神经胶质瘤的治疗策略

神经胶质瘤是来源于神经上皮的肿瘤,是颅内最常见的恶性肿瘤,约占中枢神经系统肿瘤的40%~50%。主要分为星型细胞瘤、胶质母细胞瘤、少突胶质细胞瘤、髓母细胞瘤、室管膜瘤等。如何提高胶质瘤的治疗效果,提高病人的生命质量,仍是神经外科医生面临的巨大难题。     

神经胶质瘤的治疗策略

神经胶质瘤是来源于神经上皮的肿瘤,是颅内最常见的恶性肿瘤,约占中枢神经系统肿瘤的40%~50%。主要分为星型细胞瘤、胶质母细胞瘤、少突胶质细胞瘤、髓母细胞瘤、室管膜瘤等。如何提高胶质瘤的治疗效果,提高病人的生命质量,仍是神经外科医生面临的巨大难题。     

脑胶质瘤治疗相关时空演化机制及其在精准治疗中的应用

胶质母细胞瘤是成人中最恶性的颅内肿瘤,但其治疗方式在过去数十年未有突破. 随着近年精准医学和下一代测序技术的发展,使研究胶质母细胞瘤背后多维基因组学的复杂机制成为可能. 其中继发胶质母细胞瘤及与其配对的原发肿瘤是十分珍贵的数据,可用以分析低级别胶质瘤在时间和空间轴上的演化以及治疗对肿瘤的影响. 本综述阐述胶质母细胞瘤的复杂性,包括各种驱动突变、空间上的异形性和不同的演化方式;此外,会讨论如何将这些基因学上的发现应用在肿瘤预后的预测以及精准治疗上.     

脑胶质瘤治疗相关时空演化机制及其在精准治疗中的应用（英文）

胶质母细胞瘤是成人中最恶性的颅内肿瘤,但其治疗方式在过去数十年未有突破.随着近年精准医学和下一代测序技术的发展,使研究胶质母细胞瘤背后多维基因组学的复杂机制成为可能.其中继发胶质母细胞瘤及与其配对的原发肿瘤是十分珍贵的数据,可用以分析低级别胶质瘤在时间和空间轴上的演化以及治疗对肿瘤的影响.本综述阐述胶质母细胞瘤的复杂性,包括各种驱动突变、空间上的异形性和不同的演化方式;此外,会讨论如何将这些基因学上的发现应用在肿瘤预后的预测以及精准治疗上.     

脑胶质瘤动物模型的研究及应用进展

脑胶质瘤约占中枢神经肿瘤的一半,临床治疗效果差。尤其是胶质母细胞瘤,其恶性程度极高,预后性差,是威胁人类健康的主要恶性肿瘤之一,因此,选择一种有效的动物模型是研究脑胶质瘤发病机制及其治疗方法的关键。随着分子生物学、遗传学的发展,尤其是转基因小鼠,以及其他越来越多模式生物的出现,目前已建立了多种脑胶质瘤动物模型。该文将对目前所建立的各种脑胶质瘤动物模型予以综述。     

