Pi类谷胱苷肽转移酶基因多态性与胃黏膜肠上皮化生癌变风险

Polymorphism of glutathione S-transferase P1 and correlation there of with carcinogenesis risk of gastric intestinal metaplasia

目的了解Pi类谷胱苷肽转移酶基因1（GSTP1）多态性与肠化生之间的关系，进一步探讨不同类型肠化生的癌变风险。方法利用PCR-RFLP法检测87例正常组、87例肠化生组和87例胃癌组GSTP1不同等位基因的分布。利用HID-AB-pH2．5进行肠化生分类。结果与正常对照组相比，携带G等位基因者发生肠化生的风险增加到1．944倍（95％CI，1．177～3．209），罹患胃癌的风险性增加3．605倍（95％CI，2．217～5．863）。携带G等位基因发生Ⅱ型肠化生风险增加到2．747倍（95％CI，1．475～5．114），发生Ⅲ型肠化生的风险增加到3．451倍（95％CI，1．556～7．657）。与Ⅰ型肠化生相比，携带G等位基因肠化生发生Ⅱ、Ⅲ型肠化生和胃癌的风险性分别增加到2．905倍（95％CI，1．341～6．293），3．650倍（95％CI，1．455～9．153），3．813倍（95％CI，1．953～7．444）。结论携带G等位基因者发生肠化生和胃癌的风险性增加，更易发生Ⅱ、Ⅲ型肠化生；携带G等位基因的肠化生与胃癌有着相似的遗传特性，可作为胃癌高危个体进行定期随访。

Objective To investigate the distribution of polymorphism of glutathione S-transferase P1 （ GSTP1 ） in different kinds gastric intestinal metaplasia （ IM ）, and the carcinogenesis risk of different types of IM . Methods Peripheral blood samples were collected from 87 gastric cancer patients, 87 intestinal metaplasia patients, and 87 healthy persons as controls. Polymerase chain reaction （PCR） and restriction fragment length polymorphism （RFLP） were used to analyze the distribution of different alleles of GSTP1. Biopsy specimens of gastric mucous membrane were collected by gastroscopy. Histochemical staining for mucin was used to identify the kinds of IM. Results The G allele rates of the IM and gastric cancer groups were both significantly higher than that of the control group （ χ^2 = 6. 921, P = 0. 009 ; χ^2 = 28. 787, P =0. 000）. The risk of IM of those with G allele was 1. 944 times higher then that of the normal controls （95% （21： 1. 177 -3. 209） , and the risk of gastric cancer of those with G allele was 3. 605 times higher （95% （21：2. 217 -5. 863）. The G allele rate of the gastric cancer group was significantly higher than that of he IM group （χ^2 =7.687, P =0.006）. The G allele rates of the type Ⅱ and Ⅲ IM were significantly higher than that of the normal controls （ χ^2 = 9. 981, P = 0.001 ; χ^2 = 8. 845, P = 0.002）. The risk of type Ⅱ IM of the subjects with G allele was 2. 747 times higher than that of the normal controls （ 95% CI： 1. 475 - 5.114） , and the risk of type Ⅲ IM of the subjects with G allele was 3. 451 times higher （95% CI：1.556 -7. 657）. The risks of type Ⅱ IM, type Ⅲ IM, and gastric cancer of the subjects with allele G of GSTP1 gene were 2. 905, 3. 650, and 3. 813 times higher than those of the normal controls respectively （95% CI： 1.341 -6.293,1.455 -9. 153 and 1.953 -7.444 respectively）. Conclusion The individuals with G allele show an inereased risk of developing IM and gastric cancer, especially type Ⅱ and Ⅲ IM . IM patients with G allele have the genetic characteristics similar to those of gastric cancer, so they should be regarded as high-risk individuals of gastric cancer and followed up regularly.