miR-200c inhibits the arecoline-associated myofibroblastic transdifferentiation in buccal mucosal fibroblasts

Background/purpose: MicroRNA-200c (miR-200c) recently emerged as an important regulator of tumorigenesis and cancer metastasis, however, its role in regulating oral submucous fibrosis (OSF) remains unknown. In this study, we investigated the functional role of miR-200c in myofibroblastic differentiation activity and identified its potential target.

Methods: qRT-PCR was applied to assess the expression of miR-200c in OSF tissues and fibrotic buccal mucosal fibroblasts (fBMFs). Arecoline, a major areca nut alkaloid, was utilized to explore whether the expression of miR-200c would alter following stimulation. Collagen gel contraction, migration and invasion capabilities were examined in arecoline-stimulated BMFs as wells as in fBMFs. Luciferase reporter assay was conducted to show the relationship between miR-200c and ZEB1.

Results: Our results showed that the expression of miR-200c was downregulated in OSF specimen and fBMFs. Arecoline treatment dose-dependently reduced the relative expression of miR-200c in normal BMFs. Overexpression of miR-200c impeded the arecoline-induced collagen gel contraction, migration, invasion and wound healing capacities. Moreover, ectopic expression of miR-200c in fBMFs successfully reduced the increased collagen gel contractility and invasion abilities. Our results demonstrated that ZEB1 was a direct target of miR-200c, and overexpression of miR-200c inhibited the expression of ZEB1 and α-SMA.

Conclusion: These findings suggest that downregulation of miR-200c in OSF may be involved in the pathogenesis of areca nut-associated OSF through regulation of ZEB1.