应用微阵列初步研究少支胶质细胞瘤的基因表达谱

目的：应用微阵列研究少支胶质细胞瘤的基因表达谱。方法：从2例新鲜少支胶质细胞瘤及1份正常脑组织标本中提取总RNA，逆转录为^32P标记的cDNA、与Atlas微阵列杂交，洗膜、放射自显影，应用专用软件分析所得杂交图。结果：与正常脑组织相比，2例少支胶质细胞瘤共有63个基因表达上调，4个基因表达下调。2例肿瘤间基因表达量有显著差异。部分基因的表达趋与已知基因信息不同。结论：Atlas微阵列可高效显示少支胶质瘤的基因表达谱，并为进一步肿瘤分子发病机理提供新信息。     

脑胶质瘤相关新基因表达的微阵列基因芯片分析

目的用基因芯片技术获取人脑胶质瘤组织和人正常脑组织中差异表达的相关基因，并对部分基因在不同级别胶质瘤中的表达进行初步研究。方法用含有218个与人类神经系统发育相关基因的表达谱芯片，提取正常脑组织及胶质瘤组织总RNA制备探针并杂交芯片，用ScanArray4000扫描芯片，对其中差异表达基因进行生物信息学分析，并用实时定量PCR方法验证smad1、Hmp19和TRIP3的mRNA在不同级别胶质瘤中的表达改变。结果与正常脑组织相比，胶质瘤中明显差异表达基因10个，包括细胞周期相关基因、转录和细胞转导相关基因、增殖和分化相关基因。其中表达下调基因5个，表达上调基因5个，经实时定量PCR验证smad1、Hmp19和TRIP3的表达结果与芯片检测结果相符，且随胶质瘤恶性级别的不同而变化。结论胶质瘤发生发展中存在多类基因表达的改变，表达谱基因芯片技术能快速有效地反映肿瘤发展过程中的基因改变，为胶质瘤的侵袭性和预后判断提供依据以及为导向治疗和基因治疗提供更多的靶基因。     

髓母细胞瘤与幕上原始神经外胚叶肿瘤中RASSF1A基因的甲基化差异

目的通过研究髓母细胞瘤与幕上原始神经外胚叶肿瘤（SPNET）中RASSF1A基因的甲基化改变,探讨颅内原始神经外胚叶肿瘤（PNET）的不同亚型中该基因的表遗传学差异及其意义。方法收集25例原发髓母细胞瘤,9例原发SPNET,3株髓母细胞瘤细胞系和2株SPNET细胞系。采用甲基化特异性聚合酶链反应（MSP）检测RASSF1A基因启动子区的甲基化状态。应用去甲基化试剂5-aza-2’deoxycytidine处理存在基因表达缺失的细胞系,探讨基因表达与甲基化之间的关系。结果100％（25／25）的原发髓母细胞瘤、6／9的原发SPNET及全部PNET细胞系中均检测到RASSFIA基因的甲基化。相反,该基因甲基化在全部正常组织（包括2例小脑,5例大脑）中均未检测到。并且,RASSF1A在SPNET中的甲基化率明显低于髓母细胞瘤（Fisher精确检验,P=0．014）。在经去甲基化试剂处理的PNET细胞中,该基因表达得以恢复,证明甲基化与该基因沉默相关。结论RASSF1A甲基化是肿瘤特异性的,RASSF1A甲基化与PNET的发生有一定关联,不同亚型的PNET之间RASSF1A基因的不同甲基化状态提示髓母细胞瘤和SPNET是表遗传学上存在差异的两类肿瘤。     

髓母细胞瘤8号染色体短臂的杂合性丢失

目的研究髓母细胞瘤8号染色体的遗传学异常,寻找与该肿瘤发病机制有关的杂合性丢失位点。方法通过微卫星分析（microsatellite analysis）方法,应用19个位于8号染色体短臂（8p）上的多态性标记物,检测髓母细胞瘤的杂合性丢失（loss of heterozygosity,LOH）。结果在所检测的23例髓母细胞瘤中,21例为原发肿瘤,2例为复发肿瘤。染色体8p总的LOH比率为51%（124个LOH/243个可分析位点）。我们在8p22-23.2之间发现了一个高比率的共同丢失区,其长度为18.14 cM。结论染色体8p22-23.1上很可能存在重要的抑癌基因,该基因的丢失可能与髓母细胞瘤发病有关。     

