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Research Area
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Description
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Solid tumours,Ovarian cancer |
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Biological Activity
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Description
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ON-01910 (Estybon, Novonex, Rigosertib) is a non-ATP-competitive inhibitor of PLK1 (Polo-like kinase 1) with IC50 of 9 nM. |
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Targets
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PLK1 |
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IC50 |
9 nM [1] |
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In Vitro
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ON-01910 is non-ATP-competitive inhibitor to PLK1 with IC50 of 9 nM. ON-01910 also exhibits inhibition against PLK2, PDGFR, Flt1, BCR-ABL, Fyn, Src, and CDK1, with IC50 of 18–260 nM. ON-01910 shows cell killing activity against 94 different tumor cell lines with IC50 of 50–250 nM, including BT27, MCF-7, DU145, PC3, U87, A549, H187, RF1, HCT15, SW480, and KB cells. While in normal cells, such as HFL, PrEC, HMEC, and HUVEC, ON-01910 has little or no effect unless its concentration is greater than 5–10 μM. In HeLa cells, ON-01910 (100–250 nM) induces spindle abnormalities and apoptosis. [1] ON-01910 also inhibits several multidrug resistant tumor cell lines, including MES-SA, MES-SA/DX5a, CEM, and CEM/C2a, with IC50 of 50–100 nM. In DU145 cells, ON-01910 (0.25–5 μM) blocks cell cycle progression in G2/M phase, results in an accumulation of cells containing subG1 content of DNA, and activates apoptotic pathways. In A549 cells, ON-01910 (50 nM–0.5 μM) induces loss of viability and caspase 3/7 activation. [2] In a recent study, ON-01910 induces apoptosis in chronic lymphocytic leukemia (CLL) cells without toxicity against T-cells or normal B-cells. ON-01910 also abrogates the pro-survival effect of follicular dendritic cells on CLL cells and reduces SDF-1-induced migration of leukemic cells. [3] |
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In Vivo
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In mouse xenograft models of Bel-7402, MCF-7, and MIA-PaCa cells, ON-01910 (250 mg/kg) markedly inhibits tumor growth. [1] ON-01910 (200 mg/kg) shows inhibition on tumor growth in a mouse xengraft model of BT20 cells. [2] |
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Clinical Trials
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ON-01910 is currently under a Phase III clinical trial in refractory myelodysplastic syndrome patients with excess blasts. |
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Features
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Protocol
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Kinase Assay
[1]
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| In vitro enzyme assays for PLK1 |
Recombinant PLK1 (10 ng) is incubated with different concentrations of ON-01910 in a 15 μL reaction mixture (50 mM HEPES, 10 mM MgCl2, 1 mM EDTA, 2 mM Dithiothreitol, 0.01% NP-40 [pH 7.5]) for 30 min at room temperature. Kinase reactions are performed for 20 min at 30 °C in a volume of 20 μL (15 μL enzyme + inhibitor, 2 μL 1 mM ATP), 2 μL of γ32P-ATP (40 μCi), and 1 μL of recombinant Cdc25C (100 ng) or casein (1 μg) substrates. Reactions are terminated by boiling for 2 min in 20 μL of 2× Laemmli buffer. Phosphorylated substrates are separated by 18% SDS-PAGE. The gels are dried and exposed to X-ray film for 3–10 min. |
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Cell Assay
[2]
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| Cell Lines |
A number of tumor cell lines, including BT20, MCF-7, DU145, PC3, U87, A549, H187, RF1, HCT15, HeLa, and Raji cells |
| Concentrations |
1 nM - 10 μM, dissolved in DMSO as stock solution. |
| Incubation Time |
96 hours |
| Methods |
Cells are grown in either DMEM or RPMI supplemented with 10% fetal bovine serum and 1 unit/mL penicillin–streptomycin solution. Tumor cells are plated into six-well dishes at a density of 1 × 105cells/mL/well, and ON-01910 is added 24 hours later at various concentrations. Cell counts are determined from duplicate wells after 96-hour of treatment. The total number of viable cells is determined by trypan blue exclusion. |
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Animal Study
[1]
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| Animal Models |
Mouse (female athymic, NCR-nu/nu) xenograft models of Bel-7402, MCF-7, and MIA-PaCa cells |
| Formulation |
Dissolved in PBS |
| Doses |
250 mg/kg |
| Administration |
Intraperitonially |
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References |
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[1] Gumireddy K, et al. Cancer Cell, 2005, 7(3), 275-286.
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[2] Reddy MV, et al. J Med Chem, 2011, 54(18), 6254-6276.
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[3] Chapman CM, et al. Clin Cancer Res, 2012 18(7), 1979-1991.
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