelines. Bands had been visualized utilizing a chemiluminescent program (ECL-Amersham). The strength of each music group was determined utilizing a CCD camcorder and Amount One 1-D evaluation software (Biorad Laboratories). Outcomes had been normalized against the amount of β-tubulin (Santa Cruz Biotechnologies) manifestation in each test. It was acquired a variety of manifestation of the rings from 0 to 175?% having a median worth of 60?%. We’ve decided on intensity ideals greater than JIB-04 60 Therefore?% to be able to consider the manifestation of the various protein as high. Ideals from the intensities associated to the precise rings of the various protein equivalent or decrease to 60?% had been regarded JIB-04 as low manifestation. RNA removal and quantitative real-time PCR Total RNA was extracted from cell ethnicities using TRI REAGENT (Molecular Study Middle Inc. OH USA) based on the manufacturer’s process. RNA from bone tissue marrow at analysis was extracted with RNeasy FFPE package (Invitrogen). The reactions had been operate on an ABI PRISM?7900HT Series Detection Program; the cycling circumstances had been 10?min in 95?°C accompanied by 40?cycles of 15?s in 94?°C and 1?min in 68?°C. In the first step we established the stability of the control gene (β-actin) for the normalization from the real-time PCR items. Specific.

Monday, October 24, 2016 2:55 PM|Tasian, S. K., Teachey, D. T., Li, Y., Shen, F., Harvey, R. C., Chen, I.-M., Ryan, T., Vincent, T. L., Willman, C. L., Perl, A. E., Hunger, S. P., Loh, M. L., Carroll, M., Grupp, S. A.|BLOOD First Edition Papers|Labels: AKT, ALL

Philadelphia chromosome-like B-cell lymphoblastic leukemia (BCR-ABL1-like or Ph-like ALL) is associated with activated JAK/STAT, SRC/ABL, and/or PI3K/Akt/mTOR signaling and poor clinical outcomes. Inhibitors of PI3K pathway signaling (PI3Ki) have been minimally investigated in Ph-like ALL to date. We hypothesized that targeted inhibition of PI3Kα, PI3K, PI3K/mTOR, or TORC1/TORC2 would decrease leukemia proliferation and abrogate aberrant kinase signaling. We further hypothesized that combined PI3K pathway and JAK inhibition or PI3K pathway and SRC/ABL inhibition would have superior efficacy compared to inhibitor monotherapy. We treated ten childhood ALL patient-derived xenograft models harboring various Ph-like genomic alterations with four discrete PI3K pathway protein inhibitors and observed marked leukemia reduction and in vivo signaling inhibition in all models. Treatment with the dual PI3K/mTOR inhibitor gedatolisib resulted in near-eradication of ALL in CRLF2/JAK-mutant models (n=7) with mean 92.2% (range 86.0-99.4%) reduction versus vehicle controls (p<0.0001) and in prolonged animal survival. Gedatolisib also inhibited ALL proliferation in ABL/PDGFR-mutant models (n=3) with mean 66.9% (range 42.0-87.6%) reduction versus vehicle (p<0.0001). Combined gedatolisib and ruxolitinib treatment of CRLF2/JAK-mutant models more effectively inhibited ALL proliferation than either inhibitor alone (p<0.001) and further enhanced survival. Similarly, superior efficacy of combined gedatolisib and dasatinib was observed in ABL/PDGFR-mutant models (p<0.001). Overall, PI3K/mTOR inhibition potently decreased ALL burden in vivo, and anti-leukemia activity was further enhanced with combination inhibitor therapy. Clinical trials testing combinations of kinase inhibitors in patients with Ph-like ALL are indicated.

Friday, October 21, 2016 6:48 PM|biopharama|Development of mTOR Inhibitors|Labels: AKT

Potential tumor suppressor p42 ErbB3-binding protein 1 (EBP1) inhibits phosphoinositide 3-kinase (PI3K) activity reducing the p85 regulatory subunit. of p42. Through identification of the smallest fragment of p42 that is responsible for its tumor suppressor activity our findings represent a novel approach for WZ811 targeted therapy of cancers that overexpress PI3K. Ebp1 an ErbB3 binding protein is the human homologue of the mouse protein p38-2AG4 which regulates cell proliferation1. The gene encoding p38-2AG4 and and and cell invasion assay in Matrigel chambers using U251MG cells or MDA-MB231 cells transfected with WZ811 GFP-tagged p42 constructs. As expected p42 extensively suppressed cell invasion approximately 80.64% and p42 fragments WZ811 strongly inhibited cell invasion as much as 70.08% of p42 (Fig. 4c left). Comparable result was obtained with MDA-MB231 cells (Fig. 4c right). Thus overexpression of the CTD fragment (280-394 aa) of p42 is sufficient for inhibition of cell invasion which is usually associated with the tumor suppressor activity of p42. To ascertain tumor suppressing activity of p42 results from CHIP-dependent p42-mediated p85 degradation we performed cell proliferation analysis and invasion assay in the presence of CHIP/HSP70. Overexpression of p42 only suppressed cell proliferation compared with vector control and co-transfection of CHIP/HSP70 with p42 or its fragments notably decreased growth rate in the both U251 and MDA-MB231 cells (Fig. 4d e) fitted with this immunoblotting that co-transfection of CHIP with p42 markedly reduced the endogenous p85 level (Fig. 4f) confirming that CHIP is necessary for p42-mediated p85 degradation. C-terminal domains of p42 down-regulates p85 proteins balance We previously discovered that elevated p42 appearance dramatically reduced p85 proteins amounts through managing p85 proteins stability by WZ811 marketing ubiquitination-dependent proteasomal degradation12. To examine whether p42 fragments wthhold the capability of p42 to mediate particular degradation WZ811 from the p85 subunit in cells we driven the half-life of p85 in the current presence of several p42 constructs. The half-life of p85 was markedly reduced in cells expressing full-length p42 or p42 fragments in comparison to control cells whereas p85 amounts were not changed by cyclohexaimide (CHX) treatment for 8 h in U251 glioma cells in keeping with earlier reports that p85 is definitely a relatively stable protein16 (Fig. 5a). Related results were acquired with MCF7 and MDA-MB231 breast malignancy cells (Fig. 5b). Number 5 C-terminal website of p42 disrupts p85 protein stability. To determine whether p42 fragments induce p85 instability through the same molecular mechanism with p42 WT we examined whether p85 is definitely ubiquitinated in the presence of p42 fragments as it is in the presence of p42 WT in glioma cells and breast malignancy cells (Fig. 5c). Manifestation of p42 fragments (183-394 and 280-394 aa) and p42 WT advertised p85 ubiquitination suggesting that CTD of p42 is responsible for interaction with the HSP70 and CHIP Eptifibatide Acetate E3 ligase complex (Fig. 5c) fitting with our observation that at least the 280-394 amino acids of p42 is necessary and required for the formation of a triple complex with HSP70 and CHIP. Therefore the CTD (280-394 aa) of p42 facilitates degradation WZ811 of p85 from the ubiquitin-proteasome pathway. Stepwise manifestation of p42-CTD downregulates p85 protein levels To evaluate whether p42 fragments are physiologically able to substitute for p42 WT in p85 degradation we depleted endogenous Ebp1 from cells using Si-Ebp1 and then reintroduced numerous GFP-Ebp1 constructs. Knockdown of Ebp1 was confirmed and quantified by immunoblotting (Fig. 6a) in U251 cells and breast cancer cells. Stepwise manifestation of p42 after depletion of endogenous Ebp1 provoked approximately 38.14% lesser p85 protein levels compared with control (Fig. 6b second lane). Moreover C-terminal website (183-394 and 280-394 aa fragments) of p42 experienced similar effects to p42 WT obviously reducing p85 protein levels (Fig. 6b fourth and 5th lanes). On the other hand exogenous p48 appearance pursuing silencing of Ebp1 didn’t alter p85 proteins amounts (Fig. 6b second street) in U251 cells and MCF7 and MDA-MB231 cells. Quantified data.

Wednesday, October 19, 2016 12:51 PM|Soler, A., Figueiredo, A. M., Castel, P., Martin, L., Monelli, E., Angulo-Urarte, A., Mila-Guasch, M., Vinals, F., Baselga, J., Casanovas, O., Graupera, M.|Clinical Cancer Research Online First Articles|Labels: AKT, mTOR, pancreatic cancer

Purpose: Mutations in the PI3K pathway occur in 16% of patients with pancreatic neuroendocrine tumors (PanNETs), which suggests that these tumors are an exciting setting for PI3K/AKT/mTOR pharmacologic intervention. Everolimus, an mTOR inhibitor, is being used to treat patients with advanced PanNETs. However, resistance to mTOR-targeted therapy is emerging partially due to the loss of mTOR-dependent feedback inhibition of AKT. In contrast, the response to PI3K inhibitors in PanNETs is unknown.

Experimental Design: In the current study, we assessed the frequency of PI3K pathway activation in human PanNETs and in RIP1-Tag2 mice, a preclinical tumor model of PanNETs, and we investigated the therapeutic efficacy of inhibiting PI3K in RIP1-Tag2 mice using a combination of pan (GDC-0941) and p110α-selective (GDC-0326) inhibitors and isoform-specific PI3K kinase-dead–mutant mice.

Results: Human and mouse PanNETs showed enhanced pAKT, pPRAS40, and pS6 positivity compared with normal tissue. Although treatment of RIP1-Tag2 mice with GDC-0941 led to reduced tumor growth with no impact on tumor vessels, the selective inactivation of the p110α PI3K isoform, either genetically or pharmacologically, reduced tumor growth as well as vascular area. Furthermore, GDC-0326 reduced the incidence of liver and lymph node metastasis compared with vehicle-treated mice. We also demonstrated that tumor and stromal cells are implicated in the antitumor activity of GDC-0326 in RIP1-Tag2 tumors.

Conclusion: Our data provide a rationale for p110α-selective intervention in PanNETs and unravel a new function of this kinase in cancer biology through its role in promoting metastasis. Clin Cancer Res; 1–13. ©2016 AACR.

Tuesday, October 18, 2016 2:36 PM|Cooney, J. D., Aguiar, R. C. T.|BLOOD First Edition Papers|Labels: AKT

Phosphodiesterase 4 (PDE4) inhibition restores the suppressive effects of cyclic-AMP in lymphocytes. In this concise review, we detail how PDE4 inhibition downmodulates the B-cell receptor (BCR)-related kinases SYK and PI3K, inhibits VEGFA secretion by tumor cells, inducing cancer cell apoptosis and blocking angiogenesis in the microenvironment. We describe the successful clinical repurposing of PDE4 inhibitors in B-cell malignancies, and propose that given their anti-inflammatory/immunomodulatory activity, these agents will suppress BCR signals without the toxicity associated with other targeted biological doublets.

Monday, October 17, 2016 12:09 PM|Gibson, W. J., Ruan, D. T., Paulson, V. A., Barletta, J. A., Hanna, G. J., Kraft, S., Calles, A., Nehs, M. A., Moore, F. D., Taylor-Weiner, A., Wala, J. A., Zack, T. I., Lee, T. C., Fennessy, F. M., Alexander, E. K., Tomas, T., Janne, P. A., Garraway, L. A., Carter, S. L., Beroukhim, R., Lorch, J. H., Van Allen, E.|Clinical Cancer Research Online First Articles|Labels: AKT, thymic

Purpose: Cancers may resist single-agent targeted therapies when the flux of cellular growth signals is shifted from one pathway to another. Blockade of multiple pathways may be necessary for effective inhibition of tumor growth. We document a case in which a patient with anaplastic thyroid carcinoma (ATC) failed to respond to either mTOR or combined RAF/MEK inhibition, but experienced a dramatic response when both drug regimens were combined. Experimental Design: Multi-region whole-exome sequencing of five diagnostic and four autopsy tumor biopsies was performed. Meta-analysis of DNA and RNA sequencing studies of ATC was performed. Results: Sequencing revealed truncal BRAF and PIK3CA mutations, which are known to activate the MAPK and PI3K/AKT pathways respectively. Meta-analysis demonstrated 10.3% co-occurrence of MAPK and PI3K pathway alterations in ATC. These tumors display a separate transcriptional profile from other ATC, consistent with a novel subgroup of ATC. Conclusions: BRAF and PIK3CA mutations define a distinct subset of ATC. Blockade of the MAPK and PI3K pathways appears necessary for tumor response in this subset of ATC. This identification of synergistic activity between targeted agents may inform clinical trial design in ATC.

Saturday, October 15, 2016 10:21 PM|Current Cancer Drug Targets (Volume 16 - Issue 8)|Labels: AKT, leukemia
Clinical trials in chronic lymphocytic leukemia (CLL) have focused mainly on younger fit patients until recently. However, CLL is a disease of elderly and many patients have significant comorbid conditions which together with advanced age preclude the use of aggressive regimens like FCR (fludarabine, cyclophosphamide, rituximab). Therefore, parameters such as performance status, renal function and number/severity of comorbidities together with clinical judgment should be used to guide the decision-making process regarding intensity of treatment. Two large randomized trials recently demonstrated that addition of monoclonal anti-CD20 antibodies (obinutuzumab, rituximab, and ofatumumab) to chlorambucil in untreated comorbid patients lead to improvement in complete remission rate, progression-free survival and even overall survival (obinutuzumab-chlorambucil and rituximab-chlorambucil), with acceptable toxicity profile. Thus, chemoimmunotherapy combining chlorambucil with an anti-CD20 antibody is the new standard approach for elderly/comorbid CLL patients in the first line. Treatment of relapsed/refractory disease in this patient population is very challenging and data regarding this subpopulation are rather limited. Impressive efficacy of novel targeted small molecules interfering with B-cell receptor signaling, namely Bruton tyrosine kinase inhibitor ibrutinib and phosphatidylinositol-3 kinase delta inhibitor idelalisib, radically changed the treatment paradigms for relapsed/refractory CLL; relatively mild toxicity of these agents make them very good candidates for elderly/comorbid patients. Other options for relapsed/refractory disease include alemtuzumab, ofatumumab, high-dose glucocorticoids+rituximab and bendamustine+rituximab. This review summarizes the current knowledge on prognostication and therapy of elderly and comorbid patients with CLL.
Saturday, October 15, 2016 10:21 PM|Current Cancer Drug Targets (Volume 16 - Issue 8)|Labels: AKT, FGFR, leukemia
There have been significant advances in our understanding of the pathogenesis of chronic lymphocytic leukemia (CLL) over the last decade, which has been accompanied by a rapid increase in treatment options. Inhibitors of BCRsignaling such as ibrutinib and idelalisib, and pro-apoptotic agents such as ABT- 199 have shown great promise in initial clinical trials and have been at the forefront of recent developments. However, despite the encouraging early data, these agents do not appear to represent a “cure” for CLL and mechanisms of resistance to these agents have already been identified. In light of these considerations there remains a need for alternative treatment strategies. Lenalidomide, a second-generation derivative of thalidomide, has been demonstrated to have significant clinical activity in CLL. Its effect appears to be mediated by reduction of CLL-cell proliferation, improvement of anti-tumor immune responses and reduction of pro-tumoral factors in the CLL microenvironment. This review discusses our current understanding of the mechanism of action of lenalidomide on both healthy cells and in CLL. It also summarises the published clinical trial experience with this drug, and proposes an ongoing role for this agent in the CLL armamentarium.
Saturday, October 15, 2016 10:21 PM|Current Cancer Drug Targets (Volume 16 - Issue 8)|Labels: AKT, P53, leukemia
Despite impressive therapeutic progress represented by the advent of chemoimmunotherapy, chronic lymphocytic leukemia (CLL) remains incurable by conventional modalities. Refractory CLL defined by non-response to treatment or relapse/progression within 6 months is associated with multiple unfavourable prognostic factors such as p53 pathway disruption, deteriorating patient condition, increased risk of severe infections, and poor response to treatment, resulting in a very short overall survival. Therefore, refractory CLL represents a highly challenging situation for the hematologist as well as the patient. The amount and quality of data on refractory CLL are rather limited as clinical trials usually combine patients with relapsed and refractory disease. Therapeutic options for refractory CLL include alemtuzumab, ofatumumab, fludarabine- and bendamustine-based regimens, platinum-based aggressive protocols and high-dose corticosteroids combined with monoclonal antibodies. The recent introduction of ibrutinib and idelalisib, small molecules interfering with B-cell receptor pathways, revolutionized the treatment of refractory CLL by the novel concept of long-term, oral treatment leading to impressive progression-free and overall survival improvement. Allogeneic stem cell transplantation is still considered the only option with curative potential. This review focuses on the currently available therapeutic strategies for refractory CLL.
Wednesday, October 12, 2016 3:28 PM|Head and Neck Oncology|Labels: AKT, EGFR, mTOR, RAS, STAT, VEGF, WNT, HNN
Recent advances in genomics, proteomics, bioinformatics and systems biology have unraveled the complex aberrant signaling networks in cancer. The knowledge accrued has dramatically increased the opportunities for discovery of novel molecular targets for drug development. Major emphasis is being laid on designing new therapeutic strategies targeting multiple signaling pathways for more effective disease management. However, the translation of in vitro findings to patient management often poses major challenges that limit their clinical efficacy. Here we will discuss how understanding the dysregulated signaling networks can explain the pitfalls in translating the laboratory findings from the bench-to-bedside and suggest novel approaches to overcome these problems using head and neck cancer as a prototype. The five year survival rates of HNSCC patients (about 50% at 5 years) have not improved significantly despite advancements in multimodality therapy including surgery, radiation and chemotherapy. Molecular targeted therapies with inhibitors of EGFR and VEGF either alone, or in combination with conventional treatments have shown limited improved efficacy. The key deregulated signaling pathways in head and neck squamous cell carcinoma (HNSCC) include EGFR, Ras, TGFβ, NFκB, Stat, Wnt/β-catenin and PI3-K/AKT/mTOR. The aberrant activities of these interrelated signaling pathways contribute to HNSCC development. In depth understanding of the cross-talks between these pathways and networks will form the basis of developing novel strategies for targeting multiple molecular components for more effective prevention and treatment of HNSCC.
Wednesday, October 12, 2016 3:28 PM|Head and Neck Oncology|Labels: AKT, brain cancer, biomarker diagnostic, clinical trial
ARID1A plays an important role in malignant tumorigenesis, but its role in gliomas remains unclear. This study aims to identify a possible biomarker that could be used in the diagnosis and tumor grade assessment of gliomas. Additionally, the biological role of ARID1A was further characterized in glioma cells. Data was collected from sporadic gliomas specimens (n = 55) and normal brain tissues (n = 5), and ARID1A expression was examined by quantitative RT PCR and western blot. We verified the differential expression of ARID1A and evaluated the associations of ARID1A expression with the pathologic characteristics of gliomas. An ARID1A overexpression plasmid was constructed and transfected into the human glioblastoma cell line U87, and cell proliferation and apoptosis were examined. Our results showed that the ARID1A mRNA in gliomas was significantly down regulated compared to that in normal brain tissues. As the pathological grade (World Health Organization (WHO) classification 2007) increased, the expression of ARID1A is decreased. Overexpression of ARID1A was able to inhibit cell proliferation and arrest cell cycle progression in the G1/S phase, as well as induce cell apoptosis in glioma cells. Furthermore, ARID1A overexpression was accompanied by suppression of glioma cell proliferation via the PI3K pathway and decreased expression of pAKT and pS6K. Therefore, ARID1A may be a useful target for the diagnosis and therapy of gliomas.
Wednesday, October 12, 2016 3:26 PM|Dineo Khabele, Syeda M Kabir, Yuanlin Dong, Eunsook Lee, Valerie Montgomery Rice, Deok-Soo Son|Journal of Cancer|Labels: AKT, EGFR, ovarian cancer

Objective: Overexpression of the epidermal growth factor receptor (EGFR) is associated with the malignant phenotype in many cancers including ovarian cancer, which leads to increased cell proliferation and survival. In spite of emerging EGFR inhibitors as a potentially useful agent, they are largely ineffective in patients with advanced or recurrent ovarian cancers. Since Akt as a key downstream factor of EGFR is highly activated in some high grade serous ovarian tumors, the augmented Akt activation may attribute to irregular EGFR-mediated signaling observed in ovarian cancer. Here we investigated the differential effect of Akt on the EGF-induced cell viability in a panel of ovarian cancer cell lines.

Methods: Cellular viability assay and western blot analysis were used to measure cell viability and expression levels of proteins, respectively. Knockdown of Akt was achieved with siRNA and stable transfection of expression vectors was performed.

Results: Cellular viability increased in OVCAR-3 ovarian cancer cells exposed to EGF, but little to no difference was observed in the 5 other ovarian cancer cells including SKOV-3 cells despite of the expression of EGFR. In OVCAR-3 cells, EGF activated Erk and Akt, but an Erk inhibitor had no impact on cellular viability. On the other hand, the EGFR and PI3K inhibitors decreased EGF-induced cellular viability, indicating the involvement of Akt signaling. Although EGF activated Erk in SKOV-3 cells, the Akt activation was very weak as compared to OVCAR-3 cells. Furthermore, we observed a different expression of Akt isoforms: Akt1 was constitutively expressed in all tested ovarian cancer cells, while Akt3 was little expressed. Interestingly, Akt2 was highly expressed in OVCAR-3 cells. Knockdown of Akt2 blocked EGF-induced OVCAR-3 cell viability whereas knockdown for Akt1 and Erk1/2 had no significant effect. Stable transfection of Akt2 into SKOV-3 cells phosphorylated more Akt and enhanced cell viability in response to EGF.

Conclusions: Akt2-dependent signaling appears to play an important role in EGFR-mediated cellular viability in ovarian cancer and targeting specific Akt isoform may provide a potential therapeutic approach for EGFR-expressing ovarian cancers.

Wednesday, October 12, 2016 3:26 PM|Shyam Babu Prasad, Suresh Singh Yadav, Mitali Das, H. B. Govardhan, Lakshmi Kant Pandey, Sunita Singh, Satyajit Pradhan, Gopeshwar Narayan|Journal of Cancer|Labels: AKT, HDAC, cervical cancer

The Forkhead transcription factor FOXO1, an important downstream target of phosphatidylinositol-3-kinase (PI3K)/AKT signaling pathway, regulates cellular homeostasis by maintaining cell proliferation, apoptosis and viability in normal cells. Though, the function and regulation of FOXO1 is well documented in many cancers, the molecular mechanism of its regulation in cervical cancer is largely unknown. In the present study we have investigated the role of PI3K inhibition on FOXO1 regulation. Expression profiling of primary tumors and cell lines show over expression of PIK3CA and AKT1; and down regulation of FOXO1. Lack of FOXO1 promoter methylation and inability of hypomethylating drug 5-Aza-2'-deoxycytidine and HDAC inhibitor trichostatin A to reactivate FOXO1 expression suggest that loss of FOXO1 expression is due to mechanisms other than promoter methylation/acetylation. Inhibition of PI3K by LY294002 decreased the level of p-AKT1 and activated FOXO1 transcription factor. We demonstrate that activation of FOXO1 induces apoptosis, cell proliferation arrest, and decreased cell viability in cervical cancer cell lines. Our data suggest that frequent down regulation of FOXO1 and its functional inactivation may be due to post-translational modifications in cervical cancer. Together, these observations suggest that activation of FOXO1 and its nuclear sequestration is critical in the regulation of cell proliferation, cell viability and apoptosis in cervical cancer. Hence, PI3K/AKT pathway may be a potential molecular target for cervical cancer therapy.

Wednesday, October 12, 2016 3:26 PM|Grazielle M. Ferreira, Marcelo Martinez, Isabel Cristina C. Camargo, Raquel F. Domeniconi, Francisco Eduardo Martinez, Luiz Gustavo A. Chuffa|Journal of Cancer|Labels: AKT, MapK, mTOR, ovarian cancer

Epidermal growth factor receptors 2 (Her-2) and 4 (Her-4) are closely associated with ovarian cancer (OC) progression and metastasis, and a more complete understanding of these signaling pathways allow the development of new therapeutic strategies. Melatonin (Mel) is recognized as having several anticancer properties and has been reported to modulate Her-2 system in aggressive tumors. Here, we investigated OC and the role of Mel therapy on the Her-2- and Her-4-signaling pathway related to downstream molecules in an ethanol-preferring rat model. To induce OC, the left ovary was injected directly with a single dose of 100 µg 7,12-dimethylbenz(a)anthracene (DMBA) dissolved in 10 µL of sesame oil under the bursa. Right ovaries were used as sham-surgery controls. After developing OC, half of the animals received i.p. injections of Mel (200 µg/100 g b.w./day) for 60 days. While Mel therapy was unable to reduce Her-4 and phosphoinositide 3-kinase (PI3K) levels, it was able to suppress the OC-related increase in the levels of the Her-2, p38 mitogen-activated protein kinases (p38 MAPK), protein kinase B (phospho-AKT), and mammalian target of rapamycin (mTOR). In addition, Mel significantly attenuated the expression of Her-2, p38 MAPK, and p-AKT, which are involved in OC signaling during ethanol intake. Collectively, our results suggest that Mel attenuates the Her-2-signaling pathway in OC of ethanol-preferring rats, providing an effective contribution for further development of adjuvant therapies.

Wednesday, October 12, 2016 3:26 PM|Artur Jurczyszyn, Anna Zebzda, Jacek Czepiel, William Perucki, Stanisława Bazan-Socha, Dorota Cibor, Danuta Owczarek, Marcin Majka|Journal of Cancer|Labels: AKT, MM, clinical trial

Introduction. Geldanamycin (GA) is an ansamycin antibiotic that exhibits potent anti-neoplastic properties. The aim of this study was to assess the impact of GA and its derivatives on the growth and invasiveness of myeloma cell lines and CD138+ cells derived from the bone marrow of patients with multiple myeloma.

Materials and methods. We evaluated cell proliferation, survival, apoptosis, cell cycle of myeloma cells, and the expression of cell surface proteins after incubation with geldanamycin or its derivatives.

Results. GA and its analogs have an effect on myeloma cells by inhibiting their growth in a time and dose-dependent manner. Myeloma cell lines demonstrated decreased proliferation after incubation with 10 nM of GA or 100 nM GA analogs. The first significant effects of GA on U266 cells was observed after 24 hours. After 24 hours, U266 cells incubated with 100 nM GA were in both early and late stages of apoptosis; 17AEP and 17DMAG caused apoptosis of similar intensity to GA. It has been observed that GA and its derivatives cause caspase-3 activation. Analysis of the activity of AKT and MAP 42/44 kinases was performed by incubating U266 cells for 24 and 48 hours in100 nM of GA and its derivatives. After 24 hours incubation, no significant changes in protein expression were observed, while after 48 hours, the strongest changes were seen in AKT protein expression after incubation with GA and 17AEP-GA. In studies of the cell cycle, it was found that 100 nM 17AEP-GA and 17-DMAP-GA cause cell cycle abnormalities. We observed a nearly two-fold increase in U266 cells in the G1 phase and a simultaneous decrease in the percentage of cells in the G2/M phase, indicating that cells were halted in the G1 phase. In the case of the INA6 cells, proliferation was halted in both the G1 and G2/M phases.

Conclusions. GA and the analogues that we tested can inhibit myeloma cell growth by induction of apoptosis and blockage of cell cycle progression, and have an effect on the down-regulation of the MET receptor. The GA derivatives tested, despite their modifications still retain strong anticancer properties. Specifically, two analogues of GA, 17AEP-GA and 17DMAG due to their properties can be more effective and safer chemotherapeutic agents than 17AAG, which is currently used and described in literature.

