HMGB1 promotes the proliferation and invasion of oral squamous cell carcinoma via activating epithelial-mesenchymal transformation

This study aimed to investigate the role of high mobility group box-1 (HMGB1) expression in oral squamouscell carcinoma; HMGB1 promoted the proliferation and invasion of oral squamous cell carcinoma via activatingepithelial-mesenchymal transformation (EMT). In this study, RNA transfection was used to silence the expression ofHMGB1 in oral squamous cell carcinoma cells. CCK-8, cell clone formation and trans-well assays were used to detectthe proliferation and invasion of cells before and after HMGB1 silencing. qRT-PCR and Western blot were used todetect changes in EMT marker protein expression before and after transfection. HMGB1 was significantly higher inOSCC tissues than in adjacent tissues, and of the cell lines examined, HMGB1 was highest in SCC-9 cells. Additionally,HMGB1 silencing decreased SCC-9 cell proliferation and viability. Down-regulation of HMBG1 expression inhibitednot only the proliferation but also the invasion of SCC-9 cells. The expression of N-cadherin, Snail, and Slug, but notE-cadherin, were promoted after silencing HMGB1. The expression of HMGB1 in OSCC tissue and cell lines washigher, and HMGB1 silencing decreased SCC-9 cell proliferation and invasion, suggesting that HMGB1 has positiveeffects on OSCC development. Down-regulation of HMBG1 expression regulates EMT markers, suggesting thatHMBG1 promotes OSCC cell proliferation and invasion is likely to be associated with EMT activation.