Expression of multidrug resistance markers ABCB1 (MDR-1/P-gp) and ABCC1 (MRP-1) in renal cell carcinoma
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.