The role of Tumor associated macrophages in glioblastoma

项目摘要(摘要) 胶质母细胞瘤(GBM)是最常见、最具侵袭性的原发脑肿瘤。肿瘤的浸润性 细胞使手术切除不完整。此外，尽管受到辐射和治疗，复发是不可避免的。 替莫唑胺治疗和患者在确诊后15个月内死亡。GBM分为几个部分 基于不同基因表达谱的分子亚型，包括原神经(PN)、间充质(MES)、 古典(CL)。目前的抗肿瘤疗法未能在 基底膜是肿瘤微环境的适应性本质。最丰富的非肿瘤细胞群 在基底膜微环境中是肿瘤相关巨噬细胞(TAMs)。在GBM亚型中，MES 表达最高水平的相关基因。我们对数字的分析表明，MES GBM 与其他亚型相比，TAM的数量也是最多的。当我们把高和低联系起来时 相关基因的表达水平与患者生存期呈亚型特异性，仅PNGBM 患者表现出高表达：短生存期和低表达：长生存期的相关性。PN GBM是 也是已知对抗肿瘤细胞特异性靶向治疗最具抵抗力的药物。检视--GBM 细胞相互作用，我们使用了基因工程免疫活性小鼠模型的PDGFB-和核因子-1丢失- 驱动基底膜，并显示肿瘤细胞诱导TAM产生关键的促炎细胞因子IL-1β。 TAMs释放IL-1β，与肿瘤细胞上的受体IL-1R1结合，导致IL-1β活化 PDGFB驱动的GBM细胞中的信号转导，导致i)茎和生长增加，ii)增加 单核细胞趋化蛋白(MCP)网络(CCL2、CCL7、CCL8、CCL12)在PDGFB中的表达 驱动的GBM细胞。我们的数据显示，微环境中IL-1β的丢失导致了显著的 与野生型小鼠相比，体内PDGFB驱动的GBM的形成和生长减少。根据我们的数据， 我们假设与基底膜细胞的相互作用是细胞类型和亚型特异的，并且它们具有 PN和MES GBM亚型的不同功能。在此应用程序中，我们将确定详细的 PN和MES GBM细胞募集和改变巨噬细胞功能以产生 专门的TAMS(目标1)。为了确定IL-1MCP信令的机制，β网络及其 利用基因工程小鼠模型研究PDGFB和NF1基因缺失驱动的GBM下游靶点 和体内人GSC来源的肿瘤。确定TAM和IL-1β支持的机制 创造和维持血管周围的壁龛，提供适当的微环境 对于胶质瘤干细胞--胶质瘤的治疗耐药群体(目标3)。拟议的研究将 对与有关的基本细胞和分子生物学过程提供了新的机械见解- 肿瘤细胞在体内的相互作用，并将有助于识别新的潜在治疗靶点 胶质母细胞瘤。

Project Summary (Abstract) Glioblastoma (GBM) is the most common and aggressive primary brain tumor. The infiltrative nature of tumor cells makes surgical resection incomplete. Furthermore, recurrence is inevitable despite radiation and temozolomide treatment and patients die within 15 months following diagnosis. GBM are divided into several molecular subtypes based on distinct gene expression profiles, including proneural (PN), mesenchymal (MES), classical (CL). One important reason that current anti-neoplastic therapies fail to provide a durable response in GBM is the adaptive nature of the tumor microenvironment. The most abundant non-neoplastic cell population in the GBM microenvironment is tumor-associated macrophages (TAMs). Of the GBM subtypes, MES expresses the highest levels of TAM-associated genes. Our analysis of TAM numbers revealed that MES GBM also has the highest number of TAMs compared to the other subtypes. When we correlated the high and low expression levels of TAM-associated genes with patient survival in a subtype-specific manner, only PN GBM patients showed a correlation of high expression: short survival and low expression: long survival. PN GBM is also known to be the most resistant to anti-neoplastic cell-specific targeted therapies. To examine TAM-GBM cell interactions, we used genetically engineered immunocompetent mouse models of PDGFB- and NF-1 loss- driven GBM and showed that tumor cells induce TAMs to produce the key pro-inflammatory cytokine IL-1β. TAMs release IL-1β, which binds to the receptor IL-1R1 on tumor cells and leads to activation of IL-1β signaling in PDGFB-driven GBM cells, which leads to i) increased stemness and growth, and ii) increased expression of the monocyte chemoattractant protein (MCP) network (CCL2, CCL7, CCL8, CCL12) in PDGFB- driven GBM cells. Our data showed that loss of IL-1β from the microenvironment resulted in a significant decrease in PDGFB-driven GBM formation and growth compared to wild-type mice in vivo. Based on our data, we hypothesize that TAM interaction with GBM cells is cell type- and subtype-specific and that they have different functions in PN and MES GBM subtypes. In this application, we will determine the detailed mechanism by which PN and MES GBM cells recruit and alter the function of macrophages to create specialized TAMs (Aim 1). To determine the mechanism of IL-1β signaling, the MCP network, and their downstream targets in PDGFB- and NF1 loss-driven GBM using genetically engineered mouse models and human GSC-derived tumors in vivo. Determine the mechanism by which TAMs and IL-1β support the creation and maintenance of the perivascular niche, which provides the proper microenvironment for glioma stem cells – the treatment-resistant population of glioma (Aim 3). The proposed studies will provide new mechanistic insights into fundamental cellular and molecular biological processes related to TAM– tumor cell interaction in vivo, and will allow for identification of novel potential therapeutic targets to glioblastoma.