Identification of novel system xc- inhibitors

新型系统 xc-抑制剂的鉴定

• 批准号: 8359138
• 负责人: Barbara Stauch Slusher
• 金额: $ 20.25万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-30 至 2014-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8359138
• 关键词: Alzheimer' s Disease; Amino Acid Transporter; Animal Model; Antioxidants; Astrocytes; Biological Assay; Biological Factors; Brain Neoplasms; Cell membrane; Cells; Chemicals; Clinical Research; Couples; Cystine; Dependency; Detection; Development; Dimethyl Sulfoxide; Disease; Dose; Epilepsy; Extracellular Space; Future; Genetic; Glioma; Glutamate Transporter; Glutamates; Glutathione; Goals; Growth; HIV; In Vitro; Inhibitory Concentration 50; Laboratories; Lead; Libraries; Malignant Neoplasms; Malignant neoplasm of brain; Measurement; Metabolism; Microglia; Molecular; Multiple Sclerosis; Nerve Degeneration; Neurocognitive; Neurodegenerative Disorders; Neurons; Oxidation-Reduction; Parkinson Disease; Pathogenesis; Pharmaceutical Preparations; Play; Property; Proteins; Reaction; Reactive Oxygen Species; Regulation; Reporting; Role; Running; Screening procedure; Seizures; Signal Transduction; Staging; Structure-Activity Relationship; Sulfasalazine; System; Testing; Therapeutic; Time; Tissues; Toxic effect; Translating; Tumor Expansion; Up-Regulation; Validation; Variant; analog; antiporter; cancer cell; cancer therapy; cell growth; cell type; drug discovery; experience; extracellular; ginsenoside M1; high throughput screening; in vivo; inhibitor/antagonist; macrophage; miniaturize; neuron loss; neuroprotection; novel; pharmacophore; prototype; response; small molecule; small molecule libraries; therapeutic target; tumor growth; uptake

DESCRIPTION (provided by applicant): The overall aim of this proposal is to develop a 96-well plate screening assay that will allow screening for small molecule inhibitors of the cystine-glutamate antiporter, also known as system Xc-. System Xc- is a Na+-independent amino acid transporter that couples the export of intracellular L-glutamate with the import of extracellular L cystine. Cystine transport is critical for glutathione synthesis, an intracellular antioxidant whic protects cells from reactive oxygen species. Decreased glutathione levels lead to cellular growth arrest which has made system Xc- a target in cancer therapy, including brain cancer. In brain cancers, the release of glutamate via the antiporter raises additional concerns, as high levels of extracellular glutamate leads to peritumoral neuronal cell death aiding in tumor expansion by clearing surrounding tissue space. In addition to brain cancer, excessive glutamate release via system Xc- has also been shown to play a significant role in several neurodegenerative diseases wherein excess glutamate is presumed pathogenic, including Parkinson's disease, Alzheimer's disease, Multiple Sclerosis and epilepsy, which makes system Xc- a broad therapeutic target for neurodegenerative disorders. There are no selective and potent small molecule system Xc- inhibitors available to the public, and to our knowledge no high throughput screening for this target has been performed. As such, we propose to develop an HTS-ready 96-well assay to screen for novel chemical entities that inhibit system Xc- activity. We will validate this assay by screening four chemical libraries composed of clinically approved drugs as well as non-clinical compounds. The hits will be confirmed in a secondary screening assay and active novel compounds will be moved into structure activity relationship (SAR) studies guided by Xc- potency and in vitro drug- ability assays of metabolism, toxicity and target selectivity. As a future goal, lead compounds arising from these studies will be tested in animal models of glioma and multiple sclerosis and the validated 96-well assay will be further miniaturized to a 384-well format for high throughput screening of the NIH's >300 K compound library. PUBLIC HEALTH RELEVANCE: System Xc- is up-regulated in a variety of cancers and neurodegenerative diseases, and its inhibition with prototype small molecules or genetic deletion inhibits tumor growth in vivo and provides protection in animal models of neurodegeneration. There are no selective and potent small molecule system Xc- inhibitors modulators available to the public, and to our knowledge no high throughput screening (HTS) for this target has been performed. As such, we propose to develop an HTS-ready 96-well assay, screen multiple chemical libraries, and advance hits into a structure activity relationship (SAR) studies guided by Xc- potency and in vitro drug-ability assays of metabolism, toxicity and target selectivity.

描述（由申请人提供）：本提案的总体目标是开发一种 96 孔板筛选测定法，该测定法将允许筛选胱氨酸-谷氨酸逆向转运蛋白（也称为系统 Xc-）的小分子抑制剂。 System Xc- 是一种不依赖 Na+ 的氨基酸转运蛋白，它将细胞内 L-谷氨酸的输出与细胞外 L-谷氨酸的输入耦合起来 胱氨酸。胱氨酸转运对于谷胱甘肽合成至关重要，谷胱甘肽是一种细胞内抗氧化剂，可保护细胞免受活性氧的侵害。谷胱甘肽水平降低会导致细胞生长停滞，这使得 Xc 系统成为癌症治疗（包括脑癌）的目标。在脑癌中，通过反向转运蛋白释放谷氨酸引起了额外的担忧，因为高水平的细胞外谷氨酸会导致瘤周神经元细胞死亡，通过清除周围的组织空间来帮助肿瘤扩张。除了脑癌之外，Xc- 系统释放的过量谷氨酸也被证明在多种神经退行性疾病中发挥着重要作用，其中过量的谷氨酸被认为是致病的，包括帕金森病、阿尔茨海默病、多发性硬化症和癫痫，这使得 Xc- 系统成为神经退行性疾病的广泛治疗靶点。目前还没有可供公众使用的选择性且有效的小分子系统 Xc 抑制剂，而且据我们所知，尚未对该靶标进行高通量筛选。因此，我们建议开发一种 HTS 就绪的 96 孔测定法来筛选抑制系统 Xc 活性的新型化学实体。我们将通过筛选由临床批准的药物以及非临床化合物组成的四个化学库来验证该测定。这些命中将在二次筛选测定中得到确认，活性新颖化合物将进入结构活性关系（SAR）研究，以 Xc 效力和代谢、毒性和靶点选择性的体外成药性测定为指导。作为未来的目标，这些研究中产生的先导化合物将在神经胶质瘤和多发性硬化症的动物模型中进行测试，并且经过验证的 96 孔测定将进一步小型化为 384 孔格式，用于 NIH > 300 K 化合物库的高通量筛选。 公共健康相关性：系统 Xc- 在多种癌症和神经退行性疾病中上调，通过原型小分子或基因删除对其进行抑制可抑制体内肿瘤生长，并为神经退行性动物模型提供保护。目前还没有可供公众使用的选择性有效的小分子系统 Xc 抑制剂调节剂，而且据我们所知，尚未对该靶标进行高通量筛选 (HTS)。因此，我们建议开发一种 HTS 就绪的 96 孔测定法，筛选多个化学文库，并在 Xc 效力和代谢、毒性和靶点选择性的体外成药能力测定指导下，将命中的化合物推进到结构活性关系 (SAR) 研究中。