Induction of CYP3As in HepG2 Cells by Several Drugs. Association between Induction of CYP3A4 and Expression of Glucocorticoid Receptor.

Usui, Tatsuhiro; Saitoh, Yurika; Komada, Fusao

doi:10.1248/bpb.26.510

Cited by 56 publications

(30 citation statements)

References 49 publications

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“…5). These results were consistent with those reported previously by Sumida et al 25) and Usui et al 35) Hewitt and Hewitt 36) reported that HepG2 cells have phase I enzymes, i.e., CYP1A, CYP2C9, CYP2D6, CYP2B6, CYP2E1, and CYP3A, but their activities and levels are dependent on the source and culture conditions. This discrepancy may have been due to differences in source and/or culture conditions.…”

Section: Expression Of Pxr and Gra A In Hepg2 And Hfl Cells Rt-pcr Wasupporting

confidence: 93%

Comparison of Basal Gene Expression and Induction of CYP3As in HepG2 and Human Fetal Liver Cells

Maruyama

Matsunaga

Harada

et al. 2007

Biological & Pharmaceutical Bulletin

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Cytochrome P450 (CYP) is a gene superfamily of hemoproteins that catalyze the oxidation of lipophilic substrates to more water-soluble products. Among them, the human CYP3A subfamily contains mainly three isoforms, CYP3A4, CYP3A5, and CYP3A7. 1) CYP3A4 is the predominant isoform expressed in adult human liver and intestine, 2,3) and plays a significant role in the metabolism of endogenous and exogenous compounds. 4) CYP3A5 is expressed polymorphically throughout development in the liver.5,6) CYP3A7 is a major CYP isoform in the human fetal and newborn liver. 7)The levels of expression of CYP3A isoforms are enhanced by treatment with various agents, such as rifampicin (RIF), phenobarbital, clotrimazole, and dexamethasone (DEX). [8][9][10] Unlike the fetal liver in most experimental animals, the human fetus supports the oxidative metabolism of a wide range of drugs and other xenobiotics. 11) Toxicological and pharmacological studies designed to assess the safety and efficacy of candidate drugs and chemicals in the human fetus depend greatly on extrapolation from animal models. However, it has been difficult to estimate alterations of drug metabolism by inducers of drug-metabolizing enzymes in the human fetus due to the problem of differences among species.12) Species differences in the inducibility of drug-metabolizing enzymes 13,14) result in important differences in the metabolism of drugs and potential carcinogens. The induction of CYP3A in human-derived cell lines has been studied as a model of human tissues.15) As research with human subjects, especially when pregnant, should be restricted due to ethical considerations, human fetal in vitro models have been evaluated with increasing frequency to find those that are most suitable for predicting human responses in vivo.The HepG2 cell line was established from a liver tumor biopsy specimen from a 15-year-old Caucasian male subject.16) This cell line has features of hepatoblast-like cells, because the cells express CYP3A7 17) and secrete a-fetoprotein (AFP) 16) into the cell culture medium, both proteins that are found predominantly in human fetal hepatocytes.7) However, it is unknown whether HepG2 is a useful cell line as a human fetal liver (HFL) model for experiments regarding drug metabolism, because there have been no comparisons of gene expression between HFL and HepG2 cells, and limited data are available regarding comparison of the responses of HepG2 and HFL cells to inducers.In the present study, to characterize the expression and induction of CYP in HFL cells, the basal gene expression patterns and inducibility of CYP, especially CYP3A isoforms, were compared to those in HepG2 cells. MATERIALS AND METHODS ChemicalsDulbecco's phosphate-buffered saline (PBS) was from Dainippon Pharmaceutical Co. (Osaka, Japan). Dulbecco's modified Eagle's medium and Williams' medium E were purchased from Sigma Chemical Co. (St. Louis, MO, U.S.A.). Penicillin-streptomycin-neomycin antibiotic mixture and SuperScript First-Strand Synthesis System for reverse transcription-po...

