6,7-dimethoxycoumarin attenuated cisplatin-induced DNA interstrand crosslink and DNA-protein crosslink in primary cultured rabbit kidney proximal tubular cells.
OBJECTIVE
To study the mechanism of cisplatin interaction with DNA, and the attenuating effects of 6,7-dimethoxycoumarin (DMOC) on crosslink.


METHODS
Primary cultured rabbit kidney proximal tubular cells (PTC) were established. DNA interstrand crosslink was assayed with ethidium bromide binding and DNA-protein crosslink with 125I-postlabelling. PTC were incubated with cisplatin for 24 h. DMOC was preincubated with PTC for 24 h, and cisplatin (26 mumol.L-1) was added into culture and incubated for another 24 h.


RESULTS
Cisplatin induced formation of DNA interstrand crosslink (13, 26, 52, and 78 mumol.L-1) and DNA-protein crosslink (26, 52, and 78 mumol.L-1) (P < 0.01). DNA interstrand crosslink in DMOC (0.4, 4, and 8 mg.L-1) and DNA-protein crosslink in DMOC (4, 8 mg.L-1) were less than those in cisplatin group (26 mumol.L-1), respectively (P < 0.01).


CONCLUSIONS
The mechanisms of cisplatin interaction with DNA in PTC were DNA interstrand crosslink and DNA-protein crosslink, and DMOC attenuated these effects in vitro.
Liu
S J
SJ
Department of Clinical Pharmacology, Xin Qiao Hospital, Third Military Medical University, Chongqing, China.
Zhou
S W
SW
D000818:Animals; D002478:Cells, Cultured; D002945:Cisplatin / Q000037:antagonists & inhibitors / Q000633:toxicity*; D003374:Coumarins / Q000494:pharmacology*; D004247:DNA / Q000032:analysis / Q000187:drug effects; D004249:DNA Damage; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000187:drug effects*; D005260:Female; D007687:Kidney Tubules, Proximal / Q000737:chemistry* / Q000166:cytology; D008297:Male; D011817:Rabbits
D003374:Coumarins; D004268:DNA-Binding Proteins; D004247:DNA; C018145:scoparone; D002945:Cisplatin