Introduction :Interleukin-6 (IL-6) encodes a cytokine protein, which causes inflammation, maintains immune homeostasis and plays an essential role in oral pathogenesis. The aim of this study was to evaluate the association between IL-6 (−174 and −572) G/C promoter gene polymorphismsand risk of Oral pre cancer and cancer among Indians.
Methods:Single nucleotide polymorphismin IL-6 genes was genotyped in Oral pre cancer and cancer patients and healthy controls by PCR-RFLP method. Genotype and allele frequencies were analyzed by chi-square test and strength of associations by odds ratio with 95% confidence intervals.
Results:There were significant differences in the GC genotype and C allele frequencies of the IL-6 (−174) G/C gene polymorphism between Oral pre cancer and cancer patients and controls. The difference between Oral pre cancer and cancer patients and controls was statistically significant in homozygous GG and heterozygous GC genotype (OR: 0.5824, CI: 0.3963–0.8559; p: 0.0077*) and homozygous GG and CC genotype (OR: 0.3983, CI: 0.1804–0.8791; p: 0.0316*). C allele was also significantly increased, as compared with the G allele [OR: 0.5894, CI: 0.4349−0.7987; p: 0.0008*]. The genotype GC and C allele frequencies of the IL-6 (−174) G/C gene polymorphism with oral submucous fibrosis and malignancy, was significantly associated with oral pre cancer and cancer. However, frequency of IL-6 (−572)G/C gene polymorphism was not significantly associated with Oral pre cancer and cancer patients (p N 0.05).
Conclusion:The genotype GC and allele C of IL-6 (−174) G/C gene polymorphism play a significant role in Oral pre cancer and cancer susceptibility but IL-6 (-572) G/C gene polymorphism was not significantly associated with oral pre cancer and cancer.
Keywords: Interlukin, PCR-RFLP, Oral pre cancer and cancer, Gene polymorphism.