Genetic variation in interleukin-10 gene and risk of oral cancer

BACKGROUND: Common genetic variants in immune and inflammatory response genes can affect the risk of developing oral cancer. Interleukin-10 (IL-10) is an immunosuppressive cytokine which may facilitate development of cancer by supporting tumor escape from the immune response. Inter-individual variations in IL-10 production were genetically contributed to polymorphisms within IL-10 promoter region. We determined whether single nucleotide polymorphisms (SNPs) at positions -1082 A/G (rs1800870), -819 T/C (rs1800871) and -592 A/C (rs1800872) in the IL-10 gene promoter were involved in predisposing an individual to oral cancer. METHODS: We analyzed 3 SNPS of IL-10 gene promoter in 280 patients with oral cancer and 300 age and sex matched controls in a Chinese population, using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) strategy. RESULTS: There were significant differences in the genotype and allele distribution of -1082 A/G (rs1800870) polymorphism of the IL-10 gene among cases and controls. The -1082 G alleles carriers were associated with a significantly increased risk of oral cancer compared with the non-carriers (OR=1.821, 95% CI, 1.329-2.496, P<0.001). Haplotype analysis revealed that the GCC haplotype (defined by SNPs at positions -1082, -819 and -592) of IL-10 gene conveys the highest risk for oral cancer compared with the ATA haplotype (OR=1.716; 95% CI, 1.230-2.395; P=0.001). CONCLUSION: IL-10 gene promoter -1082 A/G (rs1800870) polymorphism, and its haplotype are significantly associated with the risk of oral cancer. Our data suggests that IL-10 gene plays an important role in the development of oral cancer.