MRgFUS-enabled non-invasive interrogation of malignant glioma via circulating tumor DNA

项目摘要 染色体缺失和DNA突变的分子指纹在临床上越来越重要。 胶质母细胞瘤（GBM）是最常见和致命的原发性成人脑肿瘤。 虽然肿瘤DNA的临床分析必须依赖于神经外科标本，但非侵入性 通过循环肿瘤DNA（ctDNA）的液体活组织检查的检测具有彻底改变检测的潜力 以及监测这些侵袭性、异质性和治疗抗性肿瘤。尽管几 研究小组在非中枢神经系统（CNS）肿瘤患者中检测到ctDNA， 中枢神经系统内的脑肿瘤可能会限制ctDNA等分子通过血脑屏障 （BBB）。一种新的非侵入性技术，以破坏血脑屏障是磁共振成像引导的重点 超声（MRgFUS）。MRgFUS可以安全地将超声能量以高精度输送到完整的颅骨上 和准确性，并被FDA批准用于使用高能量治疗某些神经退行性疾病 热损伤MRgFUS介导的BBB破坏在相对低的能量设置下完成， 用于振荡循环的微泡，扰动和暂时破坏血脑屏障。项目组 正在领导美国临床试验，研究脑癌患者中MRgFUS介导的BBB破坏， 已经成为实体瘤中ctDNA灵敏和特异性检测的先驱。因此，委员会认为， 我们建议研究MRgFUS通过肿瘤的CNS外释放来实现脑癌的液体活检 DNA.我们的总体假设是，使用MRgFUS定位于特定脑肿瘤区域的BBB破坏将 将肿瘤区域特异性DNA释放到循环中，并且这种ctDNA将使用我们的高度敏感的 DNA测序技术。我们进一步预测，超声设置可以进一步调整和优化 以保持安全性并增加ctDNA的释放以提高检测/诊断产率。我们将测试这个 在两个具体目标的假设：在目的1，我们将研究FUS触发的神经胶质瘤释放的动力学 DNA进入先进的，忠实的临床前GBM大鼠模型的血流，并确定最佳设置 和肿瘤DNA释放的时间，同时保持安全性。在目标2中，我们建议评估 已入组MRgFUS介导的BBBD的脑肿瘤患者血液中的肿瘤特异性DNA 由我们团队领导的临床试验。成功完成工作，确定MRGFUS的潜力 能够对GBM进行非侵入性活检，这将从根本上推进人类肿瘤的诊断和监测。 脑癌

Project Summary Molecular fingerprinting of chromosomal deletions and DNA mutations is increasingly important in the clinical management of patients with glioblastoma (GBM) – the most common and deadly primary adult brain tumor. While clinical analyses of tumor DNA have to this point relied on neurosurgical specimens, non-invasive detection through liquid biopsy of circulating tumor DNA (ctDNA) has the potential to revolutionize the detection and monitoring of these aggressive, heterogeneous, and treatment resistant neoplasms. Although several groups have detected ctDNA in patients with non-central nervous system (CNS) tumors, the protected location of brain tumors within the CNS likely limits the passage of molecules like ctDNA through the blood brain barrier (BBB). A new non-invasive technology to disrupt the BBB is magnetic resonance imaging-guided focused ultrasound (MRgFUS). MRgFUS can safely deliver ultrasound energy across the intact skull with high precision and accuracy, and is FDA-approved for the treatment of certain neurodegenerative conditions using high energy thermal lesioning. MRgFUS-mediated BBB disruption is accomplished with relatively low energy settings which are used to oscillate circulating microbubbles, perturbing and temporarily disrupting the BBB. The project team is leading the US clinical trials investigating MRgFUS-mediated BBB disruption in brain cancer patients, and have been pioneers in the sensitive and specific detection of ctDNA in the setting of solid tumors. Accordingly, we propose investigating MRgFUS to enable liquid biopsy of brain cancer through extra-CNS release of tumor DNA. Our overall hypothesis is that BBB disruption localized to specific brain tumor regions using MRgFUS will release tumor region-specific DNA into the circulation and this ctDNA will be detectable using our highly sensitive DNA sequencing technology. We further predict that the ultrasound settings can be further tuned and optimized to maintain safety and increase release of ctDNA to improve detection/diagnostic yield. We will test this hypothesis in two specific aims: In Aim 1, we will investigate the dynamics of FUS-triggered release of glioma DNA into the blood stream in advanced, faithful pre-clinical GBM rat models and determine the optimal settings and timing of tumor DNA release while maintaining safety. In Aim 2, we propose to assess the presence of tumor-specific DNA in the blood of brain tumor patients who will be already enrolled in MRgFUS-mediated BBBD clinical trials lead by our team. Successful completion of the work with establish the potential for MRgFUS enabled, non-invasive biopsy of GBM, which would radically advance the diagnosis and monitoring of human brain cancer.