Hypoxia induces autophagy in PA-1 ovarian teratoma cells and resistance to growth inhibition and apoptosis by chemotherapeutic agent cis-diamminedichloroplatinum

Pathological hypoxia exists in solid tumors and it creates a microenvironment for tumor cells which has a critical and complicated implication for cancer. Hypoxia can also activate autophagy which plays a dual role in cancer. In this study the authors analyzed the effect of hypoxia, the autophagy inhibitor 3-methyladenine (3-MA), cis-diamminedichloroplatinum (CDDP, cisplatin), and any combination of them on PA-1 cells (a human ovarian cancer cell line) with a series of assays, focusing on autophagy induction, cell growth inhibition, and cell death by CDDP. CDDP caused apoptosis in nonnoxic PA-1 cells and autophagy upon hypoxia treatment decreased apoptosis induction in hypoxic cells by CDDP, which has implications in cancer chemotherapy resistance.