神经母细胞瘤肿瘤细胞球富含表达Nestin细胞的研究

背景与目的:已有研究证实,悬浮生长的肿瘤细胞球具有自我更新和增殖的能力,同时表达干细胞的特征性标记物.本研究旨在通过分离、培养神经母细胞瘤获得肿瘤细胞球,观察其在体外的增殖、分化能力,并检测其表面特征性标志物.方法:取外科手术切除获得的神经母细胞瘤瘤块及骨髓转移患儿的骨髓标本,接种于含生长因子的无血清培养液中,悬浮培养;加入维甲酸(retinoic acid,RA)诱导细胞分化;接种裸鼠,比较肿瘤细胞球与非肿瘤细胞球裸鼠成瘤情况;利用免疫荧光及RT-PCR法比较肿瘤细胞球与非肿瘤细胞球细胞干细胞标志物Nestin表达的差异.结果:神经母细胞瘤细胞在无血清培养液中悬浮生长成肿瘤细胞球,传代后仍保持很强的自我更新和增殖能力;肿瘤细胞球在RA的诱导下分化,产生具有神经元形态特征的子代肿瘤细胞;1 ×104个肿瘤细胞球细胞14 d可形成移植瘤;RT-PCR及免疫荧光检测证实肿瘤细胞球表达神经干细胞的特异性标志物Nestin.结论:体外培养获得的神经母细胞瘤肿瘤细胞球中富集肿瘤干细胞;肿瘤细胞球中存在Nestin表达阳性的肿瘤干细胞.     

髓母细胞瘤中脑肿瘤干细胞的分离培养及鉴定

背景与目的:长期以来,脑肿瘤等实体肿瘤中是否存在肿瘤干细胞一直存在争论,最近已经有报道从胶质瘤和髓母细胞瘤等脑肿瘤及其它系统实体肿瘤中成功分离出肿瘤干细胞。本研究旨在利用简化的无血清培养基和悬浮培养方法,从人髓母细胞瘤中分离培养脑肿瘤干细胞,观察其在体外的增殖、分化,鉴定其特异性标志物CD133和Nestin的表达,验证肿瘤组织切片中CD133阳性细胞的存在,为脑肿瘤干细胞的进一步研究打下基础。方法:术中取11例患者髓母细胞瘤组织,分离成单细胞悬液,接种于含表皮生长因子、成纤维生长因子以及B27添加剂的无血清培养基中悬浮培养,以分离其中的脑肿瘤干细胞;对其增殖形成的脑肿瘤干细胞球连续传代培养;并进行单克隆形成实验,以确定原代肿瘤组织中肿瘤干细胞的百分率,观察脑肿瘤干细胞球的形成过程。然后,将脑肿瘤干细胞球接种于含血清培养基,观察脑肿瘤干细胞的分化现象。最后,利用免疫荧光法检测脑肿瘤干细胞特异性标志物CD133和Nestin在脑肿瘤干细胞球中的表达;利用免疫组化法检测组织切片中CD133阳性细胞的分布,并计算CD133阳性细胞百分率。结果:本组11例髓母细胞瘤中均仅有少数肿瘤细胞能够在无血清培养基中存活并悬浮生长、增殖形成克隆性脑肿瘤干细胞球,传代后脑肿瘤干细胞仍保持很强的自我更新和增殖能力。单克隆形成实验表明原代肿瘤细胞中具有单克隆形成能力的肿瘤干细胞百分率为(31.18±6.18)%。在含血清培养基中脑肿瘤干细胞发生贴壁分化,产生具有多种细胞形态的分化细胞。脑肿瘤干细胞表达神经干细胞的特异性标志物CD133和Nestin;肿瘤组织切片中CD133阳性细胞呈巢状或散在分布,占全部肿瘤细胞的(33.06±8.57)%。结论:人髓母细胞瘤组织中存在一定量的具有自我更新和增殖能力、表达CD133和Nestin的脑肿瘤干细胞,并能在体外将其分离、培养和诱导分化。     

