title: Breast cancer resistance protein (BCRP/ABCG2) induces cellular resistance to HIV-1 nucleoside reverse transcriptase inhibitors.
abstract: Breast cancer resistance protein (BCRP/ABCG2) is a novel member of ATP- binding cassette transporters, which induce multidrug resistance in cancer cells. We found that a high level of BCRP expression in CD4+ T cells conferred cellular resistance to human immunodeficiency virus type-1 (HIV-1) nucleoside reverse transcriptase inhibitors. The cell line MT-4/DOX 500 was established through the long-term culture of MT-4 cells in the presence of doxorubicin (DOX) and had reduced sensitivity to not only DOX but also zidovudine (AZT). MT-4/DOX 500 cells showed reduced intracellular accumulation and retention of DOX and increased ATP-dependent rhodamine 123 efflux. The cells were also resistant to several anticancer agents such as mitoxantrone, 7-ethyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxycamptothecin, and 7-ethyl-10-hydroxycamptothecin. AZT was 7.5-fold less inhibitory to HIV-1 replication in MT-4/DOX 500 cells than in MT-4 cells. Furthermore, the anti-HIV-1 activity of lamivudine was severely impaired in MT-4/DOX 500 cells. In contrast, the antiviral activity of non-nucleoside reverse transcriptase inhibitors and protease inhibitors was not affected in the cells. MT-4/DOX 500 cells expressed glycosylated BCRP but not P-glycoprotein (ABCB1), multidrug resistance protein 1, 2, or 4 (ABCC1, -2, or -4), or lung resistance-related protein. In addition, the BCRP-specific inhibitor fumitremorgin C completely abolished the resistance of MT-4/DOX 500 cells to AZT as well as to DOX. An analysis for intracellular metabolism of AZT suggests that the resistance is attributed to the increase of ATP-dependent efflux of its metabolites, presumably AZT 5'-monophosphate, in MT-4/DOX 500 cells.
authors.affiliation: Division of Human Retroviruses, Center for Chronic Viral Diseases, Faculty of Medicine, Kagoshima University, Kagoshima, Japan. baba@m.kufm.kagoshima-u.ac.jp
authors.forename: Xin
authors.initials: X
authors.lastname: Wang
authors.forename: Tatsuhiko
authors.initials: T
authors.lastname: Furukawa
authors.forename: Takao
authors.initials: T
authors.lastname: Nitanda
authors.forename: Mika
authors.initials: M
authors.lastname: Okamoto
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Sugimoto
authors.forename: Shin-Ichi
authors.initials: S
authors.lastname: Akiyama
authors.forename: Masanori
authors.initials: M
authors.lastname: Baba
mesh_terms: D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D019380:Anti-HIV Agents / Q000494:pharmacology*; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects / Q000502:physiology*; D002478:Cells, Cultured; D004317:Doxorubicin / Q000494:pharmacology; D019008:Drug Resistance, Neoplasm; D024882:Drug Resistance, Viral / Q000502:physiology*; D054303:HIV Reverse Transcriptase / Q000037:antagonists & inhibitors; D015497:HIV-1 / Q000187:drug effects* / Q000201:enzymology; D006801:Humans; D007211:Indoles / Q000494:pharmacology; D019259:Lamivudine / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D009363:Neoplasm Proteins; D018894:Reverse Transcriptase Inhibitors / Q000494:pharmacology*; D015215:Zidovudine / Q000494:pharmacology
chemical_list: C116614:ABCG2 protein, human; D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters; D019380:Anti-HIV Agents; D007211:Indoles; D009363:Neoplasm Proteins; D018894:Reverse Transcriptase Inhibitors; D019259:Lamivudine; D015215:Zidovudine; D004317:Doxorubicin; C010522:tryptoquivaline; D054303:HIV Reverse Transcriptase