Wednesday, October 12, 2016 3:26 PM|Zhenwei Zhang, Lei Miao, Xin Wu, Guangze Liu, Yuting Peng, Xiaoming Xin, Binghua Jiao, Xiangping Kong|Journal of Cancer|Labels: AKT, mTOR, gastric, clinical trial

Carnosine (β-alanyl-L-histidine), described as an enigmatic peptide for its antioxidant, anti-aging and especially antiproliferation properties, has been demonstrated to play an anti-tumorigenic role in certain types of cancer. However, its function in human gastric carcinoma remains unclear. In this study, the effect of carnosine on cell proliferation and its underlying mechanisms were investigated in the cultured human gastric carcinoma cells. The mTOR signaling axis molecules were analyzed in carnosine treated cells. The results showed that treatment with carnosine led to proliferation inhibition, cell cycle arrest in the G0/G1 phase, apoptosis increase, and inhibition of mTOR signaling activation by decreasing the phosphorylation of Akt, mTOR and p70S6K, suggesting that proliferation inhibition of carnosine in human gastric carcinoma was through the inhibition of Akt/mTOR/p70S6K pathway, and carnosine would be a mimic of rapamycin.

Wednesday, October 12, 2016 3:26 PM|V. Hearing|JournalTOCs API - Journal of Investigative Dermatology (875 articles)|Labels: AKT, melanoma, skin cancer

464 Overexpression of NUAK2 has a significant impact on the survival of acral melanoma patients
T. Namiki M. Funazaumi, K. Nojima, M. Ishikawa, A. Tanemura, I. Katamaya, T. Mori, N. Yamazaki, H. Yokozeki, V. Hearing
Journal of Investigative Dermatology, Vol. 136, No. 9 (2016) pp. S239 -
We previously reported that amplification of the AMPK-related kinase NUAK2 was involved in regulating the proliferation and migration of human melanoma cells (PNAS2011) and that pharmacologic inhibition of CDK2 was sufficient to suppress the growth of NUAK2 amplified and PTEN-deficient melanoma cells (Cancer Res 2015). Furthermore, those previous data by the analysis of 56 specimens from primary acral melanoma tumors suggested that over-expression of both NUAK2 and phospho-Akt(S473) had a significant impact on the relapse-free survival of acral melanoma patients.

Wednesday, October 12, 2016 3:26 PM|D. Kulms|JournalTOCs API - Journal of Investigative Dermatology (875 articles)|Labels: AKT, melanoma, skin cancer

456 Mechanistic insight into the consequences of sublethal drug doses and the tumor microenvironment on therapeutic responses and unwanted metastatic outgrowth of malignant melanoma
G. Del Mistro S. Beissert, D. Kulms
Journal of Investigative Dermatology, Vol. 136, No. 9 (2016) pp. S238 -
In response to conventional therapeutic treatment malignant melanoma represent with high relapse rates coinciding with pronounced metastatic outgrowth. The present study aims to investigate the impact of lethal as well as sublethal drug doses on long term cancer cell survival and tumor relapse. It also addresses the influence of the tumor microenvironment (fibroblasts versus astrocytes) on therapeutic responses of metastatic melanoma. First results imply that the signalling network within melanoma cells is prone to modifications upon treatment with sublethal drug doses by differentially altering the activation status of survival proteins, including NFκB, IκBα, AKT, ERK, and JNK.

Wednesday, October 12, 2016 3:26 PM|Fred Hutchinson Cancer Research Center/UW Medicine Cancer Consortium - Clinical Trials|Labels: AKT, INT, mTOR, clinical trial
SF1126 is a novel inhibitor of PI3 kinase and mTOR that includes an active moiety (consisting of LY294002) linked to an RGDS tetrapeptide that targets the active agent to integrin expressing tissues. In this first pediatric phase 1 trial of SF1126, dose escalation will follow a 3+3 dose escalation design. Once a recommended phase 2 pediatric dose is identified, an expansion cohort of 10 patients with tumors with MYCN amplification, Mycn expression, or Myc expression will be treated.
Wednesday, October 12, 2016 3:26 PM|Fred Hutchinson Cancer Research Center/UW Medicine Cancer Consortium - Clinical Trials|Labels: AKT, prostate cancer, clinical trial
This is a phase I, open-label, multicentre study of AZD8186 administered orally in patients with advanced castrate-resistant prostate cancer (CRPC), squamous non-small cell lung cancer (sqNSCLC), triple negative breast cancer (TNBC) and known PTEN-deficient advanced solid malignancies. The study design allows an escalation of dose with intensive safety monitoring to ensure the safety of the patients. There are two parts to this study: Part A, dose escalation, and Part B, expansion cohort(s) at the intended therapeutic dose(s).
Wednesday, October 12, 2016 3:26 PM|Fred Hutchinson Cancer Research Center/UW Medicine Cancer Consortium - Clinical Trials|Labels: AKT, breast cancer, clinical trial
The purpose of the study is to determine whether treatment with a PI3K inhibitor plus letrozole leads to an increase in pathologic response compared to treatment with placebo plus letrozole in patients with Breast cancer
Wednesday, October 12, 2016 3:26 PM|Zuoquan Xie, Young H. Lee, Marta Boeke, Lucia B. Jilaveanu, Zongzhi Liu, Donald P. Bottaro, Harriet M. Kluger, Brian Shuch|Journal of Cancer|Labels: AKT, MapK, MET, mTOR, VEGF, kidney cancer

Background: Clear cell renal cell carcinoma (ccRCC) is the most lethal form of kidney cancer. Small molecule VEGFR inhibitors are widely used but are not curative and various resistance mechanisms such as activation of the MET pathway have been described. Dual MET/VEGFR2 inhibitors have recently shown clinical benefit but limited preclinical data evaluates their effects in ccRCC.

Methods: An interrogation of the Cancer Genome Atlas (TCGA) dataset was performed to evaluate oncogenic alterations in the MET/VEGFR2 pathway. We evaluated the in vitro effects of Cabozantinib, a dual MET/VEGFR2 inhibitor, using a panel of ccRCC cell lines. Drug effects of cell viability and proliferation, migration, cell scatter, anchorage independent growth, and downstream MET/VEGFR2 signaling pathways were assessed.

Results: Twelve percent of TCGA cases had possible MET/HGF oncogenic alterations with co-occurrence noted (p<0.001). MET/HGF altered cases had worse overall survival (p=0.044). Cabozantinib was a potent inhibitor of MET and VEGFR2 in vitro in our cell line panel. PI3K, MAPK and mTOR pathways were also suppressed by cabozantinib, however the effects on cell viability in vitro were modest. At nanomolar concentrations of cabozantinib, HGF-stimulated migration, invasion, cellular scattering and soft agar colony formation were inhibited.

Conclusions: We provide further preclinical rationale for dual MET/VEGFR2 inhibition in ccRCC. While the MET pathway is implicated in VEGFR resistance, dual inhibitors may have direct anti-tumor effects in a patient subset with evidence of MET pathway involvement. Cabozantinib is a potent dual MET/VEGFR2 inhibitor, significantly inhibits cell migration and invasion in vitro and likely has anti-angiogenic effects similar to other VEGFR tyrosine kinase inhibitors. Future work involving in vivo models will be useful to better define mechanisms of potential anti-tumor activity.

Wednesday, October 12, 2016 3:26 PM|Hua Wang, Hao Lin, Jincheng Pan, Chengqiang Mo, Faming Zhang, Bin Huang, Zongren Wang, Xu Chen, Jintao Zhuang, Daohu Wang, Shaopeng Qiu|Journal of Cancer|Labels: AKT, prostate cancer

BACKGROUND. Aggressive tumor cells can form perfusable networks that mimic normal vasculature and enhance tumor growth and metastasis. A number of molecular players have been implicated in such vasculogenic mimicry, among them the receptor tyrosine kinase EphA2, which is aberrantly expressed in aggressive tumors. Here we study the role and regulation of EphA2 in vasculogenic mimicry in prostate cancer where this phenomenon is still poorly understood.

METHODS. Vasculogenic mimicry was characterized by tubules whose cellular lining was negative for the endothelial cell marker CD34 but positive for periodic acid-Schiff staining, and/or contained red blood cells. Vasculogenic mimicry was assessed in 92 clinical samples of prostate cancer and analyzed in more detail in three prostate cancer cell lines kept in three-dimensional culture. Tissue samples and cell lines were also assessed for total and phosphorylated levels of EphA2 and its potential regulator, Phosphoinositide 3-Kinase (PI3K). In addition, the role of EphA2 in vasculogenic mimicry and in cell migration and invasion were investigated by manipulating the levels of EphA2 through specific siRNAs. Furthermore, the role of PI3K in vasculogenic mimicry and in regulating EphA2 was tested by application of an inhibitor, LY294002.

RESULTS. Immunohistochemistry of prostate cancers showed a significant correlation between vasculogenic mimicry and high expression levels of EphA2, high Gleason scores, advanced TNM stage, and the presence of lymph node and distant metastases. Likewise, two prostate cancer cell lines (PC3 and DU-145) formed vasculogenic networks on Matrigel and expressed high EphA2 levels, while one line (LNCaP) showed no vasculogenic networks and lower EphA2 levels. Specific silencing of EphA2 in PC3 and DU-145 cells decreased vasculogenic mimicry as well as cell migration and invasion. Furthermore, high expression levels of PI3K and EphA2 phosphorylation at Ser897 significantly correlated with the presence of vasculogenic mimicry and in vitro inhibition of PI3K by LY294002 disrupted vasculogenic mimicry, potentially through a reduction of EphA2 phosphorylation at Ser897.

CONCLUSIONS. The expression levels of PI3K and EphA2 are positively correlated with vasculogenic mimicry both in vivo and in vitro. Moreover, phosphorylation levels of EphA2 regulated by PI3K are also significantly associated with vasculogenic mimicry in vivo. Based on its functional implication in vasculogenic mimicry in vitro, EphA2 signaling may be a potential therapeutic target in advanced prostate cancer.

Wednesday, October 12, 2016 3:26 PM|Cheng-Zhi Qiu, Ming-Zhen Wang, Wai-Shi Yu, Yan-Ta Guo, Chun-Xiao Wang, Xiao-Feng Yang|Journal of Cancer|Labels: AKT, WNT, CRC

Objective: Overexpression of GOLPH3 in colorectal cancer tissue may promote cell proliferation and activate the Wnt signaling pathway. We investigated the correlation between GOLPH3 gene expression and the Wnt signaling pathway to explore the mechanism of the overexpression of GOLPH3 gene which promotes proliferation in human colon cancer cells.

Methods: We measured expression of GOLPH3 mRNA in the human colon cancer cell lines HCT116, HT29, SW480 and SW620 by RT-PCR, and the cells with the highest expression were selected and divided into four groups: negative control, GOLPH3 siRNA transfection (siRNA-GOLPH3), Akt inhibitor (Tricinbine), and glycogen synthase kinase (GSK)-3β inhibitor (TWS119). After human colon cancer cells were transfected with siRNA-GOLPH3, we used RT-PCR to investigate the silencing effect of GOLPH3 gene. We assessed the activity of the Wnt signaling pathway in all groups using the Topflash method. Proliferation and apoptosis of colon cancer SW620 cells were detected by MTT assay, colony formation assay and flow cytometry. Expression of Golgi phosphoprotein (GOLPH)3, β-catenin, GSK-3β and pS9-GSK-3β in cancer cells was determined by Western blotting.

Results: SW620 cells expressed the highest level of GOLPH3 mRNA, and the silence effect was good after they were transfected with siRNA-GOLPH3. The relative luminescence units (RLU) values in the experimental groups were significantly lower than in the negative control group (P<0.001). There was no significant difference in the RLU values among the experimental groups (P> 0.05). The growth inhibition ratio and apoptosis rate of cancer cells in each experimental group were significantly higher than those in the control group, and the cell colony count in the experimental group was significantly lower than in the control group (P<0.05). In addition, the RLU value, proliferation and apoptosis rate of cancer cells did not differ significantly between each two experimental groups. Western blotting showed that, compared with the control group, expression of β-catenin and pS9-GSK3 proteins were significantly decreased in the experimental group. Expression of GSK-3β in the experimental group did not different from that of the control group.

Conclusions: Overexpression of GOLPH3 gene activated the Wnt signaling pathway, as well as increasing expression of β-catenin, promoting proliferation and inhibiting apoptosis in human colon cancer cells. The mechanism of action was that overexpression of GOLPH3 gene activated Akt, which may also further activate the Wnt signaling pathway via GSK-3β, and promote proliferation in human colon cancer cells.

Wednesday, October 12, 2016 3:26 PM|Ivette J. Suárez-Arroyo, Tiffany J. Rios-Fuller, Yismeilin R. Feliz-Mosquea, Mercedes Lacourt-Ventura, Daniel J. Leal-Alviarez, Gerónimo Maldonado-Martinez, Luis A. Cubano, Michelle M. Martínez-Montemayor|Journal of Cancer|Labels: AKT, EGFR, breast cancer

The high incidence of resistance to Tyrosine Kinase Inhibitors (TKIs) targeted against EGFR and downstream pathways has increased the necessity to identify agents that may be combined with these therapies to provide a sustained response for breast cancer patients. Here, we investigate the therapeutic potential of Ganoderma lucidum extract (GLE) in breast cancer, focusing on the regulation of the EGFR signaling cascade when treated with the EGFR TKI, Erlotinib. SUM-149, or intrinsic Erlotinib resistant MDA-MB-231 cells, and a successfully developed Erlotinib resistant cell line, rSUM-149 were treated with increasing concentrations of Erlotinib, GLE, or their combination (Erlotinib/GLE) for 72h. Treatment effects were tested on cell viability, cell proliferation, cell migration and invasion. To determine tumor progression, severe combined immunodeficient mice were injected with SUM-149 cells and then treated with Erlotinib/GLE or Erlotinib for 13 weeks. We assessed the protein expression of ERK1/2 and AKT in in vitro and in vivo models. Our results show that GLE synergizes with Erlotinib to sensitize SUM-149 cells to drug treatment, and overcomes intrinsic and developed Erlotinib resistance. Also, Erlotinib/GLE decreases SUM-149 cell viability, proliferation, migration and invasion. GLE increases Erlotinib sensitivity by inactivating AKT and ERK signaling pathways in our models. We conclude that a combinatorial therapeutic approach may be the best way to increase prognosis in breast cancer patients with EGFR overexpressing tumors.

Wednesday, October 12, 2016 3:24 PM|Florian Ewald, Dominik Nörz, Astrid Grottke, Johanna Bach, Christiane Herzberger, Bianca T. Hofmann, Björn Nashan, Manfred Jücker|Journal of Cancer (RSS 2.0)|Labels: AKT, mTOR, liver cancer

Hepatocellular carcinoma (HCC) is the sixth most common cancer, and the third most common cause of cancer related death worldwide. The multi-kinase inhibitor Sorafenib represents the only systemic treatment option until today, and results from clinical trials with allosteric mTOR inhibitors were sobering. Since the PI3K/AKT/mTOR and RAF/MEK/ERK signaling pathways are frequently upregulated in HCC, we have analyzed the effects of AKT inhibitor MK-2206, MEK inhibitor AZD6244 (ARRY 142886) and mTOR kinase inhibitor AZD8055, given as single drugs or in combination, on proliferation and apoptosis of three HCC cell lines in vitro. We show that all three inhibitor combinations synergistically inhibit proliferation of the three HCC cell lines, with the strongest synergistic effect observed after vertical inhibition of AKT and mTORC1/2. We demonstrate that AKT kinase activity is restored 24h after blockade of mTORC1/2 by increased phosphorylation of T308, providing a rationale for combined targeting of AKT and mTOR inhibition in HCC. Our data suggest that a combination of inhibitors targeting those respective pathways may be a viable approach for future application in patients with hepatocellular carcinoma.

Wednesday, October 12, 2016 3:24 PM|Jangsoon Lee, Rachael Galloway, Geoff Grandjean, Justin Jacob, Juliane Humphries, Chandra Bartholomeusz, Samantha Goodstal, Bora Lim, Geoffrey Bartholomeusz, Naoto T. Ueno, Arvind Rao|Journal of Cancer (RSS 2.0)|Labels: AKT, breast cancer

Triple-negative breast cancer (TNBC) is a major cause of death among breast cancer patients that results from intrinsic and acquired resistance to systemic chemotherapies. To identify novel targets for effective treatment of TNBC through combination strategies with MEK inhibitor (AS703026), we used a novel method of combining high-throughput two- and three-dimensional (2D and 3D) RNAi screening. TNBC cells were transfected with a kinome siRNA library comprising siRNA targeting 790 kinases under both 2D and 3D culture conditions with or without AS703026. Molecule activity predictor analysis revealed the PI3K pathway as the major target pathway in our RNAi combination studies in TNBC. We found that PI3K inhibitor SAR245409 (also called XL765) combined with AS703026 synergistically inhibited proliferation compared with either drug alone (P < 0.001). Reduced in vitro colony formation (P < 0.001) and migration and invasion ability were also observed with the combination treatment (P<0.01). Our data suggest that SAR245409 combined with AS703026 may be effective in patients with TNBC. We conclude that a novel powerful high-throughput RNAi assays were able to identify anti-cancer drugs as single or combinational agents. Integrated and multi-system RNAi screening methods can complement difference between in vitro and in vivo culture conditions, and enriches targets that are close to the in vivo condition.

Wednesday, October 12, 2016 3:24 PM|Elif Baltaci, Seda Ekizoglu, Elif Sari, Emin Karaman, Turgut Ulutin, Nur Buyru|Journal of Cancer (RSS 2.0)|Labels: AKT, HNN

Squamous cell carcinoma of the head and neck (HNSCC) is among the most frequent cancers worldwide. The etiology and pathogenesis of HNSCC are influenced by multiple genetic factors in addition to environmental and lifestyle-related factors. However, the mechanism underlying the HNSCC is still far from clear.

The membrane associated gene CT120 was previously identified from chromosome 17p13.3 as a lung cancer-associated gene. Its function as an activator of the Erk and Akt signaling pathways in human lung cancer cell lines suggested that CT120 has an oncogenic function. However, there is no data in the literature on the role of CT120 in any other cancer type. Therefore, the aim of this study was to determine the expression rate and probable function of CT120 in HNSCC.

Tumor tissues from 50 patients were analyzed by real-time quantitative RT-PCR to investigate the expression rate and by direct sequencing to differentiate the CT120A and CT120B variants. CT120 overexpression was observed in 58% of tumors compared to non-cancerous tissue samples and this up-regulation was directly associated with the upregulation of the CT120A variant and with the stage of the disease (p=0.001).

Our results indicate that the CT120 gene may function in the development of HNSCC.

Wednesday, October 12, 2016 3:24 PM|Tieying Dong, Zhaoliang Liu, Shu Zhao, Chengyi Hu, Yupeng Liu, WenJie Ma, Qingyuan Zhang|Journal of Cancer (RSS 2.0)|Labels: AKT, lymphoma

Background: Follicular lymphoma (FL) frequently develops drug-resistance and transforms into more aggressive subtypes over time. It is urgent to find prognostic biomarkers and disclose signaling pathways that have potential to be drug targets. In this study, we investigated the association of FL prognosis with the expression of 2 proteins: PIK3CD, a PI3K pathway component, and CD9, a tetraspanin family member.

Method: The expression of PIK3CD and CD9 were examined on 76 FL tumor tissues and 15 normal tissues with Immunohistochemistry. Chi-square test, Cox proportional hazards model, and Kaplan-Meier estimates were used to analyze the relationships of CD9 and PIK3CD expression and major clinicopathological features.

Result: PIK3CD expression was significantly higher, whereas CD9 expression was significantly lower in the 76 FL specimens than normal tissues. Concomitantly, low CD9 or high PIK3CD expression is associated with high degrees of Ann Arbor stages. In agreement with this, PIK3CD is an unfavorable and CD9 is a favorable factor for progression-free survival (PFS). Interestingly, PIK3CD expression is negatively correlated with CD9 expression, and the PIK3CD-high/CD9-low was significantly associated with short PFS when the 2 factors were combined together. Lastly, CD9 expression was significant higher in patients with bone marrow infiltration (BMI) than those without BMI.

Conclusion: Both CD9 and PIK3CD are prognostic markers of FL. The negative correlation between CD9 and PIK3CD expression suggests that there may be crosstalks of the 2 proteins in FL.

Wednesday, October 12, 2016 3:24 PM|Atif A. Ahmed, Malak Abedalthagafi, Ahmed E. Anwar, Marilyn M. Bui|Journal of Cancer (RSS 2.0)|Labels: AKT, mTOR, childhood cancer, sarcoma

Background: Ewing's sarcoma tumor is an aggressive malignancy of bone and soft tissue in children and young adults. Despite advances in modern therapy, metastasis occurs and results in high mortality. Intracellular molecules Yap, Akt, mTOR, and Erk are signaling pathway members that regulate the proliferation of tumor cells.

Objective and Methods: We studied the immunohistochemical expression of these proteins in 36 tumor samples from adult and pediatric patients with Ewing's sarcoma tumors. Patients' age, sex, tumor site, tumor size, clinical stage and survival (overall and disease-free survival) were collected. Tissue microarrays slides were stained with antibodies against Yap, Akt, mTOR, and Erk proteins.

Results: Tumors exhibited variable expression of Yap, Akt, mTOR, and Erk (from negative, low to high), with high levels of expression present in 31%, 53%, 77% and 0% respectively. Immunohistochemical expression of Akt was associated with worse overall and disease-free survival (p<0.05). The other biomarkers did not demonstrate any difference in survival between low versus high expression.

Conclusion: Although Yap, Akt, mTOR, and Erk protein are all expressed in Ewing's sarcoma by immunohistochemistry, only Akt expression is associated with worse prognosis. Larger studies are needed to verify these results and plan targeted therapy, particularly against Akt.

Wednesday, October 12, 2016 3:24 PM|Leroy Shervington, Harshada Patil, Amal Shervington|Journal of Cancer (RSS 2.0)|Labels: AKT, HSP, brain cancer

Cancer inducible molecular chaperone HSP90 is of great importance as an anticancer target. Proteomic analysis showed that inhibiting HSP90 by the geldanamycin derivative, 17-AAG elevated the expression of the co-chaperone Hsp70. In this study we used HSP90 selective inhibitor 17-AAG and HSP70/90 dual inhibitor, VER155008 (VER) in U87-MG glioma cells. miRNAs microarray technology was used to evaluate the efficacy of these inhibitory drugs compared with temozolomide (TMZ), used as a standard treatment for glioma. Microarrays data identified 154 differentially expressed miRNAs using stringent or unstringent parameters. 16 miRNAs were overlapped between treatments, 13 upregulated and one downregulated miRNA were overlapped between TMZ and VER. The miRNA target prediction software was used for these overlapped miRNAs and identified 6 of the 13 upregulated miRNAs target methyltransferase genes. The IC50, together with Akt and HSP70 and 90 protein level data favour VER and TMZ to 17-AAG, however due to the selectivity of VER to cancer cells as a potent antichaperon, it may be more favourable to the standard TMZ.

Wednesday, October 12, 2016 3:24 PM|Ruolin Zhao, Meijuan Chen, Zequn Jiang, Fengming Zhao, Beili Xi, Xu Zhang, Haian Fu, Kunfu Zhou|Journal of Cancer (RSS 2.0)|Labels: AKT, MapK, mTOR, lung cancer

Platycodin-D (PD) is an effective triterpene saponin extracted from the root of Platycodon grandiflorum which has been used clinically to treat pulmonary diseases in traditional Chinese medicine. Recently, it has been reported that PD has anti-tumor effects in various cancer models through the induction of apoptosis. However, whether PD induces autophagy in both cell lines and its molecular mechanisms have not been elucidated. Here, our present study confirmed that PD induced autophagy in both NCI-H460 and A549 cells via up-regulating the expression levels of Atg-3, Atg-7 and Beclin-1. Meanwhile, PD contributed to the up-regulation of LC3-II at both protein and mRNA levels. Further detection of the PI3K/Akt/mTOR signaling pathway compared to LY294002 (PI3K kinase inhibitor), RAP (mTOR kinase inhibitor) and insulin (an activator of PI3K/Akt/mTOR signaling pathway) showed that PD induced autophagy through inhibiting the pathway at p-Akt (Ser473), p-p70S6K (Thr389) and p-4EBP1 (Thr37/46) in both cell lines. Moreover, the examination of MAPK signaling pathway showed that PD treatment increased the phosphorylation of JNK and p38 MAPK, while decreased the phosphorylation of Erk1/2 in both cell lines. Additionally, the effects assessed with a panel of pharmacologic inhibitors, including U0126 (Erk1/2 kinase inhibitor), SP600125 (JNK kinase inhibitor) and SB203580 (p38 MAPK kinase inhibitor) suggested that the activation of JNK and p38 MAPK participated in PD-induced autophagy. Taken together, these findings suggested that PD induced autophagy in NCI-H460 and A549 cells through inhibiting PI3K/Akt/mTOR signaling pathway and activating JNK and p38 MAPK signaling pathways. Therefore, PD may be an alternative compound for NSCLC therapy.

Wednesday, October 12, 2016 3:24 PM|Wenzhi Li, Fengfu Guo, Meng Gu, Guangjian Wang, Xiangfei He, Juan Zhou, Yubing Peng, Zhong Wang, Xiang Wang|Journal of Cancer (RSS 2.0)|Labels: AKT, mTOR, prostate cancer, clinical trial

Background: Golgi phosphoprotein 3 (GOLPH3) is a metastasis-associated gene, however its role in cell proliferation of prostate cancer (PCa) has not yet been elucidated.

Methods: The level of expression of GOLPH3 and other genes was examined by quantitative real-time PCR (QPCR) and western blot analysis. Furthermore, we performed a comprehensive analysis of the expression of GOLPH3 in PCa using a tissue microarray (TMA) and correlated our findings with pathological parameters of PCa. RNA interference (RNAi) was used to silence the expression of GOLPH3 in PC-3 cells and to measure the effects on proliferation and cell cycle using the CCK-8 assay and flow cytometry. Western blots were also employed to assess AKT-mTOR and cell cycle-related proteins.

Results: We showed that the expression of GOLPH3 was located at the trans-Golgi membranes in PCa cells. We found that GOLPH3 was expressed in all PCa cells and was significantly higher in two androgen-independent cell lines, DU145 and PC-3. TMA immunohistochemistry showed that GOLPH3 was positive in 64% of cancer tissue samples compared with 20% in normal and 30% in benign samples (P<0.05). In vitro, silencing GOLPH3 expression inhibited cell proliferation and arrested the cell cycle at the G2/M phase. Silencing GOLPH3 also activated P21 expression but suppressed the expression of CDK1/2 and cyclinB1 protein together with the phosphorylation of AKT and mTOR.

Conclusions: The expression of the GOLPH3 protein was significantly elevated in PCa. GOLPH3 can promote cell proliferation by enhancing the activity of AKT-mTOR signaling. Altogether, these findings suggest that GOLPH3 play important roles in proliferation and cell cycle regulation in PCa and might serve as promising biomarkers for PCa progression as well as potential therapeutic targets.

Wednesday, October 12, 2016 3:24 PM|Yue Xi, Hang Gao, Michael U. Callaghan, Andrew M. Fribley, Danielle M. Garshott, Zhi-Xiang Xu, Qinghua Zeng, Yu-Lin Li|Journal of Cancer (RSS 2.0)|Labels: AKT, NFKb, HNN

Naturally occurring diarylheptanoid curcumin (CUR), a principal component of the Asian spice turmeric, has been shown to have anti-cancer effects in many tumor types. However, a detailed mechanism regarding CUR induced tumor cell killing remain to be comprehensively explored. Using two head neck squamous cell carcinoma (HNSCC) cell lines FaDu (hypopharyngeal) and Cal27 (tongue), we demonstrated a novel mechanism by which CUR levies the cytotoxic effect. We found that CUR induced upregulation of pro-apoptotic Bik, down-regulation of survival signaling by AKT and NF-κB prior to the induction of the caspase-cascade reduction of cell proliferation, are primary mechanisms of CUR-induced cell death, thus providing insights into the anti-tumor activity of CUR in HNSCC cells.

