脑胶质瘤相关的全长新基因PPIL-3的克隆和蛋白质特性的研究

目的 运用基因芯片技术获取正常成人脑组织与人脑胶质瘤中差异表达的基因,并对其中一条与脑胶质瘤相关的新基因进行了克隆和表达的研究.方法 抽提正常成人脑组织与人脑胶质瘤组织中的mRNA来制备探针,经杂交、洗涤后,通过计算机观察二者表达谱的差异情况,对681F05克隆子进行了Northern blot,生物信息学分析和蛋白质的表达.结果 通过4次基因芯片筛选,获得15条与胶质瘤相关的新基因,经Northern blot证实681F05基因在人正常脑组织中低表达,而在人脑胶质瘤中高表达.BLASTn和BLASTx分析显示,它们编码蛋白与线虫Cyp-10蛋白同源性分别为52%和72%.cDNA序列分析发现这两个克隆是同一个基因(cyclophilin-like gene,PPIL3)的两个不同的剪切体(PPIL3a和PPIL3b).并在大肠杆菌中得到了PPIL3a和PPIL3b与GST较好表达的融合蛋白.PPIL3b蛋白具有依赖于Ca2+/Mg2+核酸酶活性,其核酸酶活性可被一定浓度的K+/Na+抑制.结论 基因芯片筛选正常脑组织与人脑胶质瘤差异表达的基因具有样品用量少、高质量、高速度、高敏感等特性.681F05基因可能是与人脑胶质瘤形成有关的一条全长新基因.     

采用基因芯片技术获取人脑胶质瘤差异表达的基因及一条全长新基因的研究

目的：运用基因芯片技术获取正常成人脑组织与人脑胶质瘤中差异表达的基因,并对其中一条基因进行了初步的研究。方法：抽提正常成人脑组织与人脑胶质瘤组织中的mRNA来制备探针,经杂交、洗涤后,通过计算机二者表达谱的差异情况,对436F11克隆子进行了northern blot,原位杂交和生物信息学分析。结果：通过四次基因芯片筛选,获得15条与胶质瘤相关的新基因,经northern blot证实436F11基因在人正常脑组织中高表达,而在人脑胶质瘤中低表达。原位杂交得到相同的结果。BLASTn和BLASTx分析显示,436F11基因为全长新基因,其编码78个氨基酸,其理论分子量为8648Da,等电点为4．69,与鼠PKIβ69%同源,命名为人PKIβ。结论：基因芯片筛选正常脑组织与人脑胶质瘤差异表达的基因具有样品用量少、高质量、高速度、高敏感等特性。人PKIβ可能是与人脑胶质瘤形成有关的一条全长新基因,这为脑胶质瘤的基因治疗提供了一条新思路。     

人脑胶质瘤相关的二条全长新基因报导及染色体定位

目的 报导与人脑胶质瘤相关的二条新基因及其在染色体上的定位。方法 对发现的脑胶质瘤相关的二条新基因进行测序，Northern blot和序列局部对比查询（BLAST）分析，同时运用染色体辐射杂交（RH）技术对其进行染色体定位。结果 这二条新基因都是全长新基因，基因库登录号分别为AF225513和AF329277。经Northern blot证实436F11基因在人正常脑组织中高表达,而在人脑胶质瘤中低表达，而另一条基因507 E08则相反。RH染色体定位显示436F11基因在6q21-q23的D6S304和D62S2156 Marker之间，507E08基因在D14S1066Marker和D14S265 Marker之间。结论 找到了二条与人脑胶质瘤相关的全长新基因及其在染色体上的相应定位，这为胶质瘤的基因治疗提供了新思路。     

