Onvansertib (NMS-1286937) is a PLK1 inhibitor (IC50=2 nM) with high selectivity and oral activity. Onvansertib has antitumor activity and inhibits tumor growth.

PLK1:2 nM

方法: 137 个肿瘤细胞用 Onvansertib 处理 72 h，使用 CellTiter-Glo Assay 检测细胞活力。
结果: 137 个细胞系中的 60 个细胞系的 IC50 值低于 100 nmol/L，只有 9 个细胞系的 IC50 值高于 1 µmol/L，表明活性范围广泛。[1]
方法: Cisplatin 敏感和耐药的 CAL33 细胞用 Onvansertib (25-50 nM) 处理 24 天，使用 Flow cytometry 检测细胞周期。
结果: Onvansertib 治疗以剂量依赖的方式诱导 G2/M 期所有敏感和耐药 CAL33 细胞的积累。[2]

方法: 为检测体内抗肿瘤活性，将 Onvansertib (60 mg/kg) 口服给药给携带 HCT116 异种移植物的 Hsd, athymic nu/nu 小鼠，每天一次，持续八天。
结果: Onvansertib 能在最小的体重减轻的情况下获得良好的抗肿瘤活性，在相当程度上抑制了肿瘤生长，TGI 为 79%。[1]

Kinase profile: The inhibitory activity of putative kinase inhibitors and the potency of selected compounds are determined using a trans-phosphorylation assay. Specific peptide or protein substrates are trans-phosphorylated by their specific serine-threonine or tyrosine kinase, in the presence of ATP traced with 33P-γ-ATP, at optimized buffer and cofactors conditions. At the end of the phosphorylation reaction, more than 98% unlabeled ATP and radioactive ATP is captured by adding an excess of the ion exchange dowex resin; the resin then settles down to the bottom of the reaction plate by gravity. Supernatant, containing the phosphorylated substrate, is subsequently withdrawn and transferred into a counting plate, followed by evaluation by b-counting. Inhibitory potency evaluation for all the tested kinases was performed at 25 °C using a 60 min end-point assay where the concentrations of ATP and substrates are kept equal to 2 x αKm and saturated (>5 x αKm), respectively.

Cells are seeded into 96- or 384-well plates at densities ranging from 10,000 to 30,000/cm2 for adherent and 100,000/mL for nonadherent cells in appropriate medium supplemented with 10% fetal calf serum. After 24 hours, cells were treated in duplicate with serial dilutions of NMS-P937, and 72 hours later, the viable cell number was assessed by the CellTiter-Glo Assay (Promega). IC50 values were calculated with a sigmoidal fitting algorithm (Assay Explorer MDL). Experiments were carried out independently at least twice.(Only for Reference)