Development of small molecule inhibitors of protein kinase D

描述（由申请人提供）：蛋白激酶D（PKD）是一个新的关键第二信使甘油二酯靶点家族，可被G蛋白偶联受体激动剂和生长因子激活。PKD家族-PKD 1，2和3 -在许多基本细胞过程中起重要作用。PKD的失调与多种病理状况和癌症有关。然而，PKD特异性抑制剂的缺乏严重阻碍了我们理解PKD特异性信号通路和生物学功能以及在人类疾病中靶向PKD的能力。我们最近报道了PKD的第一个有效和选择性的小分子抑制剂：benzoxoloazepinolone CID 755673，通过对196，173种化合物的高通量筛选活动鉴定。CID 755673是一种具有亚微摩尔效力的泛PKD抑制剂。它具有细胞活性，阻断PKD的已知生物学作用，并抑制前列腺癌细胞的增殖、迁移和侵袭的癌症相关特性。重要的是，这种抑制剂不与ATP竞争酶抑制，并且与至少20种不同的激酶（包括CAMK II 1、AKT、PKA和几种PKC亚型）相比，对PKD具有高度选择性。最关键的是，CID 755673的结构优化产生了一种新型苯并噻吩衍生物kb-NB 142 -70，其具有低纳摩尔效力和对PKD的更大选择性。我们假设CID 755673可以优化为一类新型PKD抑制剂，其具有有效和选择性阻断PKD功能的独特作用机制。我们的长期目标是建立一种系统的方法来开发CID 755673衍生的探针分子作为创新的PKD抑制剂。我们提出的研究策略集中在铅优化，机制评估和体内疗效评估的CID 755673及其类似物。提出了三个具体的目标，代表了第一个主要的努力，朝着发展的有效和选择性的药物消融剂PKD：目的1。通过结构修饰优化CID 755673，以获得更有效和选择性的衍生物。目标2.确定CID 755673及其类似物对PKD的精确选择性的分子机制。目标3.检验CID 755673及其衍生物在体内引起PKD功能的强效和选择性阻断的假设。 公共卫生相关性：蛋白激酶D家族是关键的第二信使甘油二酯的新型受体，并且是癌症和其它疾病的新兴治疗靶点。进一步了解PKD在生物过程中的作用并在人类疾病中靶向它，由于缺乏可以容易地应用于细胞和动物的PKD特异性抑制剂而受到严重阻碍。我们最近发现了PKD的第一个有效的和选择性的细胞活性小分子抑制剂-CID 755673。我们假设CID 755673可以被优化以产生一类新型PKD抑制剂，其具有有效和选择性阻断PKD功能的独特作用机制。拟议的研究重点是这些新的化学实体的铅优化，机制评价和体内疗效评估。该研究的成功完成将导致一类新的PKD抑制剂，可用作解剖细胞和动物中PKD介导的信号通路和功能的强大工具。这也将提供潜在的未来临床开发的化合物作为新的抗肿瘤药物的基础。

DESCRIPTION (provided by applicant): Protein kinase D (PKD) is a novel family of the key second messenger diacylglycerol targets that can be activated by G-protein coupled receptor agonists and growth factors. The family of PKD - PKD1, 2 and 3 - plays important roles in many fundamental cellular processes. Deregulation of PKD has been implicated in multiple pathological conditions and cancer. However, the lack of a PKD-specific inhibitor has severely impeded our ability to understand PKD-specific signaling pathways and biological functions and to target it in human diseases. We have recently reported the first potent and selective small molecule inhibitor for PKD: benzoxoloazepinolone CID755673 that was identified through a high throughput screening campaign of 196,173 compounds. CID755673 is a pan-PKD inhibitor with submicromolar potencies. It was cell active and blocked the known biological actions of PKD and suppressed cancer-associated properties of proliferation, migration and invasion of prostate cancer cells. Importantly, this inhibitor was not competitive with ATP for enzyme inhibition and was highly selective for PKD when compared to at least 20 different kinases including CAMKII1, AKT, PKA and several PKC isoforms. Most critically, structural optimization of CID755673 has yielded a novel benzthiophene derivative kb-NB142-70 with low nanomolar potency and greater selectivity for PKD. We hypothesize that CID755673 can be optimized to a class of novel PKD inhibitors with unique mechanisms of action for potent and selective blockade of PKD functionality. Our long term goal is to establish a systemic approach to develop CID755673-derived probe molecules as innovative PKD inhibitors. Our proposed research strategies focus on lead optimization, mechanistic evaluation and in vivo efficacy assessment of CID755673 and its analogs. Three specific aims are proposed, representing the first major effort towards the development of potent and selective pharmacological ablative agents for PKD: Aim 1. Optimize CID755673 by structural modifications to access more potent and selective derivatives. Aim 2. Determine the molecular mechanisms underlying the exquisite selectivity of CID755673 and its analogs for PKD. Aim 3. Test the hypothesis that CID755673 and derivatives cause potent and selective blockade of PKD functionality in vivo. PUBLIC HEALTH RELEVANCE: The protein kinase D family is a novel receptor of the key second messenger diacylglycerol and an emerging therapeutic target for cancer and other diseases. Further understanding the role of PKD in biological processes and targeting it in human diseases have been severely impeded by the lack of a PKD-specific inhibitor that can be readily applied to cells and in animals. We have recently discovered the first potent and selective cell-active small molecule inhibitor for PKD - CID755673. We hypothesize that CID755673 can be optimized to generate a class of novel PKD inhibitors with unique mechanisms of action for potent and selective blockade of PKD functionality. The proposed studies focus on lead optimization, mechanistic evaluation and in vivo efficacy assessment of these novel chemical entities. The successful completion of the study will lead to a novel class of PKD inhibitors that can be used as powerful tools for dissecting PKD-mediated signaling pathways and functionalities in cells and animals. It will also provide the foundation for potential future clinical development of the compounds as novel antitumor agents.