The Down Regulation of microRNA-200b Expression in Oral Submucous Fibrosis

Objectives: Oral submucous fibrosis (OSF) is considered as pre-cancerous condition which is highly associated with areca quid chewing. The pathologic mechanism of OSF still needs to be further clarified. Analysis of microRNAs (miRNAs) may be crucial to better understanding fibotic disease and with an aim to eventually identify novel therapeutic targets. The purpose of this study is to investigate the roles of miR-200b in the pathogenesis of OSF
Methods: We compared the expression of miR-200b between normal buccal mucosa and areca quid chewing-associated OSF specimens by using quantitative real-time reverse transcription-polymerase chain reaction. Furthermore, arecoline, a major areca nut alkaloid, was challenged to normal buccal mucosa fibroblasts (BMFs) to elucidate whether miR-200b expression could affect by arecoline evaluated by collagen gel contraction and cell migration assays.
Results: miR-200b was found to significantly down-regulated in areca quid chewing-associated OSF specimens (p<0.05). In addition, the treatment of arecoline dose-dependently decreased miR-200b expression in BMFs (p<0.05). The myofibroblast activity including collagen gel contraction and migration capability was also induced by arecoline (p<0.05), while the overexpression miR-200b could reverse these phenomena.
Conclusions: Taken together, these results suggest that miR-200b expression is significantly down regulated in OSF tissues from areca quid chewers and arecoline may among other constituents be responsible for the decreased miR-200b expression in vivo. miR-200b may serve as a new therapeutic target for the treatment of OSF in the future.