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Inhibition of Autophagy Enhances Anti-Angiogenic Efficacy in Intracranial Glioma

抑制自噬增强颅内胶质瘤的抗血管生成功效

基本信息

批准号：
8450070
负责人：
MARTIN M PIKE
金额：
$ 15.74万
依托单位：
OREGON HEALTH & SCIENCE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-04-01 至 2016-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8450070
关键词：
Antimalarials Apoptosis Apoptotic Autophagocytosis Autophagosome Biological Markers Blood - brain barrier anatomy Blood Vessels Blood Volume Bolus Infusion Cell Death Cell Death Induction Cell Proliferation Cell Survival Cells Cerebrovascular Circulation Cerebrum Clinical Degradation Pathway Dose Drug Combinations Exposure to Flow Cytometry Glioblastoma Glioma Glucose Goals Growth Human Hypoxia Hypoxia Inducible Factor Image Immunoblotting Immunohistochemistry Implant In Vitro Lead Light Link Magnetic Resonance Imaging Malignant Glioma Maps Measurement Measures Metabolic Metabolic stress Methods Microtubule-Associated Proteins Modality Modeling Molecular Molecular Target Monitor Morbidity - disease rate Mus Necrosis Neoplasms in Vascular Tissue Nude Mice Nutrient Organelles Oxygen Pathway interactions Perfusion Permeability Play Predisposition Process Proteins Quinacrine Resolution Role Staging Stress Testing Therapeutic Tissues Treatment Efficacy Treatment outcome Tumor Angiogenesis Tyrosine Kinase Inhibitor Vascular Permeabilities Work angiogenesis combinatorial cytotoxic density deprivation design drug efficacy imaging modality improved in vivo indexing inhibition of autophagy inhibitor/antagonist macromolecule mortality mouse model neoplastic cell novel novel therapeutics outcome forecast prevent receptor research study response synergism transcription factor treatment strategy tumor tumor growth

项目摘要

DESCRIPTION (provided by applicant): Malignant gliomas are highly aggressive, invasive, and vascular tumors for which clinical prognosis remains extremely poor. Gliomas are highly vascular, but current anti-angiogenic therapy (AAT) induces only a transitory clinical benefit. Evidence suggests that gliomas adapt to AAT, by activation of alternative angiogenic pathways and increased invasion. We hypothesize that AAT can be combined with molecular targeting (AAT+MT), to disrupt the adaptive mechanisms that enable tumors to survive AAT alone. A key target is autophagy, a degradative pathway that may enable tumor cell survival during hypoxic/nutrient stress. Autophagy prevents toxic protein and organelle accumulation and provides energy and biosynthetic substrates. Autophagic pathways are linked to pathways controlling cell death, and autophagic inhibition may induce cell death. We have developed a comprehensive dual bolus perfusion MRI method that enables us to visualize tumor perfusion and growth in vivo, in mice with intracranial gliomas. This method first utilizes dynamic contrast enhanced (DCE) MRI to provide maps of Ktrans, an index of vascular permeability. Then dynamic susceptibility contrast MRI (DSC-MRI) is done to measure cerebral blood flow (CBF). This dual bolus method suggests that AAT+MT therapy with the anti-angiogenic receptor tyrosine kinase inhibitor Cediranib (AstraZeneca) and the autophagy inhibitor quinacrine can have synergistic cytotoxic effects. Quinacrine is an anti-malarial agent which interrupts autophagosome function and has excellent blood brain barrier permeability. Preliminary results show anti-angiogenic/anti-tumor efficacy in vivo with resulting extended survival. Specific Aim 1 will characterize the dose-dependent in vitro responses of mouse (4C8) and human (U87) glioma cells to Cediranib and quinacrine, singly and in combination, under normal and oxygen glucose deprived conditions. These experiments will test hypotheses that a) hypoxic/nutrient stress plays a role in the synergism between Cediranib and quinacrine; b) induction of autophagy occurs with Cediranib under conditions of hypoxic/nutrient stress; and c) combined late-stage autophagic inhibition via quinacrine effectively induces autophagosome accumulation and tumor cell death. Specific Aim 2 will investigate the effects of single and combined Cediranib and quinacrine treatment in vivo, employing the intracranial mouse 4C8 and U87 malignant glioma models. These experiments test the hypothesis that combined administration of the two agents results in a synergistic anti-vascular/anti-tumor therapeutic efficacy. Dual bolus DCE/DSC MRI will be used to assess tumor growth and angiogenesis. Immunohistochemistry will be used ex vivo, to quantify tumor cell apoptosis, necrosis, autophagy, hypoxia and microvessel density. Both Specific Aims will employ immunoblot with cell and tissue lysates to quantify cellular markers and investigate underlying mechanisms. These preliminary studies are required to justify more detailed studies of the drug efficacy and the mechanisms of AAT+MT in treating malignant glioma, defined in a R01-type application.

描述（由申请人提供）：恶性胶质瘤是高度侵袭性、侵袭性和血管性肿瘤，临床预后极差。神经胶质瘤是高度血管化的，但目前的抗血管生成治疗（AAT）仅诱导短暂的临床获益。有证据表明，胶质瘤通过激活替代血管生成途径和增加侵袭来适应AAT。我们假设AAT可以与分子靶向（AAT+MT）相结合，以破坏使肿瘤能够单独存活的适应性机制。一个关键的目标是自噬，这是一种降解途径，可以使肿瘤细胞在缺氧/营养应激期间存活。自噬防止有毒蛋白质和细胞器积累，并提供能量和生物合成底物。自噬途径与控制细胞死亡的途径相关，自噬抑制可诱导细胞死亡。我们已经开发了一种全面的双团注灌注MRI方法，使我们能够可视化肿瘤灌注和生长在体内，在小鼠颅内胶质瘤。该方法首先利用动态对比增强（DCE）MRI来提供Ktranss图，Ktranss是血管渗透性的指标。然后进行动态磁敏感对比MRI（DSC-MRI）测量脑血流量（CBF）。这种双推注方法表明，AAT+MT疗法与抗血管生成受体酪氨酸激酶抑制剂西地尼布（阿斯利康）和自噬抑制剂奎纳克林可以具有协同细胞毒性作用。奎纳克林是一种抗疟疾药物，可阻断自噬体功能，并具有良好的血脑屏障通透性。初步结果显示体内抗血管生成/抗肿瘤功效，从而延长存活期。具体目标1将表征在正常和氧葡萄糖剥夺条件下，小鼠（4C 8）和人（U87）胶质瘤细胞对西地尼布和奎纳克林（单独和组合）的剂量依赖性体外应答。这些实验将测试以下假设：a）缺氧/营养应激在西地尼布和奎纳克林之间的协同作用中起作用; B）在缺氧/营养应激条件下西地尼布发生自噬的诱导;和c）通过奎纳克林的组合晚期自噬抑制有效地诱导自噬体积累和肿瘤细胞死亡。具体目标2将采用颅内小鼠4C 8和U87恶性胶质瘤模型研究西地尼布和奎纳克林单独和组合治疗的体内作用。这些实验测试了两种药剂的组合施用导致协同抗血管/抗肿瘤治疗功效的假设。双团注DCE/DSC MRI将用于评估肿瘤生长和血管生成。将使用免疫组织化学离体定量肿瘤细胞凋亡、坏死、自噬、缺氧和微血管密度。两个特定目标将采用细胞和组织裂解物的免疫印迹来定量细胞标志物并研究潜在机制。需要这些初步研究来证明AAT+MT治疗恶性胶质瘤的药物疗效和机制的更详细研究是合理的，在R 01型申请中定义。