应用长春新碱分离与鉴定U87细胞系中的胶质瘤干细胞

背景与目的:研究表明,肿瘤干细胞具有化疗抵抗性.本研究拟利用肿瘤干细胞对化疗药物耐受的特性,在培养基中添加长春新碱的方法从人胶质瘤细胞系U87中分离鉴定肿瘤干细胞.方法:U87细胞于含血清培养基中贴壁后,换用含有5 ng/ml长春新碱的神经干细胞培养基培养,获得第一代肿瘤细胞球后,将单细胞接种于神经干细胞培养基中,获得第二代肿瘤细胞球.免疫荧光检测巢蛋白(nestin)、胶质纤维酸性蛋白(glial fibrillary acidic protein,GFAP)、β-微管蛋白Ⅲ(β-tubulin Ⅲ)、髓鞘碱性蛋白(myelin basic protein,MBP)在第二代肿瘤细胞球及其分化细胞中的表达.结果:成功地获得了第一代肿瘤细胞球以及来源于单细胞的第二代肿瘤细胞球;细胞间紧密相贴,表面较光滑;神经干细胞标志物nestin在第二代肿瘤细胞球中呈阳性表达;第二代肿瘤细胞球分化细胞中可检测到nestin、GFAP、β-tubulin Ⅲ、MBP的表达.结论:U87细胞系中存在具有自我更新及多向分化能力的胶质瘤干细胞,采用神经干细胞培养基中添加长春新碱的方法能简单有效地从胶质瘤细胞系中分离培养出胶质瘤干细胞.     

miR-218对胶质母细胞瘤细胞成熟分化的影响

  目的  观察miR-218对胶质母细胞瘤细胞系成熟分化的影响。  方法  通过质粒转染和G418筛选建立稳定过表达miR-218的SNB-19亚细胞系及对照亚细胞系。利用qRT-PCR及Western blot检测稳定细胞系中miR-218、CD133及Nestin表达水平。用GFAP免疫细胞化学染色评价其成熟分化水平,通过免疫荧光观察转染miR-218表达质粒后CD133及Nestin阳性细胞的分布情况。  结果  过表达miR-218的亚细胞系中miR-218、CD133及Nestin表达水平分别是对照细胞的26.23倍、17.9%及54.2%,过表达miR-218细胞的GFAP阳性标记指数为（96.0±3.81）%显著高于对照细胞（49.6±5.13）%（t=16.24,P < 0.01）。免疫荧光显示CD133及Nestin的下调特异性发生于成功转染miR-218表达质粒的细胞。  结论  miR-218可通过促进胶质瘤干细胞的成熟分化显著下调CD133及Nestin的表达水平,该作用可能是miR-218抑制胶质瘤细胞增殖的重要机制之一。      

间变性节细胞胶质瘤复发为幕上原始神经外胚层肿瘤一例报告并文献复习

背景与目的：间变型节细胞胶质瘤非常少见,恶变总是发生在胶质成分。目前已有少量病例显示神经元成分的恶性转化。本文报道一例原发瘤为间变性节细胞胶质瘤,术后8个月复发为幕上原始神经外胚层肿瘤的病例。方法：观察并分析原发瘤和复发瘤的病理形态特征和免疫组化标记。结合文献讨论间变性节细胞胶质瘤转变为幕上原始神经外胚层肿瘤的可能机制。结果：患儿8岁。镜下见第一次切除的左颞叶肿瘤：部分区域肿瘤细胞密集分布。细胞较小,核染色较深,部分瘤细胞呈小片状,细胞稍大,核圆形或多角形,染色质淡。肿瘤组织中另可见散在或聚集向神经元分化的不同阶段的肿瘤细胞。细胞较大,有明显淡红染的胞浆,胞核空泡状,有核仁。有的似分化较成熟的节细胞。网状染色见瘤组织中纤维组织明显增生。免疫组化结果显示：GFAP灶性（＋）、NSE（＋）、S100（＋）、Nestin（＋）、VIM（＋）、Des（＋）。似神经元分化的大细胞则有NSE和S-100的阳性表达。病理诊断：伴有纤维增生的间变性节细胞胶质瘤。术后8个月左颞部复发肿瘤中除了仍见明显的纤维组织增生外,另见小或中等大小的肿瘤细胞密集排列,瘤细胞更异型,核分裂多见。未见较成熟分化的细胞。免疫组化显示：GFAP灶性（＋）、S100（＋）、NFP（＋）、Neuronal class III beta-tubulin（＋）。提示肿瘤细胞向神经元和胶质成分双向分化。病理诊断幕上原始神经外胚层肿瘤。结论：节细胞胶质瘤可以出现胶质和神经成分的恶性转化。     

