mk-2206 and Neoplasms

Given the evidence that coordinate inhibition of AKT induces autophagy, we studied the combination of the AKT inhibitor, MK-2206 with hydroxychloroquine (HCQ) in patients with advanced solid tumors.. Patients were treated with weekly MK-2206 (135 mg or 200 mg) plus HCQ (200 mg, 400 mg or 600 mg BID).. Thirty-five patients were enrolled across 5 dose levels. Two DLTs of grade 3 maculo-papular rash were observed at dose level 2 (MK-2206 200 mg weekly plus HCQ at 400 mg BID) and 1 DLT of grade 3 fatigue at dose level 2B (MK-2206 135 mg weekly plus HCQ 600 mg BID). The maximum tolerated dose (MTD) was declared as dose level 2B. The most common adverse events attributed to MK-2206 were hyperglycemia (N = 18; 51%), fatigue (N = 17; 49%), maculo-papular rash (N = 16; 46%), diarrhea (N = 12; 34%), anorexia (N = 11; 31%), and nausea (N = 11; 31%). Patients experiencing adverse events attributed to HCQ were small in number (N = 13) and primarily included fatigue (N = 5; 14%) and maculo-papular rashes (N = 3; 9%). Statistically significant effects on the pharmacokinetic properties of MK-2206 were observed in combination with HCQ. In addition, the plasma concentrations of HCQ in the combination with MK-2206 were significantly higher than the plasma levels of HCQ as monotherapy in prior studies. The best overall response of stable disease was observed in 5/34 (15%) patients.. The combination of MK-2206 and hydroxychloroquine was tolerable, but with substantial number of drug-related AEs and minimal evidence of antitumor activity.

Topics: Antineoplastic Combined Chemotherapy Protocols; Autophagy; Dose-Response Relationship, Drug; Drug Monitoring; Drug-Related Side Effects and Adverse Reactions; Enzyme Inhibitors; Female; Heterocyclic Compounds, 3-Ring; Humans; Hydroxychloroquine; Male; Maximum Tolerated Dose; Middle Aged; Neoplasm Staging; Neoplasms; Phosphatidylinositol 3-Kinases; Protein Serine-Threonine Kinases

KRAS is the most commonly mutated oncogene in human tumors. KRAS-mutant cells may exhibit resistance to the allosteric MEK1/2 inhibitor selumetinib (AZD6244; ARRY-142886) and allosteric AKT inhibitors (such as MK-2206), the combination of which may overcome resistance to both monotherapies.. We conducted a dose/schedule-finding study evaluating MK-2206 and selumetinib in patients with advanced treatment-refractory solid tumors. Recommended dosing schedules were defined as MK-2206 at 135 mg weekly and selumetinib at 100 mg once daily.. Grade 3 rash was the most common dose-limiting toxicity (DLT); other DLTs included grade 4 lipase increase, grade 3 stomatitis, diarrhea, and fatigue, and grade 3 and grade 2 retinal pigment epithelium detachment. There were no meaningful pharmacokinetic drug-drug interactions. Clinical antitumor activity included RECIST 1.0-confirmed partial responses in non-small cell lung cancer and low-grade ovarian carcinoma.. Responses in KRAS-mutant cancers were generally durable. Clinical cotargeting of MEK and AKT signaling may be an important therapeutic strategy in KRAS-driven human malignancies (Trial NCT number NCT01021748).

Topics: Adult; Aged; Aged, 80 and over; Animals; Antineoplastic Combined Chemotherapy Protocols; Benzimidazoles; Cell Line, Tumor; Female; Heterocyclic Compounds, 3-Ring; Humans; Male; MAP Kinase Kinase Kinases; Mice; Middle Aged; Neoplasms; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-akt; Proto-Oncogene Proteins p21(ras); ras Proteins; Xenograft Model Antitumor Assays

