慢性粒细胞白血病肿瘤干细胞的免疫功能

背景:研究认为间充质干细胞可能是骨髓造血微环境的免疫保护位点。由于慢性粒细胞白血病存在造血微环境异常和免疫异常,所以推测间充质干细胞可能在慢性粒细胞白血病的病理过程中扮演了一个重要角色。目的:观察慢性粒细胞白血病骨髓来源的肿瘤干细胞的免疫学特征,比较其与正常人来源的间充质干细胞是否存在免疫功能的异常。方法:分离正常人和慢性粒细胞白血病患者的骨髓间充质干细胞,分别检测它们对T细胞周期、活化、抑制和增殖的作用。结果与结论:慢性粒细胞白血病和正常志愿者骨髓来源的间充质干细胞形态和表型没有差异,慢性粒细胞白血病患者来源的间充质干细胞抑制T细胞增殖的作用减弱,抑制T细胞周期及活化的能力减弱,慢性粒细胞白血病患者抑制T细胞凋亡的作用增强。提示慢性粒细胞白血病患者骨髓来源的间充质干细胞存在明显的免疫调节功能缺陷,如果使用慢性粒细胞白血病患者自体的间充质干细胞移植治疗可能不是一种很好的选择,对于骨髓增生异常综合征患者最好是选用异基因的间充质干细胞移植。     

慢性粒细胞白血病肿瘤干细胞的免疫功能

背景：研究认为间充质干细胞可能是骨髓造血微环境的免疫保护位点。由于慢性粒细胞白血病存在造血微环境异常和免疫异常,所以推测间充质干细胞可能在慢性粒细胞白血病的病理过程中扮演了一个重要角色。目的：观察慢性粒细胞白血病骨髓来源的肿瘤干细胞的免疫学特征,比较其与正常人来源的间充质干细胞是否存在免疫功能的异常。方法：分离正常人和慢性粒细胞白血病患者的骨髓间充质干细胞,分别检测它们对T细胞周期、活化、抑制和增殖的作用。结果与结论：慢性粒细胞白血病和正常志愿者骨髓来源的间充质干细胞形态和表型没有差异,慢性粒细胞白血病患者来源的间充质干细胞抑制T细胞增殖的作用减弱,抑制T细胞周期及活化的能力减弱,慢性粒细胞白血病患者抑制T细胞凋亡的作用增强。提示慢性粒细胞白血病患者骨髓来源的间充质干细胞存在明显的免疫调节功能缺陷,如果使用慢性粒细胞白血病患者自体的间充质干细胞移植治疗可能不是一种很好的选择,对于骨髓增生异常综合征患者最好是选用异基因的间充质干细胞移植。     

