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。     

胶质瘤染色体1p和19q杂合性缺失与O6-甲基鸟嘌呤DNA甲基转移酶p53和Ki-67蛋白表达的关系

目的 探讨胶质瘤染色体1p和19q杂合性缺失(LOH)与O6-甲基鸟嘌呤DNA甲基转移酶(MGMT)、p53和Ki-67蛋白表达的关系.方法 采集146例胶质瘤(45例少突胶质细胞瘤、42例少突星形细胞瘤和59例星形细胞瘤)的肿瘤组织和血液标本,采用聚合酶链反应结合变性高效液相色谱技术检测染色体1p和19q LOH,免疫组化法检测肿瘤组织中MGMT、p53和Ki-67蛋白的表达,并进一步分析其与胶质瘤临床病理特征的关系.结果 少突胶质细胞肿瘤和星形细胞瘤中,1p LOH的发生率分别为59.8％和33.9％,差异有统计学意义(P=0.002);1p和19q LOH的发生率分别为42.5％和16.9％,差异有统计学意义(P=0.001).MGMT低表达和Ki-67高表达多发生于少突胶质细胞肿瘤中,发生率分别为65.5％和54.0％,而p53高表达多发生于星形细胞瘤和少突星形细胞瘤中,发生率为75.2％.在87例少突胶质细胞肿瘤中,1p LOH和MGMT蛋白低表达多发生于Ⅱ级少突胶质细胞肿瘤中,发生率分别为72.5％和87.5％,而p53和Ki-67蛋白高表达多发生于Ⅲ级少突胶质细胞肿瘤中,发生率分别为83.0％和76.6％.1p和19q LOH在非颞叶和颞叶肿瘤的发生率分别为55.6％和21.2％(P=0.002).1p LOH与19q LOH、MGMT蛋白表达与p53蛋白表达、MGMT蛋白表达与Ki-67蛋白表达、1p和19q LOH与p53蛋白表达、1p LOH与Ki-67蛋白表达均有关(均P＜0.05).结论 1p和19q LOH及MGMT、p53和Ki-67的蛋白表达与胶质瘤的临床病理学特征有关,检测其LOH状态和表达水平对胶质瘤的诊断和治疗具有指导作用.     

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。     

弥漫性较低级别胶质瘤的整合性分子病理分型研究进展*

弥漫性较低级别胶质瘤包含WHOⅡ级和Ⅲ级的星形细胞瘤、少突胶质细胞瘤和少突星形细胞瘤,其临床表现具有高度可变性,目前的组织病理学无法准确地预测其预后。近年来,胶质瘤分子病理取得了重大进展,已经发现一系列与胶质瘤临床特征和预后密切相关的分子标志物如异柠檬酸脱氢酶（isocitrate dehydrogenase ,IDH ）突变、染色体1p/ 19q 共缺失、ATRX 基因突变、TERT启动子突变、MGMT 启动子甲基化等。在此基础上,结合这些分子标志物对弥漫性较低级别胶质瘤进行整合性分子病理分型的研究相继开展,且这些研究的结果一致表明,整合性分子病理分型能够更好地预测弥漫性较低级别胶质瘤的预后和指导治疗。本研究对弥漫性较低级别胶质瘤的整合性分子病理分型研究进展进行综述。      

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。     

IDH突变和1p/19q共缺失型少突胶质细胞瘤临床病理特征和预后分析

目的探讨I D H突变和1p/19q共缺失型少突胶质细胞瘤的临床病理特征及预后相关影响因素。方法收集54例IDH突变和1p/19q共缺失型少突胶质细胞瘤病例,分析其临床病理特点,包括年龄、组织学分级和肿瘤部位等因素对无进展生存期和总生存期的影响。结果 54例患者中,肿瘤发生于1个脑叶者46例,发生于2个脑叶以上者8例。肿瘤组织学WHO分级2级12例,3级42例。FISH检测显示54例均为1p/19q共缺失;免疫组织化学检测显示Olig2均为弥漫强阳性;GFAP均为阳性;p53有6例强阳性;48例患者ATRX未缺失;Ki-67增殖指数5%～60%。Sanger测序显示54例均发生IDH基因突变（40例为IDH1突变,14例为IDH2突变）,33例发生TERT启动子突变。16例在治疗过程中发生复发及转移。单因素分析显示,手术后复发转移间隔时间超过2年可以延长患者无进展生存和总生存期。54例患者平均无进展生存期33.5个月,平均总生存期40.7个月。结论 IDH突变和1p/19q共缺失型少突胶质细胞瘤术后联合精准放化疗降低了进展风险,手术后复发转移间隔时间与该型患者预后相关。     

