Cyclin D1 gene polymorphism as a risk factor for oral premalignant lesions.

BACKGROUND Deregulation of cell cycle plays an important role in tumorigenesis. Cyclin D1 gene (CCND1) is a key regulator of the G(1) phase of the cell cycle. METHODS In this case-control study of 115 oral premalignant lesion (OPL) patients and 230 controls, we genotyped the CCND1 single nucleotide polymorphism (SNP) at the exon 4 splice site (G870A) and determined the association of this SNP with the risk of developing OPLs. RESULTS We found significant associations between the heterozygous variant allele (GA), the homozygous variant allele (AA) and OPL risk, with adjusted odds ratios (ORs) of 1.91 [95% confidence interval (CI), 1.05-3.48] and 2.38 (95% CI, 1.16-4.87), respectively. The OR for individuals with at least one variant allele was 2.04 (95% CI, 1.15-3.60). When further stratified analyses were performed, the increased risk was more evident in younger individuals (OR = 2.82; 95% CI, 1.32-6.02), in men (OR = 2.97; 95%CI, 1.31-6.71) and in never smokers (OR = 2.92; 95% CI, 1.09-7.82). Finally, we found joint effects between the variant alleles and the smoking status. Using never smokers with the wild-type (GG) genotypes as the reference group, the ORs for never smokers with the variant genotypes (G/A + A/A), smokers with the G/G genotype and smokers with the G/A + A/A genotypes were 2.92 (1.09-7.82), 3.95 (1.36-11.5) and 7.01 (2.68-18.4), respectively. CONCLUSION Our results suggest that the CCND1 G870A SNP may contribute to genetic susceptibility to OPLs and involve in oral cancer development.