02705nas a2200229   4500008004100000245014300041210006900184260001400253300001400267490000700281520193200288100002502220700002202245700002102267700002102288700002102309700002602330700002202356700003002378700001802408856004902426       2008                        eng d00aThe tyrosine kinase inhibitor cediranib blocks ligand-induced vascular endothelial growth factor receptor-3 activity and lymphangiogenesis0 atyrosine kinase inhibitor cediranib blocks ligandinduced vascula  c2008/Jun/  a4754 - 620 v683 aSolid tumors express a range of factors required to sustain their growth and promote their dissemination. Among these are vascular endothelial growth factor-A (VEGF-A), the key angiogenic stimulant, and VEGF-C, a primary mediator of lymphangiogenesis. Small molecule tyrosine kinase inhibitors offer the potential to inhibit more than one kinase and impede tumor growth by multiple mechanisms. However, their potency toward individual targets can vary. Cediranib (RECENTIN; AZD2171) is an inhibitor of VEGF signaling that has been shown in experimental models to prevent VEGF-A-induced angiogenesis and primary tumor growth, yet the effects of cediranib on VEGF receptor (VEGFR)-3-mediated endothelial cell function and lymphangiogenesis are unknown. To better understand the activity of cediranib against VEGFR-3 and its associated signaling events compared with its activity against VEGFR-2, we used the receptor-specific ligands VEGF-E and VEGF-C156S. In human endothelial cells, cediranib inhibited VEGF-E-induced phosphorylation of VEGFR-2 and VEGF-C156S-induced phosphorylation of VEGFR-3 at concentrations of </=1nmol/L and inhibited activation of downstream signaling molecules. Additionally, cediranib blocked VEGF-C156S-induced and VEGF-E-induced proliferation, survival, and migration of lymphatic and blood vascular endothelial cells. In vivo, cediranib (6 mg/kg/d) prevented angiogenesis and lymphangiogenesis induced by VEGF-E-expressing and VEGF-C156S-expressing adenoviruses, respectively. Cediranib (6 mg/kg/day) also blocked angiogenesis and lymphangiogenesis induced by adenoviruses expressing VEGF-A or VEGF-C and compromised the blood and lymphatic vasculatures of VEGF-C-expressing tumors. Cediranib may, therefore, be an effective means of preventing tumor progression, not only by inhibiting VEGFR-2 activity and angiogenesis, but also by concomitantly inhibiting VEGFR-3 activity and lymphangiogenesis.1 aHeckman, Caroline, A1 aHolopainen, Tanja1 aWirzenius, Maria1 aKeskitalo, Salla1 aJeltsch, Michael1 aYlä-Herttuala, Seppo1 aWedge, Stephen, R1 aJürgensmeier, Juliane, M1 aAlitalo, Kari  uhttp://view.ncbi.nlm.nih.gov/pubmed/1855952202580nas a2200097   4500008004100000245013000041210006900171260007100240520211900311856005202430       2007                        eng d00aInhibiton of VEGF-C-induced VEGFR-3 activity and lymphatic endothelial cell function by the tyrosine kinase inhibitor AZD21710 aInhibiton of VEGFCinduced VEGFR3 activity and lymphatic endothel  aLos Angeles, CAbAmerican Association for Cancer Researchc2007///3 aSolid tumors express a range of growth factors required to sustain their growth and promote their dissemination. Among these factors is vascular endothelial growth factor-A (VEGF-A), the key angiogenic stimulant, and VEGF-C, a primary mediator of lymphangiogenesis. Small molecule tyrosine kinase inhibitors can prevent VEGF signaling activity by targeting the VEGF receptors and are an effective approach to impede tumor progression. The indole-ether quinazoline AZD2171 is a highly potent ATP-competitive inhibitor of VEGFR-2 (KDR) kinase, with additional activity against VEGFR-1 (Flt-1) and -3 (Flt-4), that has been shown in experimental models to prevent VEGF-A-induced angiogenesis and primary tumor growth (Wedge et al. Cancer Res 2005;65:4389-4400). For these studies we wished to further assess the ability of AZD2171 to inhibit VEGFR-3 and its associated functions. Upon binding its ligands VEGF-C or -D, VEGFR-3 becomes activated with the resulting signaling cascade eventually translated into increased proliferation, survival and migration of lymphatic and blood vascular endothelial cells. At concentrations of ≤1 nM AZD2171 inhibited VEGFR-3 phosphorylation in porcine aortic endothelial cells selectively expressing the human receptor, and in human dermal microvascular endothelial cells (HDMVECs). In HDMVECs, AZD2171 prevented phosphorylation of signaling molecules downstream of VEGFR-2 and -3, ERK1/2, Akt and CREB, induced by the VEGFR-2 and -3-specific ligands VEGF-E and -C156S, respectively. Additionally, AZD2171 blocked VEGF-E- and -C156S-induced proliferation of both lymphatic and blood vascular endothelial cells at similar concentrations, and prevented ligand-induced endothelial cell cord formation in a Matrigel assay. The effects of AZD2171 on VEGF-C-induced lymphangiogenesis are currently being assessed in vivo. These studies, together with previous results, not only demonstrate that AZD2171 may be an effective means of preventing tumor progression by inhibition of VEGFR-2 activity and angiogenesis, but may also prevent further tumor spread by inhibiting VEGFR-3 activity  uhttp://dx.doi.org/10.1158/0008-5472.CAN-07-5809