title: Chronic imatinib mesylate exposure leads to reduced intracellular drug accumulation by induction of the ABCG2 (BCRP) and ABCB1 (MDR1) drug transport pumps.
abstract: Imatinib mesylate is a selective tyrosine kinase inhibitor that is successfully used in the treatment of Philadelphia-positive chronic and acute leukaemia's, and gastrointestinal stromal tumors. We investigated whether the intended chronic oral administration of imatinib might lead to the induction of the intestinal ABC transport proteins ABCB1, ABCC1 (MRP1), ABCC2 (MRP2) and ABCG2. Using Caco2 cells as an in vitro model for intestinal drug transport, we found that continuous exposure (up to 100 days) with imatinib (10 microM) specifically upregulates the expression of ABCG2 (maximal approximately 17-fold) and ABCB1 (maximal approximately 5-fold). The induction of gene expression appeared to be biphasic in time, with a significant increase in ABCG2 and ABCB1 at day 3 and day 25, respectively, and was not mediated through activation of the human orphan nuclear receptor SXR/NR1I2. Importantly, chronic imatinib exposure of Caco2 cells resulted in a approximately 50% decrease in intracellular accumulation of imatinib, probably by enhanced ABCG2- and ABCB1-mediated efflux, as a result of upregulated expression of these drug pumps. Both ABCG2 and ABCB1 are normally expressed in the gastrointestinal tract and it might be anticipated that drug-induced upregulation of these intestinal pumps could reduce the oral bioavailability of imatinib, representing a novel mechanism of acquired pharmacokinetic drug resistance in cancer patients that are chronically treated with imatinib.
authors.affiliation: Department of Medical Oncology, Erasmus Medical Center Rotterdam-Josephine Nefkens Institute, Rotterdam, The Netherlands.
authors.forename: Herman
authors.initials: H
authors.lastname: Burger
authors.forename: Hans
authors.initials: H
authors.lastname: van Tol
authors.forename: Mariël
authors.initials: M
authors.lastname: Brok
authors.forename: Erik A C
authors.initials: EA
authors.lastname: Wiemer
authors.forename: Ernst A
authors.initials: EA
authors.lastname: de Bruijn
authors.forename: Gunther
authors.initials: G
authors.lastname: Guetens
authors.forename: Gert
authors.initials: G
authors.lastname: de Boeck
authors.forename: Alex
authors.initials: A
authors.lastname: Sparreboom
authors.forename: Jaap
authors.initials: J
authors.lastname: Verweij
authors.forename: Kees
authors.initials: K
authors.lastname: Nooter
mesh_terms: D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters / Q000096:biosynthesis* / Q000235:genetics; D000284:Administration, Oral; D000818:Animals; D000970:Antineoplastic Agents / Q000008:administration & dosage*; D001549:Benzamides; D001692:Biological Transport; D019556:COS Cells; D002522:Chlorocebus aethiops; D000090702:Constitutive Androstane Receptor; D018432:Drug Resistance, Multiple; D019008:Drug Resistance, Neoplasm; D015870:Gene Expression / Q000187:drug effects*; D006801:Humans; D000068877:Imatinib Mesylate; D026901:Membrane Transport Proteins; D000089762:Multidrug Resistance-Associated Protein 2; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000096:biosynthesis* / Q000235:genetics; D009363:Neoplasm Proteins / Q000096:biosynthesis* / Q000235:genetics; D009369:Neoplasms / Q000235:genetics / Q000378:metabolism; D010879:Piperazines / Q000008:administration & dosage*; D000077297:Pregnane X Receptor; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors; D011743:Pyrimidines / Q000008:administration & dosage*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics / Q000378:metabolism; D011987:Receptors, Steroid / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D015533:Transcriptional Activation; D014407:Tumor Cells, Cultured
chemical_list: D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters; D000970:Antineoplastic Agents; D001549:Benzamides; D000090702:Constitutive Androstane Receptor; D000068877:Imatinib Mesylate; D026901:Membrane Transport Proteins; D000089762:Multidrug Resistance-Associated Protein 2; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D009363:Neoplasm Proteins; D010879:Piperazines; D000077297:Pregnane X Receptor; D011505:Protein-Tyrosine Kinases; D011743:Pyrimidines; D012333:RNA, Messenger; D018160:Receptors, Cytoplasmic and Nuclear; D011987:Receptors, Steroid; D014157:Transcription Factors; C000715087:ABCC2 protein, human; C116614:ABCG2 protein, human; C000625852:NR1I2 protein, human; C421109:multidrug resistance-associated protein 1