P21/WAF1 and cyclin D1 variants and oral squamous cell carcinoma

BACKGROUND: Genetic factors are known to be involved in oral squamous cell carcinoma (OSCC) development. METHOD: We evaluated a possible association between CCND1 A870G and P21/WAF1 C98A polymorphisms and OSCC, as well as the impact of the genotypes on protein immunoexpression. The study group consisted of 80 individuals with histopathological diagnosis of OSCC and the control group consisted of 80 healthy individuals without oral lesions and matched by age, sex and tobacco usage. The genotypes were studied by the polymerase chain reaction and restriction fragment length polymorphic analysis. Paraffin-embedded sections were used for immunohistochemical analysis. RESULTS: No statistical association between CCND1 and/or P21/WAF1 genotypes and OSCC was demonstrated, although we found that people harbouring the combined presence of at least one variant allele of both genes showed a 1.8 times more chance of developing OSCC compared to the referent genotype. OSCC tumours from individuals with P21 heterozygous genotype showed a significantly higher immunopositivity than tumours from wild-type individuals. CONCLUSION: The present study did not demonstrate a significant association between CCND1 and/or P21/WAF1 genotypes and OSCC. However, P21 protein expression in OSCC tumours is affected by P21/WAF1 genotype.