Distribution of IL-1β and IL-1RN intron2 gene polymorphism in colorectal cancer of Chinese Han people in Shandong area

Abstract

Objective To study the distribution characteristics of IL-1β-31/-511 single nucleotide polymorphisms(SNPs) and IL-1RN intron2 variable number of tandem repeat (VNTR) of Chinese Han people with colorectal cancer in Shandong area. Methods The IL-1β-31/-511SNP in a total of 490 colorectal cancers were determined by using gene chip. The VNTR were investigated by using PCR- RFLP.The sera concentrations of IL-1β/-1ra were measured by ELISA. The relationship between IL-1β- 31/-511SNP or IL-1RN VNTR and colorectal cancer group in 490 cases were analyzed by case-control study.χ2 or t test was used to compare the results of relevant index. The relative risk degree was estimated by odds ratio (OR) and 95% confidence interval (95%CI). Results The ratio of IL-1ra/IL-1β was significantly lower than that of the control group (u=-23, P<0.01). Frequencies of IL-1β-511TT(P<0.05, OR=1.55, 95%CI=1.10-2.18)and T allele (P<0.05, OR=1.31, 95%CI=1.05-1.63)in patients with colorectal cancer were significantly higher than that in controls correspondingly. -511TT and T frequency in rectal cancer or tubular adenocarcinoma was significantly higher than control group, The ORs (95%CI) appeared to be 1.59 (1.03-2.45), 1.74 (1.19-2.55) and 1.39(1.04-1.86), 1.42(1.10-1.83)respectively.In poorly differentiated tubular gland cancer group, -511TT frequency (61.90%)was higher than that of the control group. In contrast, the frequency of CT (19.05%) was on the opposite tendency of TT. The ORs (95%CI) appeared to be 4.57 (1.96-10.65) and 0.23 (0.08-0.64) respectively. -511T frequency of moderate or low differentiated group of tubular gland cancer were significantly higher than the control group, The ORs (95%CI)appeared to be 5.80 (1.24-27.08) and 235 (1.24-4.59), respectively area. Conclusion IL-1β-511C/T SNP is associated with the occurrence and development of colorectal cancer of Chinese Han people in Shandong area. Key words: Colorectal neoplasms; Interleukin-1 beta; Polymorphism, single nucleotide