title: ABC multidrug transporters: structure, function and role in chemoresistance.
abstract: Three ATP-binding cassette (ABC)-superfamily multidrug efflux pumps are known to be responsible for chemoresistance; P-glycoprotein (ABCB1), MRP1 (ABCC1) and ABCG2 (BCRP). These transporters play an important role in normal physiology by protecting tissues from toxic xenobiotics and endogenous metabolites. Hydrophobic amphipathic compounds, including many clinically used drugs, interact with the substrate-binding pocket of these proteins via flexible hydrophobic and H-bonding interactions. These efflux pumps are expressed in many human tumors, where they likely contribute to resistance to chemotherapy treatment. However, the use of efflux-pump modulators in clinical cancer treatment has proved disappointing. Single nucleotide polymorphisms in ABC drug-efflux pumps may play a role in responses to drug therapy and disease susceptibility. The effect of various genotypes and haplotypes on the expression and function of these proteins is not yet clear, and their true impact remains controversial.
authors.affiliation: University of Guelph, Department of Molecular & Cellular Biology, Guelph Ontario, N1G 2W1, Canada. fsharom@uoguelph.ca
authors.forename: Frances J
authors.initials: FJ
authors.lastname: Sharom
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000737:chemistry / Q000235:genetics* / Q000502:physiology*; D000818:Animals; D004351:Drug Resistance / Q000235:genetics* / Q000502:physiology*; D004358:Drug Therapy; D019450:Genes, MDR / Q000235:genetics; D006801:Humans; D026901:Membrane Transport Proteins / Q000378:metabolism; D004364:Pharmaceutical Preparations / Q000378:metabolism; D011110:Polymorphism, Genetic / Q000235:genetics; D011485:Protein Binding; D013329:Structure-Activity Relationship
chemical_list: D018528:ATP-Binding Cassette Transporters; D026901:Membrane Transport Proteins; D004364:Pharmaceutical Preparations