Interleukin 22 polymorphisms and papillary thyroid cancer.

Abstract

IL22RA1 (Interleukin 22 receptor-alpha 1), a member of the class II cytokine receptor family, mediates diverse biologic activities and appears to be important in pathogen defense, wound healing, and tissue reorganization. Polymorphisms in genes encoding inflammatory cytokines are associated with increased cancer risk. The aim of this study was to evaluate the association between the single nucleotide polymorphisms (SNP) in the IL22 and IL22RA1 and papillary thyroid cancer (PTC), and to assess the relationship between the SNP in the IL22 and IL22RA1 and the clinical parameters of PTC. Study enrolled experimental group of 94 PTC patients and 213 controls. PTC patients were grouped and compared for clinical PTC parameters. One promoter SNP of IL22, -429C/T (rs2227485), and one SNP of IL22RA1, Arg518Gly (rs3795299) were analyzed using direct sequencing. Genetic data were analyzed using Helixtree, SNPAnalyzer Pro, SNPStats, and Haploview. A SNP in IL22 (rs2227485) was significantly associated with PTC (codominant2 model [C/C vs T/T], odds ratio (OR) 2.39, 95% confidence interval (CI) 1.21-4.71, p=0.012; dominant model, OR 1.89, 95% CI 1.08-3.31, p=0.022). The allele T frequency of rs2227485 in IL22 was also associated with PTC (OR 1.59, 95% CI 1.13-2.25, p=0.009). According to clinical parameters, rs2227485 of IL22 was associated with number of cancers (dominant model, OR 3.03, 95% CI 1.02-9.01, p=0.035). By haplotype analysis, TG was associated with PTC (codominant model, OR 1.52, 95% CI 1.07-2.16, p=0.019; dominant model, OR 1.91, 95% CI 1.13- 3.24, p=0.015). Genotype and allele analysis of rs3795299 in IL22RA1 showed no significant differences between PTC patients and controls. The rs2227485 SNP in IL22 might be associated with the risk and the multifocality of PTC.