MicroRNA-139 suppressed tumor cell proliferation, migration and invasion by directly targeting HDGF in epithelial ovarian cancer

The current study investigated the expression and functional roles of microRNA-139 (miR-139) on human epithelial ovarian cancer (EOC). Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was performed to measure miR-139 expression in EOC tissues and cell lines. The effects of miR-139 on EOC cell proliferation, migration and invasion were assessed using MTT, cell migration and invasion assays, respectively. Subsequently, the molecular mechanism underlying the tumor suppressive roles of miR-139 on EOC was determined by bioinformatics analysis, RT-qPCR, western blotting and the luciferase reporter assay. According to the results, it was identified that miR-139 was significantly downregulated in EOC tissues and cell lines. In addition, restoration of miR-139 suppressed tumor cell proliferation, migration and invasion in EOC. Furthermore, hepatoma-derived growth factor (HDGF) was identified as a target of miR-139 in EOC. Upregulation of HDGF could rescue the inhibitory effects exerted by miR-139 overexpression on EOC cell proliferation, migration and invasion. Collectively, the results indicated that miR-139 was downregulated in EOC, and acted as a tumor suppressor by directly targeting HDGF. To the best of our knowledge, this was the first study to identify that miR-139 contributes to the growth and metastasis of EOC.