免疫组织化学标记在儿童髓母细胞瘤分子分型中的应用及其临床意义

目的:探讨免疫组织化学标记在儿童髓母细胞瘤分子分型中应用的可行性,分析分子分型相关蛋白的表达与肿瘤临床病理特点及预后的关系.方法:应用组织芯片技术及免疫组织化学Elivision法检测β-catenin,Gli-1,NPR3及KCNA1在40例儿童髓母细胞瘤中的表达,分析根据表达结果行分子分型的可行性及蛋白表达与年龄、性别、肿瘤部位、病理分型及预后的关系.结果:40例肿瘤组织中β-catenin,Gli-1,NPR3及KCNA1的阳性率分别为10％,55％,50％及30％,Gli-1阳性表达与患儿年龄及病理类型相关(P＞0.05).Kaplan-Meier生存分析提示＜3岁年龄组及Gli-1阳性组患儿预后较差(P＜0.05).Cox比例风险回归分析显示患儿年龄、病理分型、Gli-1蛋白及NPR3蛋白表达是儿童髓母细胞瘤的独立预后因子(P＜0.05).22例髓母细胞瘤(medulloblastoma,MB)行分子分型,其中WNT型4例,SHH型10例,3型6例,4型2例,Kaplan-Meier生存分析提示分子分型与预后无关(P＜0.05).结论:p-catenin核阳或核浆阳可作为WNT型髓母细胞瘤的蛋白标志物,Gli-1表达与患儿年龄及病理学类型密切相关,阳性表达提示患儿预后较差,是独立的预后因子之一,但其表达与NPR3及KCNA1的表达有部分重叠,因此尚需结合SHH型、3型及4型髓母细胞瘤的其它分子检测方法进行准确的分子分型.     

上调microRNA-383对人髓母细胞瘤D341细胞系中PRDX3表达的影响

目的探讨microRNA-383(miR-383)对人髓母细胞瘤D341细胞系中PRDX3基因的表达及细胞增殖活性与凋亡等细胞功能学的影响。方法应用实时荧光定量PCR法检测人髓母细胞瘤D341细胞系、正常脑组织中miR-383及PRDX3 mRNA表达水平;采用Western blot法检测人髓母细胞瘤D341细胞系、正常脑组织中PRDX3基因、蛋白表达水平;人工合成miR-383模拟体(mimics)转染MBD341细胞系,采用cck-8法、流式细胞术等实验方法检测转染人髓母细胞瘤D341细胞系后各组D341细胞增殖与凋亡、细胞内活性氧水平、线粒体膜电位水平的变化。结果人髓母细胞瘤BD341细胞系中miR-383表达水平为正常脑组织的0.524倍,明显下调。而PRDX3基因mRNA表达水平为正常脑组织的5.214倍,蛋白表达水平较正常脑组织明显上调。miR-383 mimics转染D341细胞系24、48 h,实验组miR-383表达水平均明显高于空白对照组,且48 h作用更加明显;而PRDX3基因mRNA、蛋白表达水平48 h较空白对照组降低。cck-8法检测提示实验组中细胞增殖率降低(P<0.05)。An-nexinV-FITC法检测转染后24、48 h细胞凋亡结果显示miR-383 mimics实验组细胞早期凋亡率明显增高,且24 h作用较明显(P=0.000)。细胞内活性氧水平和线粒体膜电位水平检测结果分别显示,转染后24、48 h实验组较对照组细胞内活性氧水平明显升高,而线粒体膜电位水平较对照组明显降低。结论与正常脑组织相比,miR-383在人髓母细胞瘤D341细胞系中表达降低,PRDX3基因表达升高。上调miR-383可敲低D341细胞系中PRDX3基因表达,并可抑制D341细胞增殖活性,促进D341细胞凋亡,出现D341细胞内活性氧水平升高、线粒体膜电位水平降低的细胞功能学变化。     

Upregulation of microRNA-383 influences the PRDX3 expression on human medulloblastoma cell line D341

