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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
1
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pubmed:dateCreated |
1993-6-9
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pubmed:abstractText |
Hs578T human breast cancer cells secrete insulin-like growth factor binding protein (IGFBP)-3 (41-kDa and 39-kDa) and IGFBP-4 (24-kDa) as major BP species. In addition, cell surface-associated IGFBP-3 is demonstrable by use of cell monolayer affinity cross-linking or by employing immunoperoxidase staining of the cell surface with specific polyclonal anti-human IGFBP-3 antibodies (alpha IGFBP-3gl and alpha IGFBP-3ngl). In this study, we have demonstrated that regulation of Hs578T IGFBP-3 by IGF peptides is specific, non-receptor mediated, and post-translational by showing: 1) dose-dependent increase of IGFBP-3 in conditioned media(CM) following addition of IGF-I and IGF-II (maximum 8-13-fold increase at 100 ng/ml concentration), but not by insulin up to 1 microgram/ml; 2) confirmation of IGF-induced increases in CM concentrations of IGFBP-3 by means of Western ligand blot, affinity cross-linking, and IGFBP-3-specific radioimmunoassay; 3) increase of IGFBP-3 in CM by addition of IGF analogs which retain full affinity for IGFBPs ([Leu27]IGF-II and [Tyr55,Gln56]IGF-I), but not by IGF analogs which have significantly decreased affinity for IGFBPs ([Gln3,Ala4,Tyr15,Leu16]IGF-I, [Gln6,Ala7,Tyr18,Leu19,Leu27]IGF-II and IGF-I/insulin hybrid); 4) no change in IGFBP-3 mRNA following addition of IGFs; 5) existence of metal ion-dependent IGFBP-3 specific protease in CM and protection of IGFBP-3 from protease by formation of [IGF:IGFBP-3] complexes; and 6) release of cell surface-associated IGFBP-3 into CM by addition of IGF peptides. These studies demonstrate that IGF peptides regulate CM concentrations of IGFBP-3 through non-receptor mediated events, including dissociation of cell surface-associated IGFBP-3 and protection of IGFBP-3 from protease activity.
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pubmed:grant | |
pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Carrier Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Culture Media, Conditioned,
http://linkedlifedata.com/resource/pubmed/chemical/Endopeptidases,
http://linkedlifedata.com/resource/pubmed/chemical/Insulin,
http://linkedlifedata.com/resource/pubmed/chemical/Insulin-Like Growth Factor Binding...,
http://linkedlifedata.com/resource/pubmed/chemical/Receptor, IGF Type 2,
http://linkedlifedata.com/resource/pubmed/chemical/Somatomedins,
http://linkedlifedata.com/resource/pubmed/chemical/insulin-like growth factor binding...
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pubmed:status |
MEDLINE
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pubmed:month |
Mar
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pubmed:issn |
0956-523X
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
3
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
84-7
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pubmed:dateRevised |
2011-11-17
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pubmed:meshHeading |
pubmed-meshheading:7683543-Blotting, Northern,
pubmed-meshheading:7683543-Blotting, Western,
pubmed-meshheading:7683543-Breast Neoplasms,
pubmed-meshheading:7683543-Carrier Proteins,
pubmed-meshheading:7683543-Culture Media, Conditioned,
pubmed-meshheading:7683543-Densitometry,
pubmed-meshheading:7683543-Endopeptidases,
pubmed-meshheading:7683543-Humans,
pubmed-meshheading:7683543-Insulin,
pubmed-meshheading:7683543-Insulin-Like Growth Factor Binding Proteins,
pubmed-meshheading:7683543-Protein Biosynthesis,
pubmed-meshheading:7683543-Receptor, IGF Type 2,
pubmed-meshheading:7683543-Somatomedins,
pubmed-meshheading:7683543-Transcription, Genetic,
pubmed-meshheading:7683543-Tumor Cells, Cultured
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pubmed:year |
1993
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pubmed:articleTitle |
Insulin-like growth factor binding protein (IGFBP)-3 levels in conditioned media of Hs578T human breast cancer cells are post-transcriptionally regulated.
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pubmed:affiliation |
Department of Pediatrics, Stanford University School of Medicine, CA 94305.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.,
Research Support, Non-U.S. Gov't
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