TGF-BETA-1 INHIBITS THE CELL-PROLIFERATION STIMULATED BY IGF-I BY BLOCKING THE TYROSINE PHOSPHORYLATION OF 175KDA SUBSTRATE

Authors
LIU G TAKANO T AMINO N
Citation
G. Liu et al., TGF-BETA-1 INHIBITS THE CELL-PROLIFERATION STIMULATED BY IGF-I BY BLOCKING THE TYROSINE PHOSPHORYLATION OF 175KDA SUBSTRATE, Endocrine research, 22(3), 1996, pp. 277-287
Citations number
13
Categorie Soggetti
Endocrynology & Metabolism
Journal title
Endocrine research → ACNP
ISSN journal
07435800
Volume
22
Issue
3
Year of publication
1996
Pages
277 - 287
Database
ISI
SICI code
0743-5800(1996)22:3<277:TITCSB>2.0.ZU;2-#
Abstract
TGF-beta strongly inhibits the mitogenic effect of growth factors such as insulin-like growth-I (IGF-I) on thyroid follicular cells. To stud y the mechanism of this inhibiting action, the effect of TGF-beta 1 on tyrosine phosphorylation of 175kDa substrate induced by IGF-I was inv estigated in FRTL-5 thyroid epithelial cells. After treatment with TGF -beta 1, tyrosine phosphorylation of 175kDa protein induced by IGF-I w as inhibited in parallel with the degree of the inhibition of cell pro liferation. However, TGF-beta 1 had no effect on tyrosine phosphorylat ion of 120kDa substrate. These results suggest that TGF-beta 1 blocks the mitogenic signal of IGF-I by inhibiting the tyrosine phosphorylati on of 175kDa substrate in FRTL-5 cells.