(PQ5) Imaging mitochondrial heterogeneity in LKB1 mutant lung cancer

(PQ5) LKB1 突变肺癌线粒体异质性成像

• 批准号: 10063382
• 负责人: David B Shackelford
• 金额: $ 7.83万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-01 至 2022-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10063382
• 关键词: Adenosine Monophosphate; Anabolism; Anions; Antibodies; Apoptosis; Apoptotic; Area; Avidity; Biochemical; Biology; Cancer Patient; Cancer cell line; Cardiolipins; Cell Line; Chemicals; Complex; Coupled; Coupling; Data; Defect; Development; Diagnosis; Dissection; Electron Microscopy; Exposure to; Genetic; Genetically Engineered Mouse; Genus Hippocampus; Goals; Health; Heterogeneity; Homeostasis; Human; Image; In Vitro; Inner mitochondrial membrane; Lead; Link; Longitudinal Studies; Lung Neoplasms; Malignant Neoplasms; Malignant neoplasm of lung; Maps; Measurement; Measures; Mediating; Membrane Potentials; Mitochondria; Modeling; Molecular; Morphology; Mus; Mutate; Mutation; Neoplasm Metastasis; Nodule; Non-Small-Cell Lung Carcinoma; Outer Mitochondrial Membrane; Pathway interactions; Patients; Phosphotransferases; Physiological; Population; Positron-Emission Tomography; Protein Tyrosine Phosphatase; Public Health; RNA Interference; Regulation; STK11 gene; Signal Pathway; Stress; Structure; Testing; Transmission Electron Microscopy; Tumor Suppressor Genes; Tumor Suppressor Proteins; Work; Xenograft procedure; field study; imaging detection; improved outcome; in vivo; inhibitor/antagonist; lung development; lung tumorigenesis; microscopic imaging; mitochondrial membrane; mutant; neoplastic cell; new therapeutic target; novel; novel therapeutics; radiotracer; restoration; sensor; tumor; tumor progression; voltage

ABSTRACT The goal of this study is to utilize PET imaging in GEMMs to perform a mechanistic study of mitochondrial heterogeneity following inactivation of the LKB1/AMPK signaling pathway during lung tumor development. LKB1 functions as a master kinase that regulates cellular energetics and mitochondrial function through activation of the adenosine monophosphate activated kinase (AMPK) that is frequently mutated in cancer. LKB1 mutations lead to inactivation of the AMPK signaling pathway resulting in severe defects in cellular energetics and mitochondrial homeostasis. This results in highly variable mitochondrial pools within human and mouse tumors that consist of numerous atypical mitochondria of differing size, morphology and function that we define as mitochondrial heterogeneity,. However, little is understood at a physiological or mechanistic level how mitochondrial heterogeneity resulting from LKB1 inactivation impact lung tumorigenesis or therapy. We examined mitochondrial structural and functional heterogeneity in lung tumors in vivo by coupling electron microscopy (EM) and positron emission tomography (PET) imaging of Lkb1-/- genetically engineered mouse models (GEMMs). Using a voltage sensitive mitochondrial specific radiotracer [18F]-Fluorobenzyl- triphenylphosphonium (FTP) we are able to measure mitochondrial membrane potential (∆Ψ) in lung tumors by PET imaging. FTP PET imaging identified lung tumor populations with heterogeneous mitochondrial activity in vivo. Additionally, mitochondrial defects sensitize LKB1-/- tumor cells to undergo mitochondrial outer membrane permeabilization (MOMP) and apoptosis and we discovered the LKB1/AMPK pathway is a potential regulator of MOMP and apoptosis through voltage dependent anion 1 (VDAC1). Lastly, as a result of a synthetic lethal chemical screen, we identified protein tyrosine phosphatase mitochondria 1 (PTPMT1), a key regulator of cardiolipin biosynthesis and mitochondrial integrity as a novel therapeutic target in LKB1-/- lung cancer. We hypothesize that inactivation of the LKB1 tumor suppressor induces heterogeneity in mitochondrial structure and function that drives lung tumor development. To test this hypothesis we will integrate PET and EM imaging of Lkb1-/- GEMMs of lung cancer to longitudinally study mitochondrial heterogeneity at distinct stages of lung tumor development. In Aim1 we will use FTP PET imaging to map mitochondrial heterogeneity and dynamics in vivo during lung tumorigenesis following LKB1 loss. In Aim 2 we will identify the molecular mechanisms by which the LKB1/AMPK pathway regulates the mitochondrial outer membrane. In Aim 3 perform an in vivo dissection of the PTPMT1-cardiolipin pathway in LKB1-/- lung tumors. We propose first-in- field studies that will advance our fundamental understanding of mitochondrial biology and the impact of mitochondrial heterogeneity has on promoting lung tumorigenesis. The proposed work has relevance to human health in the areas of PET imaging based detection diagnosis of lung cancer as well as the development of new therapies to improve outcomes for lung cancer patients.

