Hormonal Regulation of Expression of the Endogenous and Transfected Human Growth Hormone Gene
Autor: | Paul R. Findell, Pamela L. Mellon, Charles B. Wilson, John D. Baxter, Randi Isaacs |
---|---|
Rok vydání: | 1987 |
Předmět: |
Adenoma
endocrine system medicine.medical_specialty Pituitary gland medicine.medical_treatment Radioimmunoassay Endogeny Biology Transfection Dexamethasone Endocrinology Internal medicine Gene expression Tumor Cells Cultured medicine Animals Humans Insulin Pituitary Neoplasms RNA Messenger Molecular Biology Genetic transfer General Medicine Blotting Northern Gene Expression Regulation Neoplastic Somatropin medicine.anatomical_structure Growth Hormone embryonic structures Triiodothyronine hormones hormone substitutes and hormone antagonists Glucocorticoid Hormone medicine.drug |
Zdroj: | Molecular Endocrinology. 1:569-576 |
ISSN: | 1944-9917 0888-8809 |
Popis: | Expression of the endogenous human GH (hGH) gene in response to glucocorticoids, thyroid hormone, and insulin was studied in cultures of dispersed GH-secreting human pituitary adenomas. Results were compared to those obtained when the hGH gene was transfected into rat pituitary tumor cells (GC). In the human pituitary cells the glucocorticoid dexamethasone [(Dex) 10(-6) M] increased the release of GH and the levels of GH mRNA by 2 to 4-fold (P less than 0.05). T3 (10(-8) M) had no effect on GH mRNA but increased hGH release by 2- to 6-fold (P less than 0.01). Insulin (5 x 10(-9) M) alone had no significant effect on either hGH mRNA or protein, but blunted the effect of Dex. Among 11 of 18 GC cell clones transfected with the hGH gene with detectable hGH mRNA expression, Dex increased hGH mRNA levels in seven and T3 treatment reduced hGH mRNA levels in eight. Conversely, rat GH mRNA levels from the endogenous rat gene were increased by either Dex or T3 in all 18 clones. Insulin alone or in combination with T3 or Dex was found to increase hGH mRNA levels in some cell lines and to decrease hGH mRNA levels in others; these effects were correlated strongly (r = 0.88; P less than 0.001) with the influence of insulin on the endogenous rat GH gene, implying that individual cellular differences can simultaneously affect the insulin responsiveness of both genes.(ABSTRACT TRUNCATED AT 250 WORDS) |
Databáze: | OpenAIRE |
Externí odkaz: |