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

基本信息

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
项目类别：
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

项目摘要

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) 广泛用于治疗局限性前列腺癌 (PCa)。然而，癌细胞常常通过未知机制对放疗产生耐药性，导致癌症复发。为了提高RT，有迫切需要发现导致细胞产生耐药性的细胞事件。我们之前证明了 PCa 异质性，特别是在具有丰富线粒体亚群的前列腺癌中，通常能够幸存并在放疗后重新生长（称为抗辐射前列腺癌，或 RR-PCa）。线粒体质量升高，数量、活性氧 (ROS) 和生物发生标记物是在 RR-PCa 细胞中获得的。我们进一步证明线粒体生物发生调节因子 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 RT 激活的线粒体生物发生（通过 ROS）是一种驱动 PCa 存活后的获得机制。 RT，这一前提将在拟议的研究中接受严格的审查。众所周知，ROS 可以直接通过融合、裂变、线粒体自噬和生物发生间接调节线粒体稳态。我们筛选了 FDA 批准的药物正在寻找对正常细胞无毒且能够提高细胞活性的化合物 PCa 细胞中线粒体过氧化氢 (mtH2O2) 的水平，同时阻断线粒体蛋白翻译。我们发现阿奇霉素（AZM）是一种大环内酯类抗生素，是一种有效的原型化合物，具有两个属性。我们进一步证明 AZM 与 RT 结合可增强 PCa 细胞的死亡与单独使用 AZM 或 RT 相比，线粒体亚群丰富。因此，我们建议推进我们的发现并确定有效抑制辐射后癌细胞存活的机制，以提高 RT 功效。具体目标是：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，无论是在体外和体内； 2) 确定 mtH2O2 是否超载以靶向固有线粒体和 RT 获得性线粒体同时阻断 RT 获得性线粒体中线粒体蛋白翻译增强 RR-PCa 细胞的放射敏感性，以及 3) 使用 mtH2O2 发生器和线粒体蛋白改善 RT 翻译抑制剂，AZM作为原型，在原位小鼠异种移植模型和患者来源的异种移植模型中具有激活线粒体生物发生的 PCa 模型。这项研究使用了最先进的平台，包括反相蛋白阵列、稳定同位素代谢组学、全内反射荧光采用 Imaris 软件的显微镜、TEMPOL 增强的 MRI 成像和高分辨率 O2k-Fluo 呼吸计。拟议的研究预计将揭示新的分子见解，同时靶向线粒体氧化还原能力和线粒体生物发生可提高 RT 治疗 RR-PCa 的疗效。