Expression of HMGB1/RAGE protein in renal carcinoma and its clinical significance

Objective: To investigate the expression of high mobility group protein B1 (HMGB1) and its receptor, receptor for advanced glycation end-product (RAGE), in renal cancer tissue and surrounding normal tissue and to analyze the relationship between the expression level of the protein and receptor as well as the clinical pathological characteristics and prognosis in renal cancer patients. Methods: A total of 80 renal carcinoma patients who were surgically treated in our hospital from February 2004 to December 2012 were included in this study. Normal paratumoral tissues were collected as a control. All diagnoses were confirmed with a postoperative pathological examination. All patients had complete pathological data. The expression of HMGB1/RAGE proteins in renal cancer tissue and paratumoral tissue was examined using immunohistochemical methods. Results: The positive expression rate of HMGB1 was 71% in renal cancer tissue, which was significantly higher than that in the paratumoral normal tissue (25%). The positive expression rate of RAGE was 72% in renal cancer tissue, which was significantly higher than that in the paratumoral normal tissue (27%). Further analysis did not indicate a correlation between the positive expression of HMGB1 and RAGE proteins and gender, age and tumor size (P > 0.05), whereas the expression patterns were shown to correlate with tumor differentiation, clinical stage and lymph node metastasis (P < 0.05). The expression of HMGB1 exhibited a significant positive correlation with RAGE level (P < 0.05), the expression of HMGB1/RAGE proteins exhibited a negative correlation with the prognosis of patients, and the five-year survival rate of patients with positive expression was significantly lower than that of patients with negative expression (P < 0.05). Conclusion: HMGB1/RAGE exhibited significantly elevated expression in renal cancer tissues that was closely related to the clinical prognosis of patients; thus, the expression levels may become a new target in the treatment of renal carcinoma.