title: Drug transport by breast cancer resistance protein.
abstract: BACKGROUND
  The ATP-binding cassette transporter ABCG2 is a well-known major mediator of multi-drug resistance in cancers. Beyond multi-drug resistance, experimental and recent clinical studies demonstrate a role for ABCG2 as a determinant of drug pharmacokinetic, safety and efficacy profiles.
  
  
  METHODS
  The clinical evidence of the role of ABCG2 in pharmacokinetics and pharmacodynamics is reviewed. Key questions that arise from the perspective of preclinical drug evaluation are addressed, including the structure of ABCG2 and mechanisms of drug-transporter interactions, mechanisms responsible for the polyspecificity of ABCG2, methods suitable for studying drug-ABCG2 interactions in vitro and in silico prediction of ABCG2 substrates and inhibitors.
  
  
  RESULTS
  An update on current knowledge of the importance of ABCG2 in drug disposition with special emphasis on drug development.
  
  
  CONCLUSIONS
  The field of drug-ABCG2 interaction is rapidly advancing and beginning to expand into clinical practice. However, the structural understanding of drug binding and transport by ABCG2 is still incomplete. Incorporation of novel concepts of drug-transporter interactions such as electrostatic funneling might help explain the multispecificity of ABCG2 and enable in silico predictions.
authors.affiliation: University of Erlangen-Nuremberg, Institute of Experimental and Clinical Pharmacology and Toxicology, Fahrstr. 17, 91054 Erlangen, Germany.
authors.forename: Maren
authors.initials: M
authors.lastname: Poguntke
authors.forename: Eszter
authors.initials: E
authors.lastname: Hazai
authors.forename: Martin F
authors.initials: MF
authors.lastname: Fromm
authors.forename: Oliver
authors.initials: O
authors.lastname: Zolk
mesh_terms: D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters / Q000378:metabolism*; D000818:Animals; D000970:Antineoplastic Agents / Q000009:adverse effects / Q000493:pharmacokinetics / Q000494:pharmacology*; D001692:Biological Transport; D001943:Breast Neoplasms / Q000188:drug therapy*; D002986:Clinical Trials as Topic; D015195:Drug Design; D004353:Drug Evaluation, Preclinical; D018432:Drug Resistance, Multiple; D019008:Drug Resistance, Neoplasm; D005260:Female; D006801:Humans; D009363:Neoplasm Proteins / Q000378:metabolism*
chemical_list: C116614:ABCG2 protein, human; D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters; D000970:Antineoplastic Agents; D009363:Neoplasm Proteins