Wednesday, October 12, 2016 3:24 PM|Kalliopi Domvri, Paul Zarogoulidis, Kaid Darwiche, Robert F. Browning, Qiang Li, J. Francis Turner, Ioannis Kioumis, Dionysios Spyratos, Konstantinos Porpodis, Antonis Papaiwannou, Theodora Tsiouda, Lutz Freitag, Konstantinos Zarogoulidis|Journal of Cancer|Labels: AKT, lung cancer, biomarker diagnostic

Lung cancer first line treatment has been directed from the non-specific cytotoxic doublet chemotherapy to the molecular targeted. The major limitation of the targeted therapies still remains the small number of patients positive to gene mutations. Furthermore, the differentiation between second line and maintenance therapy has not been fully clarified and differs in the clinical practice between cancer centers. The authors present a segregation between maintenance treatment and second line and present a possible definition for the term “maintenance” treatment. In addition, cancer cell evolution induces mutations and therefore either targeted therapies or non-specific chemotherapy drugs in many patients become ineffective. In the present work pathways such as epidermal growth factor, anaplastic lymphoma kinase, met proto-oncogene and PI3K are extensively presented and correlated with current chemotherapy treatment. Future, perspectives for targeted treatment are presented based on the current publications and ongoing clinical trials.

Wednesday, October 12, 2016 3:24 PM|Gabriel Tinoco, Sean Warsch, Stefan Glück, Kiran Avancha, Alberto J. Montero|Journal of Cancer|Labels: AKT, EGFR, HDAC, IGFR, HSP, mTOR, PARP, breast cancer, clinical trial

For many years, the medical treatment of breast cancer was reliant solely on cytotoxic chemotherapy. However, over the past twenty years, treatment has evolved to a more target-directed approach. We now employ tailored therapy based on the presence or absence of receptors for estrogen, progesterone, and human epidermal growth factor 2 (HER2). We expect this trend to continue, as agents that use novel approaches to target HER2, as well as targeting different portions of the HER signaling pathway, are in various stages of development. Notably, pertuzumab, a humanized monoclonal antibody that binds to a different domain of the extracellular portion of the HER2 receptor than trastuzumab, was recently approved for use, as was lapatinib, a small-molecule tyrosine kinase inhibitor. Patients with triple negative breast cancer, particularly those with the BRCA mutation, have more limited treatment options and carry a worse prognosis than those who are hormone receptor positive. However, recent data has shown that PARP inhibitors may have significant anti-tumor effect in those with this subtype of breast cancer. Novel agents that inhibit mTOR, PI3K, the insulin-like growth factor, heat shock protein 90, and histone deacetylase have shown promise in phase I-III trials and offer exciting new possibilities for the treatment of this often fatal disease. As we are presented with an ever increasing number of treatment options, the timing and combinations of therapeutic agents used becomes ever more complex in the age of personalized care, but we are hopeful that ultimately this will lead to improved patient outcomes.

Wednesday, October 12, 2016 3:24 PM|Yansong Bian, Jiawei Han, Vishnu Kannabiran, Suresh Mohan, Hui Cheng, Jay Friedman, Luo Zhang, Carter VanWaes, Zhong Chen|International Journal of Biological Sciences|Labels: AKT, mTOR, NFKb, HNN

The serine-threonine kinase CK2 exhibits genomic alterations and aberrant overexpression in human head and neck squamous cell carcinomas (HNSCC). Here, we investigated the effects of CK2 inhibitor CX-4945 in human HNSCC cell lines and xenograft models. The IC50's of CX-4945 for 9 UM-SCC cell lines measured by MTT assay ranged from 3.4-11.9 μM. CX-4945 induced cell cycle arrest and cell death measured by DNA flow cytometry, and inhibited prosurvival mediators phospho-AKT and p-S6 in UM-SCC1 and UM-SCC46 cells. CX-4945 decreased NF-κB and Bcl-XL reporter gene activities in both cell lines, but upregulated proapoptotic TP53 and p21 reporter activities, and induced phospho-ERK, AP-1, and IL-8 activity in UM-SCC1 cells. CX-4945 exhibited modest anti-tumor activity in UM-SCC1 xenografts. Tumor immunostaining revealed significant inhibition of PI3K-Akt-mTOR pathway and increased apoptosis marker TUNEL, but also induced p-ERK, c-JUN, JUNB, FOSL1 and proliferation (Ki67) markers, as a possible resistance mechanism. To overcome the drug resistance, we tested MEK inhibitor PD-0325901 (PD-901), which inhibited ERK-AP-1 activation alone and in combination with CX-4945. PD-901 alone displayed significant anti-tumor effects in vivo, and the combination of PD-901 and CX-4945 slightly enhanced anti-tumor activity when compared with PD-901 alone. Immunostaining of tumor specimens after treatment revealed inhibition of p-AKT S129 and p-AKT T308 by CX-4945, and inhibition of p-ERK T202/204 and AP-1 family member FOSL-1 by PD-901. Our study reveals a drug resistance mechanism mediated by the MEK-ERK-AP-1 pathway in HNSCC. MEK inhibitor PD-0325901 is active in HNSCC resistant to CX-4945, meriting further clinical investigation.

Wednesday, October 12, 2016 3:24 PM|Cun Wang, Haojie Jin, Ning Wang, Shaohua Fan, Yanyan Wang, Yurong Zhang, Lin Wei, Xuemei Tao, Dishui Gu, Fangyu Zhao, Jingyuan Fang, Ming Yao, Wenxin Qin|Theranostics|Labels: AKT, breast cancer

Chemoresistance in breast cancer has been of great interest in past studies. However, the development of rational therapeutic strategies targeting chemoresistant cells is still a challenge in clinical oncology. By integrating data from global differences of gene expression and phospho-receptor tyrosine kinases between sensitive parental cells (MCF-7) and doxorubicin-resistant cells (MCF-7/ADR), we identified Axl as a potential target for chemoresistance and metastasis in multidrug resistant breast cancer cells. We analyzed Axl expression in 57 breast cancer cell lines and detected a dramatic increase in its expression level in mesenchymal breast cancer cell lines. Axl silencing suppressed invasive and metastatic potentials of chemoresistant breast cancer cells as well as increased elimination of cancer cells when combined with doxorubicin. Furthermore, in preclinical assays, an Axl inhibitor R428 showed increased cell death upon doxorubicin treatment. Additionally, using phospho-kinase array based proteomic analysis, we identified that Akt/GSK-3β/β-catenin cascade was responsible for Axl-induced cell invasion. Nuclear translocation of β-catenin then induced transcriptional upregulation of ZEB1, which in turn regulated DNA damage repair and doxorubicin-resistance in breast cancer cells. Most importantly, Axl was correlated with its downstream targets in tumor samples and was associated with poor prognosis in breast cancer patients. These results demonstrate that Gas6/Axl axis confers aggressiveness in breast cancer and may represent a therapeutic target for chemoresistance and metastasis.

Wednesday, October 12, 2016 3:24 PM|Yurong Zhang, Xuemei Tao, Guangzhi Jin, Haojie Jin, Ning Wang, Fangyuan Hu, Qin Luo, Huiqun Shu, Fangyu Zhao, Ming Yao, Jingyuan Fang, Wenming Cong, Wenxin Qin, Cun Wang|Theranostics|Labels: AKT, HSP, liver cancer

Heat shock protein 27 (Hsp27) is an ATP-independent molecular chaperone and confers survival advantages and resistance to cancer cells under stress conditions. The effects and molecular mechanisms of Hsp27 in HCC invasion and metastasis are still unclear. In this study, hepatocellular carcinoma (HCC) tissue array (n = 167) was used to investigate the expression and prognostic relevance of Hsp27 in HCC patients. HCC patients with high expression of Hsp27 exhibited poor prognosis. Overexpression of Hsp27 led to the forced invasion of HCC cells, whereas silencing Hsp27 attenuated invasion and metastasis of HCC cells in vitro and in vivo. We revealed that Hsp27 activated Akt signaling, which in turn promoted MMP2 and ITGA7 expression and HCC metastasis. We further observed that targeting Hsp27 using OGX-427 obviously suppressed HCC metastasis in two metastatic models. These findings indicate that Hsp27 is a useful predictive factor for prognosis of HCC and it facilitates HCC metastasis through Akt signaling. Targeting Hsp27 with OGX-427 may represent an attractive therapeutic option for suppressing HCC metastasis.

Wednesday, October 12, 2016 3:24 PM|Qianxiang Zhou, Yali Chen, Xi Chen, Wennan Zhao, Yuxu Zhong, Ran Wang, Meihua Jin, Yuling Qiu, Dexin Kong|International Journal of Biological Sciences|Labels: AKT, Bcr-Abl, leukemia, clinical trial

Chronic myelogenous leukemia (CML) is a malignant hematological disorder mainly caused by the Bcr-Abl tyrosine kinase. While Bcr-Abl inhibitors including Imatinib showed antitumor efficacy on many CML patients, resistance was frequently reported in recent years. Therefore, novel drugs for CML are still expected. ZSTK474 is a specific phosphatidylinositol 3-kinase (PI3K) inhibitor that we identified. In the present study, the efficacy of ZSTK474, alone or in combination with Imatinib, on K562 CML cells as well as on its multidrug resistance counterpart K562/A02 cells, was investigated. ZSTK474 inhibited the cell proliferation with an IC50 of 4.69 μM for K562 and 7.57 μM for K562/A02 cells, respectively. Treatment by ZSTK474 resulted in cell cycle arrest in G1 phase, which might be associated with upregulation of p27, and downregulation of cyclin D1. ZSTK474 also inhibited phosphorylation of Akt and GSK-3β, which might be involved in the effect on the above cell cycle-related proteins. Moreover, combination of ZSTK474 and Imatinib indicated synergistic effect on both cell lines. In conclusion, ZSTK474 exhibited antileukemia activity alone, and showed synergistic effect when combined with Imatinib, on CML K562 cells as well as the multidrug resistant ones, providing a potential therapeutic approach for CML patients.

Wednesday, October 12, 2016 3:24 PM|Mengtao Ma, Miao He, Qian Jiang, Yuanyuan Yan, Shu Guan, Jing Zhang, Zhaojin Yu, Qiuchen Chen, Mingli Sun, Weifan Yao, Haishan Zhao, Feng Jin, Minjie Wei|International Journal of Biological Sciences|Labels: AKT, breast cancer

Tumor metastasis is a complex and multistep process and its exact molecular mechanisms remain unclear. We attempted to find novel microRNAs (miRNAs) contributing to the migration and invasion of breast cancer cells. In this study, we found that the expression of miR-487a was higher in MDA-MB-231breast cancer cells with high metastasis ability than MCF-7 breast cancer cells with low metastasis ability and the treatment with transforming growth factor β1 (TGF-β1) significantly increased the expression of miR-487a in MCF-7 and MDA-MB-231 breast cancer cells. Subsequently, we found that the transfection of miR-487a inhibitor significantly decreased the expression of vimentin, a mesenchymal marker, while increased the expression of E-cadherin, an epithelial marker, in both MCF-7 cells and MDA-MB-231 cells. Also, the inactivation of miR-487a inhibited the migration and invasion of breast cancer cells. Furthermore, our findings demonstrated that miR-487a directly targeted the MAGI2 involved in the stability of PTEN. The down-regulation of miR-487a increased the expression of p-PTEN and PTEN, and reduced the expression of p-AKT in both cell lines. In addition, the results showed that NF-kappaB (p65) significantly increased the miR-487a promoter activity and expression, and TGF-β1 induced the increased miR-487a promoter activity via p65 in MCF-7 cells and MDA-MB-231 cells. Moreover, we further confirmed the expression of miR-487a was positively correlated with the lymph nodes metastasis and negatively correlated with the expression of MAGI2 in human breast cancer tissues. Overall, our results suggested that miR-487a could promote the TGF-β1-induced EMT, the migration and invasion of breast cancer cells by directly targeting MAGI2.

Wednesday, October 12, 2016 3:24 PM|Chia-Ing Jan, Ming-Hsui Tsai, Chang-Fang Chiu, Yi-Ping Huang, Chia Jen Liu, Nai Wen Chang|International Journal of Biological Sciences|Labels: AKT, mTOR

One anticancer strategy suggests targeting mitochondrial metabolism to trigger cell death through slowing down energy production from the Warburg effect. Fenofibrate is a clinical lipid-lowering agent and an effective anticancer drug. In the present study, we demonstrate that fenofibrate provided novel mechanisms for delaying oral tumor development via the reprogramming of metabolic processes. Fenofibrate induced cytotoxicity by decreasing oxygen consumption rate (OCR) that was accompanied with increasing extracellular acidification rate (ECAR) and reducing ATP content. Moreover, fenofibrate caused changes in the protein expressions of hexokinase II (HK II), pyruvate kinase, pyruvate dehydrogenase, and voltage-dependent anion channel (VDAC), which are associated with the Warburg effect. In addition, fenofibrate reprogrammed the metabolic pathway by interrupting the binding of HK II to VDAC. In an oral cancer mouse model, fenofibrate exhibited both preventive and therapeutic efficacy on oral tumorigenesis. Fenofibrate administration suppressed the incidence rate of tongue lesions, reduced the tumor sizes, decreased the tumor multiplicity, and decreased the immunoreactivities of VDAC and mTOR. The molecular mechanisms involved in fenofibrate's ability to delay tumor development included the down-regulation of mTOR activity via TSC1/2-dependent signaling through activation of AMPK and inactivation of Akt, or via a TSC1/2-independent pathway through direct suppression of raptor. Our findings provide a molecular rationale whereby fenofibrate exerts anticancer and additional beneficial effects for the treatment of oral cancer patients.

Wednesday, October 12, 2016 3:24 PM|Jingrong Xian, Huiyuan Shao, Xianchun Chen, Shuaishuai Zhang, Jing Quan, Qin Zou, Hongjun Jin, Ling Zhang|International Journal of Biological Sciences|Labels: AKT, MapK, RAS, leukemia

Acute myeloid leukemia (AML) with mutated nucleophosmin (NPM1) has been defined as a unique subgroup in the new classification of myeloid neoplasm, and the AML patients with mutated NPM1 frequently present extramedullary infiltration, but how NPM1 mutants regulate this process remains elusive. In this study, we found that overexpression of type A NPM1 gene mutation (NPM1-mA) enhanced the adhesive, migratory and invasive potential in THP-1 AML cells lacking mutated NPM1. NPM1-mA had up-regulated expression and gelatinolytic matrix metalloprotease-2 (MMP-2)/MMP-9 activity, as assessed by real-time PCR, western blotting and gelatin zymography. Following immunoprecipitation analysis to identify the interaction of NPM1-mA with K-Ras, we focused on the effect of NPM1-mA overexpression on the Ras/Mitogen-activated protein kinase (MAPK) signaling axis and showed that NPM1-mA increased the MEK and ERK phosphorylation levels, as evaluated by western blotting. Notably, a specific inhibitor of the ERK/MAPK pathway (PD98059), but not p38/MAPK, JNK/MAPK or PI3-K/AKT inhibitors, markedly decreased the cell invasion numbers in a transwell assay. Further experiments demonstrated that blocking the ERK/MAPK pathway by PD98059 resulted in reduced MMP-2/9 protein levels and MMP-9 activity. Additionally, NPM1-mA overexpression had down-regulated gene expression and protein production of tissue inhibitor of MMP-2 (TIMP-2) in THP-1 cells. Furthermore, evaluation of gene expression data from The Cancer Genome Atlas (TCGA) dataset revealed that MMP-2 was overexpressed in AML patient samples with NPM1 mutated and high MMP-2 expression associated with leukemic skin infiltration. Taken together, our results reveal that NPM1 mutations contribute to the invasive potential of AML cells through MMPs up-regulation via Ras/ERK MAPK signaling pathway activation and offer novel insights into the potential role of NPM1 mutations in leukemogenesis.

Wednesday, October 12, 2016 3:22 PM|Wei-Tian Wei, Hui Chen, Zhao-Hong Wang, Zhong-Lin Ni, Hai-Bin Liu, Hong-Fei Tong, Hong-Chun Guo, Dian-Lei Liu, Sheng-Zhang Lin|International Journal of Biological Sciences|Labels: AKT, mTOR, NFKb, pancreatic cancer

Evodiamine has therapeutic potential against cancers. This study was designed to investigate whether combination therapy with gemcitabine and evodiamine enhanced antitumor efficacy in pancreatic cancer. In vitro application of the combination therapy triggered significantly higher frequency of pancreatic cancer cells apoptosis, inhibited the activities of PI3K, Akt, PKA, mTOR and PTEN, and decreased the activation of NF-κB and expression of NF-κB-regulated products. In vivo application of the combination therapy induced significant enhancement of tumor cell apoptosis, reductions in tumor volume, and inhibited activation of mTOR and PTEN. In conclusion, evodiamine can augment the therapeutic effect of gemcitabine in pancreatic cancer through direct or indirect negative regulation of the PI3K/Akt pathway.

Wednesday, October 12, 2016 11:36 AM|Derek Lowe|MIT Biotech Group - Essential Biotech RSS Feed|Labels: AKT, IGFR, HSP, skin cancer

Today’s second “bad behavior” story comes courtesy of Retraction Watch and Leonard Schneider’s For Better Science. Schneider has been tracking some problems with papers from Min-Jean Yin, who was working at Pfizer’s La Jolla site. Five papers that came out of her work there are now being retracted – duplicate images in the gels were picked up by folks who commented on PubPeer, and an internal Pfizer investigation confirmed the duplications. It’s taken a few months, but it appears that not only is Pfizer requesting that the papers all be retracted, but that Yin is no longer an employee of the company.

Here are the five papers, and as you can see, they stretch across several different projects:

What isn’t clear is how much of this fraud affected internal work at Pfizer. You’d have to think that Yin was generating proprietary data for these various projects, and eventually they were cleared for publication for one reason or another. The way it works in the drug industry, projects are often some way back in the rear-view mirror by the time that happens, and you generally aren’t able to go back and generate new data just for the paper (or at least not much). So you really have to wonder if some of Pfizer’s own drug discovery efforts got messed up by some of this fakery, or if these were just images stuck on to make the manuscripts look more complete. Neither possibility is good, of course. . .

Monday, October 10, 2016 7:17 AM|MICHAEL, J. V., WURTZEL, J. G. T., GOLDFINGER, L. E.|Anticancer Research current issue|Labels: AKT, MapK, mTOR, RAS

The goal of this study was to develop combinatorial application of two drugs currently either in active use as anticancer agents (rapamycin) or in clinical trials (OTX008) as a novel strategy to inhibit Harvey RAS (HRAS)-driven tumor progression. HRAS anchored to the plasma membrane shuttles from the lipid ordered (Lo) domain to the lipid ordered/lipid disordered border upon activation, and retention of HRAS at these sites requires galectin-1. We recently showed that genetically enforced Lo sequestration of HRAS inhibited mitogen-activated protein kinase (MAPK) signaling, but not phoshatidylinositol 3-kinase (PI3K) activation. Here we show that inhibition of galectin-1 with OTX008 sequestered HRAS in the Lo domain, blocked HRAS-mediated MAPK signaling, and attenuated HRAS-driven tumor progression in mice. HRAS-driven tumor growth was also attenuated by treatment with mammalian target of rapamycin (mTOR) inhibitor rapamycin, and this effect was further enhanced in tumors driven by Lo-sequestered HRAS. These drugs also revealed bidirectional cross-talk in HRAS pathways. Moreover, dual pathway inhibition with OTX008 and rapamycin resulted in nearly complete ablation of HRAS-driven tumor growth. These findings indicate that membrane microdomain sequestration of HRAS with galectin-1 inhibition, coupled with mTOR inhibition, may support a novel therapeutic approach to treat HRAS-mutant cancer.

Saturday, October 8, 2016 8:00 PM|Hui Huang|International Journal of Molecular Sciences|Labels: AKT, MapK, mTOR
Cancer is one of the leading causes of death worldwide and a major global health problem. In recent decades, the rates of both mortality and morbidity of cancer have rapidly increased for a variety of reasons. Despite treatment options, there are serious side effects associated with chemotherapy drugs and multiple forms of drug resistance that significantly reduce their effects. There is an accumulating amount of evidence on the pharmacological activities of baicalein (e.g., anti-inflammatory, antioxidant, antiviral, and antitumor effects). Furthermore, there has been great progress in elucidating the target mechanisms and signaling pathways of baicalein’s anti-cancer potential. The anti-tumor functions of baicalein are mainly due to its capacities to inhibit complexes of cyclins to regulate the cell cycle, to scavenge oxidative radicals, to attenuate mitogen activated protein kinase (MAPK), protein kinase B (Akt) or mammalian target of rapamycin (mTOR) activities, to induce apoptosis by activating caspase-9/-3 and to inhibit tumorinvasion and metastasis by reducing the expression of matrix metalloproteinase-2/-9 (MMP-2/-9). In this review, we focused on the relevant biological mechanisms of baicalein involved in inhibiting various cancers, such as bladder cancer, breast cancer, and ovarian cancer. Moreover, we also summarized the specific mechanisms by which baicalein inhibited the growth of various tumors in vivo. Taken together, baicalein may be developed as a potential, novel anticancer drug to treat tumors.
Wednesday, October 5, 2016 12:05 AM|Kim, A. L., Back, J. H., Zhu, Y., Tang, X., Yardley, N. P., Kim, K. J., Athar, M., Bickers, D. R.|Cancer Prevention Research recent issues|Labels: AKT, Hh/SMO

Patients with basal cell nevus syndrome (BCNS), also known as Gorlin syndrome, develop numerous basal cell carcinomas (BCC) due to germline mutations in the tumor suppressor PTCH1 and aberrant activation of Hedgehog (Hh) signaling. Therapies targeted at components of the Hh pathway, including the smoothened (SMO) inhibitor vismodegib, can ablate these tumors clinically, but tumors recur upon drug discontinuation. Using SKH1-Ptch1+/– as a model that closely mimics the spontaneous and accelerated growth pattern of BCCs in patients with BCNS, we show that AKT1, a serine/threonine protein kinase, is intrinsically activated in keratinocytes derived from the skin of newborn Ptch1+/– mice in the absence of carcinogenic stimuli. Introducing Akt1 haplodeficiency in Ptch1+/– mice (Akt1+/– Ptch1+/–) significantly abrogated BCC growth. Similarly, pharmacological inhibition of AKT with perifosine, an alkyl phospholipid AKT inhibitor, diminished the growth of spontaneous and UV-induced BCCs. Our data demonstrate an obligatory role for AKT1 in BCC growth, and targeting AKT may help reduce BCC tumor burden in BCNS patients. Cancer Prev Res; 9(10); 794–802. ©2016 AACR.

Tuesday, October 4, 2016 3:42 PM|Ceroi, A., Masson, D., Roggy, A., Roumier, C., Chague, C., Gauthier, T., Philippe, L., Lamarthee, B., Angelot-Delettre, F., Bonnefoy, F., Perruche, S., Biichle, S., Preudhomme, C., Macintyre, E., Lagrost, L., Garnache-Ottou, F., Saas, P.|BLOOD First Edition Papers|Labels: AKT, ALL

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is an aggressive hematological malignancy with a poor prognosis that derives from plasmacytoid dendritic cells (PDC). No consensus for optimal treatment modalities is available today and the full characterization of this leukemia is still emerging. We identified here a BPDCN-specific transcriptomic profile when compared to those of acute myeloid leukemia and T-acute lymphoblastic leukemia, as well as the transcriptomic signature of primary PDC. This BPDCN gene signature identified a dysregulation of genes involved in cholesterol homeostasis, some of them being liver X receptor (LXR) target genes. LXR agonist treatment of primary BPDCN cells and BPDCN cell lines restored LXR target gene expression and increased cholesterol efflux via the upregulation of ATP Binding Cassette (ABC) transporters, ABCA1 and ABCG1. LXR agonist treatment was responsible for limiting BPDCN cell proliferation and inducing intrinsic apoptotic cell death. LXR activation in BPDCN cells was shown to interfere with three signaling pathways associated with leukemic cell survival, namely: NF-B activation, as well as Akt and STAT5 phosphorylation in response to the BPDCN growth/survival factor IL-3. These effects were increased by the stimulation of cholesterol efflux through a lipid acceptor, the apolipoprotein A1. In vivo experiments using a mouse model of BPDCN cell xenograft revealed a decrease of leukemic cell infiltration and BPDCN-induced cytopenia associated with an increased survival after LXR agonist treatment. This demonstrates that cholesterol homeostasis is modified in BPDCN and can be normalized by treatment with LXR agonists which can be proposed as a new therapeutic approach.

Monday, October 3, 2016 12:05 AM|Smith, M. C., Mader, M. M., Cook, J. A., Iversen, P., Ajamie, R., Perkins, E., Bloem, L., Yip, Y. Y., Barda, D. A., Waid, P. P., Zeckner, D. J., Young, D. A., Sanchez-Felix, M., Donoho, G. P., Wacheck, V.|Molecular Cancer Therapeutics current issue|Labels: AKT, mTOR, clinical trial

The PI3K/AKT/mTOR pathway is among the most frequently altered pathways in cancer cell growth and survival. LY3023414 is a complex fused imidazoquinolinone with high solubility across a wide pH range designed to inhibit class I PI3K isoforms and mTOR kinase. Here, we describe the in vitro and in vivo activity of LY3023414. LY3023414 was highly soluble at pH 2–7. In biochemical testing against approximately 266 kinases, LY3023414 potently and selectively inhibited class I PI3K isoforms, mTORC1/2, and DNA-PK at low nanomolar concentrations. In vitro, inhibition of PI3K/AKT/mTOR signaling by LY3023414 caused G1 cell-cycle arrest and resulted in broad antiproliferative activity in cancer cell panel screens. In vivo, LY3023414 demonstrated high bioavailability and dose-dependent dephosphorylation of PI3K/AKT/mTOR pathway downstream substrates such as AKT, S6K, S6RP, and 4E-BP1 for 4 to 6 hours, reflecting the drug's half-life of 2 hours. Of note, equivalent total daily doses of LY3023414 given either once daily or twice daily inhibited tumor growth to similar extents in multiple xenograft models, indicating that intermittent target inhibition is sufficient for antitumor activity. In combination with standard-of-care drugs, LY3023414 demonstrated additive antitumor activity. The novel, orally bioavailable PI3K/mTOR inhibitor LY3023414 is highly soluble and exhibits potent in vivo efficacy via intermittent target inhibition. It is currently being evaluated in phase I and II trials for the treatment of human malignancies. Mol Cancer Ther; 15(10); 2344–56. ©2016 AACR.

Monday, October 3, 2016 12:05 AM|Qin, Y., Roszik, J., Chattopadhyay, C., Hashimoto, Y., Liu, C., Cooper, Z. A., Wargo, J. A., Hwu, P., Ekmekcioglu, S., Grimm, E. A.|Molecular Cancer Therapeutics current issue|Labels: AKT, BRAF, melanoma, skin cancer

Melanoma is molecularly and structurally heterogeneous, with some tumor cells existing under hypoxic conditions. Our cell growth assays showed that under controlled hypoxic conditions, BRAF(V600E) melanoma cells rapidly became resistant to vemurafenib. By employing both a three-dimensional (3D) spheroid model and a two-dimensional (2D) hypoxic culture system to model hypoxia in vivo, we identified upregulation of HGF/MET signaling as a major mechanism associated with vemurafenib resistance as compared with 2D standard tissue culture in ambient air. We further confirmed that the upregulation of HGF/MET signaling was evident in drug-resistant melanoma patient tissues and mouse xenografts. Pharmacologic inhibition of the c-Met/Akt pathway restored the sensitivity of melanoma spheroids or 2D hypoxic cultures to vemurafenib. Mol Cancer Ther; 15(10); 2442–54. ©2016 AACR.

