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Research Area
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Description
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Cancer |
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Biological Activity
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Description
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CYC116 is a potent inhibitor of Aurora A and Aurora B with Ki of 8.0 nM and 9.2 nM, respectively. |
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Targets
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Aurora A |
Aurora B |
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IC50 |
8.0 nM (Ki) |
9.2 nM (Ki) [1] |
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In Vitro
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The most Aurora-selective CYC116 shows inhibitory effect on Aurora A and B kinases 50-fold more potently than any of the CDKs assayed. [1] CYC116 is initially screened against a panel of human leukemia and solid tumor cell lines using an MTT antiproliferative assay. The results show that CYC116 has broad-spectrum antitumor activity and shows specific cytotoxicity against the acute myelogenous leukemia cell line MV4-11 with IC50 of 34 nM. [1] In addition, anti-proliferative activity of CYC116 is found to be associated with Aurora A and B modulation such as, inhibition of Aurora autophosphorylation, reduction of histone H3 phosphorylation, polyploidy, followed by cell death, resulting from a failure in cytokinesis. [1] |
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In Vivo
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Mice bearing subcutaneous NCI-H460 xenografts are given CYC116 orally for 5 days, at dose levels of 75 and 100 mg/kg q.d. It leads to tumor growth delays of 2.3 and 5.8 days, which translated into specific growth delays of 0.32 and 0.81, respectively. [1] |
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Clinical Trials
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CYC116 is currently being investigated in Phase I clinical trials in patients with advanced solid tumors. |
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Features
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CYC116 is an orally bioavailable, small molecule; an inhibitor of Aurora kinase/VEGFR2. |
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Protocol
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Kinase Assay
[1]
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| Kinase Assays |
Aurora A kinase assays are performed using a 25 μL reaction volume (25 mM β-glycerophosphate, 20 mM Tris/HCl, pH 7.5, 5 mM EGTA, 1 mM DTT, 1 mM Na3VO4, 10 μg of kemptide (peptide substrate)). Recombinant Aurora A kinase is diluted in 20 mM Tris/HCl, pH 8, containing 0.5 mg/mL BSA, 2.5% glycerol, and 0.006% Brij-35. Reactions are started by the addition of 5 μL Mg/ATP mix (15 mM MgCl2, 100 μM ATP, with 18.5 kBq γ-32P-ATP per well) and incubated at 30°C for 30 minutes before termination with 25 μL of 75 mM H3PO4. Aurora B kinase assays are performed like Aurora A except that prior to use, Aurora B is activated in a separate reaction at 30°C for 60 minutes with inner centromere protein. |
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Cell Assay
[1]
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| Cell Lines |
HeLa, MCF7, MV4-11 and A2780 cells |
| Concentrations |
0-10 μM |
| Incubation Time |
72 or 96 hours |
| Methods |
Standard MTT assays are performed. In short, cells are seeded into 96-well plates according to doubling time and incubated overnight at 37°C. Test compounds are made up in DMSO, a 3-fold dilution series is prepared in 100 μL of cell medium, added to cells (in triplicates) and incubated for 72 or 96 hours at 37°C. MTT is made up as a stock of 5 mg/mL in cell medium, and the solution is filter-sterilized. Medium is removed from the cells followed by a wash with PBS. MTT solution is then added at 20 μL/well and incubated in the dark at 37°C for 4 hours. MTT solution is removed and cells are again washed with 200 μL of PBS. MTT dye is solubilized with 200 μL/well of DMSO by agitation. Absorbance is read at 540 nm and data analyzed using curve-fitting software to determine IC50 values. |
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Animal Study
[1]
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| Animal Models |
NCI-H460 cells are implanted intraperitoneally into the mice. |
| Formulation |
CYC116 is dissolved in DMSO and then diluted in water. |
| Doses |
75 and 100 mg/kg |
| Administration |
Administered via p.o. |
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