Synthesis and secretion by mouse 3T3 cells of an inhibitor of cell growth (mIGFBP-3): correlation with cell proliferation.
Our results show that stimulation by serum of dense cultures of 3T3 cells rapidly induced increased synthesis of a growth inhibitor (mIGFBP-3) capable of binding IGF. mIGFBP-3 was secreted by stimulated cells immediately after its synthesis, and accumulated in the medium. Accumulation of mIGFBP-3 in the medium increased, as a function of growth factor (bFGF, PDGF, insulin) concentrations and time. bFGF was the best stimulatory factor for both DNA synthesis and accumulation of mIGFBP-3 in the first 24 h of incubation. DNA synthesis was arrested after 48 h of incubation with bFGF when accumulation of mIGFBP-3 was maximal. Since we showed that mIGFBP-3 is able to inhibit bFGF stimulation of DNA synthesis in mouse fibroblasts, it is possible that the accumulation of mIGFBP-3 induces a feedback regulation of cell growth.
Liu
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L
Institut de Recherches Scientifiques sur le Cancer, Villejuif, France.
Blat
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C
Harel
L
L
D016475:3T3 Cells / Q000166:cytology / Q000378:metabolism*; D000818:Animals; D002352:Carrier Proteins / Q000096:biosynthesis* / Q000378:metabolism*; D002455:Cell Division / Q000187:drug effects; D017077:Culture Media, Conditioned; D004247:DNA / Q000096:biosynthesis; D006131:Growth Inhibitors / Q000096:biosynthesis* / Q000378:metabolism*; D018969:Insulin-Like Growth Factor Binding Proteins; D007700:Kinetics; D051379:Mice; D013002:Somatomedins / Q000096:biosynthesis* / Q000378:metabolism* / Q000494:pharmacology
D002352:Carrier Proteins; D017077:Culture Media, Conditioned; D006131:Growth Inhibitors; D018969:Insulin-Like Growth Factor Binding Proteins; D013002:Somatomedins; D004247:DNA