目的 探讨microRNA-383(miR-383)对人髓母细胞瘤D341细胞系中PRDX3基因的表达及细胞增殖活性与凋亡等细胞功能学的影响.方法 应用实时荧光定量PCR法检测人髓母细胞瘤D341细胞系、正常脑组织中miR-383及PRDX3 mRNA表达水平;采用Western blot法检测人髓母细胞瘤D341细胞系、正常脑组织中PRDX3基因、蛋白表达水平;人工合成miR-383模拟体(mimics)转染MBD341细胞系,采用cck-8法、流式细胞术等实验方法检测转染人髓母细胞瘤D341细胞系后各组D341细胞增殖与凋亡、细胞内活性氧水平、线粒体膜电位水平的变化.结果 人髓母细胞瘤BD341细胞系中miR-383表达水平为正常脑组织的0.524倍,明显下调.而PRDX3基因mRNA表达水平为正常脑组织的5.214倍,蛋白表达水平较正常脑组织明显上调.miR-383 mimics转染D341细胞系24、48 h,实验组miR-383表达水平均明显高于空白对照组,且48 h作用更加明显;而PRDX3基因mRNA、蛋白表达水平48 h较空白对照组降低.cck-8法检测提示实验组中细胞增殖率降低(P<0.05).AnnexinV-FITC法检测转染后24、48 h细胞凋亡结果显示miR-383 mimics实验组细胞早期凋亡率明显增高,且24 h作用较明显(P=0.000).细胞内活性氧水平和线粒体膜电位水平检测结果分别显示,转染后24、48 h实验组较对照组细胞内活性氧水平明显升高,而线粒体膜电位水平较对照组明显降低.结论 与正常脑组织相比,miR-383在人髓母细胞瘤D341细胞系中表达降低,PRDX3基因表达升高.上调miR-383可敲低D341细胞系中PRDX3基因表达,并可抑制D341细胞增殖活性,促进D341细胞凋亡,出现D341细胞内活性氧水平升高、线粒体膜电位水平降低的细胞功能学变化.     

髓母细胞瘤10号染色体的杂合性丢失分析

目的探讨髓母细胞瘤的遗传学异常及其发病机制。方法通过微卫星分析（microsatellite analysis）方法,应用7个分别位于10号染色体长臂上PTEN（10q23）和DMBT1（10q25）基因位点的特异性标记物,分析18例髓母细胞瘤的杂合性丢失（loss of heterozygosity,LOH）。结果18例髓母细胞瘤中,位于10q23上的LOH比率为24％（9／37可分析标记）;位于10q25上的LOH比率为47％（9／19可分析标记）。结论在髓母细胞瘤中,染色体10q25上高比率的杂合性丢失提示,位于该位点上DMBT1基因的遗传学改变可能在髓母细胞瘤的发病机制中起着重要的作用。     

Notch1和Notch2在星形细胞瘤及髓母细胞瘤中的表达及其意义

目的 探讨Notch1和Notch2在人脑星形细胞瘤及髓母细胞瘤中的表达及其在肿瘤形成和发展中的作用.方法 应用组织芯片和免疫组织化学SP法染色以及Western blot技术检测正常脑组织、不同级别大脑星形细胞瘤、小脑髓母细胞瘤中Notch1和Notch2蛋白的表达情况.结果 正常脑组织中Notch1和Notch2蛋白呈阴性表达;Notch1在Ⅳ级星形细胞瘤中阳性比为15/15,Ⅲ级中阳性比为14/15,Ⅱ级中阳性比为10/15,Ⅰ级中阳性比为9/15,总阳性率为80.0%(48/60),阳性部位均为胞质.Ⅰ、Ⅱ、Ⅲ、Ⅳ级星形细胞瘤中表达阳性比及表达强度随肿瘤级别增高而增高.在髓母细胞瘤中阳性比为2/10,且表达水平较低.Notch2在Ⅳ级星形细胞瘤中无表达(0/15),Ⅲ级表达阳性比为1/15,Ⅱ级中阳性比为2/15,Ⅰ级中阳性比为3/15,总阳性率为10%(6/60),表达率及表达强度都很低.在髓母细胞瘤中阳性比为9/10.Notch1在各级别胶质瘤中表达强度的差异均有统计学意义(x2=18.495,P<0.05).Spearman等级相关检验证实肿瘤病理分级与Notch1表达强度之间呈正相关(r=0.859,P<0.05).在星形细胞瘤中,Notch1和Notch2表达的总阳性率差异有统计学意义(x2=56.807,P<0.05),在髓母细胞瘤中,Notch1和Notch2的表达差别有统计学意义(x2=13.778,P<0.05).结论 Notch1和Notch2在星形细胞瘤及髓母细胞瘤中表达不同,并呈现相反的趋势,可能与两者在脑发育过程中的作用不同有关.     

