北京地区汉族人群DNA修复基因XPD单核苷酸多态性与肺癌及食管癌风险的研究

目的：研究核苷酸切除修复基因XPD单核苷酸多态性与北京地区汉族人群肺癌及食管癌风险的关系。方法：采用以医院患者为基础的病例－对照研究方法，包括正常对照383人，肺癌患者351例，食管癌患者325例。以聚合酶链反应－限制性片段长度多态性方法分析了XPD基因Asp312 Asn和Lys751Gln多态性，比较不同基因型与肺癌及食管癌风险的关系，并探讨吸烟与基因多态交互作用对患癌风险的影响。结果：与携带312 Asp/Asp基因型者比较，携带至少1个312Asn等位基因者（即Asp/Asn和Asn/Asn基因型）罹患肺鳞癌的风险增加1．8倍（95％CI1．10－2．93），而与肺腺癌无关（校正的比值比为1．07，95％CI0．55－2．08）。分层分析显示，风险型等位基因312Asn和751Gln与吸烟有明显的交互作用。吸烟剂量≥29包／年且携带312Asn或751Gln者罹患肺鳞癌的风险最高，校正的比值比分别为12．44（95％CI4．97－31．17）和10．74（95％CI4．51－25．57）。XPD基因Asp312Asn和Lys751Gln多态与食管鳞癌风险无关。结论：XPD基因Asp312Asn和Lys751Gln多态是地区汉族人群肺鳞癌遗传易感因素，而与肺腺癌以及食管鳞癌风险无关，可能反映了不同组织学类型肺癌以及肺癌和食管癌之间的病因学差异。

Association of genetic polymorphisms in the DNA repair gene XPD with risk of lung and esophageal cancer in a Chinese population in Beijing

OBJECTIVE: XPD polymorphisms at Asp312Asn and Lys751Gln sites have been shown to modulate DNA repair capacity. The authors therefore assessed the relationship between these XPD polymorphisms and susceptibility to lung and esophageal cancer in a Chinese population via a hospital-based, case-control study. METHODS: Genotypes were determined by PCR-restriction fragment length polymorphism approaches in 383 healthy controls, 351 patients with lung cancer, and 325 patients with esophageal squamous cell carcinoma (SCC). The adjusted odds ratios (OR) and 95% confidence intervals (CI) were calculated using multivariate logistic regression. RESULTS: Individuals carrying at least one 312Asn variant allele (Asp/Asn and Asn/Asn genotypes) were at an increased risk for lung SCC as compared with those with the Asp/Asp genotype (OR 1.80; 95% CI: 1.10-2.93; adjusted for age, sex and smoking), but this increased risk was not observed among patients with adenocarcinoma of the lung (adjusted OR: 1.07; 95% CI: 0.55-2.08). Furthermore, stratified analysis indicated a multiplicative interaction between tobacco smoking and the variant XPD 312Asn and 751Gln alleles on risk of lung SCC. The ORs of lung SCC for the variant XPD 312Asn and 751Gln alleles with smoking>or=29 pack/year were 12.44 (95% CI: 4.97-31.17) and 10.74 (95% CI: 4.51-25.57), respectively. No significant association between the Asp312Asn or Lys751Gln polymorphism and the risk of esophageal cancer was found. CONCLUSION: The above findings indicate that the Asp312Asn and Lys751Gln polymorphisms in the XPD locus are associated with the risk of lung SCC but not lung adenocarcinoma or esophageal SCC in this Chinese population.