Expression of p21(WAF1/CIP1) in bladder cancer: Relation to schistosomiasis

Cell cycle regulation Is mediated in part through expression of the cyclin- dependent kinase inhibitor p21(WAF1/CIP1), Loss of p21(WAF1/CIP1) expressio n may, therefore, contribute partially to schistosomal carcinogenesis in th e urinary bladder, We compared p21(WAF1/CIP1) expression in schistosomal an d nonschistosomal bladder cancer to explore possible differences in p21(WAF 1/CIP1) expression between the two subtypes and the possible association be tween schistosomiasis and loss of p21(WAF1/CIP1) expression. Tumor specimen s were obtained from 130 patients who underwent transurethral biopsy or cys tectomy. p21(WAF1/CIP1) was determined by immunodot blot, Western blot, and enzyme immunoassay (EIA), We validated a highly sensitive quantitative EIA assay for determination of p21(WAF1/CIP1) in, cell lysates, Precision, ana lytical recovery, and linearity were all excellent, Our results did not sho w any correlation between p21(WAF1/CIP1) expression and most clinicopatholo gic variables. Lower expression of p21(WAF1/CIP1) was evident in squamous c ell carcinoma (SCC) and schistosomal subtype than in transitional cell carc inoma and nonschistosomal tumors. Our data suggest a potential role for p21 (WAF1/CIP1) alteration in schistosomal carcinogenesis.