通过DNA甲基化测序来破译髓母细胞瘤的基因序列

表观遗传学的改变,DNA甲基化和核染色质结构的破坏,目前被认为是肿瘤发生过程中最普遍的的特征。这种现象也毫无例外的发生在儿童脑的髓母细胞瘤中。尽管从目前基因组学的研究中,对髓母细胞瘤取得较大的进展,然而四种不同分子亚型(WNT、SHH、Group 3及Group 3)间均存在许多不同的特点,许多案例仍缺乏明显的基因启动子。作者对34个人类和5个鼠类动物的髓母细胞瘤,加上8个人类和3个鼠类正常对照组进行深入分析,包括对整个基因组     

肺腺癌同源正常组织中差异表达基因的克隆

目的 从与肺腺癌同源的正常组织中筛选差异表达基因，以期从分子水平阐明机体抑制肿瘤发生的机制。方法 利用抑制性消减杂交分别肺癌组织及肺腺癌同源正常组织cDNA片段，并建立相应的cDNA文库。用肺腺癌组织及与其同源的正常组织cDNA片段作为探针，分别进行逆向和正向斑点杂交，筛选与同源正常组织探针杂交而不与肺腺癌组织探针杂交的阳性克隆并测序，测序结果与GenBank中的序列进行同源性分析。结果 在肺腺癌同源正常组织中，获得12个差异表达基因片段，其中4个与细胞凋亡相关基因有较高的同源性；8个与人类不同染色体的不同区域有较高的同源性，功能不详。结论 推测肺腺癌同源正常组织中存在凋亡相关基因等，它们可能通过多种途径促进细胞凋亡而抑制细胞异常增殖，从而达到抑制肿瘤发生的目的。     

High-throughput tissue microarray analysis to evaluate genes uncovered by cDNA microarray screening in renal cell carcinoma

Many genes and signaling pathways are involved in renal cell carcinoma (RCC) development. However, genetic tumor markers have not gained use in RCC diagnostics and prognosis prediction. Identification and evaluation of new molecular parameters are of utmost importance in cancer research and cancer treatment. Here we present a novel approach to rapidly identify clinically relevant molecular changes in cancer. To identify genes with relevance to RCC, a cDNA array analysis was first performed on 5184 cDNA clones on a filter to screen for genes with differential expression between the renal cancer cell line CRL-1933 and normal kidney tissue. There were 89 differentially expressed genes in the cancer cell line, one of them coding for vimentin, a cytoplasmic intermediate filament. In a second step, a renal cancer tissue microarray containing 532 RCC specimen was used to determine vimentin expression by immunohistochemistry. Vimentin expression was seen frequently in clear cell (51%) and papillary RCC (61%), but rarely in chromophobe RCC (4%) and oncocytomas (12%). Furthermore, vimentin expression was significantly associated with poor patient prognosis (P < 0.007) independent of grade and stage. These results obtained from minute arrayed tumor samples match well with previous findings on vimentin expression in renal tumors. It is concluded that the combination of tumor arrays and cDNA arrays is a powerful approach to rapidly identify and further evaluate genes that play a role in tumor biology.     

