title: Serine protease inhibition and mitochondrial dysfunction associated with cisplatin resistance in human tumor cell lines: targets for therapy.
abstract: Indicators of mitochondrial function were studied in two different cell culture models of cis-diamminedichloroplatinum-II (CDDP) resistance: the intrinsically resistant human ovarian cancer cell line CI-80-13S, and resistant clones (HeLa-S1a and HeLa-S1b) generated by stable expression of the serine protease inhibitor-plasminogen activator inhibitor type-2 (PAI-2), in the human cervical cancer cell line HeLa. In both models, CDDP resistance was associated with sensitivity to killing by adriamycin, etoposide, auranofin, bis[1,2-bis(diphenylphosphino)ethane]gold(I) chloride ([Au(DPPE)2]Cl), CdCl2 and the mitochondrial inhibitors rhodamine-123 (Rh123), dequalinium chloride (DeCH), tetraphenylphosphonium (TPP), and ethidium bromide (EtBr) and with lower constitutive levels of ATP. Unlike the HeLa clones, CI-80-13S cells were additionally sensitive to chloramphenicol, 1-methyl-4-phenylpyridinium ion (MPP+), rotenone, thenoyltrifluoroacetone (TTFA), and antimycin A, and showed poor reduction of 1-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT), suggesting a deficiency in NADH dehydrogenase and/or succinate dehydrogenase activities. Total platinum uptake and DNA-bound platinum were slightly lower in CI-80-13S than in sensitive cells. The HeLa-S1a and HeLa-S1b clones, on the other hand, showed poor reduction of triphenyltetrazolium chloride (TTC), indicative of low cytochrome c oxidase activity. Total platinum uptake by HeLa-Sla was similar to HeLa, but DNA-bound platinum was much lower than for the parent cell line. The mitochondria of CI-80-13S and HeLa-S1a showed altered morphology and were fewer in number than those of JAM and HeLa. In both models, CDDP resistance was associated with less platinum accumulation and with mitochondrial and membrane defects, brought about one case with expression of a protease inhibitor which is implicated in tumor progression. Such markers may identify tumors suitable for treatment with gold phosphine complexes or other mitochondrial inhibitors.
authors.affiliation: Department of Obstetrics and Gynaecology, University of Queensland, Australia.
authors.forename: Y
authors.initials: Y
authors.lastname: Dong
authors.forename: S J
authors.initials: SJ
authors.lastname: Berners-Price
authors.forename: D R
authors.initials: DR
authors.lastname: Thorburn
authors.forename: T
authors.initials: T
authors.lastname: Antalis
authors.forename: J
authors.initials: J
authors.lastname: Dickinson
authors.forename: T
authors.initials: T
authors.lastname: Hurst
authors.forename: L
authors.initials: L
authors.lastname: Qiu
authors.forename: S K
authors.initials: SK
authors.lastname: Khoo
authors.forename: P G
authors.initials: PG
authors.lastname: Parsons
mesh_terms: D000255:Adenosine Triphosphate / Q000032:analysis; D000970:Antineoplastic Agents / Q000494:pharmacology*; D002945:Cisplatin / Q000494:pharmacology*; D004273:DNA, Neoplasm / Q000378:metabolism; D004351:Drug Resistance; D042963:Electron Transport Complex II; D014450:Electron Transport Complex III / Q000378:metabolism; D005978:Glutathione / Q000032:analysis; D006801:Humans; D008928:Mitochondria / Q000187:drug effects* / Q000201:enzymology; D009097:Multienzyme Complexes / Q000378:metabolism; D016660:NAD(P)H Dehydrogenase (Quinone) / Q000378:metabolism; D010088:Oxidoreductases / Q000378:metabolism; D010984:Platinum / Q000378:metabolism; D015842:Serine Proteinase Inhibitors / Q000494:pharmacology*; D013385:Succinate Dehydrogenase / Q000378:metabolism; D013778:Tetrazolium Salts; D013844:Thiazoles; D014407:Tumor Cells, Cultured / Q000187:drug effects
chemical_list: D000970:Antineoplastic Agents; D004273:DNA, Neoplasm; D009097:Multienzyme Complexes; D015842:Serine Proteinase Inhibitors; D013778:Tetrazolium Salts; D013844:Thiazoles; D010984:Platinum; D000255:Adenosine Triphosphate; D010088:Oxidoreductases; D042963:Electron Transport Complex II; D013385:Succinate Dehydrogenase; D016660:NAD(P)H Dehydrogenase (Quinone); D014450:Electron Transport Complex III; C022616:thiazolyl blue; D005978:Glutathione; D002945:Cisplatin