Abstract: Objective To investigate the expression of nuclear receptor coactivator 7 (NCOA7) in oral submucous fibrosis (OSF) and explore its effect on epithelial to mesenchymal transformation (EMT). Methods 30 cases of OSF tissues, and 15 cases of normal tissues were collected. The protein expression level of NCOA7 and Vimentin in OSF tissues was determined by immunohistochemical (IHC) method. NCOA7 protein and epithelial-mesenchymal transformation related proteins (E-cadherin, Vimentin) in arecoline-treated HOKs were detected by western blot. Results NCOA7 was highly expressed (P<0.05) in OSF tissues at protein level compared to normal oral mucosa. Epithelial basal cells showed a higher vimentin expression in OSF tissues. After 24 hours of treatment with different arecoline concentration, aberrant expression of NCOA7, E-cadherin, vimentin and α-SMA were found in a dose-depended manner. Conclusion Overexpression of NCOA7 was found in OSF tissues and arecoline stimulated epithelial cells and EMT process was found play a role in the pathogenesis of OSF. NCOA7 might be a new therapeutic target for OSF.

Key words: Oral submucous fibrosis, Nuclear receptor coactivator 7 (NCOA7), Epithelial to mesenchymal transformation (EMT), Arecoline, Human oral keratinocytes (HOKs)