| First Author | Qu A | Year | 2014 |
| Journal | J Hepatol | Volume | 60 |
| Issue | 2 | Pages | 331-8 |
| PubMed ID | 24096051 | Mgi Jnum | J:316497 |
| Mgi Id | MGI:6837412 | Doi | 10.1016/j.jhep.2013.09.024 |
| Citation | Qu A, et al. (2014) Role of Myc in hepatocellular proliferation and hepatocarcinogenesis. J Hepatol 60(2):331-8 |
| abstractText | BACKGROUND & AIMS: Myc is involved in cell growth, proliferation, apoptosis, energy metabolism, and differentiation. Whether it is essential for hepatocellular proliferation and carcinogenesis is unclear due to a lack of an efficient hepatocyte-specific Myc disruption model. This study used a novel genetic model to investigate the involvement of Myc in hepatocellular proliferation and hepatocarcinogenesis in mice. METHODS: Temporal hepatocyte-specific Myc disruption was achieved by use of the tamoxifen-inducible Cre-ER(T2) recombinase system under control of the serum albumin promoter. Hepatocyte proliferation was assessed by administering peroxisome proliferator-activated receptor alpha (PPARalpha) agonist Wy-14,643. A diethylnitrosamine-induced liver cancer model was used to evaluate the role of Myc in hepatocarcinogenesis. RESULTS: Tamoxifen administration induced recombination of Myc specifically in hepatocytes of Myc(fl/fl,ERT2-Cre) mice. When treated with a known hepatocellular proliferative stimulus Wy-14,643, Myc(fl/fl,ERT2-Cre) mice showed a lower liver/body weight ratio and suppressed hepatocyte proliferation as compared to Myc(fl/fl) mice. Hepatic expression of cell cycle control genes, DNA repair genes, and Myc target gene miRNAs were upregulated in Wy-14,643-treated Myc(fl/fl) mouse livers, but not in Wy-14,643-treated Myc(fl/fl,ERT2-Cre) livers. However, no differences were observed in the lipid-lowering effect of Wy-14,643 between Myc(fl/fl,ERT2-Cre) and Myc(fl/fl) mice, consistent with no differences in the expression of several PPARalpha target genes involved in fatty acid beta-oxidation. Moreover, when subjected to the diethylnitrosamine liver cancer bioassay, Myc(fl/fl,ERT2-Cre) mice exhibited a markedly lower incidence of tumor formation compared with Myc(fl/fl) mice. CONCLUSIONS: Myc plays an essential role in hepatocellular proliferation and liver tumorigenesis. |
