Comparison of Two Immortalized Human Cell Lines to Study Nuclear Receptor-Mediated CYP3A4 Induction

• Published in: Drug metabolism and disposition Vol. 36; no. 6; pp. 1166 - 1171
• Main Authors: HARMSEN, S, KOSTER, A. S, BEIJNEN, J. H, SCHELLENS, J. H. M, MEIJERMAN, I
• Format: Journal Article
• Language: English
• Published: Bethesda, MD American Society for Pharmacology and Experimental Therapeutics 01-06-2008
• Subjects: Biological and medical sciences; Cell Line, Tumor - enzymology; Cytochrome P-450 CYP3A - biosynthesis; Cytochrome P-450 CYP3A - genetics; Enzyme Induction; Genes, Reporter - genetics; Humans; Medical sciences; Pharmacology. Drug treatments; Receptors, Cytoplasmic and Nuclear - agonists; Receptors, Cytoplasmic and Nuclear - metabolism; RNA, Messenger - metabolism; Human; Nuclear receptor; Cell line; Enzyme; Induction; Isozyme; Cytochrome P450; Established cell line; Cell immortalization; In vitro; Comparative study
• ISSN: 0090-9556; 1521-009X
• DOI: 10.1124/dmd.107.017335

Since CYP3A4 is responsible for the biotransformation of over 50% of all clinically used drugs, induction results in an increased
clearance of many concomitantly administered drugs, thereby decreasing treatment efficacy or, in the case of prodrugs, lead
to severe intoxications. CYP3A4 induction is regulated by the pregnane X receptor, constitutive androstane receptor, and vitamin
D receptor. Since these nuclear receptors show large interspecies differences, accurate prediction of nuclear receptor-mediated
CYP3A4 induction in humans requires the use of human systems. Because primary cultures of human hepatocytes or enterocytes
have major drawbacks like poor availability and poor reproducibility, human cell lines are a good alternative. In this study,
the widely used HepG2 cell line was compared with the LS180 cell line to serve as a model to study CYP3A4 induction. There
was a clear difference between the cell lines with respect to CYP3A enzyme expression and induction. In LS180, CYP3A4 was
expressed and was found to be induced by prototypical nuclear receptor agonists, whereas in HepG2, CYP3A4 was nonresponsive
to treatment with rifampicin, CITCO [6-(4-chlorophenyl)imidazo[2,1- b ][1,3]thiazole-5-carbaldehyde- O -3,4-dichlorobenzyl) oxime], or calcitriol. We subsequently evaluated whether these host-cell differences also have an effect
on CYP3A4 reporter gene activity. We clearly show that there are differences in CYP3A4 reporter activity between the cell
lines, and based on these results and those found on mRNA and protein level, we conclude that LS180 is a more suitable cell
line to study CYP3A4 induction than the widely used HepG2.