摘要
目的检测遗传性胃癌家系患者的E-钙黏附素基因（CDHI）蛋白表达和启动子区甲基化及胚系和体细胞突变情况，探讨CDH1基因在中国遗传性胃癌中的作用。方法采用免疫组织化学、甲基化特异聚合酶链反应（MS—PCR）、变性高效液相色谱技术（DHPLC）和直接测序法对1994年6月至2007年10月胃癌数据库中筛选的8个符合遗传性胃癌筛选标准患者的肿瘤和正常组织标本的CDH1基因进行蛋白表达、启动子甲基化和体细胞和胚系突变的全基因筛查。结果8例先证者中，7例肿瘤标本CDH1基因蛋白表达阴性，1例表达明显下调；6例先证者肿瘤标本表现为启动子甲基化，5例先证者肿瘤标本中发现了6个突变，包括两个同义突变和4个错义突变，在正常组织未发现同样的种系突变；4例先证者表现为既有体细胞突变又有启动子甲基化；1例既没有体细胞突变也没有启动子甲基化；2例患者仅表现为启动子甲基化，1例仅发现体细胞突变。结论CDH1种系突变在我国遗传性胃癌中可能并不常见，CDH1基因的体细胞突变和启动子甲基化可能协同的导致遗传性胃癌患者CDH1基因下调。
Objective To investigate the protein expression, methylation promoter, somatic and germ-line mutations of E-cadherin gene （ CDH1 ） in hereditary gastric cancer in China and to investigate its possible roles. Methods Eight probands diagnozed with ICG-HGC criterion were enrolled in our database from June 1994 to October 2007. Tumor tissues were detected for CDH1 expression by using immunohistochemistry （IHC） methods. CDH1 DNA sequencing was performed for all its 16 exons both in tumor and normal tissues of the same patients to detect somatic and germ-line mutations. Methylation promoter study was performed by using specific primers and polymerase chain reaction （PCR） methods. Results IHC analysis confirmed that the CDH1 expression was negative in 7 probands and downregulated in the other on proband. Six mutations in five probands were found with DNA sequencing： two silent mutations and four missense mutations. All six mutations were absent in normal tissues, thereby excluded its presence in germ-line cells. Both DNA missense mutations and gene silencing through promoter methylation was found in 4 probands. Two probands has only promoter methylation and one proband had only silent mutation. No DNA missense mutations or promoter methylation was found in one proband. Conclusions CDH1 gene germ-line mutations are relatively rare in hereditary gastric cancer in China, and whereas CDH1 somatic mutations and promoter methylation synergistically induce CDH1 downregulation in these patients.
出处
《中华外科杂志》
CAS
CSCD
北大核心
2009年第16期1204-1208,共5页
Chinese Journal of Surgery
基金
国家自然科学基金资助项目（30571832）
广东省自然科学基金资助项目（7001669）
广东省科技计划资助项目（20088030301134）
