High-resolution analysis of CpG methylation and in vivo protein-DNA interactions at the alternative Epstein-Barr virus latency promoters Qp and Cp in the nasopharyngeal carcinoma cell line C666-1
High-resolution analysis of CpG methylation and in vivo protein-DNA interactions at the alternative Epstein-Barr virus latency promoters Qp and Cp in the nasopharyngeal carcinoma cell line C666-1
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DOI：
10.1007/s11262-007-0095-y
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发表时间：
2007-10-01
期刊：
影响因子：
1.6
通讯作者：
Minarovits, Janos
中科院分区：
文献类型：
--
作者：
Bakos, Agnes;Banati, Ferenc;Minarovits, Janos
EB病毒（EBV）编码的核抗原（EBNA）的转录物起始于位于病毒基因组的BamHI W、C或Q片段中的备选启动子（对于EBNA 1-6转录物为Wp、Cp，而仅对于EBNA 1转录物为Qp）。为了了解宿主细胞依赖性表达的EBNA在EBV相关的肿瘤（淋巴瘤和癌）和体外转化的细胞系，有必要分析的调控机制，管理的替代启动子的EBNA转录的活性。这些研究主要集中在携带潜伏EBV基因组的淋巴细胞系上，因为缺乏在组织培养中培养期间保持潜伏EBV基因组的EBV相关癌细胞系。我们利用独特的鼻咽癌细胞系C666-1，窝藏EB病毒基因组，并进行了详细的分析CpG甲基化模式和体内蛋白质-DNA相互作用的潜伏启动子Qp和Cp。我们发现，活性的，未甲基化的Qp标记有细胞转录因子和病毒蛋白EBNA 1的强足迹。相反，我们不能检测到相关转录因子与甲基化的沉默Cp的结合。我们的结论是，在上皮来源的C666-1细胞中的Qp和Cp的表观遗传标记类似于I组伯基特淋巴瘤细胞系。
Transcripts for the Epstein-Barr virus (EBV) encoded nuclear antigens (EBNAs) are initiated at alternative promoters (Wp, Cp, for EBNA 1-6 transcripts and Qp, for EBNA 1 transcripts only) located in the BamHI W, C or Q fragment of the viral genome. To understand the host-cell dependent expression of EBNAs in EBV-associated tumors (lymphomas and carcinomas) and in vitro transformed cell lines, it is necessary to analyse the regulatory mechanisms governing the activity of the alternative promoters of EBNA transcripts. Such studies focused mainly on lymphoid cell lines carrying latent EBV genomes, due to the lack of EBV-associated carcinoma cell lines maintaining latent EBV genomes during cultivation in tissue culture. We took advantage of the unique nasopharyngeal carcinoma cell line, C666-1, harboring EBV genomes, and undertook a detailed analysis of CpG methylation patterns and in vivo protein-DNA interactions at the latency promoters Qp and Cp. We found that the active, unmethylated Qp was marked with strong footprints of cellular transcription factors and the viral protein EBNA 1. In contrast, we could not detect binding of relevant transcription factors to the methylated, silent Cp. We concluded that the epigenetic marks at Qp and Cp in C666-1 cells of epithelial origin resemble those of group I Burkitt's lymphoma cell lines.