Differential susceptibility of mice humanized for peroxisome proliferator-activated receptor alpha to Wy-14,643-induced liver tumorigenesis

Morimura, K; Cheung, C; Ward, JM; Reddy, JK; Gonzalez, FJ

HERO ID

716637

Reference Type

Journal Article

Year

2006

Language

English

PMID

16377806

HERO ID 716637
In Press No
Year 2006
Title Differential susceptibility of mice humanized for peroxisome proliferator-activated receptor alpha to Wy-14,643-induced liver tumorigenesis
Authors Morimura, K; Cheung, C; Ward, JM; Reddy, JK; Gonzalez, FJ
Journal Carcinogenesis
Volume 27
Issue 5
Page Numbers 1074-1080
Abstract Peroxisome proliferators, such as lipid-lowering fibrate drugs, are agonists for the peroxisome proliferator-activated receptor alpha (PPARalpha). Sustained activation of PPARalpha leads to the development of liver tumors in rodents. Paradoxically, humans appear to be resistant to the induction of peroxisome proliferation and development of liver tumors by peroxisome proliferators. To examine the species differences in response to peroxisome proliferators, a PPARalpha humanized mouse (hPPARalpha) was generated, in which the human PPARalpha was expressed in liver under control of the Tet-OFF system. To evaluate the susceptibility of hPPARalpha mice to peroxisome proliferator-induced hepatocarcinogenesis, a long-term feeding study of Wy-14,643 was carried out. hPPARalpha and wild-type (mPPARalpha) mice were fed either a control diet or one containing 0.1% Wy-14,643 for 44 and 38 weeks, respectively. Gene expression analysis for peroxisomal and mitochondrial fatty acid metabolizing enzymes revealed that both hPPARalpha and mPPARalpha were functional. However, the incidence of liver tumors including hepatocellular carcinoma was 71% in Wy-14,643-treated mPPARalpha mice, and 5% in Wy-14,643-treated hPPARalpha mice. Upregulation of cell cycle regulated genes such as cd1 and Cdks were observed in non-tumorous liver tissue of Wy-14,643-treated mPPARalpha mice, whereas p53 gene expression was increased only in the livers of Wy-14,643-treated hPPARalpha mice. These findings suggest that structural differences between human and mouse PPARalpha are responsible for the differential susceptibility to the peroxisome proliferator-induced hepatocarcinogenesis. This mouse model will be useful for human cancer risk assessment of PPARalpha ligands.
Doi 10.1093/carcin/bgi329
Pmid 16377806
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Dupe Override No
Is Public Yes
Language Text English
Is Qa No