Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
27
pubmed:dateCreated
1988-10-19
pubmed:abstractText
Epidermal growth factor (EGF) stimulated the rapid accumulation of inositol trisphosphate in WB cells, a continuous line of rat hepatic epithelial cells. Since we previously had shown that EGF stimulates EGF receptor synthesis in these cells, we tested whether hormones that stimulate PtdIns(4,5)P2 hydrolysis would increase EGF receptor protein synthesis and mRNA levels. Epinephrine, angiotensin II, and [Arg8]vasopressin activate phospholipase C in WB cells as evidenced by the accumulation of the inositol phosphates, inositol monophosphate, inositol bisphosphate, and inositol trisphosphate. A 3-4-h treatment with each hormone also increased the rate of EGF receptor protein synthesis by 3-6-fold as assessed by immunoprecipitation of EGF receptor from [35S]methionine-labeled cells. Northern blot analyses of WB cell EGF receptor mRNA levels revealed that agents linked to the phosphoinositide signaling system increased receptor mRNA content within 1-2 h. A maximal increase of 3-7-fold was observed after a 3-h exposure to EGF and hormones. The phorbol ester, 12-O-tetradecanoylphorbol 13-acetate (TPA), which activates protein kinase C also stimulated EGF receptor synthesis. Pretreatment of WB cells for 18 h with high concentrations of TPA "down-regulated" protein kinase C and blocked TPA-directed EGF receptor mRNA synthesis. In contrast, the effect of EGF on EGF receptor mRNA levels was not significantly decreased by TPA pretreatment. Epinephrine-induced increases in EGF receptor mRNA were reduced from 4- to 2-fold. Similarly, 18 h TPA pretreatment abolished the effect of TPA on EGF receptor protein synthesis but did not affect EGF-dependent EGF receptor protein synthesis. The 18-h TPA pretreatment diminished by 30-50% the induction of receptor protein synthesis by epinephrine or angiotensin II. We conclude that in WB cells EGF receptor synthesis can be regulated by EGF and other hormones that stimulate PtdIns(4,5)P2 hydrolysis. In these cells, EGF receptor synthesis appears to be regulated by several mechanism: one pathway is dependent upon EGF receptor activation and can operate independently of protein kinase C activation; another pathway is correlated with PtdIns(4,5)P2 hydrolysis and is dependent, at least in part, upon protein kinase C activation.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Angiotensin II, http://linkedlifedata.com/resource/pubmed/chemical/Arginine Vasopressin, http://linkedlifedata.com/resource/pubmed/chemical/Epidermal Growth Factor, http://linkedlifedata.com/resource/pubmed/chemical/Epinephrine, http://linkedlifedata.com/resource/pubmed/chemical/Inositol, http://linkedlifedata.com/resource/pubmed/chemical/Inositol Phosphates, http://linkedlifedata.com/resource/pubmed/chemical/Phosphatidylinositol 4,5-Diphosphate, http://linkedlifedata.com/resource/pubmed/chemical/Phosphatidylinositols, http://linkedlifedata.com/resource/pubmed/chemical/Protein Kinase C, http://linkedlifedata.com/resource/pubmed/chemical/RNA, Messenger, http://linkedlifedata.com/resource/pubmed/chemical/Receptor, Epidermal Growth Factor, http://linkedlifedata.com/resource/pubmed/chemical/Tetradecanoylphorbol Acetate
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
263
pubmed:owner
NLM
pubmed:authorsComplete
N
pubmed:pagination
13868-74
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed-meshheading:2843541-Angiotensin II, pubmed-meshheading:2843541-Animals, pubmed-meshheading:2843541-Arginine Vasopressin, pubmed-meshheading:2843541-Cell Line, pubmed-meshheading:2843541-Enzyme Activation, pubmed-meshheading:2843541-Epidermal Growth Factor, pubmed-meshheading:2843541-Epinephrine, pubmed-meshheading:2843541-Epithelium, pubmed-meshheading:2843541-Hydrolysis, pubmed-meshheading:2843541-Inositol, pubmed-meshheading:2843541-Inositol Phosphates, pubmed-meshheading:2843541-Kinetics, pubmed-meshheading:2843541-Liver, pubmed-meshheading:2843541-Phosphatidylinositol 4,5-Diphosphate, pubmed-meshheading:2843541-Phosphatidylinositols, pubmed-meshheading:2843541-Protein Kinase C, pubmed-meshheading:2843541-RNA, Messenger, pubmed-meshheading:2843541-Rats, pubmed-meshheading:2843541-Receptor, Epidermal Growth Factor, pubmed-meshheading:2843541-Tetradecanoylphorbol Acetate
pubmed:year
1988
pubmed:articleTitle
Epidermal growth factor (EGF) and hormones stimulate phosphoinositide hydrolysis and increase EGF receptor protein synthesis and mRNA levels in rat liver epithelial cells. Evidence for protein kinase C-dependent and -independent pathways.
pubmed:affiliation
Lineberger Cancer Research Center, University of North Carolina, Chapel Hill.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.