title: HepaRG human hepatic cell line utility as a surrogate for primary human hepatocytes in drug metabolism assessment in vitro.
abstract: BACKGROUND
  Primary human hepatocytes are considered as a highly predictive in vitro model for preclinical drug metabolism studies. Due to the limited availability of human liver tissue for cell isolation, there is a need of alternative cell sources for pharmaceutical research.
  
  
  METHODS
  In this study, the metabolic activity and long-term stability of the human hepatoma cell line HepaRG were investigated in comparison to primary human hepatocytes (pHH). Hepatocyte-specific parameters (albumin and urea synthesis, galactose and sorbitol elimination) and the activity of human-relevant cytochrome P450 (CYP) enzymes (CYP1A2, CYP2C9, CYP2C19, CYP2D6 and CYP3A4) were assayed in both groups over a period of 14 days subsequently to a two week culture period in differentiated state in case of the HepaRG cells, and compared with those of cryopreserved hepatocytes in suspension. In addition, the inducibility of CYP enzymes and the intrinsic clearances of eleven reference drugs were determined.
  
  
  RESULTS
  The results show overall stable metabolic activity of HepaRG cells over the monitored time period. Higher albumin production and galactose/sorbitol elimination rates were observed compared with pHH, while urea production was not detected. CYP enzyme-dependent drug metabolic capacities were shown to be stable over the cultivation time in HepaRG cells and were comparable or even higher (CYP2C9, CYP2D6, CYP3A4) than in pHH, whereas commercially available hepatocytes showed a different pattern The intrinsic clearance rates of reference drugs and enzyme induction of most CYP enzymes were similar in HepaRG cells and pHH. CYP1A2 activity was highly inducible in HepaRG by β-naphthoflavone.
  
  
  CONCLUSIONS
  In conclusion, the results from this study indicate that HepaRG cells could provide a suitable alternative to pHH in pharmaceutical research and development for metabolism studies such as CYP induction or sub-chronic to chronic hepatotoxicity studies.
authors.affiliation: Division of Experimental Surgery, Berlin Brandenburg Center for Regenerative Therapies (BCRT), Charité Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, D-13353 Berlin, Germany. marc.luebberstedt@charite.de
authors.forename: Marc
authors.initials: M
authors.lastname: Lübberstedt
authors.forename: Ursula
authors.initials: U
authors.lastname: Müller-Vieira
authors.forename: Manuela
authors.initials: M
authors.lastname: Mayer
authors.forename: Klaus M
authors.initials: KM
authors.lastname: Biemel
authors.forename: Fanny
authors.initials: F
authors.lastname: Knöspel
authors.forename: Daniel
authors.initials: D
authors.lastname: Knobeloch
authors.forename: Andreas K
authors.initials: AK
authors.lastname: Nüssler
authors.forename: Jörg C
authors.initials: JC
authors.lastname: Gerlach
authors.forename: Katrin
authors.initials: K
authors.lastname: Zeilinger
mesh_terms: D006528:Carcinoma, Hepatocellular; D018929:Cell Culture Techniques; D045744:Cell Line, Tumor; D019963:Clinical Chemistry Tests; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism*; D004790:Enzyme Induction; D005260:Female; D022781:Hepatocytes / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D008113:Liver Neoplasms; D008297:Male; D050217:Metabolic Detoxication, Phase II; D004364:Pharmaceutical Preparations / Q000378:metabolism*
chemical_list: D004364:Pharmaceutical Preparations; D003577:Cytochrome P-450 Enzyme System