Ferroptosis in drug resistant glioma

项目摘要 癌症耐药性是延长患者总体生存时间的最后前沿，特别是在致命的 脑肿瘤-胶质母细胞瘤(GBM)。GBM目前有一种标准的护理化疗药物- 替莫唑胺(TMZ)-将中位总生存期延长至约14-16个月。然而，TMZ的阻力是 迅速且一致致命。然而，由于有一些长期应答者(5年时约为5%)，几乎都是新的 确诊的GBM将接受TMZ，使TMZ耐药成为临床上未得到满足的主要需求，我的重点是 以前、现在和将来的工作。我目前工作的中心目标是更好地理解 易感(TMZ-S)和耐药(TMZ-R)疾病之间代谢状态的变化，允许 发现了治疗上有针对性的漏洞。为此，我发现TMZ-R细胞具有 对半胱氨酸进口的更大依赖，细胞内铁的增加，以及维持的氧化状态 这些TMZ-R模型用于使用已知的神经保护剂Ebselen治疗囊性(E)碱耗竭引起的铁性下垂。 我进一步证明，这种形式的铁下垂--或铁依赖的细胞死亡--可以由体内的硒诱导 Ebselen或TMZ-Se，但不是TMZ-S类似物，将不再对TMZ-R细胞产生反应 只有TMZ一个人。因此，这个项目的目标是仔细地描述这个囊性(E)因衰竭- TMZ-R模型诱导的铁下垂表型有助于我们理解TMZ-R GBM和TMZ-R 开发一个小分子含硒化合物可用于其他疾病的框架。 为了实现这一目标，我将充分利用我优秀的指导/咨询委员会以及 西北大学为我提供了特殊的资源和培训环境。预期中的 该项目的成果包括彻底了解新陈代谢格局和 TMZ-S和-R模型，以及耗竭性铁下垂引起的囊后移位(目标1)。一个 介导囊(E)碱耗竭所必需的蛋白分子的特性和验证 TMZ-R模型中的铁性下垂以及TMZ-R中氧化状态的增加如何影响酶的活性 不能通过测序方法发现但对蛋白质活性至关重要的位点状态(目标2)。 最后，从对代谢读数和代谢读数的细致理解中获得的机械知识 蛋白质组玩家将允许更智能的动物模型设计来回答和/或确认AIM 1&中的发现 2(目标3)。因为我在TMZ-R的RNA生物学/剪接和DNA损伤/结构方面已经有了很强的背景 这项建议将加强我在代谢差异方面的知识，并学习蛋白质组学和 新陈代谢技术。通过这种方式，我将对TMZ-R疾病有一个全面的了解，这将有助于我 在未来我运营自己的独立实验室时，设计更智能、更完整的研究。

Project Abstract Cancer drug resistance is the last frontier in extending patient overall survival, especially in the deadly brain tumor – glioblastoma (GBM). GBM currently has one standard of care chemotherapeutic agent – temozolomide (TMZ) – which extends median overall survival to ~14-16 months. However, TMZ resistance is rapid and uniformly fatal. Yet, because there are some long-term responders (~5% at 5 years), almost all newly diagnosed GBMs will receive TMZ, making TMZ-resistance a major clinical unmet need, and the focus of my previous, current, and future work. The central goal of my current work is to better understand the distinct changes in the metabolic states between TMZ-Sensitive (TMZ-S) and -Resistant (TMZ-R) disease, allowing for the discovery of therapeutically targetable vulnerabilities. To this end, I have found that TMZ-R cells have a greater dependence on cystine import, increase of intracellular iron, and a maintained oxidative state that primes these TMZ-R models for cyst(e)ine depletion-induced ferroptosis with a known neuroprotective agent – ebselen. I further show that this form of ferroptosis – or iron-dependent cell death – could be induced by the selenium in ebselen or TMZ-Selenium but not a TMZ-Sulfur analog in TMZ-R cells, which will no longer have a response to TMZ alone. Therefore, the objective of this project is to meticulously characterize this cyst(e)ine depletion- induced ferroptosis phenotype in TMZ-R models where it will both help in our understanding of TMZ-R GBM and develop a framework where small molecule selenium-containing compounds could be of use in other diseases. To accomplish this goal, I will take full advantage of my excellent mentoring/advisory committee as well as the exceptional resources and training environment available to me at Northwestern University. The expected outcomes of this project include a thorough understanding of the metabolic landscape and changes between both TMZ-S and -R models, as well as shifts post cyst(e)ine depletion-induced ferroptosis (Aim 1). A characterization and validation of the protein players that are necessary to mediate cyst(e)ine depletion-induced ferroptosis in TMZ-R models, as well as how the increased oxidative state in TMZ-R may affect enzymatic active site status that would not be discovered via sequencing methods but is essential for protein activity (Aim 2). Finally, the mechanistic knowledge gained from a meticulous understanding of both the metabolic readouts and proteomic players will allow for a smarter animal model design to answer and/or confirm the findings in Aim 1 & 2 (Aim 3). As I already have a strong background in RNA biology/splicing and DNA damage/structure in TMZ-R disease, this proposal will strengthen my knowledge in the metabolic differences and learn proteomic and metabolic techniques. In this way, I will have a well-rounded understanding of TMZ-R disease which will help me to design smarter and more complete studies in the future when I run my own independent lab.