低级别胶质肿瘤的1p/19q缺失研究

背景与目的：近几年来,少枝胶质细胞瘤,特别是有染色体1p/19q的联合缺失者被证实对烷化剂化疗敏感,成为预后良好的标志物。本实验旨在研究低级别胶质瘤中1p/19q的联合缺失率和与标本中1p/19q的缺失百分比相关的分子病理特征。方法：搜集北京天坛医院低级别胶质瘤标本25例,应用免疫荧光原位杂交（fluorescence in situ hybridization,FISH）的方法对1p36和19q13的缺失程度进行定量分析,统计其在低级别胶质瘤中的联合缺失率,并应用Spearman秩相关分析方法分析标本中1p36、19q13缺失百分比与P170、MGMT、MMP-9、PTEN、EGFR、P53、VEGF、Ki-67、TOPO-Ⅱ、GST-π的分子病理结果的关系。结果：在25例低级别胶质瘤标本中,星形细胞瘤10例,少枝胶质细胞瘤3例,少枝星形细胞瘤12例。在星形细胞瘤、少枝胶质瘤和少枝星形细胞瘤中,1p/19q联合缺失率分别为40%、67%和50%。1p36、19q13的缺失程度与MGMT表达呈负相关,（P分别为0.042和0.015）,1p36的缺失程度与GST-π表达呈负相关（P=0.024）。结论：在低级别胶质瘤中,1p/19q的联合缺失率与国外报道相似,MGMT、GST-π的低表达可能与1p、19q的缺失有关。     

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。     

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。     

MDM2和p53在反应性及肿瘤性星形胶质细胞中的表达

目的：检测MDM2和p53蛋白在星形胶质细胞反应性增生与星形胶质细胞瘤中的表达，探讨二者在胶质瘤形成和发展中的作用及其相关性。方法：应用组织芯片和免疫组化染色技术检测正常脑组织、星形胶质细胞反应性增生、低级别（Ⅰ-Ⅱ级）和高级别（Ⅲ-Ⅳ级）星形胶质细胞瘤中MDM2和p53蛋白的表达情况。结果：正常脑组织中MDM2和p53蛋白均呈阴性表达；反应性增生组、低级别肿瘤组及高级别肿瘤组中MDM2蛋白的阳性率分别为32.7％（16／49）、59．2％（29／49）、80．0％（40／50）；p53蛋白的阳性率分别为27．3％（12／49）、57．1％（28／49）、82．0％（41／50）。二者阳性表达率均随着病变恶性程度的增加而升高，MDM2和p53在各实验组间的比较差异均有统计学意义（P〈0．05）；且MDM2和p53表达密切相关（P〈0．05）。结论：MDM2和p53在星形胶质细胞反应性增生及星形胶质细胞瘤中均呈不同程度的过度表达，且随着病变恶性程度的增加表达水平增高，MDM2扩增和p53突变是胶质瘤发生的早期事件，二者的联合检测可能会对星形胶质细胞反应性增生与低级别胶质细胞瘤的鉴别诊断以及星形胶质细胞瘤的早期诊断提供一定的依据。     

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。     

Ki-67、p53在脑胶质瘤中的表达及意义

目的探讨Ki-67和p53与脑胶质瘤分级的关系。方法采用免疫组化SP法检测60例脑胶质瘤标本和10例正常脑组织标本Ki-67和p53的表达。结果 Ki-67和p53在正常脑组织与脑胶质瘤中的表达差异均有统计学意义（Ki-67：χ2=13.081,P=0.004;p53：χ2=11.667,P=0.009）;Ⅰ～Ⅱ级胶质细胞瘤与高度恶性Ⅲ～Ⅳ级胶质细胞瘤Ki-67和p53的表达差异均有统计学意义（Ki-67：χ2=12.589,P=0.006;p53：χ2=12.721,P=0.005）。结论脑胶质瘤中Ki-67及p53的阳性表达率与其恶性度相关,均可作为判断胶质瘤恶性程度的指标。     

