致癌物代谢酶基因（CYP2C19、GSTT_1）多态性与哈萨克族人群食管癌发病风险关系的研究

目的探讨、相代谢酶基因多态性与新疆哈萨克族人群食管癌发病风险的关系。方法收集经组织病理学确诊的哈萨克族食管鳞癌新发病例88例外周血液标本,提取DNA后用PCR-RFLP技术检测CYP2C19、GSTT1基因多态性。结果食管癌组和对照组中CYP2C19m1、CYP2C19m2基因各型之间差异无统计学意义（P〉0.05）,但食管癌组S-美芬妥英慢代谢者（PM）的患病率为26.1%,为正常对照组11.1%约2倍多,两者差异有统计学意义（χ2=5.72,P〈0.05,相对危险度OR=2.831,95%可信度CI：1.180～6.793）。GSTT1基因缺失型（-）和正常型（＋）频率在对照组中分别为45.4%和54.2%,在哈萨克族食管癌组中分别为64.8%和35.2%,两组间的频率分布差异有统计学意义（P〈0.05,OR=2.173,95%CI：1.149～4.110）。结论相代谢酶基因CYP2C19在哈萨克族人群中具有遗传多态性,CYP2C19m1和CYP2C19m2是两个相互独立的突变型等位基因,CYP2C19慢代谢者参与了食管癌致癌物的灭活,其活性降低时可增加患食管癌的易感性。相代谢酶基因GSTT1基因缺失型（-）可能是哈萨克族人群患食管癌重要的生物标志。对哈萨克族人群进行、相代谢酶基因分型,有助于筛选食管癌发生的高危人群,可为食管癌的预防和早期诊断提供科学依据。

Study on relations between genetic polymorphisms in CYP2C19,GSTT1 and risk of Kazakh's esophageal cancer in Xinjiang

Objective To determine whether genetic polymorphisms in CYP2C19,GSTT, were associated with the risk of Kazakh＇s esophageal cancer. Methods A hospital-based, case-control study consisting 88 cases of incident Kazakh＇s esophageal squamous carcinoma and 72 controls matched on age,sex and race was conducted to investigate the association between polymorphism in CYP2C19 ,GSTT1 and susceptibility to Kazakh＇s esophageal cancer. Genotypes of CYP2C19 ,GSTTI were analyzed by polymerase chain reasction-restriction fragment length polymorphlsm methods. Results Each genotype of CYP2C19m1 and CYP2C19m2 in control and esophageal cancer group has no significant difference. But attack rate of PM was 26.1% ,which was twifold higher than normal control （OR=2. 831,95%.CI： 1. 180--6. 793）. It had significant difference （P 〈20.05）. The frequency of GSTT1 gene deletion and normal genotype was 45.4%, 54. 8% in control group,and 64.8%, 35.2% in esophageal cancer group, respectively. The difference was significant. Conclusions I -phase metabolic enzyme CYP2C19 has genetic polymorphism in Kazakh. CYP2C19m1 and CYP2C19m2, two separated mutable allele gene, poor metabolizer of CYP2C19 participated the deactivation of carcinogens. Its low activation increases the susceptibility of Kazakh＇s esophageal cancer. GSTT1 （--） deletion genotype of Ⅱ -phase metabolic enzyme may be the important biomarker for Kazakh＇s esophageal cancer patients. It has important theoretics evidence and foundation to screen the CYP2C19,GSTT1 and establish the data bank of genetic polymorphism of the enzyme for prevention and early diagnosis in high risk Kazakh.