人源化YKL-40中和抗体（Rosazumab） 体外阻断血管再生

摘要 目的：血管再生是实体肿瘤的生长和恶性转移的一个必须病理过程,阻断这一过程能够有效阻止恶性肿瘤的发生发展。YKL-40是血管再生因子,能刺激肿瘤的血管再生。本文探讨了一个原创性人源化抗YKL-40单克隆抗体（Rosazumab, 命名为洛沙单抗）阻断YKL-40血管生成的体外功能。方法：Western Blot检测洛沙单抗对分泌和重组YKL-40蛋白的特异性结合;Western Blot及考马斯亮蓝染色检测该抗体的抗体特异性和纯度;Live/Dead染色试验检测抗体的细胞毒性。以人微血管内皮细胞（Human microvascular endothelial cells, HMVECs）为研究对象,引入重组YKL-40蛋白或脑胶质瘤细胞（Glioblastoma serum-differentiated cells, GSDCs）的条件培养基进行培养。Transwell试验检测该抗体对HMVECs迁移力的影响,并用Matrigel试验检测对微管形成的作用。结果：洛沙单抗可特异性结合YKL-40,考马斯亮蓝染色进一步证明其纯度及特异性。体外血管再生试验包括细胞迁移力和微管形成证明该抗体可以有效中和重组YKL-40蛋白及肿瘤细胞条件培养基中的YKL-40,抑制HMVECs的迁移和血管形成。结论：洛沙单抗是首创的人源化中和YKL-40的抗体,其特异性高,细胞毒性低,能显著抑制YKL-40血管再生功能,为下一步体内试验奠定基础。本研究可为YKL-40诱导的肿瘤血管生成及恶性肿瘤转移提供一种新的治疗手段。     

替莫唑胺治疗胶质母细胞瘤的耐药性产生机制研究进展

胶质母细胞瘤作为胶质瘤中恶性程度最高的原发性脑部肿瘤,具有治愈率低、复发率高、呈浸润性生长等特点,在不使用化疗药物的情况下,患者中位生存期仅为12.1个月。胶质母细胞瘤患者的标准治疗方法以手术切除为主,放化疗为辅,其中替莫唑胺（temozolomide,TMZ）作为一种新型的口服烷化剂,是目前用于胶质瘤化学治疗的一线药物。但经过替莫唑胺治疗后,患者中位生存期仅提高了2个月,主要原因为胶质母细胞瘤可对TMZ产生耐药性。胶质母细胞瘤对TMZ产生的耐药机制主要为DNA修复机制,其包括了O⁶?甲基鸟嘌呤DNA甲基转移酶（O⁶?methyl guanine DNA methyltransferase,MGMT）对药物作用位点进行的直接修复、错配修复（mismatch repair,MMR）及碱基切除修复（base excision repair,BER）,这些修复机制可修复TMZ引起的DNA损伤,从而降低肿瘤细胞对TMZ敏感性。通过对近年来胶质母细胞瘤的TMZ耐药机制的研究进展进行介绍,旨在为发展新的治疗手段提供理论基础。     

寨卡病毒可作为溶瘤病毒特异杀伤胶质瘤干细胞

正胶质母细胞瘤(glioblastoma)是一种恶性程度最高的原发性脑肿瘤.由于肿瘤生长快、侵袭性强,常规手术、放疗、化疗等治疗后复发率极高,预后差,绝大多数患者生存期中位数低于两年[1].胶质母细胞瘤的成因复杂,最新研究显示胶质瘤干细胞(glioblastoma stem cells, GSCs)可能在其中发挥了关键作用.胶质瘤干细胞是一群具备无限增殖、自我更新和多向分化等类干细胞潜能的细胞,不仅参与促进肿瘤血管生成,而且能够抵抗放化疗的杀瘤作用[2].以胶质瘤干细胞为     

m~6A甲基化修饰对胶质母细胞瘤恶性进展影响的研究现状

胶质母细胞瘤是成人最常见、最具侵袭性的原发性脑肿瘤,该肿瘤进展快速,预后差。近年来,分子靶向治疗以其特异性和有效性成为胶质母细胞瘤治疗的研究热点,但对胶质母细胞瘤的分子异质性和发病机制尚不清楚。6-甲基腺嘌呤(m~6A)作为真核生物信使RNA(mRNA)中最丰富的内部修饰,参与了人类多种复杂疾病的发生发展过程,尤其在癌症的发生发展中具有重要作用。有研究结果表明m~6A甲基化调控胶质母细胞瘤干细胞的增殖并且当m~6A甲基化减少时可促进胶质母细胞瘤干细胞的恶性进展,但也有研究表明m~6A甲基化水平降低时可抑制胶质母细胞瘤干细胞的恶性进展。因此就目前研究现状看,m~6A的甲基化和去甲基化可能会影响胶质母细胞瘤恶性进展,也是胶质母细胞瘤目前仍存在争议且相关研究较少的一个方向。发现RNA中m~6A的关键功能可能会为胶质母细胞瘤的治疗提供新的思路。     

