Expression oh heat shock protein 70 in renal cell carcinoma and its relation to tumor progression and prognosis
- Autores: Uwe Ramp, C. Mahotka, S. Heikaus, T. Shibata, M.O. Grimm, R. Willers, H.E. Gabbert
- Localización: Histology and histopathology: cellular and molecular biology, ISSN-e 1699-5848, ISSN 0213-3911, Vol. 22, Nº. 10, 2007, págs. 1099-1118
- Idioma: inglés
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Resumen
Summary. Heat shock proteins (HSPs) play an important role in the cellular response to environmental stress and exert a cytoprotective effect. Especially HSP70 is an effective inhibitor of apoptosis, suggesting a role of HSP70 in carcinogenesis and tumor progression. To explore the relevance of HSP70 in renal cell carcinomas (RCCs), we analyzed nuclear and cytoplasmic HSP70 protein expression in formalin-fixed tissue from 145 clear cell RCCs by immuno-histochemistry as well as Western blot analysis.
Nuclear HSP70 expression was found in all RCCs and 75% of the tumors also exhibited a cytoplasmic HSP70 staining. Importantly, RCCs showed significantly reduced cytoplasmic (p=0.001) and combined nuclear/cytoplasmic (p=0.0022) HSP70 expression when compared with their cells of origin. A significant (p=0.0176) decrease of nuclear HSP70 expression became evident from well to poorly differentiated clear cell RCCs. Quite similarly, a trend (p=0.0558) for reduced combined nuclear/cytoplasmic HSP70 expression was shown from early (pT1) to advanced (pT3) tumor stages. Nevertheless, no correlation between HSP70 expression and patients¿ survival became evident.
In conclusion, our investigation demonstrates a significant decrease of antiapoptotic HSP70 protein expression during carcinogenesis and during progression from well (G1) to poorly (G3) differentiated clear cell RCCs. Our results suggest that HSP70-mediated inhibition of apoptosis seems to be of minor importance for carcinogenesis and tumor progression in RCCs. Histol Histopathol 22, 1099-1107 (2007
