Investigating and Targeting TAMs in the Glioma Microenvironment

研究和靶向胶质瘤微环境中的 TAM

• 批准号: 8840195
• 负责人: Johanna Joyce
• 金额: $ 39.58万
• 依托单位: SLOAN-KETTERING INST CAN RESEARCH
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-05-01 至 2019-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8840195
• 关键词: Address; Adult; Affect; Biological; Biological Assay; Blood Vessels; Brain; Cells; Clinic; Clinical; Coculture Techniques; Communication; Complement; Complex; Cytokine Signaling; Data; Development; Diagnosis; Disease; Employee Strikes; Exposure to; Future; Gene Expression Profile; Gene Expression Profiling; Genetically Engineered Mouse; Genomics; Glioblastoma; Glioma; Gliomagenesis; Goals; Grant; Granulocyte-Macrophage Colony-Stimulating Factor; Health; Homeostasis; Human; Hypoxia; Immune; Infection; Interferons; Investigation; Knowledge; MEKs; Macrophage Colony-Stimulating Factor; Macrophage Colony-Stimulating Factor Receptor; Malignant Neoplasms; Malignant neoplasm of brain; Mediating; Mediator of activation protein; Memorial Sloan-Kettering Cancer Center; Mesenchymal; Methods; Modeling; Molecular; Molecular Profiling; Mus; Mutation; Normal Cell; Normal tissue morphology; Outcome; Pathway interactions; Patients; Phenotype; Pilot Projects; Platelet-Derived Growth Factor; Primary Brain Neoplasms; Process; Proteomics; Radiosurgery; Receptor Inhibition; Recurrence; Resistance; Resistance development; Signal Pathway; Signal Transduction; Stromal Cells; Testing; Therapeutic; Translating; Tumor Cell Invasion; base; cancer cell; cancer type; cell type; chemotherapy; combat; design; enhancing factor; fighting; in vivo; inhibitor/antagonist; innovation; insight; macrophage; mouse model; neoplastic cell; nestin protein; novel; novel therapeutic intervention; outcome forecast; preclinical study; relating to nervous system; research study; response; targeted treatment; temozolomide; therapeutic development; therapeutic target; therapy resistant; tumor; tumor growth; tumor microenvironment; tumorigenesis; tumorigenic

DESCRIPTION (provided by applicant): High-grade gliomas, also known as glioblastoma multiforme (GBM), are the most common and aggressive adult primary brain tumors. GBM patients have a minimal response to current therapies, including surgery, radiation and temozolomide chemotherapy. Most patients die within 14 months following diagnosis, emphasizing the urgent need for new therapies to combat this disease. GBM can be grouped into several molecular subtypes, including proneural, neural, mesenchymal and classical, based on distinct gene expression signatures. Of these subtypes, proneural GBM is particularly aggressive in younger patients, and most therapeutic approaches aimed at directly targeting tumor cells in this subtype have failed. In contrast to highly mutable tumor cells, non-cancerous stromal cells that support tumorigenesis in the tumor microenvironment (TME) represent genetically stable therapeutic targets. This means therapies targeted against the TME are less likely to result in the development of acquired resistance as a result of genetic changes in the stromal cells. Tumor-associated macrophages (TAMs) are an important cell type in the TME that correlate with increased tumor grade and poor patient prognosis in many cancers, including gliomas, suggesting important cancer-promoting functions. To examine the contribution of TAMs to glioma progression, we have used a genetically engineered mouse model of proneural GBM. We found that TAMs progressively increase with higher tumor grade in the mouse model, which parallels the increase observed during human glioma development. To investigate the functional significance of TAM accumulation, we designed preclinical trials in the proneural GBM model to therapeutically target colony stimulating factor-1 receptor (CSF-1R), which macrophages depend upon for survival and differentiation. CSF-1R inhibition as a monotherapy dramatically increased survival in these mice, and regressed established tumors after just 7 days. Macrophages were depleted in the normal brain, as we had expected, but not in gliomas of treated mice. Instead, glioma-secreted factors facilitated TAM survival in the presence of CSF-1R inhibitors. Interestingly, gene expression analysis of these surviving TAMs revealed a significant decrease in alternatively activated/ M2 polarization macrophage markers, and consistently, functional analyses revealed anti-tumorigenic phenotypes. Thus, TAM depletion is not strictly necessary for effective macrophage-targeted therapy. Rather, we propose that the presence of macrophage survival factors in the glioma TME not only enables TAMs to survive exposure to a CSF-1R inhibitor, but to be 're-educated' through this process, resulting in a striking anti-tumor response. Our preliminary data identifies TAMs as a promising therapeutic target for proneural gliomas, and establishes strong translational potential of CSF-1R inhibition in GBM. In this proposal, we will expand on these results to elucidate the mechanisms by which TAMs mediate glioma cell phenotypes, and determine how CSF-1R inhibitors interfere with this reciprocal communication to delay and block glioma progression. Our objectives are to elucidate how TAMs are initially educated by glioma cells, and then re-educated by CSF-1R inhibition in the glioma microenvironment. Next, we will investigate which glioma cell signaling pathways are enhanced by TAMs, and determine the downstream effectors that are critical to CSF-1R inhibition efficacy in vivo. Finally, we will determine whether gliomas develop resistance to CSF-1R inhibition, and identify the underlying mechanisms. To address these goals, we will employ multiple different methods including mouse glioma models and an extensive panel of co-culture assays to investigate communication between glioma cells, TAMs, and other cells in the glioma TME. We will combine analyses of known signaling pathways with the identification of novel targets using proteomics and expression profiling approaches. In addition to dissecting the underlying biological mechanisms by which TAMs promote glioma progression, the proposed experiments will also result in the development of therapeutic strategies for their specific inhibition, which if successful could ultimately be tested in the clinic. Collectively, these studies have important implications for future clinical consideration of CSF-1R inhibitors, and for other therapies that target the TME in cancer.

