胶质瘤中端粒酶逆转录酶启动子区突变分析及其预后意义

目的:探讨端粒酶逆转录酶(TERT)启动子区突变与胶质瘤患者临床病理指标的关系及其对预后的影响。方法:应用Sanger测序技术检测78例脑胶质瘤组织中TERT启动子区C228T和C250T位点的突变情况,分析TERT启动子区突变与临床病理指标的关系及其对预后的影响。结果:TERT启动子区突变在脑胶质瘤中的发生率为32.1%,在低级别(Ⅰ~Ⅱ)和高级别(Ⅲ~Ⅳ)胶质瘤中突变分别占28.0%和34.0%。其中少突星形细胞瘤中突变占57.1%,胶质母细胞瘤中突变占44.4%,低级别星形细胞瘤和少突胶质细胞瘤中突变分别占28.6%和23.1%。TERT启动子区突变与胶质瘤患者术后生存时间显著相关,突变型术后生存时间显著短于野生型(P=0.001)。按低级别和高级别分组独立分析后发现,TERT启动子区突变在低级别组和高级别组中均与不良预后相关(P值分别为0.019和0.018)。Cox回归分析表明,TERT启动子区突变和术后放化疗是独立的预后影响因素(P=0.002,HR=3.486,95%CI: 1.591 ~7.637;P=0.004,HR=0.331,95%CI:0.156～0.699)。结论:TERT启动子区突变频繁发生于脑胶质瘤中,突变型胶质瘤患者预后不良。     

低级别胶质瘤的分子遗传学：基因组改变指导诊断和治疗第十一届Frye-Halloran脑肿瘤研讨会报告（摘译）

2012年10月4日，胶质瘤研究相关领域的专家召开了一个小型专题会议，通过温习目前对于低级别胶质瘤的分子基因机制的认识．为进一步研究包括新药物的研发明确方向。会议主要有3个部分内容：IDH1突变的神经病理学、少突胶质细胞瘤和星形细胞瘤中的CIC、ATRX和FUBP1突变以及IDH1突变在治疗中的作用。会议由来自世界各地的顶级专家对包括低级别胶质瘤研究、突变的IDH1生物学及其在低级别胶质瘤研究和治疗中的应用前景作了10个议题的报告。会议结论：最近在低级别胶质瘤中发现的反复出现的基因突变增加了对于与低级别胶质瘤相关的生物学活性分子机制的理解．理解这些基因改变在脑肿瘤发生发展中的作用不但有助于患者个体化治疗方案的制订．更有助于发展新的治疗方法．将这种目前致命性的恶性肿瘤转变为慢性甚至是可以治愈的疾病。本文综合本次会议报告内容．重点介绍目前对低级别胶质瘤发展中潜在的分子基因机制的理解．以及这些机制作为靶点在诊断、治疗和复发中的运用。     

高分级胶质瘤的放化综合治疗

胶质瘤是起源于神经胶质细胞的肿瘤，主要包括星形细胞肿瘤、少突胶质细胞肿瘤和混合性胶质细胞肿瘤。星形细胞瘤是胶质瘤中最常见的类型，其中的间变性星形细胞瘤又称恶性星形细胞瘤，属WHOⅢ级。临床常将恶性星形细胞瘤和胶质母细胞瘤统称为恶性胶质瘤，而将Ⅲ级胶质瘤（如间变性星形细胞瘤，间变性少突胶质细胞瘤）、胶质母细胞瘤、胶质肉瘤等统称为高分级胶质瘤。     

