AR42J-B-13 (B-13) cells form hepatocyte-like (B-13/H) cells in response to
glucocorticoid treatment. To establish its utility in toxicity and genotoxicity screening,
cytochrome P450 (CYP) induction, susceptibility to toxins, and transporter gene expression were examined. Conversion to B-13/H cells resulted in expression of male-specific CYP2C11 and sensitivity to
methapyrilene. B-13/H cells constitutively expressed CYP1A, induced expression in response to an
aryl hydrocarbon receptor agonist, and activated benzo[α]
pyrene to
a DNA-damaging species. Functional
CYP1A2 was not expressed due to deletions in the
Cyp1a2 gene. A B-13 cell line stably expressing the human
CYP1A2 was therefore engineered (B-13(-TR/h1A2)) and the derived B-13/H cells expressed metabolically functional
CYP1A2. Treatment with the cooked food
mutagen 2-amino-1-methyl-6-phenylimidazo(4,5-b)pyridine resulted in a dose-dependent increase in DNA damage. B-13/H cells expressed
constitutive androstane receptor (CAR) and induced
CYP2B1 mRNA levels in response to classical CAR activators. However, translation to functional
CYP2B1 protein was low and increased minimally by CAR activator treatment. B-13/H cells expressed high levels of
pregnane X-receptor (PXR) and induced CYP3A1 in response to classical PXR activators.
CYP3A genes were inducible, functional, and activated
aflatoxin B1 to
a DNA-damaging species. All 23 major hepatic transporters were induced when B-13 cells were converted to B-13/H cells, although in many cases, levels remained below those present in adult rat liver. However,
bile salt export pump, Abcb1b,
multidrug resistance-associated protein, and
breast cancer resistance
protein transporters were functional in B-13/H cells. These data demonstrate that the B-13 cell generates hepatocyte-like cells with functional
drug metabolism and transporter activities, which can alone--or in a humanized form--be used to screen for hepatotoxic and genotoxic endpoints in vitro.