胃癌组织中PDCD4基因的表达和甲基化水平及其临床意义

目的 观察胃癌组织中抑癌基因PDCD4启动子区甲基化状态及其对PDCD4表达水平的影响并探讨其临床意义。方法 通过免疫组织化学、Western blot法检测胃癌组织中PDCD4蛋白的表达；RT-PCR法检测PDCD4 mRNA的表达；甲基化特异性PCR（MSP）法检测PDCD4启动子区甲基化水平。分析PDCD4表达水平以及启动子甲基化水平与胃癌患者临床病理特征之间的相关性。结果 胃癌组织中PDCD4蛋白及mRNA表达水平均显著降低（P<0.05），甲基化作用显著增强（P<0.05）。PDCD4蛋白表达缺失与胃癌的分化、临床分期以及淋巴结转移密切相关（P<0.05）；PDCD4高甲基化与胃癌的淋巴结转移、临床分期密切相关（P<0.05）。PDCD4甲基化水平与PDCD4蛋白以及mRNA表达水平均呈负相关（P<0.05）。结论 胃癌组织中PDCD4表达水平显著降低，并与胃癌发展相关，启动子区高甲基化可能是PDCD4表达缺失的原因。     

少突胶质细胞瘤神经系统外转移1例报告并文献复习

<正>少突胶质细胞瘤为成人型弥漫性胶质瘤的一个亚型,染色体1p/19q联合缺失为少突胶质细胞瘤的关键变异,提示预后相对良好。少突胶质细胞瘤的神经系统外转移极为罕见,本例为我科收治的1例脑少突胶质细胞瘤（WHOⅢ级）并颅骨、脊柱、骶骨、肋骨、锁骨多发转移患者。现报告如下以加深相关认识。1病例资料患者,男,因“阵发性头颈部疼痛”于2018年09月入院。入院查体：神清语利,问答切题,双侧瞳孔等大等圆直径3.0mm、双侧对光反射均灵敏,神经系统专科查体及心肺腹部查体均未查及异常。     

胶质瘤中MKK7与c-Jun磷酸化的表达及其相关性

目的 探讨胶质瘤中MKK7和c-Jun磷酸化（p-c-Jun）的表达及意义，分析两者表达的相关性。方法 选取弥漫型星形细胞瘤（15例）、少突胶质细胞瘤（5例）、间变性星形细胞瘤（11例）、间变性少突胶质细胞瘤（8例）、胶质母细胞瘤（53例）及其瘤旁正常脑组织（25例）共117例，采用免疫组织化学法检测MKK7、c-Jun及p-c-Jun的表达。体外培养神经胶质瘤细胞株U87，用脂质体转染MKK4-siRNA、MKK7-siRNA和对照siRNA，48 h后Western blot检测MKK7、c-Jun及p-c-Jun的表达水平。结果 胶质母细胞瘤中p-c-Jun及MKK7的表达均明显高于其他组织学类型胶质瘤及胶质母细胞瘤瘤旁正常脑组织中的表达（P=0.000, P=0.000）。随着胶质瘤WHO分级的升高，p-c-Jun及MKK7的表达增高，且与WHO分级呈明显正相关（r=0.494, P=0.000; r=0.606, P=0.000）。胶质瘤及胶质母细胞瘤瘤旁正常脑组织中MKK7与p-c-Jun的表达存在正相关关系（r=0.387, P=0.000）。沉默神经胶质瘤细胞株U87 MKK7表达抑制了c-Jun磷酸化水平。结论 MKK7可以通过调控JNK/c-Jun活性进而促进胶质母细胞瘤的发生。     

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。     

Chemoradiation for anaplastic oligodendrogliomas: clinical outcomes and prognostic value of molecular markers