There is preclinical synergism between taxanes and MK-2206. We aim to determine the maximum tolerated dose, safety, and activity of combining MK-2206 and paclitaxel in metastatic cancer.. Patients received weekly doses of paclitaxel at 80mg/m2 on day 1, followed by MK-2206 orally on day 2 escalated at 90mg, 135mg, and 200mg. Treatment continued until progression, excessive toxicity, or patient request. Blood and tissue were collected for pharmacokinetic and pharmacodynamics markers. A cycle consisted of three weeks of therapy. Dose-limiting toxicity (DLT) was defined as unacceptable toxicity during the first cycle. All statistical tests were two-sided.. Twenty-two patients were treated, nine in dose escalation and 13 in dose expansion. Median age was 55 years. Median number of cycles was four. Dose escalation was completed with no DLT. CTCAE Grade 3 or higher adverse events were fatigue (n = 2), rash (n = 2), hyperglycemia (n = 1), and neutropenia (n = 7). Four patients in the expansion phase required MK-2206 dose reduction. Phase II recommended dose was established as paclitaxel 80mg/m2 weekly on day 1, and MK-2206 135mg weekly on day 2. Paclitaxel systemic exposure was similar in the presence or absence of MK-2206. Plasma MK-2206 concentrations were similar to data from previous phase I monotherapy. There was a statistically significant decrease in expression of pAKT S473 (P = .01) and pAKT T308 (P = .002) after therapy. PI3K/AKT/mTOR downregulation in tumor tissues and circulating markers did not correlate with tumor response or clinical benefit. There were five objective responses, and nine patients had stable disease.. MK-2206 was well tolerated with paclitaxel. Preliminary antitumor activity was documented.

Topics: Adult; Aged; Antineoplastic Combined Chemotherapy Protocols; Biomarkers, Tumor; Breast Neoplasms; Drug Administration Schedule; Drug Eruptions; Fatigue; Female; Heterocyclic Compounds, 3-Ring; Humans; Hyperglycemia; Male; Maximum Tolerated Dose; Middle Aged; Neoplasms; Neutropenia; Paclitaxel; Severity of Illness Index; Treatment Outcome

The PI3K/Akt/mTOR signaling pathway is aberrantly activated in many cancers. Combining ridaforolimus, an mTOR inhibitor, with MK-2206, an Akt inhibitor, may more completely block the PI3K pathway and inhibit tumor growth.. This phase I study assessed dose-limiting toxicities (DLT) and maximum tolerated dose (MTD) for the combination of oral ridaforolimus plus oral MK-2206 in patients with advanced solid tumors. Efficacy was evaluated in patients with biomarker-identified estrogen receptor-positive breast cancer (low RAS gene signature and high Ki67 index) or castration-resistant prostate cancer (PTEN deficiency) with PI3K pathway addiction.. Thirty-five patients were enrolled: 11 patients in part A (three breast cancer) and 24 biomarker-eligible patients in part B (16 breast cancer, eight prostate cancer). One patient with breast cancer from part A was also found to be biomarker-eligible when tested after she had clinical response. The MTD was 10 mg/d ridaforolimus 5 d/wk + 90 mg/wk MK-2206; 1 of 17 patients experienced DLT (grade 3 rash) at this dose. The most common adverse events at MTD were rash (44.4%), stomatitis (38.9%), diarrhea (27.8%), and decreased appetite (27.8%). By investigator assessment, 2 of 16 (12.5%) evaluable patients with breast cancer had partial response; by central assessment, 2 of 14 (14.3%) evaluable patients had complete response. Two patients had durable stable disease (SD) for 416 and 285 days, respectively. No patients with prostate cancer responded; one patient had SD for ≥ 6 months.. Combination ridaforolimus and MK-2206 showed promising activity and good tolerability in heavily pretreated patients with hormone-positive and -negative breast cancer exhibiting PI3K pathway dependence.

Topics: Adult; Aged; Aged, 80 and over; Antineoplastic Combined Chemotherapy Protocols; Biomarkers; Female; Heterocyclic Compounds, 3-Ring; Humans; Male; Middle Aged; Neoplasm Staging; Neoplasms; Phosphoinositide-3 Kinase Inhibitors; Protein Kinase Inhibitors; Retreatment; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases; Treatment Outcome; Young Adult

