MiR-663a Inhibits Radiation-Induced Epithelium-to-Mesenchymal Transition by Targeting TGF-β1.

miR-663a has been reported to be downregulated by X-ray irradiation and participates in radiation-induced bystander effect via TGF-β1. The goal of this study was to explore the role of miR-663a during radiation-induced Epithelium-to-mesenchymal transition (EMT).TGF-β1 or IR was used to induce EMT. After miR-663a transfection, cell migration and cell morphological changes were detected and the expression levels of miR-663a, TGF-β1, and EMT-related factors were quantified.Enhancement of cell migration and promotion of mesenchymal changes induced by either TGF-β1 or radiation were suppressed by miR-663a. Furthermore, both X-ray and carbon ion irradiation resulted in the upregulation of TGF-β1 and downregulation of miR-663a, while the silencing of TGF-β1 by miR-663a reversed the EMT process after radiation.Our findings demonstrate an EMT-suppressing effect by miR-663a via TGF-β1 in radiation-induced EMT.