title: Dose- and time-dependent effects of phenobarbital on gene expression profiling in human hepatoma HepaRG cells.
abstract: Phenobarbital (PB) induces or represses a wide spectrum of genes in rodent liver. Much less is known about its effects in human liver. We used pangenomic cDNA microarrays to analyze concentration- and time-dependent gene expression profile changes induced by PB in the well-differentiated human HepaRG cell line. Changes in gene expression profiles clustered at specific concentration ranges and treatment times. The number of correctly annotated genes significantly modulated by at least three different PB concentration ranges (spanning 0.5 to 3.2 mM) at 20 h exposure amounted to 77 and 128 genes (p< or =0.01) at 2- and 1.8-fold filter changes, respectively. At low concentrations (0.5 and 1 mM), PB-responsive genes included the well-recognized CAR- and PXR-dependent responsive cytochromes P450 (CYP2B6, CYP3A4), sulfotransferase 2A1 and plasma transporters (ABCB1, ABCC2), as well as a number of genes critically involved in various metabolic pathways, including lipid (CYP4A11, CYP4F3), vitamin D (CYP24A1) and bile (CYP7A1 and CYP8B1) metabolism. At concentrations of 3.2 mM or higher after 20 h, and especially 48 h, increased cytotoxic effects were associated with disregulation of numerous genes related to oxidative stress, DNA repair and apoptosis. Primary human hepatocyte cultures were also exposed to 1 and 3.2 mM PB for 20 h and the changes were comparable to those found in HepaRG cells treated under the same conditions. Taken altogether, our data provide further evidence that HepaRG cells closely resemble primary human hepatocytes and provide new information on the effects of PB in human liver. These data also emphasize the importance of investigating dose- and time-dependent effects of chemicals when using toxicogenomic approaches.
authors.affiliation: INSERM U620 and Université de Rennes 1, 35043 Rennes, France.
authors.forename: Carine B
authors.initials: CB
authors.lastname: Lambert
authors.forename: Catherine
authors.initials: C
authors.lastname: Spire
authors.forename: Nancy
authors.initials: N
authors.lastname: Claude
authors.forename: Andre
authors.initials: A
authors.lastname: Guillouzo
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D006528:Carcinoma, Hepatocellular / Q000201:enzymology / Q000235:genetics*; D045744:Cell Line, Tumor; D016000:Cluster Analysis; D003577:Cytochrome P-450 Enzyme System / Q000187:drug effects / Q000235:genetics; D004305:Dose-Response Relationship, Drug; D020869:Gene Expression Profiling / Q000379:methods; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D022781:Hepatocytes / Q000187:drug effects* / Q000201:enzymology; D006801:Humans; D008113:Liver Neoplasms / Q000201:enzymology / Q000235:genetics*; D000089762:Multidrug Resistance-Associated Protein 2; D020411:Oligonucleotide Array Sequence Analysis; D010634:Phenobarbital / Q000494:pharmacology* / Q000633:toxicity; D025341:Principal Component Analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors
chemical_list: C000715087:ABCC2 protein, human; D000089762:Multidrug Resistance-Associated Protein 2; D000255:Adenosine Triphosphate; D003577:Cytochrome P-450 Enzyme System; D010634:Phenobarbital