少突胶质细胞瘤中染色体1p/19q联合缺失与MGMT基因启动子甲基化的相关性

目的 研究少突胶质细胞瘤染色体1p/19q联合缺失与MGMT基因启动子甲基化的相关性。方法 选取少突胶质细胞瘤35例、间变型少突胶质细胞瘤32例标本作为实验组,星形细胞瘤20例及瘤旁正常脑组织标本20例作为对照组,荧光原位杂交方法检测染色体1p/19q联合缺失情况,巢式甲基化特异性PCR技术检测MGMT基因启动子甲基化情况。结果 少突胶质细胞瘤和间变型少突胶质细胞瘤1p/19q联合缺失率分别为85.71%、75.00%,均显著高于星形细胞瘤及正常脑组织（P<0.05）;少突胶质细胞瘤、间变型少突胶质细胞瘤、星形细胞瘤的MGMT基因启动子甲基化率均显著高于正常脑组织（P<0.05）,但三者组间比较差异无统计学意义（P>0.05）;少突胶质细胞瘤1p/19q联合缺失与MGMT基因启动子甲基化呈正相关性,并且均与患者3年生存率相关（P<0.05）。结论 少突胶质细胞瘤中1p/19q联合缺失与MGMT基因启动子甲基化状态密切相关,联合检测有助于提高临床病理诊断的精确性,更好地评估预后。     

染色体1p、19q缺失检测在胶质瘤病理诊断中的意义

摘 要：［目的］ 研究染色体1p和19q的缺失在不同病理类型胶质瘤中的分布差异,评价其在胶质瘤病理鉴别诊断中的价值。［方法］ 选取经术后病理确诊的Ⅱ～Ⅲ级胶质瘤患者共134例。采用特异性扩增片段分析法检测肿瘤组织染色体1p、19q缺失情况。［结果］ 134例患者中,组织病理学认定为间变性少突胶质细胞瘤（anaplastic oligodendroglioma,AO,WHO Ⅲ级）9例（6.7%）,少突胶质细胞瘤（oligodendroglial tumor,OT,WHO Ⅱ级）15例（11.2%）,混合型胶质瘤（星形+少突）32例（23.9%）,星型细胞瘤（astrocytoma,AA）78例（58.2%）。少突胶质细胞瘤、间变性少突胶质细胞瘤、混合型胶质瘤、星型细胞瘤的1p、19q缺失率为分别为73.3%（11/15）和 66.7%（10/15）、 66.7%（6/9）和77.8%（7/9）、53.1%（17/32）和59.4%（19/32）、43.6%（34/78）和41.0%（32/78）。染色体1p和19q的缺失情况（包括完整,杂合性缺失,联合缺失）在少突胶质细胞瘤、混合型胶质瘤、星型细胞瘤的分布差异有统计学意义（P<0.05）,但在不同级别少突胶质细胞瘤中,染色体缺失差异无统计学意义。 ［结论］ 染色体1p、19q的缺失与胶质瘤病理类型相关。单纯依靠组织病理学诊断难以准确判断胶质瘤类型,检测染色体1p、19q缺失情况可作为胶质瘤病理诊断的重要参考指标。     

胶质瘤影像研究进展

Virshow最早应用胶质瘤 ( gliomas)一词来描述脑内原发性肿瘤 ,系指整个神经上皮组织来源的、包括各型胶质细胞和神经元的肿瘤。目前 ,这些肿瘤在神经影像学统称为胶质瘤 ,即广义上所称的胶质瘤。表 1　中枢神经系统肿瘤的 WHO恶性程度分级系统肿瘤组别肿瘤类型 级 级 级 级星形细胞肿瘤室管膜下巨细胞型 毛细胞型 低级别 多形性黄色瘤性星形细胞肿瘤 间变性 胶质母细胞瘤 少枝胶质瘤低级别 间变性 少枝 -星形细胞瘤低级别 间变性 室管膜肿瘤室管膜下室管膜瘤 黏液乳头状 低级别 间变性 脉络丛肿瘤乳头瘤癌 神经元…     

胶质细胞瘤染色体1p杂合性缺失：14例研究分析

背景与目的:少突胶质细胞瘤是胶质瘤中的一种独立类型,近年来的研究显示少突胶质细胞瘤存在着不同于其它胶质瘤类型的分子遗传学改变。其中最显著的就是在大多数少突胶质细胞瘤中出现染色质1p和19q的缺失。同时还发现,有染色质1p及19q缺失病例,对化疗药物敏感性增强,生存期延长,反之预后差。本研究旨在研究胶质细胞瘤染色体1P杂合性缺失的特点。方法:本文使用荧光原位杂交(FISH)技术检测了我院脑外科手术的7例少突胶质细胞瘤及7例其他颅内肿瘤病例的染色体1p。结果:7例少突胶质细胞瘤中4例有1p杂合性缺失,而其他颅内胶质瘤病例中仅有2例出现1p杂合性的缺失。另外1p杂合性缺失的4例病变均为单侧,3例为颞叶,1例为额叶;肿瘤级别上3例为少突胶质细胞瘤(WHOⅡ级),1例为间变性少突胶质细胞瘤(WHOⅢ级)。结论:本研究提示1p杂合性缺失的发生率在少突胶质细胞瘤(4/7)比其它类型胶质瘤(2/7)为高。     

