Linked Life Data

1709588

Source:http://linkedlifedata.com/resource/pubmed/id/1709588

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
1991-6-21
pubmed:abstractText
Central nervous system (CNS) tumor cells possess specific receptors for insulin-like growth factors (IGFs) and respond to the growth-promoting effects of IGFs in cell culture. In the present study, we asked whether CNS tumors also produce IGF-binding proteins (BPs) which may modulate the effects of IGFs on CNS tumor cells. Primary cell cultures were established from 20 CNS tumors. Dot blot analysis with 125I-labeled recombinant human IGF-I revealed IGF-binding activity in serum-free conditioned medium from 5 of 7 meningiomas, 7 of 8 malignant gliomas, and 3 of 5 other CNS tumors. Specific IGF BPs in conditioned medium were characterized further by Western ligand and immunoblotting, affinity labeling, and precipitation with specific antibodies against human IGFBP-1, -2, and -3. All conditioned media tested contained an Mr 35,000 BP which was recognized by antiserum against IGFBP-2 and an Mr 24,000 BP that was not recognized by available antisera. Medium conditioned by meningiomas (and one glioma) also contained Mr 45,000 and 50,000 IGF BPs, similar in size and/or immunological properties to growth hormone-dependent BPs present in normal human serum (IGFBP-3). Ligand blotting also showed that meningiomas produce an Mr 29,000 BP; immunoblotting and immunoprecipitation of affinity-labeled IGF-BP complexes confirmed that this BP is recognized by antiserum against IGFBP-1. Immunohistochemistry with specific monoclonal antibodies demonstrated that IGFBP-1 is abundant in pathological specimens of meningiomas and that lower amounts also are detected in malignant gliomas. We conclude that human CNS tumor cells produce a variety of IGF BPs in cell culture, including several that are similar in size and immunological properties to previously characterized human IGF BPs. Immunohistochemistry with specific monoclonal antibodies against IGFBP-1 confirms that this BP is present in vivo, further supporting the concept that IGF BPs may contribute to the regulation of growth in human CNS tumors.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0008-5472
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
51
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3030-6
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Production of insulin-like growth factor-binding proteins by human central nervous system tumors.
pubmed:affiliation
Department of Medicine, University of Illinois College of Medicine, Chicago.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't