Association of Two Polymorphic Codons in P53 and ABCC1 Promoter with Prostate Cancer

In prostate cancer, mutated p53 alleles typically contain missense single-base substitution in codon 72 that resides within exons 5-8. Stable p53 proteins in tumor cell nuclei have been associated with malignancy. A role of p53 is the regulation of drug transporters like ABCC1 (MRP1) by an effect on promoter region.

The objective of this study was to identify association of mutations of p53 at codon 72 and 282 and promoter region of ABCC1 with increased risks of prostate cancer.

Formalin fixed, paraffin-embedded malignant tissues of 45 patients and 45 control samples were evaluated. PCR-RFLP using BstUI for codon 72 and HpaII restriction enzyme for codon 282 p53 gene, and G-1666A promoter region of ABCC1 gene was performed. To assess the frequency of these mutations and to detect new mutations in cancerous samples, PCR-SSCP analysis was performed.

The frequencies of CC, GC and GG genotypes of codon 72 of p53 were 33.33%, 46.67% and 20.00% in patients with cancer and 15.56%, 48.89% and 35.55% in controls, respectively. The relative allele frequencies of ABCC1 promoter polymorphism were 60.00% A and 40.00% G in patients as opposed to 37.78% for A and 62.22% for G in controls. Genotypic frequencies of p53 codon 72 and G1666A of ABCC1 in patients vs. Controls were statistically significant(p<0.05). The study of these samples with PCR-SSCP displayed some new banding patterns.

The present findings suggest that CC homozygosity in codon 72 of p53 gene and AA genotype in G-1666A of ABCC1 gene may play a role in combination in prostate cancer and increased susceptibility for this malignancy in the Iranian Kurdish population.