描述(申请人提供)：高级别胶质瘤，也被称为多形性胶质母细胞瘤(GBM)，是最常见和最具侵袭性的成人原发脑肿瘤。GBM患者对目前的治疗方法反应很小，包括手术、放疗和替莫唑胺化疗。大多数患者在确诊后14个月内死亡，强调迫切需要新的治疗方法来对抗这种疾病。根据不同的基因表达特征，基底膜可分为几个分子亚型，包括原神经型、神经型、间叶型和经典型。在这些亚型中，神经性基底膜在年轻患者中尤其具有侵袭性，大多数直接针对该亚型肿瘤细胞的治疗方法都失败了。 与高度变异的肿瘤细胞不同，在肿瘤微环境(TME)中支持肿瘤发生的非癌症基质细胞代表着遗传稳定的治疗靶点。这意味着针对TME的治疗不太可能由于基质细胞的遗传变化而导致获得性耐药性的发展。肿瘤相关巨噬细胞(TAMs)是TME中的一种重要细胞类型，在包括胶质瘤在内的许多癌症中与肿瘤分级增加和患者预后不良相关，提示其具有重要的促癌作用。为了研究TAMs在胶质瘤进展中的作用，我们使用了一种遗传工程的小鼠神经基底膜模型。我们发现，在小鼠模型中，TAMs随着肿瘤分级的增加而逐渐增加，这与在人类胶质瘤发展过程中观察到的增加平行。 为了探讨蓄积的功能意义，我们设计了以巨噬细胞生存和分化所依赖的集落刺激因子-1受体为靶点的临床前实验。作为一种单一疗法，抑制CSF-1R显著提高了这些小鼠的存活率，并在7天后使已建立的肿瘤消退。正如我们预期的那样，巨噬细胞在正常大脑中被耗尽，但在接受治疗的小鼠的胶质瘤中却没有。相反，在脑脊液-1R抑制剂存在的情况下，胶质瘤分泌因子促进了的存活。有趣的是，这些存活的TAM的基因表达分析显示，交替激活的/M2极化巨噬细胞标志物显著减少，功能分析一致地揭示了抗肿瘤表型。因此，有效的巨噬细胞靶向治疗并不是严格意义上的耗竭。相反，我们认为在胶质瘤TME中巨噬细胞存活因子的存在不仅使TAMS能够在暴露于CSF-1R抑制剂的情况下存活，而且通过这一过程得到“再教育”，从而产生显著的抗肿瘤反应。 我们的初步数据表明TAMS是治疗神经前神经胶质瘤的一个有前途的靶点，并建立了在GBM中抑制CSF-1R的强大翻译潜力。在这项提案中，我们将在这些结果的基础上进一步阐明TAMS介导胶质瘤细胞表型的机制，并确定CSF-1R抑制剂如何干扰这种相互联系以延缓和阻止胶质瘤的进展。我们的目标是阐明TAM最初是如何被胶质瘤细胞教育的，然后是如何在胶质瘤微环境中通过抑制CSF-1R来再教育的。接下来，我们将研究TAMS增强了哪些胶质瘤细胞的信号通路，并确定了在体内对CSF-1R抑制效果至关重要的下游效应因子。最后，我们将确定胶质瘤是否对CSF-1R抑制产生抵抗，并确定其潜在的机制。 为了达到这些目标，我们将使用多种不同的方法，包括小鼠胶质瘤模型和一系列广泛的共培养试验，以研究胶质瘤细胞、TAMs和胶质瘤TME中其他细胞之间的通讯。我们将使用蛋白质组学和表达谱方法将已知信号通路的分析与新靶点的识别结合起来。除了剖析TAMs促进胶质瘤进展的潜在生物学机制外，拟议的实验还将导致开发针对其特定抑制的治疗策略，如果成功，最终可能会在临床上进行测试。总而言之，这些研究对未来临床考虑使用CSF-1R抑制剂以及针对TME治疗癌症的其他疗法具有重要意义。