Anticancer effect of 7-hydroxycoumarin in cisplatin-resistant ovarian cancer cell is mediated via apoptosis induction, caspase activation and cell cycle arrest at G2M phase

Purpose: To investigate the anticancer effects of 7-hydroxycoumarin against cisplatin-resistant ovarian cancer cell line, and the underlying mechanism(s). Methods: Cell proliferation was determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. The 4',6-diamidino-2-phenylindole (DAPI) and acridine orange/ethidium bromide (AO/EB) dual staining methods were used for measuring cell apoptosis in terms of DNA damage. Flow cytometry was used for analysis of mitosis of cancer cells, while protein expression levels were assayed with western blotting. Results: The 7-hydroxycoumarin preferentially inhibited the proliferation of the ovarian cancer cells, but had significantly less prominent effects on normal cells (p < 0.05). The decrease in cell proliferation was due to induction of cell apoptosis via caspase-linked apoptotic pathway. Treatment with 7-hdoxycoumarin further led to the arrest of cancer cell cycle at G2/M stage (p < 0.05) via down-regulation of the expressions of regulatory proteins that promote mitotic entry. Conclusion: 7-Hydroxycoumarin exerts significant anticancer effect against cisplatin-resistant ovarian cancer cells via decrease in cell proliferation, induction of apoptosis and mitotic cell cycle arrest. Thus, the compound could emerge as a vital lead molecule in the treatment of cisplatin-resistant type of human ovarian cancer.