title: Increased expression of drug-metabolizing enzymes in human hepatocarcinoma FLC-4 cells cultured on micro-space cell culture plates.
abstract: Human hepatocellular carcinoma cell lines cultured in a monolayer show negligible activities of drug-metabolizing enzymes such as cytochrome P450s (CYPs) and UDP-glucuronosyltransferases (UGTs). Here, we show that culture of human hepatocellular carcinoma FLC-4 cells on 24-well plates arrayed with uniform micro-sized compartments on the bottom of the plates (micro-space cell culture plates) resulted in increased expression of drug-metabolizing enzymes (CYP1A2, CYP2C9, CYP3A4, UGT1A1, etc.) and nuclear receptors (pregnane X receptor, constitutive androstane receptor, etc.). When cells were treated with a typical CYP3A substrate (triazolam), CYP2C9 substrate (diclofenac) or UGT1A1 substrate (SN-38), large amounts of their metabolites were detected in the medium of cells cultured on micro-space cell culture plates. The formation of metabolites from triazolam, diclofenac and SN-38 was strongly inhibited by co-treatment with a CYP3A inhibitor (ketoconazole), CYP2C9 inhibitor (sulfaphenazole) and UGT1A1 inhibitor (ketoconazole), respectively. On the other hand, formation of metabolites was not observed in the medium of cells cultured in a monolayer. Finally, the cytotoxic effect of aflatoxin B1 was more potent in cells cultured on micro-space cell culture plates than in cells cultured in a monolayer. The results suggest that FLC-4 cells cultured on micro-space cell culture plates are useful for studying drug metabolism and drug-induced hepatotoxicity.
authors.affiliation: Laboratory of Pharmacology and Toxicology, Graduate School of Pharmaceutical Sciences, Chiba University, Chiba, Japan. kaoruk@faculty.chiba-u.jp
authors.forename: Kaoru
authors.initials: K
authors.lastname: Kobayashi
authors.forename: Akane
authors.initials: A
authors.lastname: Yoshida
authors.forename: Yoko
authors.initials: Y
authors.lastname: Ejiri
authors.forename: Sachiko
authors.initials: S
authors.lastname: Takagi
authors.forename: Hanaka
authors.initials: H
authors.lastname: Mimura
authors.forename: Masaya
authors.initials: M
authors.lastname: Hosoda
authors.forename: Tomokazu
authors.initials: T
authors.lastname: Matsuura
authors.forename: Kan
authors.initials: K
authors.lastname: Chiba
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D018929:Cell Culture Techniques; D045744:Cell Line, Tumor; D000090702:Constitutive Androstane Receptor; D003577:Cytochrome P-450 Enzyme System / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D014453:Glucuronosyltransferase / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008658:Inactivation, Metabolic; D007527:Isoenzymes; D008099:Liver / Q000201:enzymology / Q000378:metabolism / Q000473:pathology; D008113:Liver Neoplasms / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D000077297:Pregnane X Receptor; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics / Q000378:metabolism; D011987:Receptors, Steroid / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D000099148:UGT1A1 Enzyme
chemical_list: D000090702:Constitutive Androstane Receptor; D003577:Cytochrome P-450 Enzyme System; D014453:Glucuronosyltransferase; D007527:Isoenzymes; D000077297:Pregnane X Receptor; D012333:RNA, Messenger; D018160:Receptors, Cytoplasmic and Nuclear; D011987:Receptors, Steroid; D014157:Transcription Factors; D000099148:UGT1A1 Enzyme