少突胶质细胞瘤临床病理特征及与GFAP、VIM、p53、Ki-67表达的相关性

目的:探讨少突胶质细胞瘤的临床病理分级及与GFAP、VIM、p53、Ki-67表达的相关性。方法:对170例术后病理诊断为少突胶质细胞瘤患者的肿瘤免疫组织化学病理进行回顾性分析，研究少突胶质细胞瘤GFAP、VIM、p53、Ki-67与临床病理特征之间的关系及它们之间的相关性。所有数据采用Excel软件录入，SPSS 17.0统计软件进行数据处理，卡方检验，P＜0.05认为差异具有统计学意义。结果:根据2007年WHO中枢神经系统分类标准:少突型53例，间变少突型43例，星形-少突型55例，间变星形-少突型19例。不同病理分级少突胶质细胞瘤GFAP（P=0.035）、p53（P=0.004）、Ki-67（P=0.000）的表达不同，可能与病理分级相关。VIM（P=0.967）与不同病理分级无关。结论:少突胶质细胞瘤的不同病理分型与p53、GFAP、Ki-67的阳性表达有关，GFAP阳性表达随着肿瘤级别的增加而减少；相反地，p53、Ki-67的阳性表达随着肿瘤级别的增加而增加。     

胶质瘤诊断和预后标志物的研究进展

神经胶质瘤是中枢神经系统最常见而又最难治的恶性肿瘤,因其部位的特殊性,造成诊断困难,易复发而且难以治愈。因而寻找胶质瘤特异性的诊断和预后生物标志物变得更为重要。生物标志物是近些年来出现在医学研究领域上的热点,它作为可供客观测定和评价的一个生化或分子生物学指标,反映机体当前所处的生物学状态及进程。随着分子生物学新技术的应用,已发现一系列对诊断、鉴别诊断和治疗有实用价值的生物学标志物。本文总结了近几年关于胶质瘤诊断和预后标志物的一些研究进展,比如BRAF融合基因在毛细胞星形细胞瘤中的作用,染色体1p/19q,6O-甲基鸟嘌呤-DNA甲基转移酶(MGMT)甲基化状态和异柠檬酸脱氢酶(IDH)在弥漫性胶质瘤中的作用。这些标志物是近几年恶性胶质瘤研究的热点,对进一步完善胶质瘤的诊断、鉴别诊断、指导预后和开辟有效的分子靶向治疗有重要的指导意义。     

Ⅱ级星形胶质细胞瘤的预后相关分子分析

星形胶质细胞瘤Ⅱ级是最常见的低级别胶质瘤，手术是主要治疗手段。可能由于不同的基因亚型导致了Ⅱ级星形胶质细胞瘤临床病程和预后差异较大。星形胶质细胞瘤分子病理学方面，报道较多的基因表达改变包括：细胞增殖与凋亡有关的分子Ki67、Fas／FasL；细胞周期调节通路TP53／P21，P27，P14：生长因子及其受体，包括PDGF配体和受体等；血管生成通路1：Cox-2，iNOS，VEGF；血管生成通路2：Angiopoietin．Tie2：其它与血管生成有关的基因如ING4；与肿瘤浸润有关的是基质金属蛋白酶MMP-2，MMP-9，Tenascin-C，Fn14等：另外还有DCC等。以上相关分子表达与星形胶质细胞瘤的发展和预后有关，但有肯定性结论的还不多，本文复习文献并分析这些相关分子表达与病人预后的关系。     

Immunohistochemistry on IDH 1/2, ATRX,p53 and Ki-67 substitute molecular genetic testing and predict patient prognosis in grade III adult diffuse gliomas

