Camptothecin enhances random integration of transfected DNA into the genome of mammalian cells

Biochim Biophys Acta. 2000 Jan 10;1495(1):1-3. doi: 10.1016/s0167-4889(99)00151-2.

Abstract

In order to study the involvement of DNA topoisomerase I (top1) in recombination, we examined the effect of the anti-neoplastic drug camptothecin, which selectively poisons top1 by trapping top1-cleavable complexes on integration of exogenic vector into the genome of mammalian cells. We transfected mouse F9 teratocarcinoma cells as well as Chinese hamster V79 cells with a plasmid carrying a selectable neo gene treated with camptothecin, and determined the frequency of neo+ (G418(R)) colonies. We found that treatment with camptothecin for as short a time as 4 h after electroporation resulted in a 4- to 33-fold stimulation of plasmid integration into the recipient genome via non-homologous recombination. These results imply that top1-cleavable complexes trapped by camptothecin could be potentially recombinogenic structures and could stimulate non-homologous recombination in vivo, promoting the integration of transfected plasmids into mammalian genome.

MeSH terms

  • Animals
  • Camptothecin / pharmacology*
  • Cell Line
  • Cricetinae
  • DNA Topoisomerases, Type I / metabolism*
  • Electroporation
  • Enzyme Inhibitors / pharmacology
  • Mice
  • Plasmids
  • Recombination, Genetic / drug effects
  • Time Factors
  • Topoisomerase I Inhibitors
  • Transfection / drug effects
  • Tumor Cells, Cultured
  • Up-Regulation

Substances

  • Enzyme Inhibitors
  • Topoisomerase I Inhibitors
  • DNA Topoisomerases, Type I
  • Camptothecin