IL-10 gene promoter and intron polymorphisms as genetic biomarkers of cervical cancer susceptibility among Tunisians

Abstract

Abstract Objective We investigated the association between polymorphisms in the promoter and intron regions of the interleukin-10 (IL-10) gene with the risk of cervical cancer (CC) in Tunisian patients and control women.

Methods Study subjects comprised 86 CC cases and 126 control women. Genotyping of IL-10 intron (rs3024491, rs3024490) and promoter (rs1800872, rs1800871, rs1800896) variants was done by real-time PCR, with defined clusters.

Results The minor allele frequencies of the five tested IL-10 SNPs were not significantly different between cervical cancer cases and control women. However, significantly higher frequencies of homozygous minor allele-carriers in cases was seen for rs3024490 (P = 0.023), rs1800872 (P = 0.037), and rs1800871 (P = 0.028). IL-10 serum levels were significantly reduced in rs3024490 T/T vs. G/G genotype carriers, and in rs1800871 T/T than C/C genotype carriers. While carriage of rs1800872 and rs3024491 minor allele was associated with reduced IL-10 secretion, this was not statistically significant. Haploview analysis demonstrated high linkage disequilibrium (LD) among the IL10 SNPs studied, and only seven haplotypes were common, capturing 98.8% of the total possible haplotypes. Reduced frequency of haplotypes GTCCA (P < 0.001) and TGATG (P < 0.001) was seen in cervical cancer cases than in control women, thus conferring disease protection nature to these haplotype. This association remained significant for GTCCA (Pc = 0.006) and TGATG (P = 0.045) after correcting for multiple comparisons.

Conclusion Specific IL-10 variants (rs3024490, rs1800872, and rs1800871) and haplotype (GTCCA and TGATG) may contribute to the development of cervical cancer among Tunisian women.