Association of IL-22 and IL-22RA1 gene variants in Iranian patients with colorectal cancer

AIM: In the current study, it was hypothesized that single nucleotide polymorphisms (SNPs) in the regulatory region of the IL-22 signaling pathway genes, including IL-22 and IL-22RA1 variants, may be associated with CRC susceptibility. BACKGROUND: The important role of pro-inflammatory cytokines during tumorigenesis is well-established. In recent years, IL-22 has been linked with colorectal cancer (CRC) through a number of mechanistic and observational studies METHODS: The association of four polymorphisms in the IL-22 (rs1179251 and rs1179246) and IL-22RA1 (rs4648936 and rs10794665) genes with CRC risk were studied using a case-control design with 304 cases and 345 controls from the Iranian population. All 649 subjects were evaluated by PCR–RFLP method. RESULTS: No significant difference was found in genotype and allele frequencies between the cases and controls for either IL-22 and IL-22RA1 gene variants or CRC risk before or after adjusting for confounders. CONCLUSION: The current findings do not present any significant evidence for associations between variants in IL-22 signaling pathway genes and CRC. Complementary studies with greater sample sizes may be necessary to fully elucidate the nature of these associations.