Iranian Journal of Medical Sciences (Mar 2010)
Analysis of TP53 Codon 72 Polymorphism in Mucinous and Non-Mucinous Colorectal Adenocarcinoma in Isfahan, Iran
Abstract
Background: The tumor suppressor gene TP53 (alias p53)located on chromosome 17 is involved in various cancers.Case-control studies have shown that p53 codon 72 polymorphismmodulates the prognosis and susceptibility to variousmalignancies. We undertook the present study to explore apossible association between mucinous and non-mucinousadenocarcinomas with different genotypes or alleles at codon72 of TP53.Methods: The genotype distribution and allelic frequenciesfor p53 polymorphism was assessed in 46 and 134 specimensfrom patients with colorectal mucinous and non-mucinousadenocarcinomas, respectively, by using allele-specific PCR.Results: The PCR products were 177bp for proline allele and141bp for arginine allele. In the mucinous samples, the genotypedistribution for p53 polymorphism showed 63%, 23.9%,and 13.1% for the Arg/Arg, Arg/Pro, and Pro/Pro genotypes,respectively. In the non-mucinous specimens 32.1% of thecases were Arg/Arg, 48.5% Arg/Pro, and 19.4% pro/pro. A significantdifference between the two types of adenocarcinomasfor the Arg 72 Arg genotype compared with (grouped) Arg 72Arg and Pro 72 Pro genotypes was noted [OR=3.61 (1.76-7.27),P<0.001]. The arginine allele was found more often in patientswith mucinous adenocarcinoma [OR=1.85 (1.07-3.19), P<0.03].A higher portion of Dukes stage C was noted in the mucinousspecimens (P<0.02) and also mucinous specimens were seenmore often at advanced TNM stages (P=0.01).Conclusion: The Arg/Arg genotype at p53 codon 72 is moreprevalent in mucinous colorectal carcinoma and the arginineallele may contribute to mucinous carcinogenesis. The prolineallele was associated with higher Duke's staging in nonmucinousadenocarcinoma.