AKT1(E17K) mutations occur at low frequency in a variety of solid tumors, including those of the breast and urinary bladder. Although this mutation has been shown to transform rodent cells in culture, it was found to be less oncogenic than PIK3CA mutations in breast epithelial cells. Moreover, the therapeutic potential of AKT inhibitors in human tumors with an endogenous AKT1(E17K) mutation is not known. Expression of exogenous copies of AKT1(E17K) in MCF10A breast epithelial cells increased phosphorylation of AKT and its substrates, induced colony formation in soft agar, and formation of lesions in the mammary fat pad of immunodeficient mice. These effects were inhibited by the allosteric and catalytic AKT inhibitors MK-2206 and AZD5363, respectively. Both AKT inhibitors caused highly significant growth inhibition of breast cancer explant models with AKT1(E17K) mutation. Furthermore, in a phase I clinical study, the catalytic Akt inhibitor AZD5363 induced partial responses in patients with breast and ovarian cancer with tumors containing AKT1(E17K) mutations. In MGH-U3 bladder cancer xenografts, which contain both AKT1(E17K) and FGFR3(Y373C) mutations, AZD5363 monotherapy did not significantly reduce tumor growth, but tumor regression was observed in combination with the FGFR inhibitor AZD4547. The data show that tumors with AKT1(E17K) mutations are rational therapeutic targets for AKT inhibitors, although combinations with other targeted agents may be required where activating oncogenic mutations of other proteins are present in the same tumor.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Blotting, Western; Cell Line; Cell Line, Tumor; Cell Proliferation; Doxycycline; Female; Heterocyclic Compounds, 3-Ring; Humans; Male; Mice, Nude; Mutation, Missense; Neoplasms; Phosphorylation; Proto-Oncogene Proteins c-akt; Pyrimidines; Pyrroles; Signal Transduction; Xenograft Model Antitumor Assays

Inhibition of AKT with MK-2206 has demonstrated synergism with anticancer agents. This phase 1 study assessed the MTD, DLTs, PK, and efficacy of MK-2206 in combination with cytotoxic and targeted therapies.. Advanced solid tumor patients received oral MK-2206 45 or 60 mg (QOD) with either carboplatin (AUC 6.0) and paclitaxel 200 mg/m2 (arm 1), docetaxel 75 mg/m2 (arm 2), or erlotinib 100 or 150 mg daily (arm 3); alternative schedules of MK-2206 135-200 mg QW or 90-250 mg Q3W were also tested.. MTD of MK-2206 (N = 72) was 45 mg QOD or 200 mg Q3W (arm 1); MAD was 200 mg Q3W (arm 2) and 135 mg QW (arm 3). DLTs included skin rash (arms 1, 3), febrile neutropenia (QOD, arms 1, 2), tinnitus (Q3W, arm 2), and stomatitis (QOD, arm 3). Common drug-related toxicities included fatigue (68%), nausea (49%), and rash (47%). Two patients with squamous cell carcinoma of the head and neck (arm 1; Q3W) demonstrated a complete and partial response (PR); additional PRs were observed in patients (1 each) with melanoma, endometrial, neuroendocrine prostate, NSCLC, and cervical cancers. Six patients had stable disease ≥6 months.. MK-2206 plus carboplatin and paclitaxel, docetaxel, or erlotinib was well-tolerated, with early evidence of antitumor activity.

Topics: Administration, Oral; Adult; Aged; Antineoplastic Combined Chemotherapy Protocols; Area Under Curve; Carboplatin; Docetaxel; Dose-Response Relationship, Drug; Erlotinib Hydrochloride; Exanthema; Fatigue; Febrile Neutropenia; Female; Heterocyclic Compounds, 3-Ring; Humans; Male; Middle Aged; Nausea; Neoplasms; Paclitaxel; Proto-Oncogene Proteins c-akt; Quinazolines; Stomatitis; Taxoids; Tinnitus; Treatment Outcome; Young Adult

We report results of a phase I trial designed to estimate the maximum tolerated dose (MTD), describe dose-limiting toxicities (DLT), and characterize the pharmacokinetic profile of MK-2206, an AKT inhibitor, in children with refractory or recurrent malignancies.. MK-2206 was administered either every other day (Schedule 1), or once a week (Schedule 2) in a 28-day cycle. Dose escalations in increments of ∼30% were independently made in each part using the rolling-six design. Serial pharmacokinetic (PK) studies were obtained. Biological studies include analysis of PI3K/PTEN/AKT-cell signaling pathway in pre and post-therapy in PBMC and in tumors at diagnosis or recurrence.. Fifty patients (26 males, median age 12.6 years [range, 3.1-21.9]) with malignant glioma (16), ependymoma (4), hepatocellular carcinoma (3), gliomatosis cereberi (2), or other tumors (22) were enrolled; 40 were fully evaluable for toxicity (Schedule 1, n = 23; Schedule 2, n = 17). Schedule 1 DLTs included: grade 3 dehydration in 1/6 patients at 28 mg/m(2) ; grade 4 hyperglycemia and neutropenia in 1/6 patients at 45 mg/m(2) ; and grade 3 rash in 3/6 patients at dose level 4 (58 mg/m(2) ). Schedule 2 DLTs included: grade 3 alkaline phosphatase in 1/6 patients at 90 mg/m(2) ; grade 3 rash in 1/6 patients at 120 mg/m(2) ; and grade 3 rash in 2/6 patients at 155 mg/m(2) .. The recommended pediatric phase 2 dose of MK-2206 is 45 mg/m(2) /dose every other day or 120 mg/m(2) /dose weekly. PK appeared linear over the dose range studied.

