MicroRNA-331-3p inhibits proliferation and metastasis of ovarian cancer by targeting RCC2

INTRODUCTION: Epithelial ovarian carcinoma (EOC) is one of the most lethal gynecologic malignancies, with a poor 5-year survival rate. Numerous studies have shown that microRNAs participate in the malignant behavior of ovarian cancer cells by directly targeting multiple oncogenes or tumor suppressor genes. MATERIAL AND METHODS: Reverse transcription-PCR was used to determine the level of miR-331-3p in EOC. Cells proliferation was measured with the Cell Counting Kit-8. Cell mobility were measured by wound-healing assay. Cell migration and invasion were measured by transwell assay. Luciferase assays were used to demonstrate that RCC2 was a directed target of miR-331-3p in EOC. Western blots were used to measure the protein expression. RESULTS: We found that the expression of microRNA-331-3p (miR-331-3p) in ovarian cancer cell lines is reduced (p < 0.01), and an increase of expression of miR-331-3p in ovarian cancer cells significantly inhibits cell proliferation (p < 0.001). Transwell and wound-healing assays showed that miR-331-3p inhibits the cell motility of ovarian cancer cells (p < 0.001). Regulator of chromosome condensation 2 (RCC2) was predicted to be a novel target for miR-331-3p. Our luciferase activity assay confirmed that RCC2 is directly targeted by miR-331-3p. RCC2 was negatively regulated by miR-331-3p (p < 0.001), and overexpression of RCC2 could restore the malignant behaviors of ovarian cancer cells, which was suppressed by miR-331-3p. CONCLUSIONS: These data indicate that miR-331-3p can inhibit proliferation, migration, and invasion of ovarian cancer cells via directly targeting RCC2. Our study provides potential therapeutic targets for the treatment of ovarian cancer.