免疫磁珠法分选人脑胶质瘤干细胞及其培养和鉴定

背景与目的:脑胶质瘤治疗效果一直不理想,这与胶质瘤细胞无限增殖能力和侵袭性生长有关,本研究旨在从人脑胶质瘤组织和细胞株中分离脑胶质瘤干细胞、进行体外培养并对其干细胞特性加以鉴定。方法:采用以CD133为标志的免疫磁珠法从人脑胶质瘤组织和细胞株中分离脑胶质瘤干细胞并进行体外培养,通过免疫荧光技术检测干细胞标志物CD133、Nestin,诱导分化后检查分化细胞标志物MAP2、GFAP、MBP以及电镜超微结构观察和移植SCID鼠致瘤实验,对其干细胞特性加以鉴定。结果:新鲜人脑胶质瘤组织和胶质瘤细胞株中存在一小部分CD133 的胶质瘤细胞,能表达干细胞的标志物CD133和Nestin,符合干细胞的超微结构特点,体外培养能连续传代;诱导分化后能产生MAP2、GFAP、MBP染色阳性的细胞;移植SCID鼠后能形成与亲本肿瘤表型一致的移植瘤。结论:新鲜人脑胶质瘤组织和胶质瘤细胞株中存在的一小部分CD133 胶质瘤细胞具有干细胞的属性,就是胶质瘤中的肿瘤干细胞,即胶质瘤干细胞。     

CD133~+胶质母细胞瘤细胞的分离与恶性行为特征

背景与目的:在恶性胶质瘤中存在一类恶性度极高的前体细胞,它们控制着肿瘤的生长与恶性演进,也是肿瘤复发的根源。本研究对胶质母细胞瘤进行肿瘤干细胞的分离与恶性行为特征分析,旨在验证胶质瘤干细胞的存在,并为未来该领域研究打下基础。方法:充分消化术中切除的胶质母细胞瘤组织块至单细胞悬液,流式细胞术检测CD133+肿瘤细胞百分率,免疫磁珠分选法分离CD133+和CD133-胶质母细胞瘤细胞;免疫荧光法检测两类细胞中巢蛋白(nestin)、胶质纤维酸性蛋白(GFAP)和神经元特异性烯醇化酶(NSE)的表达水平;Transwell双室培养体系检测两类瘤细胞的侵袭能力,血清依赖实验检测两类瘤细胞在低营养条件下的生存能力,软琼脂克隆形成实验检测瘤细胞的克隆形成能力;去胸腺小鼠腹股沟皮下接种瘤细胞,观察成瘤率。结果:流式细胞术检测CD133+肿瘤细胞百分率为(2.31±0.57)%。CD133+细胞高表达nestin,低表达GFAP和NSE;CD133-细胞则相反。与CD133-细胞比较,CD133+细胞具有更高的细胞侵袭能力、低营养耐受能力和克隆形成能力。CD133+细胞在小鼠体内成瘤率为87%(26/30),CD133-细胞为7%(2/30)。结论:CD133+胶质母细胞瘤细胞具有更高的恶性细胞表型,提示其具有高度研究价值。     

人恶性胶质瘤干细胞的分离与鉴定

目的:从人恶性胶质瘤中分离并鉴定胶质瘤干细胞。方法:采用神经干细胞无血清培养方法,分离胶质瘤干细胞,免疫细胞化学法、有限梯度稀释实验、二代球体形成分析、流式细胞分析等方法对胶质瘤干细胞进行鉴定。结果:3例患者原代培养胶质瘤细胞中CD133 细胞分别为7.4%、2.8%和4.2%。每100个原代胶质瘤细胞中可形成1个左右的胶质瘤细胞球;胶质瘤细胞球细胞均表达神经干细胞标记CD133和Nestin,不表达分化标志GFAP和MAP2,少数细胞表达分化标记MBP。每100个原代胶质瘤细胞球体细胞可形成6.07±2.15个悬浮生长的二代胶质瘤细胞球,二代细胞球细胞表达CD133和Nestin。胶质瘤细胞球细胞分化后细胞多数表达GFAP,少数表达MAP2和MBP。胶质瘤球体干细胞的增殖较原代胶质瘤细胞慢。胶质瘤球体细胞1×103个时可成瘤,原代培养的胶质瘤细胞需1×107。结论:采用神经干细胞培养条件可以很简便的分离出悬浮生长的胶质瘤球体干细胞。分离出的胶质瘤球体干细胞表达CD133抗原,具备肿瘤干细胞的基本特征。     

