Expression of heat shock proteins 27 and 70 in renal cell cancer and normal renal tissue:: An immunohistochemical study

Background: There is increasing evidence that heat shock proteins (HSP) 27 and 70 are expressed in a variety of cancers, having an impact on prognosis and drug resistance. Little is known regarding the expression of HSPs in urological tumors. Therefore, we investigated whether the expression of HSP27 and HSP70 in renal cell cancer differs from normal renal tissue and is related to tumor stage and grade, cell type and patient survival. Patients and Methods: Apart from histopathological evaluation, deparaffinized sections of 12 renal cell carcinomas and 2 subsequent secondaries were immunostained using the biotin-streptavidin complex system after incubation with a mouse anti-human IgG(1) against HSP27, HSP70 and HSC70. The patients entered a routine follow-up. Results: No correlation was found between HSP-expression and tumor stage and grade. In 3 patients with renal cell cancer who developed local progression or systemic disease, staining for HSP70 was either negative or weak. In contrast to normal renal tissue staining for HSP, renal cell cancer did not uniformly express HSP27 and HSP70. Conclusion: With respect to the number of cases investigated, immunohistochemical expression of HSP27 and HSP70 has probably neither diagnostic nor prognostic significance in renal cell cancer. It remains to be studied in a larger cohort whether the expression of HSP70 may possibly correlate with the clinical course of the disease.