食管癌及癌旁组织中基因表达的初步研究

目的　了解食管癌的基因表达概况,寻找在食管癌及癌旁组织中差异表达基因。方法　以癌及癌旁组织ｐｏｌｙ Ａ＋ Ｒ Ｎ Ａ 反转录合成的ｃ Ｄ Ｎ Ａ 为探针,与 Ａｔｌａｓ 微点阵表达分析膜进行差异杂交。结果放射自显影结果显示在所分析的５８８ 种已知基因中,ｃｄｃ２５ Ｂ、 Ｍ Ｍ Ｐ、 Ｍ Ｅ Ｔ 等６１ 个在食管癌组织中表达上调,ｃｙｔｏｋｅｒａｔｉｎ ４ 、 Ｂ Ａ Ｄ、 Ｉ Ｌ１ Ｒ Ｅ Ｃ Ｅ Ｐ Ｔ Ｏ Ｒ Ａ Ｎ Ｔ Ａ Ｇ Ｏ Ｎ Ｉ Ｓ Ｔ、 Ｉ Ｌ６ 等２２ 个表达下调,参与细胞增殖、凋亡、分化和转移调控的多种基因的表达水平发生了明显改变。结论　这些基因的表达改变组成了一个食管癌特异的基因表达谱,首次为食管癌细胞的恶性表型提供了分子遗传学参考数据,一些与肿瘤发生相关的差异表达基因为发展生物标记物或肿瘤早期诊断和治疗提供了线索。 Ａｔｌａｓ 微点阵表达分析滤膜的差异杂交为初步了解某一组织或细胞的表达状况提供了一个较好的方法。     

Genetic and expression profiles of cerebellar liponeurocytomas

Cerebellar liponeurocytoma, a rare, newly identified CNS neoplasm of adults, is characterized by advanced neuronal/neurocytic and focal lipomatous differentiation, low proliferative potential and a favorable clinical prognosis. Despite the different age distribution and benign biological behavior, the cerebellar liponeurocytoma shares several features with the cerebellar medulloblastoma, which may include an origin from the periventricular matrix of the fourth ventricle or the external granular layer of the cerebellum. To establish the genetic profile of cerebellar liponeurocytomas, we have formed an international consortium and collected tumor samples from 20 patients. DNA sequencing revealed TP53 missense mutations in 4 (20%) of 20 cerebellar liponeurocytomas, a frequency higher than in medulloblastomas. There was no case with PTCH, APC, or beta-catenin mutations, each of which may be present in subsets of medulloblastomas. Isochromosome 17q, a genetic hallmark of classic medulloblastomas, was not observed in any of the cases investigated by FISH analysis. cDNA array analyses were carried out on 4 cerebellar liponeurocytomas, 4 central neurocytomas, and 4 classic medulloblastomas. Cluster analysis of the cDNA expression data of 1176 genes grouped cerebellar liponeurocytomas close to central neurocytomas, but distinct from medulloblastomas. These results suggest cerebellar liponeurocytoma as a distinct tumor entity that is genetically different from medulloblastoma. Furthermore, the cDNA expression array data suggest a relationship to central neurocytomas, but the presence of TP53 mutations, which are absent in central neurocytomas, suggests that their genetic pathways are different.     

Expression of Matrix Metalloproteinases and Their Tissue Inhibitors in Human Brain Tumors

In this study, we investigated the expression patterns of 15 matrix metalloproteinases (MMPs) and three tissue inhibitors of metalloproteinase in gliomas, medulloblastomas, and normal brain tissue. By Northern blot analysis we found increased levels of mRNAs encoding for gelatinase A, gelatinase B, two membrane-type MMPs (mt1- and mt2-MMP), and tissue inhibitors of metalloproteinase-1 in glioblastomas and medulloblastomas. We observed a significant increase of mt1-MMP, gelatinase A, gelatinase B, and tissue inhibitors of metalloproteinase-1 in glioblastomas as compared with low-grade astrocytomas, anaplastic astrocytomas, and normal brain. In medulloblastomas, the expression of mt1-MMP, mt2-MMP, and gelatinase A were also increased, but to a lesser extent than that observed in glioblastomas. These data were confirmed at the protein level by immunostaining analysis. Moreover, substrate gel electrophoresis showed that the activated forms of gelatinases A and B were present in glioblastomas and medulloblastomas. These results suggest that increased expression of mt1-MMP/gelatinase A is closely related to the malignant progression observed in gliomas. Furthermore, the present study demonstrates, to our knowledge for the first time, that medulloblastomas express high levels of MMP.     

