title: Effect of multidrug resistance-reversing agents on transporting activity of human canalicular multispecific organic anion transporter.
abstract: The canalicular multispecific organic anion transporter (cMOAT), also termed MRP2, is a recently identified ATP-binding cassette transporter. We previously established stable human cMOAT cDNA-transfected cells, LLC/cMOAT-1 from LLC-PK1 cells, and LLC/CMV cells that were transfected with an empty vector. We found that LLC/cMOAT-1 cells have increased resistance to vincristine (VCR), 7-ethyl-10-hydroxy-camptothecin, and cisplatin but not to etoposide. The multidrug resistance-reversing agents cyclosporin A (CsA) and 2-[4-(diphenylmethyl)-1-piperazinyl]-5-(trans-4,6-dimethyl-1,3, 2-dioxaphosphorinan-2-yl)-2, 6-dimethyl-4-(3-nitrophenyl)-3-pyridinecarboxylate P-oxide (PAK-104P) almost completely reversed the resistance to VCR, 7-ethyl-10-hydroxy-camptothecin, and cisplatin of LLC/cMOAT-1 cells; and DL-buthionine-(S,R)-sulfoximine, (3'-oxo-4-butenyl-4-methyl-threonine(1), (valine(2)) cyclosporin (PSC833), and 3-([(3-(2-[7-chloro-2-quinolinyl]ethenyl)phenyl)-((3-dimethylamino-3- oxopropyl)-thio)-methyl]thio)propanoic acid (MK571) partially reversed the resistance to these drugs. CsA and PAK-104P at 10 microM enhanced the accumulation of VCR in LLC/cMOAT-1 cells almost to the level in LLC/CMV cells without the agents. The efflux of VCR from LLC/cMOAT-1 cells was enhanced compared with LLC/CMV cells and inhibited by CsA and PAK-104P. Transport of leukotriene C(4) (LTC(4)) and S-(2, 4-dinitrophenyl)glutathione also was studied with membrane vesicles prepared from these cells. LTC(4) and S-(2, 4-dinitrophenyl)glutathione were actively transported into membrane vesicles prepared from LLC/cMOAT-1 cells. The K(m) and V(max) values for the uptake of LTC(4) by the LLC/cMOAT-1 membrane vesicles were 0. 26 +/- 0.05 microM and 7.48 +/- 0.67 pmol/min/mg protein, respectively. LTC(4) transport was competitively inhibited by PAK-104P, CsA, MK571, and PSC833, with K(i) values of 3.7, 4.7, 13.1, and 28.9 microM, respectively. These findings demonstrate that cMOAT confers a novel drug-resistance phenotype. CsA and PAK-104P may be useful for reversing cMOAT-mediated drug resistance in tumors.
authors.affiliation: Department of Cancer Chemotherapy, Institute for Cancer Research, Faculty of Medicine, Kagoshima University, Sakuragaoka Kagoshima, Japan.
authors.forename: Z S
authors.initials: ZS
authors.lastname: Chen
authors.forename: T
authors.initials: T
authors.lastname: Kawabe
authors.forename: M
authors.initials: M
authors.lastname: Ono
authors.forename: S
authors.initials: S
authors.lastname: Aoki
authors.forename: T
authors.initials: T
authors.lastname: Sumizawa
authors.forename: T
authors.initials: T
authors.lastname: Furukawa
authors.forename: T
authors.initials: T
authors.lastname: Uchiumi
authors.forename: M
authors.initials: M
authors.lastname: Wada
authors.forename: M
authors.initials: M
authors.lastname: Kuwano
authors.forename: S I
authors.initials: SI
authors.lastname: Akiyama
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D027321:Anion Transport Proteins; D000970:Antineoplastic Agents / Q000494:pharmacology; D001692:Biological Transport / Q000187:drug effects; D002352:Carrier Proteins / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D003498:Cyclic P-Oxides / Q000494:pharmacology*; D016572:Cyclosporine / Q000494:pharmacology*; D004347:Drug Interactions; D018432:Drug Resistance, Multiple / Q000502:physiology*; D005978:Glutathione / Q000031:analogs & derivatives / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D017997:Leukotriene C4 / Q000378:metabolism; D009539:Nicotinic Acids / Q000494:pharmacology*; D009994:Osmolar Concentration; D011422:Propionates / Q000494:pharmacology; D011804:Quinolines / Q000494:pharmacology; D013552:Swine; D014162:Transfection; D014316:Tritium; D014750:Vincristine / Q000494:pharmacology
chemical_list: D027321:Anion Transport Proteins; D000970:Antineoplastic Agents; D002352:Carrier Proteins; D003498:Cyclic P-Oxides; D009539:Nicotinic Acids; D011422:Propionates; D011804:Quinolines; D014316:Tritium; C103821:PAK 104P; C030190:S-(2,4-dinitrophenyl)glutathione; D017997:Leukotriene C4; D014750:Vincristine; C059141:verlukast; D016572:Cyclosporine; D000255:Adenosine Triphosphate; D005978:Glutathione