研究报告: 星形胶质细胞瘤分泌一氧化氮促进炎性水肿带相关肿瘤微环境的研究

目的 检测在星形胶质细胞瘤中一氧化氮（nitric oxide，NO）的表达及促进炎性水肿带相关肿瘤微环境的作用。方法 收集27例星形胶质细胞瘤患者的临床资料和肿瘤标本（WHO II级10例、II-III级7例、IV级10例），磁共振成像确认水肿带及手术取材部位；格里斯试剂比色法检测亚硝酸盐含量；质谱分析不同级别星形胶质细胞瘤（不同级别各5例）水肿带炎性分子含量；通过ClusterProfiler包以及Proteomaps和Metascape网页工具进行富集分析预测肿瘤分泌的NO与微环境中互作的蛋白质。结果 星形胶质细胞瘤组织及水肿带中存在NO，胶质瘤组织中的NO高于水肿带中的NO。在WHO II-III级和WHO IV级胶质瘤的水肿带中，有大量超氧化物歧化酶、细胞色素C氧化酶、热休克蛋白、CD44抗原，白介素-8、白介素-24、凝溶胶蛋白、应激诱导磷酸蛋白1、丝裂原活化蛋白激酶、硫氧还蛋白过氧化物酶、S100蛋白等炎症相关蛋白质的表达。信号通路分析提示，与II-III级别星形胶质细胞瘤相比，Ⅳ级胶质母细胞瘤水肿带中的基因更多地参与无氧代谢，如糖酵解。更重要的是，这些目标基因显著参与多种氧化还原反应，如氧化还原酶活性和过氧化物酶活性。其中，诱导性一氧化氮合酶（inducible NOS，iNOS）、NO、过氧亚硝酸阴离子（ONOO^-）、铜/锌超氧化物歧化酶（Cu/Zn superoxide dismutase，SOD-1）在氧化还原反应中发挥重要作用。结论 星形胶质细胞瘤周围水肿带的形成是炎症反应的结果，胶质瘤细胞通过分泌NO调控SOD-1等炎性分子促进侵袭性炎性肿瘤微环境的形成。     

Role of YKL-40 in the angiogenesis, radioresistance, and progression of glioblastoma

Glioblastoma is one of the most fatal cancers, characterized by a strong vascularized phenotype. YKL-40, a secreted glycoprotein, is overexpressed in patients with glioblastomas and has potential as a novel tumor biomarker. The molecular mechanisms of YKL-40 in glioblastoma development, however, are poorly understood. Here, we aimed to elucidate the role YKL-40 plays in the regulation of VEGF expression, tumor angiogenesis, and radioresistance. YKL-40 up-regulated VEGF expression in glioblastoma cell line U87, and both YKL-40 and VEGF synergistically promote endothelial cell angiogenesis. Interestingly, long term inhibition of VEGF up-regulated YKL-40. YKL-40 induced coordination of membrane receptor syndecan-1 and integrin αvβ5, and triggered a signaling cascade through FAK(397) to ERK-1 and ERK-2, leading to elevated VEGF and enhanced angiogenesis. In addition, γ-irradiation of U87 cells increased YKL-40 expression that protects cell death through AKT activation and also enhances endothelial cell angiogenesis. Blockade of YKL-40 activity or expression decreased tumor growth, angiogenesis, and metastasis in xenografted animals. Immunohistochemical analysis of human glioblastomas revealed a correlation between YKL-40, VEGF, and patient survival. These findings have shed light on the mechanisms by which YKL-40 promotes tumor angiogenesis and malignancy, and thus provide a therapeutic target for tumor treatment.     

