脑胶质瘤P16基因分子病理研究

目的：检测１５例脑胶质瘤中Ｐ１６基因及蛋白的存在状况。方法：用复合ＰＣＲ和免疫组织化学技术检测１５例脑胶质瘤。结果：显示Ｐ１６基因与Ｐ１６蛋白丢失率均为６０．０％（９／１５）；Ｐ１６基因和蛋白丢失主要见于Ⅲ级（８５．７％）和Ⅳ级（１００％）脑胶质瘤。结论：本文结果间接提示Ｐ１６基因和蛋白的丢失可能与脑胶质瘤的发生和演化有关。     

细胞周期依赖激酶抑制基因2A/B纯合缺失在组织病理2或3级脑胶质瘤中的临床意义

目的 细胞周期蛋白依赖激酶抑制基因2A/B（CDKN2A/B） 纯合缺失在较低级别胶质瘤（2或3级）中罕见，新版WHO分类将其定为恶性度最高4级。该研究旨在系统报道CDKN2A/B纯合缺失在较低级别胶质瘤中的临床特点、预后及相关功能通路。方法 收集473例有CDKN2A/B纯合缺失、临床和预后信息的较低级别胶质瘤患者，对发生率、临床特点及预后统计分析；收集27例新鲜肿瘤标本（13例CDKN2A/B纯合缺失），通过Ki-67和CD31免疫组织化学分析细胞增殖和血管增生；在1 116例胶质瘤RNA测序数据中对CDKN2A/B纯合缺失的相关功能和通路进行分析。结果 CDKN2A/B纯合缺失在较低级别胶质瘤中发生率为7.2%（34/473），该缺失在年龄偏大、星形细胞瘤、3级、近全切及IDH野生型患者中发生率更高（均P<0.05）。在IDH突变型或野生型较低级别胶质瘤中，CDKN2A/B纯合缺失均与患者更短的总生存期和无进展生存期相关。缺失型标本Ki-67(P=0.045)和CD31(P=0.058)蛋白表达高于野生型。生物信息学显示CDKN2A/B纯合缺失激活DNA复制、修复和细胞周期等功能和通路。结论 CDKN2A/B纯合缺失与较低级别胶质瘤患者差的预后和恶性表型有关，该类患者临床应积极治疗。     

IFN-β裸DNA对人脑胶质瘤生长的抑制作用

目的探讨β干扰素(IFN-β)基因对人脑胶质瘤生长的抑制作用,以及人IFN-β裸DNA治疗人脑胶质瘤的可行性.方法建立裸鼠SHG44胶质瘤模型,用脂质体包埋法将含IFN-β基因的真核表达载体(pSV2IFN β)注入裸鼠皮下SHG44脑胶质瘤,观察肿瘤生长情况并计算肿瘤体积,通过免疫组化、原位末端转移酶标记(TUNEL)染色以及瘤体坏死区计数检测,了解IFN-β基因对人脑胶质瘤生长的抑制作用.结果 IFN-β在荷瘤裸鼠瘤体内获得表达,裸鼠皮下胶质瘤生长受到抑制,并诱导SHG44胶质瘤细胞凋亡.结论 IFN-β裸DNA能够抑制人脑胶质瘤生长,该实验为IFN-β基因治疗人脑胶质瘤的应用奠定了初步基础.     

小儿脑胶质瘤p16基因的表达

目的：检测２０例小儿脑软质瘤中Ｐ１６基因及其蛋白的存在情况。方法用聚合酶链式反应－单链构象多态性分析和免疫组织化学技术检测了２０例１－１４岁小儿脑胶质瘤。成果显示Ｐ１６基因和Ｐ１６蛋白的丢失率分别为５０％（１０／２０％）及（５／２０）。结论本结果提示Ｐ１６基因和蛋白缺失可能与部分小儿脑有质瘤发生,发展有关。     

