mk-2206 and temsirolimus

The mammalian target of rapamycin (mTOR) is a serine/threonine kinase that integrates nutrients to execute cell growth. We hypothesized that mTOR is influential in the intervertebral disc-largest avascular, low-nutrient organ. Our objective was to identify the optimal mTOR inhibitor for treating human degenerative disc disease.. mTOR complex 1 (mTORC1) regulates p70/ribosomal S6 kinase (p70/S6K), negatively regulates autophagy, and is controlled by Akt. Akt is controlled by phosphatidylinositol 3-kinase (PI3K) and mTOR complex 2 (mTORC2). mTORC1 inhibitors-rapamycin, temsirolimus, everolimus, and curcumin, mTORC1&mTORC2 inhibitor-INK-128, PI3K&mTOR inhibitor-NVP-BEZ235, and Akt inhibitor-MK-2206-were applied to human disc nucleus pulposus (NP) cells. mTOR signaling, autophagy, apoptosis, senescence, and matrix metabolism were evaluated.. mTORC1 inhibitors decreased p70/S6K but increased Akt phosphorylation, promoted autophagy with light chain 3 (LC3)-II increases and p62/sequestosome 1 (p62/SQSTM1) decreases, and suppressed pro-inflammatory interleukin-1 beta (IL-1β)-induced apoptotic terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) positivity (versus rapamycin, 95% confidence interval (CI) -0.431 to -0.194; temsirolimus, 95% CI -0.529 to -0.292; everolimus, 95% CI -0.477 to -0.241; curcumin, 95% CI -0.248 to -0.011) and poly (ADP-ribose) polymerase (PARP) and caspase-9 cleavage, senescent senescence-associated beta-galactosidase (SA-β-gal) positivity (versus rapamycin, 95% CI -0.437 to -0.230; temsirolimus, 95% CI -0.534 to -0.327; everolimus, 95% CI -0.485 to -0.278; curcumin, 95% CI -0.210 to -0.003) and p16/INK4A expression, and catabolic matrix metalloproteinase (MMP) release and activation. Meanwhile, dual mTOR inhibitors decreased p70/S6K and Akt phosphorylation without enhanced autophagy and suppressed apoptosis, senescence, and matrix catabolism. MK-2206 counteracted protective effects of temsirolimus. Additional disc-tissue analysis found relevance of mTOR signaling to degeneration grades.. mTORC1 inhibitors-notably temsirolimus with an improved water solubility-but not dual mTOR inhibitors protect against inflammation-induced apoptosis, senescence, and matrix catabolism in human disc cells, which depends on Akt and autophagy induction.

Topics: Adult; Aged; Aged, 80 and over; Apoptosis; Autophagy; Benzoxazoles; beta-Galactosidase; Cellular Senescence; Curcumin; Everolimus; Extracellular Matrix; Female; Heterocyclic Compounds, 3-Ring; Humans; Imidazoles; Inflammation; Male; Matrix Metalloproteinases; Mechanistic Target of Rapamycin Complex 1; Mechanistic Target of Rapamycin Complex 2; Microtubule-Associated Proteins; Middle Aged; Nucleus Pulposus; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-akt; Pyrimidines; Quinolines; Ribosomal Protein S6 Kinases, 70-kDa; Sequestosome-1 Protein; Sirolimus

B-precursor acute lymphoblastic leukemia (B-pre ALL) is a malignant disorder characterized by the abnormal proliferation of B-cell progenitors. The prognosis of B-pre ALL has improved in pediatric patients, but the outcome is much less successful in adults. Constitutive activation of the phosphatidylinositol 3-kinase (PI3K), Akt and the mammalian target of rapamycin (mTOR) (PI3K/Akt/mTOR) network is a feature of B-pre ALL, where it strongly influences cell growth and survival. RAD001, a selective mTORC1 inhibitor, has been shown to be cytotoxic against many types of cancer including hematological malignancies. To investigate whether mTORC1 could represent a target in the therapy of B-pre ALL, we treated cell lines and adult patient primary cells with RAD001. We documented that RAD001 decreased cell viability, induced cell cycle arrest in G0/G1 phase and caused apoptosis in B-pre ALL cell lines. Autophagy was also induced, which was important for the RAD001 cytotoxic effect, as downregulation of Beclin-1 reduced drug cytotoxicity. RAD001 strongly synergized with the novel allosteric Akt inhibitor MK-2206 in both cell lines and patient samples. Similar results were obtained with the combination CCI-779 plus GSK 690693. These findings point out that mTORC1 inhibitors, either as a single agent or in combination with Akt inhibitors, could represent a potential therapeutic innovative strategy in B-pre ALL.

