人肺腺癌细胞系中肿瘤干细胞的分离培养及鉴定*

目的:从人肺腺癌细胞系A 549 及H 1299中分离富集含肿瘤干细胞的细胞球并鉴定其生物学特性。方法:用无血清悬浮培养的方法从人肺腺癌A 549 及H 1299细胞株中富集得到肿瘤细胞球。将肿瘤细胞球传代扩增,体外利用CCK-8 法、平皿克隆以及Transwell 小室实验,研究细胞球的增殖情况、自我更新和侵袭转移能力;通过RT-PCR 检测干细胞特异性转录因子Oct4、Nanog基因表达情况;体内利用裸鼠移植瘤形成实验研究肺癌细胞球的成瘤能力。鉴定细胞球的肿瘤干细胞特性。结果:在无血清悬浮培养下,A 549 及H 1299细胞株3~ 6 天后能形成稳定传代的肿瘤悬浮球,悬浮球的体外自我更新、克隆形成和侵袭转移等能力均高于其亲本细胞（P < 0.05）;干细胞核心基因Oct4 和Nanog的mRNA 表达水平明显升高（P < 0.05）;A 549 悬浮球可以明显提高裸鼠体内成瘤能力。结论:通过无血清悬浮培养法可有效富集A 549 及H 1299细胞系中的干细胞成分,该法可成为快速易行构建肺腺癌干细胞模型的方法。      

肺癌A549细胞株中ALDH1+细胞的生物学功能研究

探讨肺癌A549细胞株中具有肿瘤干细胞特性的ALDH1+细胞的生物学功能特性。方法:运用流式细胞仪分选肺癌A549细胞株中ALDH1+细胞,并通过肿瘤球培养、MTT实验、平板克隆、Transwell小室迁移实验、裸鼠体内成瘤实验来验证ALDH1+细胞的自我更新、增殖克隆、迁移及致瘤能力。结果:ALDH1+ A549细胞的肿瘤球形成能力、增殖克隆、迁移和体内成瘤能力明显高于ALDH1- A549细胞和未经分选的A549细胞。结论:A549细胞株中ALDH1+ A549细胞具有自我更新、增殖、迁移和高致瘤能力的肿瘤干细胞特性,ALDH1可作为分选肺癌肿瘤干细胞的标志物。      

人肺腺癌干细胞的分离及鉴定

目的：从人肺腺癌细胞株中分离及鉴定具有干细胞特征的高致瘤性癌干细胞。方法：采用磁性细胞分选（magnetic activated cell sorting，MACS）技术将肺腺癌细胞分成多个亚群，然后应用流式细胞及RT-PCR技术检测干细胞相关标志表达，通过NOD-SCID小鼠移植评估其致瘤性。结果：在A549和SPC-A肺腺癌细胞中发现一个新颖的癌细胞亚群，此类癌细胞的表型特征为CD24^＋IGF-1R^＋，具有高侵袭性和高致瘤性，在NOD-SCID小鼠中仅需移植100个细胞即可形成肿瘤，其致瘤能力是上述标志阴性细胞的1000倍。此外，这些细胞表达胚胎干细胞标志（OCT4和Bmi-1）及肺干细胞标志（CCSP，SP-C，TTF-1和Gremlin），类似小鼠肺脏细支气管肺泡干细胞（bronchioalveolar stem cells，BASC），并具有自主生长特性，能够在无血清条件下长期培养。结论：人体肺腺癌中CD24^＋IGF-1R^＋细胞属于BASC样癌干细胞。     

人肺癌A549细胞系肿瘤干细胞的筛选和鉴定

背景与目的肺癌干细胞是肺癌恶性表型的根源和潜在的治疗靶点,从人肺癌A549细胞株中分离肺癌干细胞,观察特异性干细胞标志物分子的表达,为进一步的干细胞研究提供试验基础。方法接种肺癌A549细胞株,经流式细胞术,特异性筛选分离肺癌干细胞,观察克隆形成能力、细胞增殖能力和体外致瘤能力的差别,并分别用RT-PCR和Westernblot的方法分析干细胞标志物分子CD133和ABCG2的表达。结果经过流式细胞仪成功分选了人肺腺癌A549细胞系SP细胞亚群,结果表明此SP细胞亚群约占A549细胞总数的5.93%,经维拉帕米处理后Hoechest33342阴性/弱阳性细胞含量下降为0.32%,SP细胞克隆形成能力,细胞增殖能力和体外致瘤能力均明显高于非SP细胞。RT-PCR和Westernblot结果发现,筛选分离的肺癌SP细胞群高表达干细胞标志物分子CD133和ABCG2。结论通过流式细胞术可以筛选分离高表达CD133和ABCG2分子的肺癌干细胞,可用于进一步的研究中。     

