共查询到19条相似文献,搜索用时 62 毫秒
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成体干细胞的可塑性:横向分化还是细胞融合? 总被引:1,自引:0,他引:1
近年来研究显示成体干细胞(adult stem cells)具有可塑性(plasticity),不仅可以生成它们所在组织的成熟细胞,而且在特定环境下能分化成其他组织类型细胞,这种跨系或跨胚层分化现象称为横向分化或转分化(transdifferentiation)。横向分化已为成体干细胞的研究和临床应用包括组织器官损伤的修复提供了新的思路和应用前景。然而,最近的一些研究进展又引出不同的解释,即成体干细胞的可塑性是由于细胞融合(cellfusion)的结果。在此,就成体干细胞的可塑性、横向分化、细胞融合等方面研究作一综述。 相似文献
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自从1998年第一次从内细胞团分离到人的胚胎干细胞,人们很快认识到胚胎干细胞在再生医学中的潜在应用价值。人们相信干细胞的研究将带来临床治疗各种疾病的革命。随着科学的进展,人们从胎儿和出生后个体的不同组织中分离到具有自我 相似文献
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对肝干细胞的可塑性、多向分化潜能、分化机理及其与肝癌发病机制的关系等方面进行综述.肝干细胞是一类具有自我更新能力和多向分化潜能的细胞. 在不同的条件下,肝干细胞可分化为肝细胞、胆上皮细胞、胰腺细胞和肠上皮细胞. 肝干细胞的分化涉及微环境、细胞因子和细胞外基质等多种调控因素. 肝干细胞分化为成熟肝细胞受多种转录因子和信号通路的调节,其分化异常有可能诱发形成肝细胞癌. 相似文献
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肌源干细胞可塑性研究进展 总被引:1,自引:0,他引:1
目前已证实肌肉中至少存在两种干细胞:肌卫星细胞和肌源干细胞。肌源干细胞被认为是卫星细胞的前体细胞,具有较高的增殖能力、更好的细胞生存能力和更宽的分化能力。肌源干细胞不仅能够分化成血、肌肉、脂肪、骨、软骨、内皮等中胚层细胞,而且也能打破胚层限制分化成外胚层和内胚层细胞。文章对肌源干细胞的分离纯化、鉴定、可塑性及临床应用做一综述。 相似文献
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成体干细胞可塑性的事实、质疑和展望 总被引:1,自引:0,他引:1
成体干细胞的可塑性是指存在于成年组织或器官中的不成熟细胞跨胚层分化的一种能力。近年来相关研究很多,有人认为成体干细胞具有可塑性,如造血干细胞可以分化为神经外胚层细胞和内胚层细胞:有人对其持怀疑态度,认为成年造血干细胞发育可塑性证据不足,成体干细胞不能跨胚层分化。由于分离纯化、检测手段等的局限,大多数研究均存在这样或那样的不足和误区,彻底研究清楚还有很长的路要走。 相似文献
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目前,癌症是导致人类死亡的主要因素之一。尽管在癌症治疗方面取得了巨大进展,但是,其较高的复发率还是会导致死亡。连续治疗失败的一个可能原因是,残留的恶性细胞有类似干细胞的分化潜能,这样就能再次形成肿瘤和造成病灶转移。肿瘤干细胞(cancer stem cell,CSC)假说认为,肿瘤组织中存在具有自我跟新能力,无限增殖和肿瘤形成能力的一小部分肿瘤细胞,近年来,随着在血液肿瘤和实体瘤中相继发现CSC存在的相关证据,对CSC的生物学特性的认识不断深入,对肿瘤的复发、病灶转移、耐药性形成也有了新的观点和研究方向,目前的研究主要集中在其分离鉴定阶段,本文就近年来该方面的研究进展作一综述。 相似文献
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肿瘤组织中存在一小群能够自我更新、增殖和分化,对肿瘤的发生、发展、复发、转移起决定作用的细胞,即肿瘤干细胞(cancer stem cells,CSCs)。在传统理论方法已不能攻克癌症的情况下,肿瘤干细胞理论为我们重新认识肿瘤的起源和本质提供了新的方向和视角。从20世纪50年代至今,随着生物技术的发展,肿瘤干细胞理论经历了从设想到验证的漫长历程。但该理论自提出之日起便受到来自各方面不同观点的质疑。当今针对肿瘤干细胞癌症治疗主要集中在靶向问题上。因此,寻找特异的肿瘤干细胞标志物,探索肿瘤干细胞与周围微环境间的复杂关系以及发现调控其功能的关键信号通路成为当前研究的热点。 相似文献
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Issues in stem cell plasticity 总被引:7,自引:0,他引:7
Experimental biology and medicine work with stem cells more than twenty years. The method discovered for in vitro culture of human embryonal stem cells acquired at abortions or from?surplus” embryos left from in vitro fertilization, evoked immediately ideas on the posibility to aim development and differentiation of these cells at regeneration of damaged tissues. Recently, several surprising observations proved that even tissue‐specific (multipotent) stem cells are capable, under suitable conditions of producing a while spectrum of cell types, regardless, whether these tissues are derived from the same germ layer or not. This ability is frequently called stem cell plasticity but other authors also use different names ‐?non‐orthodox differentiation” or?transdifferentiation”. In this paper we wish to raise several important questions and problems related to this theme. Let us remind some of them: Is it possible to force cells of one‐type tissue to lool and act as cells of another tissue? Are these changes netural? Could these trans‐formations be used to treat diseases? What about the bioethic issue? However, the most serious task “still remains to be soloved ‐ how to detect, harvestand culture stem cells for therapy of certain diseases”. 相似文献
