High Mobility Group Box 1 (HMGB1) expression in gastric adenocarcinomas

Purpose: High mobility group box 1 (HMGB1), the most important member of the high mobility group box protein family, is a nuclear protein with different functions in the cell; it has a role in cancer progression, angiogenesis, invasion, and metastasis development. The purpose of this study was to investigate the expression of HMGB-1 in gastric adenocarcinoma (GC) and to evaluate its diagnostic and prognostic value. Methods: This study included 85 cases histopathologically diagnosed with GC. Sections obtained from formalin-fixed paraffin-embedded blocks were stained immunohistochemically with HMGB1 antibody. HMGB1 expression was compared with clinicopathologic and prognostic data. Results: HMGB1 expression was negative in 16 (18.8%) patients and positive in 69 (81.2%) patients. There was no correlation between HMGB1 expression and age, sex, histologic subtype of tumor, lymph node involvement (p=0.455, p=0.365, p=0.448, p=0.077, respectively). There was a significant correlation between HMGB1 expression and tumor grade, local invasion depth (T stage) and pTNM stage (p=0.016, p=0.022, p=0.015, respectively). Conclusion: It was found that in the presence of HMGB1 expression, the grade of tumor differentiation decreased and the depth of invasion increased, which was associated with higher stage. These findings suggest that HMGB1 is an independent prognostic factor for GC.