MicroRNA-509-3p increases the sensitivity of epithelial ovarian cancer cells to cisplatin-induced apoptosis

Aims: XIAP is upregulated in chemoresistant epithelial ovarian cancer (EOC). However, the molecular mechanism of this dysregulation remains unclear. Materials & methods: The regulation of XIAP by miR-509-3p was investigated by luciferase reporter assay, real-time PCR and immunobloting, and the roles of miR-509-3p in cellular proliferation and apoptosis were accessed through MTT and DAPI assays. Results: miR-509-3p, a downregulated miRNA in chemoresistant EOC, can directly target the XIAP via its 3'UTR. Overexpression of miR-509-3p can not only downregulate the expression of XIAP in ovarian cancer cells but also inhibit the proliferation of EOC cells and increase their sensitivity to cisplatin-induced apoptosis. Conclusions: Our data suggest that restoring certain dysregulated miRNAs to their normal levels could increase the therapeutic effects of anticancer drugs.