GSK1070916

507, 63

Mice tumor xenograft models (A549, SW620, HCT116, H460, MCF-7, HL60, K562, Colo205)

GSK1070916A is under a Phase I Trial to study the side effects and best dose of it in treating patients with advanced solid tumors.

25, 50, or 100 mg/kg

3.5 nM, 3.5 nM, 3.5 nM, 3.5 nM, 3.5 nM, 3.5 nM

GSK1070916 (25, 50, or 100 mg/kg) shows dose-dependent inhibition of phosphorylation of an Aurora B–specific substrate in mice and consistent with its broad cellular activity, has antitumor effects in 10 human tumor xenograft models including breast, colon, lung, and two leukemia models. [2]

Kinase Assay, The ability of GSK1070916 to inhibit the Aurora enzymes is measured using in vivo kinase assays. The assays measure the ability of Aurora A, Aurora B and Aurora C to phosphorylate a synthetic peptide substrate. Biotin-Ahx-RARRRLSFFFFAKKK-NH2 is used for the Aurora A–TPX2 LEADseekerTM assay and 5FAM-PKAtide is used for the IMAPTM assay for all three Aurora kinases. To take into account time-dependent inhibition of Aurora enzymes, Aurora A–TPX2, Aurora B–INCENP and Aurora C–INCENP are incubated with GSK1070916 at various concentrations for 30 min before the reactions are initiated with the addition of substrates. For the Aurora A LEADseekerTM assay, final assay conditions are 0.5 nM Aurora A–TPX2, 1 uM peptide substrate, 6 mM MgCl2, 1.5 uM ATP, 0.003 uCi/uL [gamma-33P] ATP in 50 mM Hepes, pH 7.2, 0.15 mg/mL BSA, 0.01% Tween-20, 5 mM DTT and 25 mM KCl. The reactions are incubated at room temperature (25 C) for 120 min and terminated by the addition of LEADseekerTM beads in PBS containinnal concentration 2 mg/mL beads and 25 mM EDTA). The plates are then sealed, and the beads are allowed to settle overnight. Product formation is quantified using a Viewlux Imager. For the IMAPTM assays, Aurora A–TPX2 (final concentration 1 nM), Aurora B–INCENP (final concentration 2 nM) or Aurora C–INCENP (final concentration 2.5 nM) is added to the compound-containing plates in 5 uL of buffer (25 mM Hepes, pH 7.2, for Aurora A, 25 mM Hepes, pH 7.5, for Aurora B and 20 mM Hepes, pH 7.2, for Aurora C) containing 0.15 mg/mL BSA, 0.01% Tween 20 and 25 mM NaCl. This mixture is incubated at room temperature for 30 min. To start the reaction, 5 uL of a substrate solution is added containing the same Hepes buffer as used for the pre-incubation, 25 mM NaCl, MgCl2 (2, 4 and 4 mM for Aurora A, B and C respectively), DTT (4, 4 and 2 mM for Aurora A, B and C respectively), ATP (4, 4 and 10 uM for Aurora A, B and C respectively), 200 nM 5FAM-PKAtide, 0.01% Tween 20 and 0.15 mg/mL BSA. The reactions are incubated at emperature for 120 min for Aurora A and B and 60 min for Aurora C. These reactions are then terminated by the addition of 10 uL of 1:500 (1:600 for Aurora C) Progressive Binding Reagent in 95% Progressive Binding Buffer A and 5% Progressive Binding Buffer B. Plates are incubated at room temperature for approx. 90–120 min (time allowed for equilibrium to be reached). Plates are read in a Molecular Devices Analyst plate reader in fluorescence polarization mode.

DMSO 102 mg/mL, Water <1 mg/mL, Ethanol 102 mg/mL

3-(4-(4-(2-(3-((dimethylamino)methyl)phenyl)-1H-pyrrolo[2, 3-b]pyridin-4-yl)-1-ethyl-1H-pyrazol-3-yl)phenyl)-1, 1-dimethylurea