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

项目摘要 三阴性乳腺癌（TNBC）是一种侵袭性和致命性乳腺癌亚型， 在年轻（<40岁）的有色人种女性（西班牙裔和非裔美国人）中诊断，他们更有可能患有 疾病复发和总体生存期较短的患者。此外，其他限制（即药物） 毒性和治疗抗性）持续存在于TNBC患者的临床中。因此，迫切需要发现 选择性靶向TNBC肿瘤细胞，同时保留正常 细胞不受影响，增强完全反应并降低TNBC相关死亡率。因此，委员会认为， 我们的目标是通过识别TNBC的独特脆弱性来降低BC死亡率， 选择性治疗药物的开发。我们最近发现了天然产物麦角甾醇过氧化物a 在真菌中发现的甾体化合物，作为针对TNBC细胞模型的有效抗增殖剂， 对非癌细胞的影响我们证明EP对TNBC比HER 2阳性更有效。 模型EP在TNBC细胞中诱导ROS和凋亡，并在体内TNBC模型中减小肿瘤体积。 然而，EP的作用方式（MOA）仍有待确定。长期的氧化应激， 线粒体导致受损蛋白质的积累，这些蛋白质通常通过线粒体的泛素化而被去除。 VCP/ANKZF 1通路。我们已经合成了EP在克规模和显示EP积累在胞质溶胶 并影响VCP和ANKZF 1的相互作用，提高了VCP/ANKZF 1复合物被靶向的可能性。 在到达线粒体之前的组装过程中。因此，利用TNBC对固醇的依赖性， 摄取，去除错误折叠的蛋白质和改变氧化还原稳态，我们建议，EP作为一个 VCP/ANKZF 1复合蛋白-蛋白抑制剂（PPI）。我们假设EP靶向VCP/ANKZF 1 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。为了验证这一假设，我们将确定EP靶向 VCP/ANKZF 1复合物在TNBC模型中的作用（目的1）。的 该目的的结果将验证靶向VCP/ANKZF 1复合物诱导错误折叠和 聚集的蛋白质，导致癌细胞死亡。我们将使用同基因的 注射多西环素诱导的ANKZF 1沉默细胞的模型，以及TNBC PDX中。EP安全性和生物- 还将通过MTD和PK/PD（目标2）确定和研究可用性。这一目标的结果将提供 为下一步EP的翻译开发提供了所需的数据。学生参与其中 假设驱动的研究将改善管道URM学生在生物医学研究，并导致 改善BC治疗。

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.