DNA序列分析对慢性萎缩性胃炎细胞因子基因多态性分布的研究

Application of DNA sequence analysis in the research of distribution of cytokine gene polymorphisms in patients with chronic atrophic gastritis

目的:应用DNA测序方法精确分析几种胃癌易感性相关细胞因子基因单核苷酸多态性(single nucleotide polym orphisms,SNPs)在慢性萎缩性胃炎患者中的分布情况。方法:选择胃癌易感性相关基因SNPs位点,白细胞介素(IL)-1B、干扰素-γ(IFN-γ)、脂磷壁酸(LTA)、IL-8、IL-10、肿瘤坏死因子-α(TNF-α)及巨噬细胞移动抑制因子7个基因上12个SNPs位点,设计、筛选引物。对49例慢性萎缩性胃炎患者的全血DNA,选定引物、PCR扩增,产物纯化后进行Sanger法测序检测IL-1B-31/-511位点SNPs,其中20例患者同样方法检测其余10个SNPs位点序列。结果:IL-1B-31/-511位点各等位基因的频率分别为54.1%、45.9%,各基因型百分率均为30.6%、46.9%、22.4%;其中20例患者其他10个位点各等位基因的平均频率分别为(65.3±26.0)%、(34.8±26.0)%,各基因型平均百分率分别为(49.5±33.0)%、(31.5±18.9)%、(19.0±20.9)%。结论:慢性萎缩性胃炎患者中携有多个胃癌易感性相关细胞因子基因SNPs,为进一步较为全面地研究胃癌易感性基因SNPs在胃癌发生中的分子机制提供基础。

Objective To analyze the distribution of single nucleotide polymorphisms of several genes related to gastric cancer in patients with chronic atrophy gastritis. Methods 12 SNPs in IL-1B, IFN-γ, LTA, IL-8, IL-10, TNF-α, and MIF genes were selected from public databases and published papers, and then were amplified by PCR. Prime sequences used for PCR were designed and selected. DNA was abstracted from peripheral blood in 49 patients with chronic atrophy gastritis, of whom IL-1B-31/-511 SNPs were detected by Sanger DNA sequencing. 20 out of 49 patients were screened for the left 10 SNPs by the same way. Results The frequencies of IL-1B-31/-511 alleles were 54.1% and 45.9%, and the percentages of genotypes were 30.6%, 46.9%, and 22,4%. The average frequencies of alleles of the left 10 SNPs in 20 patients were （65.3 ± 26.0）% and （34.8 ± 26.0）%, and the average percentages of genotypes were （49.5 ± 33.0）%, （31.5 ± 18.9）%, and（19.0 ± 20.9）%. Conclusion Many SNPs of cytokine genes associated with gastric cancer are found in patients with chronic atrophy gastritis.