JNJ-7706621 is a potent aurora kinase inhibitor that also inhibits CDK1 and CDK2.

CDK2-CyclinA:4 nM, CDK2-CyclinE:3 nM, Aurora B:15 nM, Aurora A:11 nM, CDK1-CyclinB:9 nM

JNJ-7706621 (100 or 125 mg/kg) induced tumor regression in mice carrying human melanoma A375 xenografts.

JNJ-7706621 demonstrates varied potency across different cell types, exhibiting greater effectiveness in inhibiting the growth of normal cell types, including MRC-5, HASMC, HUVEC, and HMVEC, with IC50 values ranging from 3.67-5.42 μM. It shows high efficacy against CDK1 and 2, with IC50 values of 3-9 nM, and exerts inhibitory effects on a range of human cancer cell types, such as HeLa, HCT-116, SK-OV-3, PC3, DU145, A375, MDA-MB-231, MES-SA, and MES-SA/Dx5, with IC50 values between 112-514 nM, irrespective of p53, retinoblastoma, or P-glycoprotein status. JNJ-7706621 also inhibits CDK3, 4, and 6, with IC50 values of 58-253 nM, and targets Aurora-A and B kinases with IC50 values of 11 and 15 nM, respectively. Furthermore, it inhibits VEGF-R2, FGF-R2, and GSK3β, with IC50 values of 154-254 nM. In HeLa or U937 cells, JNJ-7706621 (0.5-3 μM) delays the exit from the G1 phase, induces cell arrest in the G2-M phase, triggers nuclear replication, activates apoptosis, and reduces colony formation.

In vitro kinase assay for CDK1 and Aurora kinases:CDK1 kinase activity is tested by the CDK1/cyclin B complex purified from baculovirus to phosphorylate a biotinylated peptide substrate containing the consensus phosphorylation site for histone H1, which is phosphorylated in vivo by CDK1. Inhibition of CDK1 activity is measured by observing a decreased amount of 33P-γ-ATP incorporation into the immobilized substrate in streptavidin-coated 96-well scintillating microplates. CDK1 enzyme is diluted in 50 mM Tris-HCl (pH 8), 10 mM MgCl2, 0.1 mM Na3VO4, 1 mM DTT, 1% DMSO, 0.25 μM peptide, 0.1 μCi per well 33P-γ-ATP, and 5 μM ATP in the presence or absence of various concentrations of JNJ-7706621 and incubated at 30 °C for 1 hour. The reaction is terminated by washing with PBS containing 100 mM EDTA and plates are counted in a scintillation counter. IC50 is determined by Linear regression analysis of the percent inhibition by JNJ-7706621.The Aurora kinase activity is measured with 10 μM ATP and a peptide containing a dual repeat of the kemptide phosphorylation motif.

Cell lines: HeLa,HCT-116,A375,SK-OV-3,MDA-MB-231 and PC-3 cells. Concentrations: 1 nM - 10 μM,dissolved in DMSO. Method: Measuring incorporation of 14C-labelled thymidine into newly synthesized DNA within the cells to determine the ability of JNJ-7706621 to inhibit the proliferation of cell growth.Cells are trypsinized and counted and 3-8 ×103 cells are added to each well of a 96-well CytoStar tissue culture treated scintillating microplate in 100 μL complete medium in a volume.Cells are incubated for 24 hours at 37 °C in an atmosphere containing 5% CO2.Next,1 μL JNJ-7706621 is added to the wells of the plate.Cells are incubated for another 24 hours.Methyl 14C-thymidine 56 mCi/mmol is diluted in complete medium and 0.2 μCi/well is added to each well of the CytoStar plate in a volume of 20 μL.The plate is incubated for 24 hours at 37 °C in JNJ-7706621 with 14C-thymidine.The contents of the plate are discarded and the plate is washed twice with 200 μL PBS.200 μL of PBS is added to each well.The top of the plate is sealed with a transparent plate sealer and a white plate backing sealer is applied to the bottom of the plate.The degree of methyl 14C-thymidine incorporation is quantified on a Packard Top Count.

Animal Models: Mouse xenograft model of A375 cellsFormulation & . Dosages: Dissolved in 0.5% methylcellulose containing 0.1% polysorbate 80 in sterile water.100 or 125 mg/kg. Administration: Orally or by intraperitoneal injection