Modeling the Glioblastoma Microenvironment to Uncover Progression Mechanisms and Therapeutic Targets

在几乎所有形式的人类癌症中，坏死的发展与癌症的发生密切相关。 恶性进展坏死是否加速进展或主要是被动的 仍然是一个悬而未决的问题，但建模这些事件，以建立机制， 动物的治疗弱点一直是一个挑战。在胶质母细胞瘤（GBM; WHO IV级），最恶性的原发性脑肿瘤，快速，放射状生长阶段， 迅速导致死亡之前总是会出现中央坏死。 虽然GBM的遗传改变是非常详细的，但GBM的生物学特性， 由于他们的收购，并导致这一加速增长阶段，需要更深入的 调查肿瘤微环境（TME）在肿瘤发生后发生了显著变化。 坏死的开始，来自浸润细胞的片状生长，具有相对恒定的 一个高度复杂和不断发展的三维微系统的生长特性， 不同的细胞类型和空间隔离的信号网络。更好地了解 动态的时空变化，促进进步，我们建议， 先进的小鼠模型，密切平行于这些事件在人类胶质瘤，因为许多 GBM的小鼠模型没有坏死。我们开发了一种新的方法， 在体内高级别胶质瘤内的坏死，并将研究TME重组及其 使用多光子显微术对胶质瘤生长真实的时间影响。如翻译 应用程序，我们将展示如何缺氧和坏死促进富集 神经胶质瘤干细胞（GSC）在其周围坏死的小生境，并导致戏剧性的涌入， 肿瘤相关巨噬细胞（TAM），其数量增加超过10倍， 人类疾病我们提出了两个遗传特征的患者源性GBM 在小鼠中生长的具有人源化免疫细胞的异种移植物，以及 免疫活性RCAS/tv-a模型，并将确定如何拮抗这些 过程影响疾病进展和结果。我们的初步数据和 文献表明坏死前和坏死神经胶质瘤之间存在实质性差异， 关于GSC和TAM富集及其对生物特性的影响，但 机制和演变尚未深入研究，在很大程度上是由于 缺乏可靠的动物模型。我们的模型将捕捉神经胶质瘤的生长动力学， GSC富集和TAM流入，并促进治疗的发展， 对抗这些机制以改善结果。

In nearly all forms of human cancer, the development of necrosis is tightly linked with malignant progression. Whether necrosis accelerates progression or is largely passive remains an open question, yet modeling these events to establish mechanisms and therapeutic vulnerabilities in animals has been challenging. In glioblastoma (GBM; WHO grade IV), the most malignant primary brain tumor, the rapid, radial growth phase that leads quickly to death is consistently preceded by the development of central necrosis. While genetic alterations of GBM are known in great detail, the biological properties that result from their acquisition and lead to this accelerated growth phase require deeper investigation. The tumor microenvironment (TME) changes dramatically following the onset of necrosis, from a sheet-like growth of infiltrating cells with relatively constant growth properties to a highly complex and evolving 3-D microsystem composed of diverse cell types and spatially segregated signaling networks. To better understand the dynamic temporal and spatial changes that promote progression, we propose to advance mouse models that closely parallel these events in human gliomas, since many mouse models of GBM lack necrosis. We developed a novel method to induce focal necrosis within high grade gliomas in vivo and will study TME restructuring and its impact on glioma growth in real time using multiphoton microscopy. As translational applications, we will demonstrate how hypoxia and necrosis promote the enrichment of glioma stem cells (GSCs) in their peri-necrotic niche and lead to the dramatic influx of tumor-associated macrophages (TAMs), which increase in number over 10-fold in the human disease. We propose both genetically characterized patient-derived GBM xenografts grown in mice with humanized immune cells, as well as an immunocompetent RCAS/tv-a model, and will determine how antagonizing these processes impact disease progression and outcomes. Our preliminary data and the literature indicate substantial differences between pre-necrotic and necrotic gliomas with regard to GSC and TAM enrichment and their impact on biological properties, but the mechanisms and evolution have not been studied in depth, in large part due to the absence of a credible animal model. Our model will capture glioma growth dynamics, GSC enrichment, and TAM influx, and facilitate the development of therapies that antagonize these mechanisms to improve outcomes.