Expression of genes involved in chemoresistance, proliferation and apoptosis in clinical samples of renal cell carcinoma and correlation with clinical outcome.

This study investigated the multidrug resistance, proliferation and apoptosis expression in renal cell carcinomas compared to adjacent normal kidney (ANK) tissues. Multidrug resistance (MDR1), multidrug resistance-associated protein (MRP), glutathione-S-transferase-pi (GST-pi), Topoisomerase-II alpha (TOPO-IIalpha), thymidylate synthase (TS), thymidine kinase (TK), Ki67, BAX and BCL-2 genes were analysed in a series of 30 renal cell carcinomas (RCC) and 16 biopsies from adjacent normal kidney (ANK) tissue using reverse-transcription-PCR (rt-PCR). The mean MDR1 expression was significantly lower in RCC than that of ANK (0.4 +/- 0.2 sd versus 0.75 +/- 0.19, p = 0.0008). The expression of MRP, GST-pi and TOPO-IIalpha was not significantly different in RCC as compared with ANK. The mean TK expression in RCC was significantly higher than in ANK (0.31 +/- 0.15 versus 0.09 +/- 0.08, p = 0.002). The TS and Ki67 expression in RCC was significantly higher than in ANK (87.5%, IC95% 71-100% versus 0%, p = 0.001; 56% IC95% 32-81% versus 0%, p = 0.004, respectively). BAX and BCL-2 expression in RCC was significantly higher than that of ANK (0.51 +/- 0.08 versus 0.18 +/- 0.12, p = 0.0001; 0.73 +/- 0.16 versus 0.5 +/- 0.22, p = 0.01, respectively). No significant correlation was found between MDR1, MRP, GST-pi, TOPO-IIalpha, TS, TK and BAX expression with the grade and the clinical stage in RCC.