The nucleolus as a fundamental regulator of the p53 response and a new target for cancer therapy

Biochim Biophys Acta. 2015 Jul;1849(7):821-9. doi: 10.1016/j.bbagrm.2014.10.007. Epub 2014 Nov 11.

Abstract

Background: Recent studies have highlighted the fundamental role that key oncogenes such as MYC, RAS and PI3K occupy in driving RNA Polymerase I transcription in the nucleolus. In addition to maintaining essential levels of protein synthesis, hyperactivated ribosome biogenesis and nucleolar function plays a central role in suppressing p53 activation in response to oncogenic stress. Consequently, disruption of ribosome biogenesis by agents such as the small molecule inhibitor of RNA Polymerase I transcription, CX-5461, has shown unexpected, potent, and selective effects in killing tumour cells via disruption of nucleolar function leading to activation of p53, independent of DNA damage.

Scope of review: This review will explore the mechanism of DNA damage-independent activation of p53 via the nucleolar surveillance pathway and how this can be utilised to design novel cancer therapies.

Major conclusion and general significance: Non-genotoxic targeting of nucleolar function may provide a new paradigm for treatment of a broad range of oncogene-driven malignancies with improved therapeutic windows. This article is part of a Special Issue entitled: Translation and Cancer.

Keywords: Cancer therapy; Nucleolar stress; Nucleolus; RNA polymerase I inhibition; p53.

Publication types

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

MeSH terms

  • Animals
  • Benzothiazoles / pharmacology
  • Cell Nucleolus / genetics
  • Cell Nucleolus / metabolism*
  • Cell Nucleolus / pathology
  • DNA Damage
  • Humans
  • Naphthyridines / pharmacology
  • Neoplasms / genetics
  • Neoplasms / metabolism
  • Neoplasms / pathology
  • Neoplasms / therapy*
  • Phosphatidylinositol 3-Kinases / genetics
  • Phosphatidylinositol 3-Kinases / metabolism
  • Proto-Oncogene Proteins c-myc / genetics
  • Proto-Oncogene Proteins c-myc / metabolism
  • RNA Polymerase I / antagonists & inhibitors
  • RNA Polymerase I / genetics
  • RNA Polymerase I / metabolism*
  • Ribosomes / genetics
  • Ribosomes / metabolism*
  • Ribosomes / pathology
  • Transcription, Genetic*
  • Tumor Suppressor Protein p53 / genetics
  • Tumor Suppressor Protein p53 / metabolism*
  • ras Proteins / genetics
  • ras Proteins / metabolism

Substances

  • Benzothiazoles
  • CX 5461
  • MYC protein, human
  • Naphthyridines
  • Proto-Oncogene Proteins c-myc
  • TP53 protein, human
  • Tumor Suppressor Protein p53
  • Phosphatidylinositol 3-Kinases
  • RNA Polymerase I
  • ras Proteins