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

项目摘要 卵巢癌是女性癌症死亡的第五大原因，化疗仍然是女性癌症死亡的主要原因。 几十年的护理标准。虽然70%的高级别浆液性卵巢癌（HGSOC）患者最初 对基于铂的治疗有反应，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，迫切需要确定可针对的脆弱性， HGSOC和开发新的治疗方法，以延长这些患者的生存期。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Drug Predict来识别胺碘酮，一种抗心律失常药物， 作为一种潜在的卵巢癌治疗方法胺碘酮有效降低细胞活力并引发细胞凋亡， 许多患者来源的HGSOC细胞系，包括顺铂耐药的细胞系。这些效应 通过其降解c-Myc的能力介导，c-Myc在>45%的HGSOC患者中过表达。然而，在这方面， 考虑到胺碘酮的剂量限制性毒性，我们应用构效关系分析来鉴定DL 78， 其缺乏hERG活性，但保留了抗癌特性和调节Myc的能力。DL 78是 比胺碘酮显著更有效和肿瘤特异性更高，并且使细胞对铂治疗敏感。在 此外，DL 78迅速诱导G2/M期阻滞和有丝分裂灾难，最终导致几种细胞凋亡。 癌细胞的种类此外，虽然胺碘酮和DL 78都影响Myc的降解，但DL 78 增强Myc在Threatin-58上的磷酸化，从而增加蛋白酶体介导的Myc 降解因此，我们假设DL 78通过Myc降解诱导有丝分裂灾难， 延长纺锤体组装检查点（SAC）激活。我们将通过两个目标来检验这一假设：1） 检查DL 78对SAC活性的影响，并确定其对Myc的依赖性。2)调查这个化合物 在明确定义的患者来源的异种移植物中的体内功效。成功完成这项建议将提高我们的 了解哪些分子过程对卵巢癌细胞的存活至关重要。作为次要结局， 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， 癌的令人鼓舞的培训环境，丰富的核心设施，以及多样化的导师介绍给我 在密歇根大学将促进繁荣完成这些目标，并加强我的专业 作为一名转化型癌症研究者。

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.