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。      

不同乳腺癌干细胞亚群的自我更新和致瘤能力差异

目的 分析原代培养乳腺癌细胞中不同乳腺癌干细胞亚群的自我更新、致瘤能力差异。方法 采用流式细胞术和免疫荧光实验,从乳腺癌原代培养细胞中分选、鉴定CD44⁺CD24^-/low、ALDH1⁺和ALDH1⁺CD44⁺CD24^-/low细胞亚群,分析各分选细胞占总肿瘤细胞的比例;通过克隆形成实验观察各组细胞的自我更新能力;通过裸鼠致瘤实验观察各组细胞的致瘤能力。结果 CD44+CD24^-/low细胞占总细胞比例的7.2%,ALDH1⁺细胞所占比例为4.6%,ALDH1⁺CD44⁺CD24^-/low细胞所占比例为1.5%。三组细胞自我更新和致瘤能力由强至弱依次为ALDH1⁺CD44⁺CD24^-/low、ALDH1⁺、CD44⁺CD24^-/low细胞,各组细胞间比较差异均存在统计学意义（P<0.05）。 结论 乳腺癌组织中CD44+CD24-/low、ALDH1⁺和ALDH1⁺CD44⁺CD24^-/low三组乳腺癌干细胞亚群之间的自我更新和致瘤能力有明显差异,ALDH1⁺CD44⁺CD24^-/low亚群细胞具有最强的自我更新和致瘤能力,提示ALDH1⁺CD44⁺CD24^-/low可能是更具有特异性的乳腺癌干细胞标志物。     

高转移肺癌细胞株的建立及其肿瘤干细胞生物学特性

 目的 研究高转移肺腺癌细胞株的肿瘤干细胞生物学特征。方法 肺腺癌细胞系A549接种裸鼠皮下成瘤后,取肺的转移灶,通过机械分离法获取肺转移细胞,体外扩大培养后,再次接种裸鼠。如此反复接种裸鼠,获得稳定肺转移的细胞株A549-V13。采用无血清悬浮培养及PKH26染色确定A549-V13存在肿瘤干细胞。流式细胞术（FACS）检测和分选A549和A549-V13中肿瘤干细胞标志物CD133的表达并进行体内外生物学特征实验。结果 建立稳定高转移A549-V13细胞株。无血清悬浮培养A549-V13,7天后形成的球形细胞团中存在单个PKH26阳性细胞。FACS检测显示,与A549中CD133⁺细胞相比,高转移A549-V13细胞株中CD133⁺细胞的表达比例显著提高4.85倍。A549-V13中CD133⁺细胞具有更强的自我更新能力,侵袭能力提高1.42倍,耐药能力也显著增强,其IC₅₀提高1.26倍,A549-V13的CD133⁺细胞在裸鼠皮下接种2×102个细胞3月致瘤4/6,而接种2×10²个A549的CD133⁺细胞3月才致瘤2/6。结论 建立高转移肺癌细胞株A549-V13,伴随CD133⁺细胞表达比例的增加,其体内外生物学功能显著增强。     

乙醛脱氢酶1作为喉癌Hep-2细胞系肿瘤干细胞标志物的实验研究

目的 探讨乙醛脱氢酶1(ALDH1)在人喉癌Hep-2细胞系中的表达,观察ALDH1高表达细胞的体外生长特性,确定喉癌Hep-2细胞系肿瘤干细胞标志物.方法 采用荧光细胞化学染色和流式细胞术观察和检测喉癌Hep-2细胞系中的ALDH1的表达.采用流式分选术分离ALDH1高表达细胞,以四甲基偶氮唑蓝(MTT)法观察ALDH1不同亚群细胞的体外增殖能力,以流式细胞术检测ALDH1高表达细胞的体外分化能力.采用裸鼠成瘤实验比较不同亚群细胞的成瘤能力.结果 喉癌Hep-2细胞系中ALDH1呈不同程度的表达,其中ALDH1高表达细胞占2.9％±0.6％.ALDH1高表达细胞的体外增殖能力高于ALDH1低表达和未分选细胞.在含血清的培养液中,经过6d培养,ALDH1高表达细胞由最初分选后的94.2％±3.8％下降至分选前水平.ALDH1高表达细胞的成瘤能力显著高于其他亚群.结论 喉癌Hep-2细胞系中,ALDH1高表达细胞具有很强的体外分化能力、增殖能力和成瘤能力,可以作为Hep-2细胞系肿瘤干细胞的标志物之一.     

