These investigations should enhance our understanding of the structure, organization, and regulation of thyrotropin (TSH) genes in mouse and man. This laboratory has already cloned cDNAs to mouse alpha and beta TSH mRNAs extracted from a TSH-secreting pituitary tumor and determined their nucleotide sequences. The cloning of human TSH cDNAs using post-mortem human pituitary glands as the source of mRNA is ongoing. A study of the structure and chromosomal location of TSH genes in mouse and man has been completed using genomic libraries for selection of TSH genes and somatic cell hybrids of known chromosomal content for assignment of TSH genes to specify chromosomes. Chromatin structure of TSH genes, as reflected by DNase sensitivity and methylation, will be evaluated during the evolution of mouse TSH-secreting pituitary tumors. The regions of the 5'-flanking sequences of the alpha and beta TSH genes important for transcription will be determined by the in vitro transcription of specific gene deletion mutants in a HeLa cell extract system. The effects on TSH gene expression of thyroid hormone, glucocorticoids, bromergocryptine, estrogen, and thyrotropin-releasing hormone (TRH) have been investigated. Alpha and beta TSH genes are affected discordantly by thyroid hormone. The molecular level of regulation is being studied: transcription, mRNA processing, pretranslational effects, translational efficiency, and posttranslational effects. TSH genes will be transferred into recipient cells to study their expression and regulation. These basic studies will be performed in conjunction with ongoing clinical studies of patients with pituitary resistance to thyroid hormones and the regulation of their inappropriate TSH secretion, particularly by the dopamine agonist bromergocryptine. These investigations should add considerably to our knowledge of the regulation of TSH gene expression and the mechanism of action of thyroid hormones. (C)

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA023185-10
Application #
3166042
Study Section
Endocrinology Study Section (END)
Project Start
1977-07-01
Project End
1989-04-30
Budget Start
1986-05-01
Budget End
1987-04-30
Support Year
10
Fiscal Year
1986
Total Cost
Indirect Cost
Name
Sloan-Kettering Institute for Cancer Research
Department
Type
DUNS #
064931884
City
New York
State
NY
Country
United States
Zip Code
10065
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Smith, T J; Drummond, G S (1991) Retinoic acid can enhance the stimulation by thyroid hormone of heme oxygenase activity in the liver of thyroidectomized rats. Biochim Biophys Acta 1075:119-22
Dacou-Voutetakis, C; Feltquate, D M; Drakopoulou, M et al. (1990) Familial hypothyroidism caused by a nonsense mutation in the thyroid-stimulating hormone beta-subunit gene. Am J Hum Genet 46:988-93
Gurr, J A; Januszeski, M M; Tidikis, I M et al. (1990) Thyroid hormone regulates expression of the thyrotropin beta-subunit gene from both transcription start sites in the mouse and rat. Mol Cell Endocrinol 71:185-93
Gurr, J A; Kourides, I A (1989) Regulation of the transfected human glycoprotein hormone alpha-subunit gene by dexamethasone and thyroid hormone. DNA 8:473-80
Dracopoli, N C; Rose, E; Whitfield, G K et al. (1988) Two thyroid hormone regulated genes, the beta-subunits of nerve growth factor (NGFB) and thyroid stimulating hormone (TSHB), are located less than 310 kb apart in both human and mouse genomes. Genomics 3:161-7
Smith, T J; Drummond, G S (1988) Thyroid hormone regulation of heme synthesis in rat liver. Endocrinology 122:1964-7
Nicolis, G; Shimshi, M; Allen, C et al. (1988) Gonadotropin-producing pituitary adenoma in a man with long-standing primary hypogonadism. J Clin Endocrinol Metab 66:237-41
Coccaro, E F; Siever, L J; Kourides, I A et al. (1988) Central serotoninergic stimulation by fenfluramine challenge does not affect plasma thyrotropin-stimulating hormone levels in man. Neuroendocrinology 47:273-6
Guidon Jr, P T; Whitfield, G K; Porti, D et al. (1988) The human thyrotropin beta-subunit gene differs in 5' structure from murine TSH-beta genes. DNA 7:691-9

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