Background: Cell culture techniques have many advantages for investigation of drug transport to target organ like liver. HepG2 and Huh-7 are two cell lines available from hepatoma that can be used as a model for hepatic drug transport. The present study is aimed to analyze the expression level of several drug transporter genes in two hepatoma cell lines, HepG2 and Huh-7 and their response to inhibitors.
Materials and Methods: This is an in vitro study using HepG2 and Huh-7 cells. The expression level of the following drug transporter genes was quantified: P-glycoprotein/multidrug resistance protein 1, Organic Anionic Transporter Protein 1B1 (OATP1B1) and Organic Cationic Transporter-1 (OCT1). Ribonucleic acid was extracted from the cells using Tripure isolation reagent, then gene expression level of the transporters is quantified using Applied Biosystems quantitative reverse transcriptase polymerase chain reaction. Verapamil (P-glycoprotein inhibitor), nelfinavir (OATP1B1 inhibitor), quinidine (OCT1 inhibitor) were used to differentiate the inhibitory properties of these agents to the transporter expressions in HepG2 and Huh-7 cells.
Results: Huh-7 shows a higher level of P-glycoprotein, OATP1B1 and OCT1 expressions compared with those of HepG2. Verapamil reduces the expressions of P-glycoprotein in HepG2 and Huh-7; nelfinavir reduces the expression of OATP1B1 in HepG2 and Huh-7; while quinidine reduces the OCT1 gene expressions in HepG2, but not in Huh-7 cells.
Conclusion: This study indicates that HepG2 might be a more suitable in vitro model than Huh-7 to study drug transport in hepatocytes involving drug transporters.
Gerets HH, Tilmant K, Gerin B, Chanteux H, Depelchin BO, Dhalluin S, et al. Characterization of primary human hepatocytes, HepG2 cells, and HepaRG cells at the mRNA level and CYP activity in response to inducers and their predictivity for the detection of human hepatotoxins. Cell Biol Toxicol 2012;28:69-87.
Brandon EF, Bosch TM, Deenen MJ, Levink R, van der Wal E, van Meerveld JB, et al. Validation of in vitro cell models used in drug metabolism and transport studies; genotyping of cytochrome P450, phase II enzymes and drug transporter polymorphisms in the human hepatoma (HepG2), ovarian carcinoma (IGROV-1) and colon carcinoma (CaCo-2, LS180) cell lines. Toxicol Appl Pharmacol 2006;211:1-10.
Minematsu T, Iwai M, Umehara K-I, Usui T, Kamimura H. Characterization of human organic cation transporter 1 (OCT1/SLC22A1)- and OCT2 (SLC22A2) -mediated transport of 1-(2-methoxyethyl)-2-methyl-4,9-dioxo-3-(pyrazin-2-ylmethyl)- 4,9 -dihydro-1H-naphtho[2,3-d] imidazolium bromide (YM155 monobromide), a novel small molecule survivin suppressant. Drug Metab Dispos 2010;38:1-4.
Taipalensuu J, Törnblom H, Lindberg G, Einarsson C, Sjöqvist F, Melhus H, et al. Correlation of gene expression of ten drug efflux proteins of the ATP-binding cassette transporter family in normal human jejunum and in human intestinal epithelial Caco-2 cell monolayers. J Pharmacol Exp Ther 2001;299:164-70.