Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P61278 (somatostatin)
 22,083 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The cyclic AMP (cAMP) response elements (CREs) of the somatostatin and vasoactive intestinal peptide (VIP) promoters contain binding sites for CRE-binding protein (CREB) that are essential for cAMP-regulated transcription. Using F9 embryonal carcinoma cells, we show that the somatostatin and VIP promoters exhibit a differentiation-dependent cAMP response, demonstrating that these promoters are regulated by transcription factors that become active during differentiation. Lack of cAMP responsiveness of the somatostatin promoter in undifferentiated cells is not due to the absence of known positive-acting factors (the catalytic subunit of protein kinase A [cPKA] and CREB) or a general inhibition of protein kinase A activity. Since overexpression of exogenous cPKA and CREB is sufficient to activate the somatostatin promoter in undifferentiated cells, these findings suggest that a negative factor(s) represses endogenous cPKA and CREB. In contrast to their effects on somatostatin, exogenous CREB and cPKA do not activate the VIP promoter. Thus, despite coregulation during differentiation and the ability to bind CREB, the somatostatin and VIP promoters are not coordinately activated by CREB in undifferentiated F9 cells.
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PMID:Cyclic AMP response element-binding protein and the catalytic subunit of protein kinase A are present in F9 embryonal carcinoma cells but are unable to activate the somatostatin promoter. 134 42

Human teratocarcinoma cells in culture offer an in vitro system for studying certain aspects of embryonic differentiation. To gain some insight into regulatory systems that might be operative during early human development, we have characterized the alterations that occur in the hormonal responsiveness of human embryonal carcinoma cell adenylate cyclase with differentiation in response to 10 microM retinoic acid. Two cell lines CL12 and CL13, cloned from Tera 2 cells by Dr. C. F. Graham, have been used in these studies. Adenylate cyclase of CL12 and CL13 cells is stimulated in the presence of 10 microM GTP by epinephrine and calcitonin, with calcitonin being the most potent stimulator of cyclic AMP production. Exposure of these cells to retinoic acid leads to an arrest in growth and within 6 days to a differentiated cell population with a stable nonreversible phenotype. No changes in basal, GTP- and fluoride-stimulated adenylate cyclase activities are observed with retinoic acid treatment, but the cyclase of differentiated cells exhibits a greater stimulation by calcitonin (7.5-fold) and the appearance of a somatostatin inhibitory effect. Somatostatin specifically inhibits, by 25%, the hormonal stimulation of adenylate cyclase of cells treated for 5 days with retinoic acid. The increase in calcitonin stimulation of adenylate cyclase activity of the differentiated cells is related to an increase (congruent to 3-fold) in the number of hormonal receptors and not to a significant change in receptor binding affinity (Kd 4.6 X 10(8) M-1). These alterations in calcitonin and somatostatin responsiveness suggest a possible regulatory role for these hormones during embryonic development. Furthermore, the results indicate that changes in adenylate cyclase hormonal responsiveness might serve as useful markers during early stages of human embryonal carcinoma cell differentiation.
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PMID:Altered activation by calcitonin and inhibition by somatostatin of human embryonal carcinoma cell adenylate cyclase with retinoic acid-induced differentiation. 286 42

Treatment of P19 embryonal carcinoma cells with retinoic acid induces their differentiation into a population of cells consisting of neurons and other cell types normally derived from neuroectoderm. We used immunohistological and histochemical techniques to identify some of the neurotransmitters in the P19-derived neurons. The majority of neurons contained GABA, glutamic acid decarboxylase, and GABA-transaminase. Neuropeptide Y and somatostatin were less frequently found and both were partially co-expressed with GABA and with one another. Smaller numbers of cells were positive for tyrosine hydroxylase, DOPA decarboxylase, serotonin, calcitonin gene-related peptide, galanin and substance P. The variety and proportions of cells with different transmitter types were reproducible from one experiment to the next and varied very little over 40 days in culture except for cells containing enkephalin, which were abundant only in mature cultures of 32 days or more. Synapses formed between neurons and some contained both small clear and large dense-core vesicles within the presynaptic bouton. Because GABA, neuropeptide Y and somatostatin are abundant in P19-derived neurons as well as in embryonic neurons in rostral regions of the mammalian CNS, we suggest that the developmental events occurring in P19 cell cultures closely resemble those of the embryonic neuroectoderm.
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PMID:Neurons derived from P19 embryonal carcinoma cells have varied morphologies and neurotransmitters. 791 Jun 70