Homologous recombination is involved in repair of chromium-induced DNA damage in mammalian cells

Mutat Res. 2006 Jul 25;599(1-2):116-23. doi: 10.1016/j.mrfmmm.2006.02.001. Epub 2006 Mar 27.

Abstract

Chromium is a potent human carcinogen, probably because of its well-documented genotoxic effects. Chromate (Cr[VI]) causes a wide range of DNA lesions, including DNA crosslinks and strand breaks, presumably due to the direct and indirect effects of DNA oxidation. Homologous recombination repair (HRR) is important for error-free repair of lesions occurring at replication forks. Here, we show that HR deficient cell lines irs1SF and V-C8, deficient in XRCC3 and BRCA2, respectively, are hypersensitive to Cr[VI], implicating this repair pathway in repair of Cr[VI] damage. Furthermore, we find that Cr[VI] causes DNA double-strand breaks and triggers both Rad51 foci formation and induction of HRR. Collectively, these data suggest that HRR is important in repair of Cr[VI]-induced DNA damage. In addition, we find that ERCC1, XRCC1 and DNA-PKcs defective cells are hypersensitive to Cr[VI], indicating that several repair pathways cooperate in repairing Cr[VI]-induced DNA damage.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Line
  • Chromium / toxicity*
  • Chromosome Breakage
  • Cricetinae
  • DNA Damage*
  • DNA Repair / genetics*
  • DNA-Binding Proteins / deficiency
  • DNA-Binding Proteins / genetics
  • Endonucleases / deficiency
  • Endonucleases / genetics
  • Genotype
  • Models, Biological
  • Rad51 Recombinase / metabolism
  • Recombination, Genetic*
  • X-ray Repair Cross Complementing Protein 1

Substances

  • DNA-Binding Proteins
  • X-ray Repair Cross Complementing Protein 1
  • XRCC1 protein, human
  • Chromium
  • Rad51 Recombinase
  • Endonucleases