U251胶质瘤荷瘤鼠皮下模型的建立及其表皮生长因子受体通路成员异常表达

目的建立稳定可靠的荷瘤鼠皮下U251胶质瘤实验动物模型，使其良好地用于胶质瘤分子机制的研究。方法取生长状态良好的U251胶质瘤细胞悬液按1×10^6个细胞／50μl接种于10只荷瘤鼠腹腔皮下，待其成瘤后将肿瘤组织块接种于20只实验鼠，观察并记录肿瘤皮下生长情况，于成瘤后第5周处死荷瘤鼠检测是否存在肿瘤远处转移；同时对肿瘤组织行HE和免疫组织化学染色检测胶质瘤的病理学特征，观察表皮生长因子受体、磷酰肌醇3-激酶和丝氨酸／苏氨酸蛋白激酶-2基因阳性表达率，结果与体外培养的U251胶质瘤细胞系的基因异常表达进行比较。结果细胞悬液接种可成功获得皮下U251胶质瘤模型，但潜伏期延长（2～3周），成功率低（6／10）；若将其生成的肿瘤组织块再次接种于荷瘤鼠皮下则可获得高效、稳定的成瘤率（20／20）且潜伏期明显缩短（3d-5d）。荷瘤鼠生长状态良好，无恶病质变化，未发生其他脏器转移。大体标本观察显示，肿瘤体积〉750mm^3时其内部多见坏死伴囊性变，部分肿瘤尚有脂肪浸润或纤维化；肿瘤有假包膜形成，瘤体部分呈鱼肉状，是胶质瘤生发和再移植取材的部位。免疫组织化学检测显示，荷瘤鼠皮下胶质瘤组织和体外培养的U251胶质瘤细胞对表皮生长因子受体、磷酰肌醇3-激酶以及丝氨酸／苏氨酸蛋白激酶-2基因通路主要成员的基因表达情况相似。结论将U251胶质瘤细胞悬液接种于荷瘤鼠皮下形成的胶质瘤再移植到荷瘤鼠皮下建立U251移植瘤实验模型的方法简便、潜伏期短、成功率高、稳定性好，可以作为胶质瘤体内实验研究的动物模型。     

P16基因与脑胶质瘤

P16/CDKN2基因又称多肿瘤抑制基因,它编码一种细胞周期素依赣性激酶C(Cdk_4)抑制蛋白,能特异地抑制Cdk_4活性,阻止细胞从G_1期进入S期,抑制细胞增殖。P16基因变异会导致细胞无控制地生长。P16基因变异包括缺失、突变和甲基化。许多实验证实P16基因变异与脑胶质瘤的进展有关。     

溶瘤病毒治疗恶性胶质瘤的研究进展

胶质瘤是最常见的颅内肿瘤,尤其是恶性胶质瘤的死亡率和复发率极高,对人类危害极大。溶瘤病毒作为治疗肿瘤的新方法,利用自然界病毒或者经过基因改造过的病毒选择性地感染并且裂解肿瘤细胞,达到治疗肿瘤的目的。近年来溶瘤病毒已广泛用于治疗恶性胶质瘤的研究,但由于溶瘤病毒受自身条件限制,靶向性、安全性、溶瘤效力都存在一定局限性,所以越来越多的研究者开始把抗肿瘤基因和多种内源性抗肿瘤因子导入溶瘤病毒,增强溶瘤效力,并与传统放化疗相结合,取得了较好的效果。多种肿瘤治疗手段结合渐渐成为溶瘤病毒治疗肿瘤的发展趋势。本文主要探讨溶瘤病毒在对恶性脑胶质瘤治疗方面的研究进展以及未来的研究方向。     

NF2基因及其编码蛋白质结构的研究进展

Ⅱ型神经纤维瘤病（neurofibromatosisⅡ，NF2）是一种常见的常染色体显性遗传性疾病。其临床表现为以双侧听神经受累为主的多种类型的肿瘤，如视神经胶质瘤、脑膜瘤、星型细胞瘤、脊膜瘤以及室管膜细胞瘤等。非常具有特征性的是，NF2中枢神经系统肿瘤多发生于包被结构，如神经鞘瘤（施万细胞瘤）和脑膜瘤。[第一段]     

胶质瘤干细胞靶向治疗的新领域

<正>胶质瘤是颅内最常见的原发中枢神经系统肿瘤,其中多形性胶质母细胞瘤(glioblastoma multiforme,GBM)占胶质瘤总病例数的一半左右,中位生存期仅14.6个月[1]。胶质瘤干细胞(glioma stem cells,GSCs)是形成胶质瘤和启动肿瘤快速增殖的初始细胞,并具有完整的成瘤能力[2]。GSCs的主要标志物是细胞分化标志133(cluster of differentiation 133,CD133)。近几年还发现多种干     

世界卫生组织中枢神经系统肿瘤分类：神经肿瘤专业医师堪与之厮守终生的学问

正中枢神经系统肿瘤领域的知识体系庞大,理论与技术不断进步。中枢神经系统肿瘤的临床诊治更是个大学问。2019年第11和12期以及2020年第2期,我在《中国现代神经疾病杂志》主持了3期"脑胶质瘤"专题,内容主要涵盖我国脑胶质瘤临床诊断与治疗指南/规范建设、中枢神经系统肿瘤病理分类进展、脑胶质瘤临床试验创新体系及临床疗效反应评价体系、脑胶质瘤侵袭迁移及免疫治疗研究、     

