The role and mechanism of necrosis in glioblastoma

项目摘要 胶质瘤是主要的原发脑肿瘤，其中胶质母细胞瘤是最常见和侵袭性最强的肿瘤。 表格。这些肿瘤的传统治疗效果不佳，需要基于以下因素的靶向治疗 确定了驱动肿瘤发展的机制。分子病理学将基底膜分为亚型， 其中间充质(MES)组恶性程度最高。目前仍不清楚GBM是如何 实现了差异化。最近基于解剖学的转录组研究发现，肿瘤细胞与 与坏死区有较高表达的MES标志性基因，提示坏死性肿瘤 微环境可能有助于MES的分化，可作为治疗的靶点。目标是 本项目的目的是从力学和功能上研究GBM的坏死，识别GBM MES的脆弱性 治疗学的进展。我们为拟议的研究确立了以下前提。首先，我们有 建立了新的病理相关的GBM小鼠模型，显示出MES分化和广泛的坏死。 其次，我们发现铁性下垂是基底膜坏死的一种新机制。第三，在两个患者的GBM样本中 和小鼠模型，我们发现坏死的肿瘤区域有中性粒细胞的渗透。我们的研究表明 这些肿瘤相关的中性粒细胞(TANs)是诱导肿瘤细胞铁下垂的必要条件和充分条件。 此外，我们还发现铁性下垂和TANS与缺氧的肿瘤微环境有关。我们 假设基底膜坏死是通过中性粒细胞触发的铁下垂发生的，并且这个过程是精心策划的 受低氧肿瘤微环境的影响。我们进一步假设铁性下垂可以促进肿瘤的发生 进展，并成为治疗目的的目标。我们提出以下三个具体目标：1) 确定TANS诱导肿瘤细胞铁下垂的机制；2)确定缺氧性肿瘤的作用 肿瘤细胞铁性下垂的微环境；3)阐明铁性下垂在GBM进展和预后中的作用 评价铁性下垂阻滞剂的疗效。我们将使用一组已建立的人类GBM细胞系， 新分离的人肾小球系膜细胞和小鼠肾小球系膜细胞模型。预测，基底膜坏死是一个诊断标志 肿瘤侵袭性，并对治疗产生有害影响。细胞死亡的本质和机制 与此坏死相关的疾病仍不清楚。此外，肿瘤坏死阻断是否能受益 治疗方法仍然是未知的。通过建立真实再现坏死程度的基底膜模型 在基底膜患者中观察到的，并确定铁性下垂是肿瘤坏死的潜在机制 该提案将揭示GBM MES进展的漏洞，这可能是GBM的一条新途径 治疗学。

Project Summary Gliomas are major primary brain tumors, of which glioblastomas (GBM) are the most common and aggressive forms. The poor outcome of traditional treatment for these tumors demands targeted therapies based on identified mechanisms that drive tumor development. Molecular pathology has classified GBM into subtypes, among which the mesenchymal (MES) group is the most malignant. It is still unclear how GBM MES differentiation is achieved. Recent anatomically based transcriptome studies found that tumor cells associated with the necrotic region have higher expression of the MES signature genes, suggesting that the necrotic tumor microenvironment may contribute to MES differentiation and could be exploited as a therapeutic target. The goal of this project is to mechanistically and functionally study GBM necrosis, and identify vulnerabilities of GBM MES progression for therapeutics. We have established the follow premise for the proposed studies. First, we have developed novel pathologically relevant GBM mouse models showing MES differentiation and extensive necrosis. Second, we identified ferroptosis as a novel mechanism for GBM necrosis. Third, in both patient GBM samples and mouse models, we found that the necrotic tumor areas are infiltrated by neutrophils. Our studies suggested that these tumor-associated neutrophils (TANs) are necessary and sufficient to induce tumor cell ferroptosis. Furthermore, we found that ferroptosis and TANs are associated with the hypoxic tumor microenvironment. We hypothesize that GBM necrosis occurs through neutrophil-triggered ferroptosis, and this process is orchestrated by the hypoxic tumor microenvironment. We further hypothesize that ferroptosis could promote tumor progression and be targeted for therapeutic purposes. We propose the following three specific aims: 1) to determine the mechanism of tumor cell ferroptosis induced by TANs; 2) to determine the role of hypoxic tumor microenvironment in tumor cell ferroptosis; 3) to demonstrate the role of ferroptosis in GBM progression and evaluate therapeutic effects of ferroptosis blockade. We will employ a panel of established human GBM cell lines, newly isolated human GBM cells, and mouse GBM models. GBM necrosis is a diagnostic hallmark, predicts tumor aggressiveness, and has deleterious effects on treatments. The nature and mechanism of cell death associated with this necrosis remain obscure. In addition, whether tumor necrosis blockade could benefit therapies is still unknown. By establishing the GBM models faithfully recapitulating the extent of necrosis observed in GBM patients and identification of ferroptosis as the underlying mechanism of tumor necrosis, this proposal will reveal vulnerabilities of GBM MES progression, which could be a novel avenue for GBM therapeutics.