Jr. Hawker et Hj. Granger, TYROSINE KINASE INHIBITORS IMPAIR FIBROBLAST GROWTH-FACTOR SIGNALING IN CORONARY ENDOTHELIAL-CELLS, The American journal of physiology, 266(1), 1994, pp. 80000107-80000120
We examined the effect of various tyrosine kinase inhibitors on basic
fibroblast growth factor (bFGF)-induced cell signaling and DNA synthes
is in coronary venular endothelial cells (CVEC). Two tyrosine kinase i
nhibitors, genistein and methyl 2,5-dihydroxycinnamate, showed reversi
ble, dose-dependent inhibition of bFGF-stimulated DNA synthesis in CVE
C with half-maximal inhibitory concentrations of 12 and 3 mu M, respec
tively. Both compounds exhibited preferential inhibition of bFGF vs. s
erum-induced DNA synthesis. bFGF stimulated increased tyrosine phospho
rylation of CVEC cellular proteins, including the FGF receptor, which
were visible within 1 min of treatment. Concomitant with their effect
on DNA synthesis, both compounds exhibited dose-dependent inhibition o
f tyrosine phosphorylation of intracellular substrates induced by bFGF
. A 2-h pretreatment of quiescent CVEC with genistein blocked nuclear
translocation but not cytoplasmic internalization of bFGF, whereas the
same treatment with methyl 2,5-dihydroxycinnamate inhibited both proc
esses. These results suggest that activation of bFGF receptor tyrosine
kinase activity plays a role in nuclear translocation of bFGF and ini
tiation of DNA synthesis in endothelial cells.