title: Metabolic characterization of cell systems used in in vitro toxicology testing: lung cell system BEAS-2B as a working example.
abstract: The bioactivation of pro-toxicants is the biological process through which some chemicals are metabolized into reactive metabolites. Therefore, in vitro toxicological evaluation should ideally be conducted in cell systems retaining adequate metabolic competency and relevant to the route of exposure. The respiratory tract is the primary route of exposure to inhaled pro-toxicants and lung-derived BEAS-2B cell line has been considered as a potentially suitable model for in vitro toxicology testing. However, its metabolic activity has not been characterized. We performed a gene expression analysis for 41 metabolism-related genes and compared the profile with liver- and lung-derived cell lines (HepaRG, HepG2 and A549). To confirm that mRNA expression was associated with the corresponding enzyme activity, we used a series of metabolic substrates of CYPs (CYP1A1/1B1, CYP1A2, CYP2A6/2A13 and CYP2E1) known to bioactivate inhaled pro-toxicants. CYP activities were compared between BEAS-2B, HepaRG, HepG2, and A549 cells and published literature on primary bronchial epithelium cells (HBEC). We found that in contrast to HBEC, BEAS-2B and A549 have limited CYP activity which was in agreement with their CYP gene expression profile. Control cell lines such as HepG2 and HepaRG were metabolically active for the tested CYPs. We recommend that similar strategies can be used to select suitable cell systems in the context of pro-toxicant assessment.
authors.affiliation: British American Tobacco, Group Research and Development, Regents Park Road, Southampton, Hampshire SO15 8TL, United Kingdom. Carolina_Garcia-Canton@bat.com
authors.forename: Carolina
authors.initials: C
authors.lastname: Garcia-Canton
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Minet
authors.forename: Arturo
authors.initials: A
authors.lastname: Anadon
authors.forename: Clive
authors.initials: C
authors.lastname: Meredith
mesh_terms: D002460:Cell Line / Q000201:enzymology*; D045744:Cell Line, Tumor / Q000201:enzymology*; D002470:Cell Survival / Q000187:drug effects; D065607:Cytochrome P-450 Enzyme Inhibitors; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics* / Q000378:metabolism; D020869:Gene Expression Profiling; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D008168:Lung / Q000166:cytology; D000072317:Polychlorinated Dibenzodioxins / Q000633:toxicity; D016133:Polymerase Chain Reaction; D018675:Toxicity Tests
chemical_list: D065607:Cytochrome P-450 Enzyme Inhibitors; D000072317:Polychlorinated Dibenzodioxins; D003577:Cytochrome P-450 Enzyme System
keywords: A549 cells; BEAS-2B cells; Cytochrome P450; HepG2 cells; HepaRG cells; Pro-toxicant