Altered mitochondria-ER signaling as a cause of chemotherapy resistance

线粒体-ER 信号传导的改变是化疗耐药的一个原因

基本信息

批准号：
9178264
负责人：
MICHAEL D HOGARTY
金额：
$ 19.33万
依托单位：
CHILDREN'S HOSP OF PHILADELPHIA
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-07-01 至 2018-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9178264
关键词：
Accounting Aftercare Apoptotic Attenuated Biochemical Biological Assay Bypass Calcium Calcium Signaling Cells Cessation of life Child Clinic Clinical Clinical Treatment Combined Modality Therapy Competence Coupling DNA Damage Data Defect Development Diabetes Mellitus Diagnosis Disease Progression Disease Resistance Distal Drug Targeting Drug resistance Endoplasmic Reticulum Etiology Fluorescence Microscopy Functional disorder GRP75 Genes Genetic Goals Health Human ITPR1 gene Intervention Knowledge Malignant Neoplasms Measures Membrane Mitochondria Mitochondrial Matrix Modality Molecular Multi-Drug Resistance Mutagens Mutate Mutation Nerve Degeneration Neuroblastoma Oncogenic Organelles Outcome P-Glycoprotein Patients Pediatric Oncology Group Pharmaceutical Preparations Pharmacotherapy Phenotype Phosphotransferases Play Process Radiation therapy Reading Regulation Relapse Reporter Research Research Infrastructure Resistance Resources Role Signal Transduction Stimulus Stress TP53 gene Techniques Testing Therapeutic Time Treatment Failure Tumor Cell Line Work Xenograft procedure base cancer care cancer cell cancer therapy chemoradiation chemotherapy defined contribution human mortality improved improved outcome in vivo inhibitor/antagonist innovation kinase inhibitor mitochondrial dysfunction model development molecular imaging novel prevent release of sequestered calcium ion into cytoplasm resistance mechanism response stressor therapy development therapy resistant tool tumor tumor progression

项目摘要

Project Summary Most patients who die from cancer have progression of therapy resistant tumors. Emergent resistance to diverse treatments with distinct mechanisms of activity, termed multidrug resistance, is the greatest barrier to cure yet its causes remain largely unknown. A role for cancer mitochondria in therapy resistance has been sought since these organelles integrate stress and survival signals to determine cell fate. Indeed, most effective cancer therapies induce stress signals sufficient to activate mitochondrial apoptotic signaling, while alterations that repress this process are selected for during tumor progression. To interrogate this directly we optimized an innovative assay in which functional mitochondria are isolated from cancer cells and selectively exposed to tBid and/or Bim, the death stimuli delivered to mitochondria in response to most therapeutic stressors. This provides a read-out of their relative stress sensitivity. We use this tool to study resistance in neuroblastoma, a highly lethal cancer that often completely regresses in response to chemoradiotherapy before subsequently relapsing as multidrug resistant disease. We created a national infrastructure to derive tumor cell lines and patient-derived xenografts from the same patients both at the time of initial diagnosis (before therapy) and again at the time of relapse after treatment. These near-isogenic tumor pairs provide a unique resource as the post-relapse tumors manifest profound multidrug resistance that has been selected for during the course of intensive multimodality treatment. Applying our mitochondrial profiling technique to these tumors enabled the discovery that mitochondria derived from post-relapse therapy resistant tumors have severely blunted apoptotic signaling in response to tBid and Bim in comparison with therapy sensitive tumors. The objective of our work here is to identify the mitochondrial determinants of this therapy resistance. Our central hypothesis based on our preliminary data is that a loss of physical tethering between endoplasmic reticulum and mitochondria is the principal driver of multidrug resistance. ER mitochondria tethers (also termed mitochondria-associated ER membranes, or MAMs) form IP3R/GRP75/VDAC-enriched domains to transfer calcium to mitochondria, and their absence attenuates apoptotic signaling. To test this we will quantify ER- mitochondria contacts in tumors with chemotherapy and kinase inhibitor resistance, manipulate tethering using genetic and biochemical approaches and assess its impact on mitochondrial activities and drug resistance (Aim 1), and define the role calcium plays in this phenotype (Aim 2). While this novel resistance mechanism provides a survival bias downstream of diverse stressors it is not exclusive to other resistance mechanisms. Of note, altered ER-mitochondria tethering has been implicated in diabetes and neurodegeneration as well so its deregulation has broad relevance to human health. The outcomes of these Aims will reveal the contributions of this ER-mitochondria phenotype to cancer therapy resistance, a novel model for the development of tools to measure this, and the identification of therapeutic opportunities to revert resistance.

项目摘要大多数死于癌症的患者都具有抗治疗肿瘤的进展。紧急的抵抗力具有不同的活动机制的多种处理方法，称为多药耐药性，是最大的障碍治愈但其原因在很大程度上尚不清楚。癌症线粒体在耐药性中的作用是由于这些细胞器会整合应力和存活信号以确定细胞命运。确实，大多数有效的癌症疗法会诱导足以激活线粒体凋亡信号的应力信号，而在肿瘤进展过程中选择了抑制此过程的变化。直接询问我们优化了一种创新的测定法，其中功能性线粒体从癌细胞中分离出来，并有选择地暴露于TBID和/或BIM，死亡刺激响应于大多数治疗方法。压力源。这提供了他们相对压力敏感性的读出。我们使用此工具来研究阻力神经母细胞瘤，一种高度致命的癌症，通常对化学放射疗法完全消退随后作为多药抗性疾病复发。我们创建了一个国家基础设施来得出初始诊断时，来自同一患者的肿瘤细胞系和患者衍生的异种移植物（治疗前），在治疗后复发时再次。这些近乎异构的肿瘤对提供了独特的资源，因为后肿瘤表现出已选择的深刻多药电阻在强化多模式治疗过程中。将我们的线粒体分析技术应用于这些技术肿瘤得出的发现，即从后释放疗法抗肿瘤衍生出的线粒体具有与治疗敏感肿瘤相比，对TBID和BIM的响应严重钝化的凋亡信号传导。我们在这里工作的目的是确定这种耐药性的线粒体决定因素。我们的基于我们的初步数据的中心假设是内质之间的物理束缚损失网状和线粒体是多药耐药性的主要驱动力。 er线粒体系数（也称为线粒体相关的ER膜，或MAMS）形成IP3R/GRP75/VDAC富含域的形式转移钙至线粒体，其缺失会减弱凋亡信号传导。为了测试这一点，我们将量化肿瘤中的线粒体接触，具有化学疗法和激酶抑制剂耐药性，使用束缚遗传和生化方法并评估其对线粒体活动和耐药性的影响（AIM 1），并定义钙在此表型中的作用（AIM 2）。而这种新颖的阻力机制在不同的压力源下游提供生存偏见，它并不是其他抵抗机制的独特偏见。的请注意，ER-线粒体绑扎的改变也与糖尿病和神经变性有关放松管制与人类健康具有广泛的相关性。这些目标的结果将揭示贡献癌症治疗耐药性的ER-线粒体表型，这是一种开发工具的新型模型衡量这一点，并确定恢复抵抗的治疗机会。