Id1在人肺癌细胞系A549肿瘤细胞球中的表达

目的:探讨Id1在人肺癌细胞系A549肿瘤细胞球中的表达情况,为肺癌干细胞的基因靶向治疗提供理论依据。方法:应用干细胞无血清培养技术培养A549细胞肿瘤细胞球,采用克隆形成实验检测肺癌肿瘤球细胞增殖能力,流式细胞术检测ABCG2在肺癌肿瘤球细胞中的表达情况,Western blotting检测Id1在肺癌肿瘤球细胞中的表达情况。结果:与贴壁细胞相比,人肺癌细胞系A549肿瘤细胞球细胞具有较强的克隆能力,且高表达ABCG2,符合肺癌干细胞的特点,Id1在人肺癌细胞系A549肿瘤细胞球细胞中高表达。结论:Id1可能成为靶向肺癌干细胞肺癌治疗的靶点。     

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。     

RNA干扰沉默 PIN1 对肺癌A549细胞增殖、细胞周期和成瘤的影响

目的： 应用RNA干扰技术沉默肺癌A549细胞中 PIN1 （protein interacting with N1MA1）基因的表达,探讨其对A549细胞增殖、细胞周期和裸鼠成瘤能力的影响。 方法: 构建靶向 PIN1 基因的shRNA真核表达质粒pGPU6-GFP-Neo-PIN1和无义对照质粒pGPU6-GFP-Neo,以脂质体法转染A549细胞,G418筛选稳定沉默 PIN1 基因的细胞株。Real-time PCR和Western blotting验证 PIN1 基因在mRNA和蛋白水平的表达,MTT法和流式细胞术检测A549细胞增殖和细胞周期分布。将稳定沉默 PIN1 的A549细胞与对照细胞皮下接种裸鼠,观察接种后肿瘤生长情况。 结果: 成功构建了pGPU6-GFP-Neo-PIN1载体,转染A549细胞并筛选获得稳定克隆。稳定转染pGPU6-GFP-Neo-PIN1的A549细胞中 PIN1 mRNA表达量较pGPU6-GFP-Neo转染组下降了893%;蛋白表达同时也显著抑制。 PIN1 基因沉默组的A549细胞增殖速率明显下降（P<0.01）,细胞出现G1期阻滞。小鼠体内实验显示, PIN1 沉默的A549细胞在裸鼠体内成瘤能力降低（P<0.01)。结论: pGPU6-GFP-Neo-PIN1质粒稳定转染肺癌A549细胞能有效沉默 PIN1 基因的表达,从而抑制A549细胞的增殖、影响细胞周期和抑制成瘤能力。     

基底样乳腺癌和管腔A 乳腺癌干祖细胞的生物学行为比较*

目的:从人基底样和管腔A 乳腺癌分离肿瘤干/祖细胞,并比较其增殖、自我更新和分化能力等生物学特点。方法:应用乳腺微球无血清悬浮培养法富集乳腺癌干/祖细胞,并通过细胞生长曲线测定和连续克隆形成实验检测了干/祖细胞在体外的增殖能力和自我更新能力,建立裸鼠移植瘤检测在体内的成瘤情况,流式细胞术检测CD44和CD24的表达水平。结果:基底样和管腔A 乳腺癌均能在无血清培养基中形成乳腺微球,基底样癌的肿瘤干细胞含量较高,并形成细胞数量多、直径大的微球,球内细胞在体内、外有更强的扩增能力。基底样癌传代过程中,细胞容易贴壁分化,传代多不超过15代;而管腔A 癌,虽然丧失克隆形成能力的悬浮单细胞明显增多,但均可传代20次以上;两者CD44和CD24的表达也有明显差异。结论:基底样乳腺癌和管腔A 乳腺癌的干/祖细胞表现出差别明显的生物学行为,乳腺癌的肿瘤干细胞可能是异质性的。      