人脑胶质瘤干细胞SHG-44s的克隆及初步鉴定

目的:探讨人脑胶质瘤体外细胞系中存在肿瘤干细胞的可能性.方法:将SHG44细胞系和SHG44-9细胞株,分别应用含血清培养基(DMEM 10?S)和无血清培养基(DMEM/F12,添加bFGF、LIF和EGF)培养.用CD133免疫磁珠分离干细胞、Hoechst33342和NESTIN流式细胞仪、Nestin、NSE、GFAP免疫细胞化学染色检测肿瘤干细胞及其分化细胞.结果:CD133磁珠分离得到的干细胞的比例:在血清组SHG44和SHG44-9分别为0.021%和0.035%:无血清组分别为1.2%和2.3%.而Hoechst33342和CD133标记后流式细胞仪检测干细胞比例:血清组中SHG44、SHG44-9分别为1.5%、0.37%;无血清组分别为16.4%和29.1%.并且这些细胞能够增殖和分化成神经元和胶质细胞.而Nestin标记后SHG44、SHG44-9中分别有51.05%、77.53%阳性细胞.结论:体外长期传代培养的人脑胶质瘤细胞系中存在肿瘤干细胞SHG44s,CD133磁珠和Hoechst33342流式细胞仪分离和检测胶质瘤干细胞是行之有效的方法,而Nestin 细胞是干细胞分化后的祖细胞或前体细胞,不能作为分离和检测干细胞特异性标记物使用.     

胶质瘤干细胞的分离、培养及初步鉴定

目的:探讨人脑胶质瘤干细胞的培养和分离方法。方法:取9例脑胶质瘤患者的手术标本进行处理,采用B27培养基进行培养,碱性成纤维细胞生长因子和表皮生长因子刺激细胞扩增;应用免疫组织化学染色对培养的细胞及其分化的细胞进行鉴定。结果:9例标本中共有7例成功培养出肿瘤细胞球,培养条件下呈悬浮状态生长,形成肿瘤细胞球,免疫细胞化学检测显示肿瘤球细胞表达胶质瘤干细胞的标志物CD133和Nestin,诱导分化后的肿瘤球细胞可以表达成熟神经细胞的标志物GFAP和TU-20。结论:体外的培养条件下,可以从胶质瘤组织中培养出胶质瘤干细胞,为胶质瘤的深入研究奠定基础。     

Maintenance of retinal cancer stem cell-like properties through long-term serum-free culture from human retinoblastoma

Previous studies have demonstrated that a small population of cancer stem cell-like cells exists in retinoblastoma. To provide a model for studying this population, we sought to establish a long-term culture from human retinoblastoma that have cancer stem cell-like properties. Fresh tumor tissue was digested and cultured in serum-free medium. Tumor spheres formed and were passaged continuously. Stem cell properties were examined through immunostaining, real-time quantitative RT-PCR and chemoresistance assay. Tumorigenicity of the tumor sphere-forming cells was confirmed by xenograft experiments. Furthermore, we examined the expression of cell surface markers CD44 and CD133. Tumor cells expanded as floating spheres for more than 30 passages. Sphere-forming cells overexpressed stem cell genes Oct?4, Nestin and Pax6. Immunostaining of spheres showed positivity for Nestin, Pax6 and also ABCG2. In contrast, differentiated cells derived from these spheres expressed high levels of mature retinal cell markers MAP2, GFAP, recoverin, Opsin B and Nrl, and showed immunoreactivity for NF200, GFAP, recoverin and PKCα. Furthermore, both CD44 and CD133 were highly expressed in sphere-forming cells vs. differentiated cells. Sphere-forming cells displayed higher chemoresistance to carboplatin as opposed to differentiated cells. Moreover, intraocular injection of as few as 2x103 sphere-forming cells into NOD/SCID mice gave rise to new tumors similar to the original patient tumors. These results revealed that the sphere-forming cells preserved their stem cell properties and tumorigenicity, even after long-term culture. This would be a suitable in?vitro model to study cancer stem-like cells in retinoblastoma and to develop chemotherapeutic drugs and strategies.     

