Transcription of mouse mammary tumor virus (MMTV) RNA from integrated proviral DNA is stimulated rapidly and specifically by glucocorticoids. Molecular and genetic approaches will be used to identify genes and gene products that are involved in glucocorticoid regulation of MMTV gene expression. A procedure employing ribonucleoside (beta-S)triphosphates, Hg-Sepharose column chromatography, and nucleic acid filter hybridization has been established for measuring initiation of new MMTV RNA chains in preparations of cell nuclei. This cell free system will be used to determine whether glucocorticoids control MMTV RNA synthesis at the level of transcription initiation. The sites of initiation of MMTV RNA chains in vitro and in vivo will be compared by S1 nuclear mapping. Nuclei from MMTV-infected cells or, alternatively, nuclei from cells transfected with SV40/MMTV recombinant vectors, will be used to establish a system in which initiation of MMTV RNA chains is stimulated by the addition of glucocorticoid hormone and receptors. A combination of immunological and pharmacological procedures will be used to select novel glucocorticoid response variants from clones of MMTV-infected mouse lymphomacells with two responses: stimulation of MMTV gene expression and glucocorticoid-induced cytolysis. Specific programs are proposed for obtaining and charcterizing (biochemically and genetically) variants with lesions in MMTV structural genes, MMTV DNA sequences that regulate transcription and hormone inductibility, cellular genes necessry for posttranscriptional processing of MMTV proteins, and other cellular genes (including but not limited to the glucocorticoid receptor) that may be necessary for each hormone response. Programmed regulation of gene expression is essential for the normal development of an organism. Cancer is caused by a breakdown in thenormal control of specific genes. The proposed project will increase understanding of the role of hormones in development, differentiation, and malignancy.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Modified Research Career Development Award (K04)
Project #
5K04CA001149-05
Application #
3071712
Study Section
Molecular Biology Study Section (MBY)
Project Start
1985-09-01
Project End
1988-06-30
Budget Start
1987-07-01
Budget End
1988-06-30
Support Year
5
Fiscal Year
1987
Total Cost
Indirect Cost
Name
University of Southern California
Department
Type
Schools of Medicine
DUNS #
041544081
City
Los Angeles
State
CA
Country
United States
Zip Code
90033
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Snider, L D; Corey, J L; Rabindran, S K et al. (1990) Characterization of oligosaccharide chains on mouse mammary tumor virus envelope proteins and the implications for the mechanism of their glucocorticoid regulated processing. Mol Endocrinol 4:749-57
Nori, M; Stallcup, M R (1988) Temperature-sensitive transport of glycoproteins to the surface of a variant mouse lymphoma cell line. Mol Cell Biol 8:833-42
Zhang-Keck, Z Y; Stallcup, M R (1988) Optimized reaction conditions and specific inhibitors for initiation of transcription by RNA polymerase II in nuclei from cultured mammalian cells. J Biol Chem 263:3513-20
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Rabindran, S K; Danielsen, M; Stallcup, M R (1987) Glucocorticoid-resistant lymphoma cell variants that contain functional glucocorticoid receptors. Mol Cell Biol 7:4211-7