title: p53 Modulates Notch Signaling in MCF-7 Breast Cancer Cells by Associating With the Notch Transcriptional Complex Via MAML1.
abstract: p53 and Notch-1 play important roles in breast cancer biology. Notch-1 inhibits p53 activity in cervical and breast cancer cells. Conversely, p53 inhibits Notch activity in T-cells but stimulates it in human keratinocytes. Notch co-activator MAML1 binds p53 and functions as a p53 co-activator. We studied the regulation of Notch signaling by p53 in MCF-7 cells and normal human mammary epithelial cells (HMEC). Results show that overexpression of p53 or activation of endogenous p53 with Nutlin-3 inhibits Notch-dependent transcriptional activity and Notch target expression in a dose-dependent manner. This effect could be partially rescued by transfection of MAML1 but not p300. Standard and quantitative co-immunoprecipitation experiments readily detected a complex containing p53 and Notch-1 in MCF-7 cells. Formation of this complex was inhibited by dominant negative MAML1 (DN-MAML1) and stimulated by wild-type MAML1. Standard and quantitative far-Western experiments showed a complex including p53, Notch-1, and MAML1. Chromatin immunoprecipitation (ChIP) experiments showed that p53 can associate with Notch-dependent HEY1 promoter and this association is inhibited by DN-MAML1 and stimulated by wild-type MAML1. Our data support a model in which p53 associates with the Notch transcriptional complex (NTC) in a MAML1-dependent fashion, most likely through a p53-MAML1 interaction. In our cellular models, the effect of this association is to inhibit Notch-dependent transcription. Our data suggest that p53-null breast cancers may lack this Notch-modulatory mechanism, and that therapeutic strategies that activate wild-type p53 can indirectly cause inhibition of Notch transcriptional activity.
authors.affiliation: Korea Research Institute of Bioscience and Biotechnology (KRIBB), Ochang, Chungbuk, Republic of Korea.|Cardinal Bernardin Cancer Center, Loyola University Chicago, Chicago, Illinois.
authors.forename: Jieun
authors.initials: J
authors.lastname: Yun
authors.affiliation: Department of Biochemistry, University of Mississippi, Jackson, Mississippi.|Cancer Institute, University of Mississippi, Jackson, Mississippi.
authors.forename: Ingrid
authors.initials: I
authors.lastname: Espinoza
authors.affiliation: Stanley Scott Cancer Center, Louisiana State Health Sciences Center and Louisiana Cancer Research Consortium, New Orleans, Louisiana.
authors.forename: Antonio
authors.initials: A
authors.lastname: Pannuti
authors.affiliation: Department of Biochemistry, University of Mississippi, Jackson, Mississippi.|Cancer Institute, University of Mississippi, Jackson, Mississippi.
authors.forename: Damian
authors.initials: D
authors.lastname: Romero
authors.affiliation: Department of Biochemistry, University of Mississippi, Jackson, Mississippi.|Cancer Institute, University of Mississippi, Jackson, Mississippi.
authors.forename: Luis
authors.initials: L
authors.lastname: Martinez
authors.affiliation: Cancer Institute, University of Mississippi, Jackson, Mississippi.
authors.forename: Mary
authors.initials: M
authors.lastname: Caskey
authors.affiliation: Biopharmaceutical Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois.
authors.forename: Adina
authors.initials: A
authors.lastname: Stanculescu
authors.affiliation: Cardinal Bernardin Cancer Center, Loyola University Chicago, Chicago, Illinois.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Bocchetta
authors.affiliation: Department of Morphology, Surgery and Experimental Medicine, University of Ferrara, Ferrara, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Rizzo
authors.affiliation: Eppley Cancer Center, University of Nebraska, Omaha, Nebraska.
authors.forename: Vimla
authors.initials: V
authors.lastname: Band
authors.affiliation: Eppley Cancer Center, University of Nebraska, Omaha, Nebraska.
authors.forename: Hamid
authors.initials: H
authors.lastname: Band
authors.affiliation: College of Pharmacy, Gachon University, Incheon, Republic of Korea.
authors.forename: Hwan Mook
authors.initials: HM
authors.lastname: Kim
authors.affiliation: College of Pharmacy, Korea University, Sejong, Republic of Korea.
authors.forename: Song-Kyu
authors.initials: SK
authors.lastname: Park
authors.affiliation: College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, Republic of Korea.
authors.forename: Keon Wook
authors.initials: KW
authors.lastname: Kang
authors.affiliation: Department of Pharmacology, Georgetown University, Washington D.C.
authors.forename: Maria Laura
authors.initials: ML
authors.lastname: Avantaggiati
authors.affiliation: Department of Pathology, University of Mississippi, Jackson, Mississippi.
authors.forename: Christian R
authors.initials: CR
authors.lastname: Gomez
authors.affiliation: Department of Neuroscience, University of Florida, Gainesville, Florida.
authors.forename: Todd
authors.initials: T
authors.lastname: Golde
authors.affiliation: Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, Massachusetts.
authors.forename: Barbara
authors.initials: B
authors.lastname: Osborne
authors.affiliation: Stanley Scott Cancer Center, Louisiana State Health Sciences Center and Louisiana Cancer Research Consortium, New Orleans, Louisiana.
authors.forename: Lucio
authors.initials: L
authors.lastname: Miele
mesh_terms: D001665:Binding Sites; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D002135:Calcium-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism; D061986:MCF-7 Cells; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D046912:Multiprotein Complexes / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D034622:RNA Interference; D051881:Receptor, Notch1 / Q000235:genetics / Q000378:metabolism*; D000072099:Serrate-Jagged Proteins; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic; D014162:Transfection; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism*
chemical_list: D002135:Calcium-Binding Proteins; D004268:DNA-Binding Proteins; D036341:Intercellular Signaling Peptides and Proteins; C430872:MAML1 protein, human; D008565:Membrane Proteins; D046912:Multiprotein Complexes; C497761:NOTCH1 protein, human; D051881:Receptor, Notch1; D000072099:Serrate-Jagged Proteins; C495901:TP53 protein, human; D014157:Transcription Factors; D016159:Tumor Suppressor Protein p53