Analysis of Association Between MGMT and p53 Gene Single Nucleotide Polymorphisms and Laryngeal Cancer.

ABSTRACT

AIM: To investigate the p53 and O6-methylguanine DNA methyltransferase (MGMT)5' upstream sequence gene promoter regions for single nucleotide polymorphisms and explore the p53 gene 5' upstream sequence consisting of two haplotypes to provide a genetic marker for the incidence of laryngeal squamous cell carcinoma. MATERIALS AND METHODS: We included 96 cases of laryngeal squamous cell carcinoma and 102 controls. We used SNaPshot micro-sequencing analysis of the MGMT promoter region for four single nucleotide polymorphisms and p53 gene 5' upstream sequence loci (rs1625649, rs2287499, rs2287498, rs228749) genotypes. We calculated and compared two groups for genotypic and allelic frequencies, applied HaploView4.2 for computing rs2287499, rs2287498, rs228749 values and haplotype frequencies and tested control loci and Hardy-Weinberg equilibrium. All the experimental data were statistically evaluated using SPSS17.0. The Chi-square test was used for statistical analysis with p<0.05 indicating statistical significance. RESULTS: 5'Upstream single nucleotide polymorphisms rs1625649, rs2287499, rs2287498, rs228749 of p53 were polymorphic in both patient and control groups. There was no statistical significance in frequency distributions for the four loci genotypes when comparing patients and healthy controls (Chi-square values were 4.47, 0.98, 1.67, 4.68, respectively; p>0.05). However, allelic frequencies of the MGMT promoter region locus rs1625649 between patients and healthy control groups were statistically significantly different (chi-square value of 5.77; p<0.05). Differences between allelic frequencies for the p53 gene 5' upstream sequence loci rs2287499, rs2287498 and rs228749 between patients and the healthy control group were not statistically significant (Chi-square values were 1.11,1.56,3.36; p>0.05). Nor were those for the two haplotypes of rs2287499, rs2287498 and rs228749 between patients and the healthy control group were not statistically significant (Chi-square value 1.46, p>0.05). CONCLUSION: MGMT gene polymorphism appears to be associated with the incidence of laryngeal cancer.