Radiation induces different changes in expression profiles of normal rectal tissue compared with rectal carcinoma

Purpose Radiotherapy is a very effective adjuvant treatment for rectal cancer with little side effects. Its killing effect on tumor cells seems to be more profound than the effect on normal tissue. The molecular events caused by irradiation are mainly analyzed in in vitro and animal models; investigations on human material are rare. In the current study, we analyzed the effects of irradiation on gene expression in normal and tumor tissue of rectal cancer patients.Methods and materials Normal and carcinoma tissue of patients from a randomized clinical trial of the benefits of preoperative radiotherapy were analyzed using the Affymetrix Human Cancer Gene Chip. Preoperative radiotherapy was given within 5 days prior to surgery. Results for normal tissue and tumor were compared to investigate the radiation-related differences between normal and tumor cells. We clustered the differentially expressed genes based on their functional annotation. Results were compared with immunohistochemical and literature data.Results The majority of the investigated cancer-related genes remained unchanged by irradiation (92% in tumor tissue and 93% in normal tissue). The differentially expressed genes varied between tumor and normal tissue except for maspin and IL-8. Both in tumor and normal tissue, differentially expressed genes were present related to cell signaling and cycle control, apoptosis and cell survival and tissue response and repair. However, the spectrum of affected genes was totally different.Conclusion Pre-existing differences in gene expression between normal tissue and tumor tissue might explain the differences in their responses to radiation. This change in response may explain the clinical beneficial effect of radiotherapy on tumor cells (low local recurrence rate) and the less severe effects on normal tissue (minor side effects).     

遗传性P77PMC癫痫大鼠海马基因表达谱的研究

目的利用cDNA表达阵列构建遗传性癫痫大鼠海马基因表达谱,寻找其中的差异表达基因,为从分子水平探讨癫痫的发病机理打下基础。方法采用32P-α-dATP逆转录标记探针与cDNA阵列杂交,构建P77PMC大鼠和Wistar大鼠海马基因表达谱,用图象分析仪分析两者基因表达谱差异。结果在P77PMC大鼠海马中共发现有15个差异表达基因,其中12个基因表达上调,3个基因表达下调。并用逆转录-聚合酶链反应进一步证实了结果的可靠性。结论P77PMC大鼠与正常Wistar大鼠海马中存在多个差异表达基因,这些差异表达的基因可能在癫痫的发生中具有重要作用。     

SLE及IDDM患者外周血单个核细胞中基因表达差异的研究

目的 :了解系统性红斑狼疮 (Systemiclupuserythematosus,SLE)和胰岛素依赖型糖尿病 (insulindependentdiabetesmellitusdisease,IDDM)外周血单个核细胞 (PBMC)的基因表达概况 ,为探讨这些基因表达的差异与该 2种疾病的关系奠定基础。方法 :以分别来自SLE和IDDM患者的PBMCpolyA RNA为模板逆转录合成cDNA表达探针 ,与AtlascDNA表达阵列膜进行差异杂交。结果 :放射自显影结果显示在SLE疾病所分析的 1176种已知基因中 ,有表达差异的 376个 ,其中表达上调差异率大于 3的 8个 ,表达下调差异率大于 6的 6个 ;在IDDM疾病所分析的 1176种已知基因中 ,有表达差异的 5 5 8个 ,其中表达上调差异率大于 6的 13个 ,表达下调差异率大于 6的 3个。与细胞的分化增殖、粘附与信号转导、凋亡、转录与调控及DNA损伤修复等相关的基因表达水平发生了明显的改变。结论 :AtlascDNA表达阵列差异杂交分析为初步了解SLE及IDDN患者PBMC的基因表达概况 ,进而了解基因表达差异在疾病发生发展中的作用提供了一个较好的方法。     

Interphase fluorescence in situ hybridization and DNA flow cytometry analysis of medulloblastomas with a normal karyotype

Interphase fluorescence in situ hybridization (FISH) with chromosome 3 and 17 centromeric probes and DNA flow cytometry were used for a retrospective study of nine pediatric medulloblastomas with normal karyotypes after tissue culture. The FISH analysis of medulloblastoma touch preparations showed that in seven of nine tumors, a significant proportion of nuclei had an increased number of centromeric signals for the selected chromosomes. In six of seven cases, this increase was caused by the presence of triploid and tetraploid clones as established by flow cytometry of paraffin-embedded tumors. These findings show that molecular cytogenetic analysis combined with DNA flow cytometry is necessary for all pediatric medulloblastomas diagnosed as cytogenetically normal on cultured tumor tissue.