Methodology for Identification of Substrate-Competitive Kinase Inhibitors

描述（由申请人提供）：蛋白酪氨酸激酶（PTK）在细胞信号传导和调节生物过程（如增殖、分化和凋亡）中发挥关键作用。超过164种蛋白激酶与包括癌症、炎症、糖尿病、高血压、血管生成和免疫疾病在内的疾病有关。有400多种疾病与蛋白激酶直接或间接相关。鉴于此，PTK已成为学术界和制药行业药物开发的有吸引力的目标。然而，尽管有大量的靶点，FDA批准的激酶抑制剂以及临床开发中的激酶抑制剂仅靶向少数通过与ATP竞争提供抑制的众所周知的激酶。显然，获得针对多种酪氨酸激酶的有效和选择性ATP竞争性化合物一直是困难的。该提案旨在开发快速鉴定底物竞争性蛋白酪氨酸激酶（PTK）抑制剂的通用和强大的工具。所有目前批准的靶向抑制疾病中涉及的PTK的治疗剂都是ATP竞争性抑制剂。然而，我们认为底物竞争性抑制PTKs提供了几个重要的好处超过ATP竞争性抑制。由于跨PTK的ATP结合口袋的非常高的相似性，获得选择性抑制是特别具有挑战性的。靶激酶的选择性抑制将使治疗剂的脱靶副作用最小化，并为生物学研究提供选择性化学探针。底物竞争性抑制剂代表了由于PTK的非同源底物口袋而朝向选择性激酶抑制的进展。我们计划开发我们的方法，使用四个初始目标：c-Abl，c-Src，和两个必不可少的酪氨酸激酶在锥虫。c-Abl和c-Src均参与癌症进展（分别为慢性髓性白血病（CML）和结肠癌的验证靶点），锥虫PTK是非洲昏睡病（人非洲锥虫病，HAT）的潜在治疗靶点。CML是一种罕见的，不可手术的癌症，在美国每年有超过5,000例新发病例。结肠癌是第三大常见癌症，每年导致超过65万人死亡。非洲昏睡病在西非是一个日益严重的问题，每年造成30万新病例和6万多人死亡。我们认为拟议的研究非常适合尤里卡计划，因为：1）它开发了尖端方法，挑战了通过ATP竞争性化合物抑制激酶的广泛范例，2）创建了一个灵活和强大的平台，用于获得针对疾病进展中涉及的任何激酶靶点的底物竞争性激酶抑制剂。

DESCRIPTION (provided by applicant): Protein tyrosine kinases (PTKs) play a key role in cell signaling and regulating biological processes such as proliferation, differentiation, and apoptosis. More than 164 protein kinases have been implicated in diseases including cancer, inflammation, diabetes, hypertension, angiogenesis, and immune disease. Directly or indirectly, over 400 diseases have been linked to protein kinases. In light of this, PTKs have become attractive targets for drug development in both academia and the pharmaceutical industry. Despite the large number of targets, however, the FDA-approved kinase inhibitiors as well as those in clinical development target only a handful of well-known kinases providing inhibition via competition with ATP. Clearly, obtaining potent and selective ATP-competitive compounds against a wide-variety of tyrosine kinases has been difficult. This proposal aims to develop general and robust tools for the rapid identification of substrate-competitive protein tyrosine kinase (PTK) inhibitors. All current approved therapeutics targeting inhibition of PTKs involved in disease are ATP-competitive inhibitors. However, we believe that substrate-competitive inhibition of PTKs offers several important benefits over ATP-competitive inhibition. Due to very high similiarity in the ATP binding pocket across PTKs, obtaining selective inhibition is particularly challenging. Selective inhibition of a target kinase will minimize off-target side-effects of therapeutics as well as provide selective chemical probes for biological studies. Substrate-competitive inhibitors represent an advance toward selective kinase inhibition owing to the non-homologous substrate pocket of PTKs. We plan to develop our methodology using four initial targets: c-Abl, c-Src, and two essential tyrosine kinases in Trypanosomes. c-Abl and c-Src are both involved in cancer progression (validated targets for chronic myelogenous leukemia (CML) and colon cancer, respectively) and the Trypanosome PTKs are potential therapeutic targets for African sleeping sickness (human African trypanosomiasis, HAT). CML is a rare, inoperable cancer which results in more than 5,000 new cases per year in the United States. Colon cancer is the third most common cancer, resulting in over 650,000 deaths per year. African sleeping sickness is a growing problem in western Africa, resulting in 300,000 new cases per year and over 60,000 deaths per year. We believe the proposed research is well-suited for the EUREKA program because: 1) it develops cutting- edge methodologies which challenge the widespread paradigm of kinase inhibition via ATP-competitive compounds, and 2) creates a flexible and robust platform for obtaining substrate-competitive kinase inhibitors against any kinase target involved in disease progression.