title: Expression and activity of the efflux transporters ABCB1, ABCC2 and ABCG2 in the human colorectal carcinoma cell line LS513.
abstract: The human colorectal carcinoma cell line LS513 exhibits epithelial morphology, adherent properties and can grow subcutaneously to form tumors in nude mice. Thus, it is a potential model for mouse xenograft efficacy studies. The present study characterized the expression and activity of P-gp, BCRP and MRP2 in LS513 cells. We investigated the expression of these ATP-binding cassette transporters by Western blot and their activity was also examined using cell culture inserts, where the LS513 cells were grown to confluence for 9 days. The transport of model substrates of P-gp (amprenavir, ritonavir and topotecan), BCRP (topotecan) and MRP2 (SN-38) was studied in the apical to basolateral (A-B) and basolateral to apical (B-A) directions. P-gp, BCRP and MRP2 could be detected by western blot. The LS513 cells exhibited markedly higher transport in the B-A direction than in the A-B direction for the probe substrates tested, with efflux ratios (ERs; B-A/A-B) of 10, 21, 40 and 50 for amprenavir, ritonavir, topotecan and SN38, respectively. The ER could be significantly reduced with the addition of inhibitors of P-gp (GF120918), BCRP (FTC), and MRP2 (MK571), confirming the activity of these transporters in the LS513 cells.
authors.affiliation: Drug Metabolism and Pharmacokinetics Department, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, United States. salphati.laurent@gene.com
authors.forename: Laurent
authors.initials: L
authors.lastname: Salphati
authors.forename: Emile G
authors.initials: EG
authors.lastname: Plise
authors.forename: Guangmin
authors.initials: G
authors.lastname: Li
mesh_terms: D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000235:genetics*; D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000235:genetics*; D000199:Actins / Q000096:biosynthesis; D000818:Animals; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000494:pharmacology; D015153:Blotting, Western; D045744:Cell Line, Tumor; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000378:metabolism*; D006801:Humans; D007202:Indicators and Reagents; D051379:Mice; D018613:Microscopy, Confocal; D000089762:Multidrug Resistance-Associated Protein 2; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000235:genetics*; D009363:Neoplasm Proteins / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000235:genetics*; D013050:Spectrometry, Fluorescence
chemical_list: D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters; D000199:Actins; D000970:Antineoplastic Agents; D007202:Indicators and Reagents; D000089762:Multidrug Resistance-Associated Protein 2; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D009363:Neoplasm Proteins; C513055:ABCB1 protein, human; C000715087:ABCC2 protein, human; C116614:ABCG2 protein, human