人脑胶质瘤PTEN基因变异的研究

目的进一步了解PTEN基因突变和缺失在人脑胶质瘤发生和恶性进展中的作用。方法应用聚合酶链反应-单链构象多态性(PCR-SSCP)结合银染技术和双重PCR分别检测10例正常脑组织、10例脑膜瘤、80例胶质瘤PTEN基因第5和第8外显子区域上的突变与缺失情况。结果发现10例正常脑组织和10例良性脑膜瘤均无PTEN基因点突变发生,80例胶质瘤分别有11例(13.75%)和27例(33.75%)发生基因点突变和基因缺失,且PTEN基因失活与星形细胞瘤病理分级明显相关(P<0.05),其中高恶性度胶质瘤(III、IV级)突变率(24.44%)和缺失率(60%)明显高于低恶性度(I、II级)胶质瘤(P<0.05)。结论PTEN基因突变或缺失与胶质瘤病理分级关系密切,可能属于胶质瘤恶性进展的后期事件。     

NF2 tumor suppressor gene: a comprehensive and efficient detection of somatic mutations by denaturing HPLC and microarray-CGH

The NF2 tumor suppressor gene, located in chromosome 22q12, is involved in the development of multiple tumors of the nervous system, either associated with neurofibromatosis 2 or sporadic ones, mainly schwannomas and meningiomas. In order to evaluate the role of the NF2 gene in sporadic central nervous system (CNS) tumors, we analyzed NF2 mutations in 26 specimens: 14 meningiomas, 4 schwannomas, 4 metastases, and 4 other histopathological types of neoplasms. Denaturing high performance liquid chromatography (denaturing HPLC) and comparative genomic hybridization on a DNA microarray (microarray- CGH) were used as scanning methods for small mutations and gross rearrangements respectively. Small mutations were identified in six out of seventeen meningiomas and schwannomas, one mutation was novel. Large deletions were detected in six meningiomas. All mutations were predicted to result in truncated protein or in the absence of a large protein domain. No NF2 mutations were found in other histopathological types of CNS tumors. These results provide additional evidence that mutations in the NF2 gene play an important role in the development of sporadic meningiomas and schwannomas. Denaturing HPLC analysis of small mutations and microarray-CGH of large deletions are complementary, fast, and efficient methods for the detection of mutations in tumor tissues.     

Homozygous deletions of the CDKN2/p16 gene in dural hemangiopericytomas

While most authors currently classify dural-based hemangiopericytoma (HPC) as a distinct entity rather than as a subtype of meningioma, the histogenesis of HPC has long been debated. We have recently shown that meningiomas contain frequent mutations of the neurofibromatosis 2 gene, while HPCs do not, suggesting that HPC is genetically distinct from meningioma. In the present study, we evaluated a series of 31 dural HPCs (including 3 pairs of primary and recurrent tumor) and 26 meningiomas for alterations in the cell-cycle regulatory genes CDKN2/p16 and p53. Homozygous deletions of the CDKN2/p16 gene were detected using a comparative multiplex polymerase chain reaction assay in 7 of 28 primary HPCs (25%), but in only one of 26 meningiomas (P = 0.03). Among the HPCs with recurrence, 1 pair of 3 had a homozygous CDKN2/p16 deletion. The 1 meningioma with a CDKN2/p16 deletion was a meningothelial meningioma, without atypical or malignant features. Single-strand conformational polymorphism analysis of all three exons of CDKN2/p16 and exons 5–8 of p53 revealed no mutations in either HPCs or meningiomas. These results illustrate that homozygous deletions of CDKN2/p16 occur in HPCs and suggest that alterations of the p16-mediated cell-cycle regulatory pathway may underlie the formation or progression of some HPCs. The data also provide further genetic evidence that HPC is not a subtype of meningioma. Received: 26 September 1995 / Revised, accepted: 30 October 1995     

Systemic metastasis in glioblastoma may represent the emergence of neoplastic subclones

Glioblastomas only rarely metastasize to sites outside the central nervous system, for reasons that are poorly understood. We report the clinicopathological and molecular genetic findings in 6 patients with metastatic glioblastoma. Four patients were under the age of 32 and all but 1 patient died within 2 yr of diagnosis. The number of metastases ranged from 1 to 3. At the time of death, 3 patients had apparent tumor control at their primary site. We evaluated DNA from both primary and metastatic glioblastomas for genetic alterations commonly found in glioblastomas: TP53 mutations, CDKN2A/p16 deletions, EGFR amplification, and allelic loss of chromosomes 1p, 10q and 19q. Four of 6 cases had TP53 mutations and only single cases had EGFR amplification, CDKN2A/p16 deletions, or allelic loss of 1p, 10q and 19q; 2 cases had no detectable genetic alterations. In 2 cases, the primary and metastatic tumors had identical genotypes. Remarkably, however, 2 cases had different TP53 alterations in the primary and metastatic lesions, or among the metastatic tumors, which suggests that some metastatic deposits may represent emergence of subclones that were not necessarily dominant in the primary tumor. The present observations and a review of the recent literature demonstrate that metastatic glioblastomas tend to occur in younger adults who do not follow long clinical courses, and may be characterized by TP53 mutations and differential clonal selection.     