Topics: Adolescent; Adult; Child; Child, Preschool; Heterocyclic Compounds, 3-Ring; Humans; Infant; Maximum Tolerated Dose; Neoplasms; Phosphatidylinositol 3-Kinases; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-akt; PTEN Phosphohydrolase

Multiple cancers harbor genetic aberrations that impact AKT signaling. MK-2206 is a potent pan-AKT inhibitor with a maximum tolerated dose (MTD) previously established at 60 mg on alternate days (QOD). Due to a long half-life (60-80 hours), a weekly (QW) MK-2206 schedule was pursued to compare intermittent QW and continuous QOD dosing.. Patients with advanced cancers were enrolled in a QW dose-escalation phase I study to investigate the safety and pharmacokinetic-pharmacodynamic profiles of tumor and platelet-rich plasma (PRP). The QOD MTD of MK-2206 was also assessed in patients with ovarian and castration-resistant prostate cancers and patients with advanced cancers undergoing multiparametric functional magnetic resonance imaging (MRI) studies, including dynamic contrast-enhanced MRI, diffusion-weighted imaging, magnetic resonance spectroscopy, and intrinsic susceptibility-weighted MRI.. A total of 71 patients were enrolled; 38 patients had 60 mg MK-2206 QOD, whereas 33 received MK-2206 at 90, 135, 150, 200, 250, and 300 mg QW. The QW MK-2206 MTD was established at 200 mg following dose-limiting rash at 250 and 300 mg. QW dosing appeared to be similarly tolerated to QOD, with toxicities including rash, gastrointestinal symptoms, fatigue, and hyperglycemia. Significant AKT pathway blockade was observed with both continuous QOD and intermittent QW dosing of MK-2206 in serially obtained tumor and PRP specimens. The functional imaging studies demonstrated that complex multiparametric MRI protocols may be effectively implemented in a phase I trial.. Treatment with MK-2206 safely results in significant AKT pathway blockade in QOD and QW schedules. The intermittent dose of 200 mg QW is currently used in phase II MK-2206 monotherapy and combination studies (NCT00670488).

Topics: Adult; Aged; Antineoplastic Agents; Biomarkers; Diagnostic Imaging; Drug Administration Schedule; Drug Monitoring; Female; Heterocyclic Compounds, 3-Ring; Humans; Magnetic Resonance Imaging; Male; Maximum Tolerated Dose; Middle Aged; Neoplasm Staging; Neoplasms; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-akt; Treatment Outcome

Two strategies to interrogate the insulin growth factor 1 receptor (IGF-1R) pathway were investigated: vertical inhibition with dalotuzumab and MK-2206 or ridaforolimus to potentiate PI3K pathway targeting and horizontal cross-talk inhibition with dalotuzumab and MK-0752 to exert effects against cellular proliferation, angiogenesis, and stem cell propagation.. A phase I, multi-cohort dose escalation study was conducted in patients with advanced solid tumours. Patients received dalotuzumab (10 mg kg(-1)) and escalating doses of MK-2206 (90-200 mg) or escalating doses of dalotuzumab (7.5-10 mg kg(-1)) and MK-0752 (1800 mg) weekly. Upon maximum tolerated dose determination, patients with low-RAS signature, high-IGF1 expression ovarian cancer were randomised to dalotuzumab/MK-2206 versus dalotuzumab/ridaforolimus, whereas patients with high IGF1/low IGF2 expression colorectal cancer received dalotuzumab/MK-0752.. A total of 47 patients were enrolled: 29 in part A (18 in the dalotuzumab/MK-2206 arm and 11 in the dalotuzumab/MK-0752 arm) and 18 in part B (6 in each arm). Dose-limiting toxicities (DLTs) for dalotuzumab/MK-2206 included grade 4 neutropenia and grade 3 serum sickness-like reaction, maculopapular rash, and gastrointestinal inflammation. For dalotuzumab/MK-0752, DLTs included grade 3 dehydration, rash, and diarrhoea. Seven patients remained on study for >4 cycles.. Dalotuzumab/MK-2206 and dalotuzumab/MK-0752 combinations were tolerable. Further developments of prospectively validated predictive biomarkers to aid in patient selection for anti-IGF-1R therapies are needed.

