XPA基因多态性与食管癌易感性关系的研究

Study on the relationship between polymorphisms of XPA gene and susceptibility of esophageal cancer

目的探讨长治地区食管癌高发的主要环境危险因素和参与DNA损伤修复的XPA基因多态性与食管癌易感性的关系，以及与环境因素之间对食管癌发生的交互作用。方法采用病例对照研究，对196例食管癌患者和201例对照者进行食管癌相关因素的问卷调查，应用PCR—RFLP技术对XPA23G多态性基因型检测，采用SPSS12．0统计软件对研究结果进行分析。结果病例组携带突变（G）等位基因的频率明显低于对照组（x^2=18，31，P〈0．01）；XPA基因三种基因型在两组间差异有统计学意义（x^2=16．56，P〈0．01），且携带有XPA突变杂合子（A/G）和突变纯合子（G／G）的个体发生食管癌的危险性比携带野生纯合子（A/A）个体低[OR值（95％CI）分别为0．58（0．37～0．91）和0．32（0．18～0．56）]。携带XPA突变基因G与经常食用腌制食品之间存在负交互作用（S=0．04，API=-0．77）。结论XPA23G多态性可能与长治地区食管癌的发生有一定关系，携带XPA突变基因G可抑制食用腌制食品对食管癌的发生。

Objective To explore the relationships between the polymorphisms of xeroderma pigmentosum A（XPA） and the susceptibility of esophageal cancer （EC）, as well as its interaction with environmental factors-gene in Changzhi area, Shanxi province. Methods A case-control study was conducted, including 196 cases of EC and 201 controls. XPA 23G polymorphisms were determined with polymerase chain-restriction on fragment length polymorphism （PCR-RFLP）. Results The risk of EC was significantly degraded in the individuals who had been carrying the XPA heterozygote （A/G） and mutation genotype （G/G）, compared to those with wild genotype （x^2 = 16.21, P 〈 0.01） and the ORs were 0.58 （0.37-0.91） and 0.32 （0. 18-0.56）, respectively. There was negative interaction between XPA 23G mutation genotype and the consumption of pickled food （ S = 0.04, API = - 0.77）. Conclusion Genetic polymorphism in the XPA 23G might be associated with esophageal cancer in Changzhi area, and there was a negative action between XPA predisposing genotype and the consumption of pickled food.