长程多柔比星化疗富集乳腺肿瘤干细胞

目的:探讨长程多柔比星( adriamycin,ADR)作用乳腺癌细胞株MCF-7对富集肿瘤干细胞的可能性.方法:采用长程ADR诱导的方法建立ADR耐药细胞株MCF-7/ADR'.ALDEFLUOR法检测亲本MCF-7细胞及ADR耐药细胞MCF-7/ADR'中乙醛脱氢酶1(aldehyde dehydrogenase 1,ALDH1)阳性的肿瘤干细胞亚群的比例,然后采用无血清悬浮培养和裸鼠成瘤实验分别检测两者在体外形成干细胞微球体和体内成瘤能力的差异.结果:MCF-7和MCF-7/ADR'细胞中ALDH1+肿瘤干细胞亚群的比例分别为(0.82±0.77)％和(8.21±2.38)％,两者差异有统计学意义(P＜0.05);两者经无血清悬浮培养形成干细胞微球体的比例分别为(2.17±0.70)％和(7.87±1.39)％,差异有统计学意义(P＜0.05).MCF-7/ADR'细胞在裸鼠体内的成瘤能力明显强于MCF-7细胞.结论:长程ADR作用MCF-7后可富集肿瘤干细胞.     

下调ZEB-1表达对非小细胞肺癌A549细胞增殖、迁移与侵袭的影响

目的:探讨ZEB-1对非小细胞肺癌细胞株A549生物学行为的影响。方法:构建干扰ZEB-1的质粒,转染至A548细胞株,运用体外增殖、迁移、侵袭实验来观察ZEB-1表达下调后对非小细胞肺癌细胞株A549生物学行为的影响。结果:下调ZEB-1的表达可降低A549细胞株的增殖、迁移和侵袭能力。结论:ZEB-1表达水平与非小细胞肺癌侵袭转移的能力显著相关。     

ALDH-positive lung cancer stem cells confer resistance to epidermal growth factor receptor tyrosine kinase inhibitors

Molecular targeting therapeutics, such as EGFR tyrosine kinase inhibitors (TKIs), are important treatment strategies for lung cancer. Currently, the major challenge confronting targeted cancer therapies is the development of resistance. Cancer stem cells (CSCs) represent a rare population of undifferentiated tumorigenic cells responsible for tumor initiation, maintenance and spreading. Resistance to conventional chemotherapeutic drugs is a common characteristic of CSCs. However, the issue of whether CSCs contribute to EGFR TKI resistance in lung cancer is yet to be established. In the current study, we explored the association of ALDH1A1 expression with EGFR TKI resistance in lung cancer stem cells. ALDH1A1-positive lung cancer cells displayed resistance to gefitinib, compared to ALDH1A1-negative lung cancer cells. Moreover, PC9/gef cells (gefitinib-resistant lung cancer cells) presented a higher proportion of ALDH1A1-positive cells, compared to PC9 cells (gefitinib-sensitive lung cancer cells). Clinical sample studies were consistent with results from cell culture model systems showing that lung cancer cells with resistance to EGFR TKI and chemotherapy drugs contain significantly increased proportions of ALDH1A1-positive cells. These findings collectively suggest that ALDH1A1 positivity in cancer stem cells confers resistance to EGFR TKI in lung cancer.     

Expression and functional role of ALDH1 in cervical carcinoma cells

Tumor formation and growth is dictated by a very small number of tumor cells, called cancer stem cells, which are capable of self-renewal. The genesis of cancer stem cells and their resistance to conventional chemotherapy and radiotherapy via mechanisms such as multidrug resistance, quiescence, enhanced DNA repair abilities and anti-apoptotic mechanisms, make it imperative to develop methods to identify and use these cells as diagnostic or therapeutic targets. Aldehyde dehydrogenase 1 (ALDH1) is used as a cancer stem cell marker. In this study, we evaluated ALDH1 expression in CaSki, HeLa and SiHa cervical cancer cells using the Aldefluor method to isolate ALDH1-positive cells. We showed that higher ALDH1 expression correlated with significantly higher rates of cell proliferation, microsphere formation and migration. We also could demonstrate that SiHa-ALDH1- positive cells were significantly more tumorigenic compared to SiHa-ALDH1-negative cells. Similarly, SiHa cells overexpressing ALDH1 were significantly more tumorigenic and showed higher rates of cell proliferation and migration compared to SiHa cells where ALDH1 expression was knocked down using a lentivirus vector. Our data suggested that ALDH1 is a marker of cervical cancer stem cells and expand our understanding of its functional role.     

