title: Characterization of chemoresistance mechanisms in a series of cisplatin-resistant transitional carcinoma cell lines.
abstract: We explored the mechanisms of cisplatin resistance in a series of bladder transitional carcinoma cells that are either sensitive or progressively resistant to cisplatin. Resistant lines were raised by chronic exposure of the parental cells to progressively increased concentrations of cisplatin. The cisplatin IC50s of the sensitive and the three resistant cells were 4.3, 25.0, 40.4, and 52.2 microM, respectively. The expressions of glutathione S-transferase pi (GST-pi) and multidrug resistance-associated protein (MRP) were enhanced in a dose-response manner as cells acquired progressive cisplatin resistance. Expression of mdr-1 transcript was detected in the three resistant lines but not in the sensitive line. Glutathione contents were increased in resistant cells, yet the trend of increase did not reach statistical significance (p = 0.061). In conclusion, transitional carcinoma cells may gain cisplatin resistance through multiple pathways including up-regulation of GST-pi, MRP and possibly mdr-1. Glutathione contents may play a less significant role in cisplatin chemoresistance.
authors.affiliation: Department of Urology, National Taiwan University Hospital, Taipei, Republic of China.
authors.forename: T C
authors.initials: TC
authors.lastname: Hour
authors.forename: J
authors.initials: J
authors.lastname: Chen
authors.forename: C Y
authors.initials: CY
authors.lastname: Huang
authors.forename: J Y
authors.initials: JY
authors.lastname: Guan
authors.forename: S H
authors.initials: SH
authors.lastname: Lu
authors.forename: C Y
authors.initials: CY
authors.lastname: Hsieh
authors.forename: Y S
authors.initials: YS
authors.lastname: Pu
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000235:genetics / Q000378:metabolism*; D018528:ATP-Binding Cassette Transporters / Q000378:metabolism*; D000970:Antineoplastic Agents / Q000378:metabolism / Q000494:pharmacology*; D015153:Blotting, Western / Q000379:methods; D002295:Carcinoma, Transitional Cell / Q000188:drug therapy*; D002945:Cisplatin / Q000378:metabolism / Q000494:pharmacology*; D019008:Drug Resistance, Neoplasm; D004354:Drug Screening Assays, Antitumor; D005978:Glutathione / Q000378:metabolism; D051549:Glutathione S-Transferase pi; D005982:Glutathione Transferase / Q000235:genetics / Q000378:metabolism*; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism*; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured; D001749:Urinary Bladder Neoplasms / Q000188:drug therapy*
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D018528:ATP-Binding Cassette Transporters; D000970:Antineoplastic Agents; D002945:Cisplatin; D005978:Glutathione; D051549:Glutathione S-Transferase pi; D005982:Glutathione Transferase; D007527:Isoenzymes; D027425:ATP-Binding Cassette, Sub-Family C Proteins