4-arylazo-3,5-diamino-1H-pyrazole CDK inhibitors:: SAR study, crystal structure in complex with CDK2, selectivity, and cellular effects
4-arylazo-3,5-diamino-1H-pyrazole CDK inhibitors:: SAR study, crystal structure in complex with CDK2, selectivity, and cellular effects
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DOI：
10.1021/jm0605740
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发表时间：
2006-11-02
影响因子：
7.3
通讯作者：
Strnad, Miroslav
中科院分区：
文献类型：
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作者：
Krystof, Vladimir;Cankar, Petr;Strnad, Miroslav
在我们的小分子化合物集合的常规筛选中，我们最近鉴定了4-芳基偶氮-3，5-二氨基-1H-吡唑类作为一组新的ATP拮抗剂，对CDK 2-细胞周期蛋白E具有中等效力。基于35个类似物的初步SAR研究提出了药效团可以进一步优化的方法，例如，通过4-芳基环中的取代。酶动力学研究与铅化合物和X-射线晶体学的一个通道-CDK 2复合物表明，它的抑制模式是竞争性的。功能性激酶测定证实了对CDK的选择性，优先选择CDK 9细胞周期蛋白T1。在抗增殖试验中，最有效的抑制剂4-[（3，5-二氨基-1H-吡唑-4-基）二氮烯基]苯酚31 b（CAN 508）可降低癌细胞系HT-29的S期细胞频率。进一步观察到的细胞效应包括视网膜母细胞瘤蛋白和RNA聚合酶II的C-末端结构域的磷酸化降低、mRNA合成的抑制和肿瘤抑制蛋白p53的诱导，所有这些都与CDK 9的抑制一致。
In a routine screening of our small-molecule compound collection we recently identified 4-arylazo-3,5-diamino-1H-pyrazoles as a novel group of ATP antagonists with moderate potency against CDK2-cyclin E. A preliminary SAR study based on 35 analogues suggests ways in which the pharmacophore could be further optimized, for example, via substitutions in the 4-aryl ring. Enzyme kinetics studies with the lead compound and X-ray crystallography of an inhibitor-CDK2 complex demonstrated that its mode of inhibition is competitive. Functional kinase assays confirmed the selectivity toward CDKs, with a preference for CDK9cyclin T1. The most potent inhibitor, 4-[(3,5-diamino-1H-pyrazol-4-yl) diazenyl] phenol 31b (CAN508), reduced the frequency of S-phase cells of the cancer cell line HT-29 in antiproliferation assays. Further observed cellular effects included decreased phosphorylation of the retinoblastoma protein and the C-terminal domain of RNA polymerase II, inhibition of mRNA synthesis, and induction of the tumor suppressor protein p53, all of which are consistent with inhibition of CDK9.