Association of interleukin-22 gene polymorphism with colon cancer

Abstract:

Objective：To investigate the association of interleukin-22（IL-22） gene polymorphism with colon cancer in the Chinese population，since IL-22 is a member of the interleukin-10 family produced by T cells and innate lymphocytes and is closely associated with the development of inflammation and tumor. Methods：A case-control study was conducted in 540 patients with colon cancer and 540 healthy controls. 5’-Exonuclease assay was used to analyze the three common polymorphisms of the IL-22 gene，i.e.，-429 C/T，+1046 T/A，and +1995 A/C. The Pearson chi-square test was used for comparison of categorical variables，and the Student’s t-test was used for comparison of continuous variables. Results：In the patients with colon cancer，there were significant increases in the frequen－cies of IL-22 -429 TT genotype（odds ratio[OR]=1.69，95% confidence interval[CI]：1.24-2.30，P=0.001） and -429 T allele（OR=1.35，95%CI=1.14 to 1.60，P=0.001）；there were still significant differences after Bonferroni correction（P<0.017）. The further stratifi－cation analysis showed that the patients with poorly differentiated colon cancer had a significantly higher frequency of IL-22 -429 TT genotype than those with moderately differentiated or well-differentiated colon cancer（OR=1.45，95%CI=1.02 to 2.07，P=0.04０），while the polymorphism of IL-22 -429 C/T was not associated with the location，tumor size，growth pattern，and TNM stage of colon cancer. The polymorphisms of IL-22 +1046 T/A and IL-22 +1995 A/C were not associated with colon cancer（P=0.98０ and 0.75０）. Conclusion：The polymorphism of IL-22 -429 C/T may be associated with colon cancer.