胃癌是发病率很高的恶性肿瘤之一。幽门螺杆菌感染与Mist1基因启动子区甲基化密切相关，而Mist1启动子区的甲基化及其下游基因表达沉默与胃癌的发生密切相关。本研究旨在阐明幽门螺杆菌感染诱导的Mist1基因启动子区甲基化以及其所导致下游基因沉默在胃癌致癌过程中的作用，以及其对胃癌侵袭转移的影响。并进一步以Mist1基因启动子区甲基化为依托，明确其在胃癌患者血标本中的表达情况，为胃癌的早期无创性筛查提供新的方法和理论依据，促进胃癌的早期治疗，改善胃癌患者的生存质量。

The incidence of gastric cancer is extremely high. The Helicobacter pylori infection may lead to the Mist1 promoter hypermethylation. The hypermethylation of Mist1 gene promoter and the silence of Mist1 expression is closely related to the incidence of gastric cancer. The purpose of this study is to clarify the Helicobacter pylori induced Mist1 promoter hypermethylation and the silence of Mist1 expression in gastric carcinogenesis and metastasis. Further, base on the methylation status of the Mist1 in blood samples, we may provide a new method of.noninvasive screening in detecting gastric cancer in order to improve the quality of life of the patients with gastric cancer.