Chitinase 3-like protein 2 (CHI3L2, YKL-39) activates phosphorylation of extracellular signal-regulated kinases ERK1/ERK2 in human embryonic kidney (HEK293) and human glioblastoma (U87 MG) cells

Human cartilage chitinase 3-like protein 2 (CHI3L2, YKL-39) is secreted by articular chondrocytes, also synoviocytes, lung, and heart. Increased levels of YKL-39 have been demonstrated in synovial fluids of patients with rheumatoid or osteoarthritis as well as in some other pathologies and in malignant tumors, particularly in glioblastomas. It belongs to glycosyl hydrolase family 18 and the most closely related to human cartilage glycoprotein 39 (HC gp-39 or chitinase 3-like protein 1, CHI3L1 or YKL-40), which as it was shown previously, promotes the growth of human synovial cells as well as skin and fetal lung fibroblasts. Dose-dependent growth stimulation was observed when the fibroblastic cell line was exposed to YKL-40 in a concentration range from 0.1 to 2 nM, which is similar to the effective dose of the well characterized mitogen, insulinlike growth factor I. The use of selective inhibitors of the mitogen-activated protein kinase (MAP kinase) signaling pathway indicates that both, YKL-40 and IGF-I are involved in phosphorylation of extracellular signal-regulated kinases 1 and 2 (ERK1/ERK2). Thus YKL-40 initiates a signaling cascade which leads to increased cell proliferation, suggesting that this protein could play some role in the inhibition of apoptosis. We report here that YKL-39, which as YKL-40 has significantly increased expression in glioblastomas, also activates signal-regulated kinases ERK1/ERK2 in human embryonic kidney (HEK293) and human glioblastoma (U87 MG) cells.     

Prognostic Value of YKL-40 in Patients with Glioblastoma: a Systematic Review and Meta-analysis

YKL-40 is the most highly expressed gene in glioblastoma compared with normal brain tissues. Previous studies assessing the association between YKL-40 and survival in glioblastoma patients reported varying magnitude of estimates. The objective of this meta-analysis was to determine the prognostic value of YKL-40 in glioblastoma patients. PubMed and Embase databases were searched for studies relating to YKL-40 and prognosis of glioblastoma patients. Studies reporting estimates for overall survival by YKL-40 expression in glioblastoma patients were considered eligible. A meta-analysis of included studies was performed using fixed- or random-effect model to calculate the pooled hazard ratio (HR) and 95 % confidence interval (95%CI). Eight studies were ultimately considered eligible and included into the meta-analysis. Those eight studies included 1241 glioblastoma patients. Meta-analysis of those studies showed that high YKL-40 expression was associated with worse overall survival in glioblastoma patients (HR?=?1.46, 95%CI 1.33–1.61, P?<?0.001). Meta-analysis of studies with adjusted estimates and high quality showed that high YKL-40 expression was independently associated with worse overall survival in glioblastoma patients (HR?=?1.50, 95%CI 1.35–1.66, P?<?0.001). Both subgroup analysis and sensitivity analysis validated the obvious association between high YKL-40 expression and worse overall survival in glioblastoma patients. High YKL-40 expression is independently and markedly associated with worse overall survival in glioblastoma patients. YKL-40 is a good predictive biomarker of prognosis in glioblastoma patients.     

Selective repression of YKL-40 by NF-kappaB in glioma cell lines involves recruitment of histone deacetylase-1 and -2

Here we show that in contrast to other cancer types, tumor necrosis factor (TNF)-alpha suppresses YKL-40 expression in glioma cell lines in a nuclear factor kappaB (NF-kappaB) dependent manner. Even though TNF-alpha causes recruitment of p65 and p50 subunits of NF-kappaB to the YKL-40 promoter in all cell types, recruitment of histone deacetylases (HDAC)-1 and -2, and a consequent deacetylation of histone H3 at the YKL-40 promoter occurs only in glioma cells. Importantly, using chromatin immunoprecipitation assays in frozen glioblastoma multiforme tissues, we show that YKL-40 levels decrease consistent with HDAC1 recruitment despite high levels of nuclear p-p65. This study presents a paradigm for NF-kappaB regulation of one of its targets in a strict cell type specific manner.     

