DNMT3B基因启动子C46359T多态性与食管癌易感性的关联分析

Evaluating association of DNA methyltransferase 3B gene promoter C46359T SNP with genetic susceptibility to esophageal cancer in a Chinese population

目的：探讨DNMT3B基因启动子C46359T单核苷酸多态性与江苏汉族人群食管癌易感性的关系。方法：提取195例食管癌患者及189例健康体检人员外周血基因组DNA，采用PCR—RFLP结合DNA测序技术检测DNMT3B基因启动子C46359T单核苷酸多态性。结果：正常对照DNMT3BC46359T等位基因TT／CT基因型频率为98．9％／1．1％，病例组为97．9％／2．1％，在对照组与病例组中均未检测到DNMT3B 46359 CC基因型。携带DNMT3B 46359 CT等位基因的个体与对照组相比，其患食管癌的易感性未见明显升高（P=0．43，OR=1．96，95％CI：0．35—10．82）。对比江苏汉族人群和英国、美国白种人群，DNMT3B C66359T单核苷酸多态性频率分布有明显差异（P〈0．01）。结论：DNMT3B基因CA6359T多态性可能不适合作为中国汉族人群食管癌易感性的一个独立风险因素，此位点多态性的分布在不同人种间有显著差异。

Objective To explore the association DNA methyltransferase-3B（DNMT3B） gene promoter single nucleoticle polymorphism（SNP） with the genetic susceptibility to esophageal cancer. Methods Genomic DNA was extracted from the leukocyte cell of each blood samples both in 189 esophageal cancer cases and 195 control subjects. Polymerase chain reaction with restriction fragment length polymorphism （PCR-RFLP）and DNA sequencing analysis were employed to assess the polymorphism of DNMT3B gene promoter C46359T. Results The DNMT3B gene promoter C46359T TT/CT allelic genotype of the control subjects and esophageal cancer was 98.9%/1.1% and 97.9%/2. lifo, respectively. No C/C genotype was found in both of esophageal cancer and control. Individuals with at least one 149C allele were no at a significantly increase risk of esophageal cancer compared with those having a 149TT genotype （P =0.43 ,OR = 1.96,95% CI =0.35 - 10.82）. The distribution of DNMT3B gene promoter C46359T allele in Chinese was distinct from that in British and American（P 〈 0.01 ）. Conclusion The DNMT3B C46359T SNP is inapplicable to be an independent risk factor for the genetic susceptibility of esophageal cancer in Chinese. DNMT3B gene promoter SNP is diverse in ethnic populations.