Monday, October 3, 2016 12:05 AM|Le, X., Antony, R., Razavi, P., Treacy, D. J., Luo, F., Ghandi, M., Castel, P., Scaltriti, M., Baselga, J., Garraway, L. A.|Cancer Discovery recent issues|Labels: AKT, breast cancer

PIK3CA (which encodes the PI3K alpha isoform) is the most frequently mutated oncogene in breast cancer. Small-molecule PI3K inhibitors have shown promise in clinical trials; however, intrinsic and acquired resistance limits their utility. We used a systematic gain-of-function approach to identify genes whose upregulation confers resistance to the PI3K inhibitor BYL719 in breast cancer cells. Among the validated resistance genes, Proviral Insertion site in Murine leukemia virus (PIM) kinases conferred resistance by maintaining downstream PI3K effector activation in an AKT-independent manner. Concurrent pharmacologic inhibition of PIM and PI3K overcame this resistance mechanism. We also observed increased PIM expression and activity in a subset of breast cancer biopsies with clinical resistance to PI3K inhibitors. PIM1 overexpression was mutually exclusive with PIK3CA mutation in treatment-naïve breast cancers, suggesting downstream functional redundancy. Together, these results offer new insights into resistance to PI3K inhibitors and support clinical studies of combined PIM/PI3K inhibition in a subset of PIK3CA-mutant cancers.

Significance: PIM kinase overexpression confers resistance to small-molecule PI3K inhibitors. Combined inhibition of PIM and PI3K may therefore be warranted in a subset of breast cancers. Cancer Discov; 6(10); 1134–47. ©2016 AACR.

This article is highlighted in the In This Issue feature, p. 1069

Monday, October 3, 2016 12:05 AM|Okada, T., Lee, A. Y., Qin, L.-X., Agaram, N., Mimae, T., Shen, Y., O'Connor, R., Lopez-Lago, M. A., Craig, A., Miller, M. L., Agius, P., Molinelli, E., Socci, N. D., Crago, A. M., Shima, F., Sander, C., Singer, S.|Cancer Discovery current issue|Labels: AKT, INT, mTOR, sarcoma

Myxofibrosarcoma is a common mesenchymal malignancy with complex genomics and heterogeneous clinical outcomes. Through gene-expression profiling of 64 primary high-grade myxofibrosarcomas, we defined an expression signature associated with clinical outcome. The gene most significantly associated with disease-specific death and distant metastasis was ITGA10 (integrin-α10). Functional studies revealed that myxofibrosarcoma cells strongly depended on integrin-α10, whereas normal mesenchymal cells did not. Integrin-α10 transmitted its tumor-specific signal via TRIO and RICTOR, two oncoproteins that are frequently co-overexpressed through gene amplification on chromosome 5p. TRIO and RICTOR activated RAC/PAK and AKT/mTOR to promote sarcoma cell survival. Inhibition of these proteins with EHop-016 (RAC inhibitor) and INK128 (mTOR inhibitor) had antitumor effects in tumor-derived cell lines and mouse xenografts, and combining the drugs enhanced the effects. Our results demonstrate the importance of integrin-α10/TRIO/RICTOR signaling for driving myxofibrosarcoma progression and provide the basis for promising targeted treatment strategies for patients with high-risk disease.

Significance: Identifying the molecular pathogenesis for myxofibrosarcoma progression has proven challenging given the highly complex genomic alterations in this tumor type. We found that integrin-α10 promotes tumor cell survival through activation of TRIO–RAC–RICTOR–mTOR signaling, and that inhibitors of RAC and mTOR have antitumor effects in vivo, thus identifying a potential treatment strategy for patients with high-risk myxofibrosarcoma. Cancer Discov; 6(10); 1148–65. ©2016 AACR.

This article is highlighted in the In This Issue feature, p. 1069

Monday, October 3, 2016 12:05 AM|Okkenhaug, K., Graupera, M., Vanhaesebroeck, B.|Cancer Discovery recent issues|Labels: AKT

The PI3K pathway is hyperactivated in most cancers, yet the capacity of PI3K inhibitors to induce tumor cell death is limited. The efficacy of PI3K inhibition can also derive from interference with the cancer cells' ability to respond to stromal signals, as illustrated by the approved PI3K inhibitor idelalisib in B-cell malignancies. Inhibition of the leukocyte-enriched PI3K or PI3K may unleash antitumor T-cell responses by inhibiting regulatory T cells and immune-suppressive myeloid cells. Moreover, tumor angiogenesis may be targeted by PI3K inhibitors to enhance cancer therapy. Future work should therefore also explore the effects of PI3K inhibitors on the tumor stroma, in addition to their cancer cell–intrinsic impact.

Significance: The PI3K pathway extends beyond the direct regulation of cancer cell proliferation and survival. In B-cell malignancies, targeting PI3K purges the tumor cells from their protective microenvironment. Moreover, we propose that PI3K isoform–selective inhibitors may be exploited in the context of cancer immunotherapy and by targeting angiogenesis to improve drug and immune cell delivery. Cancer Discov; 6(10); 1090–105. ©2016 AACR.

Monday, October 3, 2016 12:05 AM|Haesen, D., Abbasi Asbagh, L., Derua, R., Hubert, A., Schrauwen, S., Hoorne, Y., Amant, F., Waelkens, E., Sablina, A., Janssens, V.|Cancer Research recent issues|Labels: AKT, uterine cancer
Somatic missense mutations in the Ser/Thr protein phosphatase 2A (PP2A) Aα scaffold subunit gene PPP2R1A are among the few genomic alterations that occur frequently in serous endometrial carcinoma (EC) and carcinosarcoma, two clinically aggressive subtypes of uterine cancer with few therapeutic options. Previous studies reported that cancer-associated Aα mutants exhibit defects in binding to other PP2A subunits and contribute to cancer development by a mechanism of haploinsufficiency. Here we report on the functional significance of the most recurrent PPP2R1A mutations in human EC, which cluster in Aα HEAT repeats 5 and 7. Beyond predicted loss-of-function effects on the formation of a subset of PP2A holoenzymes, we discovered that Aα mutants behave in a dominant-negative manner due to gain-of-function interactions with the PP2A inhibitor TIPRL1. Dominant-negative Aα mutants retain binding to specific subunits of the B56/B′ family and form substrate trapping complexes with impaired phosphatase activity via increased recruitment of TIPRL1. Accordingly, overexpression of the Aα mutants in EC cells harboring wild-type PPP2R1A increased anchorage-independent growth and tumor formation, and triggered hyperphosphorylation of oncogenic PP2A-B56/B′ substrates in the GSK3β, Akt, and mTOR/p70S6K signaling pathways. TIPRL1 silencing restored GSK3β phosphorylation and rescued the EC cell growth advantage. Our results reveal how PPP2R1A mutations affect PP2A function and oncogenic signaling, illuminating the genetic basis for serous EC development and its potential control by rationally targeted therapies. Cancer Res; 76(19); 5719–31. ©2016 AACR.
Thursday, September 29, 2016 8:35 AM|Findlay, J. M., Bradley, K. M., Wang, L. M., Franklin, J. M., Teoh, E. J., Gleeson, F. V., Maynard, N. D., Gillies, R. S., Middleton, M. R.|JNM Ahead of Print|Labels: AKT, esophageal cancer

INTRODUCTION: Only a minority of esophageal cancers demonstrates a pathological tumor response (pTR) to neoadjuvant chemotherapy (NAC). 18F-fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-CT) is often used for restaging after NAC and to assess response. Increasingly, it is used during therapy to identify unresponsive tumors and predict pTR , using avidity of the primary tumor alone. However, definitions of such metabolic tumor response (mTR) vary. We aimed to comprehensively re-evaluate metabolic response assessment using accepted parameters, as well as novel concepts of metabolic nodal stage (mN) and nodal response (mNR). PATIENTS AND METHODS: This was a single-center retrospective UK cohort study. All patients with esophageal cancer staged before NAC with PET-CT and after with CT or PET-CT and undergoing resection from 2006-2014 were identified. pTR was defined as Mandard tumor regression grade 1-3; imaging parameters included metrics of tumor avidity (standardized uptake value [SUV]max/mean/peak), composites of avidity and volume (including metabolic tumor volume), nodal SUVmax, and our new concepts of mN stage and mNR. RESULTS: Eighty-two (27.2%) of 301 patients demonstrated pTR. No pre-NAC PET parameters predicted pTR. In 220 patients re-staged by PET-CT, The optimal tumor SUVmax threshold was a 77.8% reduction. This was as sensitive as the current PET Response Criteria in Solid Tumors (PERCIST) 30% reduction, but more specific with a higher negative predictive value (p<0.001). SUVmax and length independently predicted pTR, and composite avidity/spatial metrics outperformed avidity alone. Whilst both mTR and mNR were associated with pTR, in 82 patients with FDG-avid nodes before NAC we observed mNR in 10 (12.2%) not demonstrating mTR. CONCLUSION: Current definitions of metabolic response are suboptimal and too simplistic. Composite avidity/volume measures improve prediction. mNR may further improve response assessment, by specifically assessing metastatic tumor sub-populations, likely responsible for disease relapse, and should be urgently assessed when considering aborting therapy on the basis of mTR alone.

Tuesday, September 27, 2016 9:44 AM|Zhou, J., Alfraidi, A., Zhang, S., Santiago-O'Farrill, J., Yerramreddy, V., Alsaadid, A., Ahmed, A. A., Yang, H., Liu, J., Mao, W., Takemori, H., Wang, Y., Vankayalapati, H., Lu, Z., Bast, R. C.|Clinical Cancer Research Online First Articles|Labels: AKT, ovarian cancer

Purpose:SIK2 is a centrosome kinase required for mitotic spindle formation and a potential target for ovarian cancer therapy. Here we examine the effects of a novel small molecule SIK2 inhibitor, ARN-3236, on sensitivity to paclitaxel in ovarian cancer. Experimental Design:SIK2 expression was determined in ovarian cancer tissue samples and cell lines. ARN-3236 was tested for its efficiency to inhibit growth and enhance paclitaxel sensitivity in cultures and xenografts of ovarian cancer cell lines. SIK2 siRNA and ARN-3236 were compared for their ability to produce nuclear-centrosome dissociation, inhibit centrosome splitting, block mitotic progression, induce tetraploidy, trigger apoptotic cell death and reduce AKT/survivin signaling. Results:SIK2 is overexpressed in approximately 30% of high grade serous ovarian cancers. ARN-3236 inhibited growth of 10 ovarian cancer cell lines at an IC50 of 0.8 to 2.6 μM, where the IC50 of ARN-3236 was inversely correlated with endogenous SIK2 expression (Pearson's r = -0.642, P = 0.03). ARN-3236 enhanced sensitivity to paclitaxel in 8 of 10 cell lines, as well as in SKOv3ip (P = 0.028) and OVCAR8 xenografts. In at least three cell lines a synergistic interaction was observed. ARN-3236 uncoupled the centrosome from the nucleus in interphase, blocked centrosome separation in mitosis, caused prometaphase arrest and induced apoptotic cell death and tetraploidy. ARN-3236 also inhibited AKT phosphorylation and attenuated survivin expression. Conclusions:ARN-3236 is the first orally available inhibitor of SIK2 to be evaluated against ovarian cancer in preclinical models and shows promise in inhibiting ovarian cancer growth and enhancing paclitaxel chemosensitivity.

Monday, September 26, 2016 2:21 PM|Wu, D.-W., Wu, T.-C., Chen, C.-Y., Lee, H.|Clinical Cancer Research Online First Articles|Labels: AKT, EGFR, lung cancer, biomarker diagnostic

Purpose: EGFR mutation as a biomarker has documented that EGFR-mutant patients will derive clinical benefit from tyrosine kinase inhibitor (TKI) treatment. Unfortunately, most patients show TKI resistance and tumor recurrence after therapy. Therefore, we expected that an adjuvant biomarker other than EGFR mutation is needed for predicting TKI resistance.

Experimental Design: Molecular manipulations were performed to verify whether TKI resistance mediated by p21-activated kinase (PAK1) could be through increasing Mcl-1 protein stability via the PI3K/AKT/C/EBP-β/miR-145 cascade. Xenograft mouse models were used to confirm the mechanistic action of PAK1 on TKI resistance. Forty-six tumor tissues from patients with lung adenocarcinoma who received TKI therapy were collected to evaluate PAK1 and E-cadherin mRNA expressions by real-time PCR. The association of PAK1 and E-cadherin mRNA expressions with tumor response to TKI treatment and outcomes was evaluated.

Results: We demonstrate that PAK1 confers TKI resistance in EGFR-mutant cells as well as in EGFR–wild-type cells. Mechanistically, the positive feedback loop of PAK1/PI3K/AKT/C/EBP-β/miR-145 cascades persistently activates the PI3K/AKT signaling pathway to protect Mcl-1 degradation by Fbw7, which results, in turn, in TKI resistance and cell invasion via epithelial-to-mesenchymal transition due to a decrease in E-cadherin expression. The mechanism underlying the cell model is further confirmed in xenograft tumors. Among patients, high-PAK1 or low–E-cadherin tumors more commonly exhibited an unfavorable response to TKI and poorer outcome compared with low-PAK1 or low–E-cadherin tumors.

Conclusions: The combination of TKI with AKT inhibitor might confer TKI sensitivity and in turn improve outcomes in patients with lung adenocarcinoma who harbored high PAK1 mRNA–expressing tumors. Clin Cancer Res; 1–13. ©2016 AACR.

Monday, September 26, 2016 1:51 PM|Chiang, M. Y., Wang, Q., Gormley, A. C., Stein, S. J., Xu, L., Shestova, O., Aster, J. C., Pear, W. S.|BLOOD First Edition Papers|Labels: AKT, Notch, ALL, leukemia

Activating NOTCH1 mutations are frequent in human T-cell acute lymphoblastic leukemia (T-ALL) and Notch inhibitors (gamma-secretase inhibitors or GSI) have produced responses in patients with relapsed, refractory disease. However, sustained responses, while reported, are uncommon, suggesting other pathways can substitute for Notch in T-ALL. To address this possibility, we first generated KrasG12D transgenic mice with T-cell specific expression of the pan-Notch inhibitor, DNMAML. These mice developed leukemia, but instead of accessing alternative oncogenic pathways, the tumor cells acquired Notch1 mutations and subsequently deleted DNMAML, reinforcing the notion that activated Notch1 is particularly transforming within the context of T-cell progenitors. We next took a candidate approach to identify oncogenic pathways downstream of Notch, focusing on Myc and Akt, which are Notch targets in T-cell progenitors. KrasG12D mice transduced with Myc developed T-ALLs that were GSI-insensitive and lacked Notch1 mutations. In contrast, KrasG12D mice transduced with myr-AKT developed GSI-sensitive T-ALLs that acquired Notch1 mutations. Thus, Myc can substitute for Notch1 in leukemogenesis, whereas Akt cannot. These findings in primary tumors extend recent work using human T-ALL cell lines and xenografts and suggest that the Notch/Myc signaling axis is of predominant importance in understanding both the selective pressure for Notch mutations in T-ALL and response and resistance of T-ALL to Notch pathway inhibitors.

Saturday, September 24, 2016 10:50 AM|Wei Wang; Di-long Fang; Yong-jun Jin|JournalTOCs API - Biochemical and Biophysical Research Communications (50 articles)|Labels: AKT, mTOR, TNF, CRC

mTOR inhibition sensitizes ONC201-induced anti-colorectal cancer cell activity
Zhe-zhu Jin Wei Wang; Di-long Fang; Yong-jun Jin
Biochemical and Biophysical Research Communications, Vol. 478, No. 4 (2016) pp. 1515 - 1520
Publication date: 30 September 2016 Source:Biochemical and Biophysical Research Communications, Volume 478, Issue 4 Author(s): Zhe-zhu Jin, Wei Wang, Di-long Fang, Yong-jun Jin We here tested the anti-colorectal cancer (CRC) activity by a first-in-class small molecule TRAIL inducer ONC201. The potential effect of mTOR on ONC201's actions was also examined. ONC201 induced moderate cytotoxicity against CRC cell lines (HT-29, HCT-116 and DLD-1) and primary human CRC cells. Significantly, AZD-8055, a mTOR kinase inhibitor, sensitized ONC201-induced cytotoxicity in CRC cells. Meanwhile, ONC201-induced TRAIL/death receptor-5 (DR-5) expression, caspase-8 activation and CRC cell apoptosis were also potentiated with AZD-8055 co-treatment. Reversely, TRAIL sequestering antibody RIK-2 or the caspase-8 specific inhibitor z-IETD-fmk attenuated AZD-8055 plus ONC201-induced CRC cell death. Further, mTOR kinase-dead mutation (Asp-2338-Ala) or shRNA knockdown significantly sensitized ONC201's activity in CRC cells, leading to profound cell death and apoptosis. On the other hand, expression of a constitutively-active S6K1 (T389E) attenuated ONC201-induced CRC cell apoptosis. For the mechanism study, we showed that ONC201 blocked Akt, but only slightly inhibited mTOR in CRC cells. Co-treatment with AZD-8055 also concurrently blocked mTOR activation. These results suggest that mTOR could be a primary resistance factor of ONC201 in CRC cells.

Friday, September 23, 2016 12:47 PM|Berns, K., Sonnenblick, A., Gennissen, A., Brohee, S., Hijmans, E. M., Evers, B., Fumagalli, D., Desmedt, C., Loibl, S., Denkert, C., Neven, P., Guo, W., Zhang, F., Knijnenburg, T. A., Bosse, T., van der Heijden, M. S., Hindriksen, S., Nijkamp, W., Wessels, L. F. A., Joensuu, H., Mills, G. B., Beijersbergen, R. L., Sotiriou, C., Bernards, R.|Clinical Cancer Research Online First Articles|Labels: AKT, EGFR, mTOR, biomarker diagnostic

Purpose: Despite the substantial progress in the development of targeted anticancer drugs, treatment failure due to primary or acquired resistance is still a major hurdle in the effective treatment of most advanced human cancers. Understanding these resistance mechanisms will be instrumental to improve personalized cancer treatment.

Experimental Design: Genome-wide loss-of-function genetic screens were performed to identify genes implicated in resistance to HER2/PI3K/mTOR targeting agents in HER2+ breast cancer cell lines. Expression and adjuvant trastuzumab response data from the HER2+ breast cancer trials FinHer and Responsify were used to validate our findings in patient series.

Results: We find that reduced ARID1A expression confers resistance to several drugs that inhibit the HER2/PI3K/mTOR signaling cascade at different levels. We demonstrate that ARID1A loss activates annexin A1 (ANXA1) expression, which is required for drug resistance through its activation of AKT. We find that the AKT inhibitor MK2206 restores sensitivity of ARID1A knockdown breast cancer cells to both the mTOR kinase inhibitor AZD8055 and trastuzumab. Consistent with these in vitro data, we find in two independent HER2+ breast cancer patient series that high ANXA1 expression is associated with resistance to adjuvant trastuzumab–based therapy.

Conclusions: Our findings provide a rationale for why tumors accumulate ARID1A mutations and identify high ANXA1 expression as a predictive biomarker for trastuzumab-based treatment. Our findings also suggest strategies to treat breast cancers with elevated ANXA1 expression. Clin Cancer Res; 1–11. ©2016 AACR.

Friday, September 23, 2016 12:47 PM|Au-Yeung, G., Lang, F., Azar, W. J., Mitchell, C., Jarman, K. E., Lackovic, K., Aziz, D., Cullinane, C., Pearson, R. B., Mileshkin, L., Rischin, D., Karst, A. M., Drapkin, R., Etemadmoghadam, D., Bowtell, D. D. L.|Clinical Cancer Research Online First Articles|Labels: AKT, CDK, ovarian cancer

Purpose: Cyclin E1 (CCNE1) amplification is associated with primary treatment resistance and poor outcome in high grade serous ovarian cancer (HGSC). Here, we explore approaches to target CCNE1 amplified cancers and potential strategies to overcome resistance to targeted agents. Experiment Design: To examine dependency on CDK2 in CCNE1 amplified HGSC, we utilised siRNA and conditional shRNA gene suppression, and chemical inhibition using dinaciclib, a small molecule CDK2 inhibitor. High throughput compound screening was used to identify selective synergistic drug combinations, as well as combinations that may overcome drug resistance. An observed relationship between CCNE1 and the AKT pathway was further explored in genomic data from primary tumors, and functional studies in fallopian tube secretory cells. Results: We validate CDK2 as a therapeutic target by demonstrating selective sensitivity to gene suppression. However, we found that dinaciclib did not trigger amplicon-dependent sensitivity in a panel of HGSC cell lines. A high throughput compound screen identified synergistic combinations in CCNE1 amplified HGSC, including dinaciclib and AKT inhibitors. Analysis of genomic data from TCGA demonstrated co-amplification of CCNE1 and AKT2. Over-expression of Cyclin E1 and AKT isoforms, in addition to mutant TP53, imparted malignant characteristics in untransformed fallopian tube secretory cells, the dominant site of origin of HGSC. Conclusions: These findings suggest a specific dependency of CCNE1 amplified tumors for AKT activity, and point to a novel combination of dinaciclib and AKT inhibitors that may selectively target patients with CCNE1 amplified HGSC.

Thursday, September 15, 2016 12:00 PM|Vallois, D., Dobay, M. P. D., Morin, R. D., Lemonnier, F., Missiaglia, E., Juilland, M., Iwaszkiewicz, J., Fataccioli, V., Bisig, B., Roberti, A., Grewal, J., Bruneau, J., Fabiani, B., Martin, A., Bonnet, C., Michielin, O., Jais, J.-P., Figeac, M., Bernard, O. A., Delorenzi, M., Haioun, C., Tournilhac, O., Thome, M., Gascoyne, R. D., Gaulard, P., de Leval, L.|Blood LYMPHOID NEOPLASIA|Labels: AKT, lymphoma

Angioimmunoblastic T-cell lymphoma (AITL) and other lymphomas derived from follicular T-helper cells (TFH) represent a large proportion of peripheral T-cell lymphomas (PTCLs) with poorly understood pathogenesis and unfavorable treatment results. We investigated a series of 85 patients with AITL (n = 72) or other TFH-derived PTCL (n = 13) by targeted deep sequencing of a gene panel enriched in T-cell receptor (TCR) signaling elements. RHOA mutations were identified in 51 of 85 cases (60%) consisting of the highly recurrent dominant negative G17V variant in most cases and a novel K18N in 3 cases, the latter showing activating properties in in vitro assays. Moreover, half of the patients carried virtually mutually exclusive mutations in other TCR-related genes, most frequently in PLCG1 (14.1%), CD28 (9.4%, exclusively in AITL), PI3K elements (7%), CTNNB1 (6%), and GTF2I (6%). Using in vitro assays in transfected cells, we demonstrated that 9 of 10 PLCG1 and 3 of 3 CARD11 variants induced MALT1 protease activity and increased transcription from NFAT or NF-B response element reporters, respectively. Collectively, the vast majority of variants in TCR-related genes could be classified as gain-of-function. Accordingly, the samples with mutations in TCR-related genes other than RHOA had transcriptomic profiles enriched in signatures reflecting higher T-cell activation. Although no correlation with presenting clinical features nor significant impact on survival was observed, the presence of TCR-related mutations correlated with early disease progression. Thus, targeting of TCR-related events may hold promise for the treatment of TFH-derived lymphomas.

Thursday, September 15, 2016 8:45 AM|Facompre, N. D., Harmeyer, K. M., Sole, X., Kabraji, S., Belden, Z., Sahu, V., Whelan, K., Tanaka, K., Weinstein, G. S., Montone, K. T., Roesch, A., Gimotty, P. A., Herlyn, M., Rustgi, A. K., Nakagawa, H., Ramaswamy, S., Basu, D.|Cancer Research recent issues|Labels: AKT
The degree of heterogeneity among cancer stem cells (CSC) remains ill-defined and may hinder effective anti-CSC therapy. Evaluation of oral cancers for such heterogeneity identified two compartments within the CSC pool. One compartment was detected using a reporter for expression of the H3K4me3 demethylase JARID1B to isolate a JARID1Bhigh fraction of cells with stem cell–like function. JARID1Bhigh cells expressed oral CSC markers including CD44 and ALDH1 and showed increased PI3K pathway activation. They were distinguished from a fraction in a G0-like cell-cycle state characterized by low reactive oxygen species and suppressed PI3K/AKT signaling. G0-like cells lacked conventional CSC markers but were primed to acquire stem cell–like function by upregulating JARID1B, which directly mediated transition to a state expressing known oral CSC markers. The transition was regulated by PI3K signals acting upstream of JARID1B expression, resulting in PI3K inhibition depleting JARID1Bhigh cells but expanding the G0-like subset. These findings define a novel developmental relationship between two cell phenotypes that may jointly contribute to CSC maintenance. Expansion of the G0-like subset during targeted depletion of JARID1Bhigh cells implicates it as a candidate therapeutic target within the oral CSC pool. Cancer Res; 76(18); 5538–49. ©2016 AACR.
Wednesday, September 7, 2016 9:03 AM|Mato, A. R., Nabhan, C., Barr, P. M., Ujjani, C. S., Hill, B. T., Lamanna, N., Skarbnik, A. P., Howlett, C., Pu, J. J., Sehgal, A. R., Strelec, L. E., Vandegrift, A., Fitzpatrick, D. M., Zent, C. S., Feldman, T., Goy, A., Claxton, D. F., Bachow, S. H., Kaur, G., Svoboda, J., Nasta, S. D., Porter, D., Landsburg, D. J., Schuster, S. J., Cheson, B. D., Kiselev, P., Evens, A. M.|BLOOD First Edition Papers|Labels: AKT, Bcr-Abl, P53, leukemia

B Cell receptor (BCR) kinase inhibitor (KI) therapy represents a paradigm shift in Chronic Lymphocytic Leukemia (CLL) management, but data on practice patterns after KI discontinuation and optimal sequencing are limited. We conducted a multicenter, retrospective, comprehensive analysis on 178 CLL patients (ibrutinib=143; idelalisib=35) who discontinued KI therapy. We examined responses, toxicity, post-KI therapies, and overall survival (OS). Patients had a median of 3 prior therapies (range 0-11); del17p (34%), p53 mutation (27%), del11q (33%), and complex karyotype (29%). Overall response rate (ORR) to first KI was 62% (complete response (CR) 14%). The most common reasons for KI discontinuation were toxicity (51%), CLL progression (29%), and Richter's transformation (RT) (8%). Median progression free survival (PFS) and OS from KI initiation were 10.5 and 29 months, respectively. Notably, initial KI choice did not impact PFS or OS, however, RT portended significantly inferior OS (P=0.0007). 114 patients received subsequent salvage therapy following KI discontinuation with an ORR to subsequent KI at 50% and a median PFS of 11.9 months. Median PFS in KI intolerant patients treated with an alternate KI was not reached (NR) versus 7 months for patients with CLL progression. In summary, these data demonstrate that toxicity was the most common reason for KI discontinuation, and that patients who discontinue KI due to toxicity can respond to an alternate KI, and these responses may be durable.

