Validating the mode of action of ergosterol peroxide as a selective breast cancer inhibitor

项目总结 三阴性乳腺癌(TNBC)是一种更常见的侵袭性和致命性乳腺癌亚型 诊断对象为年轻(40岁)有色人种女性(西班牙裔和非裔美国人)，她们更有可能患有 疾病复发和总体生存时间较短的患者。此外，其他限制(即药物 毒性和治疗耐药性)在TNBC患者的临床上持续存在。因此，迫切需要发现 更理想的靶向治疗方式，选择性地靶向TNBC肿瘤细胞，同时保持正常 细胞不受影响，增强完全反应并降低与TNBC相关的死亡率。因此， 我们的目标是通过确定TNBC的独特漏洞来降低BC的死亡率，这些漏洞可以通过 选择性治疗剂的开发。我们最近确认了天然产物麦角固醇过氧化氢a 在真菌中发现的类固醇化合物，作为一种有效的抗增殖剂，用于抗TNBC细胞模型，几乎没有 对非癌细胞的影响。我们证明EP对TNBC的作用比HER2阳性更强。 模特们。EP可诱导TNBC细胞内ROS和细胞凋亡，减少体内肿瘤体积。 然而，EP的行动模式(MOA)仍有待定义。氧化应激期延长 线粒体导致受损蛋白质的积累，这些蛋白质通常通过泛素化通过 VCP/ANKZF1通路。我们已经合成了克级的EP，并表明EP在胞浆中积累 并影响VCP和ANKZF1的相互作用，增加了VCP/ANKZF1复合体成为靶点的可能性 在到达线粒体之前的组装过程中。因此，利用TNBC对类固醇的依赖 摄取、去除错误折叠的蛋白质和改变氧化还原平衡，我们认为EP是一种 VCP/ANKZF1复合蛋白-蛋白抑制剂(PPI)。我们假设EP以VCP/ANKZF1为目标 复杂，损害癌细胞清除受损蛋白质的能力，并导致线粒体功能障碍 诱导TNBC细胞死亡。为了检验这一假设，我们将确定EP针对 VCP/ANKZF1复合体在TNBC模型中使用生物物理方法和合成的EP探针(目标1)。这个 来自这一目的的结果将验证靶向VCP/ANKZF1复合体导致错误折叠和 聚集的蛋白质，这会导致癌细胞死亡。我们将使用同源基因来确定EP的疗效 注射多西环素可诱导的ANKZF1沉默细胞模型和TNBC PDX模型。EP安全和生物- 可获得性也将由MTD和PK/PD(目标2)确定和研究。这一目标的结果将提供 为下一步进行EP的翻译开发所需的数据。学生对此的参与 假设驱动的研究将改善URM学生在生物医学研究方面的渠道，并导致 改进了BC处理。

PROJECT SUMMARY Triple Negative Breast Cancer (TNBC) is an aggressive and lethal breast cancer subtype more commonly diagnosed on younger (<40y) women of color (Hispanics and African American), who are more likely to have disease recurrence and who have an overall shorter survival. Furthermore, additional limitations (i.e. drug toxicity, and therapy resistance) persist in the clinic for TNBC patients. Thus, a critical need exists to discover more desirable targeted therapeutic modalities that selectively target TNBC tumor cells while leaving normal cells unaffected, enhancing a complete response and reducing TNBC-associated mortality rates. Accordingly, our goal is to reduce BC mortality by identifying unique vulnerabilities of TNBC that can be exploited through the development of selective therapeutic agents. We recently identified the natural product ergosterol peroxide a steroidal compound found in fungi, as a potent antiproliferative agent against TNBC cell models with little to no effect on noncancerous cells. We demonstrated that EP is more potent towards TNBC than HER2-positive models. EP induces ROS and apoptosis in TNBC cells and reduces tumor volume in TNBC models in vivo. However, EP’s mode of action (MOA) remains to be defined. Extended periods of oxidative stress in the mitochondria lead to accumulation of damaged proteins, which are normally removed by ubiquitination via the VCP/ANKZF1 pathway. We have synthesized EP in gram scale and show that EP accumulates in the cytosol and affects VCP and ANKZF1 interactions, raising the possibility that the VCP/ANKZF1 complex is targeted during its assembly prior to arriving to the mitochondria. Thus, taking advantage of TNBC’s dependency on sterol uptake, removal of misfolded proteins and altered redox homeostasis, we propose that EP serves as a VCP/ANKZF1 complex protein-protein inhibitor (PPI). We hypothesize that EP targets the VCP/ANKZF1 complex, impairing the ability of cancer cells to clear damaged proteins and causing mitochondria dysfunction to induce TNBC cell death. To test the hypothesis we will identify the mechanism by which EP targets the VCP/ANKZF1 complex in TNBC models using biophysical assays and synthesized EP-probes (Aim 1). The results from this Aim will validate that targeting VCP/ANKZF1 complex induces increases misfolded and aggregated proteins, which lead to cancer cell death. We will determine the efficacy of EP using syngeneic models injected with doxycycline inducible ANKZF1 silenced cells, and in TNBC PDXs. EP safety and bio- availability will also be determined and studied by MTD and PK/PD (Aim 2). The result of this aim will provide data needed for the next step towards the translational development of EP. Student participation in this hypothesis-driven research will improve the pipeline for URM students in biomedical research and lead to improved BC treatment.