基质金属蛋白酶9在慢性粒细胞白血病患者骨髓间充质干细胞中表达及其对造血干细胞黏附的影响

背景:骨髓微环境中持续存在的肿瘤干细胞改变了骨髓基质细胞及细胞外基质的特征,从而参与了造血干细胞恶性转化的过程.目的:探讨慢性粒细胞白血病患者骨髓间充质干细胞基质金属蛋白酶9的表达,及其对造血干细胞黏附的影响.设计、时间及地点:细胞学体外对照观察,于2007-09/2008-02在北京协和医学院基础学院完成.材料:骨髓标本来源于4例慢性粒细胞白血病患者和4例健康志愿者,由解放军第三○九医院血液科提供.脐血由北京脐带血造血干细胞库提供,293T细胞由南开大学孔德领教授馈赠.方法:分别采集健康志愿者和慢性粒细胞白血病患者的骨髓,Ficoll法体外分离培养获得骨髓间充质干细胞.将脐血分装,离心弃上清,吸取中河层,同法分离培养获得脐血单个核细胞.取处于对数生长期的骨髓间充质干细胞,按1×107L-1接种于96孔板,培养至近100%融合时再将脐血单个核细胞按1×105/孔接种于同一培养板中,孵育1 h后对收集未黏附细胞,计算黏附率.取第2代骨髓间充质干细胞,ELISA法检测细胞培养上清中可溶性形式细胞问黏附分子1的质量浓度.构建MPP-9-siRNA干扰载体,以脂质体法转染包装293T细胞,扩增病毒后进行骨髓间充质干细胞转染.主要观察指标:健康供者与慢性粒细胞白血病患者之间的5项指标比较,病毒转染前后慢性粒细胞白血病患者自身的3项指标比较.结果:与健康供者比较,慢性粒细胞白血病患者骨髓间充质干细胞基质金属蛋白酶9 mRNA及蛋白表达水平明显升高,细胞间黏附分子1的蛋白表达无明显差异,培养上清中可溶性形式细胞间黏附分子1的质量浓度明显升高(P＜0.05),对脐血单个核细胞的黏附率明显降低(P＜0.05).与未转染的骨髓间充质干细胞比较,病毒转染后骨髓间充质干细胞基质金属蛋白酶9mRNA表达明显降低,细胞间黏附分子1的蛋白表达未受影响,对脐血单个核细胞的黏附率明显增加(P＜0.05).结论:慢性粒细胞自血病患者的骨髓间充质干细胞可能存在基质金属蛋白酶9裂解细胞间黏附分子1的作用机制,推测游离的可溶性形式细胞间黏附分子1可能阻断了LFA-1的结合位点,从而影响骨髓间充质干细胞对造血干细胞的黏附.     

低氧对间充质干细胞生物学特性的影响

间充质干细胞是细胞组织工程、细胞替代治疗、基因治疗及移植领域的研究热点.最近研究表明,氧体积分数的变化将影响间充质干细胞的许多生物学特性,在不同氧体积分数下间充质干细胞具有不同增殖凋亡、分化及迁移趋化能力.低氧是一种常见的病理生理状态,适度低氧可促进间充质干细胞增殖及凋亡,有利于迁移和趋化,其对分化的影响因细胞类型不同而有所差异.低氧影响间充质干细胞的分子机制主要涉及低氧诱导因子1、趋化因子及其受体、基质金属蛋白酶.低氧可活化低氧诱导因子1信号通路,该通路的活化上调基质衍生因子1的表达,并形成适合干细胞存在及生长的微环境,通过基质衍生因子1促进趋化因子受体CXCR4阳性的干细胞黏附、迁移和归巢到低氧部位:同时可通过调节基质金属蛋白酶的表达和基质金属蛋白分泌来促进细胞外基质降解,进而使间充质干细胞迁移能力增强.     

体外培养慢性粒细胞白血病患者骨髓间充质干细胞的生物学特性

背景:课题组从胎儿骨髓间充质干细胞的培养体系中鉴定出一类贴壁细胞,已证实此类细胞在单细胞水平可以向造血及内皮细胞分化.目的:检测骨髓间充质干细胞的生物学特性,为慢性粒细胞白血病的治疗提供相关的依据.方法:以慢性粒细胞白血病患者骨髓为研究对象,体外培养并扩增原始间充质干细胞,检测其BCR/ABL融合基因的表达、免疫学特性和生长曲线,使用RT-PCR和FISH的方法检测其BCR/ABL融合基因的表达情况.结果与结论:慢性粒细胞白血病患者骨髓来源的间充质干细胞呈成纤维样生长,大部分细胞处于G0/G1期,并且高表达Flk1,CD13,CD29,CD44,用RT-PCR和FISH的方法能够检测出BCR/ABL融合基因的表达.提示慢性粒细胞白血病的白血病基因转化可能发生在比造血干细胞更高的骨髓间充质干细胞水平上,对慢性粒细胞白血病的疾病起源及干细胞移植治疗有重要的意义.     

