Cysteine Depletion-induced Ferroptosis as a Therapeutic Vulnerability i

半胱氨酸耗竭诱导的铁死亡作为一种治疗弱点

• 批准号: 10431474
• 负责人: Shi-Yuan Cheng
• 金额: $ 24万
• 依托单位: NORTHWESTERN UNIVERSITY AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-06-15 至 2024-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10431474
• 关键词: Adult; Animal Model; Attention; Binding; Biological Markers; Blood - brain barrier anatomy; Cell Death; Cells; Clinical; Cysteine; Data; Diagnosis; Disease Resistance; Drug resistance; Enzymes; Glioblastoma; Glioma; Glutamates; Glutathione; Goals; In Vitro; Ions; Iron; Knowledge; Malignant - descriptor; Metabolic; Mitochondria; Molecular; Neuroprotective Agents; Operative Surgical Procedures; Pathway interactions; Patient Selection; Patients; Pharmaceutical Preparations; Primary Brain Neoplasms; Production; Prognostic Marker; Radiation; Reactive Oxygen Species; Recurrence; Recycling; Regimen; Resistance; Role; Selenium; Specimen; Testing; Therapeutic; antiporter; base; cancer cell; clinical care; deprivation; ebselen; glutathione peroxidase; insight; mimetics; novel therapeutics; patient derived xenograft model; pre-clinical; prevent; refractory cancer; temozolomide; tumor; uptake

Glioblastoma is the most malignant and commonly diagnosed primary brain tumor in adults with a dismal median overall survival of 14 to 16 months. In 2005 the Stupp regimen changed clinical care with the discovery that the chemotherapeutic drug temozolomide (TMZ), with the addition of surgery and radiation, could extend patient survival. However, new therapeutic avenues have remained stagnant and with no second-line therapeutic options showing significant improvement in recurrent GBM tumors, resistance to TMZ is uniformly fatal. To this end we sought to better understand the molecular mechanisms of TMZ-resistant disease to provide patients a potential second-line therapeutic option with a focus on cysteine depletion-induced ferroptosis in TMZ- resistant GBM. Ferroptosis is an iron-dependent form of cell death which has recently gained attention as an attractive avenue to eradicate otherwise drug resistant cancer cells. Our preliminary data support the role of a previously uncharacterized metabolic enzyme in the induction of cysteine depletion-induced ferroptosis. Our findings strongly suggest that the gamma (γ)-glutamyl enzyme (γ-glutamylcyclotransferase; GGCT) recycles cysteine and prevents glutathione (GSH) production – the main goal of the γ-glutamyl pathway. We further show that TMZ-resistant cells have changes consistent with a sensitivity to ferroptosis induction such as an increase in reactive oxygen species (ROS), cysteine uptake and the cysteine/glutamate antiporter – xCT, as well as mislocalized perinuclear mitochondria. Therefore, we sought to repurpose ebselen, a previously characterized neuroprotective agent that was thought to be a glutathione peroxidase 4 (GPX4) mimetic but has recently garnered attention for its selenium ion’s ability to covalently bind cysteines. We show that the neuroprotective agent ebselen which has already been shown to cross the blood brain barrier – a major hurdle for GBM treatment – specifically targets TMZ-resistant GBM cells in vitro. Based on these results, we propose to further investigate the role of cysteine recycling via GGCT and its therapeutic potential as a treatment vulnerability in patient-derived xenograft (PDX) TMZ-resistant GBM orthotopic pre-clinical animal models. Lastly, we seek to establish prognostic biomarkers of this aberrant cysteine recycling through a metabolic byproduct of GGCTs enzymatic activity in clinical glioma specimens. Overall, this proposal will give insight into a new avenue of ferroptosis induction in drug resistant GBM, and potentially pave the way for cysteine deprivation-induced ferroptosis in other drug resistant cancers.

胶质母细胞瘤是成人中最恶性且最常诊断的原发性脑肿瘤 中位总生存期仅为 14 至 16 个月，令人沮丧。2005 年，Stupp 方案改变了临床。 护理发现化疗药物替莫唑胺（TMZ），并添加 手术和放射治疗可以延长患者的生存期，但是，新的治疗途径已经出现。 仍然停滞不前，没有二线治疗方案显示出显着改善 在复发性 GBM 肿瘤中，对 TMZ 的耐药性都是致命的。为此，我们寻求更好的方法。 了解 TMZ 耐药疾病的分子机制，为患者提供潜在的治疗方案 二线治疗选择，重点是 TMZ 中半胱氨酸耗尽引起的铁死亡 抗性 GBM 铁死亡是一种最近出现的铁依赖性细胞死亡形式。 作为根除耐药癌细胞的一种有吸引力的途径而受到关注。 初步数据支持以前未表征的代谢酶在 我们的研究结果强烈表明，半胱氨酸耗尽引起的铁死亡。 (γ)-谷氨酰酶（γ-谷氨酰环转移酶；GGCT）回收半胱氨酸并防止 谷胱甘肽（GSH）的产生——γ-谷氨酰途径的主要目标我们进一步表明。 TMZ 抗性细胞具有一致的变化，并对铁死亡诱导敏感，例如 活性氧（ROS）、半胱氨酸摄取和半胱氨酸/谷氨酸逆向转运蛋白增加 – xCT 以及错误定位的核周线粒体因此，我们寻求重新调整用途。 ebselen，一种先前被认为是谷胱甘肽的神经保护剂 过氧化物酶 4 (GPX4) 模拟物，但最近因其硒离子能够 我们证明神经保护剂依布硒啉已经与半胱氨酸共价结合。 已被证明可以跨越血脑屏障 - GBM 治疗的主要障碍 - 特别是 基于这些结果，我们建议进一步研究。 通过 GGCT 回收半胱氨酸的作用及其作为治疗脆弱性的治疗潜力 在患者来源的异种移植（PDX）TMZ耐药GBM原位临床前动物模型中。 最后，我们寻求通过以下方法建立这种异常半胱氨酸回收的预后生物标志物： 临床神经胶质瘤标本中 GGCT 酶活性的代谢副产物。 该提案将深入了解耐药 GBM 中诱导铁死亡的新途径，以及 可能为其他耐药性中半胱氨酸剥夺引起的铁死亡铺平道路 癌症。