人小细胞肺癌细胞株H446侧群细胞的生物学特征

背景与目的:肿瘤干细胞学说的提出为肿瘤治疗提供了新的靶点和方向,但肿瘤干细胞的分离纯化一直是个难题。本研究拟从人小细胞肺癌细胞株H446中分离并鉴定出具有干细胞特性的侧群(SP)细胞,研究其生物学特征,为肿瘤干细胞的分离纯化奠定基础。方法:采用荧光激活细胞分选(FACS)技术分选得到H446细胞中SP细胞和非侧群(NSP)细胞,并检测纯度。观察形成悬浮肿瘤细胞球的能力,采用逆转录-聚合酶链反应(RT-PCR)及荧光定量PCR检测这两种细胞亚群中CD133、ABCG2、NucleosteminmRNA水平。MTT法比较SP细胞、NSP细胞及未分选细胞体外增殖能力及耐药性差异,流式细胞仪检测体外分化能力,裸鼠成瘤实验检测体内成瘤能力。结果:荧光显微镜下H446细胞中Hoechst33342阴性细胞约为(5.1±0.2)%。流式细胞分选结果显示,H446中SP细胞比例为(6.3±0.1)%。SP细胞在无血清培养基中形成悬浮肿瘤细胞球的能力强于NSP细胞。CD133、ABCG2在SP细胞中的表达是NSP细胞的(21.60±0.26)倍、(7.10±0.14)倍,差异有统计学意义(P<0.01);Nucleostemi...     

鼻咽癌肿瘤干细胞样细胞亚群的分离及初步鉴定

  目的   分离和鉴定具有肿瘤干细胞特性的鼻咽癌球形成细胞亚群。   方法   利用无血清干细胞球悬浮培养技术从不同分化程度鼻咽癌细胞株中分离成球细胞,然后利用MTT法,软琼脂克隆形成实验,分别评价成球细胞的耐药性、克隆形成能力,最后利用RT-PCR和免疫荧光细胞技术分析干性基因及Wnt信号通路关键转录因子β-catenin在成球及未成球细胞中的表达情况。   结果   低分化鼻咽癌细胞含有较高成球细胞,而高分化细胞株CNE-1中未见成球细胞。与CNE-2相比较,CNE-2S（来源于CNE-2的成球细胞）具有较强的抗肿瘤药物耐药性、克隆形成能力、高表达干性基因,且β-catenin在胞浆和核内都呈高表达。   结论   本研究分离到干细胞样鼻咽癌成球细胞亚群,为最终靶向杀灭鼻咽癌肿瘤干细胞提供了可能。      

CD133阳性/阴性肺癌细胞的分选、鉴定及差异基因的筛选

背景与目的研究表明多种实体肿瘤中存在肿瘤干细胞(cancer stem cells,CSCs),肿瘤干细胞与非肿瘤干细胞的生物学特性存在已有的明显差异,而CD133被认为是肿瘤干细胞的标记物,因此CD133阳性细胞与CD133阴性细胞可能存在明显差异。本研究通过分选人肺腺癌A549细胞中的CD133阳性及CD133阴性细胞,鉴定两组细胞的生物学特性并在人组织标本进行验证,利用基因芯片筛选转移相关差异基因。方法采用磁式分选(magnetic activated cell sorting,MACS)的方法对人肺腺癌A549中CD133阳性细胞、CD133阴性细胞进行分选,通过无血清条件培养、平板克隆、血清诱导分化及基因芯片等实验,比较两组细胞"sphere"形成、细胞增殖、细胞分化以及差异基因,并在人组织标本进行CD133表达与临床特性的验证分析。结果 CD133阳性细胞能在无血清培养基中悬浮生长并形成"sphere";其平均克隆形成率(57.1%)明显高于CD133阴性细胞(3.3%);CD133阳性细胞能被血清诱导分化、表达腺癌标志物CK7;两组细胞中的19个转移基因表达水平相差两倍或以上,差异最高达12倍;肺癌组织中CD133阳性细胞主要分布于癌巢周边,数量稀少,其表达与肿瘤组织学分型、分级及临床分期无关。结论 CD133阳性肺腺癌A549细胞具有CSCs特性;两组细胞在转移相关基因的表达存在明显差异,其中CD82可能在CD133阳性细胞的转移机制中起重要作用。     

