AZ3146 is a selective Mps1 inhibitor with IC50 of ~35 nM.

Mps1:35 nM

AZ3146不影响Aurora B和BubR1的有丝分裂特异性磷酸化形式。HeLa细胞用诺考达唑和2 μM AZ3146处理,仅短暂延迟有丝分裂,随后重新复制它们的基因组,表明AZ3146能够覆盖SAC。值得注意的是,90% AZ3146处理的HeLa细胞发生异常有丝分裂,~50%进入分裂后期的细胞没有调整它们的染色体,~30%完成有丝分裂的细胞没有进行明显的染色体分离。AZ3146也抑制FAK,JNK1,JNK2 和 Kit。AZ3146明显抑制细胞中Mps1的磷酸化作用。AZ3146也会抑制已经建立的SAC信号,如从诺考达唑阻断释放后,AZ3146明显加速有丝分裂结束。AZ3146对Mad2的着丝粒定位有显著影响,将其降至~15%,但是它对Mad1的作用不明显,其水平保持在~60%。进入有丝分裂期前,Mps1被AZ3146抑制,随后Mad1和Mad2对着丝粒的聚集被阻止。然而,如果Mps1在有丝分裂进入后被AZ3146抑制,则Mad1-C-Mad2核心复合物仍然与着丝粒结合,但O-Mad2不能聚集到核心。在其他未受到干扰的有丝分裂中,AZ3146使完成有丝分裂的时间从对照组的90分钟减少到32分钟。

His-tagged human Mps1Cat encoding amino acids 510-857 is generated. For kinase assays, 500 ng is added to buffer (25 mM Tris-HCl, pH 7.4, 100 mM NaCl, 50 μg/mL BSA, 0.1 mM EGTA, 0.1% β-mercaptoethanol, 10 mM MgCl2, and 0.5 μg/mL myelin basic protein), AZ3146, and 100 μM γ-[32P]ATP (2 μCi/assay). Reactions are incubated at 30°C for 20 min, spotted onto P81 paper, washed in 0.5% phosphoric acid, and immersed in acetone. Phosphate incorporation is determined by scintillation counting. For immunoprecipitation kinase assays, HeLa cells are treated with nocodazole for 14 h, mitotic cells isolated, washed in PBS, and lysed for 30 min in 50 mM Tris-HCl, pH 7.4, 100 mM NaCl, 0.5% NP-40, 5 mM EDTA, 5 mM EGTA, 40 mM β-glycerophosphate, 0.2 mM PMSF, 1 mM DTT, 1 mM sodium orthovanadate, 20 mM sodium fluoride, 1 μM okadaic acid, and complete EDTA-free protease inhibitor cocktail. Full-length Mps1 is immunoprecipitated. Purified complexes are washed with lysis buffer containing 100 mM NaCl and assayed as described for the recombinant protein. To quantify 32P incorporation, reactions are stopped with SDS sample buffer and separated by SDS-PAGE followed by phosphorimaging. The plate is analyzed using a phosphorimager using AIDA software. To assess the specificity of AZ3146, a single-point screen is carried using kinase profiling service. 50 kinases are selected and assayed with 1 μM AZ3146[1].

AZ3146 is disolved in DMSO (100 mM) and diluted into 100 μM, 10 μM, 1 μM and 0.1 μM sequentially with DMEM containing 10% FBS before use[2]. The TTK inhibitor AZ3146 is disolved in DMSO at a concentration in 100 mM and diluted into 100 μM, 10 μM, 1 μM and 0.1 μM sequentially with DMEM containing 10% FBS before use. In vitrocytotoxicity assays are performed. HCC cells are plated into 96-well plates at the density of 3×103 per well. AZ3146 is added in the indicated concentrations the next day. The inhibitor treated cells are cultured and tested at a 24-hour intervals for 3-4 days using CCK-8[2].