Topics: Adult; Aged; Aged, 80 and over; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Antineoplastic Combined Chemotherapy Protocols; Benzene Derivatives; Biomarkers, Tumor; Clinical Trials, Phase II as Topic; Clinical Trials, Phase III as Topic; Cohort Studies; Female; Follow-Up Studies; Heterocyclic Compounds, 3-Ring; Humans; Male; Middle Aged; Neoplasm Staging; Neoplasms; Prognosis; Propionates; Proto-Oncogene Proteins c-akt; Randomized Controlled Trials as Topic; Receptor, IGF Type 1; Receptors, Notch; Sirolimus; Sulfones; Tissue Distribution; TOR Serine-Threonine Kinases

AKT signaling is frequently deregulated in human cancers. MK-2206 is a potent, oral allosteric inhibitor of all AKT isoforms with antitumor activity in preclinical models. A phase I study of MK-2206 was conducted to investigate its safety, maximum-tolerated dose (MTD), pharmacokinetics (PKs), pharmacodynamics (PDs), and preliminary antitumor efficacy.. Patients with advanced solid tumors received MK-2206 on alternate days. Paired tumor biopsies were mandated at the MTD for biomarker studies. PD studies incorporated tumor and hair follicle analyses, and putative predictive biomarker studies included tumor somatic mutation analyses and immunohistochemistry for phosphatase and tensin homolog (PTEN) loss.. Thirty-three patients received MK-2206 at 30, 60, 75, or 90 mg on alternate days. Dose-limiting toxicities included skin rash and stomatitis, establishing the MTD at 60 mg. Drug-related toxicities included skin rash (51.5%), nausea (36.4%), pruritus (24.2%), hyperglycemia (21.2%), and diarrhea (21.2%). PKs (area under the concentration-time curve from 0 to 48 hours and maximum measured plasma concentration) were dose proportional. Phosphorylated serine 473 AKT declined in all tumor biopsies assessed (P = .015), and phosphorylated threonine 246 proline-rich AKT substrate 40 was suppressed in hair follicles at 6 hours (P = .008), on days 7 (P = .028) and 15 (P = .025) with MK-2206; reversible hyperglycemia and increases in insulin c-peptide were also observed, confirming target modulation. A patient with pancreatic adenocarcinoma (PTEN loss; KRAS G12D mutation) treated at 60 mg on alternate days experienced a decrease of approximately 60% in cancer antigen 19-9 levels and 23% shrinkage in tumor measurements. Two patients with pancreatic neuroendocrine tumors had minor tumor responses.. MK-2206 was well tolerated, with evidence of AKT signaling blockade. Rational combination trials are ongoing to maximize clinical benefit with this therapeutic strategy.

Topics: Adult; Aged; Aged, 80 and over; Dose-Response Relationship, Drug; Female; Heterocyclic Compounds, 3-Ring; Humans; Male; Middle Aged; Neoplasms; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-akt

Topics: Animals; Antineoplastic Agents; Apoptosis; Cell Line, Tumor; Cell Proliferation; Ceramides; Drug Design; Drug Synergism; Female; G1 Phase Cell Cycle Checkpoints; Heterocyclic Compounds, 3-Ring; Humans; Mice, Inbred BALB C; Naphthalenes; Neoplasms; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-akt; Reactive Oxygen Species

As evidenced by the behavior of loss-of-function mutants of PTEN in the context of a gain-of-function mutation of AKT1, the PTEN-AKT1 signaling pathway plays a critical role in human cancers. In this study, we demonstrated that a deficiency in PTEN or activation of AKT1 potentiated the expression of platelet-derived growth factor receptor α (PDGFRα) based on studies on Pten-/- mouse embryonic fibroblasts, human cancer cell lines, the hepatic tissues of Pten conditional knockout mice, and human cancer tissues. Loss of PTEN enhanced PDGFRα expression via activation of the AKT1-CREB signaling cascade. CREB transactivated PDGFRα expression by direct binding of the promoter of the PDGFRα gene. Depletion of PDGFRα attenuated the tumorigenicity of Pten-null cells in nude mice. Moreover, the PI3K-AKT signaling pathway has been shown to positively correlate with PDGFRα expression in multiple cancers. Augmented PDGFRα was associated with poor survival of cancer patients. Lastly, combination treatment with the AKT inhibitor MK-2206 and the PDGFR inhibitor CP-673451 displayed synergistic anti-tumor effects. Therefore, activation of the AKT1-CREB-PDGFRα signaling pathway contributes to the tumor growth induced by PTEN deficiency and should be targeted for cancer treatment.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Benzimidazoles; Cell Line, Tumor; Cell Proliferation; Cyclic AMP Response Element-Binding Protein; Fibroblasts; Gene Expression Regulation, Neoplastic; HEK293 Cells; Heterocyclic Compounds, 3-Ring; Humans; Liver; Male; Mice, Inbred BALB C; Mice, Knockout; Mice, Nude; Neoplasms; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-akt; PTEN Phosphohydrolase; Quinolines; Receptor, Platelet-Derived Growth Factor alpha; Signal Transduction; Xenograft Model Antitumor Assays

