ABSTRACT
GSH and GST activity were measured in eleven human bladder tumor and adjacent uninvolved specimens obtained from Egyptian patients with a history of schistosomal infection, undergoing cystectomy. The expression of GST[pi] was also measured using Western blotting analysis. GSH was higher in the tumor than in surrounding uninvolved tissue, though the difference was not significant. Total GST activity and GST[pi] expression were significantly higher [p < 0.05] in tumor tissues than in uninvolved tissues. There was a positive correlation between GST activity and GSH content in tumor tissues [r=0.64, p < 0.0005] and in surrounding uninvolved tissues [r = 0.72, p < 0.001]. A good correlation was also observed between total GST activity and GST[pi]expression in both tumor [r = 0.75, p < 0.05] and uninvolved tissues [r = 0.86, p<0.01]. To our knowledge, this is the first report of GST activity and GSH content in bladder cancer tissues associated with schistosomiasis. Our results suggest that one mechanism of resistance of this tumor to DNA interacting agents might be related to their inactivation by the GSH/GST system