The molecular subgrouping of diffuse gliomas was recently found to stratify patients into prognostically distinct groups better than histological classification. Among several molecular parameters, the key molecules for the subtype diagnosis of diffuse gliomas are IDH mutation, 1p/19q co-deletion, and ATRX mutation; 1p/19q co-deletion is undetectable by immunohistochemistry, but is mutually exclusive with ATRX and p53 mutation in IDH mutant gliomas. Therefore, we applied ATRX and p53 immunohistochemistry instead of 1p/19q co-deletion analysis. The prognostic value of immunohistochemical diagnosis for Grade III gliomas was subsequently investigated. Then, the same immunohistochmical diagnostic approach was expanded for the evaluation of Grade II and IV diffuse glioma prognosis. The results indicate immunohistochemical analysis including IDH1/2, ATRX, p53, and Ki-67 index is valuable for the classification of diffuse gliomas, which is useful for the evaluation of prognosis, especially Grade III gliomas and lower-grade gliomas (i.e., Grade II and III).     

Molecular diagnostics as a tool to personalize treatment in adult glioma patients

Gliomas, the most frequent primary brain tumors in humans, form a heterogeneous group, encompassing many different histological types and malignancy grades. Within this group, the diffuse infiltrative gliomas are by far the most common in adults. The major representatives in this subgroup are the diffuse astrocytic, oligodendroglial, and mixed oligo-astrocytic tumors. Especially in these diffuse gliomas, the role of molecular diagnostics is rapidly increasing. After summarizing the most relevant genetic aberrations and pathways in these tumors detected up till now, this review will discuss the clinical relevance of this information. Several molecular markers have been identified in diffuse gliomas that carry diagnostic and prognostic information. In addition, some of these and other markers predict the response of these gliomas to particular (chemo)therapeutic approaches. The techniques used to obtain this molecular information, as well as the advantages and disadvantages of the different techniques will be discussed. Finally, future perspectives will be presented with regard to the contribution of molecular diagnostics to tailor-made therapy in glioma patients.     

The Integrated Histopathologic and Molecular Approach to Adult-type Diffuse Astrocytomas: Status of the Art,Based on the 2021 WHO Classification of Central Nervous System Tumors

The 2021 World Health Organization (WHO) Classification of Tumors of the Central Nervous System (CNS) improved our understanding of the brain neoplasm biology. In more details, differences between diffuse gliomas that primarily occur in adults and those that primarily occur in children have been identified by the terms “adult-type” and “pediatric-type” diffuse gliomas. More importantly, both diagnostic and grading criteria for adult-type diffuse astrocytomas have been modified, by adopting novel molecular markers: diffuse astrocytomas, IDH-mutant have been grouped into a single entity and graded as CNS WHO grades 2, 3, or 4, with the assignment of Grade 4 in the presence of CDKN2A/B homozygous deletion, regardless of the histology [1]. Additionally, at least one of the following genetic alterations has been considered as sufficient to confer to astrocytomas, IDH wild type, a CNS WHO grade 4: i) TERT promoter mutation, ii) EGFR gene amplification, iii) combined gain of whole chromosome 7 and loss of whole chromosome 10 [+7/−10]. However, histology remains the solid basis to support these new complementary molecular data, and an integrated diagnosis is highly recommended.     

Integrating multiple-level molecular data to infer the distinctions between glioblastoma and lower-grade glioma

Glioblastomas (GBMs) and lower-grade gliomas (LGGs) are the most common malignant brain tumors. Despite extensive studies that have suggested that there are differences between the two in terms of clinical profile and treatment, their distinctions on a molecular level had not been systematically analyzed. Here, we investigated the distinctions between GBM and LGG based on multidimensional data, including somatic mutations, somatic copy number variants (SCNVs), gene expression, lncRNA expression and DNA methylation levels. We found that GBM patients had a higher mutation frequency and SCNVs than LGG patients. Differential mRNAs and lncRNAs between GBM and LGG were identified and a differential mRNA–lncRNA network was constructed and analyzed. We also discovered some differential DNA methylation sites could distinguish between GBM and LGG samples. Finally, we identified some key GBM- and LGG-specific genes featuring multiple-level molecular alterations. These specific genes participate in diverse functions; moreover, GBM-specific genes are enriched in the glioma pathway. Overall, our studies explored the distinctions between GMB and LGG using a comprehensive genomics approach that may provide novel insights into studying the mechanism and treatment of brain tumors.     

