Overexpression of high mobility group box 1 and 2 is associated with the progression and angiogenesis of human bladder carcinoma

High mobility group box 1 (HMGB1) and HMGB2 overexpression has been observed in several human tumor types, and is involved in cancer progression and prognosis. However, the clinicopathological significance of HMGB1 and HMGB2 expression in bladder carcinoma (BCa), particularly the involvement of these proteins in angiogenesis, remains unclear. In the present study, immunohistochemistry and real-time polymerase chain reaction (PCR) of HMGB1 and HMGB2 in 64 BCa patients revealed that HMGB1 and HMGB2 were overexpressed in BCa tissues compared with normal tissues, and were correlated with tumor clinical stage and pathological grade. In addition, correlation analysis of vascular endothelial growth factor (VEGF) and microvessel density (MVD) counts indicated that the overexpression of HMGB1 and HMGB2 was also correlated with angiogenesis. We conclude that HMGB proteins act as key regulators in the progression and angiogenesis of bladder carcinoma, and serve as potential diagnostic and therapeutic targets.