人脑胶质瘤组织中分离与培养肿瘤干细胞

目的 从胶质瘤组织中培养、分离肿瘤干细胞,并初步探讨其生物学特性。方法采集8例人脑胶质瘤手术标本,剪碎、胰酶消化,滤网过滤收集细胞。淋巴细胞分离液除去其中的红细胞,用含EGF、LIF和bFGF的无血清培养液培养,形成细胞球体后经免疫磁珠分离获取CD133^＋细胞,用有限稀释法继续在上述无血清培养基中培养得到肿瘤细胞球后连续传代培养。取第5代肿瘤干细胞,用含10％FBS培养液诱导分化。分化前后用Nestin、MAP2、GFAP免疫细胞化学染色检测肿瘤干细胞及其分化细胞的相应标志物。结果在1例间变性星形细胞、室管膜细胞混合瘤中克隆到了CD133^＋细胞,这些细胞在体外培养时,能稳定维持于球形生长状态（3个月,14代）,在适合的环境中随时能自我更新和增殖,并分化成MAP2^＋的瘤性神经元和GFAP^＋的瘤性胶质细胞,而CD133^-细胞则无此特性。结论在胶质瘤组织中有肿瘤干细胞存在,这些细胞在体外能长期培养和传代,可为进一步研究胶质瘤的细胞生物学和分子生物学特征开拓新途径。     

9L脑胶质瘤干细胞模型建立及MRI成像表现

目的:建立9L脑胶质瘤干细胞F344大鼠载瘤模型,采用3.0T磁共振成像评价肿瘤生长。方法:采用流式细胞仪分选CD133表达阳性细胞群,免疫荧光检测分选后细胞群的干细胞标记CD133、Nestin的表达情况。利用三维立体定向技术建立脑胶质瘤干细胞大鼠载瘤模型,定期行MR检查,观察颅内肿瘤生长情况。HE染色和免疫组织化学染色法观察肿瘤组织细胞形态和GFAP、S-100蛋白表达情况。结果:分选后细胞群CD133、Nestin蛋白表达阳性;干细胞荷瘤大鼠中位生存时间为（21.00±0.33）天;接种后1~3周MR扫描示肿瘤持续生长,增强扫描瘤体显像清晰,第3周末瘤周水肿显著;病理结果示肿瘤浸润生长,局部见出血、坏死,免疫组化示肿瘤组织胶质纤维GFAP阳性, S-100蛋白弱阳性。结论:流式技术分选9L脑胶质瘤干细胞建立的F344大鼠脑胶质瘤模型稳定可靠,符合恶性胶质瘤生物学特点;3.0T MR扫描仪能够动态观察脑胶质瘤生长状态。     

Isolation of cancer stem-like cells from a side population of a human glioblastoma cell line,SK-MG-1

Accumulating evidence suggests that in several types of brain tumors, including glioma, only a phenotypic subset of tumor cells called brain cancer stem cells (BCSCs) may be capable of initiating tumor growth. Recently, the isolation of side population (SP) cells using Hoechst dye has become a useful method for obtaining cancer stem cells in various tumors. In this study, we isolated cancer stem-like cells from human glioma cell lines using the SP technique. Flow cytometry analysis revealed that SK-MG-1, a human glioblastoma cell line, contained the largest number of SP cells among the five glioma cell lines that were analyzed. The SP cells had a self-renewal ability and were capable of forming spheres in a neurosphere culture medium containing EGF and FGF2. Spheres derived from the SP cells differentiated into three different lineage cells: neurons, astrocytes and oligodendrocytes. RT-PCR analysis revealed that the SP cells expressed a neural stem cell marker, Nestin. The SP cells generated tumors in the brains of NOD/SCID mice at 8 weeks after implantation, whereas the non-SP cells did not generate any tumors in the brain. These results indicate that SP cells isolated from SK-MG-1 possess the properties of cancer stem cells, including their self-renewal ability, multi-lineage differentiation, and tumorigenicity. Therefore, the SP cells from SK-MG-1 may be useful for analyzing BCSCs because of the ease with which they can be handled and their yield.     

