title: Molecular and functional characterization of drug-metabolizing enzymes and transporter expression in the novel spontaneously immortalized human hepatocyte line HC-04.
abstract: In toxicological research, immortalized human hepatocytes provide a useful alternative to primary hepatocytes because interindividual variability in the expression of drug-metabolizing enzymes and drug transporters can largely be eliminated. However, it is essential that the cell line retain the original phenotype. The purpose of this study was to characterize a novel spontaneously immortalized human hepatocyte cell line, HC-04, with respect to the transcript and functional protein expression profile for the major drug-metabolizing enzymes and transmembrane transporters. HC-04 cells retained hepatocyte-specific function including albumin production and ornithine transcarbamoylase and glucose-6-phosphatase activity. Most of the major CYP forms were expressed at basal levels and responsive to inducing agents. In particular, CYP3A4 was expressed abundantly, and HC-04 cells were able to metabolize the CYP3A4 probe, midazolam, at a rate similar to primary human hepatocytes. Furthermore, the major human sulfotransferase and UDP-glucuronosyltransferase forms, as well as members of the ABC and SLC transporter superfamilies, nuclear receptors, and hepatic transcription factors were also expressed. HC-04 cells readily responded to standard hepatotoxicants that are dependent on CYP-mediated bioactivation, while another, tumor-derived cell line remained refractory to the drug challenge. Collectively, HC-04 cells provide a reliable, stable, and reproducible model for biomechanistic studies in drug toxicology.
authors.affiliation: Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore.
authors.forename: Priscilla L K
authors.initials: PL
authors.lastname: Lim
authors.forename: Weiqi
authors.initials: W
authors.lastname: Tan
authors.forename: Calivarathan
authors.initials: C
authors.lastname: Latchoumycandane
authors.forename: Wei Chuen
authors.initials: WC
authors.lastname: Mok
authors.forename: Yok Moi
authors.initials: YM
authors.lastname: Khoo
authors.forename: How Sung
authors.initials: HS
authors.lastname: Lee
authors.forename: Jetsumon
authors.initials: J
authors.lastname: Sattabongkot
authors.forename: Walter
authors.initials: W
authors.lastname: Beerheide
authors.forename: Seng Gee
authors.initials: SG
authors.lastname: Lim
authors.forename: Theresa M C
authors.initials: TM
authors.lastname: Tan
authors.forename: Urs A
authors.initials: UA
authors.lastname: Boelsterli
mesh_terms: D000082:Acetaminophen / Q000378:metabolism; D018712:Analgesics, Non-Narcotic / Q000378:metabolism; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000378:metabolism; D000933:Antifibrinolytic Agents / Q000378:metabolism; D015415:Biomarkers; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism*; D004008:Diclofenac / Q000378:metabolism; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D022781:Hepatocytes / Q000378:metabolism*; D006801:Humans; D024483:Vitamin K 3 / Q000378:metabolism
chemical_list: D018712:Analgesics, Non-Narcotic; D000894:Anti-Inflammatory Agents, Non-Steroidal; D000933:Antifibrinolytic Agents; D015415:Biomarkers; D002352:Carrier Proteins; D004008:Diclofenac; D000082:Acetaminophen; D024483:Vitamin K 3; D003577:Cytochrome P-450 Enzyme System