胶质母细胞瘤基因表达谱及相关基因的聚类研究

目的探讨人脑胶质母细胞瘤发生、发展中相关基因的表达及功能.方法用含13 939种人类基因的BioStarH140S型表达谱芯片,以正常成人脑及不同级别胶质瘤组织总RNA制备的探针杂交芯片;ScanArray 4000扫描芯片荧光信号,提取脑及胶质瘤组织差异基因并进行生物信息分析;用Hierarchical聚类对胶质瘤差异基因进行特征提取;用Northern杂交验证及进行初步功能研究.结果正常脑与18例不同级别胶质瘤组织间筛选出多类差异表达基因,通过生物信息学和Hierarchical聚类,发现α-连环素、微型染色体维护蛋白7、细胞周期素B2、FBX05、着丝粒蛋白F基因与胶质母细胞瘤密切相关,该类基因在低级别胶质瘤中表达差异不明显,但胶质母细胞瘤中表达明显上调.Northern杂交显示该类基因与胶质母细胞瘤密切相关,与芯片结果一致.结论基因表达谱芯片可快速、高效地筛选胶质瘤相关基因,发现的5条基因与胶质母细胞瘤侵袭性强密切相关,可成为判断胶质瘤预后的分子生物学指标.     

miR-92b对神经胶质瘤细胞U251增殖及迁移侵袭的 影响

目的 探究miR-92b对神经胶质瘤细胞U251增殖及迁移侵袭的影响以及其可能机制.方法 利用miRNA芯片筛选出在神经胶质瘤细胞U251和人脑正常胶质细胞HEB中差异表达的miRNA;化学合成法制备miR-92b抑制剂,转染后用real-time PCR技术验证表达变化;CCK-8实验检测转染后细胞的增殖能力;划痕实验和Transewll实验检测转染后细胞的迁移和侵袭能力;Western blot检测细胞中胰岛素样生长因子结合蛋白3(IGFBP-3)、β-catenin和E-cadherin的表达;荧光酶素实验验证IGFBP-3是否为miR-92b的靶基因.结果 基因芯片结果显示miR-92b在神经胶质瘤细胞中表达水平高于人脑正常胶质细胞(P<0.05);CCK-8实验结果显示转染miR-92b抑制剂后,U251细胞增殖能力降低(P<0.05);划痕实验和Transwell实验结果显示转染miR-92b抑制剂后,U251细胞迁移和侵袭能力降低(P<0.05);Western blot结果显示抑制miR-92b后,IGFBP-3和E-cadherin蛋白表达增加(P<0.05),β-catenin表达减少(P<0.05);荧光素酶实验结果显示,miR-92b能直接靶向调控IGFBP-3.结论 miR-92b在神经胶质瘤中表达显著增加,其可能通过抑制IGFBP-3蛋白表达,从而促进肿瘤细胞的增殖及迁移侵袭.     

Stathmin／Oncoprotein18（Op18）在人脑胶质瘤中的表达研究

目的探讨Stathmin／oneoprotein18（Op18）基因在人脑胶质瘤中的表达规律及意义。方法分别采用免疫组化法和Westernblot法检测10例正常脑组织和56例脑胶质瘤中Stathmin蛋白的表达。结果免疫组化法检测Stathmin蛋白在正常脑组织、低级别胶质瘤（Ⅰ～Ⅱ级）及高级别胶质瘤（Ⅲ～Ⅳ级）中阳性表达率分别为20％、65％、100％。正常脑组织分别与Ⅰ～Ⅱ级组、Ⅲ～Ⅳ级组比较，均有显著性差异（P〈0．05）；Ⅰ～Ⅱ级组与Ⅲ～Ⅳ级组比较，有显著性差异（P〈0．05）。Westernblot法检测显示，Stathmin蛋白在胶质瘤中的表达明显增高，正常脑组织分别与Ⅰ～Ⅱ级组、Ⅲ～Ⅳ级组比较，差异均有显著性（P〈0．01），Ⅰ～Ⅱ级组与Ⅲ～Ⅳ级组比较，差异有显著性（P〈0．01）。结论Stathmin在脑胶质瘤中过表达，Stathmin可能为脑胶质瘤的生物治疗提供一个新靶点。     

