title: Drug resistance-associated changes in sphingolipids and ABC transporters occur in different regions of membrane domains.
abstract: We have recently shown that two ATP binding cassette (ABC) transporters are enriched in Lubrol-resistant noncaveolar membrane domains in multidrug-resistant human cancer cells [Hinrichs, J. W. J., K. Klappe, I. Hummel, and J. W. Kok. 2004. ATP-binding cassette transporters are enriched in non-caveolar detergent-insoluble glycosphingolipid-enriched membrane domains (DIGs) in human multidrug-resistant cancer cells. J. Biol. Chem. 279: 5734-5738]. Here, we show that aminophospholipids are relatively enriched in Lubrol-resistant membrane domains compared with Triton X-100-resistant membrane domains, whereas sphingolipids are relatively enriched in the latter. Moreover, Lubrol-resistant membrane domains contain more protein and lipid mass. Based on these results, we postulate a model for detergent-insoluble glycosphingolipid-enriched membrane domains consisting of a Lubrol-insoluble/Triton X-100-insoluble region and a Lubrol-insoluble/Triton X-100-soluble region. The latter region contains most of the ABC transporters as well as lipids known to be necessary for their efflux activity. Compared with drug-sensitive cells, the detergent-insoluble glycosphingolipid-enriched membrane domains (DIGs) in drug-resistant cells differ specifically in sphingolipid content and not in protein, phospholipid, or cholesterol content. In drug-resistant cells, sphingolipids with specific fatty acids (especially C24:1) are enriched in these membrane domains. Together, these data show that multidrug resistance-associated changes in both sphingolipids and ABC transporters occur in DIGs, but in different regions of these domains.
authors.affiliation: Department of Cell Biology, Section of Membrane Cell Biology, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: John W J
authors.initials: JW
authors.lastname: Hinrichs
authors.forename: Karin
authors.initials: K
authors.lastname: Klappe
authors.forename: Manon
authors.initials: M
authors.lastname: van Riezen
authors.forename: Jan W
authors.initials: JW
authors.lastname: Kok
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000378:metabolism; D018528:ATP-Binding Cassette Transporters / Q000378:metabolism*; D002460:Cell Line; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000378:metabolism*; D019742:Chemokines, CC / Q000378:metabolism; D002784:Cholesterol / Q000378:metabolism; D002853:Chromatography, Liquid; D003902:Detergents / Q000494:pharmacology; D004351:Drug Resistance; D019008:Drug Resistance, Neoplasm; D005227:Fatty Acids / Q000378:metabolism; D006028:Glycosphingolipids / Q000378:metabolism; D006801:Humans; D015151:Immunoblotting; D008055:Lipids / Q000737:chemistry; D017830:Octoxynol / Q000494:pharmacology; D010743:Phospholipids / Q000737:chemistry; D011092:Polyethylene Glycols / Q000494:pharmacology; D017434:Protein Structure, Tertiary; D021241:Spectrometry, Mass, Electrospray Ionization; D013107:Sphingolipids / Q000378:metabolism*
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D018528:ATP-Binding Cassette Transporters; D019742:Chemokines, CC; D003902:Detergents; D005227:Fatty Acids; D006028:Glycosphingolipids; D008055:Lipids; D010743:Phospholipids; D013107:Sphingolipids; C070959:Ccl6 protein, mouse; D011092:Polyethylene Glycols; C005092:lubrol; D017830:Octoxynol; D002784:Cholesterol