title: Targeting the MDM2/MDM4 interaction interface as a promising approach for p53 reactivation therapy.
abstract: Restoration of wild-type p53 tumor suppressor function has emerged as an attractive anticancer strategy. Therapeutics targeting the two p53-negative regulators, MDM2 and MDM4, have been developed, but most agents selectively target the ability of only one of these molecules to interact with p53, leaving the other free to operate. Therefore, we developed a method that targets the activity of MDM2 and MDM4 simultaneously based on recent studies indicating that formation of MDM2/MDM4 heterodimer complexes are required for efficient inactivation of p53 function. Using computational and mutagenesis analyses of the heterodimer binding interface, we identified a peptide that mimics the MDM4 C-terminus, competes with endogenous MDM4 for MDM2 binding, and activates p53 function. This peptide induces p53-dependent apoptosis in vitro and reduces tumor growth in vivo. Interestingly, interfering with the MDM2/MDM4 heterodimer specifically activates a p53-dependent oxidative stress response. Consistently, distinct subcellular pools of MDM2/MDM4 complexes were differentially sensitive to the peptide; nuclear MDM2/MDM4 complexes were particularly highly susceptible to the peptide-displacement activity. Taken together, these data identify the MDM2/MDM4 interaction interface as a valuable molecular target for therapeutic reactivation of p53 oncosuppressive function.
authors.affiliation: Institute of Cell Biology and Neurobiology, CNR, Roma, Italy.
authors.forename: Marsha
authors.initials: M
authors.lastname: Pellegrino
authors.affiliation: Institute of Cell Biology and Neurobiology, CNR, Roma, Italy. Institute of Medical Pathology, Catholic University of Roma, Roma, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Mancini
authors.affiliation: Institute of Cell Biology and Neurobiology, CNR, Roma, Italy.
authors.forename: Rossella
authors.initials: R
authors.lastname: Lucà
authors.affiliation: Department of Pharmaceutical Sciences, University of Perugia, Perugia, Italy.
authors.forename: Alice
authors.initials: A
authors.lastname: Coletti
authors.affiliation: Department of Pharmaceutical Sciences, University of Perugia, Perugia, Italy.
authors.forename: Nicola
authors.initials: N
authors.lastname: Giacchè
authors.affiliation: Regina Elena Cancer Institute, Roma, Italy.
authors.forename: Isabella
authors.initials: I
authors.lastname: Manni
authors.affiliation: European Brain Research Institute (EBRI) Rita Levi-Montalcini, Roma, Italy.
authors.forename: Ivan
authors.initials: I
authors.lastname: Arisi
authors.affiliation: European Brain Research Institute (EBRI) Rita Levi-Montalcini, Roma, Italy.
authors.forename: Fulvio
authors.initials: F
authors.lastname: Florenzano
authors.affiliation: Institute of Cell Biology and Neurobiology, CNR, Roma, Italy. Institute of Medical Pathology, Catholic University of Roma, Roma, Italy.
authors.forename: Emanuela
authors.initials: E
authors.lastname: Teveroni
authors.affiliation: Institute of Cell Biology and Neurobiology, CNR, Roma, Italy.
authors.forename: Marianna
authors.initials: M
authors.lastname: Buttarelli
authors.affiliation: Institute of Cell Biology and Neurobiology, CNR, Roma, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Fici
authors.affiliation: European Brain Research Institute (EBRI) Rita Levi-Montalcini, Roma, Italy.
authors.forename: Rossella
authors.initials: R
authors.lastname: Brandi
authors.affiliation: Regina Elena Cancer Institute, Roma, Italy.
authors.forename: Tiziana
authors.initials: T
authors.lastname: Bruno
authors.affiliation: Regina Elena Cancer Institute, Roma, Italy.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Fanciulli
authors.affiliation: European Brain Research Institute (EBRI) Rita Levi-Montalcini, Roma, Italy.
authors.forename: Mara
authors.initials: M
authors.lastname: D'Onofrio
authors.affiliation: Regina Elena Cancer Institute, Roma, Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: Piaggio
authors.affiliation: Department of Pharmaceutical Sciences, University of Perugia, Perugia, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Pellicciari
authors.affiliation: Institute of Medical Pathology, Catholic University of Roma, Roma, Italy.
authors.forename: Alfredo
authors.initials: A
authors.lastname: Pontecorvi
authors.affiliation: Center for Human Genetics, KU-Leuven, Leuven, Belgium. Center for the Biology of Disease, VIB, Leuven, Belgium.
authors.forename: Jean Christophe
authors.initials: JC
authors.lastname: Marine
authors.affiliation: Department of Pharmaceutical Sciences, University of Perugia, Perugia, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Macchiarulo
authors.affiliation: Institute of Cell Biology and Neurobiology, CNR, Roma, Italy. fabiola.moretti@cnr.it.
authors.forename: Fabiola
authors.initials: F
authors.lastname: Moretti
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology; D018797:Cell Cycle Proteins; D045744:Cell Line, Tumor; D045325:HCT116 Cells; D006801:Humans; D061986:MCF-7 Cells; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D008819:Mice, Nude; D058990:Molecular Targeted Therapy; D009369:Neoplasms / Q000188:drug therapy*; D009687:Nuclear Proteins / Q000378:metabolism*; D018384:Oxidative Stress / Q000502:physiology; D010455:Peptides / Q000627:therapeutic use*; D011485:Protein Binding / Q000502:physiology; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D051736:Proto-Oncogene Proteins c-mdm2 / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*; D054875:Ubiquitination
chemical_list: D018797:Cell Cycle Proteins; C482775:MDM4 protein, human; D009687:Nuclear Proteins; D010455:Peptides; D011518:Proto-Oncogene Proteins; D017382:Reactive Oxygen Species; D016159:Tumor Suppressor Protein p53; C497206:MDM2 protein, human; D051736:Proto-Oncogene Proteins c-mdm2