人BTBD10新基因克隆及组织表达和在脑胶质瘤中的表达谱及聚类

目的探讨人脑胶质瘤相关BTBD10新基因克隆、正常成人组织分布及在不同级别星形细胞瘤中的表达。方法构建胎脑cDNA文库和大规模测序获得全长BTBD10新基因;用Clontech人多组织文库(MTC)为模板研究BTBD10在8种正常组织中的分布;用含13 939种人类基因(8 347种已知基因,5 592种未知基因)的BioStarH140S型表达谱芯片检测BTBD10在星形细胞瘤中的表达,Hierarchical聚类分析与BTBD10表达谱相近的基因群;Northern杂交验证BTBD10在不同级别胶质瘤中的表达。结果人胎脑文库中克隆的BTBD10新基因含1 428bp长的开放阅读框,编码475个氨基酸的蛋白;芯片结果提示BTBD10基因在18例胶质瘤组织中表达一致降低,与促性腺诱导素转录阻抑蛋白GIOT1、血管性肠肽VIP等7条基因的表达谱相似;BTBD10在正常脑组织中表达量最高,而心、肺、肝、肾、胰腺中表达较低;Northern显示BTBD10与胶质瘤发生密切相关,与芯片结果一致。结论表达谱芯片可快速高效筛选脑胶质瘤相关基因,BTBD10基因与胶质瘤发生密切相关,在脑胶质瘤的转录调控中起重要作用。     

基因芯片在人脑星型细胞瘤基因研究中的初步应用

目的:探索基因芯片在人脑胶质瘤基因表达研究中的应用。方法:通过ＲＴ－ＰＣＲ反转录、同位素标记、基因芯片方法研究５例星型胶质瘤和４例正常脑组织ｍＲＮＡ的表达差异。结果:在 １４ ８９２个可表达顺序片断(ｅｘｐｒｅｓｓｉｏｎｓｅｑｕｅｎｃｅｔａｇ,ＥＳＴ)中,对照与２个胶质瘤样品间有１０２个差异表达。对照与３级样品间共有３９个显著差异表达基因,与４级样品间共有７８个显著差异表达基因,３级和４级肿瘤有５个共同异常表达基因。结论:基因芯片发现了胶质瘤的异常基因表达谱。     

肿瘤侵袭相关基因EMP3、PCDH-γ-A11在脑胶质瘤中的表达研究

目的探讨肿瘤侵袭相关基因EMP3和PCDH-γ-A11的mRNA在原发人脑胶质瘤组织中的表达情况，分析其表达变化与胶质瘤恶性程度的关系。方法分别应用传统的RT-PCR和SYBR Green实时定量PCR检测方法检测EMP3和PCDH-γ-A11基因mRNA在30例原发胶质瘤（WHO分级：Ⅱ级10例，Ⅲ级10例，Ⅳ级10例）和10例正常脑组织中的表达情况。统计学分析两个基因在胶质瘤和正常脑组织间的表达差异，并进一步结合临床资料分析不同分级、不同性别和不同年龄组间的表达差异。结果在各级别胶质瘤中EMP3和PCDH-γ—A11的mRNA与正常脑组织相比均表达下调，并具有显著意义（P〈0．01）；EMP3在Ⅱ级和Ⅳ级及Ⅲ级和Ⅳ级胶质瘤间的表达也存在统计学差异（P〈0．05）；PCDH-γ—A11在Ⅱ、Ⅲ和Ⅳ级胶质瘤相互之间的表达无统计学差异（P〉0．05）。结论各级别胶质瘤中EMP3和PCDH-γ—A11的mRNA表达均显著低于正常脑组织，并随胶质瘤恶性程度的增加表达量逐渐降低。EMP3基因的表达下调与胶质瘤的恶性程度密切相关。     

