p21 is a cyclin-dependent kinase inhibitor that is pivotal in arresting cellular growth, in terminal differentiation and in apoptosis. Two polymorphisms in the p21Waf1/Cip1gene, i.e., codon 31 in the coding region and 3’UTR, have been identified and appeared to influence the expression of p21Waf1/Cip1. Several epidemiologic studies have examined the effect of these polymorphisms on cancer risk, which has motivated us to study the relationship between p21 codon 31 and 3’UTR polymorphism and the risk of prostate cancer among a sample population of Kurdistan province of IRAN. Genotyping was done by PCR-RFLP using DNA from (i) 45 prostate cancer paraffin embedded tissues, and (ii) a total of 30 normal blood samples. The PCR-RFLP products were 169bp for C allele, 115bp and 54bp for A allele in codone 31 and were 191 bp for C allele, 76bp and 115bp for T allele in 3’UTR. Frequencies of C/C and C/A plus A/A genotypes in 31 codone, were 31 (68.8%), 14 (31.2%) in carcinoma cases and 18 (60.0%), 12 (40.0%) in control cases, respectively. Allelic frequencies for controls were 0.866 for C and 0.124 for A and for patients were 0.84 and 0.16 for C and A respectively. For 3’UTR the only observed genotype were C/C for both control and cases. Although the sample size is relatively small, these findings suggest that a codon 31 polymorphism in p21 may be associated with the development of prostate cancer.