Combination of procarbazine, lomustine and vincristine (PCV) with radiation therapy (RT) has been associated with longer survival in patients with anaplastic oligodendroglioma (AO) and anaplastic oligoastrocytoma (AOA), especially in those with chromosome 1p/19q codeletion. We report a multicenter retrospective study of 84 consecutive adult patients with AO and AOA treated with RT plus concomitant and adjuvant temozolomide (TMZ) between February 2004 and January 2011. Correlations between chromosome 1p/19q codeletion, isocitrate dehydrogenase1 (IDH1) mutation, and O-6-methylguanine-DNA methyltransferase (MGMT) promoter methylation with survival outcomes have been analyzed. For all 84 patients the median overall survival (OS) and progression-free survival rates were 55.6 and 45.2 months, respectively. Grade 3 or 4 hematological toxicity occurred in 17 % of patients. Chromosome 1p/19q codeletion was detected in 57 %, IDH1 mutation in 63 %, and MGMT promoter methylation in 74 % of evaluable patients. In multivariate analysis the presence of chromosome 1p/19q codeletion was associated with significant survival benefit (median OS 34 months in noncodeleted tumors and not reached in codeleted tumors; HR 0.16, 95 % CI 0.03–0.45; P = 0.005). IDH1 mutation was also of prognostic significance for longer survival (P = 0.001; HR 0.20, 95 % 0.06–0.41), whereas MGMT promoter methylation was only of borderline significance. The study indicates that RT with concomitant and adjuvant TMZ is a relatively safe treatment associated with longer survival in patients with 1p/19q codeleted and IDH1 mutated tumors. Results from ongoing randomized studies will be essential to clarify if RT plus TMZ may provide survival as good as or better than RT combined with PCV for patients with AO and AOA.     

Molecular genetic markers as predictors of response to chemotherapy in gliomas

PURPOSE OF REVIEW: This review summarizes recent studies on applications of molecular markers such as chromosome 1p/19q codeletion and MGMT status in the treatment of glioma. RECENT FINDINGS: Prospective trials confirmed that 1p/19q codeletion represents a strong and independent favourable prognostic factor in anaplastic oligodendroglial tumours. Other retrospective studies have suggested that 1p/19q loss is also predictive of chemosensitivity to alkylating agents (nitrosoureas and temozolomide) in low-grade gliomas. Recent reports have provided evidence that 1p and 19q deletions are mediated by unbalanced translocation. The targeted genes remain to be identified, however. Promoter methylation of MGMT gene silencing has been shown to predict benefit from chemotherapy in glioblastoma. MGMT promoter methylation and low expression of MGMT-encoded protein are frequently observed in low-grade gliomas and anaplastic oligodendroglial tumours. In such tumours, however, preliminary studies have yielded contradictory results on the predictive value of MGMT status regarding objective response to chemotherapy and correlation with 1p/19q deletion. SUMMARY: There is mounting evidence that 1p/19q deletion and MGMT inactivation are relevant prognostic markers and predictors of chemosensitivity in gliomas. Although such markers remain to be formally validated by ongoing and planned prospective trials, it is likely that they will soon become essential for optimizing treatment decisions.     

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.     

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 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.     

Gene amplification is a poor prognostic factor in anaplastic oligodendrogliomas

Various gene amplifications have been observed in gliomas. Prognostic-genomic correlations testing simultaneously all these amplified genes have never been conducted in anaplastic oligodendrogliomas. A set of 38 genes that have been reported to be amplified in gliomas and investigated as the main targets of amplicons were studied in a series of 52 anaplastic oligodendrogliomas using bacterial artificial chromosome-array based comparative genomic hybridization and quantitative polymerase chain reaction. Among the 38 target genes, 15 were found to be amplified in at least one tumor. Overall, 27% of anaplastic oligodendrogliomas exhibited at least one gene amplification. The most frequently amplified genes were epidermal growth factor receptor (EGFR) and cyclin-dependent kinase 4/sarcoma amplified sequence (CDK4/SAS) in 17% and 8% of anaplastic oligodendrogliomas, respectively. Gene amplification and codeletion of chromosome arms 1p/19q were perfectly exclusive (p = 0.005). In uni- and multivariate analyses, gene amplification was a negative prognostic factor for progression-free survival and overall survival in anaplastic oligodendrogliomas, providing complementary information to the classic prognostic factors identified in anaplastic oligodendrogliomas (extent of surgery, KPS, and chromosome arms 1p/19q status).