A Chemical Genetic Approach to Exploring Novel Therapeutic Space for Colorectal Cancer

项目摘要 转移性结直肠癌(Mcrc)是美国癌症相关死亡的第二大原因。 全球每年有近50万人死于这一疾病。目前，小分子激酶 抑制剂(Ki)瑞格非尼是治疗转移性结直肠癌的主要二线疗法，不能用 免疫疗法或抗EGFR疗法。然而，regorafenib通常在以下方面仅提供适度的改善 存活--通常是几个月--而且往往以显著的副作用为代价。瑞格拉非尼的拟议目标 包括在肿瘤细胞内以及非自主作用的激酶；然而，有500多个可能的靶点 在人类基因组中，这种化合物的确切作用机制仍然存在争议，没有 完全出名了。这是一项艰巨的挑战；没有可核查的目标或机制，就不存在明确的道路 指导多发性结直肠癌改进治疗方法的发展。 在这里，我们提出了一种替代药物开发的方法，该方法侧重于 整个动物的背景。具体地说，我们将采用多学科方法来定义 在KRAS变种CRC的情况下，有利于抑制(“亲目标”)或避免(“反目标”)。使用果蝇 和哺乳动物模型，我们将识别当减少时改变regorafenib和 相似的化合物。我们还将进行广泛的结构-活动关系分析，评估如何 已确定的先导化合物的修饰会影响疗效和治疗指数的变化。最后，我们 将使用计算结构生物学将我们的化学遗传洞察转化为高度优化和 精确的复合药理线索。在这最后一步中，我们生成新的类比，以选择性地消除假定的 抗靶标活性，同时保持或增加对其他有益靶标的抑制活性。 我们已经利用我们的化学遗传平台鉴定了一种有希望的先导化合物APS5-86-2，它 在包括人类患者在内的多个mCRC模型中显示出与regorafenib相关的显著活性 衍生异种移植物(PDX)。比较分析表明，APS5-86-2的活性相对于 Regorafenib源于对几种RTK和关键癌症驱动因素的不同多元药理学，包括CDK9， AURKA、EGFR、BRAF和RAF1。在这项建议中，我们研究了这些和 使用基因分析和体内靶点参与的其他推定的亲靶和反靶蛋白激酶。目标是 是通过结合化学生物学和遗传学来鉴定介导KRAS变异型mCRC的激酶网络， 然后通过基于结构的药物设计来获得最好地攻击这些网络的抑制剂。我们一直在 以前用类似的方法成功，但在不太复杂的肿瘤模型中(Dar等人，自然，2012年； Sonoshita等人，自然化学。生物，2018)；在这里，我们寻求将我们的平台扩展到一种更流行的疾病 目标是通过创造新的、高度分化的和改进的药物来直接影响mcrc。

Project Summary Metastatic colorectal cancer (mCRC) is the second leading cause of cancer-related mortality in the United States, and annually accounts for nearly 500,000 deaths worldwide. Currently, the small molecule kinase inhibitor (KI) regorafenib is the primary second line therapy for metastatic CRC that is not treatable with immunotherapy or anti-EGFR therapies. However, regorafenib generally provides only modest improvements in survival— typically months—and often at the cost of significant side effects. Proposed targets for regorafenib include kinases that act within tumor cells as well as non-autonomously; however, with over 500 possible targets in the human kinome, the exact mechanism by which this compound operates remains controversial and not fully known. This presents a daunting challenge; without a verifiable target or mechanism, no clear path exists to guide the development of improved therapies for mCRC. Here, we propose an alternative approach to drug development that focuses on kinase networks in the context of the whole animal. Specifically, we will take a multidisciplinary approach to define kinases that are beneficial to inhibit (‘pro-targets’) or avoid (‘anti-targets’) in the context of KRAS-variant CRC. Using Drosophila and mammalian models, we will identify kinases that—when reduced—alter the efficacy of regorafenib and similar compounds. We will also conduct extensive structure-activity relationship analyses, evaluating how modifications in already identified lead compounds impact changes in efficacy and therapeutic index. Finally, we will use computational structural biology to convert our chemical genetic insights into highly optimized and precise polypharmacological leads. In this final step, we generate new analogs to selectively eliminate putative anti-target activity while maintaining or increasing inhibitory activity against other beneficial targets. We have used our chemical genetic platform to identify a promising lead compound, APS5-86-2, that demonstrates significant activity relative to regorafenib in several mCRC models, including human patient derived xenografts (PDX). Comparative analysis suggests that the improved activity of APS5-86-2 relative to regorafenib derives from distinct polypharmacology on several RTKs and critical cancer drivers, including CDK9, AURKA, EGFR, BRAF, and RAF1. In this proposal, we examine the mechanism and importance of these and other putative pro- and anti-target kinases using genetic analysis and in vivo target engagement. The objective is to identify the kinase networks that mediate KRAS-variant mCRC by combining chemical biology with genetics, and to then derive inhibitors that best attack these networks through structure-based drug design. We have been successful previously with a similar approach, but in less complex tumor models (Dar et al., Nature, 2012; Sonoshita et al., Nature Chem. Bio., 2018); here we seek to extend our platform to a more prevalent disease with the goal of directly impacting mCRC by creating new, highly differentiated, and improved drugs.