In vitro activity: Cediranib (also called AZD2171, an indole ether quinazoline derivative) is a highly potent VEGFR (KDR) inhibitor with IC50 of<1 nM and is>1000-fold more selective for VEGFR than PDGFR-α, CSF-1R and Flt3 in HUVEC cells. Inhibition of vascular endothelial growth factor-A (VEGF) signaling is a promising therapeutic approach that aims to stabilize the progression of solid malignancies by abrogating tumor-induced angiogenesis. By competing with adenosine triphosphate, cediranib binds to and inhibits all three vascular endothelial growth factor receptor (VEGF-1,-2,-3) tyrosine kinases, thereby blocking VEGF-signaling, angiogenesis, and tumor cell growth. Cediranib is being developed clinically as a once-daily oral therapy for the treatment of cancer. Cediranib (also called AZD2171, an indole ether quinazoline derivative) is a highly potent VEGFR (KDR) inhibitor with IC50 of<1 nm and is>1000-fold selective more for VEGFR than PDGFR-α, CSF-1R and Flt3 in HUVEC cells. Inhibition of vascular endothelial growth factor-A (VEGF) signaling is a promising therapeutic approach that aims to stabilize the progression of solid malignancies by abrogating tumor-induced angiogenesis. By competing with adenosine triphosphate, cediranib binds to and inhibits all three vascular endothelial growth factor receptor (VEGF-1,-2,-3) tyrosine kinases, thereby blocking VEGF-signaling, angiogenesis, and tumor cell growth. Cediranib is being developed clinically as a once-daily oral therapy for the treatment of cancer.

Kinase Assay: Cediranib is dissolved in DMSO at a concentration of 10 mM. All enzyme assays are run at, or just below, the respective Km for ATP (0.2 - 30 μM). The inhibitory activity of Cediranib is determined against a range of recombinant tyrosine kinases [KDR, Flt-1, Flt-4, c-Kit, PDGFRα, PDGFRβ, CSF-1R, Flt-3, FGFR1, Src, Abl, epidermal growth factor receptor (EGFR), ErbB2, Aurora A, and Aurora B] using ELISA. Selectivity versus CDK2 and CDK4 serine/threonine kinases is examined using scintillation proximity assays with a retinoblastoma substrate and [γ-sup>33P]ATP. Activity of Cediranib is compared to MAPK kinase (MEK), which shows dual specificity. It is determined using a MAPK substrate, [γ-33P]ATP, and paper capture/scintillation counting.

Cell Assay: The proliferation of the HUVEC cell line is evaluated in the presence and absence of growth factors by measuring 3H-thymidine incorporation following a 4-day incubation period. Proliferation of MG63 osteosarcoma cells is induced by PDGF-AA, which selectively activates signaling of the PDGFRα homodimer. HUVEC and MG63 osteosarcoma cells are cultured in DMEM without phenol red containing 1% charcoal stripped FCS, 2 mM glutamine, and 1% nonessential amino acids for 24 hours. Cediranib or vehicle is added with PDGF-AA ligand (50 ng/mL) and plates incubated for another 72 hours. Cellular proliferation is determined using bromodeoxyuridine ELISA.