The alpha-fetoprotein (AFP) gene, an important experimental system for the study of developmental gene controls, is expressed at high levels in fetal liver and yolk sac, but silenced after birth. AFP gene controls thus mediate high level transcription, tissue-specific and developmental - stage-specific gene expression, and developmental gene silencing. Many cancers reverse this silencing, either by-passing a repressor or recapitulating fetal gene controls. The AFP gene is very accessible to experimental manipulation; its extensive study in carcinogenesis makes it an unusually attractive system for analyzing fundamental gene control mechanisms. Sequence and functional analysis show the transcription control region of the AFP gene to be extraordinarily complex.
The First Aim i s to better define the AFP gene transcription control elements, by constructing plasmids containing individual control elements and transfecting them into liver-derived cells. Experiments will focus on resolving the AFP-gene repressor from the promoter and regions that control interactions between distant enhancers and promoters.
The Second Aim win analyze how these elements regulate tissue and developmental specificity of expression, by studying them in combination with heterologous gene controls.
The Third Aim will study interactions of the gene controls with several agents that repress AFP: phorbol ester, serum, and glucocorticoid. Other experiments will study how oncogenes interact with the transcription controls, and characterize oncogenes that bypass the AFP repressor.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
2R01CA043909-04A1
Application #
3186379
Study Section
Pathology B Study Section (PTHB)
Project Start
1987-07-01
Project End
1994-06-30
Budget Start
1991-07-15
Budget End
1992-06-30
Support Year
4
Fiscal Year
1991
Total Cost
Indirect Cost
Name
University of Pittsburgh
Department
Type
Schools of Medicine
DUNS #
053785812
City
Pittsburgh
State
PA
Country
United States
Zip Code
15213
Block, G D; Locker, J; Bowen, W C et al. (1996) Population expansion, clonal growth, and specific differentiation patterns in primary cultures of hepatocytes induced by HGF/SF, EGF and TGF alpha in a chemically defined (HGM) medium. J Cell Biol 132:1133-49
Ohmura, T; Columbano, G L; Columbano, A et al. (1996) 9-cis retinoic acid is a direct hepatocyte mitogen in rats. Life Sci 58:PL211-216
Ohmura, T; Ledda-Columbano, G M; Piga, R et al. (1996) Hepatocyte proliferation induced by a single dose of a peroxisome proliferator. Am J Pathol 148:815-24
Li, C; Locker, J; Wan, Y J (1996) RXR-mediated regulation of the alpha-fetoprotein gene through an upstream element. DNA Cell Biol 15:955-63
Jin, J R; Wen, P; Locker, J (1995) Enhancer sharing in a plasmid model containing the alpha-fetoprotein and albumin promoters. DNA Cell Biol 14:267-72
Wan, Y J; Pan, T; Wang, L et al. (1995) 9-cis-retinoic acid is more effective than all-trans-retinoic acid in upregulating expression of the alpha-fetoprotein gene. J Mol Endocrinol 14:101-8
Groupp, E R; Crawford, N; Locker, J (1994) Characterization of the distal alpha-fetoprotein enhancer, a strong, long distance, liver-specific activator. J Biol Chem 269:22178-87
Wen, P; Locker, J (1994) A novel hepatocytic transcription factor that binds the alpha-fetoprotein promoter-linked coupling element. Mol Cell Biol 14:6616-26
Wen, P; Crawford, N; Locker, J (1993) A promoter-linked coupling region required for stimulation of alpha-fetoprotein transcription by distant enhancers. Nucleic Acids Res 21:1911-8
Yin, X Y; Smith, M L; Whiteside, T L et al. (1993) Abnormalities in the p53 gene in tumors and cell lines of human squamous-cell carcinomas of the head and neck. Int J Cancer 54:322-7

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