Non-genotoxic activation of p53 through the RPL11-dependent ribosomal stress pathway

Lucia Morgado-Palacin; Susana Llanos; Manuel Urbano-Cuadrado; Carmen Blanco-Aparicio; Diego Megias; Joaquín Pastor; Manuel Serrano

doi:10.1093/carcin/bgu220

Non-genotoxic activation of p53 through the RPL11-dependent ribosomal stress pathway

Carcinogenesis. 2014 Dec;35(12):2822-30. doi: 10.1093/carcin/bgu220. Epub 2014 Oct 24.

Authors

Lucia Morgado-Palacin¹, Susana Llanos¹, Manuel Urbano-Cuadrado², Carmen Blanco-Aparicio², Diego Megias³, Joaquín Pastor², Manuel Serrano⁴

Affiliations

¹ Tumour Suppression Group, Experimental Therapeutics Program and Confocal Microscopy Unit, Spanish National Cancer Research Centre (CNIO), Madrid, E28029, Spain.
² Experimental Therapeutics Program and.
³ Confocal Microscopy Unit, Spanish National Cancer Research Centre (CNIO), Madrid, E28029, Spain.
⁴ Tumour Suppression Group, Experimental Therapeutics Program and Confocal Microscopy Unit, Spanish National Cancer Research Centre (CNIO), Madrid, E28029, Spain [email protected].

PMID: 25344835
DOI: 10.1093/carcin/bgu220

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.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Acridines / administration & dosage
Acridines / chemistry
Acridines / pharmacology*
Blotting, Northern
Blotting, Western
Bone Neoplasms / drug therapy
Bone Neoplasms / genetics
Bone Neoplasms / metabolism*
Bone Neoplasms / pathology
Colonic Neoplasms / drug therapy
Colonic Neoplasms / genetics
Colonic Neoplasms / metabolism*
Colonic Neoplasms / pathology
DNA Damage / drug effects
Flow Cytometry
Fluorescent Antibody Technique
High-Throughput Screening Assays
Humans
Immunoprecipitation
Naphthyridines / administration & dosage
Naphthyridines / pharmacology*
Osteosarcoma / drug therapy
Osteosarcoma / genetics
Osteosarcoma / metabolism*
Osteosarcoma / pathology
Pharmaceutical Preparations / administration & dosage
Pharmaceutical Preparations / metabolism*
Proto-Oncogene Proteins c-mdm2 / genetics
Proto-Oncogene Proteins c-mdm2 / metabolism*
RNA, Messenger / genetics
RNA, Small Interfering / genetics
Real-Time Polymerase Chain Reaction
Reverse Transcriptase Polymerase Chain Reaction
Ribosomal Proteins / antagonists & inhibitors
Ribosomal Proteins / genetics
Ribosomal Proteins / metabolism*
Tumor Cells, Cultured
Tumor Suppressor Protein p53 / genetics
Tumor Suppressor Protein p53 / metabolism*

Substances

Acridines
CID-765471
Naphthyridines
Pharmaceutical Preparations
RNA, Messenger
RNA, Small Interfering
Ribosomal Proteins
TP53 protein, human
Tumor Suppressor Protein p53
ribosomal protein L11
MDM2 protein, human
Proto-Oncogene Proteins c-mdm2