title: Bufalin influences the repair of X-ray-induced DNA breaks in Chinese hamster cells.
abstract: The bufadienolide bufalin, a component of the Chinese medicine chan'su, has been reported to selectively inhibit the growth of various lines of human cancer cells, due at least in part to its specific effect on topoisomerase (topo) II. We have treated Chinese hamster ovary (CHO) cells with doses of bufalin that result in a dramatic reduction in both the level and catalytic activity of topo II without any concomitant induction of DNA damage, as assessed by the comet assay. When cells were pre-treated with bufalin and then irradiated with X-rays, a follow-up study revealed that the kinetics of DNA repair was clearly affected, with a general delay in the restoration of DNA to the situation observed in non-irradiated controls. The possible involvement of topo II in radiation damage repair is discussed.
authors.affiliation: Department of Cell Biology, Faculty of Biology, University of Seville, 41012, Seville, Spain.
authors.forename: Nuria
authors.initials: N
authors.lastname: Pastor
authors.forename: Felipe
authors.initials: F
authors.lastname: Cortés
mesh_terms: D000818:Animals; D002018:Bufanolides / Q000494:pharmacology*; D016466:CHO Cells / Q000187:drug effects / Q000201:enzymology / Q000528:radiation effects; D006224:Cricetinae; D004247:DNA / Q000528:radiation effects*; D004249:DNA Damage / Q000187:drug effects* / Q000528:radiation effects; D004260:DNA Repair / Q000187:drug effects* / Q000528:radiation effects; D004250:DNA Topoisomerases, Type II / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors; D014965:X-Rays
chemical_list: D002018:Bufanolides; D004791:Enzyme Inhibitors; D004247:DNA; D004250:DNA Topoisomerases, Type II; D000254:Sodium-Potassium-Exchanging ATPase; C022777:bufalin