OTSSP167 (OTS167) is an orally available inhibitor of maternal embryonic leucine zipper kinase (MELK) with potential antineoplastic activity.

MELK:0.41 nM

在MDA-MB-231模型中,每天一次口服10 mg/kg OTSSP167显示对TGI 72％的生长抑制率.OTSSP167以静脉内和口服两种方式处理小鼠,异种移植研究中显示出对乳房、肺、前列腺和胰腺癌细胞系的显著肿瘤生长抑制作用.OTSSP167作用于多种癌症类型,具有剂量依赖性及MELK依赖性,对体重减轻没有或很少有影响.

OTSSP167抑制PSMA1和DBNL的磷酸化,PSMA1和DBNL是新型MELK底物,对干细胞的特征和侵袭性是至关重要的。OTSSP167通过抑制PSMA1磷酸化抑制乳腺癌细胞的球形成。OTSSP167抑制MELK高水平表达的A549、T47D、DU4475和22Rv1 癌细胞,IC50分别为6.7,4.3,2.3和6.0 nM。

in vitro kinase assay: MELK recombinant protein (0.4 μg) is mixed with 5 μg of each substrate in 20 μL of kinase buffer containing 30 mM Tris-HCl (pH), 10 mM DTT, 40 mM NaF, 10 mM MgCl2, 0.1 mM EGTA with 50 μM cold-ATP and 10 Ci of [γ-32P]ATP for 30 min at 30 °C. The reaction is terminated by addition of SDS sample buffer and boiled for 5 min prior to SDS-PAGE. The gel is dried and autoradiographed with intensifying screens at room temperature. OTSSP167 (final concentration of 10 nM) is dissolved in DMSO and added to kinase buffer before the incubation.

Cell Counting Kit-8(Only for Reference)