title: Non-genotoxic activation of p53 through the RPL11-dependent ribosomal stress pathway.
abstract: Nucleolar disruption has recently emerged as a relevant means to activate p53 through inhibition of HDM2 by ribosome-free RPL11. Most drugs that induce nucleolar disruption also possess important genotoxic activity, which can have lasting mutagenic effects. Therefore, it is of interest to identify compounds that selectively produce nucleolar disruption in the absence of DNA damage. Here, we have performed a high-throughput screening to search for nucleolar disruptors. We have identified an acridine derivative (PubChem CID-765471) previously known for its capacity to activate p53 independently of DNA damage, although the molecular mechanism underlying p53 activation had remained uncharacterized. We report that CID-765471 produces nucleolar disruption by inhibiting ribosomal DNA transcription in a process that includes the selective degradation of the RPA194 subunit of RNA polymerase I. Following nucleolar disruption, CID-765471 activates p53 through the RPL11/HDM2 pathway in the absence of detectable DNA damage. In a secondary screening of compounds approved for medical use, we identify two additional acridine derivatives, aminacrine and ethacridine, that operate in a similar manner as CID-765471. These findings provide the basis for non-genotoxic chemotherapeutic approaches that selectively target the nucleolus.
authors.affiliation: Tumour Suppression Group, Experimental Therapeutics Program and Confocal Microscopy Unit, Spanish National Cancer Research Centre (CNIO), Madrid, E28029, Spain.
authors.forename: Lucia
authors.initials: L
authors.lastname: Morgado-Palacin
authors.affiliation: Tumour Suppression Group, Experimental Therapeutics Program and Confocal Microscopy Unit, Spanish National Cancer Research Centre (CNIO), Madrid, E28029, Spain.
authors.forename: Susana
authors.initials: S
authors.lastname: Llanos
authors.affiliation: Experimental Therapeutics Program and.
authors.forename: Manuel
authors.initials: M
authors.lastname: Urbano-Cuadrado
authors.affiliation: Experimental Therapeutics Program and.
authors.forename: Carmen
authors.initials: C
authors.lastname: Blanco-Aparicio
authors.affiliation: Confocal Microscopy Unit, Spanish National Cancer Research Centre (CNIO), Madrid, E28029, Spain.
authors.forename: Diego
authors.initials: D
authors.lastname: Megias
authors.affiliation: Experimental Therapeutics Program and.
authors.forename: Joaquín
authors.initials: J
authors.lastname: Pastor
authors.affiliation: Tumour Suppression Group, Experimental Therapeutics Program and Confocal Microscopy Unit, Spanish National Cancer Research Centre (CNIO), Madrid, E28029, Spain mserrano@cnio.es.
authors.forename: Manuel
authors.initials: M
authors.lastname: Serrano
mesh_terms: D000166:Acridines / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D015152:Blotting, Northern; D015153:Blotting, Western; D001859:Bone Neoplasms / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D003110:Colonic Neoplasms / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D004249:DNA Damage / Q000187:drug effects; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D057166:High-Throughput Screening Assays; D006801:Humans; D047468:Immunoprecipitation; D009287:Naphthyridines / Q000008:administration & dosage / Q000494:pharmacology*; D012516:Osteosarcoma / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D004364:Pharmaceutical Preparations / Q000008:administration & dosage / Q000378:metabolism*; D051736:Proto-Oncogene Proteins c-mdm2 / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012269:Ribosomal Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism*
chemical_list: D000166:Acridines; C000595196:CID-765471; D009287:Naphthyridines; D004364:Pharmaceutical Preparations; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D012269:Ribosomal Proteins; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53; C027624:ribosomal protein L11; C497206:MDM2 protein, human; D051736:Proto-Oncogene Proteins c-mdm2