肾癌细胞株786-0侧群细胞生物学特性与XIAP mRNA表达的研究

目的 肿瘤干细胞在肿瘤复发和耐药中起着关键作用,侧群(side population,SP)细胞中富含肿瘤干细胞.本研究探讨肾癌786-0细胞株中SP细胞的生物学特性及凋亡抑制蛋白XIAP在SP中的表达.方法 制备肾癌786-0细胞株单细胞悬液,Hoechst33342染色,流式细胞荧光激活技术分选出肾癌786-0细胞系中的SP细胞和非侧群(non-SP,NSP)细胞2个亚群,MTT法绘制细胞生长曲线,比较SP细胞和NSP细胞的增殖能力;无血清悬浮培养观察两组亚群细胞肿瘤球形成能力,流式细胞仪检测两组亚群细胞体外分化能力;实时荧光定量PCR法检测SP细胞、NSP细胞及未经分选的肾癌786-0细胞XIAP mRNA的表达情况.结果 流式细胞分选结果显示,肾癌786-0细胞株中SP细胞所占比例为(2.9±0.1)％.细胞生长曲线结果显示,SP细胞增殖速度快,与NSP细胞增殖能力比较,差异有统计学意义,t=4.32,P=0.033.SP细胞在无血清培养基中的肿瘤球形成能力强于NSP细胞;无血清培养2周后SP细胞亚组SP细胞所占比例下降为(18.1±0.3)％,提示SP细胞可以分化为NSP细胞.XIAP mRNA在SP细胞中的表达量为10.74±0.25,与NSP细胞亚组及未经分选的786-0细胞比较差异有统计学意义,F=61.02,P=0.012.结论 肾癌786-0细胞株中存在具有干细胞特性的SP细胞,高表达凋亡抑制蛋白XIAP,SP细胞可作为肾癌分子靶向治疗研究的切入点.     

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。     

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。     

Fluorouracil selectively enriches stem-like cells in the lung adenocarcinoma cell line SPC

Most adult stem cells are in the G0 or quiescent phase of the cell cycle and account for only a small percentage of the cells in the tissue. Thus, isolation of stem cells from tissues for further study represents a major challenge. This study sought to enrich cancer stem cells and explore cancer stem-like cell clones using 5-fluorouracil (5-FU) in the lung adenocarcinoma cell line, SPC. Proliferation inhibition was analyzed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays, according to which half maximal inhibitory concentration values were calculated. Expression levels of stem cell markers after treatment with 5-FU were examined using immunofluorescence and Western blotting. Additionally, side population (SP) cells were sorted using FACS. Properties of SP cells were evaluated by using Transwell, colony-forming assays, and tumor formation experiments. 5-FU greatly inhibits proliferation, especially of cells in S phase. SP cells possess greater invasive potential, higher clone-forming potential, and greater tumor-forming ability than non-SP cells. Treatment with 5-FU enriches the SP cells with stem cell properties in human lung adenocarcinoma cell lines.     

Identification of a cancer stem-like population in the Lewis lung cancer cell line

Objective: Although various human cancer stem cells (CSCs) have been defined, their applications are restricted to immunocompromised models. Developing a novel CSC model which could be used in immunocompetent or transgenic mice is essential for further understanding of the biomolecular characteristics of tumor stem cells. Therefore, in this study, we analyzed murine lung cancer cells for the presence of CSCs. Methods: Side population (SP) cells were isolated by fluorescence activated cell sorting, followed by serum-free medium (SFM) culture, using Lewis lung carcinoma cell (LLC) line. The self-renewal, differentiated progeny, chemosensitivity, and tumorigenic properties in SP and non-SP cells were investigated through in vitro culture and in vivo serial transplantation. Differential expression profiles of stem cell markers were examined by RT-PCR. Results: The SP cell fraction comprised 1.1% of the total LLC population. SP cells were available to grow in SFM, and had significantly enhanced capacity for cell proliferation and colony formation. They were also more resistant to cisplatin in comparison to non-SP cells, and displayed increased tumorigenic ability. Moreover, SP cells showed higher mRNA expression of Oct-4, ABCG2, and CD44. Conclusion: We identified SP cells from a murine lung carcinoma, which possess well-known characteristics of CSCs. Our study established a useful model that should allow investigation of the biological features and pharmacosensitivity of lung CSCs, both in vitro and in syngeneic immunocompetent or transgenic/knockout mice.     

