title: Overexpression of cMOAT (MRP2/ABCC2) is associated with decreased formation of platinum-DNA adducts and decreased G2-arrest in melanoma cells resistant to cisplatin.
abstract: Resistance to various anti-neoplastic agents is a common observation in clinical management of melanoma. The biologic mechanisms conferring these different drug-resistant phenotypes, including resistance against the commonly used anti-cancer drug cisplatin, are unclear. In order to elucidate the role of the membrane adenosine triphosphate binding cassette-transporter cMOAT (canalicular multispecific anion transporter) (MRP2/ABCC2) in cisplatin resistance of melanoma, the expression of this protein was analyzed in the platinum drug-resistant cell line MeWo CIS 1. Cisplatin-resistant melanoma cells showed a distinct overexpression of cMOAT on mRNA and protein level. This observation was accompanied by a reduced formation of platinum-induced intrastrand cross-links in the nuclear DNA measured by an immunocytologic assay. This decrease in DNA platination was accompanied by an accelerated re-entry into the cell cycle after the typical cisplatin-induced G2 arrest, and a resistance to undergo apoptosis. Kinetics of formation and elimination of platinum-DNA adducts suggest that the DNA repair capacity for Pt-d(GpG) adducts was not elevated in platinum drug-resistant melanoma cells. The decrease in platinum-DNA adduct formation in cisplatin-resistant melanoma cells was rather a reflection of the protecting activity of the transporter cMOAT. In conclusion, the functional inhibition of cMOAT might be a promising strategy in the reversal of resistance to platinum-based anti-cancer drugs in human melanoma.
authors.affiliation: Institute of Cell Biology, University of Essen, Germany.
authors.forename: Bernd
authors.initials: B
authors.lastname: Liedert
authors.forename: Verena
authors.initials: V
authors.lastname: Materna
authors.forename: Dirk
authors.initials: D
authors.lastname: Schadendorf
authors.forename: Jürgen
authors.initials: J
authors.lastname: Thomale
authors.forename: Hermann
authors.initials: H
authors.lastname: Lage
mesh_terms: D000970:Antineoplastic Agents / Q000378:metabolism / Q000494:pharmacology*; D002945:Cisplatin / Q000378:metabolism / Q000494:pharmacology*; D018736:DNA Adducts / Q000378:metabolism*; D019008:Drug Resistance, Neoplasm; D016195:G2 Phase / Q000187:drug effects / Q000235:genetics; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D008545:Melanoma; D026901:Membrane Transport Proteins; D000089762:Multidrug Resistance-Associated Protein 2; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000235:genetics*; D010641:Phenotype; D010984:Platinum / Q000378:metabolism / Q000494:pharmacology; D012878:Skin Neoplasms; D014162:Transfection; D014407:Tumor Cells, Cultured / Q000166:cytology / Q000187:drug effects
chemical_list: D000970:Antineoplastic Agents; D002945:Cisplatin; D018736:DNA Adducts; D026901:Membrane Transport Proteins; D000089762:Multidrug Resistance-Associated Protein 2; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D010984:Platinum; C000715087:ABCC2 protein, human