【作者】 何巧玉；

【导师】 陈香宇；

【作者基本信息】 郑州大学 ， 内科学， 2012， 硕士

【摘要】 背景食管癌是世界上最常见8大的恶性肿瘤之一,近20年来其发病率在全球范围内呈上升趋势,每年约380,000患者死于该病。但是,食管癌的发病机制至今仍不清楚。最近研究表明,基因启动子区的异常甲基化导致基因表达沉默,可能参与人类肿瘤的发病过程。染色质解旋酶DNA结合蛋白5(chromodomain helicase DNA-binding protein5)基因是chromodomain超家族的一员,是2003年新发现的抑癌基因。CHD5基因启动子区异常甲基化导致该基因沉默在不同的人类肿瘤中已有报道,但其在食管癌发生中的表观遗传学变化及调控机制尚不清楚。目的：研究食管鳞癌组织和食管癌细胞系KYSE70、KYSE140、SKGT4和YES2中CHD5基因表观遗传学改变,探讨CHD5基因甲基化作为食管癌诊断标志物的可行性。方法：用甲基化特异性聚合酶链反应(methylation specific PCR,MSP)检测72例食管鳞癌组织及成对癌旁组织,9例正常食管粘膜组织及4株食管癌细胞系中CHD5基因的甲基化状态,并用逆转录聚合酶链式反应(reverse transcriptionPCR,RT-PCR)检测CHD5基因在上述食管癌细胞系的表达。本实验采用SPSS17.0统计软件包进行统计分析,以a=0.05为显著检验水准。结果：69%(50/72)食管鳞癌组织发生CHD5基因启动子区甲基化,32%(23/72)癌旁组织发生甲基化,差异具有统计学意义(x2=20.254,P<0.05)。9例食管正常组织未发生甲基化,2株食管癌细胞系KYSE70、SKGT4中由于基因启动子区甲基化导致CHD5基因表达缺失,经5-aza-dc处理96h后CHD5重新表达。结论：CHD5基因在食管鳞癌中频繁发生甲基化；CHD5基因mRNA在食管癌细胞系中受甲基化调控,表观遗传学改变是其基因表达及转录的重要调节机制。更多还原

【Abstract】 Background:Esophageal cancer ranks as the8th most common cancer worldwide. The incidence of esophageal cancer increased rapidly in the past twenty years and about380,000cases died each year. However, the mechanisms contributing to carcinogenesis of esophageal cancer are still poorly understood. Recent studies showed that aberrant promoter DNA methylation contributes to gene silencing, may participate in the carcinogenesis of human cancer.Chromodomain helicase DNA-binding protein5(CHD5) is a member of chromodomain. It was been discovered as a novel tumor suppressor gene in2003. Promoter region methylation is related to loss of CHD5expression has been found in many human cancer. However, CHD5epigenetic changes in esophageal cancer remains unclear.Objective:To explore epigenetic changes of CHD5during esophageal squamous cell carcinoma and the possibility of CHD5promoter region methylation as human esophageal cancer marker. Method:Methylation-specific polymerase chain reaction (MSP) was used to detect the methylation status of CHD5in72cases esophageal squamous cell carcinoma and matched adjacent tissue, nine cases normal mucosa, and four esophageal cancer cell linesKYSE70, KYSE140, SKGT4and YES2. Reverse transcription polymerase chain reaction (RT-PCR) was performed to detect the expression of CHD5in esophageal cancer cell lines mentioned above. In this topic we use SPSS17.0statistical software package for statistical analysis, and the significant test standard was a=0.05.Results:69%(50/72) cases of esophageal squamous cell carcinoma were methylated, and32%(23/72)cases were methylated in matched adjacent tissue(x2=20.254, P<0.05). Nine cases of normal esophageal mucosa were unmethylated. Loss of CHD5expression was found in2esophageal cancer cell lines KYSE70and SKGT4with promoter region methylation, and after treatment with5-aza-dc for96h, the CHD5was re-expression.Conclusion:CHD5is frequently methylated in esophageal squamous cell carcinoma; The mRNA of CHD5is regulated by DNA methylatuion in esophageal cancer, epigenetic change may be an important regulation mechanism of its expression and transcription.更多还原