Linked Life Data

10861448

Source:http://linkedlifedata.com/resource/pubmed/id/10861448

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2000-7-13
pubmed:abstractText
Epidermal growth factor (EGF) and transforming growth factor-alpha (TGF-alpha) increase transcription of the gastrin gene, and the gastrin peptide may be phosphorylated by EGF-stimulated tyrosine kinase. Our aims were to compare EGF/TGF-alpha interactions in 2 human gastro-intestinal cell lines: MGLVA1, with a strong gastrin autocrine pathway, and C170HM2, with a weak pathway. Both cell lines expressed the TGF-alpha gene. MGLVA1 expressed TGF-alpha protein as determined by immuno-cytochemistry, which was absent in C170HM2. Both cell lines expressed the same level of EGF receptors, as assessed by flow cytometry; however, MGLVA1 did not have enhanced in vitro proliferation in response to EGF or TGF-alpha, unlike C170HM2. The basal growth of MGLVA1 was inhibited by anti-sera against TGF-alpha, the EGF receptor and G17. C170HM2 was not inhibited by any of the anti-sera. Neutralisation of TGF-alpha resulted in undetectable cell-associated progastrin levels in MGLVA1 (untreated had 391.7 fmol/5 x 10(6) cells). The progastrin level of C170HM2 remained unaffected. Tyrosine kinase activity, as assessed by phosphopeptide concentration, of unstimulated MGLVA1 was 2.6 times higher than that of C170HM2 in the cell membrane fraction (0.097 compared to 0.037 microg/mg protein, p < 0.001) and 4.8 times higher in the cytosolic fraction (0.269 compared to 0.056 microg/mg protein, p < 0.05). Following treatment with EGF, the phosphopeptide concentration increased in both the membrane and cytosolic fractions of both cell lines. Tyrphostin B42, which inhibits autophosphorylation of the EGF receptor, inhibited the basal growth of MGLVA1 (IC(50) 1.3 microM) and C170HM2 (9.5 microM, p < 0.05 from MGLVA1). Herbimycin, which inhibits pp60(c-src) kinase, reduced the basal growth of MGLVA1 (0.67 microM) but not C170HM2. Immunofluorescence studies confirmed the presence of tyrosine-phosphorylated proteins and pp60(c-src) within the cytoplasm of unstimulated MGLVA1 cells. There was no specific immunofluorescence for either parameter in C170HM2 cells until after treatment with EGF.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0020-7136
pubmed:author
pubmed:copyrightInfo
Copyright 2000 Wiley-Liss, Inc.
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
87
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
20-8
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed-meshheading:10861448-Blotting, Southern, pubmed-meshheading:10861448-Cell Division, pubmed-meshheading:10861448-Cell Line, pubmed-meshheading:10861448-Culture Media, Serum-Free, pubmed-meshheading:10861448-Digestive System, pubmed-meshheading:10861448-Dose-Response Relationship, Drug, pubmed-meshheading:10861448-Epidermal Growth Factor, pubmed-meshheading:10861448-Flow Cytometry, pubmed-meshheading:10861448-Gastrins, pubmed-meshheading:10861448-Humans, pubmed-meshheading:10861448-Immunohistochemistry, pubmed-meshheading:10861448-Luminescent Measurements, pubmed-meshheading:10861448-Phosphorylation, pubmed-meshheading:10861448-Protein Precursors, pubmed-meshheading:10861448-Protein-Tyrosine Kinases, pubmed-meshheading:10861448-Proto-Oncogene Proteins pp60(c-src), pubmed-meshheading:10861448-RNA, Messenger, pubmed-meshheading:10861448-Radioimmunoassay, pubmed-meshheading:10861448-Reverse Transcriptase Polymerase Chain Reaction, pubmed-meshheading:10861448-Transforming Growth Factor alpha
pubmed:year
2000
pubmed:articleTitle
Transforming growth factor-alpha-mediated growth pathways in human gastro-intestinal cell lines in relation to the gastrin autocrine pathway.
pubmed:affiliation
Academic Unit of Cancer Studies, University of Nottingham, Nottingham, UK. sue.watson@nottingham.ac.uk
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't