BRAF Duplications and MAPK Pathway Activation Are Frequent in Gliomas of the Optic Nerve Proper

ABSTRACT: Optic pathway gliomas represent a specific subtype of astrocytoma with unique clinicopathologic and biologic properties, but studies of tumors in the optic nerve proper have been hampered by limited tissue availability. We analyzed optic nerve gliomas of 59 patients (median age, 9 years; range, 3 months-66 years; 33 female, 26 male) using formalin-fixed paraffin-embedded material in tissue microarrays. Seven patients had the clinical diagnosis of neurofibromatosis type 1 (NF1). Fluorescence in situ hybridization studies were performed for BRAF, PTEN, CDKN2A (p16), and NF1. Immunohistochemistry was performed for glial fibrillary acidic protein, phospho-ERK, and mutant IDH1 protein. The BRAF duplication was present in 11 (73%) of 15 evaluable tumors, including 1 NF1 patient (1 of 4 tested; 25%). The single tumor lacking BRAF duplication or NF1 association had histologic features of a ganglioglioma. Conversely, heterozygous PTEN deletions were present in 2 (8%) of 25 evaluable cases, one of which was BRAF duplicated and the other was NF1 associated. CDKN2A and NF1 deletions were absent in all tumors tested. Phospho-ERK immunoreactivity was present in 55 (96%) of 57 tumors and was mostly strong and diffuse (80%). Only 1 case of 53 expressed IDH1. Thus, optic nerve gliomas demonstrated molecular alterations typical of pilocytic astrocytomas, including the universal presence of either BRAF duplication or NF1 association and common mitogen-activated protein kinase pathway activation but very rare mutant IDH1 expression.     

脑胶质瘤中c—myc基因扩增,H—ras及p53基因突变

研究脑胶质瘤中癌基因c-myc的扩增、H-ras的突变及抑癌基因p53的5～8外显子的突变情况以及与胶质瘤的恶性程度的关系.采用差异性PCR(DPCR)及PCR-SSCP、PCR-RFLP等方法检测22例脑胶质瘤的基因突变情况.22例脑胶质瘤中c-myc扩增率为63.6%(14/22),H-ras的突变率为36.4%(8/22),p53的突变率45.5%(10/22).提示:癌基因c-myc的扩增及抑癌基因p53的突变与脑胶质瘤的恶性程度有关(P<0.05),而癌基因H-ras的突变则与脑胶质瘤的发生有关,与脑胶质瘤的恶性程度无关(P>0.05).各类型脑胶质瘤基因突变未发现不同(P>0.05),可能与标本量少有关.     

Expression of the neural RNA-binding protein Musashi1 in human gliomas

Tumor cells arising from a particular tissue may exhibit the same gene expression patterns as their precursor cells. To test this proposition, we have analyzed the expression of a neural RNA-binding protein, Musashi1, in primary human central nervous system (CNS) tumors. In rodents, Musashi1 is expressed predominantly in proliferating multipotent neural precursor cells, but not in newly generated postmitotic neurons. The expression of Musashi1 is downregulated with the successive progression of neurogenesis. In normal adult human tissues, we detected low levels of Musashi1 expression in brain and testis by RT-PCR analysis. In an RNA panel of 32 cancer tissues and cell lines, elevated expression of Musashi1 was seen in all five malignant gliomas studied, in contrast to the slight expression seen in other tumor cells, including those in several melanomas and a prostate cancer. Western blot analysis showed strong Musashi1 expression in malignant gliomas compared with nonneoplastic brain tissue. Glioblastomas, the most malignant form of glioma, showed higher Musashi1 expression than less malignant gliomas by immunohistochemical analysis. Tumors with strong Musashi1 expression tended to have high proliferative activity. Thus, the expression of Musashi1 correlated with the grade of the malignancy and proliferative activity in gliomas. These results suggest that primary CNS tumors may share gene expression patterns with primitive, undifferentiated CNS cells and that Musashi1 may be a useful marker for the diagnosis of CNS tumors.