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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1998-10-8
pubmed:abstractText
So far, the physiological role of insulin-like growth factor binding protein-2 (IGFBP-2) has not been demonstrated directly. Therefore, we transfected 293 cells with an expression vector containing the CMV promoter and the complete cDNA of mouse IGFBP-2. Secretion of bioactive IGFBP-2 into conditioned medium was demonstrated by Western ligand and Western immunoblotting and quantified by specific RIA. For the analysis of cell proliferation three clones exhibiting either high or low/no IGFBP-2 expression were selected and compared to non-transfected parental 293 cells. IGFBP-2 secreting clones displayed reduced conversion of thiazolyl blue when compared to negative clones or non-transfected parental 293 cells (P < 0.01). The lower growth activity measured in the IGFBP-2 secreting clones was compensated in great part by the administration of exogenous IGF-I or -II. Conditioned media of IGFBP-2 secreting clones inhibited growth of IGF-responsive colon tumor cell lines (LS513, HT-29) while those of negative clones did not. In addition, conditioned medium from a clone expressing high levels of IGFBP-2 inhibited anchorage-independent growth of LS513 and HT-29 cells. In contrast, growth of an IGF-unresponsive tumor cell line (Co-115) was not affected by the conditioned media. We hypothesize that IGFBP-2 might sequester the IGFs and thus prevent them from transferring their mitogenic signals.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0014-5793
pubmed:author
pubmed:issnType
Print
pubmed:day
4
pubmed:volume
434
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
329-34
pubmed:dateRevised
2004-11-17
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Insulin-like growth factor-binding protein-2 inhibits proliferation of human embryonic kidney fibroblasts and of IGF-responsive colon carcinoma cell lines.
pubmed:affiliation
Lehrstuhl für Molekulare Tierzucht und Haustiergenetik/Genzentrum, Ludwig-Maximilians-Universität, Munich, Germany. hoeflich@lmb.uni-muenchen.de
pubmed:publicationType
Journal Article