MiR-520a-3p inhibits malignant progression of epithelial ovarian cancer by targeting SUV39H1 expression

Downregulation of microRNA-520a-3p (miR-520a-3p) has been demonstrated in several cancers, and miR-520a-3p has been shown to inhibit tumor progression, indicating its potential role as a tumor suppressor. In this study, we found that miR-520a-3p was also downregulated in epithelial ovarian cancer (EOC) tissues and cell lines. Functional assays showed that ectopic expression of miR-520a-3p suppressed EOC cell proliferation, invasion, and epithelial-mesenchymal transition (EMT) and induced cell cycle arrest in vitro. Similarly, overexpression of miR-520a-3p inhibited tumor growth and metastasis in vivo. Mechanistically, suppressor of variegation 39H1 (SUV39H1) was identified as a novel target of miR-520a-3p through biomedical databases and dual-luciferase reporter assay. Subsequently, SUV39H1 was observed to be negatively regulated by miR-520a-3p at the mRNA and protein levels, and inversely correlated with miR-520a-3p expression in EOC tissues. Furthermore, overexpression of SUV39H1 reversed the suppressive effects of miR-520a-3p in EOC cells. Collectively, these results suggest that the miR-520a-3p/SUV39H1 axis may contribute to EOC cell proliferation and metastasis, revealing miR-520a-3p as a potential therapeutic target for the treatment of EOC.