Tuesday, September 6, 2016 5:00 PM|Cancer|Cancer via MedWorm.com|Comments|Labels: AKT, endometrial cancer, clinical trial
CONCLUSIONSThe antitumor activity noted with the use of a dose of 40 mg of apitolisib daily was limited by tolerability, especially in diabetic patients. Patients with PI3K pathway mutations may have derived enhanced benefit from apitolisib. Cancer 2016. © 2016 American Cancer Society. (Source: Cancer)
Tuesday, September 6, 2016 12:39 PM|Gupta, S., Li, J., Kemeny, G., Bitting, R. L., Beaver, J., Somarelli, J., Ware, K. E., Gregory, S., Armstrong, A. J.|Clinical Cancer Research Online First Articles|Labels: AKT, prostate cancer, biomarker diagnostic

Purpose: Beyond enumeration, circulating tumor cells (CTCs) can provide genetic information from metastatic cancer that may facilitate a greater understanding of tumor biology and enable a precision medicine approach. Experimental design: CTCs and paired leukocytes from men with metastatic castration-resistant prostate cancer (mCRPC) were isolated from blood through red cell lysis, CD45 depletion, and flow sorting based on EpCAM/CD45 expression. We next performed whole genomic copy number analysis of CTCs and matched patient leukocytes (germline) using array-based comparative genomic hybridization (aCGH) from 16 men with mCRPC, including longitudinal and sequential CTCs aCGH analyses in the context of enzalutamide therapy. Results: All patients had mCRPC and primary or acquired resistance to abiraterone acetate or enzalutamide. We compiled copy gains and losses, with a particular focus on those genes highly implicated in mCRPC progression and previously validated as being aberrant in metastatic tissue samples and genomic studies of reference mCRPC datasets. Genomic gains in >25% of CTCs were observed in AR, FOXA1, ABL1, MET, ERG, CDK12, BRD4, and ZFHX3, while common genomic losses involved PTEN, ZFHX3, PDE4DIP, RAF1, and GATA2. Analysis of aCGH in a sample with sequential enzalutamide resistant visceral progression showed acquired loss of AR amplification concurrent with gain of MYCN, consistent with evolution toward a neuroendocrine-like, AR-independent clone. Conclusions: Genomic analysis of pooled CTCs in men with mCRPC suggests a reproducible, but highly complex molecular profile that includes common aberrations in AR, ERG, c-MET, and PI3K signaling during mCRPC progression, which may be useful for predictive biomarker development.

Tuesday, September 6, 2016 12:30 AM|Yusuke Takagi, Kazuyuki Shimada, Satoko Shimada, Akihiko Sakamoto, Tomoki Naoe, Shigeo Nakamura, Fumihiko Hayakawa, Akihiro Tomita, Hitoshi Kiyoi|Cancer Science|Labels: AKT, lymphoma, biomarker diagnostic
Although the clinical outcomes of diffuse large B-cell lymphoma (DLBCL) have improved in the immunochemotherapy era, approximately one-third of patients develop intractable disease. To improve clinical outcomes for these patients, it is important to identify those with poor prognosis prior to initial treatment in order to select optimal therapies. Here, we investigated the clinical and biological significance of SPIB, an Ets family transcription factor linked to lymphomagenesis, in DLBCL. We classified 134 DLBCL patients into SPIB negative (n = 108) or SPIB positive (n = 26) groups by immunohistochemical staining. SPIB positive patients had a significantly worse treatment response and poor prognosis compared with SPIB negative patients. Multivariate analysis for patient survival indicated that SPIB expression was an independent poor prognostic factor for both progression free survival (PFS) and overall survival (OS) (PFS, hazard ratio [HR] 2.65, 95% confidence interval [CI] 1.31–5.33, P = 0.006; OS, HR 3.56, 95% CI 1.43–8.91, P = 0.007). Subsequent analyses of the roles of SPIB expression in DLBCL pathogenesis revealed that SPIB expression in lymphoma cells resulted in resistance to the BH3-mimetic ABT-263 and contributed to apoptosis resistance via the PI3K-AKT pathway. The inhibition of AKT phosphorylation re-sensitized SPIB expressing lymphoma cells to ABT-263-induced cell death. Together, our data indicate that SPIB expression is a clinically novel poor prognostic factor in DLBCL that contributes to treatment resistance, at least in part, through an anti-apoptotic mechanism. We investigated the clinical and biological role of SPIB in diffuse large B-cell lymphoma. In this analysis, we evaluated SPIB expression in DLBCL by routine immunohistochemical staining and demonstrated that SPIB expression was a novel poor prognostic factor and potential biomarker for DLBCL that is, at least in part, involved in apoptosis resistance via the PI3K-AKT pathway.
Monday, September 5, 2016 7:55 AM|Masaru Tanaka|JournalTOCs API - Biochimica et Biophysica Acta (BBA) - Molecular Cell Research (50 articles)|Labels: AKT, P-gp, CRC

Decellularized matrices as in vitro models of extracellular matrix in tumor tissues at different malignant levels: Mechanism of 5-fluorouracil resistance in colorectal tumor cells
Takashi Hoshiba Masaru Tanaka
Biochimica et Biophysica Acta (BBA) - Molecular Cell Research, Vol. 1863, No. 11 (2016) pp. 2749 - 2757
Publication date: November 2016 Source:Biochimica et Biophysica Acta (BBA) - Molecular Cell Research, Volume 1863, Issue 11 Author(s): Takashi Hoshiba, Masaru Tanaka Chemoresistance is a major barrier for tumor chemotherapy. It is well-known that chemoresistance increases with tumor progression. Chemoresistance is altered by both genetic mutations and the alteration of extracellular microenvironment. Particularly, the extracellular matrix (ECM) is remodeled during tumor progression. Therefore, ECM remodeling is expected to cause the acquisition of chemoresistance in highly malignant tumor tissue. Here, we prepared cultured cell-derived decellularized matrices that mimic native ECM in tumor tissues at different stages of malignancy, and 5-fluorouracil (5-FU) resistance was compared among these matrices. 5-FU resistance of colorectal tumor cells increased on the matrices derived from highly malignant tumor HT-29 cells, although the resistance did not increase on the matrices derived from low malignant tumor SW480 cells and normal CCD-841-CoN cells. The resistance on HT-29 cell-derived matrices increased through the activation of Akt and the upregulation of ABCB1 and ABCC1 without cell growth promotion, suggesting that ECM remodeling plays important roles in the acquisition of chemoresistance during tumor progression. It is expected that our decellularized matrices, or “staged tumorigenesis-mimicking matrices”, will become preferred cell culture substrates for in vitro analysis of comprehensive ECM roles in chemoresistance and the screening and pharmacokinetic analysis of anti-cancer drugs.

Friday, September 2, 2016 8:35 AM|Ogitani, Y., Aida, T., Hagihara, K., Yamaguchi, J., Ishii, C., Harada, N., Soma, M., Okamoto, H., Oitate, M., Arakawa, S., Hirai, T., Atsumi, R., Nakada, T., Hayakawa, I., Abe, Y., Agatsuma, T.|Clinical Cancer Research Online First Articles|Labels: AKT, EGFR, biomarker diagnostic

Purpose: An anti-HER2 antibody–drug conjugate with a novel topoisomerase I inhibitor, DS-8201a, was generated as a new antitumor drug candidate, and its preclinical pharmacologic profile was assessed.

Experimental Design: In vitro and in vivo pharmacologic activities of DS-8201a were evaluated and compared with T-DM1 in several HER2-positive cell lines and patient-derived xenograft (PDX) models. The mechanism of action for the efficacy was also evaluated. Pharmacokinetics in cynomolgus monkeys and the safety profiles in rats and cynomolgus monkeys were assessed.

Results: DS-8201a exhibited a HER2 expression-dependent cell growth–inhibitory activity and induced tumor regression with a single dosing at more than 1 mg/kg in a HER2-positive gastric cancer NCI-N87 model. Binding activity to HER2 and ADCC activity of DS-8201a were comparable with unconjugated anti-HER2 antibody. DS-8201a also showed an inhibitory activity to Akt phosphorylation. DS-8201a induced phosphorylation of Chk1 and Histone H2A.X, the markers of DNA damage. Pharmacokinetics and safety profiles of DS-8201a were favorable and the highest non-severely toxic dose was 30 mg/kg in cynomolgus monkeys, supporting DS-8201a as being well tolerated in humans. DS-8201a was effective in a T-DM1–insensitive PDX model with high HER2 expression. DS-8201a, but not T-DM1, demonstrated antitumor efficacy against several breast cancer PDX models with low HER2 expression.

Conclusions: DS-8201a exhibited a potent antitumor activity in a broad selection of HER2-positive models and favorable pharmacokinetics and safety profiles. The results demonstrate that DS-8201a will be a valuable therapy with a great potential to respond to T-DM1–insensitive HER2-positive cancers and low HER2–expressing cancers. Clin Cancer Res; 1–12. ©2016 AACR.

Thursday, September 1, 2016 12:05 AM|Lu, H., Wang, T., Li, J., Fedele, C., Liu, Q., Zhang, J., Jiang, Z., Jain, D., Iozzo, R. V., Violette, S. M., Weinreb, P. H., Davis, R. J., Gioeli, D., FitzGerald, T. J., Altieri, D. C., Languino, L. R.|Cancer Research recent issues|Labels: AKT, Bcl-2, INT, prostate cancer
Androgen receptor signaling fuels prostate cancer and is a major therapeutic target. However, mechanisms of resistance to therapeutic androgen ablation are not well understood. Here, using a prostate cancer mouse model, Ptenpc−/−, carrying a prostate epithelial-specific Pten deletion, we show that the αvβ6 integrin is required for tumor growth in vivo of castrated as well as of noncastrated mice. We describe a novel signaling pathway that couples the αvβ6 integrin cell surface receptor to androgen receptor via activation of JNK1 and causes increased nuclear localization and activity of androgen receptor. This downstream kinase activation by αvβ6 is specific for JNK1, with no involvement of p38 or ERK kinase. In addition, differential phosphorylation of Akt is not observed under these conditions, nor is cell morphology affected by αvβ6 expression. This pathway, which is specific for αvβ6, because it is not regulated by a different αv-containing integrin, αvβ3, promotes upregulation of survivin, which in turn supports anchorage-independent growth of αvβ6-expressing cells. Consistently, both αvβ6 and survivin are significantly increased in prostatic adenocarcinoma, but are not detected in normal prostatic epithelium. Neither XIAP nor Bcl-2 is affected by αvβ6 expression. In conclusion, we show that αvβ6 expression is required for prostate cancer progression, including castrate-resistant prostate cancer; mechanistically, by promoting activation of JNK1, the αvβ6 integrin causes androgen receptor–increased activity in the absence of androgen and consequent upregulation of survivin. These preclinical results pave the way for further clinical development of αvβ6 antagonists for prostate cancer therapy. Cancer Res; 76(17); 5163–74. ©2016 AACR.
Thursday, September 1, 2016 12:05 AM|Unknown Author|Cancer Discovery recent issues|Labels: AKT, breast cancer

SGK1 drives resistance to PI3Kα inhibitors in PI3KCA mutant breast cancer.

Thursday, September 1, 2016 12:05 AM|Zhang, H., Qi, J., Reyes, J. M., Li, L., Rao, P. K., Li, F., Lin, C. Y., Perry, J. A., Lawlor, M. A., Federation, A., De Raedt, T., Li, Y. Y., Liu, Y., Duarte, M. A., Zhang, Y., Herter-Sprie, G. S., Kikuchi, E., Carretero, J., Perou, C. M., Reibel, J. B., Paulk, J., Bronson, R. T., Watanabe, H., Brainson, C. F., Kim, C. F., Hammerman, P. S., Brown, M., Cichowski, K., Long, H., Bradner, J. E., Wong, K.-K.|Cancer Discovery recent issues|Labels: AKT, EGFR, lung cancer

As a master regulator of chromatin function, the lysine methyltransferase EZH2 orchestrates transcriptional silencing of developmental gene networks. Overexpression of EZH2 is commonly observed in human epithelial cancers, such as non–small cell lung carcinoma (NSCLC), yet definitive demonstration of malignant transformation by deregulated EZH2 remains elusive. Here, we demonstrate the causal role of EZH2 overexpression in NSCLC with new genetically engineered mouse models of lung adenocarcinoma. Deregulated EZH2 silences normal developmental pathways, leading to epigenetic transformation independent of canonical growth factor pathway activation. As such, tumors feature a transcriptional program distinct from KRAS- and EGFR-mutant mouse lung cancers, but shared with human lung adenocarcinomas exhibiting high EZH2 expression. To target EZH2-dependent cancers, we developed a potent open-source EZH2 inhibitor, JQEZ5, that promoted the regression of EZH2-driven tumors in vivo, confirming oncogenic addiction to EZH2 in established tumors and providing the rationale for epigenetic therapy in a subset of lung cancer.

Significance: EZH2 overexpression induces murine lung cancers that are similar to human NSCLC with high EZH2 expression and low levels of phosphorylated AKT and ERK, implicating biomarkers for EZH2 inhibitor sensitivity. Our EZH2 inhibitor, JQEZ5, promotes regression of these tumors, revealing a potential role for anti-EZH2 therapy in lung cancer. Cancer Discov; 6(9); 1006–21. ©2016 AACR.

See related commentary by Frankel et al., p. 949.

This article is highlighted in the In This Issue feature, p. 932

Thursday, September 1, 2016 12:05 AM|Meng, X., Tackmann, N. R., Liu, S., Yang, J., Dong, J., Wu, C., Cox, A. D., Zhang, Y.|Cancer Research recent issues|Labels: AKT, mTOR, P53, RAS
The ribosomal protein (RP)–MDM2 interaction is a p53 response pathway critical for preventing oncogenic c-MYC–induced tumorigenesis. To investigate whether the RP-MDM2-p53 pathway is a broad antioncogenic mechanism, we crossed mice bearing an MDM2C305F mutation, which disrupts RPL11 binding to MDM2, with mice expressing an oncogenic HrasG12V transgene. Interestingly, the MDM2C305F-mutant mice, which are hypersensitive to c-MYC–induced tumorigenesis, are not hypersensitive to oncogenic HrasG12V-induced tumorigenesis. Unlike c-MYC, which induces expression of RPL11, RAS overexpression leads to an increase in RPL23 mRNA and protein whereas RPL11 expression remains unchanged. The induction of RPL23 involves both MEK and PI3K signaling pathways and requires mTOR function. Increased expression of RPL23, which maintains binding to MDM2C305F mutant, correlates with increased p53 expression in MDM2C305F cells. Furthermore, RAS overexpression can induce p53 in the absence of p19ARF, and the induction can be abolished by downregulation of RPL23. Thus, although the RPL11–MDM2–p53 pathway coordinates with the p19ARF–MDM2–p53 pathway against oncogenic c-MYC–induced tumorigenesis, the RPL23–MDM2–p53 pathway coordinates with the p19ARF–MDM2–p53 pathway against oncogenic RAS-induced tumorigenesis. Cancer Res; 76(17); 5030–9. ©2016 AACR.
Thursday, August 25, 2016 8:29 AM|Reubi, J. C., Waser, B., Maecke, H. R., Rivier, J. E.|JNM Ahead of Print|Labels: AKT, prostate cancer

There is recent in vitro and in vivo evidence that somatostatin receptor sst2 antagonists are better tools to target neuroendocrine tumors (NET) than sst2 agonists. Indeed, antagonists bind to a greater number of sst2 sites than agonists. Whether sst2 antagonists could be used successfully to target non-NET tumors, expressing low sst2 density, is unknown. Here, we compare quantitatively 125I-JR11 sst2 antagonist binding in vitro with that of the sst2 agonist 125I-Tyr3-octreotide in large varieties of non-NET and NET. Methods: In vitro receptor autoradiography was performed with 125I-JR11 and 125I-Tyr3-octreotide in cancers from prostate, breast, colon, kidney, thyroid, and lymphoid tissues, as well as NETs as reference. Results: In general, 125I-JR11 binds to many more sst2 sites than 125I-Tyr3-octreotide. In 13 breast cancers, 8 have low binding (mean density: 844±168 dpm/mg tissue) with the agonist while 12 have a high binding (mean density: 4447±1128 dpm/mg tissue) with the antagonist. All 12 renal cell cancers (RCC) show a low binding of sst2 with the agonist (mean density: 348±49 dpm/mg tissue) while all cases have a very high sst2 binding with the antagonist (mean density: 3777±582 dpm/mg tissue). 1/5 medullary thyroid cancers are positive with the agonist, while 5/5 are positive with the antagonist. In 15 Non-Hodgkin lymphomas (NHL), many more sst2 sites are labelled with the antagonist than with the agonist. In 14 prostate cancers, none have sst2 binding with the agonist and only 4 have a weak binding with the antagonist. None of 17 colon cancers show sst2 sites with the agonist and only 3 cases are weakly positive with the antagonist. In the various tumor types, adjacent sst2-expressing tissues such as vessels, lymphocytes, nerves, mucosa or stroma were more strongly labelled with the antagonist than with the agonist. The reference NET cases, incubated with a smaller amount of tracer, were also found to have many more sst2 sites measured with the antagonist. Conclusion: All RCC, a majority of breast cancers, NHL and medullary thyroid cancers represent novel indications for the in vivo radiopeptide targeting of sst2 by sst2 antagonists, comparable to NET radiotargeting with sst2 agonists.

Friday, August 19, 2016 12:45 PM|Kelly, K. R., Mejia, A., Suhasini, A., Lin, A.-P., Kuhn, J. G., Karnad, A., Weitman, S., Aguiar, R. C. T.|Clinical Cancer Research Online First Articles|Labels: AKT, biomarker diagnostic, clinical trial, regulatory

Purpose:In this study, we aimed to validate our extensive pre-clinical data on phosphodiesterase 4 (PDE4) as actionable target in B-cell malignancies. Our specific objectives were to determine the safety, pharmacokinetics and pharmacodynamics (PI3K/AKT activity), as well as to capture any potential anti-tumor activity of the FDA-approved PDE4 inhibitor roflumilast in combination with prednisone in patients with advanced B cell malignancies. Experimental Design: Single center, exploratory phase Ib open-label, non-randomized study. Roflumilast (500 mcg PO) was given daily for 21 days with prednisone on days 8-14. Additional 21-day cycles were started if patients tolerated cycle 1 and had at least stable disease. Results:Ten patients, median age 65 years with an average of three prior therapies were enrolled. The median number of cycles administered was 4 [range: 1-13]. Treatment was generally well tolerated; the most common {greater than or equal to}Grade 2 treatment-related adverse events ({greater than or equal to}25%) were fatigue, anorexia and transient {greater than or equal to} grade 2 neutropenia (30%). Treatment with roflumilast as a single agent significantly suppressed PI3K activity in the 77% of patients evaluated; on average, patients with PI3K/AKT suppression stayed in trial for 156 days (49 - 315) vs. 91 days (28 - 139 days) for those without this biomarker response. Six of the nine evaluable patients (66%) had partial response or stable disease. The median number of days in trial was 105 days [range: 28-315]. Conclusions:Repurposing the PDE4 inhibitor roflumilast for treatment of B-cell malignancies is a safe, suppresses the activity of the oncogenic PI3K/AKT kinases, and may have clinical activity in this setting

Thursday, August 18, 2016 12:21 PM|Simone Buraschi et al.|Department of Pathology, Anatomy and Cell Biology Faculty Papers|Labels: AKT, MapK, bladder cancer, biomarker diagnostic

We have recently demonstrated a critical role for progranulin in bladder cancer. Progranulin contributes, as an autocrine growth factor, to the transformed phenotype by modulating Akt-and MAPK-driven motility, invasion and anchorage-independent growth. Progranulin also induces F-actin remodeling by interacting with the F-actin binding protein drebrin. In addition, progranulin is overexpressed in invasive bladder cancer compared to normal tissue controls, suggesting that progranulin might play a key role in driving the transition to the invasive phenotype of urothelial cancer. However, it is not established whether targeting progranulin could have therapeutic effects on bladder cancer. In this study, we stably depleted urothelial cancer cells of endogenous progranulin by shRNA approaches and determined that progranulin depletion severely inhibited the ability of tumorigenic urothelial cancer cells to migrate, invade and grow in anchorage-independency. We further demonstrate that progranulin expression is critical for tumor growth in vivo, in both xenograft and orthotopic tumor models. Notably, progranulin levels correlated with response to cisplatin treatment and were upregulated in bladder tumors. Our data indicate that progranulin may constitute a novel target for therapeutic intervention in bladder tumors. In addition, progranulin may serve as a novel biomarker for bladder cancer.

Monday, August 15, 2016 12:05 AM|Morrison Joly, M., Hicks, D. J., Jones, B., Sanchez, V., Estrada, M. V., Young, C., Williams, M., Rexer, B. N., Sarbassov, D. D., Muller, W. J., Brantley-Sieders, D., Cook, R. S.|Cancer Research recent issues|Labels: AKT, EGFR, breast cancer
HER2 overexpression drives Akt signaling and cell survival and HER2-enriched breast tumors have a poor outcome when Akt is upregulated. Akt is activated by phosphorylation at T308 via PI3K and S473 via mTORC2. The importance of PI3K-activated Akt signaling is well documented in HER2-amplified breast cancer models, but the significance of mTORC2-activated Akt signaling in this setting remains uncertain. We report here that the mTORC2 obligate cofactor Rictor is enriched in HER2-amplified samples, correlating with increased phosphorylation at S473 on Akt. In invasive breast cancer specimens, Rictor expression was upregulated significantly compared with nonmalignant tissues. In a HER2/Neu mouse model of breast cancer, genetic ablation of Rictor decreased cell survival and phosphorylation at S473 on Akt, delaying tumor latency, penetrance, and burden. In HER2-amplified cells, exposure to an mTORC1/2 dual kinase inhibitor decreased Akt-dependent cell survival, including in cells resistant to lapatinib, where cytotoxicity could be restored. We replicated these findings by silencing Rictor in breast cancer cell lines, but not silencing the mTORC1 cofactor Raptor (RPTOR). Taken together, our findings establish that Rictor/mTORC2 signaling drives Akt-dependent tumor progression in HER2-amplified breast cancers, rationalizing clinical investigation of dual mTORC1/2 kinase inhibitors and developing mTORC2-specific inhibitors for use in this setting. Cancer Res; 76(16); 4752–64. ©2016 AACR.
Monday, August 15, 2016 12:05 AM|Bai, Y., Yu, Z.-H., Liu, S., Zhang, L., Zhang, R.-Y., Zeng, L.-F., Zhang, S., Zhang, Z.-Y.|Cancer Research recent issues|Labels: AKT, skin cancer
Phosphatase of regenerating liver (PRL) oncoproteins are phosphatases overexpressed in numerous types of human cancer. Elevated levels of PRL associate with metastasis and poor clinical outcomes. In principle, PRL phosphatases offer appealing therapeutic targets, but they remain underexplored due to the lack of specific chemical probes. In this study, we address this issue by exploiting a unique property of PRL phosphatases, namely, that they may function as homotrimers. Starting from a sequential structure-based virtual screening and medicinal chemistry strategy, we identified Cmpd-43 and several analogs that disrupt PRL1 trimerization. Biochemical and structural analyses demonstrate that Cmpd-43 and its close analogs directly bind the PRL1 trimer interface and obstruct PRL1 trimerization. Cmpd-43 also specifically blocks the PRL1-induced cell proliferation and migration through attenuation of both ERK1/2 and Akt activity. Importantly, Cmpd-43 exerted potent anticancer activity both in vitro and in vivo in a murine xenograft model of melanoma. Our results validate a trimerization-dependent signaling mechanism for PRL and offer proof of concept for trimerization inhibitors as candidate therapeutics to treat PRL-driven cancers. Cancer Res; 76(16); 4805–15. ©2016 AACR.
Monday, August 15, 2016 12:05 AM|Ice, R., Kiseleva, A., Loskutov, Y., Smolkin, M., Salkeni, A., Hazard, H., Layne, G., Pugacheva, E.|Clinical Cancer Research recent issues|Labels: AKT, aurora, biomarker diagnostic

Background: Although advances in treating early stage breast cancers have increased the overall survival rate, once the disease has metastasized treatment options subside to palliative care. The limited access to metastatic biopsies and disease-relevant pre-clinical models to test new therapeutics targeted against advanced metastatic cancers limits progress and translation of investigational therapeutics to the clinic.

Methods: To address this deficiency we developed a collection of metastatic patient derived xenograft models via direct transplantation of metastatic biopsy or residual surgical material in immunocompromised mice. We successfully collected and established triple negative as well as ER/PR positive patient xenografts which are available for collaborative research. We further characterized and utilized the PDXs to assess the efficacy of new combination therapy to treat distant metastases.

Results: The efficacy of Aurora A kinase inhibition by small molecule inhibitor MLN8237 (Alisertib) as monotherapy and in combination with microtubule targeting drug, eribulin, on different stages of metastasis and potential mechanisms of its action was defined. Our work using PDX models indicates that Alisertib does not limit growth of the primary tumor. These findings are similar to the results of clinical trials with Alisertib in breast cancer. Importantly, we found that Alisertib dramatically decreases growth of the established metastases and prevents further dissemination via inactivation of AKT and activation of cytotoxic autophagy. Combination of Alisertib with eribulin led to a synergistic decrease in metastases to distant organs and provided additional local control of mammary tumor growth.

Conclusion: Metastatic PDX models provide new, accurate assessment of anti-metastatic regiment's efficacy. MLN8237 plus eribulin combination shows synergistic inhibition of metastatic spread, growth of established metastases and prolongs overall survival. Future clinical trials are needed to further test this regiment in clinic to improve survival of metastatic cancer patients.

Citation Format: Ryan Ice, Anna Kiseleva, Yuriy Loskutov, Matthew Smolkin, Adham Salkeni, Hannah Hazard, Ginger Layne, Elena Pugacheva{Authors}. Development of metastatic patient-derived xenografts (PDXs) for accurate assessment of anti-metastatic therapeutics in pre-clinical settings. [abstract]. In: Proceedings of the AACR Special Conference: Patient-Derived Cancer Models: Present and Future Applications from Basic Science to the Clinic; Feb 11-14, 2016; New Orleans, LA. Philadelphia (PA): AACR; Clin Cancer Res 2016;22(16_Suppl):Abstract nr B20.

Monday, August 15, 2016 12:05 AM|Bexell, D., Braekeveldt, N., Mohlin, S., Wigerup, C., Gisselsson, D., Tadeo, I., Berbegall, A. P., Navarro, S., Noguera, R., Pahlman, S.|Clinical Cancer Research recent issues|Labels: AKT, biomarker diagnostic

Background: We previously established neuroblastoma patient-derived orthotopic xenografts (PDXs) by implanting patient neuroblastoma fragments into immunodeficient NSG mice. SNP array analysis confirmed that PDXs maintain patient-specific chromosomal aberrations 1p del, MYCN amp and 17q gain. Immunohistochemistry showed that PDXs retain neuroblastoma markers and a highly infiltrative growth pattern. Importantly, we found spontaneous distant metastasis to lungs, liver and bone marrow. In vitro cultures established from the PDXs express neuroblastoma markers and retain their tumorigenic and metastatic ability in vivo after orthotopic injection.

