Identification of a targeted anti-mitotic agent that degrades Myc and specifically induces cancer cell death

项目总结 卵巢癌是女性癌症死亡的第五大原因，化疗仍然是导致女性死亡的主要原因 几十年来的护理标准。尽管70%的高级别浆液性卵巢癌(HGSOC)患者最初 对于以铂为基础的治疗，几乎所有患者都因缺乏治疗复发的疗法而死亡， 耐化疗的疾病。因此，迫切需要确定有针对性的漏洞 HGSOC并开发新的治疗方法来延长这些患者的生存时间。为了解决这个问题，我们的实验室 使用计算药物重新定位平台，药物预测，识别抗心律失常药物胺碘酮， 作为一种潜在的卵巢癌治疗方法。胺碘酮有效地降低了细胞存活率并引发了细胞凋亡 大量患者来源的HGSOC细胞系，包括那些对顺铂具有耐药性的细胞系。这些影响是 通过其降解c-Myc的能力，c-Myc在45%的HGSOC患者中过度表达。然而， 鉴于胺碘酮的剂量限制性毒性，我们应用构效关系分析对DL78进行了鉴定。 它缺乏HERG活性，但保留了抗癌特性和调节Myc的能力。DL78是 比胺碘酮更有效和更具肿瘤特异性，并使细胞对铂治疗敏感。在……里面 此外，DL78迅速诱导G2/M期停滞和有丝分裂灾难，最终导致几个 癌细胞的类型。此外，虽然胺碘酮和DL78都影响Myc的降解，但DL78 增强苏氨酸-58上Myc的磷酸化，从而增加蛋白酶体介导的Myc 退化。因此，我们假设DL78通过Myc的降解和 长时间激活主轴组件检查点(SAC)。我们将通过两个目标来检验这一假设：1) 检测DL78对SAC活性的影响，并确定其对Myc的依赖性。2)调查该化合物在 明确定义的患者来源的异种移植物的体内疗效。这项提案的成功完成将改善我们的 了解哪些分子过程对卵巢癌细胞的生存至关重要。作为次要结果， 它提供了一种化合物，可以进一步开发为卵巢和其他Myc驱动的临床前候选药物 癌症。向我展示了令人鼓舞的培训环境、丰富的核心设施和多样化的指导 在密歇根大学的工作将促进这些目标的顺利完成，并增强我的专业水平 作为转化型癌症研究人员的发展。

PROJECT SUMMARY Ovarian cancer is the fifth leading cause of cancer death in women and chemotherapy has remained the standard of care for decades. Although 70% of high grade serous ovarian cancer (HGSOC) patients initially respond to platinum-based therapy, nearly all patients succumb due to lack of therapies to treat recurrent, chemotherapy-resistant disease. Therefore, there is an urgent need to identify targetable vulnerabilities of HGSOC and to develop new treatments to prolong survival of these patients. To address this problem, our lab used a computational drug repositioning platform, Drug Predict, to identify amiodarone, an antiarrhythmic agent, as a potential ovarian cancer treatment. Amiodarone potently decreased cell viability and triggered apoptosis in numerous patient-derived HGSOC cell lines, including those that were cisplatin-resistant. These effects were mediated through its ability to degrade c-Myc, which is overexpressed in >45% of HGSOC patients. However, given the dose-limiting toxicity of amiodarone, we applied structure-activity relationship analysis to identify DL78, which lacked hERG activity but retained the anti-cancer properties and ability to regulate Myc. DL78 was significantly more potent and tumor specific than amiodarone, and sensitized cells to platinum therapy. In addition, DL78 rapidly induced G2/M arrest and mitotic catastrophe, which ultimately led to apoptosis in several types of cancer cells. Furthermore, though both amiodarone and DL78 affected degradation of Myc, DL78 enhanced Myc phosphorylation on Threonine-58, consequently increasing proteasome-mediated Myc degradation. Thus, we hypothesize that DL78 induces mitotic catastrophe through Myc degradation and prolonged spindle assembly checkpoint (SAC) activation. We will test this hypothesis through two aims: 1) Examine DL78 effects on SAC activity and determine its dependency on Myc. 2) Investigate the compound’s in vivo efficacy in well-defined patient-derived xenografts. Successful completion of this proposal will improve our understanding of what molecular processes are vital to ovarian cancer cells’ survival. As a secondary outcome, it provides a compound that can be further developed into a preclinical candidate for ovarian & other Myc-driven cancers. The encouraging training environment, plentiful core facilities, and diverse mentorship presented to me at the University of Michigan will facilitate prosperous completion of these aims and bolster my professional development as a translational cancer researcher.