akt-i-1-2-compound and Ovarian-Neoplasms

Recent genomics analysis of the high-grade serous subtype of epithelial ovarian cancer (EOC) show aberrations in the phosphatidylinositol 3-kinase (PI3K)/AKT pathway that result in upregulated signaling activity. Thus, the PI3K/AKT pathway represents a potential therapeutic target for aggressive high-grade EOC. We previously demonstrated that treatment of malignant ascites-derived primary human EOC cells and ovarian cancer cell lines with the allosteric AKT inhibitor Akti-1/2 induces a dormancy-like cytostatic response but does not reduce cell viability. In this report, we show that allosteric AKT inhibition in these cells induces cytoprotective autophagy. Inhibition of autophagy using chloroquine (CQ) alone or in combination with Akti-1/2 leads to a significant decrease in viable cell number. In fact, Akti-1/2 sensitizes EOC cells to CQ-induced cell death by exhibiting markedly reduced EC50 values in combination-treated cells compared with CQ alone. In addition, we evaluated the effects of the novel specific and potent autophagy inhibitor-1 (Spautin-1) and demonstrate that Spautin-1 inhibits autophagy in a Beclin-1-independent manner in primary EOC cells and cell lines. Multicellular EOC spheroids are highly sensitive to Akti-1/2 and CQ/Spautin-1 cotreatments, but resistant to each agent alone. Indeed, combination index analysis revealed strong synergy between Akti-1/2 and Spautin-1 when both agents were used to affect cell viability; Akti-1/2 and CQ cotreatment also displayed synergy in most samples. Taken together, we propose that combination AKT inhibition and autophagy blockade would prove efficacious to reduce residual EOC cells for supplying ovarian cancer recurrence.

Topics: Allosteric Regulation; Antineoplastic Agents; Ascites; Autophagy; Benzylamines; Cell Line, Tumor; Cell Survival; Chloroquine; Drug Resistance, Neoplasm; Drug Screening Assays, Antitumor; Drug Synergism; Female; Humans; Inhibitory Concentration 50; Ovarian Neoplasms; Proto-Oncogene Proteins c-akt; Quinazolines; Quinoxalines; Spheroids, Cellular

Pharmacological inhibition of the phosphoinositide 3-kinase (PI3K)/Akt pathway prevents G(1) cell cycle progression into S, resulting in G(1) accumulation. The hypothesis that this arrest might negatively impact on chemotherapeutic agents primarily effective in S, G(2) or M-phase was investigated.. Inhibition of PI3K/Akt pathway signaling via LY294002 and Akti-1/2 was demonstrated by immunoblotting. Cell cycle progression was determined by flow cytometric analysis. Cell proliferation was assayed using the XTT cell viability assay. The Chou and Talalay median effect principal was used to evaluate drug interaction.. In SKOV3 and IGROV1 human ovarian cancer cells, LY294002 and Akti-1/2 increased the percentage of cells in G(1) and reversed the cell cycle effects of cisplatin, paclitaxel, gemcitabine and topotecan. Pathway blockade synergistically enhanced the cytotoxicity of cisplatin and paclitaxel, but antagonized gemcitabine and topotecan effects.. Pharmacological PI3K/Akt inhibition antagonizes the efficacy of chemotherapeutic agents primarily effective in the S or G(2)-phase of the cell cycle.

Topics: Antineoplastic Combined Chemotherapy Protocols; Benzylamines; Cell Line, Tumor; Chromones; Cisplatin; Deoxycytidine; Dose-Response Relationship, Drug; Drug Synergism; Female; G1 Phase Cell Cycle Checkpoints; Gemcitabine; Humans; Morpholines; Ovarian Neoplasms; Paclitaxel; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Phosphorylation; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-akt; Quinoxalines; Signal Transduction; Topotecan

This paper describes the rapid assembly of four different classes of potent Akt inhibitors from a common intermediate. Among them, a pyridopyrimidine series displayed the best intrinsic and cell potency against Akt1 and Akt2. This series also showed a promising pharmacokinetic profile and excellent selectivity over other closely related kinases.

Topics: Allosteric Site; Animals; Apoptosis; Caspases; Dogs; Female; Humans; Male; Metabolic Clearance Rate; Molecular Structure; Ovarian Neoplasms; Phosphorylation; Prostatic Neoplasms; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-akt; Pyridines; Pyrimidines; Structure-Activity Relationship; TNF-Related Apoptosis-Inducing Ligand; Tumor Cells, Cultured