Xenobiotic stress induces hepatomegaly and liver tumors via the nuclear receptor constitutive androstane receptor.

Abstract

The constitutive androstane receptor (CAR, NR1I3) is a central regulator of xenobiotic metabolism. CAR activation induces hepatic expression of detoxification enzymes and transporters and increases liver size. Here we show that CAR-mediated hepatomegaly is a transient, adaptive response to acute xenobiotic stress. In contrast, chronic CAR activation results in hepatocarcinogenesis. In both acute and chronic xenobiotic responses, hepatocyte DNA replication is increased and apoptosis is decreased. These effects are absent in CAR null mice, which are completely resistant to tumorigenic effects of chronic xenobiotic stress. In the acute response, direct up-regulation of Mdm2 expression by CAR contributes to both increased DNA replication and inhibition of p53-mediated apoptosis. These results demonstrate an essential role for CAR in regulating both liver homeostasis and tumorigenesis in response to xenobiotic stresses, and they also identify a specific molecular mechanism linking chronic environmental stress and tumor formation.

0100200300'06'07'08'09'10'11'12'13'14'15'16'17
Citations per Year

1,543 Citations

Semantic Scholar estimates that this publication has 1,543 citations based on the available data.

See our FAQ for additional information.

Cite this paper

@article{Huang2005XenobioticSI, title={Xenobiotic stress induces hepatomegaly and liver tumors via the nuclear receptor constitutive androstane receptor.}, author={Wendong Huang and Jun Zhang and Michele Washington and Jun Liu and John M. Parant and Guillermina Lozano and David D. Moore}, journal={Molecular endocrinology}, year={2005}, volume={19 6}, pages={1646-53} }