Topics: Apoptosis; Autophagy; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Proliferation; Everolimus; Heterocyclic Compounds, 3-Ring; Humans; Mechanistic Target of Rapamycin Complex 1; Multiprotein Complexes; Oxadiazoles; Phosphoinositide-3 Kinase Inhibitors; Precursor B-Cell Lymphoblastic Leukemia-Lymphoma; Proto-Oncogene Proteins c-akt; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases

Neuroendocrine tumors of the pancreas (pNETs) are classified on the basis of their differentiation as well as the functional status. Current treatment options for non resectable disease include everolimus, sunitinib, somatostatin analogs and chemotherapy. A number of trials with novel compounds and drug combinations were reported at the recent ASCO Annual Meeting. Pasireotide is a novel somatostatin analog with broader affinity for the somatostatin receptors compared to the traditional octreotide and lantreotide and it appears to be safe in patients with pNETs according to a phase I study (Abstract #e15126). The combination of octreotide with everolimus showed promising response rate and progression free survival in a phase II study (Abstract #4136). In another phase II study, the AKT inhibitor MK-2206 was well tolerated with moderate efficacy (Abstract #e15133). Last but not least, we discuss the updated data from a phase II study that used the combination of temsirolimus with bevacizumab in patients with advanced pNETs (Abstract #4032).

Topics: Antibodies, Monoclonal, Humanized; Antineoplastic Combined Chemotherapy Protocols; Bevacizumab; Clinical Trials, Phase I as Topic; Clinical Trials, Phase II as Topic; Everolimus; Heterocyclic Compounds, 3-Ring; Humans; Neuroendocrine Tumors; Octreotide; Pancreatic Neoplasms; Protein Kinase Inhibitors; Sirolimus; Treatment Outcome

The phosphoinositide 3-kinase (PI3K)/Akt pathway is widely postulated to be an effective therapeutic target in thyroid cancer.. The aim of the study was to test the therapeutic potential of the novel Akt inhibitor MK2206 for thyroid cancer.. We examined the effects of MK2206 on thyroid cancer cells with respect to the genotypes of the PI3K/Akt pathway.. Proliferation of thyroid cancer cells OCUT1, K1, FTC133, C643, Hth7, and TPC1, which harbored PIK3CA, PTEN, Ras, or RET/PTC mutations that could activate the PI3K/Akt pathway, was potently inhibited by MK2206 with IC(50) values mostly below or around 0.5 μm. In contrast, no potent inhibition by MK2206 was seen in most of the Hth74, KAT18, SW1736, WRO, and TAD2 cells that did not harbor mutations in the PI3K/Akt pathway. The inhibition efficacy was also genetic-selective. Specifically, the average inhibition efficacies were 59.2 ± 11.3 vs. 36.4 ± 8.8% (P = 0.005) at 1 μm MK2206 and 64.4 ± 11.5 vs. 38.5 ± 18.9% (P = 0.02) at 3 μm MK2206 for cells with mutations vs. cells without. The SW1736 cell, lacking mutations in the PI3K/Akt pathway, had minimal response to MK2206, but transfection with exogenous PIK3CA mutants, PIK3CA H1047R and E545K, significantly increased its sensitivity to MK2206. MK2206 also completely overcame the feedback activation of Akt from temsirolimus-induced mammalian target of rapamycin suppression, and the two inhibitors synergistically inhibited thyroid cancer cell growth.. Our study demonstrates a genetic selectivity of MK2206 in inhibiting thyroid cancer cells by targeting the PI3K/Akt pathway, supporting a clinical trial in thyroid cancer.

Topics: Adenocarcinoma, Follicular; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Cell Line, Tumor; Cell Proliferation; Down-Regulation; Drug Evaluation, Preclinical; Drug Synergism; Heterocyclic Compounds, 3-Ring; Humans; Phosphatidylinositol 3-Kinases; Phosphorylation; Point Mutation; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-akt; Signal Transduction; Sirolimus; Substrate Specificity; Thyroid Carcinoma, Anaplastic; Thyroid Neoplasms