人肺腺癌A549细胞系干细胞相关亚群的分离与鉴定

目的 分离人肺腺癌A549细胞系中的侧群(SP)细胞亚群并探讨其细胞特性.方法 采用免疫组化法检测人肺腺癌A549细胞系中ABCG2蛋白的表达.采用流式细胞术分选A549细胞系中的SP和非SP细胞亚群,并检测两亚群细胞的分化功能.采用逆转录聚合酶链反应(RT-PCR)方法检测两亚群细胞的ABCG2蛋白表达,通过两亚群细胞的生长曲线、细胞分裂指数、细胞周期各时相分布、平板克隆形成实验、体外侵袭和迁移实验、化疗药敏试验、细胞内药物浓度测定以及裸鼠移植瘤实验,比较两亚群细胞的生物学行为,并用RT-PCR和免疫组化方法检测移植瘤组织中ABCG2的表达.结果 A549细胞系中ABCG2蛋白的阳性表达率为2.13%.通过流式细胞术能成功分选得到SP细胞和非SP细胞,SP细胞亚群可产生SP及非SP两种细胞,而非SP细胞只能产生非SP细胞.SP细胞表达ABCG2,非SP细胞则不表达.两细胞亚群的增殖、迁移能力相似,吸光度、分裂指数、细胞周期时相分布和细胞体外迁移实验穿过滤膜的细胞数差异均无统计学意义(均P＞0.05),但SP细胞的侵袭能力和成瘤能力强于非SP细胞,细胞体外侵袭实验穿过滤膜的细胞数、体外细胞克隆形成数和移植瘤成瘤率均高于非SP细胞(P＜0.01,P＜0.01,P＜0.05).SP细胞和非SP细胞对顺铂(DDP)的敏感性和细胞内药物浓度相似,非SP细胞对5-氟尿嘧啶(5-Fu)、依托泊苷(VP-16)、长春瑞滨(NVB)和吉西他滨(GEM)的敏感性及细胞内药物浓度则高于SP细胞(均P＜0.01).结论 人肺腺癌A549细胞系SP细胞亚群富集了肺癌干细胞,通过流式细胞仪分选肺腺癌SP细胞亚群是分离肺腺癌干细胞的有效方法.

Abstract：

Objective To isolate and characterize the side population cells(SP cells) in the lung adenocarcinomas cell line A549. Methods The protein expression of ABCG2 in human lung adenocarcinoma cell line A549 was detected by immunohistochemistry.SP and NSP cells in the cell line A549 were isolated by FACS,and their differentiation was analysed.ABCG2 expression in the two cell subsets was detected by RT-PCR.The cell growth curves,cell division indexes,cell cycles,plate clone formation tests,migration and invasion assays,chemotherapeutic susceptibility tests,tests of the intracellular drug levels,and the tumor cell implantation experiments on nude mice were applied to study the biological properties of the two cell subsets.The expression of ABCG2 in the transplanted tumor in nude mice was detected by immunohistochemistry and RT-PCR. Results The positive rate of ABCG2 expression in the A549 cells by immunohistochemistry was 2.13%.SP and NSP cells were isolated by FACS.The SP cells could produce both SP and NSP cells,while NSP cells only produced NSP cells.SP cells expressed ABCG2,but NSP cells did not.The proliferation and migration abilities of the two cell subsets were similar,but the invasion and tumorigenic ability of SP cells was significantly higher than that of NSP cells.The susceptibilities to DDP and its intracellular levels of the two cell subsets were similar,but the susceptibilities to 5-FU,VP16,NVB and GEM and their intracellular levels of NSP cells were significantly higher than those of the SP cells. Conclusions SP cells in the human lung adenocarcinomas cell line A549 is enriched with tumor stem cells.An effective way to get lung adenocarcinomas stem cells is to isolate SP cells by FACS.     

