The selection was made taking into account the relevance of the target organ and the nature of the test article. The human lung-derived BEAS-2B cell line was first described in 1988, when normal bronchial epithelial cells obtained from autopsy of non-cancerous individuals were isolated, then infected with a replication-defective 12-SV40/adenovirus hybrid and cloned to create an immortalized phenotype (Reddel et al., 1988). The non-cancerous phenotype of BEAS-2B

cells is an advantage Atezolizumab chemical structure in the investigation of carcinogenic processes such as DNA damage and cell transformation (Sun et al., 2011). Therefore, BEAS-2B cells have been considered as a relevant cell line for in vitro toxicology testing in the field of pollutants, tobacco products and nanomaterials ( Persoz et al., 2012, Veljkovic et al., 2011 and Haniu et al., 2011). Although, several studies have employed BEAS-2B cells to evaluate the effect of some pro-toxicants such as B[a]P and 4-(N-methylnitrosamino)-1-(3-pyridinyl)-1-butanone (NNK), the metabolic capacity of this particular cell line has not been fully

characterized ( Ovrevik et al., 2010 and Proulx BTK inhibitor et al., 2005). Here, BEAS-2B cells were tested and compared to the lung-derived A549 cells broadly used as pulmonary in vitro system but with no cytochrome P450 expression reported for CYP1A2 and the CYP2A family, and inducibility documented for CYP1A1/1B1 genes ( Hukkanen et al., 2002 and Castell et al., 2005). acetylcholine Cells derived from hepatocarcinomas considered

to have a more extensive cytochrome P450 enzyme activity (HepG2 and HepaRG) were used as a more comprehensive control for our CYP assays ( Jennen et al., 2010). Moreover, the results were contrasted to those reported in primary human bronchial epithelium culture ( Newland et al., 2011 and Courcot et al., 2012). The results of this study are considered to be useful for in vitro toxicological testing using the cell line BEAS-2B as cell system. Furthermore, we propose that the outlined strategy can be incorporated in the characterization of cell systems used in in vitro testing. The human bronchial epithelial cell line (BEAS-2B), purchased from ATCC (United States), was seeded into culture vessels that had been pre-coated with 0.03 mg/mL PureCol® bovine collagen solution (Nutacon, The Netherlands). Cells were maintained in Bronchial Epithelial Growth Medium (BEGM®) at 37 °C and 5% CO2 in a humidified incubator. BEGM® was prepared by supplementing Bronchial Epithelial Basal Medium with growth supplements provided in the manufacturer’s BEGM® SingleQuot® kit (Lonza Group Ltd., Belgium) containing: bovine pituitary extract, hydrocortisone, human epidermal growth factor, epinephrine, insulin, triiodothyronine, transferrin, gentamicin/amphotericin-B and retinoic acid.