miR-96-5p regulated TGF-β/SMAD signaling pathway and suppressed endometrial cell viability and migration via targeting TGFBR1.

We previously performed high throughput RNA-seq in paired eutopic and ectopic endometrial specimen of endometriosis patients, and validated the results by qRT-PCR in endometriosis endometrial tissues. MiR-96-5p was significantly downregulated in ectopic endometrial tissues compared to eutopic tissues. In order to identify the role of miR-96-5p in endometriosis and endometrial cells, and investigate the underlying mechanisms, the Ishikawa and End1/E6E7 cell lines were transfected with miR-96-5p mimics, miR-96-5p inhibitors or TGFBR1 siRNA. The expression of TGF-β/SMAD signaling pathway components and epithelial-mesenchymal transition (EMT) markers were examined by qRT-PCR and western blot, and cell viability and migration were determined by CCK-8, transwell and wound healing assays, respectively. We discovered miR-96-5p to be significantly downregulated while TGFBR1 was distinctly up-regulated in endometriosis. Overexpression of miR-96-5p inhibited endometrial cells viability and migration, while inhibition of miR-96-5p had opposite effect. Furthermore, we confirmed TGFBR1 was a direct target of miR-96-5p. Overexpression of miR-96-5p could block the TGF-β/SMAD signaling pathway via targeting TGFBR1 and reverse the TGF-β1 induced EMT in endometrial cell lines. In conclusion, we demonstrated that miR-96-5p interacted with TGF-β/SMAD signaling pathway and blocked the TGF-β1 induced EMT in endometrial cells via directly targeting TGFBR1.