CYP1A1 activity in renal cell carcinoma and in adjacent normal renal tissue

Abstract

Cytochrome P450-isoenzyme, CYP1A1, is responsible for the metabolic activation of several precarcinogenic environmental chemicals to their carcinogenic intermediates. Microsomal CYP1A1 activity in renal cell carcinoma (RCC) and in normal renal tissue was determined by measuring spectrofluorometrically the hydroxylation rate of benzo[a]pyrene. The study included 50 patients who underwent nephrectomy for RCC. Tissue specimens were taken from renal tumours and, as a control, from macroscopic normal renal tissue adjacent to the tumours. Normal renal tissues that were adjacent to poorly differentiated grade 3 tumours and/or to metastatic RCC contained significantly higher CYP1A1 activities than renal tissues next to well-differentiated (P = 0.02) and/or organ-confined tumours (P = 0.001). In conclusion, those patients who had tumours that could be considered aggressive on the grounds of poor cell differentiation or a metastatic feature of tumour, had remarkably higher CYP1A1 activities in their kidneys than the patients with less aggressive renal tumours.