Antitumor effects of genetically engineered stem cells expressing yeast cytosine deaminase in lung cancer brain metastases via their tumor-tropic properties

Although mortality related with primary tumors is approximately 10%, metastasis leads to 90% of cancer-associated death. The majority of brain metastases result from lung cancer, but the metastatic mechanism remains unclear. In general, chemotherapy for treating brain diseases is disrupted by the brain blood barrier (BBB). As an approach to improve treatment of lung cancer metastasis to the brain, we employed genetically engineered stem cells (GESTECs), consisting of neural stem cells (NSCs) expressing a suicide gene. Cytosine deaminase (CD), one of the suicide genes, originating from bacterial (bCD) or yeast (yCD), which can convert the non-toxic prodrug, 5-fluorocytosine (5-FC), into 5-fluorouracil (5-FU), can inhibit cancer cell growth. We examined the therapeutic efficacy and migratory properties of GESTECs expressing yCD, designated as HB1.F3.yCD, in a xenograft mouse model of lung cancer metastasis to the brain. In this model, A549 lung cancer cells were implanted in the right hemisphere of the mouse brain, while CM-DiI pre-stained HB1.F3.yCD cells were implanted in the contralateral brain. Two days after the injection of stem cells, 5-FC was administered via intraperitoneal injection. The tumor-tropic effect of HB1.F3.yCD was evident by fluorescent analysis, in which red-colored stem cells migrated to the lung tumor mass of the contralateral brain. By histological analysis of extracted brain, the therapeutic efficacy of HB1.F3.yCD in the presence of 5-FC was confirmed by the reduction in density and aggressive tendency of lung cancer cells following treatment with 5-FC, compared to a negative control or HB1.F3.yCD injection without 5-FC. Taken together, these results indicate that HB1.F3.yCD expressing a suicide gene may be a new therapeutic strategy for lung cancer metastases to the brain in the presence of a prodrug.     

三维无血清条件培养结合抗癌药物分离人骨肉瘤肿瘤干细胞

目的探讨无血清三维条件培养结合抗癌药物分离及鉴定人骨肉瘤肿瘤干细胞的可行性。方法将来源于人体的骨肉瘤细胞种植于1．2％藻酸盐凝胶中,并置于添加有阿霉素（Epirubicin,0．8μg／ml）的无血清DMEM／F12条件培养基中培养。培养7～10天后,可见凝胶内出现由单细胞增殖形成的单克隆球。取出该单克隆球,并通过细胞免疫荧光（Oct3／4和Nanog）、体内致瘤实验,检测该单克隆球细胞的生物特性。结果单克隆球主要由Oct3／4和Nanog阳性细胞组成,这些阳性细胞具有明显的致瘤作用：结论分离所得的单克隆细胞既能表达部分干细胞基因（Oct3／4和Nanog）。又表现出明显的抗肿瘤药物性和体内致瘤性,三维无血清条件培养结合抗癌药物分离所得的单克隆骨肉瘤细胞可能为人骨肉瘤干细胞。     

Correlation between glioblastoma stem-like cells and tumor vascularization

Glioblastoma multiforme (GBM) is the most lethal type of brain tumor. The formation of abnormal, dysfunctional tumor vasculature and glioblastoma stem-like cells (GSCs) are believed to be the major components of the inability to treat these tumors effectively. We analyzed 70 glioblastoma samples by immunohistochemistry and double immunofluorescence staining. The immunohistochemical expression of the putative brain tumor stem cell markers CD133 and Nestin in paraffin sections was analyzed using morphometry. In all GBM samples, CD133 or Nestin was expressed in tumor and endothelial cells. Double immunofluorescence stainings showed that the two different marked GSCs were found accumulated around the CD31+ blood vessels and CD133/CD31 or Nestin/CD31 co-expression was found in the endothelial cells and GSCs. Furthermore, the vascular endothelial growth factor (VEGF) and the endothelial marker CD31 were co-expressed in GSCs. Therefore, GSCs not only showed distinct perivascular distribution but were capable of differentiating into endothelial cells. We demonstrate that GSCs contribute directly to the tumor vasculature by endothelial cell differentiation. GSCs and tumor vascularization are closely related to each other, not only in the regional distribution but also in biological function. These findings describe a new mechanism for tumor vasculo-genesis and may provide new insights for targeted therapy against brain tumors.