Noninvasive monitoring of brain tumor development with focused ultrasound andextracellular vesicles

项目摘要 多形性胶质母细胞瘤是最常见的原发性脑肿瘤，也是最致命的人类癌症之一。 早期诊断和敏感的治疗监测仍然是治疗这种疾病的主要挑战。 肿瘤发展和治疗干预的监测在很大程度上依赖于临床评估和MRI。 然而，临床检查和MRI都是不敏感的疾病状态的措施。例如MRI 分辨率被限制在毫米的数量级，这意味着在肿瘤可以被切除之前有显著的延迟。 检测到虽然活组织检查是有价值的，但它们是侵入性的，可能导致严重的发病率。侵入性较小 迫切需要早期诊断和治疗监测平台。在过去的二十年里， 细胞外囊泡已经成为不同生物学过程的重要调节剂， 包括脑癌在内的多种病理。这些囊泡是一类膜包封的纳米颗粒 具有多种生物学功能、诊断潜力和治疗应用。这些囊泡通常是 尺寸小于1000 nm，并且在癌症患者中以高达1000个囊泡/mL的浓度存在于血液中。他们 已被证明含有肿瘤特异性核酸、蛋白质和脂质货物，并且表现出高度的特异性。 富含癌症特异性miRNA。细胞外囊泡作为循环生物标志物是最有前途的生物标志物之一， 癌症研究中的新诊断和治疗范例。细胞外囊泡包括两个主要的断裂- 不同的大小，货物和功能作用的离子（外泌体和微粒）。这两个部分都可以用作 用于诊断、分期和监测治疗干预的潜在生物标志物。的主要限制 使用细胞外囊泡诊断和监测脑肿瘤的比例相对较低， MOR特异性细胞外囊泡，在血浆样品中，特别是大尺寸细胞外囊泡部分（MI-1）， 由于血脑屏障（BBB）和血肿瘤屏障（BTB）的存在，为了解决这个 挑战，我们将使用超声脉冲结合循环微泡暂时破坏这些 屏障和独特的方法来分析所有细胞外囊泡部分的存在，包括较大的尺寸 血浆中的微粒部分。这个过程，这可以使用超声设备进行交流， 精确和安全地聚焦超声波束穿过人类头骨，作为一种非侵入性的 和靶向破坏BBB/BTB用于药物递送的方法。这里将使用它来增加 细胞外囊泡在患者血浆中的大尺寸部分。结合肿瘤特异性 细胞外囊泡在血浆样品中，这项技术可以是一个强大的工具， 脑肿瘤的治疗-一种非侵入性的活检。为了实现这一目标，我们将进行广泛的研究，在亩- rine胶质瘤模型，以优化该程序并在不同肿瘤阶段对其进行评估。如果前- 如果实验成功，我们将有令人信服的证据，可能导致人体试验。

Project Summary Glioblastoma multiforme is the most common primary brain tumor and one of the deadliest of human cancers. Early diagnosis and sensitive therapeutic monitoring remain major challenges in the treatment of this disease. Monitoring of tumor development and therapeutic interventions largely relies on clinical evaluation and MRI. However, both clinical examination and MRI are insensitive measures of disease status. For example, MRI resolution is limited to the order of millimeters, which translates to a significant delay before a tumor can be detected. While biopsies are valuable, they are invasive and can result in significant morbidity. Less invasive platforms for early diagnostic and therapeutic monitoring are desperately needed. Within the past two decades, extracellular vesicles have emerged as important regulators of a diverse range of biological processes in dif- ferent pathologies including brain cancer. These vesicles are a family of membrane-enveloped nanoparticles with diverse biological function, diagnostic potential, and therapeutic applications. These vesicles are typically <1000 nm in size and are present in blood at concentrations of up to 1000 vesicles/mL in cancer patients. They have been shown to contain tumor-specific nucleic acids, proteins, and lipid cargoes and appear highly en- riched with cancer-specific miRNA. Extracellular vesicles as circulating biomarkers are one of the most promis- ing new diagnostic and therapeutic paradigms in cancer research. Extracellular vesicles include two major frac- tions (exosomal and microparticles) differing by size, cargoes, and functional role. Both fractions can serve as potential biomarkers for diagnosis, staging, and monitoring of therapeutic interventions. A major limitation of using extracellular vesicles for diagnosis and monitoring of brain tumors is the relatively low proportion of tu- mor-specific extracellular vesicles, in plasma samples in particular large size extracellular vesicles fraction (mi- croparticles) due to the presence of blood-brain barrier (BBB) and blood-tumor barrier (BTB). To address this challenge, we will use ultrasound bursts combined with circulating microbubbles to temporarily disrupt these barriers and unique approach to analyze a presence of all extracellular vesicles fractions including larger size microparticle fraction in the plasma. This procedure, which can be performed using ultrasound devices that ac- curately and safely focus an ultrasound beam through the human skull, has a great potential as a noninvasive and targeted method to disrupt BBB/BTB for drug delivery. Here will instead use it to increase the presence of extracellular vesicles large-size fractions in the patient's plasma. Combined with analysis of the tumor-specific extracellular vesicles in plasma samples, this technology could be a powerful tool for both the diagnosis and treatment of brain tumors – a noninvasive biopsy. To reach this goal, we will perform extensive studies in mu- rine glioma models to optimize the procedure and evaluate it during different tumor stages. If the proposed ex- periments are successful, we will have compelling evidence that may lead to human trials.