姜黄素调控Notch信号通路对肺癌干细胞增殖及凋亡的影响

目的:研究姜黄素对肺癌干细胞增殖及凋亡的影响。方法:利用免疫磁珠标记肺癌表面标记物乙醛脱氢酶1(ALDH1)，从肺癌A549细胞系中分离肺癌干细胞；MTT实验检测姜黄素对肺癌干细胞增殖的影响；流式细胞仪检测姜黄素对肺癌干细胞凋亡的影响；Western blot检测Notch1和Hes1蛋白的表达情况；抑制剂γ-分泌酶抑制Notch信号通路研究对肺癌干细胞增殖及凋亡的影响。结果:利用免疫磁珠分选法分选出肺癌细胞系A549中ALDH1+肺癌干细胞。MTT检测结果显示，姜黄素能够呈浓度依赖性的抑制肺癌干细胞的增殖；经姜黄素处理后的肺癌干细胞，与对照组相比，凋亡率明显升高，Notch1和Hes1蛋白的表达明显下降。经γ-分泌酶抑制剂处理肺癌干细胞后，实验结果显示，γ-分泌酶抑制剂通过下调Notch1和Hes1蛋白的表达调控Notch信号通路抑制肺癌干细胞的增殖，诱导其凋亡。结论:姜黄素抑制肺癌干细胞的增殖，诱导其凋亡与Notch信号通路有关。     

Both CD133+ and CD133− subpopulations of A549 and H446 cells contain cancer-initiating cells

Tumors have been known to contain a small population of cancer stem cells that initiate tumor growth and promote tumor spreading. CD133 alone or in combination with other markers is currently being used for identification and isolation of the putative cancer stem cell population from malignant tumors. To determine whether the CD133⁺ cells constitute the stem cell populations of lung cancer cells A549 and H446, CD133⁺ and CD133⁻ subpopulations were sorted from A549 and H446 cells by magnetic cell separation and characterized for their in vitro stem cell-like properties. Interestingly, both the CD133⁺ and CD133⁻ cells displayed similar abilities of colony formation, self-renewal, proliferation, differentiation, and invasion, as well as resistance to chemotherapy drugs. Furthermore, colony formation assays showed that more than 40% of cells in both the CD133⁺ cells and CD133⁻ subpopulations could form large colonies capable of regenerating the unsorted populations and forming tumors in nude mice. These results suggest that CD133 alone cannot be used as a stem cell marker for the lung cancer cells A549 and H446, and both the CD133⁺ and CD133⁻ subpopulations contain similar numbers of cancer stem cells. ( Cancer Sci 2009; 100: 1040–1046)     

肺癌细胞A549线粒体的动态分布与侵袭性和趋化性的关系

目的 初步探讨肿瘤细胞内线粒体动态分布的极性变化与肿瘤细胞侵袭和趋化性之间的关系.方法 将表达CXCR4受体的含有线粒体DNA( mitochondrial DNA,mtDNA)的肺腺癌A549细胞和缺乏mtDNA的ρ° A549细胞常规培养,施加趋化因子CXCL12刺激,利用Transwell技术检测趋化前后A549和ρ°A549的侵袭性和趋化性改变.另外,以MitoTracker标志线粒体,Hoechst标志核,利用荧光倒置显微镜观测CXCL12处理前后线粒体在细胞内的动态分布的极性变化.结果 对于A549( mtDNA+)肿瘤细胞,CXCL12处理后细胞迁移力明显高于CXCL12处理前细胞穿透数(P＜0.05),但CXCL12不能增强ρ° A549(mtDNA-)的侵袭性和趋化性.CXCL12处理前就已经有部分A549细胞内线粒体分布呈极性改变(0.25±0.05),但在CXCL12处理后这种呈极性改变的细胞比例明显增多(0.76±0.14,P＜0.05).结论 肿瘤细胞的侵袭和趋化性可能与线粒体在肿瘤细胞内的动态分布的极性变化有关.     

Liposarcoma Cells with Aldefluor and CD133 Activity have a Cancer Stem Cell Potential

ABSTRACT: Aldehyde dehydrogenase (ALDH) has recently been shown to be a marker of cancer stem-like cells (CSCs) across tumour types. The primary goals of this study were to investigate whether ALDH is expressed in liposarcomas, and whether CSCs can be identified in the ALDHhigh subpopulation. We have demonstrated that ALDH is indeed expressed in 10 out of 10 liposarcoma patient samples. Using a liposarcoma xenograft model, we have identified a small population of cells with an inducible stem cell potential, expressing both ALDH and CD133 following culturing in stem cell medium. This potential CSC population, which makes up for 0,1-1,7 % of the cells, displayed increased self-renewing abilities and increased tumourigenicity, giving tumours in vivo from as few as 100 injected cells.