title: ChIP-on-chip analysis of in vivo mutant p53 binding to selected gene promoters.
abstract: 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.
authors.affiliation: Translational Oncogenomics Unit, Regina Elena Cancer Institute, Rome, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: Dell'Orso
authors.forename: Giulia
authors.initials: G
authors.lastname: Fontemaggi
authors.forename: Perry
authors.initials: P
authors.lastname: Stambolsky
authors.forename: Frauke
authors.initials: F
authors.lastname: Goeman
authors.forename: Christine
authors.initials: C
authors.lastname: Voellenkle
authors.forename: Massimo
authors.initials: M
authors.lastname: Levrero
authors.forename: Sabrina
authors.initials: S
authors.lastname: Strano
authors.forename: Varda
authors.initials: V
authors.lastname: Rotter
authors.forename: Moshe
authors.initials: M
authors.lastname: Oren
authors.forename: Giovanni
authors.initials: G
authors.lastname: Blandino
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites / Q000235:genetics; D045744:Cell Line, Tumor; D002843:Chromatin / Q000378:metabolism; D047369:Chromatin Immunoprecipitation; D016384:Consensus Sequence / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D050505:Mutant Proteins / Q000235:genetics / Q000378:metabolism*; D016328:NF-kappa B / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D011401:Promoter Regions, Genetic; D011485:Protein Binding / Q000502:physiology; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic / Q000235:genetics; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism*; D050880:p300-CBP Transcription Factors / Q000378:metabolism; D000099224:p300-CBP-Associated Factor
chemical_list: D002843:Chromatin; D004268:DNA-Binding Proteins; D050505:Mutant Proteins; D016328:NF-kappa B; D014157:Transcription Factors; D016159:Tumor Suppressor Protein p53; D050880:p300-CBP Transcription Factors; D000099224:p300-CBP-Associated Factor