星形细胞瘤中PTEN、p53及Ki-67的表达与肿瘤细胞增殖及分级的关系

 目的　探讨星形细胞瘤中PTEN、p53及Ki-67的表达水平及其与肿瘤细胞增殖及分级的关系。方法　采用免疫组织化学方法检测68例星形细胞瘤中PTEN、p53及Ki-67的表达水平。结果　星形细胞瘤中PTEN、p53及Ki-67的表达率分别是54.4 %、45.6 %及48.5 %,随着肿瘤级别增加,PTEN的表达率下降,而p53、Ki-67的表达率上升,Spearman等级相关分析显示PTEN的表达与星形细胞瘤的分级呈负相关,p53、Ki-67的表达与分级呈正相关。PTEN阳性表达的37例星形细胞瘤标本中,Ki-67的阳性率是24.3 %;而在PTEN阴性的31例标本中,Ki-67的阳性率是77.4 %,PTEN表达与Ki-67表达呈负相关。结论　PTEN的表达与星形细胞瘤的分级呈负相关,Ki-67、p53的表达与星形细胞瘤组织病理分级呈正相关。PTEN在一定程度上可以抑制肿瘤细胞的增殖。     

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。     

不同级别胶质瘤中p53蛋白与O~6-甲基鸟嘌呤-DNA甲基转移酶表达的相关性

目的探讨不同级别胶质瘤中p53蛋白与O6-甲基鸟嘌呤-DNA甲基转移酶(MGMT)表达的相关性。方法选取2013年1月至2013年12月间行神经外科手术切除的98例脑胶质瘤组织作为研究对象,采用免疫组织化学的方法分析不同级别胶质瘤组织中p53蛋白与MGMT表达的关系。结果 MGMT在不同级别胶质瘤组织间表达无显著差异,在表达强度上差异有统计学意义(P<0.05)。p53在不同级别胶质瘤组织中的表达差异有统计学意义,在表达强度上并无明显特征。MGMT与p53在表达强度上呈负相关。结论 p53与MGMT的表达在不同级别的胶质瘤中均有一定的关系,且p53表达增强和MGMT表达减弱均对胶质瘤的发生、发展及其恶性程度产生一定的影响。     

Quantitative analysis of O<Superscript>6</Superscript>-methylguanine DNA methyltransferase (MGMT) promoter methylation in patients with low-grade gliomas

Methylation of the MGMT promoter is supposed to be a predictive and prognostic factor in glioblastoma. Whether MGMT promoter methylation correlates with tumor response to temozolomide in low-grade gliomas is less clear. Therefore, we analyzed MGMT promoter methylation by a quantitative methylation-specific PCR in 22 patients with histologically verified low-grade gliomas (WHO grade II) who were treated with temozolomide (TMZ) for tumor progression. Objective tumor response, toxicity, and LOH of microsatellite markers on chromosomes 1p and 19q were analyzed. Histological classification revealed ten oligodendrogliomas, seven oligoastrocytomas, and five astrocytomas. All patients were treated with TMZ 200 mg/m² on days 1–5 in a 4 week cycle. The median progression-free survival was 32 months. Combined LOH 1p and 19q was found in 14 patients; one patient had LOH 1p alone and one patient LOH 19q alone. The LOH status could not be determined in two patients and was normal in the remaining four. LOH 1p and/or 19q correlated with longer time to progression but not with radiological response to TMZ. MGMT promoter methylation was detectable in 20 patients by conventional PCR and quantitative analysis revealed the methylation status was between 12 and 100%. The volumetric response to chemotherapy analyzed by MRI and time to progression correlated with the level of MGMT promoter methylation. Therefore, our retrospective case series suggests that quantitative methylation-specific PCR of the MGMT promoter predicts radiological response to chemotherapy with TMZ in WHO grade II gliomas.     

Correlation of chromosomal imbalances by comparative genomic hybridization and expression of EGFR, PTEN, p53, and MIB-1 in diffuse gliomas