Whilst effects of anti-cancer drugs have been thoroughly explored, little is known about the repercussion of drug cessation. However, this has important clinical relevance since several clinical protocols such as intermittent drug scheduling lead to frequent drug discontinuation. In this study, we have thus investigated the consequences of withdrawal of agents that target the PI3K/AKT/mTOR signaling pathway in cancer cells. We report that washout of kinase inhibitors of mTOR or PI3K inhibitors led to a rapid and sustainable overactivation of AKT. Consequently, proliferation of tumor cells was significantly higher following drug washout in cancer cells that were pre-treated with mTOR or PI3K inhibitors compared to untreated cells. This effect was prevented by the addition of an AKT inhibitor following drug washout. Rebound AKT overactivation induced by mTOR or PI3K inhibitors discontinuation was mediated by IGF-1R, as demonstrated by its prevention in the presence of an IGF-1R inhibitor and by increased IGF-1R phosphorylation in treated cells versus control cells. Taken together, our results show that discontinuation of PI3K or mTOR inhibitors results in AKT overactivation that promotes tumor growth. They further highlight the benefit of adding an AKT inhibitor following cessation of PI3K or mTOR inhibitors.

Topics: Antineoplastic Agents; Cell Line, Tumor; Cell Proliferation; Heterocyclic Compounds, 3-Ring; HT29 Cells; Humans; Neoplasms; Phosphoinositide-3 Kinase Inhibitors; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-akt; Receptor, IGF Type 1; TOR Serine-Threonine Kinases

Monocyte-derived dendritic cell (moDC)-based cancer therapies intended to elicit antitumor T-cell responses have limited efficacy in most clinical trials. However, potent and sustained antitumor activity in a limited number of patients highlights the therapeutic potential of moDCs.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Cancer Vaccines; Cell Communication; Chromones; Dendritic Cells; Heterocyclic Compounds, 3-Ring; Humans; Lymphocyte Activation; Male; Mice; Morpholines; Neoplasms; Protein Kinase Inhibitors; T-Lymphocyte Subsets

Balanced deoxyribonucleotides pools are essential for cell survival and genome stability. Ribonucleotide reductase is the rate-limiting enzyme for the production of deoxyribonucleotides. We report here that p53 suppresses ribonucleotide reductase subunit 1 (RRM1) and 2 (RRM2) via inhibiting mammalian target of rapamycin complex 1 (mTORC1). In vitro, cancer cell lines and mouse embryonic fibroblast cells were treated with different concentrations of pharmacological inhibitors for different times. In vivo, rhabdomyosarcoma Rh30 cell tumor-bearing mice were treated with rapamycin or AZD8055. Protein levels and phosphorylation status were assessed by immunoblotting and mRNA levels were determined by real time RT-PCR. Pharmacological inhibition of mTORC1 with rapamycin, mTOR kinase with AZD8055 or protein kinase B with MK2206 resulted in decrease of RRM1 and RRM2 in Rh30 cells both in vitro and in mouse tumor xenografts. Moreover, eukaryotic translational initiation factor 4E-binding proteins 1 and 2 double knockout mouse embryonic fibroblast cells demonstrated an elevation of RRM1 and RRM2. Furthermore, down-regulation of mTOR-protein kinase B signaling or cyclin dependent kinase 4 led to decrease of RRM1 and RRM2 mRNAs. In addition, TP53 mutant cancer cells had elevation of RRM1 and RRM2, which was reduced by rapamycin. Importantly, human double minute 2 inhibitor nutlin-3 decreased RRM1 and RRM2 in TP53 wild type rhabdomyosarcoma Rh18 but not in TP53 mutated Rh30 cells. Our data demonstrated that mTOR enhances the cap-dependent protein translation and gene transcription of RRM1 and RRM2. Our findings might provide an additional mechanism by which p53 maintains genome stability.

