Clinical significance of microRNA-125b and its contribution to ovarian carcinogenesis

The underlying mechanisms of recurrence and metastasis of epithelial ovarian cancer (EOC) are largely unknown. In the present study, we investigated the clinical significance of microRNA-125b (miR-125b) and its role in ovarian tumorigenesis and progression. Seventy patients of EOC and paired tissues were enrolled from 2015 to 2017. qRT-PCR was used to evaluate miR-125b expression in tumor tissues and EOC cell line. Gain-and-loss function of miR-125b was achieved to explore the changes in cell biological function. We found that miR-125b expression in EOC tissues, especially in the high-grade tissues (P < 0.001), was significantly lower compared to the matched adjacent noncancerous tissues and associated with pathological type, stage, and overall survival (P < 0.05). Upregulation of miR-125b promoted apoptosis and decreased cell survival rate and migration, and vice versa in vitro. Mechanistically, miR-125b negatively regulated S100A4, a metastasis-associated protein. MiR-125b overexpression significantly decreased tumor growth and inhibited lung metastasis in vivo. Our results supported that miR-125b contributes to the progression of EOC by targeting S100A4. It potentially acts as a potential biomarker and therapeutic target of EOC.