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Marina Carla Cabrera Robert E Hollingsworth Elaine M Hurt 《World journal of stem cells》2015,7(1):27-36
The origins of the complex process of intratumoral heterogeneity have been highly debated and different cellular mechanisms have been hypothesized to account for the diversity within a tumor. The clonal evolution and cancer stem cell(CSC) models have been proposed as drivers of this heterogeneity. However, the concept of cancer stem cell plasticity and bidirectional conversion between stem and non-stem cells has added additional complexity to these highly studied paradigms and may help explain the tumor heterogeneity observed in solid tumors. The process of cancer stem cell plasticity in which cancer cel s harbor the dynamic ability of shifting from a non-CSC state to a CSC state and vice versa may be modulated by specific microenvironmental signals and cellular interactions arising in the tumor niche. In addition to promoting CSC plasticity, these interactions may contribute to the cellular transformation of tumor cells and affect response to chemotherapeutic and radiation treatments by providing CSCs protection from these agents. Herein, we review the literature in support of this dynamic CSC state, discuss the effectors of plasticity, and examine their role in the development and treatment of cancer. 相似文献
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Dean G Tang 《Cell research》2012,22(3):457-472
Heterogeneity is an omnipresent feature of mammalian cells in vitro and in vivo. It has been recently realized that even mouse and human embryonic stem cells under the best culture conditions are heterogeneous containing pluripotent as well as partially committed cells. Somatic stem cells in adult organs are also heterogeneous, containing many subpopulations of self-renewing cells with distinct regenerative capacity. The differentiated progeny of adult stem cells also retain significant developmental plasticity that can be induced by a wide variety of experimental approaches. Like normal stem cells, recent data suggest that cancer stem cells (CSCs) similarly display significant phenotypic and functional heterogeneity, and that the CSC progeny can manifest diverse plasticity. Here, I discuss CSC heterogeneity and plasticity in the context of tumor development and progression, and by comparing with normal stem cell development. Appreciation of cancer cell plasticity entails a revision to the earlier concept that only the tumorigenic subset in the tumor needs to be targeted. By understanding the interrelationship between CSCs and their differentiated progeny, we can hope to develop better therapeutic regimens that can prevent the emergence of tumor cell variants that are able to found a new tumor and distant metastases. 相似文献