应用差异显示技术克隆胶质瘤细胞诱导分化相关基因

目的 克隆胶质瘤细胞诱导分化相关新基因。方法 应用RNA随机引物差异显示，SSCP纯化，PCR产物快速克隆，反Northern杂交及生物信息学分析等方法，观察人脑胶质瘤细胞株SHG－44－9分化过程中的基因表达变化。结果 克隆了诱导分化前后表达差异显著的15个基因，其中诱导后下调基因4个，上调基因11个。同源性分析表明，5个是已知基因，10个是未知基因。诱导后上调的DIG－1基因与c-myc内含子结合蛋白1（MIBP1）基因高度同源，此基因具有转录因子活性，表达的蛋白可抑制c-myc基因的表达。结论 克隆了15个人脑胶质瘤细胞诱导分化相关基因，其中控制c-myc基因表达的MIBP1基因诱导分化后上调提示，它可能是调控胶质瘤细胞分化基因，值得进一步研究。     

星形细胞瘤的基因表达谱和Hierarckcal聚类研究

目的 探讨人脑星形细胞瘤发生发展中相关基因及分类特征基因的表达。方法 用含13939种人基因的BioStarH140S芯片，以正常脑及18例胶质瘤组织总RNA制备的探针杂交芯片，ScanArray4000扫描信号，提取脑及不同级别星形细胞瘤的差异基因并行生物信息分析，Hierarchical聚类提取差异基因的特征。结果 星形细胞瘤中筛选出438条(3．14％)差异表达基因；信息分析与细胞信号、细胞骨架和运动、癌基因及抑癌基因等多类基因密切相关；与分类相关的特征基因有MAP7、DBCCR1、PCDHA5、KCNAB1、NAPIL2等。表达谱将星形细胞瘤分成两类，与临床组织病理分类基本一致。结论 芯片是基因分析和筛选肿瘤标志性基因的有效手段，可客观分析星形细胞瘤发展及预后；分类特征基因为星形细胞瘤侵袭性和预后判断提供依据，有助于临床诊治。     

Identification of two novel diurnal genes by screening of a rat brain cDNA library.

While the hypothalamus is fundamental for sleep and circadian regulation, the molecular mechanism involved are poorly understood. We have used a differential gene expression technique to identify hypothalamic genes which have altered expression in rat sleep periods. Complex cDNA probes from rat hypothalami removed at Zeitgeber times 4 and 15 were hybridised to rat brain cDNA library girds. From 30 differentially expressed clones, six were further analysed and two were confirmed to exhibit increased expression at Zeitgeber time 4. A Northern blot hybridization of brain, heart, kidney, lung, testis and skin mRNA showed that both clones were brain specific. Therefore, we have identified two novel brain specific diurnally expressed hypothalamic genes. Both genes may have roles in sleep or circadian regulation.     

Isolation and characterization of a library of cDNA clones that are preferentially expressed in the embryonic telencephalon.

In order to isolate genes involved in development of the mammalian telencephalon we employed an efficient cDNA library procedure. By subtracting an adult mouse telencephalic cDNA library from an embryonic day 15 (E15) mouse telencephalic cDNA library we generated two subtracted libraries (ES1 and ES2). We estimate that ES1 contains between 200 and 600 different cDNA clones, which approximates the number of genes that are preferentially expressed in the E15 telencephalon, compared to the adult telencephalon. Northern analysis of 20 different cDNA clones shows that 14 of these are expressed at least 5-fold more in the E15 telencephalon than the adult telencephalon. Limited sequencing of the 14 differentially expressed clones reveals that 10 have no significant identity to sequences in GenBank and EMBL databases, whereas the other 4 have significant sequence identity to vimentin, histone 3.3, topoisomerase I and the B2 repeat element. In situ hybridization using one of the differentially expressed cDNAs, TES-1, demonstrates that it is transiently expressed in the anlage of the basal ganglia. In situ hybridization with another differentially expressed cDNA clone, TES-4, shows that it is specifically expressed in differentiating cells of the neural axis with a distinctive rostral-caudal temporal pattern. These findings, and the methods that we have developed, provide a framework for future investigations of the genetic control of telencephalon development.     