Preferential migration of regulatory T cells mediated by gliomasecreted chemokines can be blocked with chemotherapy

Despite the immunogenicity of glioblastoma multiforme (GBM), immune-mediated eradication of these tumors remains deficient. Regulatory T cells (Tregs) in the blood and within the tumor microenvironment of GBM patients are known to contribute to their dismal immune responses. Here, we determined which chemokine secreted by gliomas can preferentially induce Treg recruitment and migration. In the malignant human glioma cell lines D-54, U-87, U-251, and LN-229, the chemokines CCL22 and CCL2 were detected by intracellular cytokine analysis. Furthermore, tumor cells from eight patients with GBM had a similar chemokine expression profile. However, only CCL2 was detected by enzyme-linked immunosorbent assay, indicating that CCL2 may be the principal chemokine for Treg migration in GBM patients. Interestingly, the Tregs from GBM patients had significantly higher expression levels of the CCL2 receptor CCR4 than did Tregs from healthy controls. Glioma supernatants and the recombinant human chemokines CCL2 and CCL22 induced Treg migration and were blocked by antibodies to the chemokine receptors. Production of CCL2 by glioma cells could also be mitigated by the chemotherapeutic agents temozolomide and carmustine [3-bis (2-chloroethyl)-1-nitrosourea]. Our results indicate that gliomas augment immunosuppression by selective chemokine-mediated recruitment of Tregs into the tumor microenvironment and that modulating this interaction with chemotherapy could facilitate the development of novel immunotherapeutics to malignant gliomas. Justin T. Jordan and Wei Sun are contributed equally to this work. An erratum to this article can be found at     

PIMREG expression level predicts glioblastoma patient survival and affects temozolomide resistance and DNA damage response

PIMREG expression strongly correlates with cellular proliferation in both malignant and normal cells. Throughout embryo development, PIMREG expression is prominent in the central nervous system. Recent studies have described elevated PIMREG expression in different types of tumors, which correlates with patient survival and tumor aggressiveness. Given the emerging significance of PIMREG in carcinogenesis and its putative role in the context of the nervous system, we investigated the expression and function of PIMREG in gliomas, the most common primary brain tumors. We performed an extensive analysis of PIMREG expression in tumors samples from glioma patients. We then assessed the effects of PIMREG silencing and overexpression on the sensitivity of glioblastoma cell lines treated with genotoxic agents commonly used for treating patients and assessed for treatment response, proliferation and migration. Our analysis shows that glioblastoma exhibits the highest levels of PIMREG expression among all cancers analyzed and that elevated PIMREG expression is a biomarker for glioma progression and patient outcome. Moreover, PIMREG is induced by genotoxic agents, and its silencing renders glioblastoma cells sensitive to temozolomide treatment and affects ATR- and ATM-dependent signaling. Our data demonstrate that PIMREG is involved in DNA damage response and temozolomide resistance of glioblastoma cells and further supports a role for PIMREG in tumorigenesis.     

The pro-migratory and pro-invasive role of the procoagulant tissue factor in malignant gliomas

