Crystal structure of an angiogenesis inhibitor bound to the FGF receptor tyrosine kinase domain

Abstract

Angiogenesis, the sprouting of new blood vessels from pre-existing ones, is an essential physiological process in development, yet also plays a major role in the progression of human diseases such as diabetic retinopathy, atherosclerosis and cancer. The effects of the most potent angiogenic factors, vascular endothelial growth factor (VEGF), angiopoietin and fibroblast growth factor (FGF) are mediated through cell surface receptors that possess intrinsic protein tyrosine kinase activity. In this report, we describe a synthetic compound of the pyrido[2,3-d]pyrimidine class, designated PD 173074, that selectively inhibits the tyrosine kinase activities of the FGF and VEGF receptors. We show that systemic administration of PD 173074 in mice can effectively block angiogenesis induced by either FGF or VEGF with no apparent toxicity. To elucidate the determinants of selectivity, we have determined the crystal structure of PD 173074 in complex with the tyrosine kinase domain of FGF receptor 1 at 2.5 Å resolution. A high degree of surface complementarity between PD 173074 and the hydrophobic, ATP-binding pocket of FGF receptor 1 underlies the potency and selectivity of this inhibitor. PD 173074 is thus a promising candidate for a therapeutic angiogenesis inhibitor to be used in the treatment of cancer and other diseases whose progression is dependent upon new blood vessel formation.

Conditional activation of FGFR1 in the prostate epithelium induces angiogenesis with concomitant differential regulation of Ang-1 and Ang-2

“…Interestingly, in the absence of exogenous bFGF, expression of HA-FGFR1 alone caused a 1.7-fold (1.770.2; Po0.04) increase in Ang-2 promoter activity, which we attribute to residual receptor activity following serum starvation (panel d). To confirm that Ang-2 promoter activity was truly dependent on FGFR1 activity, cells expressing HA-FGFR1 were treated with PD173074, a specific inhibitor of FGF receptor activity (Mohammadi et al, 1998). Treatment with PD173074 inhibited tyrosine phosphorylation of HA-FGFR1 independent of exogenous bFGF (panel d) and caused Ang-2 promoter activity to return to baseline levels (panel e).…”

Fibroblast growth factor 2 regulates endothelial cell sensitivity to sunitinib

“…The small molecule tyrosine kinase inhibitor PD173074 is a potent inhibitor of FGF receptor tyrosine kinase activity (Mohammadi et al, 1998;Pardo et al, 2009). We tested the relative ability of sunitinib and PD173074 to inhibit VEGF-and FGF2-mediated endothelial cell proliferation.…”

Discovery of Substituted 1H-Pyrazolo[3,4-b]pyridine Derivatives as Potent and Selective FGFR Kinase Inhibitors

“…PD173074 (Figure 1), the first reported selective FGFR inhibitor, inhibits FGFR1 with an IC 50 value of 21.5 nM at the molecular level, while inhibiting PDGFR, c-Src and EGFR, as well as several serine/threonine kinases with 1000-fold or greater IC 50 values. 17 Nevertheless, PD173074 exhibits submicromolar inhibitory activity at the cellular level against VEGFR2 (IC 50 = 100−200 nM). 17 The crystal structure of PD173074 in complex with the FGFR1 kinase domain elucidates that its high affinity and selectivity for FGFR1 stem from the presence of 3,5-dimethoxy phenyl ring that adopts an almost perpendicular orientation to the plane of the pyrido[2,3-d]pyrimidine rings and fills optimally a complementary hydrophobic pocket.…”

“…17 Nevertheless, PD173074 exhibits submicromolar inhibitory activity at the cellular level against VEGFR2 (IC 50 = 100−200 nM). 17 The crystal structure of PD173074 in complex with the FGFR1 kinase domain elucidates that its high affinity and selectivity for FGFR1 stem from the presence of 3,5-dimethoxy phenyl ring that adopts an almost perpendicular orientation to the plane of the …”