Targeted Inhibition of EGFR Dimerization

 描述(由申请人提供)：有很大的需要开发靶向抑制激酶的替代策略。作为选择性激酶靶向的另一种选择，这项研究的重点是针对变构激活机制的化学受限多肽的开发。这项提议是发展的关键的第一步。 一种强大的新工具，用于开发基于多肽的变构激酶抑制剂。这项工作的长期目标是开发针对与癌症相关的激酶激活的变构效应器。这项应用的总体目标是开发基于多肽的新型化合物，破坏参与EGFR变构激活的蛋白质-蛋白质相互作用(PPI)。中心假设是，通过靶向调节PPI的EGFR的替代保守表面而不是ATP或EGF结合位点，可以有效地抑制EGFR，并且这种靶向策略可以在对当前的EGFR靶向治疗无效的患者中保持活性。拟议项目的基本原理是，通过开发变构EGFR抑制剂获得的知识有可能转化为创新的、高度特异的靶向策略，成功地抑制癌症中的各种激酶。这一假设将通过追求两个具体目标来验证：1)评估不同类别的EGFR靶向治疗耐药性中受限制的EGFR二聚臂多肽的抑制性能；以及2)优化模拟EGFR二聚臂的受限制多肽的抑制性能。这项工作的预期结果将是重大的。首先，这项研究将验证变构激酶激活机制可以被靶向抑制的概念。接下来，将通过监测ErbB同源和异源二聚体的形成来确定这些替代靶向方法是否可以抑制EGFR表达水平不同或对EGFR靶向治疗具有耐药性的肺癌细胞株。ErbB的抑制作用将在具有不同耐药机制的细胞系中得到广泛的表征。在电子计算机中，也将应用方法来优化配基结合和有效性，并将以生物化学的方式验证化合物。最终，本研究中开发的合成策略也可以应用于不同的蛋白质-蛋白质相互作用表面。这项工作将做出重大贡献 对我们设计靶向激酶变构的化合物的理解。本申请中提出的研究具有创新性，因为它代表了对现状的新的和实质性的偏离，提出了PPI在激酶激活中发挥重要作用，因此可以使用替代的合成策略来靶向变构激活机制，包括本研究中包括的靶向和抑制PPI界面的新化合物。这一贡献意义重大，因为它无疑将揭示抑制EGFR和其他受体酪氨酸激酶的新的替代方法。

 DESCRIPTION (provided by applicant): There is a significant need for development of alternative strategies for targeted kinase inhibition. As an alternative for selective kinase targeting, this study is focused on the development of chemically constrained peptides that target allosteric activation mechanisms. This proposal is the crucial first step in the development of a powerful new tool towards developing peptide-based allosteric inhibitors of kinases. The long-term goal of this work is to develop allosteric effectors that target kinase activation as it relates to cancer. The overall objective for this application is to develop novel, peptide-based compounds that disrupt protein-protein interactions (PPIs) involved in allosteric activation of EGFR. It is the central hypothesis that by targeting alternative conserved surfaces of EGFR that regulate PPIs rather than the ATP or EGF binding sites, EGFR can be effectively inhibited and this targeting strategy may retain activity in patients that are unresponsive to current EGFR-targeted therapies. The rationale underlying the proposed project is that the knowledge gained by developing allosteric EGFR inhibitors has the potential to translate into innovative, highly specific targeting strategies for successful inhibition of diverse kinases in cancer. This hypothesis will be tested by pursuing two specific aims: 1) Evaluate inhibitory properties of constrained EGFR dimerization arm peptides in different classes of resistance to EGFR-targeted therapies; and 2) Optimize inhibitory properties of constrained peptides mimicking the dimerization arm of EGFR. The expected outcomes of this work will be significant. First, this study will validate the concept that allosteric kinase activation mechanisms can be targeted for inhibition. Next, it will be determined whether these alternative targeting approaches can inhibit lung cancer cell lines that either differ in EGFR expression levels or are resistant to EGFR-targeted therapies by monitoring formation of ErbB homo- and heterodimers. ErbB inhibition will be extensively characterized in cell lines with various resistance mechanisms. In silico approaches will also be applied to optimize ligand binding and efficacy and will validate the compounds biochemically. Ultimately, the synthetic strategies developed in this study can also be applied to diverse protein-protein interaction surfaces. This work will contribute significantly to our understanding of designing compounds that target kinase allostery. The research proposed in this application is innovative because it represents a new and substantive departure from the status quo by proposing that PPIs play a significant role in kinase activation and therefore allosteric activation mechanisms can be targeted using alternative synthetic strategies including novel compounds included in this study that target and inhibit the PPI interface. This contribution is significant because it will undoubtedly reveal new, alternative approaches for inhibition of EGFR and other receptor tyrosine kinases.