Shen Jing, Wang Runtian, Wang Liwei, Wang Zhaoxi, Xing Houxun, Wang Binyan, Li Maosen, Hua Zhaolai, Wang Jianming, Guo Chunhua, Wang Xinru, Xu Xiping
Department of Epidemiology & Biostatistics, School of Public Health, Nanjing Medical University, Nanjing 210029, China.
Zhonghua Liu Xing Bing Xue Za Zhi. 2002 Oct;23(5):374-7.
To study the relationship between polymorphism of inducible Nitric Oxide Synthase (iNOS) gene and the susceptibility of intestinal type stomach cancer and stomach cardia cancer in Chinese people.
A community-based case-control study was designed. Ninety-three intestinal type of stomach cancer and 50 stomach cardia cancer patients with endoscopy and pathology diagnosis were identified as cases. Two hundred and forty-six controls served as controls.
C-->T polymorphism was found in exon 16 of iNOS gene, which changed the coding amino acid from serine to leucine, and formed a recognition site identified by Tsp 509 I restriction enzyme (we called it C-->T polymorphism). The T allele gene frequency in the control group was 13.21%. No statistically significant difference was found between C-->T polymorphism alone and the increased susceptibility to intestinal stomach cancer or stomach cardia cancer. A significant type 2 multiplicative interaction was found in increasing both the risk of intestinal stomach cancer and stomach cardia cancer when both C-->T polymorphism and tobacco smoking exposure existed. An additive interaction model, which showed statistically significant difference, was found to increase only the risk of stomach cardia cancer when CagA antibody shared negative but C-->T polymorphism occurred.
C-->T polymorphism of iNOS gene was considered as one of the possible susceptible genes, which specifically increased the risk of tobacco-related but CagA negative types of intestinal stomach cancer and stomach cardia cancer.
研究诱导型一氧化氮合酶（iNOS）基因多态性与中国人肠型胃癌和贲门癌易感性之间的关系。
设计一项基于社区的病例对照研究。93例经内镜和病理诊断的肠型胃癌患者和50例贲门癌患者被确定为病例。246名对照者作为对照组。
在iNOS基因第16外显子中发现C→T多态性，该多态性使编码氨基酸由丝氨酸变为亮氨酸，并形成了一个可被Tsp 509 I限制性内切酶识别的位点（我们称之为C→T多态性）。对照组中T等位基因频率为13.21%。单独的C→T多态性与肠型胃癌或贲门癌易感性增加之间未发现统计学显著差异。当同时存在C→T多态性和吸烟暴露时，在增加肠型胃癌和贲门癌风险方面发现显著的2型相乘交互作用。当CagA抗体呈阴性但发生C→T多态性时，发现一种显示出统计学显著差异的相加交互作用模型，仅增加贲门癌风险。
iNOS基因的C→T多态性被认为是可能的易感基因之一，它特异性增加了与烟草相关但CagA阴性类型的肠型胃癌和贲门癌的风险。