During the infiltration process, glioma cells are known to migrate along preexisting anatomical structures such as blood vessels, axonal fiber tracts and the subependymal space, thereby widely invading surrounding CNS tissue. This phenomenon represents a major obstacle for the clinical treatment of these tumours. Several extracellular key factors and intracellular signaling pathways have been previously linked to the highly aggressive, invasive phenotype observed in malignant gliomas. The glioblastoma (GBM) which is the most malignant form of these tumors, is histologically characterized by areas of tumor necroses and pseudopalisading cells, the latter likely representing tumor cells actively migrating away from the hypoxic-ischemic core of the tumor. It is believed that intravascular thromboses play a major role in the emergence of hypoxia and intratumoral necroses in GBMs. One of the most highly upregulated prothrombotic factor in malignant gliomas is tissue factor (TF), a 47 kDa type I transmembrane protein belonging to the cytokine receptor superfamily. In a recent study, we provided evidence that TF/FVIIa signaling via the protease-activated receptor 2 (PAR-2) promotes cell growth, migration and invasion of glioma cells. In this point of view article we outline the key molecular players involved in migration and invasion of gliomas, highlight the potential role of TF for the pro-migratory and pro-invasive phenotype of these tumors and discuss the underlying mechanisms on the cellular level and in the tumor microenvironment.     

The pro-migratory and pro-invasive role of the procoagulant tissue factor in malignant gliomas

During the infiltration process, glioma cells are known to migrate along preexisting anatomical structures such as blood vessels, axonal fiber tracts and the subependymal space, thereby widely invading surrounding CNS tissue. This phenomenon represents a major obstacle for the clinical treatment of these tumors. Several extracellular key factors and intracellular signaling pathways have been previously linked to the highly aggressive, invasive phenotype observed in malignant gliomas. The glioblastoma (GBM), which is the most malignant form of these tumors, is histologically characterized by areas of tumor necroses and pseudopalisading cells, the latter likely representing tumor cells actively migrating away from the hypoxic- ischemic core of the tumor. It is believed that intravascular thromboses play a major role in the emergence of hypoxia and intratumoral necroses in GBMs. One of the most highly upregulated prothrombotic factor in malignant gliomas is tissue factor (TF), a 47 kDa type I transmembrane protein belonging to the cytokine receptor superfamily. In a recent study, we provided evidence that TF/FVIIa signaling via the protease-activated receptor 2 (PAR-2) promotes cell growth, migration and invasion of glioma cells. In this Commentary & View, we outline the key molecular players involved in migration and invasion of gliomas, highlight the potential role of TF for the pro-migratory and pro-invasive phenotype of these tumors and discuss the underlying mechanisms on the cellular level and in the tumor microenvironment.Key words: brain tumor, blood coagulation, hypoxia, MAP kinase, cancer stem cells, tumor invasion     

A bidirectional crosstalk between glioblastoma and brain endothelial cells potentiates the angiogenic and proliferative signaling of sphingosine-1-phosphate in the glioblastoma microenvironment

Glioblastoma is one of the most malignant, angiogenic, and incurable tumors in humans. The aberrant communication between glioblastoma cells and tumor microenvironment represents one of the major factors regulating glioblastoma malignancy and angiogenic properties. Emerging evidence implicates sphingosine-1-phosphate signaling in the pathobiology of glioblastoma and angiogenesis, but its role in glioblastoma-endothelial crosstalk remains largely unknown. In this study, we sought to determine whether the crosstalk between glioblastoma cells and brain endothelial cells regulates sphingosine-1-phosphate signaling in the tumor microenvironment. Using human glioblastoma and brain endothelial cell lines, as well as primary brain endothelial cells derived from human glioblastoma, we report that glioblastoma-co-culture promotes the expression, activity, and plasma membrane enrichment of sphingosine kinase 2 in brain endothelial cells, leading to increased cellular level of sphingosine-1-phosphate, and significant potentiation of its secretion. In turn, extracellular sphingosine-1-phosphate stimulates glioblastoma cell proliferation, and brain endothelial cells migration and angiogenesis. We also show that, after co-culture, glioblastoma cells exhibit enhanced expression of S1P₁ and S1P₃, the sphingosine-1-phosphate receptors that are of paramount importance for cell growth and invasivity. Collectively, our results envision glioblastoma-endothelial crosstalk as a multi-compartmental strategy to enforce pro-tumoral sphingosine-1-phosphate signaling in the glioblastoma microenvironment.