Human pancreatic adenocarcinoma contains a side population resistant to gemcitabine

ABSTRACT: BACKGROUND: Therapy resistance remains one of the major challenges to improve the prognosis of patients with pancreatic cancer. Chemoresistant cells, which potentially also display cancer stem cell (CSC) characteristics, can be isolated using the side population (SP) technique. Our aim was to search for a SP in human pancreatic ductal adenocarcinoma (PDAC) and to examine its chemoresistance and CSC([MINUS SIGN]like) phenotype. METHODS: Human PDAC samples were expanded in immunodeficient mice and first-generation xenografts analyzed for the presence of a Hoechst dye-effluxing SP using flow cytometry (FACS). To investigate chemoresistance of the SP, mice bearing PDAC xenografts were treated with gemcitabine and SP proportion determined. In addition, the SP and the main tumour cell population (MP) were sorted by FACS for RNA extraction to profile gene expression, and for culturing under sphere-forming conditions. RESULTS: A SP was identified in all PDAC samples, analyzed. This SP was more resistant to gemcitabine than the other tumour cells as examined in vivo. Whole-genome expression profiling of the SP revealed upregulation of genes related to therapy resistance, apoptotic regulation and epithelial-mesenchymal transition. In addition, the SP displayed higher tumourigenic (CSC) activity than the MP as analyzed in vitro by sphere-forming capacity. CONCLUSION: We identified a SP in human PDAC and uncovered a chemoresistant and CSC-associated phenotype. This SP may represent a new therapeutic target in pancreatic cancer.Trial registrationClinicaltrials.gov NCT00936104.     

Isolation and characterization of cancer stem-like side population cells in human oral cancer cells

Recent studies suggest that cancer stem cells may be responsible for tumorigenesis and contribute to some individuals’ resistance to cancer therapy. Some studies demonstrate that side population (SP) cells isolated from diverse cancer cell lines harbor stem cell-like properties; however, there are few reports examining the role of SP cells in human oral cancer. To determine whether human oral cancer cell lines contain a SP cell fraction, we first isolated SP cells by fluorescence activated cell sorting, followed by culturing in serum-free medium (SFM) using the SCC25 tongue cancer cell line, so that SP cells were able to be propagated to maintain the CSC property. Differential expression profile of stem cell markers (ABCG2, Oct-4 and EpCAM) was examined by RT-PCR in either SP cells or non-SP cells. Growth inhibition by 5-FU was determined by the MTT assay. Clonogenic ability was evaluated by colony formation assay. SCC25 cells contained 0.23% SP cells. The fraction of SP cells was available to grow in SFM cultures. SP cells showed higher mRNA expression of stem cell markers (ABCG2, Oct-4 and EpCAM) as compared with non-SP cells. Moreover, SP cells demonstrated more drug resistance to 5-FU, as compared with non-SP cells. The clone formation efficiency of SP cells was significantly higher than non-SP cells at an equal cell number (P < 0.01). We isolated cancer stem-like SP cells from an oral cancer cell line. SP cells possessed the characteristics of cancer stem cells, chemoresistance, and high proliferation ability. Further characterization of cancer stem-like SP cells may provide new insights for novel therapeutic targets.     

膀胱癌细胞系T24侧群细胞的分离及初步鉴定

目的:检测和分选人类膀胱癌细胞系T24中的侧群（side population,SP）细胞,并初步鉴定其癌干细胞特性,为癌干细胞的分离纯化奠定基础。方法:采用荧光激活细胞分选（FACS）技术,分选得到T24细胞中的侧群细胞,并检测其比例。采用反转录聚合酶链反应（RT-PCR）技术检测侧群细胞中ABCG2的表达情况;继而将侧群细胞培养于无血清培养基中,观察形成悬浮肿瘤细胞球的能力。结果:流式细胞分选结果显示:T24细胞中侧群细胞的比例约为3.6%。和对应的母系T24细胞相比,T24侧群细胞的ABCG2表达增高。培养于无血清培养基中的侧群细胞成簇生长,并形成肿瘤细胞球。结论:人类膀胱癌细胞系T24中存在具有癌干细胞特性的侧群细胞。     

Identification of side population cells from bladder cancer cells by DyeCycle Violet staining

Side population (SP) cells can be used to identify putative cancer stem cells (CSC), but this technique is hampered by the requirement for an ultraviolet (UV) laser source. DyeCycle Violet reagent (DCV) is a DNA-binding dye that can be used in the common violet laser diode (VLD)-equipped flow cytometer. In this paper, we analyzed SP cells from several bladder cancer cell lines using either Hoechst 33342 or DCV staining. The Hoechst 33342-stained SP cells were identified with a UV-equipped flow cytometer, while the DCV-stained SP cells were identified with a VLD-equipped flow cytometer. DCV staining was also used to sort SP and non-SP (NSP) cells from SW780 cells. Further analysis revealed that SP cells could give rise to both SP and NSP cells. The colony-forming ability of SP cells was significant greater than that of NSP cells. When injected into nude mice, as few as 1 x 10(3) SP cells could initiate tumors in eight of twelve injection sites. In contrast, the injection of NSP cells into nude mice failed to initiate tumors. RT-PCR data showed that the expression of ABCG2, MDRI, Bmi-1 and Oct-4 differed between SP and NSP cells, suggesting that SP cells possess some stem cell characteristics. We conclude that SP cells identified by DCV staining are capable of asymmetric division, self-renewal and tumor initiation. Our study also indicates that DCV is a useful reagent for the identification of SP cells.     