Methods and Results: Given the important role of the tumor stroma for tumor progression and treatment response, we examined PDX stroma by immunohistochemistry. PDXs were highly vascularized with mouse endothelial cells and two PDX models also formed tumor vasculature by co-engrafted human tumor endothelial cells. Tumors contained pericytes, cancer-associated fibroblasts, macrophages and extracellular components resembling the patient disease. PDXs established in athymic nude mice additionally developed intratumoral lymphatic vessels and contained mouse-derived CD45+ lymphoid cells. Thus, PDXs reflect important tumor microenvironment hallmarks for high-stage neuroblastoma. Furthermore, we demonstrate the feasibility of using short-term in vitro cultured PDX-derived cells as a drug-testing model, and show that the HIF2A oncogene is transcriptionally regulated at hypoxia via the PI3K/mTORC2 pathway in these cells. The results establish the PI3K and mTORC2 pathways as potential therapeutic targets of aggressive neuroblastoma.

Conclusion: Neuroblastoma orthotopic PDXs reflect clinical aspects of high-risk disease including spontaneous metastasis, copy number changes and microenvironmental hallmarks. Neuroblastoma PDXs are relevant models for in vitro and in vivo preclinical drug testing.

Citation Format: Daniel Bexell, Noémie Braekeveldt, Sofie Mohlin, Caroline Wigerup, David Gisselsson, Irene Tadeo, Ana P. Berbegall, Sam Navarro, Rosa Noguera, Sven Påhlman. Neuroblastoma patient-derived orthotopic xenografts: Clinically relevant models for drug testing. [abstract]. In: Proceedings of the AACR Special Conference: Patient-Derived Cancer Models: Present and Future Applications from Basic Science to the Clinic; Feb 11-14, 2016; New Orleans, LA. Philadelphia (PA): AACR; Clin Cancer Res 2016;22(16_Suppl):Abstract nr B23.

Monday, August 15, 2016 12:05 AM|Tominaga, K., Gotoh, N.|Clinical Cancer Research recent issues|Labels: AKT, IGFR, NFKb, breast cancer, biomarker diagnostic

An inflammatory microenvironment contributes to tumorigenesis. The pro-inflammatory transcription factor nuclear factor-kappa B (NF-kappa B) is known to play important roles, but how it regulates cancer stem cells (CSCs) remains largely unclear. We comprehensively analyzed which targets of NF-kappa B are activated by heregulin (HRG), a tumor sphere-forming ligand, in breast cancer cells. We identified many cytokines downstream of HRG-phosphatidyl inositol 3 kinase (PI3K)-NF-kappa B signaling. Insulin-like growth factor 2 (IGF2) was identified as a key downstream target; IGF2 treatment induced tumor spheres in most samples of patient-derived primary breast cancer cells, and anti-IGF2 antibody treatment greatly reduced HRG-induced tumor sphere formation, even though many other cytokines were simultaneously produced. The IGF2 receptor, IGF-1R, was specifically expressed at high levels in CSC-enriched populations in freshly obtained primary breast cancer cells. Moreover, IGF2-PI3K signaling induced expression of a stemness transcription factor, ID1, and IGF2 itself. ID1 knockdown greatly reduced IGF2 expression, and tumor sphere formation. Finally, treatment with anti-IGF1/2 antibodies blocked tumorigenesis derived from the IGF1Rhigh CSC-enriched population in a patient-derived xenograft (PDX) model. Thus, NF-kappa B may trigger IGF2-ID1-IGF2 positive feedback circuits and PI3K-mediated feed-forward circuits that allow cancer stem-like cells to appear; it may then stabilize the feedback circuits, to which the cancer stem-like cells become addicted. Because the stemness circuits may be the Achilles' heels of CSCs, it will be critical to break them for eradication of CSCs.

Citation Format: Kana Tominaga, Noriko Gotoh. Addiction to the NF-B–triggered IGF2-ID1-IGF2 circuit for maintenance of the breast cancer stem-like cells. [abstract]. In: Proceedings of the AACR Special Conference: Patient-Derived Cancer Models: Present and Future Applications from Basic Science to the Clinic; Feb 11-14, 2016; New Orleans, LA. Philadelphia (PA): AACR; Clin Cancer Res 2016;22(16_Suppl):Abstract nr A27.

Monday, August 15, 2016 12:05 AM|Evans, K. W., Yuca, E., Scott, S. M., Paez, N. A., Zheng, X., Chen, K., Gonzales, L., Tapia, C., Tarco, E., Black, D. M., Mills, G. B., Meric-Bernstam, F.|Clinical Cancer Research recent issues|Labels: AKT, mTOR, PARP, breast cancer, biomarker diagnostic, clinical trial

Introduction: Patients with triple negative breast cancer (TNBC) that do not respond to cytotoxic neoadjuvant therapy have a poor prognosis, thus there is a pressing need to develop pre-clinical models of chemoresistant TNBC and identify optimal therapeutic targets. Patient-derived xenografts (PDX) are a simple, expandable approach to model TNBC in vivo. We have generated a collection of triple negative PDXs that have undergone molecular characterization at the DNA, RNA and protein levels and have initiated characterization of their therapeutic sensitivity to standard chemotherapeutics regimens as well as targeted therapies.

Methods: Tumors from patients and matching PDXs have been characterized by cancer-specific targeted exome sequencing, RNA sequencing, and Reverse Phase Protein Arrays. We have established single agent sensitivities for a set of PDXs to standard TNBC therapies (paclitaxel, carboplatin, doxorubicin, eribulin, gemcitabine) and the following targeted therapies: talazoparib (PARP), MLN0128 (mTOR), buparlisib (PI3K), and trametinib (MEK1/2).

Results: We have generated 25 hormone receptor-low/HER2- PDXs from 24 patients (1 primary-local recurrence pair) with an overall engraftment rate of 49% for this patient population. Exome sequencing found that the PDXs mostly maintain the somatic mutation profile of the originating tumor and exhibit alterations common to TNBC: 16 (73%) with TP53 mutations, 2 (9%) with PI3KCA mutations and 4 (18%) with PTEN deletions. RNA sequencing demonstrated that the PDXs maintain gene expression profiles similar to the originating tumor and that our panel is comprised of PDXs representative of five TNBC molecular subtypes. Treatment with standard therapies established differential sensitivity to paclitaxel and carboplatin between PDXs. The two models with PI3KCA alterations were responsive to mTOR/PI3K inhibition and unresponsive to trametinib and talazoparib, supporting heightened reliance on mTOR/PI3K signaling in PI3KCA mutant TNBC. Talazoparib was the only targeted agent tested that caused regression as a single agent in any model. All three models that regressed with talazoparib treatment had genetic alterations linked to DNA damage pathways (BRCA1 germline alteration, ATM deletion; PTEN deletion); these models also had low BRCA1 mRNA expression and were the only PDXs to regress when treated with carboplatin.

Conclusions: PDXs of all TNBC subtypes can be generated from TNBC patients that are resistant to neoadjuvant chemotherapy. These PDXs maintain molecular alterations of TNBC, retain patient-specific gene expression, and display differential response to therapies enabling identification of associations between responses and molecular traits.

Citation Format: Kurt W. Evans, Erkan Yuca, Stephen M. Scott, Natalia Arango Paez, Xiaofeng Zheng, Ken Chen, Laura Gonzales, Coya Tapia, Emily Tarco, Dalliah M. Black, Gordon B. Mills, Funda Meric-Bernstam. Patient-derived xenografts to test emerging therapies for triple negative breast cancer. [abstract]. In: Proceedings of the AACR Special Conference: Patient-Derived Cancer Models: Present and Future Applications from Basic Science to the Clinic; Feb 11-14, 2016; New Orleans, LA. Philadelphia (PA): AACR; Clin Cancer Res 2016;22(16_Suppl):Abstract nr A39.

Friday, August 12, 2016 2:22 AM|Shinichiro Tahara, Satoshi Nojima, Kenji Ohshima, Yumiko Hori, Masako Kurashige, Naoki Wada, Jun-ichiro Ikeda, Eiichi Morii|Cancer Science|Labels: AKT, endometrial cancer
Endometrioid carcinoma (EC) is one of the most common malignancies of the female genital system. Although the behavior of EC ranges from an excellent prognosis to aggressive disease with a poor outcome, the factors that determine its diversity have not been determined. Here, we show that S100A4, a calcium-binding protein of the EF-hand type, is correlated with the proliferation and invasion ability of EC. We demonstrated previously that EC cells with high aldehyde dehydrogenase (ALDH) activity were more tumorigenic than ALDH-lo cells. Screening by shotgun proteomics demonstrated that the expression level of S100A4 in ALDH-hi EC cells was significantly higher than that in ALDH-lo cells. S100A4-knockout cells generated by the CRISPR/Cas9 system showed reduced proliferation and invasion. These cells showed impaired AKT phosphorylation and matrix metalloproteinase-2 activation, accounting for their impaired proliferation and invasion, respectively. Furthermore, in clinical EC samples, elevated expression of S100A4 was highly related to myometrial and lymphatic invasion in well to moderately differentiated EC. Notably, strong and diffuse expression of S100A4 was observed in tumor tissues with a microcystic, elongated and fragmented (“MELF”) pattern, which is associated with a highly invasive EC phenotype. Collectively, our results demonstrate not only that high expression of S100A4 contributes to an aggressive phenotype of EC, but also that its elevated expression is closely related to the MELF histopathological pattern. In clinical patients-derived EC samples, elevated expression of S100A4 was highly related to the frequency of myometrial invasion and lymphatic invasion in well- to moderately-differentiated EC. Notably, strong and diffuse staining pattern of S100A4 was observed in ‘MELF’, which is a particular histological pattern associated with highly invasive phenotype of EC.
Monday, August 8, 2016 12:39 PM|Mei, Q., Li, X., Zhang, K., Wu, Z., Li, X., Meng, Y., Guo, M., Luo, G., Fu, X., Han, W.|Clinical Cancer Research Online First Articles|Labels: AKT, cervical cancer

Purpose: Loss of Chr9q31-33 is one of the most common chromosome imbalances of cervical cancer, but the underlying mechanism has not been well documented. Experimental Design: The loss of heterozygosity (LOH) status of Chr9q31-33 was investigated utilizing 26 microsatellite markers. We detected the expression of miR-181a2/181b2 by qRT-PCR analysis of cervical cancer cell lines and 100 paired tumor samples and corresponding adjacent non-tumor tissues. Kaplan-Meier and Cox proportional hazard regression analysis were performed to identify the prognostic value of miR-181a2/181b2. Regulation of expression was analyzed by methylation-specific PCR. The tumor suppressing effects of miR-181a2/181b2 were determined in vitro and in vivo. The target gene and signaling pathway mediated the function of miR-181a2/181b2 were also identified. Results: Chr9q33.3 was identified as one of the most deleted regions in cervical cancer. Under-expression of miR-181a2/181b2 was detected in 46% of cervical caner, and was induced by LOH of chr9q33.3 and promoter hypermethylation. Attenuated miR-181a2/181b2 expression predicted a poor prognostic phenotype and advanced clinical stage of cervical cancer. miR-181a2/181b2 prominently dampened cell cycle progression, suppressed cell growth and promoted apoptosis of tumor cells in vitro. They also effectively impeded tumor formation and growth in vivo. miR-181a2/181b2 exert the tumor suppressor ability by depressing direct target PIK3R3 (p55) and consequently modulating PIK3R3/Akt/FoxO signaling pathway. Conclusions: We demonstrated a cause-and-effect event beginning from loss of chr9q33.3, a frequent event in cervical cancer, to the under-expression of miR-181a2/181b2, leading to the elevated activation of PI3K pathway.

Thursday, August 4, 2016 8:57 AM|Yang, X., Li, J., Li, X., Liang, Z., Gao, W., Liang, J., Cheng, S., Lin, Y.|JNM Ahead of Print|Labels: AKT, BRAF

Telomerase Reverse Transcriptase (TERT) promoter mutation has been reported to be associated with aggressive characteristics in differentiated thyroid cancer (DTC). This study examined the status of TERT promoter mutation in distant metastatic DTC (DM-DTC), and evaluated the correlation between TERT mutation and radioactive iodine-131(RAI) uptake, as well as that between TERT mutation and therapy response. Methods: TERT promoter and B-Raf proto-oncogene (BRAF) V600E mutation were retrospectively examined in primary tumors of 66 DM-DTC patients. Stimulated thyroglobulin (sTg) changes, RAI uptake status (avid or non-avid), and other imaging evidence were analyzed to evaluate therapy response. After a median follow-up of 46.5 months (interquartile range, 29.0 to 70.5 months), therapy response was classified as disease control and refractory. Results: The prevalence of TERT mutations was 22.73% (15/66), of which C228T mutation was more prevalent (13/15) than C250T mutation (2/15). Rising sTg was noticed in 93.33% (14/15) of TERT mutation group. While in cases with both mutations negative, 78.12 % (25/32) presented with decreased sTg. TERT mutation closely correlated with poor RAI therapy response (p<0.001), and all 15 patients were classified as refractory to RAI with a positive predictive value of 100% at the end point of follow-up. TERT mutation was associated with older mean age at diagnosis (p<0.001), larger mean tumor diameter (P = 0.013), and more likelihood of both BRAF mutation coexistence (P = 0.044) and refractory to RAI (p<0.001). In the 36 cases received imaging semi-quantitative analysis, it was found that TERT mutation significantly correlated with non-RAI-avidity, with a much lower mean tumor/background (T/B) ratio (obtained from post RAI therapy whole-body scanning) than TERT wild-type (p<0.001). And DM-DTC patients with TERT mutation were more likely to lose RAI-avidity at initial RAI therapy than those with only BRAF mutation (8/8 vs 5/11, Fisher’s exact test, P = 0.018). Conclusion: TERT promoter mutation closely associates with non-RAI-avidity in DM-DTC, and when comparing with BRAF mutation, TERT mutation manifested a worse negative influence on RAI uptake. It could also be used as a predictive marker to early identify refractory to RAI.

Thursday, August 4, 2016 8:57 AM|Nock, B. A., Kaloudi, A., Lymperis, E., Giarika, A., KULKARNI, H. R., Klette, I., Singh, A., Krenning, E. P., de Jong, M., Maina-Nock, T., Baum, R. P.|JNM Ahead of Print|Labels: AKT, prostate cancer

We have recently introduced the potent GRPR-antagonist [68Ga]SB3 ([68Ga-DOTA-p-aminomethylaniline-diglycolic acid-DPhe-Gln-Trp-Ala-Val-Gly-His-Leu-NHEt), showing excellent tumor localizing efficacy in animal models and in patients. By replacement of the C-terminal the novel GRPR-antagonist NeoBOMB1 was generated and labeled with different radiometals for theranostic use. We herein report on the biological profile of resulting [67/68Ga/111In/177Lu]NeoBOMB1 radioligands in GRPR-expressing cells and mouse models. First evidence of prostate cancer lesion visualization in man with [68Ga]NeoBOMB1 and PET/CT is also presented. Methods: NeoBOMB1 was radiolabeled with 67/68Ga, 111In and 177Lu according to published protocols. The respective metalated species [natGa/natIn/natLu]NeoBOMB1 were also synthesized and used in competition binding experiments against [125I-Tyr4]BBN in GRPR-positive PC-3 cell membranes. Internalization of [67Ga/111In/177Lu]NeoBOMB1 radioligands was studied in PC-3 cells at 370C and their metabolic stability in peripheral mouse blood was determined by HPLC-analysis of blood samples. Biodistribution was performed by injecting a [67Ga/111In/177Lu]NeoBOMB1 bolus (74 kBq/74 kBq /370 kBq, respectively, 100 µL, 10 pmol total peptide ±40 nmol [Tyr4]BBN: for in vivo GRPR-blockade) in SCID mice bearing PC-3 xenografts. PET/CT images with [68Ga]NeoBOMB1 were acquired in prostate cancer patients. Results: NeoBOMB1 and [natGa/natIn/natLu]NeoBOMB1 bound to GRPR with high affinity (IC50: 1-2 nM). [67Ga/111In/177Lu]NeoBOMB1 specifically and strongly bound on the cell-membrane of PC-3 cells displaying low internalization, as expected for receptor antagonists. They showed excellent metabolic stability in peripheral mouse blood (>95% intact at 5 min postinjection (pi)). After injection in mice, all three [67Ga/111In/177Lu]NeoBOMB1 showed comparably high and GRPR-specific uptake in the PC-3 xenografts (e.g. 30.6±3.9%ID/g, 28.6±6.0%ID/g and >35%ID/g at 4 h pi, respectively), clearing from background predominantly via the kidneys. During a translational study in prostate cancer patients [68Ga]NeoBOMB1 rapidly localized in pathological lesions achieving high contrast imaging. Conclusion: The GRPR-antagonist radioligands [67Ga/111In/177Lu]NeoBOMB1, independent of the radiometal applied, have shown comparable behavior in prostate cancer models, in favor of future theranostic use in GRPR-positive cancer patients. Such translational prospects were further supported by the successful visualization of prostate cancer lesions in man applying [68Ga]NeoBOMB1 and PET/CT.

Tuesday, August 2, 2016 12:05 AM|Kaneda, M. M., Cappello, P., Nguyen, A. V., Ralainirina, N., Hardamon, C. R., Foubert, P., Schmid, M. C., Sun, P., Mose, E., Bouvet, M., Lowy, A. M., Valasek, M. A., Sasik, R., Novelli, F., Hirsch, E., Varner, J. A.|Cancer Discovery recent issues|Labels: AKT, pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is a devastating disease with a low 5-year survival rate, yet new immunotherapeutic modalities may offer hope for this and other intractable cancers. Here, we report that inhibitory targeting of PI3K, a key macrophage lipid kinase, stimulates antitumor immune responses, leading to improved survival and responsiveness to standard-of-care chemotherapy in animal models of PDAC. PI3K selectively drives immunosuppressive transcriptional programming in macrophages that inhibits adaptive immune responses and promotes tumor cell invasion and desmoplasia in PDAC. Blockade of PI3K in PDAC-bearing mice reprograms tumor-associated macrophages to stimulate CD8+ T-cell–mediated tumor suppression and to inhibit tumor cell invasion, metastasis, and desmoplasia. These data indicate the central role that macrophage PI3K plays in PDAC progression and demonstrate that pharmacologic inhibition of PI3K represents a new therapeutic modality for this devastating tumor type.

Significance: We report here that PI3K regulates macrophage transcriptional programming, leading to T-cell suppression, desmoplasia, and metastasis in pancreas adenocarcinoma. Genetic or pharmacologic inhibition of PI3K restores antitumor immune responses and improves responsiveness to standard-of-care chemotherapy. PI3K represents a new therapeutic immune target for pancreas cancer. Cancer Discov; 6(8); 870–85. ©2016 AACR.

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Tuesday, August 2, 2016 12:05 AM|Unknown Author|Cancer Discovery recent issues|Labels: AKT, EGFR, brain cancer

Combined inhibition of PI3K and mTORC1 abolished mTORC1 signaling, inducing tumor regression.

Monday, August 1, 2016 12:05 AM|Sridharan, V., Gjini, E., Liao, X., Chau, N. G., Haddad, R. I., Severgnini, M., Hammerman, P., El-Naggar, A., Freeman, G. J., Hodi, F. S., Rodig, S. J., Dranoff, G., Schoenfeld, J. D.|Cancer Immunology Research recent issues|Labels: AKT, PD-1/PD-L1, WNT

Adenoid cystic carcinoma (ACC) is among the most lethal salivary gland tumors, with no treatments for metastatic disease that prolong survival. We examined tissue from 28 primary and metastatic ACC deposits obtained from 21 patients for infiltrating immune cells and PD-L1/PD-L2 expression and determined mRNA profiles of over 1,400 oncogenic and immune-related genes. We also assessed the effect of chemoradiation on immune mediators in a patient who had serial biopsies available. Most tumors expressed PD-L2 but had few infiltrating immune cells. Lack of immune-cell infiltrate was associated with expression of genes in the β-catenin/Wnt and PI3K pathways. Additionally, certain transcripts linked to growth and invasion were differentially expressed among primary and metastatic deposits. Chemoradiation appeared to increase CD8+ effector T cells, decrease regulatory T cells, and promote a systemic humoral response. These data suggest a potential role for PD-L2 inhibition and immune modulation as treatment for patients with ACC. Cancer Immunol Res; 4(8); 679–87. ©2016 AACR.

Wednesday, July 27, 2016 1:11 PM|SUMIDA, T., KAMATA, Y., KOBAYASHI, Y., ISHIKAWA, A., MORI, Y.|Anticancer Research recent issues|Labels: AKT, IGFR, salivary duct cancer

Background: Inhibitor of differentiation or DNA binding 1 (ID1) is overexpressed in human salivary gland cancer (SGC). The insulin growth factor (IGF) system is an attractive target in cancer control because it is associated with various cancer progressions. Materials and Methods: The human SGC cell line HSY with abundant ID1 was used. ID1 knockdown and its effect on the IGF system were investigated. Cell proliferation and invasion, as well as associated protein expression, were analyzed. Phospho-AKT was also evaluated. Results: ID1 knockdown reduced cell proliferation and invasion, while the expression of proteins associated with malignant phenotypes was altered. IGF-II expression was suppressed, suggesting that this system is one of the mechanisms underlying effects of ID1 in SGC cells. c-Myc was up-regulated, whereas p21 and p27 were down-regulated. Moreover, phospho-AKT was reduced in ID1-knockeddown cells. Conclusion: ID1 down-regulation induced parallel changes in the IGF and AKT pathways. The crosstalk of these pathways may enhance malignant phenotypes in SGCs.

Monday, July 25, 2016 5:29 AM|Han-Gyeul Kim; Jiwon Ahn; Ho-Joon Lee; Sae-Bhom Lee; Misun Won; Cho-Rock Jung; Joo-Young Im; Bo-Kyung Kim; Seung-Kiel Park; Myung Jin Son; Kyung-Sook Chung|JournalTOCs API - Biochimica et Biophysica Acta (BBA) - Molecular Cell Research (50 articles)|Labels: AKT, HDAC, lung cancer

Shikonin induces apoptosis of lung cancer cells via activation of FOXO3a/EGR1/SIRT1 signaling antagonized by p300
Yun-Ji Jeung Han-Gyeul Kim; Jiwon Ahn; Ho-Joon Lee; Sae-Bhom Lee; Misun Won; Cho-Rock Jung; Joo-Young Im; Bo-Kyung Kim; Seung-Kiel Park; Myung Jin Son; Kyung-Sook Chung
Biochimica et Biophysica Acta (BBA) - Molecular Cell Research, Vol. 1863, No. 11 (2016) pp. 2584 - 2593
Publication date: Available online 21 July 2016 Source:Biochimica et Biophysica Acta (BBA) - Molecular Cell Research Author(s): Yun-Ji Jeung, Han-Gyeul Kim, Jiwon Ahn, Ho-Joon Lee, Sae-Bhom Lee, Misun Won, Cho-Rock Jung, Joo-Young Im, Bo-Kyung Kim, Seung-Kiel Park, Myung Jin Son, Kyung-Sook Chung Shikonin derivatives exert powerful cytotoxic effects including induction of apoptosis. Here, we demonstrate the cytotoxic efficacy of shikonin in vivo in xenograft models, which did not affect body weight as well as its reduction of cell viability in vitro using several non-small cell lung cancer (NSCLC) cell lines. We found that inhibition of AKT by shikonin activated the forkhead box (FOX)O3a/early growth response protein (EGR)1 signaling cascade and enhanced the expression of the target gene Bim, leading to apoptosis in lung cancer cells. Overexpression of wild-type or a constitutively active mutant of FOXO3a enhanced shikonin-induced Bim expression. The NAD+− dependent histone deacetylase sirtuin (SIRT)1 amplified the pro-apoptotic effect by deacetylating FOXO3a, which induced EGR1 binding to the Bim promoter and activated Bim expression. Meanwhile, PI3K/AKT activity was enhanced, whereas that of FOXO3a was reduced and p300 was upregulated by treatment with a sublethal dose of shikonin. FOXO3a acetylation was enhanced by p300 overexpression, while shikonin-induced Bim expression was suppressed by p300 overexpression, which promoted cell survival. FOXO3a acetylation was increased by p300 overexpression and treatment with SIRT1 inhibitor, improving cell survival. In addition, shikonin-induced FOXO3a nuclear localization was blocked by AKT activation and SIRT1 inhibition, which blocked Bim expression and conferred resistance to the cytotoxic effects of shikonin. The EGR1 increase induced by shikonin was restored by pretreatment with SIRT1 inhibitor. These results suggest that shikonin induces apoptosis in some lung cancer cells via activation of FOXO3a/EGR1/SIRT1 signaling, and that AKT and p300 negatively regulate this process via Bim upregulation.

Tuesday, July 19, 2016 11:22 AM|Qian, D. C., Xiao, X., Byun, J., Suriawinata, A. A., Her, S., Amos, C. I., Barth, R.|Clinical Cancer Research Online First Articles|Labels: AKT, mTOR, CRC

Purpose: We have previously demonstrated that metastatic colorectal cancer patients who exhibit immune responses to a dendritic cell (DC) vaccine have superior recurrence-free survival following surgery, compared to patients in whom responses do not occur. We sought to characterize the patterns of T lymphocyte infiltration and somatic mutations in metastases that are associated with and predictive of response to the DC vaccine. Experimental Design: Cytotoxic, memory, and regulatory T cells in resected metastases and surrounding normal liver tissue from 22 patients (11 responders and 11 non-responders) were enumerated by immunohistochemistry prior to vaccine administration. In conjunction with tumor sequencing, the Combined Multivariate and Collapsing method was used to identify gene mutations that are associated with vaccine response. We also derived a response prediction score for each patient using his/her tumor genotype data and variant association effect sizes computed from the other 21 patients; greater weighting was placed on gene products with cell membrane-related functions. Results: There was no correlation between vaccine response and intra-tumor, peri-tumor, or hepatic densities of T cell subpopulations. Associated genes were found to be enriched in the PI3K/Akt/mTOR signaling axis (P < 0.001). Applying a consistent prediction score cutoff over 22 rounds of leave-one-out cross-validation correctly inferred vaccine response in 21 of 22 patients (95%). Conclusions: Adjuvant dendritic cell vaccination has shown promise as a form of immunotherapy for patients with metastatic colorectal cancer. Its efficacy may be influenced by somatic mutations that affect pathways involving PI3K, Akt, and mTOR, as well as tumor surface proteins.

Thursday, July 14, 2016 9:39 AM|Mendler, C. T., Feuchtinger, A., Heid, I., Aichler, M., D'Alessandria, C., Pirsig, S., Blechert, B., Wester, H.-J., Braren, R., Walch, A., Skerra, A., Schwaiger, M.|JNM Ahead of Print|Labels: AKT, HL

Antibodies have become an established treatment modality in cancer therapy during the last decade. However, these treatments often suffer from insufficient and heterogeneous response despite validated antigen or target receptor expression in the tumor. In fact, therapeutic success depends both on the presence and accessibility of the tumor antigen by the antibody. In search of a suitable preclinical animal model to evaluate the mechanisms of tumor heterogeneity and hemodynamics, we characterized two exemplary non-Hodgkin lymphoma subtypes with comparable CD20 expression and metabolism, SUDHL-4 and Granta, using multimodal imaging techniques. Methods: To investigate in vivo biodistribution, two differently modified αCD20 antigen-binding fragments (Fab), prepared (i) by PASylation and (ii) by fusion with an albumin-binding domain (ABD), were radiolabeled with 125I and intravenously injected into immunocompromised mice bearing corresponding xenografts. Results: Validation with 18F-FDG revealed similar distribution of vital tumor tissue 1 h p.i. However, large differences in tumor uptake were observed when applying the CD20-specific radiotracers 125I-Fab-ABD and 125I-Fab-PAS200 with 12.3 and 2.4 % ID/g, respectively, for Granta in comparison with 3.5 and 0.75 % ID/g, respectively, for SUDHL-4 xenografts 24 h p.i. 3D light-sheet fluorescence microscopy with Cy5-Fab-PAS200 confirmed better tracer extravasation in the Granta tumors. Moreover, dynamic contrast enhanced MRI imaging revealed significantly reduced tumor perfusion in the SUHDL-4 xenografts. Conclusion: Tracer uptake was highly dependent on local tumor perfusion as well as Fab permeation in the SUDHL-4 and Granta tumors. Thus, the SUDHL-4 xenograft offers an excellent model system to investigate the influence of therapies affecting tumor angiogenesis.