Topics: A549 Cells; Animals; Cell Line, Tumor; Cells, Cultured; Gene Expression Regulation, Neoplastic; Heterocyclic Compounds, 3-Ring; Humans; Mechanistic Target of Rapamycin Complex 1; Mice, Knockout; Mice, SCID; Morpholines; Mutation; Neoplasms; Ribonucleoside Diphosphate Reductase; RNA Interference; Sirolimus; Tumor Suppressor Protein p53; Tumor Suppressor Proteins; Xenograft Model Antitumor Assays

There is limited knowledge about the metabolic reprogramming induced by cancer therapies and how this contributes to therapeutic resistance. Here we show that although inhibition of PI3K-AKT-mTOR signaling markedly decreased glycolysis and restrained tumor growth, these signaling and metabolic restrictions triggered autophagy, which supplied the metabolites required for the maintenance of mitochondrial respiration and redox homeostasis. Specifically, we found that survival of cancer cells was critically dependent on phospholipase A2 (PLA2) to mobilize lysophospholipids and free fatty acids to sustain fatty acid oxidation and oxidative phosphorylation. Consistent with this, we observed significantly increased lipid droplets, with subsequent mobilization to mitochondria. These changes were abrogated in cells deficient for the essential autophagy gene

Topics: Animals; Antineoplastic Agents; Apoptosis; Autophagy; Benzamides; Cell Line, Tumor; Cell Respiration; Cell Survival; Heterocyclic Compounds, 3-Ring; Humans; Lipid Droplets; Mice; Mitochondria; Neoplasms; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Phospholipase A2 Inhibitors; Phospholipids; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-akt; Pyrimidines; Signal Transduction; Tumor Cells, Cultured

The effects of selective phosphoinositide 3-kinase (PI3K) and AKT inhibitors were compared in human tumor cell lines in which the pathway is dysregulated. Both caused inhibition of AKT, relief of feedback inhibition of receptor tyrosine kinases, and growth arrest. However, only the PI3K inhibitors caused rapid induction of cell death. In seeking a mechanism for this phenomenon, we found that PI3K inhibition, but not AKT inhibition, causes rapid inhibition of wild-type RAS and of RAF-MEK-ERK signaling. Inhibition of RAS-ERK signaling is transient, rebounding a few hours after drug addition, and is required for rapid induction of apoptosis. Combined MEK and AKT inhibition also promotes cell death, and in murine models of HER2(+) cancer, either pulsatile PI3K inhibition or combined MEK and AKT inhibition causes tumor regression. We conclude that PI3K is upstream of RAS and AKT and that pulsatile inhibition of both pathways is sufficient for effective antitumor activity.

Topics: Apoptosis; Cell Line, Tumor; Heterocyclic Compounds, 3-Ring; Humans; Lapatinib; MAP Kinase Signaling System; MCF-7 Cells; Neoplasms; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-akt; Pyrimidines; Quinazolines

MK-2206 is a small molecule allosteric inhibitor of Akt/PKB that is undergoing clinical trials for treatment of cancer.. MK-2206 was tested against the PPTP in vitro panel using a 96-hour exposure (1.0 nM-10 µM), and in vivo using thrice weekly dosing for a planned 4 weeks at its maximum tolerated dose (MTD) of 180 mg/kg.. In vitro, the median relative IC(50) value for MK-2206 was 2.2 µM. Four cell lines with IC(50) values < 200 nM included two ALL cell lines (COG-LL-317 and RS4;11), an AML cell line with an activating KIT mutation (Kasumi-1), and a Ewing sarcoma cell line (CHLA-10). In vivo, MK-2206 induced significant differences in EFS distribution compared to control in 12 of 29 (41%) of the evaluable solid tumor xenografts and in 2 of 8 (25%) of the evaluable ALL xenografts. Significant differences in EFS distribution were most frequently noted in the osteosarcoma panel (6 of 6). A single solid tumor xenograft (OS-31) had a greater than twofold increase in time to event compared to control animals, with all other solid tumor xenografts showing lesser degrees of tumor growth inhibition. Objective responses were not observed for either the solid tumor or ALL xenografts.. MK-2206 showed its most consistent activity in vitro against ALL cell lines and in vivo against osteosarcoma xenografts. However, no objective responses were observed in solid tumor or ALL xenografts. Further preclinical work evaluating MK-2206 in pediatric models in the combination therapy setting may contribute to its pediatric development.