Autologous CTL response against cancer stem-like cells/cancer-initiating cells of bone malignant fibrous histiocytoma

Malignant fibrous histiocytoma (MFH) of the bone is an aggressive tumor with high rates of local recurrence and metastasis. The development of novel therapeutic approaches is critical to improve the prognosis of patients with MFH. We reported previously that the side population (SP) cells of the MFH2003 bone MFH cell line have the characteristics of cancer stem-like cells (CSC)/cancer-initiating cells. In the present study, to establish immunotherapy targeting CSC, we analyzed cell surface immune molecules on SP cells of the MHF2003 cell line, as well as autologous CTL responses against these SP cells in the tumor microenvironment and peripheral circulating lymphocytes, using autologous tumor-infiltrating lymphocytes and autologous CTL clones derived from peripheral blood, respectively. We found that the SP cells expressed human leukocyte antigen (HLA) Class I molecules on the cell surface. The autologous tumor-infiltrating lymphocyte line TIL2003 recognized both the SP and main population cells of the MFH2003 cell line. Next, we induced the CTL clone Tc4C-6 by mixed lymphocyte tumor cell culture using autologous peripheral blood mononuclear cells and freshly isolated SP cells, followed by a limiting dilution procedure. The Tc4C-6 clone showed specific cytotoxicity against the SP cells. Moreover, the cytotoxicity against SP cells was blocked by the anti-HLA Class I antibody W6/32. In conclusion, the findings of the present study support the idea that CSC of bone MFH are recognized by autologous CTL in the tumor microenvironment and peripheral circulating lymphocytes. Thus, CTL-based immunotherapy could target CSC of bone sarcoma to help prevent tumor recurrence.     

Recombinant human endostatin could eliminate the pro-angiogenesis priority of SP cells sorted from non-small cell lung cancer cells

Purpose

To ascertain the biologic significance of lung cancer Side population (SP) cells, which represent putative cancer stem cells (CSC) in the absence of consensus biomarkers for tumor-specific CSC.

Materials and methods

We sorted and analyzed the angiogenic features of SP cells, isolated from tumor cell lines based on the exclusion of the DNA dye Hoechst 33342, from the NSCLC cell lines A549 and H460.

Results

Compared with non-SP cells, mRNA of vascular endothelial growth factor (VEGF)-A, VEGF-B, angiopoietin (ang)-1, ang-2, fibroblast growth factor-2 (FGF-2), cyclooxygenase-2 (Cox-2) and interleukin-8 (IL-8) were over-expressed in SP cells accompanied by over-expression of ABCG2 and MDR1 mRNA. The supernatant of cultured SP cells could significantly induce migration of human umbilical vein endothelial cells, while recombinant human endostatin (Endostar 25^?) could inhibit the migration.

Conclusions

This study revealed that the NSCLC SP cells might represent CSCs and possess pro-angiogenic properties, and antiangiogenesis represent a potential therapy.     

人前列腺癌细胞系DU 145中肿瘤干细胞样侧群细胞的分离

目的:分离人前列腺癌细胞系DU 145中的侧群(side population,SP)细胞,并初步分析其生物学特性。方法:采用荧光激活细胞分类(fluorescence activated cell sorting,FACS)技术,从DU 145细胞中分离出侧群细胞,并检测其比例;继而培养于无血清培养基中,观察其生长特性。采用反转录聚合酶链反应(RT-PCR)技术检测侧群细胞中ABCG2的表达水平。结果:DU 1 4 5细胞中存在含量极少的侧群细胞,比例约1.1%;培养于无血清培养基中成簇生长。和对应的母系DU 145细胞相比,DU 145侧群细胞的ABCG2表达增高。结论:人前列腺癌细胞系DU 145中存在具有肿瘤干细胞特性的侧群细胞。