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Section: Expression Of Pxr and Gra A In Hepg2 And Hfl Cells Rt-pcr Wasupporting

confidence: 93%

Comparison of Basal Gene Expression and Induction of CYP3As in HepG2 and Human Fetal Liver Cells

Maruyama

Matsunaga

Harada

et al. 2007

Biological & Pharmaceutical Bulletin

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“…Exposure of primary hepatocytes to phenobarbital resulted in large increases in CYP3A4 expression levels (maximal 1200% of control; Fig. 4D), as previously reported (Raucy, 2003;Usui et al, 2003), with more modest changes in CYP3A5 and CYP3A43 (maximal 347% and 286% of control, respectively).…”

Section: Chromatin Conformation Regulates Human Cyp3a Expressionsupporting

confidence: 85%

“…Despite this, primary hepatocytes have been extensively used to study xenobiotic effects on DMEs, particularly at the level of the transcriptome (Raucy, 2003). By comparison, whereas hepatoma cell lines are capable of supporting xenobiotic-mediated transcription based upon nonchromosomal reporter genes (El-Sankary et al, 2001), evidence for genomic-based transcription is more equivocal (Krusekopf et al, 2003;Raucy, 2003;Usui et al, 2003).…”

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confidence: 99%

Impact of Transcription Factor Profile and Chromatin Conformation on Human Hepatocyte Cyp3a Gene Expression

Phillips

Hood²,

Gibson³

et al. 2004

Drug Metab Dispos

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ABSTRACT:Recent data have made it increasingly clear that the gene expression profile of a cell system, and its alteration in response to external stimuli, is highly dependent on both the higher order chromatin structure of the genome and the interaction of gene products in interpreting stimuli. To further explore this phenomenon, we have examined the role of both of these factors in controlling xenobiotic-mediated gene expression changes in primary and transformed human hepatocytes (HuH7). Using quantitative polymerase chain reaction, expression levels of several transcription factors implicated in the liver-specific regulation of the CYP3A gene family were examined in human adult and fetal liver RNA samples. These expression profiles were then compared with those obtained from both primary and transformed human hepatocytes, showing that, in general, cultured cells exhibit a distinct profile compared with either the fetal or adult samples. Transcriptome profiles before and after exposure to the CYP3A transcriptional activators rifampicin, dexamethasone, pregnane-16␣-carbonitrile, and phenobarbital were subsequently examined. Whereas exposure to these compounds elicited a dose-dependent increase in CYP3A transcription in primary hepatocytes, no alteration in expression levels was observed for the hepatoma cell line HuH7. Alteration in the expression levels of pregnane X receptor and chicken ovalbumin upstream promoter transcription factor I, and the disruption of higher order chromatin within HuH7 cells altered CYP3A expression and/or activation by xenobiotics toward that observed in primary hepatocytes. These data provide potential roles for these two processes in regulating CYP3A expression in vivo.

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“…This is consistent with the mRNA analysis data, which also show no CYP3A induction after treatment with the same compounds. Furthermore, as mentioned before, HepG2 expresses CYP3A7, which is not induced by rifampicin (Krusekopf et al, 2003;Usui et al, 2003). Krusekopf only observed pronounced CYP3A7 induction in HepG2 after treatment with typical human glucocorticoid receptor agonists indicating an important role for the human glucocorticoid receptor in CYP3A7 regulation.…”

Section: Discussionsupporting

confidence: 51%

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

Harmsen¹,

Koster²,

Beijnen³

et al. 2008

Drug Metab Dispos

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ABSTRACT: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.

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Induction of CYP3As in HepG2 Cells by Several Drugs. Association between Induction of CYP3A4 and Expression of Glucocorticoid Receptor.

Cited by 56 publications

References 49 publications

Comparison of Basal Gene Expression and Induction of CYP3As in HepG2 and Human Fetal Liver Cells

Comparison of Basal Gene Expression and Induction of CYP3As in HepG2 and Human Fetal Liver Cells

Impact of Transcription Factor Profile and Chromatin Conformation on Human Hepatocyte Cyp3a Gene Expression

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

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