Association of interleukin-6 genetic polymorphisms with risk of OSCC in Indian population

Abstract

Purpose: 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 polymorphisms and risk of OSCC among Indians.

Methods: Single nucleotide polymorphism in IL-6 genes was genotyped in OSCC 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: Frequency distribution of IL-6 (- 174) G/C gene polymorphism was significantly associated with OSCC patients in comparison to healthy controls (OR: 0.541, CI: 0.356-0.822; p: 0.004. However, frequency of IL-6 (- 572) G/C gene polymorphism was not significantly associated with OSCC patients (p > 0.05).

Conclusion: The genotype GC and allele C of IL-6 (- 174) G/C gene polymorphism play a significant role in OSCC susceptibility.

Keywords: Genotype; Immune response; Inflammation; OSCC; PCR-RFLP.

Fig. 1

PCR-RFLP analysis for IL-6 − 174G/C genotyping. The PCR-amplified product was 300 bp. The fragments after digestion with NlaIII (lanes 1: 100 bp ladder, lanes 2, 4: GG, lanes 3, 6, 8, 9: GC and lanes 5, 7: CC genotype) were obtained.

Fig. 2

PCR-RFLP analysis for IL-6 − 572G/C genotyping. The PCR-amplified product was 163 bp. The fragments after digestion with MbiI (lanes 1: 100 bp ladder, lanes 2, 3, 4, 5, 8, 9: GC, lanes 6, 10, 11: GG and lane 7: CC genotype) were obtained.