Differential expression of glial fibrillary acidic protein in human glioma cell lines

Summary We have obtained a cDNA fragment to human glial fibrillary acidic protein (GFAP) by immunoscreening a gt11 human brain cDNA library with antibody to bovine GFAP. The highly homologous nucleotide sequence of this clone with that of the mouse GFAP enabled the identification of this cDNA as one encoding GFAP. As this cDNA hybridized with a single major RNA species in Northern blots of RNA from human and mouse brain tissues and gave one or two bands in Southern blots of human genomic DNA, it was considered to be specific for GFAP. Using this cDNA as a probe we investigated the levels of GFAP expression in ten human glioma cell lines. A 3.5-kb GFAP mRNA was detected in five of the ten glioma cell lines, one of which was U-251 MG cell line and the other four were clones derived from the same tumor (CL1, 2, 3, and 4). There was a difference in the amount of GFAP mRNA among U-251 MG and the four clonal cell lines. Quantitative evaluation of this difference by RNA dot blot analysis revealed that the amount of GFAP mRNA expressed in CL3 was about 1/5 and in CL4 about 1/10 the amount expressed in U-251 MG, CL1, and CL2. Semiquantitative Western blot analysis showed that GFAP levels corresponded to the GFAP mRNA levels in these cell lines. By Southern blot analysis of genomic DNA the GFAP gene was similarly detected in all of these cell lines regardless of the level of GFAP expression. Thus, by using a cDNa to human GFAP we have demonstrated the presence of clonal cell lines from human glioma showing different levels of GFAP expression, which may provide a useful basis for further investigations on the regulation of GFAP gene expression in glial cells.     

利用基因芯片研究与胶质母细胞瘤侵袭性相关的基因

目的探讨利用基因表达谱芯片筛选人脑胶质母细胞瘤与侵袭性相关基因的表达及功能。方法用含13 939种人类基因的BioStarH140S型芯片,以成人脑及6例胶质母细胞瘤组织总RNA制备的探针杂交芯片;ScanArray4 000扫描芯片荧光信号,提取脑及胶质母细胞瘤组织差异基因,并进行生物信息分析及功能研究。结果表达谱芯片筛选出胶质母细胞瘤差异基因198条(1.42％),与细胞信号和传递蛋白、细胞骨架、代谢、蛋白翻译合成、细胞周期蛋白类、癌基因和抑癌基因等多类基因密切相关;与侵袭性相关的8条细胞骨架和细胞外基质基因表达谱相似,均在胶质母细胞瘤中显著上调,生物信息分析为α-连环素基因、钙粘附素1基因、层粘连蛋白、纤连蛋白1基因、基质金属蛋白酶2、Ⅲ型胶原基因、组织金属蛋白酶抑制1基因和血小板衍生生长因子受体A基因。结论表达谱芯片是高通量筛选胶质瘤相关基因的生物高新技术,侵袭性相关基因为判断胶质母细胞瘤患者的预后提供了分子生物学指标,有助于临床诊治。     

Characterization of a novel mRNA expressed by neurons in mature brain.

In previous studies, differential hybridization screening of an activated murine T-lymphocyte cDNA library identified an interleukin 2-responsive mRNA, designated F5, expressed in lymphoid tissues and brain only. We now report characterization of a full-length clone isolated from an adult mouse brain cDNA library. Neither the nucleic acid nor amino acid sequences demonstrated similarity to reported sequences. On Southern blotting, the protein coding sequence hybridized to genomic DNA from a variety of species. On Northern blotting, F5 mRNA was expressed in adult mouse brain, spinal cord, eye, and dorsal root ganglia but not in peripheral nerve. In situ hybridization studies demonstrated prominent expression by neurons in brain. F5 mRNA expression was undetectable in embryonic rat cerebral hemisphere and low until postnatal day 21. F5 is a novel mRNA selectively expressed by proliferating lymphocytes and mature neurons.