摘要 本研究的目的是利用PET成像在GEMM进行线粒体的机制研究， 在肺肿瘤发展过程中LKB 1/AMPK信号通路失活后的异质性。 LKB 1作为一种主激酶发挥作用，通过以下途径调节细胞能量学和线粒体功能： 腺苷一磷酸激活激酶（AMPK）的激活，其在癌症中经常突变。 LKB 1突变导致AMPK信号通路失活，导致细胞凋亡严重缺陷。 能量学和线粒体稳态。这导致了人类和哺乳动物体内高度可变的线粒体库， 小鼠肿瘤由许多不同大小、形态和功能的非典型线粒体组成， 我们定义为线粒体异质性。然而，在生理学或机械学水平上， LKB 1失活导致的线粒体异质性如何影响肺肿瘤发生或治疗。我们 用电子偶联技术检测了肺肿瘤中线粒体结构和功能的异质性 Lkb 1-/-基因工程小鼠的显微镜（EM）和正电子发射断层扫描（PET）成像 模型（GEMM）。使用电压敏感的线粒体特异性放射性示踪剂[18F]-氟苄基- 三苯基磷（FTP），我们能够测量肺肿瘤中的线粒体膜电位（线粒体膜电位）， PET成像。FTP PET成像确定了肺肿瘤患者中具有异质性线粒体活性的人群， vivo.此外，线粒体缺陷使LKB 1-/-肿瘤细胞敏感， 膜透化（MOMP）和细胞凋亡，我们发现LKB 1/AMPK途径是一个潜在的 通过电压依赖性阴离子1（VDAC 1）调节MOMP和凋亡。最后，由于A 合成致死化学筛选，我们确定了蛋白酪氨酸磷酸酶线粒体1（PTPMT 1），一个关键 心磷脂生物合成和线粒体完整性的调节剂作为LKB 1-/-肺的新治疗靶点 癌我们假设LKB 1肿瘤抑制因子的失活诱导了线粒体内的异质性。 结构和功能，驱动肺肿瘤的发展。为了验证这一假设，我们将整合PET和 肺癌Lkb 1-/- GEMMs的EM成像以纵向研究不同时间的线粒体异质性 肺肿瘤发展的阶段。在Aim 1中，我们将使用FTP PET成像来绘制线粒体异质性 和LKB 1丢失后肺肿瘤发生过程中的体内动力学。在目标2中，我们将确定 LKB 1/AMPK途径调节线粒体外膜的机制。目标3 在LKB 1-/-肺肿瘤中进行PTPMT 1-心磷脂途径的体内解剖。我们建议先- 实地研究，这将促进我们对线粒体生物学的基本理解， 线粒体异质性对肺肿瘤的发生有促进作用。拟议的工作与以下方面有关： 在基于PET成像的肺癌检测诊断以及 开发新的治疗方法，以改善肺癌患者的预后。