Polymorphisms of the interleukin-6 (IL-6) gene contribute to cervical cancer susceptibility in Bangladeshi women: A case-control study

Abstract

Background and Aims: Cervical cancer is characterized by abnormal cell growth in the lining of cervix and it is the second major cause of cancer-related deaths among females in Bangladesh. Interleukin-6 (IL-6) is a multifunctional cytokine that has been heavily linked with cervical cancer. Our aim was to investigate the association of two promoter single-nucleotide polymorphisms (SNPs) of IL-6 (rs1800795 and rs1800797) with the susceptibility of cervical cancer in Bangladeshi women. Methods: DNA was extracted from venous blood samples from cervical cancer patients (n = 126) and healthy controls (n = 120). Polymerase chain reaction-restriction fragment length polymorphism was used for genotyping of the selected SNPs. Logistic regression was performed to calculate the odds ratio (OR) with 95% confidence interval (CI) and p values. Results: We found a significant association between rs1800795 and rs1800797 polymorphisms and cervical cancer. For, rs1800795 (G > C) the GC heterozygous genotype (OR = 2.80, 95% CI = 1.55–5.07, p = 0.0007) and CC mutant homozygous genotype (OR = 3.5, 95% CI = 1.29–9.51, p = 0.014) conferred an increased risk of cervical cancer. In case of rs1800797 (G > A) polymorphism, the AG heterozygous genotype (OR = 6.94, 95% CI = 3.76–12.81, p < 0.0001) and AA mutant homozygous genotype (OR = 3.88, 95% CI = 1.12–13.51, p = 0.0332) also exhibited an elevated risk of cervical cancer. Use of contraceptives was found as risk factor and patients who smoke were carriers of both the risk alleles and thus had an increased risk of cervical cancer. Conclusion: Our findings suggest that polymorphism of rs1800795 and rs1800797 of the IL-6 gene play a significant role in cervical cancer susceptibility in Bangladeshi women.