MiR-378a-3p sensitizes ovarian cancer cells to cisplatin through targeting MAPK1/GRB2

Abstract

Ovarian cancer has gradually become one of the commonest gynecological tumor in the world. Although various therapies have been developed by researchers, the chemoresistance of ovarian cancer is still a huge challenge. MircroRNAs (miRNAs) have been widely studied due to their anti-oncogenic functions. MiR-378a-3p has been reported to sensitize breast cancer cells to chemotherapy. Here, we hypothesized that miR-378a-3p is a potential chemosensitizer in ovarian cancer. Firstly, miR-378a-3p was uncovered to down-regulated in ovarian cancer tissues and cell lines through using qRT-PCR analysis and northern blot analysis. According to the result of Kaplan Meier analysis, low expression of miR-378a-3p is closely associated with unfavorable prognosis of ovarian cancer patients. Subsequently, gain-of function assays indicated that miR-378a-3p suppressed cell proliferation and promoted cell apoptosis. Moreover, miR-378a-3p was found to enhance cisplatin sensitivity of ovarian cancer cells. Mechanism investigations suggested that MAPK1 and GRB2 are two targets of miR-378a-3p. Finally, rescue assays revealed that MAPK1 and GRB2 can reverse the effects of miR-378a-3p on chemosensitivity of ovarian cancer cells. In conclusion, miR-378a-3p enhanced the sensitivity of ovarian cancer cells to cisplatin through targeting MAPK1 and GRB2.