title: Cisplatin-induced apoptosis in 43-3B and 27-1 cells defective in nucleotide excision repair.
abstract: Cisplatin is a highly potent cytotoxic and genotoxic agent used in the chemotherapy of various types of tumors. Its cytotoxic effect is supposed to be due to the induction of intra- and interstrand DNA cross-links which are repaired via the nucleotide excision repair (NER) pathway. Here, we elucidated the mechanism of cisplatin-induced cytotoxicity in mutants derived from CHO-9 cells defective in NER. We compared 43-3B and 27-1 cells deficient for ERCC1 and ERCC3, respectively, with the corresponding wild-type and ERCC1 complemented 43-3B cells. It is shown that cells defective in ERCC1 are more sensitive than cells defective in ERCC3 with regard to cisplatin-induced reproductive cell death. ERCC1 and ERCC3 mutants showed a higher frequency of apoptosis and, to a lesser degree, necrosis compared to repair proficient cells. Induction of apoptosis in both ERCC1 and ERCC3 defective cells was accompanied by decline in Bcl-2 protein level, activation of caspases 8, 9 and 3 and poly(ADP-ribose)polymerase (PARP) cleavage. Since the mutant cells are defective in the repair of cisplatin-induced DNA lesions, the data demonstrate that non-repaired cisplatin-induced DNA adducts act as a trigger of the mitochondrial apoptotic pathway by down-regulation of Bcl-2 followed by caspase activation.
authors.affiliation: Division of Applied Toxicology, Institute of Toxicology, University of Mainz, Obere Zahlbacher Strasse 67, D-55131 Mainz, Germany.
authors.forename: T R
authors.initials: TR
authors.lastname: Dunkern
authors.forename: G
authors.initials: G
authors.lastname: Fritz
authors.forename: B
authors.initials: B
authors.lastname: Kaina
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D016466:CHO Cells; D053148:Caspase 3; D053181:Caspase 8; D053453:Caspase 9; D020169:Caspases / Q000378:metabolism; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D002945:Cisplatin / Q000494:pharmacology*; D006224:Cricetinae; D004260:DNA Repair; D004268:DNA-Binding Proteins / Q000235:genetics / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation; D029721:Drosophila Proteins; D004720:Endonucleases; D004789:Enzyme Activation; D009154:Mutation; D009336:Necrosis; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D011506:Proteins / Q000235:genetics / Q000502:physiology; D013997:Time Factors
chemical_list: D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D011506:Proteins; C078672:hay protein, Drosophila; D011065:Poly(ADP-ribose) Polymerases; D004720:Endonucleases; D053148:Caspase 3; D053181:Caspase 8; D053453:Caspase 9; D020169:Caspases; D002945:Cisplatin