Dual effects of metformin and resveratrol on compromising viability of endometrial cancer cells

Raising of mitogenic and anti-apoptotic agents - such as insulin, insulin-like growth factor type 1, and estrogen - during obesity and diabetes mellitus (types 1 and 2) favors the endometrial cancer (EC) development. Metformin, commonly used for treating type 2 diabetes, and resveratrol, a natural polyphenol, can both decrease cancer cell proliferation by modulating the PI3K/Akt/mTOR pathway. We evaluate the effects of metformin and/or resveratrol in an in vitro model of human type 1 endometrioid EC. Ishikawa cells were treated with 0.1 to 50 mM of metformin and/or 0.1 to 75 μM of resveratrol from 24 h to 72 h. Analyses assessed cell viability, cytotoxicity, caspases activation, mitochondrial function, cellular death, cell cycle, and the PI3K/Akt/mTOR pathway gene expression. In-silico analysis was conducted using Cytoscape. Metformin induced mitochondrial swelling, caspase-mediated apoptosis, and cell cycle arrest. Resveratrol decreased mitochondrial mass, cytotoxicity, and induced cell cycle arrest. Combined treatment with the highest concentrations reduced mitochondrial activity, cytotoxicity, and caspase activation while maintaining apoptotic features and cell cycle arrest. Resveratrol attenuated the toxic effects of metformin but it could be inducing a caspase-independent cell death in co-treated cells. Although in-silico analysis suggested potential molecular targets and interconnected mechanisms, lower concentrations did not alter PI3K/Akt/mTOR gene expression.