Topics: Animals; Antineoplastic Agents; Cell Line, Tumor; Female; Heterocyclic Compounds, 3-Ring; Humans; Maximum Tolerated Dose; Mice; Neoplasms; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-akt; Xenograft Model Antitumor Assays

Human tumors often contain slowly proliferating cancer cells that resist treatment, but we do not know precisely how these cells arise. We show that rapidly proliferating cancer cells can divide asymmetrically to produce slowly proliferating "G0-like" progeny that are enriched following chemotherapy in breast cancer patients. Asymmetric cancer cell division results from asymmetric suppression of AKT/PKB kinase signaling in one daughter cell during telophase of mitosis. Moreover, inhibition of AKT signaling with small-molecule drugs can induce asymmetric cancer cell division and the production of slow proliferators. Cancer cells therefore appear to continuously flux between symmetric and asymmetric division depending on the precise state of their AKT signaling network. This model may have significant implications for understanding how tumors grow, evade treatment, and recur.

Topics: Blotting, Western; Breast Neoplasms; Cell Division; Cell Line, Tumor; Cell Survival; Dose-Response Relationship, Drug; Female; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; HCT116 Cells; Heterocyclic Compounds, 3-Ring; Humans; Luminescent Proteins; Microscopy, Confocal; Models, Biological; Molecular Structure; Neoplasms; Oligonucleotide Array Sequence Analysis; Proto-Oncogene Proteins c-akt; Reactive Oxygen Species; Resting Phase, Cell Cycle; Signal Transduction; Time Factors

Topics: Female; Heterocyclic Compounds, 3-Ring; Humans; Male; Neoplasms; Protein Kinase Inhibitors

Topics: Antineoplastic Agents; Aromatase Inhibitors; Benzimidazoles; Clinical Trials as Topic; Drug Synergism; Heterocyclic Compounds, 3-Ring; Humans; Neoplasms; Protein Kinase Inhibitors

The serine/threonine kinase Akt lies at a critical signaling node downstream of phosphatidylinositol-3-kinase and is important in promoting cell survival and inhibiting apoptosis. An Akt inhibitor may be particularly useful for cancers in which increased Akt signaling is associated with reduced sensitivity to cytotoxic agents or receptor tyrosine kinase inhibitors. We evaluated the effect of a novel allosteric Akt inhibitor, MK-2206, in combination with several anticancer agents. In vitro, MK-2206 synergistically inhibited cell proliferation of human cancer cell lines in combination with molecular targeted agents such as erlotinib (an epidermal growth factor receptor inhibitor) or lapatinib (a dual epidermal growth factor receptor/human epidermal growth factor receptor 2 inhibitor). Complementary inhibition of erlotinib-insensitive Akt phosphorylation by MK-2206 was one mechanism of synergism, and a synergistic effect was found even in erlotinib-insensitive cell lines. MK-2206 also showed synergistic responses in combination with cytotoxic agents such as topoisomerase inhibitors (doxorubicin, camptothecin), antimetabolites (gemcitabine, 5-fluorouracil), anti-microtubule agents (docetaxel), and DNA cross-linkers (carboplatin) in lung NCI-H460 or ovarian A2780 tumor cells. The synergy with docetaxel depended on the treatment sequence; a schedule of MK-2206 dosed before docetaxel was not effective. MK-2206 suppressed the Akt phosphorylation that is induced by carboplatin and gemcitabine. In vivo, MK-2206 in combination with these agents exerted significantly more potent tumor inhibitory activities than each agent in the monotherapy setting. These findings suggest that Akt inhibition may augment the efficacy of existing cancer therapeutics; thus, MK-2206 is a promising agent to treat cancer patients who receive these cytotoxic and/or molecular targeted agents.

Topics: Allosteric Regulation; Animals; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Blotting, Western; Camptothecin; Carboplatin; Carcinoma, Non-Small-Cell Lung; Caspases; Cell Line, Tumor; Cell Proliferation; Drug Synergism; Enzyme Activation; ErbB Receptors; Erlotinib Hydrochloride; Heterocyclic Compounds, 3-Ring; Humans; Lapatinib; Lung Neoplasms; Mice; Molecular Structure; Neoplasms; Proto-Oncogene Proteins c-akt; Quinazolines; Xenograft Model Antitumor Assays