The overall objective of this research proposal is to study the role and regulation of the glutamine transporter system ASC in hepatocellular transformation. The proposal contains four specific hypotheses: 1) Accelerated rates of glutamine uptake via System ASC are a consistent feature of human hepatomas. 2) ASC mediated glutamine transport is necessary, but not alone sufficient for a tumorigenic phenotype. 3) Growth of human hepatomas is regulated by delivery of glutamine to the cytoplasm. 4) System ASC activity is regulated by cellular growth status. To test these four hypotheses, the investigators propose four specific aims: 1) They will examine glutamine transport in cells or plasma membrane vesicles from surgical biopsies that include hepatic tumor and normal surrounding parenchyma. 2) A nontumorigenic immortalized human liver epithelial cell line (THLE-5B) will be stably transfected with the hepatoma ASC gene and injected into nude mice for evaluation of tumorigenic potential. 3) Human hepatomas and immortalized human liver cells will be grown in the presence of physiologic glutamine levels and in the presence or absence of excess System ASC substrates and the effects on proliferation evaluated. 4) ASC mediated glutamine uptake will be evaluated at both the activity and molecular levels in synchronized hepatoma and THLE-5B cells after growth modulation by nutrient supply or biochemicals.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
First Independent Research Support & Transition (FIRST) Awards (R29)
Project #
5R29CA069505-06
Application #
6376206
Study Section
Metabolic Pathology Study Section (MEP)
Project Start
1997-04-01
Project End
2003-03-31
Budget Start
2001-04-01
Budget End
2003-03-31
Support Year
6
Fiscal Year
2001
Total Cost
$111,115
Indirect Cost
Name
Saint Louis University
Department
Biology
Type
Schools of Arts and Sciences
DUNS #
City
Saint Louis
State
MO
Country
United States
Zip Code
63103
Fuchs, Bryan C; Bode, Barrie P (2005) Amino acid transporters ASCT2 and LAT1 in cancer: partners in crime? Semin Cancer Biol 15:254-66
Fuchs, Bryan C; Perez, J Christian; Suetterlin, Julie E et al. (2004) Inducible antisense RNA targeting amino acid transporter ATB0/ASCT2 elicits apoptosis in human hepatoma cells. Am J Physiol Gastrointest Liver Physiol 286:G467-78
Bode, Barrie P; Fuchs, Bryan C; Hurley, Bryan P et al. (2002) Molecular and functional analysis of glutamine uptake in human hepatoma and liver-derived cells. Am J Physiol Gastrointest Liver Physiol 283:G1062-73
Bode, B P (2001) Recent molecular advances in mammalian glutamine transport. J Nutr 131:2475S-85S; discussion 2486S-7S
Bode, B P; Souba, W W (1999) Glutamine transport and human hepatocellular transformation. JPEN J Parenter Enteral Nutr 23:S33-7
Bode, B P; Reuter, N; Conroy, J L et al. (1998) Protein kinase C regulates nutrient uptake and growth in hepatoma cells. Surgery 124:260-7;discussion 267-8