Surgically induced ischemia has no impact on protein expression levels of HIF‐1α and related biomarkers in renal cell carcinoma

Abstract

The increasing demands for personalized targeted therapy directed against renal cell carcinoma have driven a search for predictive markers. Novel therapies targeting HIF‐1α in renal cell carcinoma have been developed, and HIF‐1α has been suggested as a novel predictive marker of response to therapy. The surgical resection of a kidney tumor induces tissue ischemia, and HIF‐1α is an oxygen‐sensitive transcription factor, which is known to be upregulated during hypoxia. This study investigated the impact of intra‐surgical and post‐surgical ischemia on protein expression levels of HIF‐1α and three related biomarkers (VEGF, GLUT‐1, and CAIX) in 20 patients with renal cell carcinoma with immunohistochemistry and Western blotting. Surgical ischemia did not have a significant impact on protein expression levels of any of the investigated markers. Long‐post‐surgical ischemia resulted in reduced expression levels of HIF‐1α, probably due to autolysis. Our results suggest that HIF‐1α is a stable protein, with expression levels not affected by intra‐surgical ischemia, and hence, HIF‐1α is suited for marker analysis.