Abstract: MicroRNAs, a group of posttranscriptional regulators of numerous genes, are active participators during the development and progression of ovarian cancer (OC). This study confirmed for the first time that miR-216a was gradually increased in normal, benign, borderline, and OC tissues and that its expression was significantly upregulated in all OC cell lines. Analysis of its clinical association demonstrated that elevated expression of miR-216a was associated with lymph node metastasis and advanced FIGO stage and was correlated with the poor survival of OC patients. Functional experiments showed that miR-216a overexpression potentiated the migration and invasion of CAOV3 cells while miR-216a inhibition reduced the migration and invasion of SKOV-3 cells. Both gain and lose of function assay showed that miR-216a promoted epithelial–mesenchymal transition (EMT) of OC cells. Mechanistically, phosphatase and tensin homolog (PTEN) was confirmed as a direct downstream target of miR-216a in OC cells. Alerting miR-216a expression in OC cells modulated the activity of PTEN/AKT pathway in OC cells. Furthermore, this study confirmed that miR-216a exerted its promoting effects on the metastatic behaviors and EMT of OC cells by inhibiting PTEN/AKT pathway. Taken together, this study demonstrates that miR-216a exerts a promoting role in the metastasis of OC and can serve as a promising biomarker and an attractive therapeutic target of OC.
Keywords: miR-216a, ovarian cancer, PTEN, epithelial-mesenchymal transition, metastasis, biomarker