title: HepG2 cells simultaneously expressing five P450 enzymes for the screening of hepatotoxicity: identification of bioactivable drugs and the potential mechanism of toxicity involved.
abstract: Use of the HepG2 cell line to assess hepatotoxicity induced by bioactivable compounds is hampered by their low cytochrome P450 expression. To overcome this limitation, we have used adenoviral transfection to develop upgraded HepG2 cells (ADV-HepG2) expressing the major P450 enzymes involved in drug metabolism (CYP1A2, CYP2D6, CYP2C9, CYP2C19, and CYP3A4) at levels comparable to those of human hepatocytes. The potential utility of this new cell model for the in vitro screening of bioactivable drugs was assessed using a high-content screening assay that we recently developed to simultaneously measure multiple parameters indicative of cell injury. To this end, ADV-HepG2 and HepG2 cells, cultured in 96-well plates, were exposed for 24 h to a wide range of concentrations of 12 bioactivable and 3 non-bioactivable compounds. The cell viability and parameters associated with nuclear morphology, mitochondrial function, intracellular calcium concentration, and oxidative stress indicative of prelethal cytotoxicity and representative of different mechanisms of toxicity were evaluated. Bioactivable compounds showed lower IC(50) values in ADV-HepG2 cells than in HepG2 cells. Moreover, significant differences in the other parameters analyzed were observed between both cell models, while similar effects were observed for non-bioactivable compounds (negative controls). The changes in cell parameters detected in our assay for a given compound are in good agreement with the previously reported toxicity mechanism. Overall, our results indicate that this assay may be a suitable new in vitro approach for early screening of compounds to identify bioactivable hepatotoxins and the mechanism(s) involved in their toxicity.
authors: Unidad de Hepatología Experimental, Centro de Investigación, Instituto de Investigación Sanitaria Hospital La Fe, Valencia, Avda de Campanar 21, 46009 Valencia, Spain. laiatolosa@hotmail.com
authors: Laia
authors: L
authors: Tolosa
authors: M José
authors: MJ
authors: Gómez-Lechón
authors: Gabriela
authors: G
authors: Pérez-Cataldo
authors: José V
authors: JV
authors: Castell
authors: M Teresa
authors: MT
authors: Donato
mesh_terms: D000256:Adenoviridae / Q000235:genetics; D001682:Biological Availability; D002118:Calcium / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D003577:Cytochrome P-450 Enzyme System / Q000096:biosynthesis* / Q000235:genetics; D004305:Dose-Response Relationship, Drug; D004790:Enzyme Induction; D005822:Genetic Vectors; D056945:Hep G2 Cells; D057166:High-Throughput Screening Assays; D006801:Humans; D020128:Inhibitory Concentration 50; D007527:Isoenzymes; D008113:Liver Neoplasms / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D008930:Mitochondria, Liver / Q000187:drug effects / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects; D004364:Pharmaceutical Preparations / Q000378:metabolism*; D018570:Risk Assessment; D013379:Substrate Specificity; D013997:Time Factors; D018675:Toxicity Tests / Q000379:methods*; D014162:Transfection
chemical_list: D007527:Isoenzymes; D004364:Pharmaceutical Preparations; D003577:Cytochrome P-450 Enzyme System; D002118:Calcium