亚甲基四氢叶酸还原酶基因遗传变异与肺癌

目的探讨亚甲基四氢叶酸还原酶(MTHFR)基因多态与肺癌风险的关系.方法以聚合酶链反应和限制性片段长度多态性分析方法检测505例肺癌患者和500名正常对照者MTHFR C677T和A1298C基因型;用EH软件构建了这两个多态的单体型;以比值比(OR)及其95%可信区间(CI)比较不同基因型的肺癌相对风险度.结果C677T突变等位基因频率在肺癌患者和正常对照者中的分布差异具有显著性(53.5%vs44.9%,P＜0.001).与MTHFR 677CC基因型比较,677CT和TF基因型患肺癌的风险分别增加1.43(95%CI,1.04～1.95)和2.40(95%CI,1.61～3.59)倍.MTHFR基因677T-1298A单体型频率在病例组和对照组中分布差异具有显著性(P＜0.05).未发现MTHFR A1298C基因多态与肺癌风险相关.结论MTHFR基因变异可增加患肺癌的风险.

Association between genetic polymorphisms in methylentetrahydrofolate reductase and risk of lung cancer

Objective To investigate the association between methylentetrahydrofolate reductase (MTHFR)polymorphisms and risk of lung cancer. Methods Totally 505 cases with lung cancer and 500 frequency-matched controls were genotyped for the MTHFR C677T and A1298C polymorphisms by polymerase chain reaction-restriction fragment length polymorphism methods. The odds ratios(OR)and 95% confidence intervals(CI)were calculated using unconditional logistic regression model. Haplotype frequency was estimated using EH software. Results The frequency of the MTHFR C677T allele in cases was significantly higher than that in controls(53.5% vs 44.9%, P < 0.001). Compared with the 677CC genotype, the 677CT and 677TT genotypes were associated with increased risk of lung cancer, with the OR being 1.43(95% CI, 1.04-1.95)and 2.40(95% CI, 1.61-3.59), respectively. In addition, a significant difference in the distribution of haplotype frequencies between cases and controls was observed. Conclusion Functional polymorphism in MTHFR is associated with increased risk of lung cancer in Chinese population.