Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1995-8-3
pubmed:abstractText
In mammosomatotropes GH3B6 cells, one of the primary responses to thyrotropin-releasing hormone (TRH) is the parallel induction of two proto-oncogenes, c-fos and jun B, which code for constituents of AP1 transcription factor. To better understand the mode of action of TRH and to look for possible functions of c-fos and jun B in these cells, we have investigated the role of different intracellular signals in the induction of each proto-oncogene on the one hand, and on prolactin (PRL) release and PRL gene expression on the other hand. Northern and dot-blot analyses revealed that the activation of protein kinase C (PKC)-, Ca(2+)- or adenylyl cyclase-dependent pathways acutely increased both c-fos and jun B transcripts. However, a gene specific responsiveness was revealed using phorbol 12-myristate 13-acetate (TPA) and several combined treatments. The simultaneous activation of PKC and Ca(2+)-dependent pathways resulted in synergistic stimulations of c-fos mRNA levels only. Consistently, ionomycin plus low doses of TPA solely reproduced the potent effect of TRH on c-fos transcripts. Data collected from TRH and TPA down-regulated cells indicated that TRH probably recruits TPA-dependent PKC isoforms for stimulating c-fos but not jun B transcripts. On the contrary, the TRH-induced stimulation of either proto-oncogene likely involves Ca(2+)-dependent mechanisms because calcium agonists and the peptide exert non-additive effects. Finally, the synergistic stimulations observed in response to TRH combined with forskolin, indicate that adenylyl cyclase-dependent mechanisms are interconnected with TRH-induced proto-oncogene expression. The overall study also reveals that among the agonists tested, the dihydropyridine Bay K 8644 and forskolin only were capable to induce a long-lasting stimulation of c-fos and jun B mRNA levels, concomitant to increased levels of PRL transcripts, as does TRH. Considering that AP1 is assumed to be involved in signal transmission from the cell surface to the nucleus, it might be thus proposed that a common stimulation of c-fos and jun B gene expression is possibly involved in the activation of the PRL gene. On the other hand, the systematic coincidence between acute PRL release and proto-oncogenes expression suggest a role for c-fos and jun B in the control of genes involved in the secretory process.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Adenylate Cyclase, http://linkedlifedata.com/resource/pubmed/chemical/Calcium, http://linkedlifedata.com/resource/pubmed/chemical/Cyclic AMP, http://linkedlifedata.com/resource/pubmed/chemical/Forskolin, http://linkedlifedata.com/resource/pubmed/chemical/Ionomycin, http://linkedlifedata.com/resource/pubmed/chemical/Neoplasm Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Nuclear Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Phorbol 12,13-Dibutyrate, http://linkedlifedata.com/resource/pubmed/chemical/Prolactin, http://linkedlifedata.com/resource/pubmed/chemical/Proto-Oncogene Proteins c-fos, http://linkedlifedata.com/resource/pubmed/chemical/Proto-Oncogene Proteins c-jun, http://linkedlifedata.com/resource/pubmed/chemical/RNA, Messenger, http://linkedlifedata.com/resource/pubmed/chemical/Tetradecanoylphorbol Acetate, http://linkedlifedata.com/resource/pubmed/chemical/Thyrotropin-Releasing Hormone
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0303-7207
pubmed:author
pubmed:issnType
Print
pubmed:volume
107
pubmed:geneSymbol
c-fos, fos, jun, jun B
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
29-40
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:7796933-Adenylate Cyclase, pubmed-meshheading:7796933-Animals, pubmed-meshheading:7796933-Calcium, pubmed-meshheading:7796933-Clone Cells, pubmed-meshheading:7796933-Cyclic AMP, pubmed-meshheading:7796933-Forskolin, pubmed-meshheading:7796933-Gene Expression Regulation, Neoplastic, pubmed-meshheading:7796933-Genes, fos, pubmed-meshheading:7796933-Genes, jun, pubmed-meshheading:7796933-Ionomycin, pubmed-meshheading:7796933-Neoplasm Proteins, pubmed-meshheading:7796933-Nuclear Proteins, pubmed-meshheading:7796933-Phorbol 12,13-Dibutyrate, pubmed-meshheading:7796933-Pituitary Gland, Anterior, pubmed-meshheading:7796933-Pituitary Neoplasms, pubmed-meshheading:7796933-Prolactin, pubmed-meshheading:7796933-Proto-Oncogene Proteins c-fos, pubmed-meshheading:7796933-Proto-Oncogene Proteins c-jun, pubmed-meshheading:7796933-RNA, Messenger, pubmed-meshheading:7796933-Rats, pubmed-meshheading:7796933-Signal Transduction, pubmed-meshheading:7796933-Tetradecanoylphorbol Acetate, pubmed-meshheading:7796933-Thyrotropin-Releasing Hormone, pubmed-meshheading:7796933-Tumor Cells, Cultured
pubmed:year
1995
pubmed:articleTitle
Multiple intracellular signallings are involved in thyrotropin-releasing hormone (TRH)-induced c-fos and jun B mRNA levels in clonal prolactin cells.
pubmed:affiliation
Groupe de Biologie de la Cellule Neuroendocrine, CNRS URA 1115, Collège de France, Paris.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't