Hepatocellular carcinoma is one of the most prevalent tumors worldwide. Differentiated hepatocytes are quiescent yet have the ability to proliferate in response to hepatocellular injury, partial hepatectomy and growth mediators, such as transforming growth factor alpha (TGFalpha). Although TGFalpha is a potent inducer of hepatocyte proliferation and liver tumorigenesis, the molecular mechanisms responsible for the effects of this cytokine are only partially understood. Increased transcriptional activity through phosphorylations of rat, chicken or human C/EBPbeta is induced by stimulators of cell proliferation. We have reported that primary hepatocytes isolated from C/EBPbeta-/-, but not from C/EBPbeta+/+, mice fail to proliferate in response to TGFalpha. The long-term objectives of this application are to understand the molecular mechanisms responsible for the development of hepatocellular carcinoma.
The specific aim i s to analyze the role of a site-specific phosphorylation of C/EBPbeta (Thr217) on the development of hepatocellular carcinoma. The presence of phosphorylated C/EBPbeta in human hepatocellular carcinoma will be determined with specific antibodies against this epitope. Similarly, gain-of-function mutations of the C/EBP? phosphorylation site (conserved in humans) could contribute to the pathogenesis of liver tumors in patients with chronic liver diseases. In addition, the PI will receive intensive training in the state-of-the-art genetics, pathophysiological and clinical aspects of hepatocellular carcinoma, as well as research presentations and the reviewing of grants and manuscripts.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Scientist Development Award - Research & Training (K01)
Project #
5K01CA096932-03
Application #
6799321
Study Section
Subcommittee G - Education (NCI)
Program Officer
Ojeifo, John O
Project Start
2002-09-26
Project End
2007-08-31
Budget Start
2004-09-01
Budget End
2005-08-31
Support Year
3
Fiscal Year
2004
Total Cost
$146,412
Indirect Cost
Name
University of California San Diego
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
804355790
City
La Jolla
State
CA
Country
United States
Zip Code
92093
Buck, Martina; Solis-Herruzo, Jose; Chojkier, Mario (2016) C/EBP?-Thr217 Phosphorylation Stimulates Macrophage Inflammasome Activation and Liver Injury. Sci Rep 6:24268
Chojkier, Mario; Elkhayat, Hisham; Sabry, Dina et al. (2012) Pioglitazone decreases hepatitis C viral load in overweight, treatment naïve, genotype 4 infected-patients: a pilot study. PLoS One 7:e31516
Buck, Martina; Chojkier, Mario (2011) C/EBP?-Thr217 phosphorylation signaling contributes to the development of lung injury and fibrosis in mice. PLoS One 6:e25497
Ramamoorthy, Sonia; Donohue, Michael; Buck, Martina (2009) Decreased Jun-D and myogenin expression in muscle wasting of human cachexia. Am J Physiol Endocrinol Metab 297:E392-401
Feldstein, Ariel; Kleiner, David; Kravetz, David et al. (2009) Severe hepatocellular injury with apoptosis induced by a hepatitis C polymerase inhibitor. J Clin Gastroenterol 43:374-81
Buck, Martina (2008) Direct infection and replication of naturally occurring hepatitis C virus genotypes 1, 2, 3 and 4 in normal human hepatocyte cultures. PLoS One 3:e2660
Buck, Martina (2008) A novel domain of BRCA1 interacts with p53 in breast cancer cells. Cancer Lett 268:137-45
Buck, Martina (2008) Targeting ribosomal S-6 kinase for the prevention and treatment of liver injury and liver fibrosis. Drug News Perspect 21:301-6
Buck, Martina; Chojkier, Mario (2007) C/EBPbeta phosphorylation rescues macrophage dysfunction and apoptosis induced by anthrax lethal toxin. Am J Physiol Cell Physiol 293:C1788-96
Buck, Martina; Chojkier, Mario (2007) C/EBPbeta associates with caspase 8 complex proteins and modulates apoptosis in hepatic stellate cells. J Clin Gastroenterol 41:S295-9

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