Tuesday, July 12, 2016 11:13 AM|Zhang, J.-X., Chen, Z.-H., Xu, Y., Chen, J.-W., Weng, H.-W., Yun, M., Zheng, Z.-S., Chen, C., Wu, B.-L., Li, E.-m., Fu, J.-H., Ye, S., Xie, D.|Clinical Cancer Research Online First Articles|Labels: AKT, biomarker diagnostic

Purpose: We previously reported the oncogenic role of paired-like homeodomain 2 (PITX2) in esophageal squamous cell carcinoma (ESCC). In this study, we aimed to identify the microRNA (miRNA) regulators of PITX2 and the mechanism underlying the pathogensis of ESCC. Experimental Design: Using miRNA profiling and bioinformatics analyses, we identified miR-644a as a negative mediator of PITX2 in ESCC. A series of in vivo and in vitro assays were performed to confirm the effect of miR-644a on PITX2-mediated ESCC malignancy. Results: ESCC cells and tissues expressed less miR-644a than normal epithelial controls. In patient samples, lower expression of miR-644a in ESCC tissues was significantly correlated with tumor recurrence and/or metastasis, such that MiR-644a, PITX2 and the combination of the two were independent prognostic indicators for ESCC patient's survival (P<0.05). Gain- and loss-of-function studies demonstrated that miR-644a inhibited ESCC cell growth, migration and invasion in vitro and suppressed tumor growth and metastasis in vivo. In addition, miR-644a dramatically suppress self-renewal and stem cell-like traits in ESCC cells. Further, the effect of up-regulation of miR-644a was similar to that of PITX2 knockdown in ESCC cells. Mechanistic studies revealed that miR-664a attenuates ESCC cells' malignancy and stem-cell-associated phenotype, at least partially, by inactivation of the Akt/GSK-3β/β-catenin signaling pathway through PITX2. Furthermore, promoter hypermethylation caused down-regulation of miR-644a in ESCC. Conclusions: Down-regulation of miR-644a plays an important role in promoting both aggressiveness and stem-like traits of ESCC cells, suggesting that miR-644a may be useful as a novel prognostic biomarker or therapeutic target for the disease.

Friday, July 1, 2016 9:56 AM|Zook, P., Pathak, H. B., Belinsky, M., Gersz, L., Devarajan, K., Zhou, Y., Godwin, A. K., von Mehren, M., Rink, L. A.|Clinical Cancer Research Online First Articles|Labels: AKT, Bcr-Abl, GIST

Purpose: Gastrointestinal stromal tumors (GIST) generally harbor activating mutations in the receptor tyrosine kinase KIT or in the related platelet derived growth factor receptor alpha (PDGFRA). GIST treated with imatinib mesylate (IM) or second-line therapies that target mutant forms of these receptors generally escape disease control and progress over time. Inhibiting additional molecular targets may provide more substantial disease control. Recent studies have implicated the PI3-kinase/AKT pathway in the survival of IM-resistant GIST cell lines and tumors. Experimental Design: Here, we performed in vitro and in vivo studies evaluating the novel combination of IM with the AKT inhibitor MK-2206 in GIST. Whole-transcriptome sequencing (WTS) of xenografts was performed to explore the molecular aspects of tumor response to this novel combination and to potentially identify additional therapeutic targets in GIST. Results: This drug combination demonstrated significant synergistic effects in a panel of IM-sensitive and -resistant GIST cell lines. Furthermore, combination therapy provided significantly greater efficacy, as measured by tumor response and animal survival, in IM-sensitive GIST xenografts as compared to treatment with IM or MK-2206 alone. WTS implicated two neural genes, brain expressed X-linked 1 (BEX1) and neuronal pentraxin I (NPTX1), whose expression was significantly up-regulated in combination-treated tumors compared to tumors treated with the two monotherapies. Conclusion: These studies provide strong preclinical justification for combining IM with an AKT inhibitor as a front-line therapy in GIST. In addition, the WTS implicated the BCL-2/BAX/BAD apoptotic pathway as a potential mechanism for this enhanced combination effect.

Friday, July 1, 2016 12:05 AM|Kitai, H., Ebi, H., Tomida, S., Floros, K. V., Kotani, H., Adachi, Y., Oizumi, S., Nishimura, M., Faber, A. C., Yano, S.|Cancer Discovery recent issues|Labels: AKT, FGFR, MapK, lung cancer

KRAS is frequently mutated in lung cancer. Whereas MAPK is a well-known effector pathway of KRAS, blocking this pathway with clinically available MAPK inhibitors is relatively ineffective. Here, we report that epithelial-to-mesenchymal transition rewires the expression of receptor tyrosine kinases, leading to differential feedback activation of the MAPK pathway following MEK inhibition. In epithelial-like KRAS-mutant lung cancers, this feedback was attributed to ERBB3-mediated activation of MEK and AKT. In contrast, in mesenchymal-like KRAS-mutant lung cancers, FGFR1 was dominantly expressed but suppressed by the negative regulator Sprouty proteins; MEK inhibition led to repression of SPRY4 and subsequent FGFR1-mediated reactivation of MEK and AKT. Therapeutically, the combination of a MEK inhibitor (MEKi) and an FGFR inhibitor (FGFRi) induced cell death in vitro and tumor regressions in vivo. These data establish the rationale and a therapeutic approach to treat mesenchymal-like KRAS-mutant lung cancers effectively with clinically available FGFR1 and MAPK inhibitors.

Significance: Adaptive resistance to MEKi is driven by receptor tyrosine kinases specific to the differentiation state of the KRAS-mutant non–small cell lung cancer (NSCLC). In mesenchymal-like KRAS-mutant NSCLC, FGFR1 is highly expressed, and MEK inhibition relieves feedback suppression of FGFR1, resulting in reactivation of ERK; suppression of ERK by MEKi/FGFRi combination results in tumor shrinkage. Cancer Discov; 6(7); 754–69. ©2016 AACR.

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Monday, June 27, 2016 2:02 PM|Barras, D., Missiaglia, E., Wirapati, P., Sieber, O. M., Jorissen, R. N., Love, C., Molloy, P. L., Jones, I. T., McLaughlin, S., Gibbs, P., Guinney, J., Simon, I. M., Roth, A., Bosman, F. T., Tejpar, S., Delorenzi, M.|Clinical Cancer Research Online First Articles|Labels: AKT, BRAF, EGFR, CRC

Purpose: Mutation of BRAF at the valine 600 residue occurs in ~10% of colorectal cancers (CRC), a group with particularly poor prognosis. The response of BRAF mutant CRC to recent targeted strategies such as anti-BRAF or combinations with MEK and EGFR inhibitors remains minimal and highly heterogeneous within BRAF V600E cohorts. There is clearly an unmet need in understanding the biology of BRAF V600E CRC and potential subgroups within this population. Experimental Design: In the biggest yet reported cohort of 218 BRAF V600E with gene expression data, we performed unsupervised clustering using non-negative matrix factorization to identify gene expression based subgroups and characterized pathway activation. Results: We found strong support for a split into two distinct groups, called BM1 and BM2. These subtypes are independent of MSI status, PI3K mutation, gender and sidedness. Pathway analyses revealed that BM1 is characterized by KRAS/AKT pathway activation, mTOR/4EBP deregulation and EMT while BM2 displays important deregulation of the cell cycle. Proteomics data validated these observations as BM1 is characterized by high phosphorylation levels of AKT and 4EBP1, and BM2 patients display high CDK1 and low cyclin D1 levels. We provide a global assessment of gene expression motifs that differentiate BRAF V600E subtypes from other CRC. Conclusions: We suggest that BRAF mutant patients should not be considered as having a unique biology and provide an in depth characterization of heterogeneous motifs that may be exploited for drug targeting.

Monday, June 27, 2016 12:52 PM|LUO, H., UMEBAYASHI, M., DOI, K., MORISAKI, T., SHIRASAWA, S., TSUNODA, T.|Anticancer Research recent issues|Labels: AKT, BRAF, melanoma, skin cancer

Background/Aim: The serine/threonine-protein kinase B-Raf (BRAF) V600E mutant (BRAFV600E) inhibitor vemurafenib, has improved clinical outcomes for patients with BRAFV600E melanoma, but acquired cellular resistance mediated by AKT serine/threonine kinase 1 (AKT) phosphorylation limits its efficacy. We examined the effect of resveratrol on vemurafenib-resistant melanoma cells. Materials and Methods: A vemurafenib-resistant human metastatic melanoma cell line positive for the BRAF V600E mutation was established. The anti-tumorigenic effects of vemurafenib and resveratrol, both alone and in combination, were examined through analysis of cell proliferation and protein expression. Results: The level of phosphorylated AKT (p-AKT) was increased in the primary melanoma cells after treatment with vemurafenib, and the basal level of p-AKT was increased in vemurafenib-resistant melanoma cells. Notably, resveratrol both alone and in combination with vemurafenib effectively suppressed cell proliferation and AKT phosphorylation in both parental and vemurafenib-resistant melanoma cells. Conclusion: Vemurafenib resistance can be reversed by addition of resveratrol in patients undergoing treatment with BRAF inhibitors.

Monday, June 27, 2016 12:52 PM|CHUNG, Y. H., KIM, D.|Anticancer Research recent issues|Labels: AKT, HDAC, NFKb, P-gp, CRC

Background: Phosphorylation of glycogen synthase kinase 3β (GSK3β) by phosphatidyl-inositide 3-kinase (PI3K)/protein kinase B (AKT) or inhibition of GSK3β with small-molecule inhibitor attenuates cell survival and proliferation and increases apoptosis in most cancer cell lines. In this study, we investigated the role of phosphorylated GSK3β activated by enhanced toll-like receptor 4 (TLR4) expression in drug-treated colon cancer cells as a model of post-chemotherapy cancer cells. Materials and Methods: The effect of TLR4 stimulation on metastasis and apoptosis in drug-exposed colon cancer cells was determined by real-time polymerase chain reaction (PCR) and immunoblotting. Results: Despite the induction of apoptosis after treatment with oxaliplatin and 5-fluorouracil, lipopolysaccharide (LPS) stimulation via increased TLR4 in drug-treated cancer cells effectively inhibited apoptosis through up-regulation of expression of anti-apoptosis-related B-cell lymphoma 2 (BCL2) family proteins [X-linked inhibitor of apoptosis protein (XIAP), BCL2, and survivin] and drug-resistance proteins [multidrug-resistance protein 1 (MDR1), multidrug resistance-associated protein (MRP)1/2/3]. LPS-mediated signaling in drug-treated cancer cells elevated the expression of phosphorylated GSK3β, extracellular signal–regulated kinase (ERK), and the p65 subunit of nuclear factor kappa-light-chain-enhancer of activated B-cells (NF-B). Pharmacological inhibition of GSK3β (using SB216763) reduced phosphorylation of GSK3β, re-activated caspase-dependent apoptosis, and blocked the expression of cancer stem cell markers and invasive characteristics in LPS-stimulated drug-treated cells. In addition, the ERK-specific inhibitor, PD98059, triggered the apoptosis of TLR4-activated drug-exposed colon cancer cells, whereas there was no effect on the expression of epithelial–mesenchymal transition markers or GSK3β phosphorylation. Conclusion: These results suggest that TLR4-induced GSK3β and ERK phosphorylation independently controls cancer cell survival and regulation of GSK3β and ERK after chemotherapy, making TLR4 a critical target for reducing drug resistance and metastasis in patients with colon cancer.

Friday, June 24, 2016 12:45 PM|Yang, Q., Chen, L. S., Ha, M. J., Do, K.-A., Neelapu, S. S., Gandhi, V.|Clinical Cancer Research Online First Articles|Labels: AKT, MapK, mTOR, lymphoma

Abstract Purpose: PI3 Kinase is a critical node in the B-cell receptor pathway which is responsible for survival and proliferation of B-cell malignancies. Idelalisib, a PI3K-isoform specific inhibitor, has been approved to treat B-cell malignancies. While biological activity of the drug has been evaluated, molecular mechanisms and signaling pathway disruption leading to the biological effects of idelalisib are not yet well-defined. Prior laboratory reports have identified transcription and translation as the primary events for attenuation of PI3Kα isoform. We hypothesized that PI3K-isoform inhibition by idelalisib should also affect gene transcription and protein translation. Experimental Design: Using three mantle cell lymphoma cell lines and primary cells from patients, biological consequences such as apoptosis/cell cycle analysis, as well as RNA/protein synthesis were evaluated. Proteomics analyses (RPPA and immunoblot assays) defined molecular events downstream of PI3K/AKT cassette. Results: Idelalisib treatment resulted in inhibition of protein synthesis, which correlated with reduction in cell size and cell growth. A moderate loss of viability without any change in cell cycle profile was observed. Idelalisib treatment inhibited AKT activation, an immediate downstream PI3K effector, and also reduced phosphorylation levels of downstream AKT/mTOR pathway proteins such as PRAS40. In addition, idelalisib treatment impeded activation of the MAPK pathway, and MEK, ERK and p90RSK phosphorylation levels were reduced. Reduction in AKT, PDK1, and MEK phosphorylation correlated with protein synthesis inhibition. Conclusions: Collectively, these results clarify the molecular mechanisms of actions and may provide biomarkers and targets for combination with idelalisib in B-cell malignancies.

Tuesday, June 21, 2016 9:14 AM|Stover, D. G., Coloff, J. L., Barry, W. T., Brugge, J. S., Winer, E. P., Selfors, L. M.|Clinical Cancer Research Online First Articles|Labels: AKT, EGFR, RAS, breast cancer

PURPOSE: To provide further insight into the role of proliferation and other cellular processes in chemosensitivity and resistance, we evaluated the association of a diverse set of gene expression signatures with response to neoadjuvant chemotherapy (NAC) in breast cancer. EXPERIMENTAL DESIGN: Expression data from primary breast cancer biopsies for 1419 patients in 17 studies prior to NAC were identified and aggregated using common normalization procedures. Clinicopathologic characteristics including response to NAC were collected. Scores for 125 previously published breast cancer-related gene expression signatures were calculated for each tumor. RESULTS: Within each receptor-based subgroup or PAM50 subtype, breast tumors with high proliferation signature scores were significantly more likely to achieve pCR to NAC. To distinguish 'proliferation-associated' from 'proliferation-independent' signatures, we used correlation and linear modeling approaches. Most signatures associated with response to NAC were proliferation-associated: 90.5% (38/42) in ER+/HER2- and 63.3% (38/60) in triple-negative breast cancer (TNBC). Proliferation-independent signatures predictive of response to NAC in ER+/HER2- breast cancer were related to immune activity, while those in TNBC comprised a diverse set of signatures, including immune, DNA damage, signaling pathways (PI3K, AKT, Ras, EGFR), and 'stemness' phenotypes. CONCLUSIONS: Proliferation differences account for the vast majority of predictive capacity of gene expression signatures in neoadjuvant chemosensitivity for ER+/HER2- breast cancers and, to a lesser extent, TNBCs. Immune activation signatures are proliferation-independent predictors of pCR in ER+/HER2- breast cancers. In TNBCs, significant proliferation-independent signatures include gene sets that represent a diverse set of cellular processes.-

Saturday, June 18, 2016 2:05 PM|Mario Campone; Olivier Tredan|JournalTOCs API - The Lancet Oncology (50 articles)|Labels: AKT, breast cancer

PI3K targeting in breast cancer: the end of the beginning'
Thomas Bachelot Mario Campone; Olivier Tredan
The Lancet Oncology, Vol. 17, No. 6 (2016) pp. 696 - 697
Publication date: June 2016 Source:The Lancet Oncology, Volume 17, Issue 6 Author(s): Thomas Bachelot, Mario Campone, Olivier Tredan

Thursday, June 16, 2016 12:05 AM|Raimo, M., Orso, F., Grassi, E., Cimino, D., Penna, E., De Pitta, C., Stadler, M. B., Primo, L., Calautti, E., Quaglino, P., Provero, P., Taverna, D.|Molecular Cancer Research recent issues|Labels: AKT, Notch, melanoma, skin cancer

Malignant melanoma is the most aggressive form of skin cancer; therefore, it is crucial to disclose its underlying molecular mechanisms. MicroRNAs (miRNAs) are small endogenous noncoding RNAs able to posttranscriptionally downregulate the expression of direct target genes. Using a melanoma progression model, miR-146a was identified as a key double-acting player in melanoma malignancy. In fact, miR-146a is able to enhance tumor growth, while it suppresses dissemination. It was determined that miR-146a coordinated melanoma cell growth by its direct targets lunatic fringe (LFNG) and NUMB, which operate on the NOTCH/PTEN/Akt pathway; while inhibition of metastasis formation was linked to decreased expression of ITGAV and ROCK1. Relevantly, miR-146a expression correlated with melanoma recurrence and was enriched in both patient-derived melanoma and cutaneous metastasis specimens, while its direct targets were depleted. However, miR-146a levels drop in circulating tumor cells (CTCs), suggesting the necessity for miR-146a expression to fluctuate during tumor progression in order to favor tumor growth and allow dissemination. This study reconciles the contradictory biologic functions of miR-146a in melanoma progression and unravels distinct molecular mechanisms that need to be considered for therapeutic interventions.

Implications: miR-146a controls melanoma progression in a dual way, promoting growth and inhibiting dissemination; however, it is poorly expressed in CTCs, resulting in overall tumor spreading and distant-site colonization. Mol Cancer Res; 14(6); 548–62. ©2016 AACR.

Wednesday, June 15, 2016 12:56 PM|Abdulghani, J., Gokare, P., Gallant, J.-N., Dicker, D. T., Whitcomb, T., Cooper, T. K., Liao, J., Derr, J., Liu, J., Goldenberg, D., Finnberg, N. K., El-Deiry, W. S.|Clinical Cancer Research Online First Articles|Labels: AKT, thymic

Purpose: Anaplastic thyroid cancer (ATC) comprises ~2% of all thyroid cancers and its median survival rate remains poor. It is responsible for more than one-third of thyroid cancer-related deaths. ATC is frequently resistant to conventional therapy and NFkappaB-signaling has been proposed to be a feature of the disease. We aimed to assess the activity of the anti-malaria drug quinacrine known to target NFkappaB-signaling in combination with the clinically relevant kinase inhibitor sorafenib in ATC cells. The presence of NFkappaB-p65/RelA and its target Mcl-1 was demonstrated in ATC by meta-data gene set enrichment analysis and immunohistochemistry (IHC). We assessed the responses of a panel of human ATC cell lines to quinacrine and sorafenib in vitro and in vivo. Results: We detected increased expression of NFkappaB-p65/RelA and Mcl-1 in the nucleus of a subset of ATC compared to non-neoplastic thyroid. ATC-cells were found to respond with additive/synergistic tumor cell-killing to the combination of sorafenib plus quinacrine in vitro and the drug combination improves survival of immunodeficient mice injected orthotopically with ATC-cells as compared to mice administered either compound alone or doxorubicin. We also demonstrate that the combination of sorafenib and quinacrine is well tolerated in mice. At the molecular level, quinacrine and sorafenib inhibited expression of the pro-survival gene Mcl-1, pStat3 and dampened NFkappaB signaling. Conclusion: The combination of quinacrine and sorafenib targets emerging molecular hallmarks of ATC and shows promising results in clinically relevant models for the disease. Further testing of sorafenib plus quinacrine can be conducted in ATC patients.

Wednesday, June 15, 2016 12:56 PM|Niessner, H., Schmitz, J., Tabatabai, G., Schmid, A., Calaminus, C., Sinnberg, T., Weide, B., Eigentler, T. K., Garbe, C., Schittek, B., Quintanilla-Fend, L., Bender, B., Mai, M., Praetorius, C., Beissert, S., Schackert, G., Muders, M., Meinhardt, M., Baretton, G. B., Dummer, R., Flaherty, K. T., Pichler, B. J., Kulms, D., Westphal, D., Meier, F.|Clinical Cancer Research Online First Articles|Labels: AKT, BRAF, melanoma, skin cancer

Purpose: Great advances have recently been made in treating patients with metastatic melanoma. However, existing therapies are less effective on cerebral than extracerebral metastases. This highlights the potential role of the brain environment on tumor progression and drug resistance and underlines the need for "brain-specific" therapies. We previously showed that the PI3K-AKT survival pathway is hyperactivated in brain but not extracerebral melanoma metastases and that astrocyte-conditioned medium activates AKT in melanoma cells in vitro. We therefore tested the PI3K inhibitor buparlisib as an antitumor agent for melanoma brain metastases. Experimental Design and Results: Buparlisib inhibited AKT activity, decreased proliferation and induced apoptosis in metastatic melanoma cell lines and short-term brain melanoma cells, irrespective of their BRAF and NRAS mutation status. Additionally, buparlisib inhibited hyperactivated AKT and induced apoptosis in melanoma cells that were stimulated with astrocyte-conditioned medium. The growth of tumors induced by injecting human BRAF- and NRAS-mutant metastatic melanoma cells into the brain of mice was significantly inhibited by buparlisib. Conclusions: These results emphasize the value of targeting the PI3K pathway as a strategy to develop drugs for melanoma brain metastases.

Thursday, June 9, 2016 3:06 AM|Press Releases | AbbVie Newsroom|Labels: AKT, Bcl-2

COPENHAGEN, Denmark, June 9, 2016 /PRNewswire/ -- AbbVie (NYSE: ABBV), a global biopharmaceutical company, will present data on its investigational medicine venetoclax, a B-cell lymphoma -2 (BCL-2) inhibitor, and duvelisib, an investigational phosphoinositide-3-kinase (PI3K)-delta and PI3K-gamma inhibitor, at the 21st European Hematology Association (EHA) Annual Congress, June 9-12, in Copenhagen, Denmark. Data will be presented in some of the most common hematological malignancies, including chronic lymphocytic leukemia (CLL), multiple myeloma (MM), acute myeloid leukemia (AML) and follicular lymphoma.

Tuesday, June 7, 2016 12:41 PM|Piro, G., Carbone, C., Cataldo, I., Di Nicolantonio, F., Giacopuzzi, S., Aprile, G., Simionato, F., Boschi, F., Zanotto, M., Mina, M. M., Santoro, R., Merz, V., Sbarbati, A., de Manzoni, G., Scarpa, A., Tortora, G., Melisi, D.|Clinical Cancer Research Online First Articles|Labels: AKT, EGFR, FGFR, FLT, gastric

Purpose: The majority of gastric cancer patients who achieve an initial response to trastuzumab-based regimens develop resistance within 1 year of treatment. This study was aimed at identifying the molecular mechanisms responsible for resistance. Experimental Design: A HER2+ trastuzumab sensitive NCI-N87 gastric cancer orthotopic nude mouse model was treated with trastuzumab until resistance emerged. Differentially expressed transcripts between trastuzumab-resistant and sensitive gastric cancer cell lines were annotated for functional interrelatedness by Ingenuity Pathway Analysis software. Immunohistochemical analyses were performed in pre- vs. post-treatment biopsies from gastric cancer patients receiving trastuzumab-based treatments. All statistical tests were two-sided. Results: Four NCI-N87 trastuzumab resistant (N87-TR) cell lines were established. Microarray analysis showed HER2 downregulation, induction of epithelial-to-mesenchymal transition, and indicated fibroblast growth factor receptor 3 (FGFR3) as one of the top upregulated genes in N87-TR cell lines. In vitro, N87-TR cell lines demonstrated a higher sensitivity than did trastuzumab-sensitive parental cells to the FGFR3 inhibitor dovitinib, which reduced expression of pAKT, ZEB1, and cell migration. Oral dovitinib significantly (P= 0.0006) reduced tumor burden and prolonged mice survival duration in N87-TR mouse models. A higher expression of FGFR3, phosphorylated AKT, and ZEB1 were observed in biopsies from patients progressing under trastuzumab-based therapies if compared with matched pre-treatment biopsies. Conclusions: This study identified the FGFR3/AKT axis as an escape pathway responsible for trastuzumab resistance in gastric cancer, thus indicating the inhibition of FGFR3 as a potential strategy to modulate this resistance.

Wednesday, May 18, 2016 5:00 PM|Cancer|Cancer via MedWorm.com|Comments|Labels: AKT, kidney cancer, clinical trial
CONCLUSIONSBuparlisib at a dose of 80 mg/day with bevacizumab was found to be a tolerable regimen with preliminary activity in vascular endothelial growth factor‐refractory mRCC. The benefit of this combination may be of interest for future mRCC trials, possibly in a selected patient population. Cancer 2016. © 2016 American Cancer Society. (Source: Cancer)
Tuesday, May 17, 2016 5:00 PM|Bioorganic and Medicinal Chemistry Letters|Bioorganic and Medicinal Chemistry Letters via MedWorm.com|Comments|Labels: AKT, VEGF, breast cancer, HL
Authors: Park EH, Park JY, Yoo HS, Yoo JE, Lee HL Abstract The anti-metastatic properties of sanguiin H-6 were examined in human umbilical vein vascular endothelial cells (HUVECs) and MDA-MB-231 human breast cancer cells. In HUVECs, sanguiin H-6 inhibited the density of migrated cells compared to that observed after treatment with the vehicle. In addition, sanguiin H-6 at a concentration of 6.25μM significantly blocked tube formation. Treatment with up to 25μM sanguiin H-6 had no effect on MDA-MB-231 cells, whereas treatment with 200μM sanguiin H-6 decreased cell viability. Sanguiin H-6 significantly decreased the expression levels of vascular endothelial growth factor (VEGF), phosphorylated Akt, and extracellular signal-regulated kinase 1/2 (ERK1/2) in MDA-MB-231 cells. These f...
Sunday, May 15, 2016 5:00 PM|Cancer|Cancer via MedWorm.com|Comments|Labels: AKT, leukemia
CONCLUSIONSPCTTOX is the major determinant of PFS in patients who receive first‐line idelalisib‐based treatment. However, a subgroup of patients with favorable biologic characteristics has prolonged PFS, even after PCTTOX. The absence of CLL‐related deaths indicates that salvage treatment is generally successful after PCTTOX. Cancer 2016;122:2505–11. © 2016 American Cancer Society. (Source: Cancer)
Thursday, April 28, 2016 4:15 PM|Mayer, I. A., Abramson, V., Formisano, L., Balko, J. M., Estrada, M. V., Sanders, M., Juric, D., Solit, D., Berger, M. F., Won, H., Li, Y., Cantley, L. C., Winer, E. P., Arteaga, C. L.|Clinical Cancer Research Online First Articles|Labels: AKT, breast cancer, clinical trial

Purpose:Alpelisib, a selective oral inhibitor of the class I PI3K catalytic subunit p110α, has shown synergistic anti-tumor activity with endocrine therapy against ER+/PIK3CA mutated breast cancer cells. This phase Ib study evaluated alpelisib plus letrozole's safety, tolerability and preliminary activity in patients with metastatic ER+ breast cancer refractory to endocrine therapy. Experimental Design:Twenty-six patients received letrozole and alpelisib daily. Outcomes were assessed by standard solid-tumor phase I methods. Tumor blocks were collected for DNA extraction and Next Generation Sequencing. Results:Alpelisib's maximum-tolerated dose (MTD) in combination with letrozole was 300 mg/d. Common drug-related adverse events included hyperglycemia, nausea, fatigue, diarrhea and rash with dose-limiting toxicity occurring at 350 mg/d of alpelisib. The clinical benefit rate (lack of progression {greater than or equal to}6 months) was 35% (44% in patients with PIK3CA mutated and 20% in PIK3CA wild-type tumors; 95% CI [17%; 56%]), including five objective responses. Of eight patients remaining on treatment {greater than or equal to}12 months, six had tumors with a PIK3CA mutation. Among evaluable tumors, those with FGFR1/2 amplification and KRAS and TP53 mutations did not derive clinical benefit. Overexpression of FGFR1 in ER+/PIK3CA mutant breast cancer cells attenuated the response to alpelisib in vitro. Conclusions:The combination of letrozole and alpelisib was safe, with reversible toxicities. Clinical activity was observed independently of PIK3CA mutation status although clinical benefit was seen in a higher proportion of patients with PIK3CA mutated tumors. Phase II and III trials of alpelisib and endocrine therapy in patients with ER+ breast cancer are ongoing.