The histological subclassification of gliomas is increasingly assisted by the underlying molecular genetics which has major importance in guiding clinical management of the disease. However, the assessment of several molecular events for improving clinical care remains a challenge. Herein, we report on comparative genomic hybridization (CGH) and immunohistochemical (IHC) assessment of EGFR, PTEN, p53, and MIB-1 expression in 13 oligodendrogliomas (10 WHO grade II, 3 WHO grade III), one oligoastrocytoma (WHO grade III) and 23 high-grade astrocytomas (3 WHO grade III, 20 glioblastoma multiforme). The most frequent imbalances in oligodendroglial tumors including the oligoastrocytic case were, in decreasing order of frequency, +7q, -1p, and -4q and in astrocytomas +7q, -10q, +7p, -9p, -10p, +20q, and +20p. Some individual imbalances were associated with increasing numbers of chromosomal changes, that were +7q in both oligodendrogliomas and astrocytomas, and -9p, -10q, +20p, and +20q in astrocytomas. The markers p53 and MIB-1 were significantly higher expressed in astrocytomas than in oligodendrogliomas and expression levels of p53 and EGFR were inversely associated within the astrocytic group. In addition, p53 overexpression correlated positively with +7q and negatively with -1p in the oligodendroglial group whereas EGFR overexpression correlated positively with -1p in the oligodendroglial and positively with +7p and -10p in the astrocytic group. Short overall survival was significantly associated with +7p and -10q in astrocytomas. Collectively, these results contribute to the increasing clinical relevance of assessing tumor biological markers in gliomas.     

Localization of common deletion regions on 1p and 19q in human gliomas and their association with histological subtype.

Allelic alterations of chromosomes 1 and 19 are frequent events in human diffuse gliomas and have recently proven to be strong predictors of chemotherapeutic response and prolonged survival in oligodendrogliomas (Cairncross et al., 1998; Smith et al., submitted). Using 115 human diffuse gliomas, we localized regions of common allelic loss on chromosomes 1 and 19 and assessed the association of these deletion intervals with glioma histological subtypes. Further, we evaluated the capacity of multiple modalities to detect these alterations, including loss of heterozygosity (LOH), fluorescence in situ hybridization (FISH), and comparative genomic hybridization (CGH). The correlation coefficients for detection of 1p and 19q alterations, respectively, between modalities were: 0.98 and 0.87 for LOH and FISH, 0.79 and 0.60 for LOH and CGH, and 0.79 and 0.53 for FISH and CGH. Minimal deletion regions were defined on 19q13.3 (D19S412-D19S596) and 1p (D1S468-D1S1612). Loss of the 1p36 region was found in 18% of astrocytomas (10/55) and in 73% (24/33) of oligodendrogliomas (P < 0.0001), and loss of the 19q13.3 region was found in 38% (21/55) of astrocytomas and 73% (24/33) of oligodendrogliomas (P = 0.0017). Loss of both regions was found in 11% (6/55) of astrocytomas and in 64% (21/33) of oligodendrogliomas (P < 0.0001). All gliomas with LOH on either 1p or 19q demonstrated loss of the corresponding FISH probe, 1p36 or 19q13.3, suggesting not only locations of putative tumor suppressor genes, but also a simple assay for assessment of 1p and 19q alterations as diagnostic and prognostic markers.     

Molecular prognostic factors of anaplastic oligodendroglial tumors and its relationship: a single institutional review of 77 patients from China

The increased chemosensitivity of oligodendroglial tumors has been associated with loss of heterozygosity (LOH) on chromosomes 1p and 19q. Other clinical and molecular factors have also been identified as being prognostic and predictive for treatment outcome. Seventy-seven patients with anaplastic oligodendroglioma (AO) or anaplastic oligoastrocytoma (AOA), treated in Beijing Tiantan Hospital from 2006 through 2008, were reviewed. LOH 1p, LOH 19q, IDH1 mutation, O(6)-methylguanine-DNA methyltransferase (MGMT) promoter methylation, and protein expression level of MGMT, P53, EGFR, and Ki-67 were evaluated. Age at diagnosis, LOH 1p and 19q, IDH1 mutation, P53 expression level, reoperation when progression, and adjuvant chemotherapy were statistically significant factors for overall survival (OS) in univariate analysis. Further multivariate analysis showed that age at diagnosis (P = .010), LOH 1p and 19q (P = .016), IDH1 mutation (P = .011), and reoperation after progression (P = .048) were independent predictors for longer survival in these patients. Nonrandom associations were found between LOH 1p and LOH 19q, MGMT promoter methylation and LOH 1p or 19q, IDH1 mutation and LOH 1p and 19q, IDH1 mutation and MGMT promoter methylation, whereas mutual exclusion was found between MGMT promoter methylation and MGMT expression level. The present study confirmed that age at diagnosis, LOH 1p and 19q, IDH1 mutation, and reoperation after progression were independent significant prognostic factors for patients with anaplastic oligodendroglial tumors. Inter-relationship between LOH 1p, LOH 19q, IDH1 mutation, MGMT promoter methylation, and MGMT expression level were also revealed. Future clinical trials for AO and AOA should consider the molecular alterations of patients.     