Identification of Hedgehog pathway responsive glioblastomas by isocitrate dehydrogenase mutation

The Hedgehog (Hh) pathway regulates the growth of a subset of adult gliomas and better definition of Hh-responsive subtypes could enhance the clinical utility of monitoring and targeting this pathway in patients. Somatic mutations of the isocitrate dehydrogenase (IDH) genes occur frequently in WHO grades II and III gliomas and WHO grade IV secondary glioblastomas. Hh pathway activation in WHO grades II and III gliomas suggests that it might also be operational in glioblastomas that developed from lower-grade lesions. To evaluate this possibility and to better define the molecular and histopathological glioma subtypes that are Hh-responsive, IDH genes were sequenced in adult glioma specimens assayed for an operant Hh pathway. The proportions of grades II–IV specimens with IDH mutations correlated with the proportions that expressed elevated levels of the Hh gene target PTCH1. Indices of an operational Hh pathway were measured in all primary cultures and xenografts derived from IDH-mutant glioma specimens, including IDH-mutant glioblastomas. In contrast, the Hh pathway was not operational in glioblastomas that lacked IDH mutation or history of antecedent lower-grade disease. IDH mutation is not required for an operant pathway however, as significant Hh pathway modulation was also measured in grade III gliomas with wild-type IDH sequences. These results indicate that the Hh pathway is operational in grades II and III gliomas and glioblastomas with molecular or histopathological evidence for evolvement from lower-grade gliomas. Lastly, these findings suggest that gliomas sharing this molecularly defined route of progression arise in Hh-responsive cell types.     

<Emphasis Type="Italic">MGMT</Emphasis> promoter methylation in malignant gliomas

The O⁶-methylguanine-DNA methyltransferase (MGMT) gene is located at chromosome 10q26 and codes for a DNA repair enzyme that—if active—can counteract the effects of alkylating chemotherapy. Malignant gliomas often have the MGMT gene inactivated due to aberrant methylation of its promoter region. The assessment of the MGMT promoter methylation status has become of clinical relevance as a molecular marker associated with response to alkylating chemotherapy and prolonged survival of glioblastoma patients. MGMT promoter methylation testing is also on the merge of being used as a marker for patient selection within clinical trials, e.g., the current CENTRIC trial that is specifically focusing on patients with MGMT promoter-methylated glioblastomas. In anaplastic gliomas, MGMT promoter methylation is a favorable prognostic marker independent of the type of therapy, i.e., radio- or chemotherapy. This occurrence might be associated with the high incidence of other prognostically favorable molecular markers in these tumors, such as IDH1 mutation, 1p/19q deletion or yet to be identified novel aberrations. A variety of different methods are being used to assess MGMT promoter methylation in clinical samples, which may give rise to inter-laboratory variations in test results. Immunohistochemical determination of MGMT protein expression has not proven reliable for diagnostic purposes. This brief review article aims to summarize the main aspects of MGMT promoter methylation testing in contemporary neuro-oncology, in particular its value as a clinically useful molecular marker, putting it into the context of other molecular markers of clinical use in gliomas of adult patients.     

Mathematical modeling of noise and discovery of genetic expression classes in gliomas

The microarray array experimental system generates noisy data that require validation by other experimental methods for measuring gene expression. Here we present an algebraic modeling of noise that extracts expression measurements true to a high degree of confidence. This work profiles the expression of 19 200 cDNAs in 35 human gliomas; the experiments are designed to generate four replicate spots/gene with switching of probes. The validity of the extracted measurements is confirmed by: (1) cluster analysis that generates a molecular classification differentiating glioblastoma from lower-grade tumors and radiation necrosis; (2) By what other investigators have reported in gliomas using paradigms for assaying molecular expression other than gene profiling; and (3) Real-time RT-PCR. The results yield a genetic analysis of gliomas and identify classes of genetic expression that link novel genes to the biology of gliomas.