骨髓间充质干细胞对造血干细胞移植免疫的影响及其机理

骨髓间充质干细胞具有自我更新及多向分化的潜能,在骨髓中合成分泌多种细胞因子,并通过细胞间相互作用为造血干细胞的分裂、增殖与分化提供良好的微环境.有研究显示,骨髓间充质干细胞能够促进异基因造血干细胞植入,并在一定程度上减轻移植物抗宿主病的作用.这种对移植免疫的影响可能与其保护MHC相合造血干细胞逃脱抗原识别,抑制非特异性淋巴细胞活化增殖有关.本文对骨髓间充质干细胞特性、骨髓间充质干细胞影响移植免疫的表现、骨髓间充质干细胞影响移植免疫的机理进行了综述.     

体外培养慢性粒细胞白血病患者骨髓间充质干细胞的生物学特性

背景：课题组从胎儿骨髓间充质干细胞的培养体系中鉴定出一类贴壁细胞,已证实此类细胞在单细胞水平可以向造血及内皮细胞分化。目的：检测骨髓间充质干细胞的生物学特性,为慢性粒细胞白血病的治疗提供相关的依据。方法：以慢性粒细胞白血病患者骨髓为研究对象,体外培养并扩增原始间充质干细胞,检测其BCR/ABL融合基因的表达、免疫学特性和生长曲线,使用RT-PCR和FISH的方法检测其BCR/ABL融合基因的表达情况。结果与结论：慢性粒细胞白血病患者骨髓来源的间充质干细胞呈成纤维样生长,大部分细胞处于G0/G1期,并且高表达Flk1,CD13,CD29,CD44,用RT-PCR和FISH的方法能够检测出BCR/ABL融合基因的表达。提示慢性粒细胞白血病的白血病基因转化可能发生在比造血干细胞更高的骨髓间充质干细胞水平上,对慢性粒细胞白血病的疾病起源及干细胞移植治疗有重要的意义。     

小鼠骨髓间充质干细胞对胚胎干细胞造血分化的影响

骨髓间充质干细胞作为骨髓基质细胞的前体细胞 ,在体外具有一定的造血支持作用 ,与造血干细胞共移植可促进其植入。本研究旨在初步探讨应用小鼠骨髓间充质干细胞与胚胎干细胞共培养作为一种新的分化体系的可行性。首先分离、培养并鉴定小鼠骨髓间充质干细胞 ,然后利用扩增培养的骨髓间充质干细胞与胚胎干细胞共培养 ,通过造血集落培养和RT PCR观察造血分化的特点。结果表明 ,分离、扩增培养至第四代之后的骨髓间充质干细胞形态均一 ,高表达Sca 1,CD2 9,CD4 4和CD10 5 ,而CD34和CD4 5等造血与内皮细胞特异性表面标志呈阴性 ;特异性诱导体系内传代后 (>4代 )的骨髓间充质干细胞可向脂肪细胞和成骨细胞分化。与悬浮分化体系相比 ,骨髓间充质干细胞共培养体系中初始分化的胚胎干细胞含有显著增加的拟胚体形成细胞而没有造血集落形成细胞。此外 ,RT PCR检测发现 :共培养细胞表达胚胎干细胞特异性转录因子Oct 4 ,而造血标记Flk 1,GATA 1和 β H1为阴性。结论 :间充质干细胞在一定程度上抑制了胚胎干细胞的初始分化 ,但是共培养体系来源的拟胚体产生造血集落的能力显著高于悬浮体系     

慢性粒细胞白血病患者骨髓间充质干细胞形态学的实验研究

目的：慢性粒细胞白血病患者骨髓间充质干细胞形态学实验观察。方法：将慢性粒细胞白血病患者的骨髓间充质干细胞，自骨髓经密度梯度离心分离、纯化和培养，观察原代和传代细胞的细胞形态。结果：原代培养的骨髓间充质干细胞最佳的的贴壁时间为3d，生长性状不一，散在圆形细胞群、树枝状细胞群、飞燕状细胞群、火焰状细胞群。结论：体外非诱导培养的骨髓间充质干细胞方法可能为临床治疗慢性粒细胞性白血病患者进行异基因骨髓移植后抑制移植物抗宿主病反应提供物质基础。     

间充质干细胞对T细胞免疫调节作用的研究进展

间充质干细胞(MSC)是备受关注的一类成体干细胞,具有高度自我更新及多向分化潜能.MSC可通过分泌细胞因子及细胞外基质维持骨髓造血微环境的稳定,同时,可通过多种途径调节活化的淋巴细胞,但其机制尚不十分明确.     

