Development and Application of Selective Covalent Cdk7 Inhibitors

描述（由申请人提供）：选择性蛋白激酶抑制剂是询问细胞信号通路和验证治疗多种癌症的药物靶点的强大工具。今天存在的药物发现范式首先是在学术机构对激酶靶点的鉴定和验证，然后是制药部门的抑制剂开发。这种模式的一个主要缺点是，大多数激酶的选择性抑制剂严重短缺，阻碍了最初的药理学概念验证研究，因此阻碍了制药部门对这些靶点的进一步探索。我们的实验室试图通过开发有效的方法来发现一流的激酶抑制剂来解决这一缺陷，然后将其用作药理“工具”来研究所讨论的激酶的功能和潜在的治疗相关性。在过去的五年中，我们的实验室已经开发并广泛销售了ALK， Mps1, Erk5, mTor, LRRK2, fgfr， JNKs和T790M突变形式的EGFR的第一批抑制剂；其中有几种是目前的标准对照化合物。在这项应用中，我们组建了一个多学科团队，整合了药物化学（Nathanael Gray）、结构生物学（Jane Endicott）、转录（Richard Young）、癌症生物学和转化研究（Constantine Mitsiades），这将使首个高效和选择性CDK7抑制剂的开发和应用成为可能。周期蛋白依赖性激酶是一类高度保守的蛋白激酶，由20个成员（CDK1-20）组成，这些成员与29个被称为周期蛋白的调节蛋白家族相关。它们调节大量细胞功能，包括细胞周期（CDK1-6）、转录（cdk7 - 13,19）和剪接（CDK11）。虽然细胞周期调节CDKs作为药物发现靶点受到了大量关注，但所谓的“转录CDKs”（tCDKs - cdk7 - 13,19）却很少受到关注。我们发现了一种前所未有的开发选择性CDK7抑制剂的方法，通过共价靶向位于激酶结构域外的独特半胱氨酸（Cys）残基。我们已经获得了CDK7抑制剂在大量癌症中活性的令人信服的初步数据，但在这里，我们建议重点研究靶向CDK7治疗多发性骨髓瘤的潜力，多发性骨髓瘤是一种浆细胞肿瘤，过度转录是该疾病的标志，根据我们的初步数据，CDK7起着关键的病理生理作用。这将通过集中的药物化学活动（目标1）和详细的机制表征（目标2）来完成，随后在多发性骨髓瘤细胞和小鼠模型中进行临床前评估（目标3）。

DESCRIPTION (provided by applicant): Selective protein kinase inhibitors are powerful tools for interrogating cellular signaling pathways and validating drug targets for the treatment of a variety of cancers. The drug discovery paradigm that exists today starts with the identification and validation of kinase targets primarily at academic institutions followed by inhibitor development by the pharmaceutical sector. A major shortcoming of this paradigm is the severe shortage of selective inhibitors for most kinases hampers initial pharmacological proof-of-concept studies and therefore discourages further exploration of these targets by the pharmaceutical sector. Our laboratory has attempted to address this deficiency by developing efficient approaches to the discovery of first-in-class kinase inhibitors, which are then used as pharmacological 'tools' to investigate the functions and potential therapeutic relevance of the kinase in question. Over the last five years, our laboratory has developed and widely distributed the first inhibitors of ALK, Mps1, Erk5, mTor, LRRK2, FGFRs, JNKs, and the T790M mutant form of EGFR; several of which are currently standard reference compounds. In this application we have assembled a multidisciplinary team that integrates medicinal chemistry (Nathanael Gray), structural biology (Jane Endicott), transcription (Richard Young) and cancer biology and translational research (Constantine Mitsiades) that will enable the development and application of the first highly potent and selective inhibitors of CDK7. The cyclin-dependent kinases are a highly conserved class of protein kinases that consist of 20 members (CDK1-20) that associate with a family of 29 regulatory proteins called cyclins. They regulate a large number of cellular functions including cell cycle (CDK1-6), transcription (CDK7-13, 19), and splicing (CDK11). While the cell cycle regulating CDKs have received a significant amount of attention as drug discovery targets the so-called 'transcriptional CDKs' (tCDKs - CDK7-13, 19) have received much less. We have discovered an unprecedented means of developing selective CDK7 inhibitors by covalently targeting a unique cysteine (Cys) residue located outside of the kinase domain. We have obtained compelling preliminary data of the activity of CDK7 inhibitors in a large number of cancers, but here we propose to focus on investigating the potential of targeting CDK7 for the treatment of Multiple Myeloma, a plasma cell tumor where excess transcription is a hallmark of the disease and, based on our preliminary data, CDK7 plays a critical pathophysiological role. This will be accomplished through a focused medicinal chemistry campaign (Aim 1) and guided by detailed mechanistic characterization (Aim 2), followed by preclinical evaluation in cellular and murine models of Multiple Myeloma (Aim 3).