High-mobility group box 1 is involved in the development of benign prostatic hyperplasia with chronic prostatic inflammation

Abstract

Objective. The aims of this study were to explore the role of high-mobility group box 1 (HMGB1) in benign prostatic hyperplasia (BPH) and to perform a preliminary investigation of the mechanisms underlying BPH. Materials and methods. HMGB1 expression in 160 BPH cases was analyzed using immunohistochemistry. HMGB1 expression in primary prostate epithelial cells and the concentration of HMGB1 in the surrounding culture medium were detected by Western blotting and enzyme-linked immunosorbent assay, respectively. Cell proliferation was evaluated by the carboxyfluorescein succinimidyl ester (CFSE) dilution assay. Student’s t test or a one- or two-way analysis of variance test, followed by Bonferroni post hoc analysis, were used to test differences between groups and time-course data. Results. HMGB1 expression was higher in BPH with prostatitis than in BPH alone and was positively correlated with prostate volume in BPH patients with prostatitis, but not in BPH patients without prostatitis. HMGB1 expression in primary prostate epithelial cells as well as its release into the extracellular environment increased when the cells were treated with the proinflammatory molecule lipopolysaccharide (LPS). In addition, HMGB1 overexpression promoted the proliferation of primary prostate epithelial cells under LPS stimulation, and this could be inhibited by the HMGB1 antagonist boxA. Conclusions. These findings provide novel insights into the pathogenic role of HMGB1 in BPH with prostatitis, and suggest that HMGB1 is a potential biomarker and therapeutic target for BPH.