神经干细胞与脑胶质瘤干细胞

所有的肿瘤组织并不是由均一的肿瘤细胞所组成的,不同的细胞具有不同的增殖、浸润和转移能力,亦即肿瘤的异质性.其中存在少数担当着干细胞角色的肿瘤细胞,具有干细胞的基本特性,包括自我更新能力、无限的增殖能力和多向分化潜能,为肿瘤干细胞.神经干细胞具有很强的自我更新机制,获得较少突变即有可能恶性转化,而且干细胞存活时间较长,这意味着干细胞比成熟细胞发生细胞复制的错误几率更大.因外界环境的刺激而发生突变的机会更多,最终形成脑胶质瘤干细胞,同时调节神经干细胞增殖和自我更新的基因在脑胶质瘤的脑胶质瘤干细胞中也表达,这也是支持神经干细胞是脑胶质瘤干细胞来源的;也有推测认为它可能起源于已分化的细胞,由这些细胞突变发生去分化得来,并通过基因突变而获得了干细胞自我更新的特性,从而形成脑胶质瘤干细胞.通过探讨神经干细胞与脑胶质瘤干细胞,为脑胶质瘤的治疗提供依据.     

Hematopoietic stem cells and mature blood cells from pluripotent stem cells

Pluripotent stem cells such as embryonic stem cells and induced pluripotent stem cells could be good sources for obtaining massive hematopoietic stem cells (HSC) and mature blood cells. Coculture with feeder cells and embryoid body formation are two major strategies to induce hematopoietic differentiation from pluripotent stem cells. Derivation of HSC with ability of reconstituting human hematopoiesis in immunodeficient mice has been achieved. It is also possible to generate mature blood cells such as neutrophils, erythrocytes, and platelets from pluripotent stem cells. Their morphologies, phenotypes, and functions are usually very similar to those of normal counterparts. However, a breakthrough is needed to overcome the issue of "yield", which still stands as a high barrier to reach clinical applications.     

表皮干细胞与毛囊干细胞生物学特性的比较

背景:获取更合适的组织工程皮肤种子细胞可使皮肤功能得到更好的修复。目的:分离、培养表皮干细胞和毛囊干细胞,并比较两种细胞的生物学特性。方法:体外分离培养2月龄新西兰兔表皮干细胞和毛囊干细胞,取生长良好的第2,3,6代细胞观察其生物学特性。结果与结论:毛囊干细胞较表皮干细胞贴壁快,具有更高的增殖活性。免疫组化及荧光定量PCR检测显示毛囊干细胞β1整合素、角蛋白19蛋白及mRNA表达均明显高于表皮干细胞。提示作为皮肤组织工程的种子细胞,毛囊干细胞较表皮干细胞更具优势。     

Muscle-derived stem cells

The existence of cells with stem cell-like abilities derived from various tissues can now be extended to include the skeletal muscle compartment. Although researchers have focused on the utilization of these cells with regard to their myogenic capacity, initially exploring more efficient cellular therapy treatments for muscular dystrophy, it is becoming increasingly apparent that such cells may one day be used in the treatment of non-myogenic disorders. Evidence regarding the existence and differentiation capacity of muscle-derived stem cells is discussed, along with current theories regarding their proposed position within the myogenic hierarchy.     