Correlation of histology and molecular genetic analysis of 1p, 19q, 10q, TP53, EGFR, CDK4, and CDKN2A in 91 astrocytic and oligodendroglial tumors.

PURPOSE: The histological diagnosis of human gliomas is of great importance for estimating patient prognosis and guiding therapy but suffers from being subjective and, therefore, variable. We hypothesized that molecular genetic analysis could provide a more objective means to classify tumors and, thus, reduce diagnostic variability. EXPERIMENTAL DESIGN: We performed molecular genetic analysis on 91 nonselected gliomas for 1p, 19q, 10q, TP53, epidermal growth factor receptor, and cyclin-dependent kinase 4 abnormalities and compared with the consensus diagnoses established among four independent neuropathologists. RESULTS: There were six astrocytomas, seven anaplastic astrocytomas, 45 glioblastomas, 21 oligodendrogliomas, eight anaplastic oligodendrogliomas, three oligoastrocytomas, and one anaplastic oligoastrocytoma. Twenty-nine cases had either 1p or 19qloss of heterozygosity (LOH) while retaining both copies of 10q, of which 25 (86%) were histologically oligodendroglioma, anaplastic oligodendroglioma, oligoastrocytoma, or anaplastic oligoastrocytoma. As for the oligodendroglial tumors, unanimous agreement of the initial diagnoses was almost restricted to those cases with combined 1p/19qLOH, whereas all nine tumors without 1p loss initially received variable diagnoses. Interestingly, TP53 mutation was inversely related to 1pLOH in all gliomas (P = 0.0003) but not 19qLOH (P = 0.15). CONCLUSIONS: These data demonstrate that molecular genetic analysis of 1p/19q/10q/TP53 has significant diagnostic value, especially in detecting oligodendroglial tumors. In addition, 1pLOH and TP53 mutations in gliomas may be markers of oligodendroglial and astrocytic pathways, respectively, which may separate gliomas with the same histological diagnosis, especially oligodendroglial tumors and glioblastomas. Testing for those molecular genetic alterations would be essential to obtain more homogeneous sets of gliomas for the future clinical studies.     

MDM2 and p53 expression in gliomas: a multivariate survival analysis including proliferation markers and epidermal growth factor receptor.

p53 and the murine double minute 2 (MDM2) oncoprotein expression was evaluated in paraffin-embedded tissue from 61 patients with central nervous system gliomas (53 astrocytomas and eight oligodendrogliomas) and related to proliferation-associated markers [i.e. proliferating cell nuclear antigen (PCNA), Ki-67 and nuclear organizer regions (NORs)] and epidermal growth factor receptor (EGFR). We used the monoclonal antibodies PC-10, MIB-1, DO-1, 1B1O and EGFR 113 and the colloid silver nitrate (AgNOR) technique. MDM2 and p53 were co-expressed in 28% of cases. A p53-positive/MDM2-negative phenotype was observed in 15% and a p53-negative/MDM2-positive phenotype in 20% of cases. There was a positive correlation of p53 and MDM2 expression with grade and proliferation indices. Univariate analysis in the group of diffuse astrocytomas showed that older age, high histological grade, high PCNA labelling index (LI) and high AgNOR score were associated with reduced overall survival (P < 0.05). p53 LI, Ki-67 LI, AgNOR score, tumour location and grade influenced disease-free survival (P < 0.05), whereas the only parameters affecting post-relapse survival were histological grade and Ki-67 LI (P < 0.1). Multivariate analysis revealed that age, radiotherapy, PCNA LI and p53 LI were the independent predictors of overall survival. p53 LI, Ki-67 LI, MDM2 LI, EGFR LI, grade and type of therapy were independent predictors of disease-free survival, and grade was the only independent predictor of post-relapse survival. Our results indicate that p53 LI and MDM2 LI, EGFR expression as well as proliferation markers (PCNA and Ki-67) are useful indicators of overall and disease-free survival in diffuse astrocytoma patients.