食管鳞癌中角蛋白14及胃泌素基因启动子区甲基化及蛋白表达特征研究

Study on the methylation and the expression of cytokeratin and gastrin gene in esophageal squamous cell carcinoma

目的通过检测角蛋白14(cytokeratin,CK)及胃泌素(Gastrin,GAS)基因在食管癌癌组织和癌旁正常组织中的表达和基因启动子甲基化分子改变,了解其在食管癌癌变过程中的变化特征和规律,阐明其在食管癌变机制中的作用。方法应用甲基化特异性PCR(methylation-specific polymerase chain reaction,MSP)对32例食管癌患者CK14及Gas基因启动子区甲基化状态进行检测;通过免疫组织化学染色SABC法对食管癌CK14及GAS蛋白表达情况进行检测。结果32例食管癌组织中有7例检测出CK14基因启动子区异常甲基化,甲基化阳性率为22%(7/32)。32例食管癌组织中有5例检测出Gas基因启动子区异常甲基化,甲基化阳性率为16%(5/32)。32例食管癌中细胞角蛋白表达强阳性为19例(59.3%),癌旁食管上皮组织4例(12.5%)CK14表达。32例食管癌中胃泌素表达强阳性为Gas 23例(71.8%),癌旁食管上皮组织3例(9.3%)Gas表达。结论 CK14及Gas蛋白的异常表达可能是食管癌变机制之一;CK14及Gas基因启动子低甲基化可能导致蛋白的高表达可能是食管癌癌变的发病机制之一。

Objective： To investigate the methylation status of the cytokeratin and gastrin gene in patients with esophageal squamous cell carcinoma by detecting the methylation and the gene expression of the cytokeratin gastrin in esophageal cancer tissue and adjacent normal tissues. Methods： Methylation specific PCR was adopted to detect the promoter methylation status of Gas gene promoter in 32 patients with esophageal squamous cell carcinoma. Immunohistochemical staining SABC method was adopted to detect the expression of GAS. Results： The methylation status of CK14 gene methylation was detected in 7 of the 32 cases of esophageal carcinoma. The positive rate of methylation was 22% （7/32） . The methylation status of methylation was detected in 5 of 32 cases of esophageal cancer. The positive rate of methylation was 16% （5/32） . There were 19 cases （59.3%） positive expression of cytokeratin in 32 cases of esophageal carcinoma and 4 cases （12.5%） of paracancerous esophageal epithelium. The positive expression of gastrin in esophageal carcinoma was 23 cases （71.8%） , 3 cases （9.3%） in adjacent esophageal epithelium. Conclusion： The methylation and the expression of Gas genes were the genetic change of esophageal squamous cell carcinoma.