DNA repair protein Ku80 suppresses chromosomal aberrations and malignant transformation

Nature. 2000 Mar 30;404(6777):510-4. doi: 10.1038/35006670.


Cancer susceptibility genes have been classified into two groups: gatekeepers and caretakers. Gatekeepers are genes that control cell proliferation and death, whereas caretakers are DNA repair genes whose inactivation leads to genetic instability. Abrogation of both caretaker and gatekeeper function markedly increases cancer susceptibility. Although the importance of Ku80 in DNA double-strand break repair is well established, neither Ku80 nor other components of the non-homologous end-joining pathway are known to have a caretaker role in maintaining genomic stability. Here we show that mouse cells deficient for Ku80 display a marked increase in chromosomal aberrations, including breakage, translocations and aneuploidy. Despite the observed chromosome instabilities, Ku80-/- mice have only a slightly earlier onset of cancer. Loss of p53 synergizes with Ku80 to promote tumorigenesis such that all Ku80-/- p53-/- mice succumb to disseminated pro-B-cell lymphoma before three months of age. Tumours result from a specific set of chromosomal translocations and gene amplifications involving IgH and c-Myc, reminiscent of Burkitt's lymphoma. We conclude that Ku80 is a caretaker gene that maintains the integrity of the genome by a mechanism involving the suppression of chromosomal rearrangements.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens, Nuclear*
  • Cell Line
  • Cell Transformation, Neoplastic* / genetics
  • Chromosome Aberrations*
  • Cloning, Molecular
  • DNA / radiation effects
  • DNA Damage
  • DNA Helicases*
  • DNA Repair*
  • DNA-Binding Proteins / deficiency
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / physiology*
  • Female
  • Gamma Rays
  • Genes, p53
  • Karyotyping
  • Ku Autoantigen
  • Lymphoma / genetics
  • Male
  • Mice
  • Mutagenesis
  • Nuclear Proteins / deficiency
  • Nuclear Proteins / genetics
  • Nuclear Proteins / physiology*
  • Translocation, Genetic


  • Antigens, Nuclear
  • DNA-Binding Proteins
  • Nuclear Proteins
  • DNA
  • DNA Helicases
  • XRCC5 protein, human
  • Xrcc6 protein, human
  • Xrcc6 protein, mouse
  • Ku Autoantigen