Monday, March 28, 2016 2:24 PM|The Journal of Urology|MedWorm: Cancer Therapy|Comments|Labels: AKT, prostate cancer
We and others have demonstrated that the class IA PI3K isoform p110beta is critical in prostate cancer development and progression, indicating p110beta as a bona fide target for prostate cancer therapy. Our recent work consistently shows that prostate cancer cell-specific delivery of nano-micellar TGX221 completely blocked prostate cancer growth in vivo, suggesting that TGX221-based therapy is feasible for further development. Unfortunately, the small chemical TGX221 is not soluble in water, hampering its clinical development. (Source: The Journal of Urology)
Friday, March 25, 2016 12:33 PM|Oncotarget|MedWorm: Cancer Therapy|Comments|Labels: AKT, VEGF, gastric
In this study, we used adenoviral vector to deliver Bmi-1 shRNA driven by its own promoter to treat GC. Our results revealed that Ad-Bmi-1i could selectively silence Bmi-1 in GC cells which overexpress Bmi-1 and suppress the malignant phenotypes and stem-like properties of GC cells in vitro and in vivo. Moreover, direct injection of Ad-Bmi-1i into xenografts suppressed tumor growth and destroyed cancer cells in vivo. Ad-Bmi-1i inhibited the proliferation of GC cells mainly via inducing senescence in vitro, but it suppressed tumor through inducing senescence and apoptosis, and inhibiting angiogenesis in vivo. Bmi-1 knockdown by Ad-Bmi-1i downregulated VEGF via inhibiting AKT activity. These results suggest that Ad-Bmi-1i not only inhibits tumor growth and stem cell-like phenotype by inducin...
Thursday, March 24, 2016 6:00 PM|Current Pharmaceutical Design|Current Pharmaceutical Design via MedWorm.com|Comments|Labels: AKT, Bcr-Abl, HSP, P53, Src
Authors: Haque A, Alam Q, Alam MZ, Azhar EI, Sait KH, Anfina N, Mushtaq G, Kamal MA, Rasool M Abstract Heat Shock Protein 90 (HSP90) is a ubiquitous molecular chaperone that is considered to be the most abundantly expressed protein in various human cancers such as breast, lung, colon, prostate, leukemia and skin. The master regulator, HSP90 plays a pivotal role in the conformational stabilization, maturation and activity of its various labile oncogenic client proteins such as p53, ErbB2, Bcr-Abl, Akt, Her-2, Cdk4, Cdk6, Raf-1 and v-Src in altered cells. Hence, making a guaranteed attempt to inhibit such a master regulator for cancer therapy appears to be a potential approach for combinatorial inhibition of numerous oncogenic signaling pathways simultaneously. Considerable efforts a...
Tuesday, March 22, 2016 12:51 PM|Huang, X., Hwang, A., Sharma-Walia, N.|Journal of Investigative Medicine recent issues|Labels: AKT, P53, kaposi, lymphoma, clinical trial

Current treatments for Kaposi's Sarcoma (KS) and Primary Effusion Lymphoma (PEL) rely on systemic chemotherapeutics developed for non-virus-associated cancers that target DNA replication of all dividing cells. Other treatment methods aim at keeping immune system healthy and infection under control through surgery. All of the above approaches have low efficacy, high cost, and high risk of secondary malignancies especially in immuno-compromised patients. Hence, there is an emerging need to look for alternative treatment focused on KS or PEL host molecules, such as Lipoxins. Lipoxins are anti-inflammatory molecules that can target a variety of pro-inflammatory pathways of KS and PEL. Previous results from our lab have shown that level of ALX receptor (ALXR) does not change after Kaposi's Sarcoma Herpes Virus (KSHV) infection, leading to the potential use of Lipoxins to trigger anti-inflammatory and pro-apoptotic pathways as treatment of KS and PEL.

In this study, we investigated downstream signaling in KSHV harboring body cavity B cell lymphoma (BCBL-1) cells induced by Lipoxin treatment to assess its pro-apoptotic effect. We treated 5–10x106 BCBL-1 cells with solvent control (EtOH), Lipoxin (100 mM), or Epilipoxin (100 mM) for 48 and 72 hrs. Downstream phosphorylation of Akt, NF-kB p65, and ERK were assessed using Western blotting and pro-apoptotic gene changes were detected using Real-Time PCR. Cell survival and cell cycle progression was assessed using BrdU FACS analysis. We found that Lipoxin and Epilipoxin treatment downregulated NF-kB and ERK activation via ALXR binding while Akt signaling was not affected. We also found that Lipoxin successfully upregulated pro-apoptotic genes such as BIM-1, BAX, BCL-10, and p53 compared to control. Lipoxin treatment also led to decreased S-phase progression and induction of apoptosis. In conclusion, our study suggests that Lipoxins have therapeutic potential for PEL and should be explored in KS and other PEL cell types.

Thursday, March 17, 2016 7:00 PM|Cancer Cell|MedWorm: Cancer Therapy|Comments|Labels: AKT, liver cancer
Publication date: Available online 17 March 2016 Source:Cancer Cell Author(s): Qi Wang, Wan-Ni Yu, Xinyu Chen, Xiao-ding Peng, Sang-Min Jeon, Morris J. Birnbaum, Grace Guzman, Nissim Hay Akt is frequently hyperactivated in human cancers and is targeted for cancer therapy. However, the physiological consequences of systemic Akt isoform inhibition were not fully explored. We showed that while combined Akt1 and Akt3 deletion in adult mice is tolerated, combined Akt1 and Akt2 deletion induced rapid mortality. Akt2 −/− mice survived hepatic Akt1 deletion but all developed spontaneous hepatocellular carcinoma (HCC), which is associated with FoxO-dependent liver injury and inflammation. The gene expression signature of HCC-bearing livers is similar to aggressive human HCC. Consiste...
Wednesday, March 16, 2016 6:34 PM|Cellular Physiology and Biochemistry|MedWorm: Non-Small Cell Lung Cancer|Comments|Labels: AKT, lung cancer
Conclusion: In conclusion, periostin promotes CDDP resistance in NSCLC cells largely through activation of Stat3 and Akt and upregulation of survivin and thus represents a promising target for overcoming CDDP resistance.Cell Physiol Biochem 2016;38:1199-1208 (Source: Cellular Physiology and Biochemistry)
Tuesday, March 15, 2016 7:00 PM|Cancer Science|MedWorm: Non-Small Cell Lung Cancer|Comments|Labels: AKT, EGFR, lung cancer
The epidermal growth factor receptor (EGFR) tyrosine kinase signaling pathways regulate cellular activities. The EGFR tyrosine kinase inhibitors (EGFR‐TKIs) repress the EGFR pathway constitutively activated by somatic EGFR gene mutations and have drastically improved the prognosis of non‐small‐cell lung cancer (NSCLC) patients. However, some problems, including resistance, remain to be solved. Recently, combination therapy with EGFR‐TKIs and cytotoxic agents has been shown to improve the prognosis of NSCLC patients. To enhance the anticancer effects of EGFR‐TKIs, we examined the cross‐talk of the EGFR pathways with ataxia telangiectasia‐mutated (ATM) signaling pathways. ATM is a key protein kinase in the DNA damage response and is known to phosphorylate Akt, an EGFR downstrea...
Thursday, March 10, 2016 12:18 PM|Oncotarget|MedWorm: Non-Small Cell Lung Cancer|Comments|Labels: AKT, lung cancer
Authors: Zhang G, Wang C, Sun M, Li J, Wang B, Jin C, Hua P, Song G, Zhang Y, Nguyen LL, Cui R, Liu R, Wang L, Zhang X Abstract The cinobufagin (CB) has a broad spectrum of cytotoxicity to inhibit cell proliferation of various human cancer cell lines, but the molecular mechanisms still remain elusive. Here we observed that CB inhibited the cell proliferation and tumor growth, but induced cell cycle arrest and apoptosis in a dose-dependent manner in non-small cell lung cancer (NSCLC) cells. Treatment with CB significantly increased the reactive oxygen species but decreased the mitochondrial membrane potential in NSCLC cells. These effects were markedly blocked when the cells were pretreated with N-acetylcysteine, a specific reactive oxygen species inhibitor. Furthermore, treatment w...
Wednesday, March 9, 2016 6:00 PM|International Journal of Oncology|MedWorm: Non-Small Cell Lung Cancer|Comments|Labels: AKT, P53, lung cancer
Authors: In JK, Kim JK, Oh JS, Seo DW Abstract In the present study, we investigated the effects and molecular mechanism of 5-caffeoylquinic acid (5-CQA), a natural phenolic compound isolated from Ligularia fischeri, on cell invasion, proliferation and adhesion in p53 wild-type A549 and p53-deficient H1299 non-small cell lung cancer (NSCLC) cells. 5-CQA abrogated mitogen-stimulated invasion, but not proliferation, in both A549 and H1299 cells. In addition, 5-CQA inhibited mitogen-stimulated adhesion in A549 cells only. Anti-invasive activity of 5-CQA in A549 cells was mediated by the inactivation of p70S6K-dependent signaling pathway. In contrast, in H1299 cells the inactivation of Akt was found to be involved in 5-CQA-mediated inhibition of cell invasion. Collectively, these findi...
Sunday, March 6, 2016 6:00 PM|Acta Pharmacologica Sinica|MedWorm: Non-Small Cell Lung Cancer|Comments|Labels: AKT, lung cancer
CONCLUSION: Hyperoside induces both autophagy and apoptosis in human non-small cell lung cancer cells in vitro. The autophagy is induced through inhibiting the Akt/mTOR/p70S6K signal pathways, which contributes to anticancer actions of hyperoside. PMID: 26948085 [PubMed - as supplied by publisher] (Source: Acta Pharmacologica Sinica)
Wednesday, March 2, 2016 6:00 PM|Cancer Immunology, Immunotherapy|MedWorm: Non-Small Cell Lung Cancer|Comments|Labels: AKT, lung cancer
Abstract MHC class I chain-related molecule A and B (MICA/B) are NK group 2 member D (NKG2D) ligands, which are broadly expressed in transformed cells. Both DNA damage-induced ataxia-telangiectasia-mutated (ATM)- and ATM and Rad3-related protein kinases (ATM–ATR) signaling and oncogene-induced PI3K–AKT signaling regulate the expression of NKG2D ligands, which promote NK cell-mediated cytotoxicity via NKG2D–NKG2D ligand interactions. NKG2D ligand overexpression was recently reported to be correlated with good prognosis in several types of cancer. However, the prognostic significance of NKG2D ligands in non-small cell lung cancer (NSCLC) remains unclear. Here, MICA/B expression was evaluated based on immunohistochemistry of 91 NSCLC samples from patients following radical sur...
Monday, February 29, 2016 6:00 PM|Journal of Cellular and Molecular Medicine|MedWorm: Non-Small Cell Lung Cancer|Comments|Labels: AKT, lung cancer
This study aimed at investigating potential mechanisms of CCL20 function and production in human non‐small cell lung cancer (NSCLC). Expression of CCL20 gene and protein in lung tissues of patients with NSCLC and NSCLC cells (A549) were determined. The interleukin (IL)‐1β‐induced signal pathways in A549 and the effect of CCL20‐induced A549 cell migration and proliferation were determined using migration assays and cell‐alive monitoring system. Mechanisms of signal pathways involved in the migration of CCL20 were also studied. We initially found that NSCLC tumour tissues markedly overexpressed CCL20 in comparison with normal lung samples. In addition, IL‐1β could directly promote CCL20 production in lung cancer cells, which was inhibited by extracellular signal‐regulated kin...

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Friday, February 26, 2016 6:00 AM|Society for Endocrinology|MedWorm: Non-Small Cell Lung Cancer|Comments|Labels: AKT, BRAF, HSP, MapK, mTOR, thymic
~Dose-limiting toxicity has restricted the use of kinase inhibitors in differentiated thyroid cancer. Gild et al. have taken advantage of the role of the heat shock protein HSP90 in mediating the effect of kinases such as RET, AKT and BRAF to investigate an alternative mechanism to downregulate these pathways. HSP90 regulates protein degradation of these kinases, and is overexpressed in cancer cells. The action of an HSP90 inhibitor AUY922 against medullary and papillary thyroid cancer (PTC) cell lines expressing a RET mutation was studied in vitro. AUY922 inhibited MAPK and mTOR signalling and induced apoptosis in vitro, and enhanced radioactive iodine uptake in the PTC cell line. The latter effect is particularly significant given the reduced iodine avidity of such tumours clinically. AU...
Tuesday, February 23, 2016 6:00 PM|Biochemical Pharmacology|MedWorm: Non-Small Cell Lung Cancer|Comments|Labels: AKT, lung cancer
In conclusion, astaxanthin enhances MMC-induced cytotoxicity by decreasing Rad51 expression and AKT activation. These findings may provide rationale to combine astaxanthin with MMC for the treatment of NSCLC. PMID: 26921637 [PubMed - as supplied by publisher] (Source: Biochemical Pharmacology)
Wednesday, February 17, 2016 9:28 AM|Cancer Investigation|MedWorm: Non-Small Cell Lung Cancer|Comments|Labels: AKT, lung cancer
This study demonstrated that miR-21 and miR-95 expression were significantly higher in the ALDH1(+)CD133(+)subpopulation than in the ALDH1(-)CD133(-) subpopulation of lung cancer cells. Combined delivery of anti-miR-21 and anti-miR-95 by calcium phosphate nanoparticles significantly inhibited tumor growth in a xenograft tumor model and sensitized radiotherapy. The anti-miRNAs significantly reduced miR-21 and miR-95 levels, increased PTEN, SNX1, and SGPP1 protein expression, but reduced Akt Ser(473) and Thr(308) phosphorylation. ALDH1(+)CD133(+) subpopulation of NSCLC tumor cells confers radioresistance due to high expression of miR-21 and miR-95. Targeting inhibition of miR-21 and miR-95 can inhibit tumor growth through elevating PTEN, SNX1, and SGPP1 expression and inhibiting Akt phosphor...
Wednesday, February 10, 2016 1:19 PM|Molecular Carcinogenesis|MedWorm: Non-Small Cell Lung Cancer|Comments|Labels: AKT, NFKb, lung cancer
In conclusion, Icariside II might prohibit invasion through inactivating Akt/NF‐κB pathway. © 2016 Wiley Periodicals, Inc. (Source: Molecular Carcinogenesis)

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Sunday, January 24, 2016 7:10 AM|Oncology Research|MedWorm: Non-Small Cell Lung Cancer|Comments|Labels: AKT, lung cancer
In this study, downregulated PDCD4 mRNA expression was found in NSCLC tissues compared to their corresponding paracarcinoma tissues and distal paracarcinoma tissues. Induced expression of PDCD4 inhibited cell growth and proliferation and cell cycle transition in vitro. Conversely, knocking down PDCD4 expression promoted cell growth and proliferation. Mechanistically, PDCD4 inactivated PI3K/Akt signaling and its downstream cell cycle factors CCND1 and CDK4 to regulate cell growth in NSCLC. Additionally, PI3K-specific inhibitor Ly294002 suppressed the expression of pPI3K (Tyr458), pAkt (Ser473), CCND1, and CDK4 in PC9-shPDCD4 and A549-shPDCD4 cells. Furthermore, Akt-specific inhibitor MK2206 inhibited the expression of pAkt (Ser473), CCND1, and CDK4 in PC9-shPDCD4 and A549-shPDCD4 cells. Tak...

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Tuesday, January 19, 2016 11:00 PM|Chinese Journal of Lung Cancer|MedWorm: Non-Small Cell Lung Cancer|Comments|Labels: AKT, EGFR, lung cancer
Conclusion TRIM24 could regulate required resistance to Gefitinib via Akt pathway in NSCLC. DOI: 10.3779/j.issn.1009-3419.2016.01.03 (Source: Chinese Journal of Lung Cancer)
Sunday, January 17, 2016 6:00 PM|BJU International|MedWorm: Transitional Cell Carcinoma|Comments|Labels: AKT, mTOR, kidney cancer
ConclusionsBEZ235 showed modest clinical activity and an unfavorable toxicity in patients with advanced and pretreated TCC. However, a minority of patients presented clinical benefit, suggesting that a complete blockade of the PI3K/ mTOR axis could improve outcome in some specific patients. Furthermore, this study showed that molecular stratification of patients for personalized medicine before treatment is feasible.This article is protected by copyright. All rights reserved. (Source: BJU International)
Saturday, January 16, 2016 12:54 PM|Molecular Medicine Reports|MedWorm: Transitional Cell Carcinoma|Comments|Labels: AKT, bladder cancer
Authors: Zheng SS, Gao JG, Liu ZJ, Zhang XH, Wu S, Weng BW, Wang YL, Hou SC, Jiang B Abstract The aim of the present study was to investigate the effect of fatty acid synthase complex (FASN) on the migration capacity of bladder transitional cell carcinoma (BTCC) cells and the involvement of matrix metalloproteinase‑9 (MMP‑9) via targeting of phospho‑AKT (p‑AKT). FASN‑specific small‑interfering RNA (FASN‑siRNA) was used to inhibit FASN gene expression in the 5637 and 253J BTCC cell lines. The knockdown efficiency of FAM‑conjugated FASN‑siRNA was confirmed by fluorescence microscopy. The migratory abilities of BTCC cells were assessed using a Transwell assay. Furthermore, protein and mRNA expression of FASN, p‑AKT, AKT, and migration‑associated protein MMP‑9 w...
Thursday, January 14, 2016 6:00 PM|Molecular Cancer Research|MedWorm: Cancer Therapy|Comments|Labels: AKT, mTOR, brain cancer
Aerobic glycolysis (the Warburg effect), first recognized almost a century ago, by Otto Warburg is a core hallmark of cancer. The Warburg effect describes a switch in glucose metabolism from oxidative phosphorylation to glycolysis. Recently links have been established between the oncogenic pathways that drive tumorigenesis and the mechanistic basis of tumor cell metabolism. The kinase mTOR is a major driver of tumor metabolism and proliferation of cancer cells, acts downstream of numerous oncogenic pathways. Several drugs targeting the mTOR pathway are being developed, however the most common drug rapamycin does not inhibit mTOR complex-2. Therefore in the current study, we examined the potential benefit of MLN0128, a novel potent mTOR ATP competitive inhibitor, as a therapeutic strategy f...
Thursday, January 14, 2016 6:00 PM|Molecular Cancer Research|MedWorm: Cancer Therapy|Comments|Labels: AKT, ROS
I will describe two approaches for cancer therapy, which exploit distinct intracellular metabolism in cancer cells to selectively eradicate them. In the first part of my presentation I will describe how we could target hexokinase 2 for cancer therapy, and without any overt physiological consequences. In the second part of the presentation I will describe how we could exploit high levels of reactive oxygen species (ROS) in cancer cells displaying hyperactive Akt to selectively eradicate these cancer cells and to evade chemoresistance induced by hyperactivation of Akt.Hexokinases, which catalyze the first committed step in glucose metabolism, play a vital role in the cellular uptake and utilization of glucose. By catalyzing the ATP-dependent phosphorylation of glucose to yield glucose 6-phos...
Wednesday, January 13, 2016 6:00 PM|Cancer Research|MedWorm: Non-Small Cell Lung Cancer|Comments|Labels: AKT, EGFR, mTOR, lung cancer
Alterations in EGFR, KRAS, and ALK are oncogenic drivers in lung cancer, but how oncogenic signaling influences immunity in the tumor microenvironment is just beginning to be understood. Immunosuppression likely contributes to lung cancer, because drugs that inhibit immune checkpoints like PD-1 and PD-L1 have clinical benefit. Here, we show that activation of the AKT–mTOR pathway tightly regulates PD-L1 expression in vitro and in vivo. Both oncogenic and IFNγ-mediated induction of PD-L1 was dependent on mTOR. In human lung adenocarcinomas and squamous cell carcinomas, membranous expression of PD-L1 was significantly associated with mTOR activation. These data suggest that oncogenic activation of the AKT–mTOR pathway promotes immune escape by driving expression of PD-L1, which was conf...
Monday, January 11, 2016 6:00 PM|European Journal of Medicinal Chemistry|MedWorm: Cancer Therapy|Comments|Labels: AKT, mTOR, RAS
Authors: Asati V, Mahapatra DK, Bharti SK Abstract The protein kinases regulate cellular functions such as transcription, translation, proliferation, growth and survival by the process of phosphorylation. Over activation of signaling pathways play a major role in oncogenesis. The PI3K signaling pathway is dysregulated almost in all cancers due to the amplification, genetic mutation of PI3K gene and the components of the PI3K pathway themselves. Stimulation of the PI3K/Akt/mTOR and Ras/Raf/MEK/ERK pathways enhances growth, survival, and metabolism of cancer cells. Recently, the PI3K/Akt/mTOR and Ras/Raf/MEK/ERK signaling pathways have been identified as promising therapeutic targets for cancer therapy. The kinase inhibitors with enhanced specificity and improved pharmacokinetics hav...
Wednesday, January 6, 2016 6:00 PM|Molecular Cancer Therapeutics|MedWorm: Non-Small Cell Lung Cancer|Comments|Labels: AKT, EGFR, lung cancer
Conclusion:These results highlight that cells could acquire drug resistance through a bioenergetics switch from mitochondrial respiration to glycolysis.Citation Format: Bhaskar Bhattacharya, King Xin Koh, Mohamed Feroz Mohamed Omar, Sarah Low, Juleen Tan, Nur Sabrina Sapari, Barry Iacopetta, Ross Soo, Mounia Beloueche-Babari, Richie Soong. Bioenergetic switch confers acquired resistance to BEZ235 in EGFR T790M-mutant non-small cell lung cancer. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr B52. (Source: Molecular Cancer Therapeutics)

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Wednesday, January 6, 2016 6:00 PM|Molecular Cancer Therapeutics|MedWorm: Non-Small Cell Lung Cancer|Comments|Labels: AKT, HSP, lung cancer
Conclusion: The dual inhibition of HSP90 and MEK signaling pathways on sub-effective dose may constitute a potent therapeutic strategy to treat intrinsic MEK inhibitor resistant G13DKRAS mutant NSCLCs for resolving toxicity problem of dual inhibition of AKT and MEK in clinical trials.Citation Format: Dae Ho Lee, Kang-Seo Park, Bora Oh, Mi-Hee Lee, Hannah Yang. HSP90 inhibitor NVP-AUY922 sensitizes intrinsic MEK inhibitor Trametinib-resistant NSCLC cells harboring KRAS mutation. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr B90. (Source: Molecular Cancer Therapeutics)
Wednesday, January 6, 2016 6:00 PM|Molecular Cancer Therapeutics|MedWorm: Non-Small Cell Lung Cancer|Comments|Labels: AKT, EGFR, FGFR, mTOR, kidney cancer
Conclusion: These results suggest that ibrutinib, a kinase inhibitor with immune modulatory properties, has anti-tumor activity against RCC when combined with mTOR inhibitors or pazopanib with different target spectrums. Although EGFR is not critical for proliferation in these untreated RCC lines, ibrutinib may prevent ErbB kinases from contributing to feedback up-regulation of Akt/Erk pathways by established drugs. These results provide a preclinical rationale for investigation of ibrutinib as a novel agent for RCC through positive interaction with mTOR inhibitors and/or pazopanib.Citation Format: Jun Chen, Jeff Hsu, Yujun Huang, Danelle F. James, Taisei Kinoshita, Betty Y. Chang. Ibrutinib potentiates the effects of mTOR inhibitors and pazopanib in renal cell carcinoma in vitro and in vi...
Wednesday, January 6, 2016 6:00 PM|Molecular Cancer Therapeutics|MedWorm: Cancer Therapy|Comments|Labels: AKT, mTOR, breast cancer
AIM: The aim of this study was to identify markers that have the potential to predict BKM120 (a pan-class I PI3K inhibitor) effectiveness in triple negative breast cancer.INTRODUCTION: Triple negative breast cancer is an aggressive subtype that constitutes circa 20% of all breast cancers. This subtype of breast cancer is defined by its lack of estrogen-, progesterone- and HER2/neu expression. Since these are the operative receptors for targeted breast cancer therapies, current standard treatment instead centers on conventional cytotoxic chemotherapy. Unfortunately, the majority of triple negative breast cancer patients does not have meaningful response, and new therapeutic agents are needed. The PI3K/Akt/mTOR axis is often dysregulated in breast cancer, and clinical trials are ongoing for ...
Thursday, October 1, 2015 1:00 AM|Zhou, Xiang; Xu, Chang-Juan; Wang, Jun-Xian; Dai, Ting; Ye, Ya-Ping; Cui, Yan-Mei; Liao, Wen-Ting; Wu, Xin-Lin; Ou, Jian-Ping|International Journal of Gynecological Cancer - Most Popular Articles|Labels: AKT, cervical cancer
imageObjective: The aim of this study is to investigate the clinicopathologic significance and potential role of metastasis-associated in colon cancer-1 (MACC1) in the progression of cervical cancer. Methods: MACC1 expression was examined in cervical cancer cell lines, 6 matched cervical cancer tissues, and adjacent noncancerous tissues using Western blotting and real-time reverse transcriptase polymerase chain reaction. MACC1 protein expression and localization were determined in 181 paraffin-embedded archived cervical cancer samples using immunohistochemistry. Statistical analyses were applied to evaluate the clinicopathologic significance. The effects of MACC1 on cell migration, invasion, and angiogenesis were examined using migration assay, wound healing assay, 3-dimensional morphogenesis assay, and chicken chorioallantoic membrane assay. Western blotting was performed to examine the impact of MACC1 on the Akt and nuclear factor κB signaling pathways. Results: Both protein and messenger RNA levels of MACC1 was up-regulated in cervical cancer cell lines and cervical cancer tissues, as compared with normal tissues. High MACC1 expression was detected in 96 (53%) of 181 of the cervical cancer tissues. In addition, high MACC1 expression correlated significantly with aggressiveness of cervical cancer, including International Federation of Gynecology and Obstetric stage (P = 0.001), pelvic lymph node metastasis (P = 0.004), recurrence (P = 0.037), and poor survival (P = 0.001). Moreover, enforced expression of MACC1 in cervical cancer cell lines significantly enhanced cell migration, invasion, and angiogenesis. Conversely, knockdown of MACC1 caused an inhibition of cell migration, invasion, and angiogenesis. Up-regulation of MACC1 increased, but knockdown of MACC1 decreased the expression of matrix metalloproteinase-2 and matrix metalloproteinase-9. Furthermore, enforced expression of MACC1 could enhance, but knockdown of MACC1 could reduce AKT and nuclear factor κB pathway activity. Conclusions: Our findings suggest that MACC1 protein, as a valuable marker of cervical cancer prognosis, plays an important role in the progression of human cervical cancer cells.