Significance of heat shock protein-27 expression in patients with renal cell carcinoma

Abstract

Objectives To investigate heat shock protein (HSP)-27 expression in patients with renal cell carcinoma (RCC) and examine its biologic significance. HSPs were first defined as proteins induced by heat shock and other environmental and pathophysiologic stresses. They are implicated in protein-protein interactions and are thought to play an important role in cancer. The expression of HSP-27 has been demonstrated in some human tumors. Methods The expression of HSP-27 was studied in tumor and normal parenchyma tissue specimens from 76 patients with RCC by immunohistochemistry. The findings were correlated with clinical stage, lymph node metastasis, histologic grade, and survival. Results Of the 76 RCC tissue specimens studied, the presence of HSP-27 was demonstrated in 73 (96%). The expression was low in 10 patients (14%), intermediate in 38 (50%), and high in 25 (33%). HSP-27 expression was greater in RCC tissue compared with adjacent noncancerous renal tissue ( P <0.001). An inverse relationship was found between tumor stage and HSP-27 expression ( r = −0.281, P = 0.016). However, no statistically significant difference was observed in progression-free survival with respect to HSP-27 expression. No relationship was found between HSP-27 expression and tumor grade, lymph node metastasis, distant metastasis, or cause-specific survival. Conclusions Our data suggest that HSP-27 expression is not a powerful and statistically significant prognostic indicator for disease-free survival for patients with RCC.