Associations of TP53 mutations, codon 72 polymorphism and human papillomavirus in head and neck squamous cell carcinoma patients

Abstract

To investigate the possible associations between mutations in TP53 and phenotypes of single-nucleotide polymorphisms (SNPs) in codon 72 (SNP72) with the expression profiles of p53 and human papillomavirus (HPV) infection, 93 pathologically diagnosed head and neck squamous cell carcinomas (HNSCCs) were included for study. Using PCR and direct sequencing, 45 TP53 mutations in 35 cases (37.6%) were confirmed out of the 93 HNSCCs. P53 immunohistochemistry (IHC) confirmed 34 (36.6%) cases with positive staining, including 22 cases with strong and 12 with weak positivity. IARC database and software analysis showed similar results that most of the mutated p53 proteins lost their normal function. Further statistical analysis found a negative correlation between p53 IHC and HPV IHC in the tissues from the group of other HNSCCs (of various sites other than the larynx) but not in the tissues from the laryngeal carcinomas. Analyses of SNP72 showed that the patients with the Arg phenotype had a significantly older age at disease onset when compared to patients with the Pro phenotype, particularly in the group of other HNSCCs. In addition, all cases with strong staining for p53 in the laryngeal carcinoma group had the Pro phenotype and all tumors with poor pathological differentiation in the group of other HNSCCs had the Pro phenotype. These data indicate that the profiles of TP53 mutations, SNP72 polymorphism, p53 IHC and HPV E6 IHC are distinct between the groups of laryngeal carcinoma and other HNSCCs.