miR-93-5p targets Smad7 to regulate the transforming growth factor-β1/Smad3 pathway and mediate fibrosis in drug-resistant prolactinoma.

•We evaluated the mechanisms of fibrosis in prolactinoma.•miR-93-5p was significantly upregulated in highly fibrotic prolactinoma samples.•miR-93-5p was negatively correlated with Smad7 and positively correlated with TGF-β1.•miR-93-5p downregulated Smad7 and activate TGF-β1/Smad3 signaling-mediated fibrosis.•Targetting miR-93-5p may inhibit fibrosis and reduce drug resistance in prolactinoma.