Identification of genes directly regulated by the oncogene ZNF217 using chromatin immunoprecipitation (ChIP)-chip assays
Identification of genes directly regulated by the oncogene ZNF217 using chromatin immunoprecipitation (ChIP)-chip assays
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DOI：
10.1074/jbc.m611752200
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发表时间：
2007-03-30
影响因子：
4.8
通讯作者：
Farnham, Peggy J.
中科院分区：
文献类型：
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作者：
Krig, Sheryl R.;Jin, Victor X.;Farnham, Peggy J.
有研究提出，在多种肿瘤中20q13位点扩增的ZNF217在肿瘤转化过程中起关键作用。ZNF217已在含有抑制蛋白（如CtBP2）的复合物中纯化，这表明它具有转录抑制蛋白的作用。然而，由于缺乏已知的靶基因，ZNF217的功能尚未得到很好的表征。使用全局染色质免疫沉淀（ChIP）芯片方法，我们在三种肿瘤细胞系（MCF7， SW480和intera2）中鉴定了数千个ZNF217结合位点。对Ntera2细胞中ZNF217的进一步分析表明，许多启动子与ZNF217和CtBP2结合，其中一部分启动子在去除ZNF217后被激活。因此，我们的体内研究证实了含ZNF217复合物的体外生化分析，并支持ZNF217作为转录抑制因子的假设。基因本体论分析显示，ZNF217在intera2细胞中的靶点参与器官发育，提示ZNF217的一个功能可能是抑制分化。因此，我们发现，与维甲酸一起分化的intera2细胞导致ZNF217的下调。我们对数千个ZNF217靶基因的鉴定将有助于进一步研究ZNF217在肿瘤转化过程中异常表达的后果。
It has been proposed that ZNF217, which is amplified at 20q13 in various tumors, plays a key role during neoplastic transformation. ZNF217 has been purified in complexes that contain repressor proteins such as CtBP2, suggesting that it acts as a transcriptional repressor. However, the function of ZNF217 has not been well characterized due to a lack of known target genes. Using a global chromatin immunoprecipitation (ChIP)-chip approach, we identified thousands of ZNF217 binding sites in three tumor cell lines (MCF7, SW480, and Ntera2). Further analysis of ZNF217 in Ntera2 cells showed that many promoters are bound by ZNF217 and CtBP2 and that a subset of these promoters are activated upon removal of ZNF217. Thus, our in vivo studies corroborate the in vitro biochemical analyses of ZNF217-containing complexes and support the hypothesis that ZNF217 functions as a transcriptional repressor. Gene ontology analysis showed that ZNF217 targets in Ntera2 cells are involved in organ development, suggesting that one function of ZNF217 may be to repress differentiation. Accordingly we show that differentiation of Ntera2 cells with retinoic acid led to down-regulation of ZNF217. Our identification of thousands of ZNF217 target genes will enable further studies of the consequences of aberrant expression of ZNF217 during neoplastic transformation.