Targeting Mitochondrial Redox Capacity to Overcome Cancer Subtype that Regrowth After Radiation

针对线粒体氧化还原能力来克服放射后再生的癌症亚型

• 批准号: 10817512
• 负责人: Luksana Chaiswing
• 金额: $ 6.16万
• 依托单位: UNIVERSITY OF KENTUCKY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-01 至 2026-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10817512
• 关键词: Animal Model; Antibiotics; Azithromycin; Biochemical; Biogenesis; Cell Death; Cell Survival; Cells; Cellular Metabolic Process; Cessation of life; Clinical Treatment; Computer software; Coupled; Cytoplasm; Data; Dose; Electron Transport; Enzymes; Event; Exhibits; External Beam Radiation Therapy; FDA approved; Failure; Fluorescence Microscopy; Growth; Homeostasis; Hydrogen Peroxide; Image; Impairment; In Vitro; Macrolides; Magnetic Resonance Imaging; Malignant Neoplasms; Malignant neoplasm of prostate; Mediating; Metabolic; Metabolic Pathway; Metabolism; Mitochondria; Mitochondrial DNA; Mitochondrial Proteins; Molecular; Mus; Normal Cell; Oxidation-Reduction; Oxidative Phosphorylation; Pathway interactions; Patients; Pharmaceutical Preparations; Phase; Property; Prostate; Protein Array; Proteins; Radiation; Radiation Tolerance; Radiation therapy; Radiosensitization; Reactive Oxygen Species; Recurrence; Recurrent Malignant Neoplasm; Regulation; Research Design; Resistance; Resistance development; Resolution; Site; Testing; Therapeutic; Time; Translating; Translational Repression; Translations; Treatment Efficacy; Visualization; Xenograft Model; bioluminescence imaging; cancer cell; cancer heterogeneity; cancer recurrence; cancer subtypes; cancer survival; catalase; fractionated radiation; high risk; improved; in vivo; inhibitor; insight; knock-down; metabolomics; mitochondrial dysfunction; mitochondrial metabolism; mortality; mtTF1 transcription factor; novel; novel therapeutics; overexpression; patient derived xenograft model; prevent; prostate cancer cell; prostate cancer model; prototype; radiation delivery; radiation resistance; radioresistant; response; stable isotope; success; tempol; tumor; tumor growth; tumor heterogeneity

ABSTRACT (R01CA251663) Radiation therapy (RT) is widely used to treat localized prostate cancer (PCa). However, cancer cells often develop resistance to RT through unknown mechanisms, resulting in cancer recurrence. To improve RT, there is a dire need to uncover cellular events that cause cells to become resistant. We previously demonstrated that PCa heterogeneity, particularly in prostate cancers with an abundant mitochondria subpopulation, often survive and regrow after RT (termed radiation resistant prostate cancer, or RR-PCa). Elevation of mitochondrial mass, number, reactive oxygen species (ROS), and biogenesis markers is acquired in RR-PCa cells. We further demonstrated that knockdown of the mitochondrial biogenesis regulator, TFAM (transcription factor A, mitochondrial), significantly restored the sensitivity of RR-PCa cells to RT. Hence, our overarching hypothesis is that RT-activated mitochondrial biogenesis, via ROS, is an acquisition mechanism that drives PCa survival post- RT, a premise that will undergo stringent examination in the proposed studies. ROS are known to directly and indirectly regulate mitochondrial homeostasis through fusion, fission, mitophagy, and biogenesis. We screened FDA-approved drugs in search of compounds that are nontoxic to normal cells and have the ability to raise the level of mitochondrial hydrogen peroxide (mtH2O2) in PCa cells while blocking mitochondrial protein translation. We found azithromycin (AZM), a macrolide antibiotic, to be an effective prototype compound that possesses both properties. We further demonstrated that AZM combined with RT enhances the death of PCa cells with an abundant mitochondrial subpopulation, compared to AZM or RT alone. Thus, we propose to advance our findings and identify the mechanism(s) that effectively inhibit the survival of post-irradiated cancer cells, to improve RT efficacy. The specific aims are: 1) to define the molecular mechanism(s) by which RT-activated mitochondrial biogenesis promotes cell survival and metabolic adaptations of PCa cells with abundant mitochondria, both in vitro and in vivo; 2) to determine if overloading mtH2O2 to target inherent mitochondria and RT-acquired mitochondria while blocking mitochondrial protein translation in RT-acquired mitochondria enhances radiosensitivity of RR-PCa cells, and 3) to improve RT using a mtH2O2 generator and a mitochondrial protein translation inhibitor, AZM as prototype, in an orthotopic mouse xenograft model and a patient-derived xenograft model of PCa with activated mitochondrial biogenesis. This study uses state-of-the-art platforms including reverse phase protein array, stable isotope-resolved metabolomics, total internal reflection fluorescence microscopy with Imaris software, TEMPOL-enhanced MRI imaging, and a high resolution O2k-FluoRespirometer. The proposed studies are expected to uncover novel molecular insights by which concurrently targeting mitochondrial redox capacity and mitochondrial biogenesis improve RT efficacy in the treatment of RR-PCa.

摘要（R01CA251663） 放射治疗（RT）被广泛用于治疗局部前列腺癌（PCA）。但是，癌细胞经常 通过未知的机制发展对RT的抗性，导致癌症复发。为了改善RT， 迫切需要发现导致细胞变得抗性的细胞事件。我们以前证明了 PCA异质性，特别是在具有丰富线粒体亚群的前列腺癌中，经常生存 RT之后（称为耐辐射前列腺癌或RR-PCA）后再生。线粒体质量的升高， 在RR-PCA细胞中获得数量，活性氧（ROS）和生物发生标记。我们进一步 证明线粒体生物发生调节剂TFAM（转录因子A， 线粒体），显着恢复了RR-PCA细胞对RT的敏感性。因此，我们的总体假设是 通过ROS，RT激活的线粒体生物发生是一种采集机制，可在 RT，在拟议的研究中将进行严格检查的前提。 ROS已知直接 通过融合，裂变，线粒体和生物发生来间接调节线粒体稳态。我们筛选了 FDA批准的药物以寻找无毒细胞的化合物，并具有提升的能力 PCA细胞中线粒体氢（MTH2O2）的水平，同时阻断线粒体蛋白翻译。 我们发现大花生素抗生素Azithromycin（AZM）是具有有效原型化合物 这两个属性。我们进一步证明，与RT结合的AZM可增强PCA细胞的死亡 与仅AZM或RT相比，大量的线粒体亚群。因此，我们建议推进我们的发现 并确定有效抑制后辐照癌细胞存活的机制，以改善RT 功效。具体目的是：1）定义RT激活线粒体的分子机制 生物发生促进具有丰富线粒体的PCA细胞的细胞存活和代谢适应 体外和体内； 2）确定是否将MTH2O2超载到靶向固有的线粒体和RT剂量 线粒体在RT获得的线粒体中阻断线粒体蛋白翻译时的线粒体增强 RR-PCA细胞的放射敏性，3）使用MTH2O2发电机和线粒体蛋白改善RT 在原位小鼠异种移植模型和患者衍生的异种移植物中，翻译抑制剂作为原型的AZM作为原型 具有活化线粒体生物发生的PCA模型。本研究使用了最新平台 反相蛋白阵列，稳定的同位素分辨代谢组学，总内反射荧光 带有Imaris软件，Tempol增强的MRI成像和高分辨率O2K-Fluorespremeter计的显微镜。 预计拟议的研究将揭示新的分子见解，通过这些见解 线粒体氧化还原能力和线粒体生物发生提高了RR-PCA治疗的RT功效。