ChIP-on-Chip Analysis of In Vivo Mutant p53 Binding To Selected Gene Promoters
ChIP-on-Chip Analysis of In Vivo Mutant p53 Binding To Selected Gene Promoters
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DOI：
10.1089/omi.2010.0084
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发表时间：
2011-05-01
影响因子：
3.3
通讯作者：
Blandino, Giovanni
中科院分区：
文献类型：
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作者：
Dell'Orso, Stefania;Fontemaggi, Giulia;Blandino, Giovanni
越来越多的证据表明，突变的P53蛋白存在于许多人类肿瘤中，获得了致癌活性，可以积极地促进肿瘤的发生。突变型P53蛋白已被广泛证明可以影响多个涉及癌症生物学各个方面的基因的表达。我们在这里展示了突变型p53与一组154个启动子结合的芯片上分析，这些启动子由验证的和推测的突变型p53靶基因组成。通过使用突变型p53R175H免疫沉淀获得的染色质在增殖的SKBr3乳腺癌细胞中，我们发现突变型p53与154个启动子中的40个结合。SiRNA介导的突变型p53下调调控其中一些靶基因的转录丰度。三分之二的突变的p53结合启动子也被p300或PCAF乙酰基转移酶激活，这强烈表明存在转录活性复合体。我们还发现，在突变型P53结合的启动子中，核转录因子-kB结合位点过表达；芯片分析证实，在突变型P53结合的启动子中，有27个与核因子-kB p65结合，表明突变型p53可以影响这些核因子-kB靶基因的转录输出。
Growing evidence shows that mutant p53 proteins, which are present in many human tumors, gain oncogenic activities that can actively contribute to tumorigenesis. Mutant p53 proteins have been extensively shown to affect the expression of several genes involved in various aspects of cancer biology. We show here the ChIP-on-chip analysis of mutant p53 binding to a set of 154 promoters, composed of both validated and putative mutant p53 target genes. By using the chromatin obtained from mutant p53R175H-immunoprecipitation in proliferating SKBr3 breast cancer cells, we found that mutant p53 binds to 40 of the 154 promoters analyzed. siRNA-mediated mutant p53 knock-down modulates the transcript abundance of some of these target genes. Two-thirds of the mutant p53-bound promoters were also engaged by either p300 or PCAF acetyl-transferases, strongly indicating the presence of transcriptionally active complexes. We also found that NF-kB binding sites are overrepresented among the mutant p53-bound promoters; a ChIP-on-chip analysis confirmed that NF-kB p65 binds to 27 of the mutant p53-bound promoters, indicating that mutant p53 could influence the transcriptional output of these NF-kB target genes.