Mesenchymal stem cells

About 40 years ago Friedenstein described stromal cells in the bone marrow that were spindle shaped and proliferate to form colonies. These cells attach to plastic and are able to differentiate under defined in vitro conditions into multiple cell types present in many different tissues, e.g. osteoblasts, chondroblasts, adipocytes, etc. Later on these cells, obtained from postnatal bone marrow, were called mesenchymal stem cells (MSC) or stromal stem cells. Recently the presence of somewhat similar cells has been demonstrated in many other tissues too. In spite of extensive attempts to characterize these cells we are still lacking definitive in vivo markers of MSC although retrospective functional data strongly support the existence of common adult stem cells that have the capacity to differentiate along various specific differentiation lineages. Since MSC can be rather easily isolated from the bone marrow and can also be expanded in vitro they have become a prime target for researchers of tissue regeneration. These cells have now been extensively used for transplantation experiments in animals and also for some therapeutic trials in humans. However, much new research is needed to learn enough on the molecular mechanisms of MSC differentiation to evaluate their full capacity for tissue regeneration.     

Cancer stem cells

The cancer stem cell (CSC) hypothesis has had a major effect on the fields of cancer cell biology and clinical oncology. CSCs were originally described in hematologic malignancies, and subsequently in a variety of solid tumors. Their unique biological characteristics, including self-renewal capability, stem cell signaling pathways, relative quiescence and resistance to standard chemotherapy and radiotherapy are providing researchers and clinicians with new challenges. One important outcome of this new perspective on tumors is the recognition that effective treatment approaches will need to target both the rapidly proliferating bulk tumor cells, and the quiescent CSCs, which contain the ability to reestablish the malignancy when treatment is withdrawn. The clinical laboratory will undoubtedly see an influx of new molecular and histopathological tests to augment initial diagnosis, treatment decisions, and prognostic monitoring of cancer patients related to identifying and quantifying these as CSCs.     

Leukaemic stem cells

All haemopoietic cell lineages arise from multipotential self-renewing stem cells that give rise to committed progenitor cells. These progenitor cells subsequently differentiate into more lineage-committed cells with a restricted range of plasticity. A hierarchical order is considered to exist, where lineage commitment and differentiation are thought to be irreversible. As cells differentiate, they gradually lose the ability to self-renew. The most primitive haemopoietic progenitor cells have the ability to reconstitute long-term haemopoiesis in myeloablated recipients. However, as cells differentiate, there is an orchestrated silencing of some genes and activation of others, resulting in lineage commitment and generally a reduction in proliferative ability. Here, we discuss potential differences between normal and leukaemic stem cells, some of which may have therapeutic implications.     

Mesenchymal stem cells

About 40 years ago Friedenstein described stromal cells in the bone marrow that were spindle shaped and proliferate to form colonies. These cells attach to plastic and are able to differentiate under defined in vitro conditions into multiple cell types present in many different tissues, e.g. osteoblasts, chondroblasts, adipocytes, etc. Later on these cells, obtained from postnatal bone marrow, were called mesenchymal stem cells (MSC) or stromal stem cells. Recently the presence of somewhat similar cells has been demonstrated in many other tissues too. In spite of extensive attempts to characterize these cells we are still lacking definitive in vivo markers of MSC although retrospective functional data strongly support the existence of common adult stem cells that have the capacity to differentiate along various specific differentiation lineages. Since MSC can be rather easily isolated from the bone marrow and can also be expanded in vitro they have become a prime target for researchers of tissue regeneration. These cells have now been extensively used for transplantation experiments in animals and also for some therapeutic trials in humans. However, much new research is needed to learn enough on the molecular mechanisms of MSC differentiation to evaluate their full capacity for tissue regeneration.     

肺干细胞、肺癌干细胞与肺癌

背景:随着肿瘤干细胞理论的出现,近年来通过杀死肿瘤干细胞而治疗肿瘤的研究逐渐兴起,并取得一定的进展。目的:综述肺干细胞、肺癌干细胞及肺癌的研究进展。方法:应用计算机检索中国全文期刊数据库及PubMed相关文献,检索词分别为"肺癌干细胞、肺癌、肺干细胞","lung stem cell,lung cancer stem cell,lungcancer,cancer stem cell",并限定语言为英语和中文,最终入选32篇文章进行综述。结果与结论:肺癌干细胞可能起源于正常肺组织干细胞,而肺癌干细胞可能是肺癌发生的重要因素。随着对肺癌干细胞研究的深入,肺癌治疗将会进入一个崭新的阶段。