Identification and investigation of methylated genes in hepatoma
Identification and investigation of methylated genes in hepatoma
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DOI：
10.1016/j.ejca.2005.02.014
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发表时间：
2005-05-01
影响因子：
8.4
通讯作者：
Saisho, H
中科院分区：
文献类型：
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作者：
Chiba, T;Yokosuka, O;Saisho, H
DNA甲基化异常导致的基因沉默在肿瘤的发生中起着重要作用。以往的基因芯片分析表明，肝细胞生长因子激活物抑制物2/胎盘bikunin(HAI2/PB)基因等14个基因在5-aza-2‘脱氧胞苷(5aza-DC)处理后，在多个肝癌细胞系中表现出特别高的诱导性。在本研究中，我们研究了除HAI2/PB基因外的所有这些基因，并分别用亚硫酸氢盐基因组测序和染色质免疫沉淀(ChIP)法检测了DNA甲基化状态和乙酰化组蛋白水平。用甲基化特异性聚合酶链式反应(MSP)检测原发性肝癌组织中的异常甲基化。E-钙粘蛋白、胶原1α2(COL1A2)、胰岛素样生长因子结合蛋白2(IGFBP2)、结缔组织生长因子(CTGF)和纤维连接蛋白1等基因在多个肝癌细胞系中出现异常甲基化。芯片检测显示，除纤维连接蛋白1外，组蛋白的DNA甲基化和脱乙酰基普遍共存。在对24例原发性肝癌组织的进一步研究中，分别在13例、18例、4例和10例原发性肝癌组织中检测到COL1A2、IGFBP2、CTGF和纤维连接蛋白1的甲基化信号。总之，在肝癌细胞系中检测到COL1A2、IGFBP2、CTGF和FN-1基因的异常甲基化。我们还发现，除了纤维连接蛋白1外，5‘CpG岛的甲基化和组蛋白去乙酰化在基因表达调控中普遍并存。MSP在肝癌组织中的结果表明，其中一些基因可能参与了肝癌的发生发展。(C)2005爱思唯尔有限公司。保留所有权利。
Gene silencing due to aberrant DNA methylation plays an important role in carcinogenesis. Previous microarray analysis demonstrated that 14 genes, including hepatocyte growth factor activator inhibitor 2/placental bikunin (HAI2/PB) gene, showed particularly high inductions after 5-aza-2'deoxycytidine (5Aza-dC) treatment in multiple hepatoma cell lines. In the present study, we studied all of these genes except for the HAI2/PB gene and examined DNA methylation status and levels of acetylated histones using bisulphite genomic sequencing and the chromatin immunoprecipitation (ChIP) assay, respectively. Aberrant methylation in primary hepatoma tissues was also examined using methylation-specific polymerase chain reaction (MSP). Genes for E-cadherin, collagen type 1 alpha 2 (COL1A2), insulin-like growth factor binding protein 2 (IGFBP2), connective tissue growth factor (CTGF) and fibronectin 1 exhibited aberrant methylation in several hepatoma cell lines. The ChIP assay showed that DNA methylation and deacetylation of histones generally coexist except for fibronectin 1. In further studies of 24 primary hepatoma tissues, methylation signals for COL1A2, IGFBP2, CTGF and fibronectin 1 were detected in 13, 18, 4 and 10 patients, respectively. In conclusion, aberrant methylation of COL1A2, IGFBP2, CTGF and fibronectin 1 genes were detected in hepatoma cell lines. We also demonstrated that the methylation of 5'CpG islands and histone deacetylation generally coexisted in the regulation of gene expression except for fibronectin 1. The results of MSP in hepatoma tissues suggested that some of these genes might be involved in the development or progression of hepatoma. (c) 2005 Elsevier Ltd. All rights reserved.