The fibroblast growth factor receptors (FGFRs) are cell surface receptors with intrinsic tyrosine kinase activity, which is necessary for receptor activation and signal propagation. PD 173074 is a potent and selective inhibitor of FGFR tyrosine kinase activity, blocking autophosphorylation of FGFR1 with an IC50 value of 21.5 nM. For comparison, it weakly inhibits PDGFR and c-Src (IC50 = 17.6 and 19.8 μM, respectively) and has no effect on EGFR, InsR, MEK, or PKC. PD 173074 also prevents signaling, at nanomolar levels, through FGFR2-5. Inhibition of FGFR signaling using PD 173074, impairs angiogenesis as well as self-renewal of stem cells via ERK1/2 activation.
