THE ROLE OF METHYLATION IN THE PHENOTYPE-DEPENDENT MODULATION OF EPSTEIN-BARR NUCLEAR ANTIGEN-2 AND LATENT MEMBRANE-PROTEIN GENES IN CELLS LATENTLY INFECTED WITH EPSTEIN-BARR VIRUS
THE ROLE OF METHYLATION IN THE PHENOTYPE-DEPENDENT MODULATION OF EPSTEIN-BARR NUCLEAR ANTIGEN-2 AND LATENT MEMBRANE-PROTEIN GENES IN CELLS LATENTLY INFECTED WITH EPSTEIN-BARR VIRUS
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DOI：
10.1099/0022-1317-70-11-2989
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发表时间：
1989-11-01
影响因子：
3.8
通讯作者：
KLEIN, G
中科院分区：
文献类型：
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作者：
ERNBERG, I;FALK, K;KLEIN, G
在EB病毒（EBV）转化的类淋巴母细胞（LCL）细胞系中有规律地表达七种病毒编码的蛋白：EBV核抗原EBNA 1至6和潜伏膜蛋白（LMP）。在鼻咽癌（NPC）中，只有EBNA 1定期表达;在约50%的肿瘤中检测到LMP。在伯基特淋巴瘤（BL）肿瘤中，仅EBNA 1表达。而且，在保持体内肿瘤的表型标志物特征的BL衍生的细胞系（组I）中，仅表达EBNA 1。通过诱导或共培养从一个具有限制性I组模式的BL细胞系和一个NPC肿瘤中拯救EBV进入正常B细胞。在所得的LCL中，表达EBNA 1至6和LMP。我们使用甲基化敏感酶SmaI和HpaII通过限制性片段分析评估编码EBNA 2和LMP的基因的甲基化水平。这些基因广泛甲基化的第一组BL线雷尔和裸鼠传代C15鼻咽癌肿瘤，但在衍生的LCL去甲基化。在表达NPC肿瘤的LMP中，但在衍生的LCL中去甲基化。在表达LMP的编码外显子中甲基化。EBNA 1编码外显子在Rael系和NPC中甲基化，尽管表达。相比之下，oriP中的CpG对最初是低甲基化的，并且在它们转移到LCL后仍然如此。EBV基因甲基化的细胞表型依赖模式与EBNA和LMP表达的表型依赖模式相关。定位于控制区域（oriP和5′侧翼序列）的甲基化的特定模式也表明甲基化在EBNA和LMP表达的调节中的特定作用。
Seven virus-encoded proteins are regularly expressed in Epstein-Barr virus (EBV)-transformed lymphoblastoid (LCL) cell lines: the EBV nuclear antigens EBNA 1 to 6 and the latent membrane protein (LMP). In nasopharyngeal carcinoma (NPC), only EBNA 1 is regularly expressed; LMP is detected in about 50% of the tumours. In Burkitt's lymphoma (BL) tumours, only EBNA 1 is expressed. Also, in BL-derived cell lines that maintain the phenotypic markers characteristic of thein vivotumour (group I), only EBNA 1 is expressed. EBV was rescued by induction or cocultivation from one BL cell line with a restricted group I pattern, and from one NPC tumour, into normal B cells. In the resulting LCLs EBNA 1 to 6 and LMP were expressed. We assessed the level of methylation in the genes encoding EBNA 2 and LMP by restriction fragment analysis using the methylation-sensitive enzymesSmaI andHpaII. These genes were extensively methylated in the group I BL line Rael and the nude mouse-passaged C15 NPC tumour, but were demethylated in the derived LCLs. In the LMP expressing the NPC tumour, but were demethylated in the derived LCLs. In the LMP-expressing coding exons were methylated. The EBNA 1 coding exon was methylated in the Rael line and in NPC, in spite of expression. In contrast, CpG pairs inoriP were originally hypomethylated and remained so after their transfer to LCLs. The cell phenotype-dependent pattern of EBV gene methylation correlated with the phenotype-dependent pattern of EBNA and LMP expression. The specific patterns of methylation localized to controlling regions (oriP and 5′ flanking sequences) also suggest a specific role for methylation in the regulation of EBNA and LMP expression.