Camptothecin enhances random integration of transfected DNA into the genome of mammalian cells.
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.
Shcherbakova
O G
OG
Molecular and Radiation Biophysics Division, Petersburg Nuclear Physics Institute, 188350, Gatchina, Russia. olia@omrb.pnpi.spb.ru
Filatov
M V
MV
D000818:Animals; D002166:Camptothecin / Q000494:pharmacology*; D002460:Cell Line; D006224:Cricetinae; D004264:DNA Topoisomerases, Type I / Q000378:metabolism*; D018274:Electroporation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D051379:Mice; D010957:Plasmids; D011995:Recombination, Genetic / Q000187:drug effects; D013997:Time Factors; D059004:Topoisomerase I Inhibitors; D014162:Transfection / Q000187:drug effects; D014407:Tumor Cells, Cultured; D015854:Up-Regulation
D004791:Enzyme Inhibitors; D059004:Topoisomerase I Inhibitors; D004264:DNA Topoisomerases, Type I; D002166:Camptothecin