title: Distinct p53 transcriptional programs dictate acute DNA-damage responses and tumor suppression.
abstract: The molecular basis for p53-mediated tumor suppression remains unclear. Here, to elucidate mechanisms of p53 tumor suppression, we use knockin mice expressing an allelic series of p53 transcriptional activation mutants. Microarray analysis reveals that one mutant, p53(25,26), is severely compromised for transactivation of most p53 target genes, and, moreover, p53(25,26) cannot induce G(1)-arrest or apoptosis in response to acute DNA damage. Surprisingly, p53(25,26) retains robust activity in senescence and tumor suppression, indicating that efficient transactivation of the majority of known p53 targets is dispensable for these pathways. In contrast, the transactivation-dead p53(25,26,53,54) mutant cannot induce senescence or inhibit tumorigenesis, like p53 nullizygosity. Thus, p53 transactivation is essential for tumor suppression but, intriguingly, in association with a small set of novel p53 target genes. Together, our studies distinguish the p53 transcriptional programs involved in acute DNA-damage responses and tumor suppression-a critical goal for designing therapeutics that block p53-dependent side effects of chemotherapy without compromising p53 tumor suppression.
authors.affiliation: Division of Radiation and Cancer Biology, Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA.
authors.forename: Colleen A
authors.initials: CA
authors.lastname: Brady
authors.forename: Dadi
authors.initials: D
authors.lastname: Jiang
authors.forename: Stephano S
authors.initials: SS
authors.lastname: Mello
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Johnson
authors.forename: Lesley A
authors.initials: LA
authors.lastname: Jarvis
authors.forename: Margaret M
authors.initials: MM
authors.lastname: Kozak
authors.forename: Daniela
authors.initials: D
authors.lastname: Kenzelmann Broz
authors.forename: Shashwati
authors.initials: S
authors.lastname: Basak
authors.forename: Eunice J
authors.initials: EJ
authors.lastname: Park
authors.forename: Margaret E
authors.initials: ME
authors.lastname: McLaughlin
authors.forename: Anthony N
authors.initials: AN
authors.lastname: Karnezis
authors.forename: Laura D
authors.initials: LD
authors.lastname: Attardi
mesh_terms: D000818:Animals; D017209:Apoptosis; D002453:Cell Cycle; D016922:Cellular Senescence; D004249:DNA Damage; D004260:DNA Repair; D055879:Gene Knock-In Techniques; D006801:Humans; D051379:Mice; D009154:Mutation; D009369:Neoplasms / Q000378:metabolism; D017434:Protein Structure, Tertiary; D015533:Transcriptional Activation; D016159:Tumor Suppressor Protein p53 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D016159:Tumor Suppressor Protein p53