Role of DNA methylation for expression of novel stem cell marker CDCP1 in hematopoietic cells
Role of DNA methylation for expression of novel stem cell marker CDCP1 in hematopoietic cells
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DOI：
10.1038/sj.leu.2404312
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发表时间：
2006-09-01
期刊：
影响因子：
11.4
通讯作者：
Aozasa, K.
中科院分区：
文献类型：
--
作者：
Kimura, H.;Morii, E.;Aozasa, K.
CDCP1是一种新的干细胞标记物，在造血细胞系K562中表达，而在Jurkat中不表达。当CDCP1启动子外源转染Jurkat时，Jurkat的启动子活性与K562相当，这表明增强转录的因子存在，但干扰了Jurkat的功能。报告基因分析和si- rna介导的敲低实验表明，锌指蛋白zfp67能够增强CDCP1的转录。zfp67在Jurkat中的表达量与K562相当，但染色质免疫沉淀显示zfp67在K562中与CDCP1启动子结合，而在Jurkat中不与CDCP1启动子结合。CDCP1启动子周围存在CpG序列，在Jurkat中存在大量甲基化，而在K562中没有。在Jurkat中加入去甲基化试剂可诱导CDCP1表达，增加zfp67与CDCP1启动子的结合。在正常造血细胞如CD34（+）、CD38（-）细胞、淋巴细胞和粒细胞中，甲基化CpG序列比例与CDCP1表达水平呈负相关。淋巴细胞CpG序列重度甲基化，CpG序列去甲基化诱导CDCP1表达，并通过过表达zfp67进一步提高其表达水平。DNA的甲基化似乎通过控制染色质DNA和转录因子之间的相互作用来调节CDCP1的细胞特异性表达。
CDCP1, a novel stem cell marker, is expressed in hematopoietic cell line K562 but not in Jurkat. When CDCP1 promoter was transfected exogenously, Jurkat showed comparable promoter activity with K562, suggesting that the factor to enhance transcription was present but interfered to function in Jurkat. The reporter assay and si-RNA-mediated knockdown experiment revealed that zfp67, a zinc-finger protein, enhanced CDCP1 transcription. Amount of zfp67 in Jurkat was comparable with K562, but chromatin immunoprecipitation showed that zfp67 bound to CDCP1 promoter in K562 but not in Jurkat. There are CpG sequences around the promoter of CDCP1, which were heavily methylated in Jurkat but not in K562. Addition of demethylating reagent to Jurkat induced CDCP1 expression, and increased the zfp67 binding to CDCP1 promoter. Among normal hematopoietic cells such as CD34(+)CD38(-) cells, lymphocytes and granulocytes, inverse correlation between proportion of methylated CpG sequences and CDCP1 expression level was found. Demethylation of CpG sequences in lymphocytes, in which CpG sequences were heavily methylated, induced CDCP1 expression and its expression level further increased through zfp67 overexpression. The methylation of DNA appeared to regulate the cell-type-specific expression of CDCP1 through the control of interaction between chromatin DNA and transcription factors.