ESTABLISHMENT AND CHARACTERIZATION OF A KIDNEY-DRUG INTERACTION MODEL BY STABLY EXPRESSING hOAT1 IN HEK 293T/17 CELLS

INTRODUCTION In vivo studies have shown that kidney membrane transporters play a key part in drug disposition and renal clearance. One such transporter is OAT1 (SLC22A6), which is critical for maintaining homeostasis of endogenous substances. This makes OAT1 a good transporter to assay for drug interactions with the kidney. Unfortunately, primary cells lose OAT1 expression in culture, and transiently expressed OAT1 has great variations between production lots, which makes data hard to interpret. In our study, we generated HEK 293T/17 cells that stably overexpress the OAT1 gene driven by the human elongation factor-1 alpha (EF1α) promoter. We validated that the overexpressed OAT1 transporter has normal transport activities by using 5-carboxyfluorescein (5-CF) and para-aminohipurate (PAH; data not shown) uptake assays, and that the uptake can be inhibited by the well-known inhibitors probenecid and novobiocin. Overall, our data has shown that this modified cell line is a very useful in vitro tool for testing regulation of OAT1 membrane transporter activity in kidney cells.