Function and expression of multidrug resistance-associated protein family in human colon adenocarcinoma cells (Caco-2).

摘要: Several organic anions are actively extruded from intestinal epithelial cells into the lumen and vascular sides. To examine role of multidrug resistance-associated protein (MRP) family in efflux anions, function expression these proteins were investigated with Caco-2, a human adenocarcinoma cell line that retains many characteristics normal enterocytes. [3H]2,4-Dinitrophenyl- S -glutathione (DNP-SG) [3H]17β-estradiol 17-β-d-glucuronide (E217βG), typical substrates for MRP1 cMOAT (canalicular multispecific anion transporter)/MRP2, taken up brush-border membrane vesicles (BBMVs) Caco-2 an ATP-dependent manner, K m values 16.9 ± 7.2 9.4 1.2 μM, respectively. The uptake [3H]DNP-SG BBMVs was osmotically sensitive stimulated to some extent by other nucleotide triphosphates (GTP, CTP, UTP) but not ADP or AMP. An ATPase inhibitor, vanadate, inhibited extent. Reverse-transcriptase polymerase chain reaction resulted amplification MRP1, MRP3, MRP5. Northern blot analysis indicated extensive cMOAT/MRP2 MRP3 only minimal Although continuously expressed throughout culture period, immediately after confluent state reached. Collectively, presence transport systems DNP-SG E217βG demonstrated cells. Because may be on basolateral membranes cells, respectively, activity associated result cMOAT/MRP2.