肝癌干细胞的研究进展

肿瘤起源于干细胞的假说正在各种人类肿瘤中得到证实.肿瘤不仅是一种基因病,而且是一种干细胞病,基因突变作用于干细胞,干细胞突变成为肿瘤干细胞,这是肿瘤发生、再生、转移和复发的关键.为证实肝癌干细胞的存在,有两个问题必须提出:(1)肝细胞型肝癌是否来源于肝干细胞?(2)肝细胞型肝癌中是否具有干细胞特征的细胞?最新研究表明:肝细胞型肝癌可能是由肝干细胞未分化或分化不全引起的.对于肝癌细胞的研究我们知道肝细胞型肝癌中的细胞具有干细胞特性,如永生性、可移植性以及对治疗手段的抵抗性.但是,至今为止,确切的肝癌干细胞的标记物没有找到,而且没有分离出肝癌干细胞.     

肝干细胞与肝癌干细胞相关研究进展

肿瘤是一种干细胞疾病,这一理论目前得到广泛认可,越来越多的研究也显示了干细胞与肝癌发生间的密切关系。肝癌恶性程度高,疗效差,研究干细胞在肝癌中的作用有望从根本上改变肝癌的诊疗方法和疗效。本文就干细胞在肝癌中的相关研究进展作一综述。     

胃癌干细胞研究现状

肿瘤干细胞足肿瘤研究领域的新热点.肿瘤干细胞理论指m肿瘤可能是由肿瘤干细胞和微生态环境产生,而肿瘤千细胞则由正常干细胞突变而来.目前已经在多种肿瘤中发现并鉴定出肿瘤干细胞,包括白血病、乳腺癌、脑肿瘤、肝癌、结肠癌等.本文就胃癌干细胞的研究现状作一综述.     

肝癌干细胞的研究进展

肝癌是世界上最常见的第五大恶性肿瘤,第三大常见的癌症致死原因,研究者一直试图阐明肝癌的发生机制以及细胞起源。近年肿瘤干细胞理论备受人们关注,认为肿瘤可能是正常干细胞在长期自我更新过程中,细胞微环境、致癌剂和遗传因素相互作用于干细胞引起生长分化调控途径中某些分子发生遗传或表观遗传学改变,导致表达异常,进而引起细胞过度异常增殖。越来越多的研究结果支持肝癌起源于干细胞的观点,本文就肝癌干细胞的研究进展做一综述。     

肝癌干细胞的研究热点及前景

随着越来越多的肿瘤中发现肿瘤干细胞(cancer stem cells,CSCs)的存在,肝癌被认为很可能也是一种干细胞疾病。肝癌干细胞(liver cancer stem cells,LCSCs)若能最终得到确认,将会为肝癌的预防、早期诊断、有效治疗及预后监测等开辟一条崭新的途径。     

肝肿瘤干细胞的研究进展

肿瘤干细胞是一群存在于某些肿瘤组织中的干细胞样细胞。笔者就肝肿瘤干细胞的来源、与肝癌的关系、分离鉴别等问题的研究进展作一综述。     

肿瘤干细胞与骨肉瘤相关研究进展

肿瘤研究中发现极少数有分化潜能,可无限增殖的亚细胞群具有干细胞特性,肿瘤的发生、生长、转移与之密切相关.肿瘤干细胞主要来源于成体干细胞,也可来源于祖细胞、分化细胞或骨髓细胞.白血病、乳腺癌、恶性脑瘤存在肿瘤干细胞已经明确,在前列腺癌、肺腺癌、肝癌、恶性黑色素瘤等多种肿瘤中也已初步分离出相应的肿瘤干细胞.骨肉瘤是常见的骨组织恶性肿瘤,肿瘤干细胞学说可更好地解释骨肉瘤恶性程度高、转移早、抗化疗等特性.应用无血清悬浮培养方法,干细胞样骨肉瘤细胞已初步得以分离、分析.该文就肿瘤干细胞及干细胞样骨肉瘤细胞的相关研究进展作一综述.     

肝脏干细胞恶性转化的研究进展

越来越多的研究认为,包括肝癌在内的许多恶性肿瘤是干细胞来源的疾病,并且肝癌的发生、耐药、转移及复发与肿瘤内被称作肿瘤干细胞的一小群细胞密切相关.虽然对肝癌及肝癌干细胞的来源仍有争议,但通过近十多年的大量研究,很多学者认为肝癌及肝癌干细胞很有可能是由正常肝脏干细胞在各种致癌因素下发生恶性转化而来的.本文就正常肝脏干细胞恶性转化方面的相关研究进展进行综述.     

肝癌干细胞标志物研究的进展

肝癌是常见的恶性肿瘤,其目前的治疗手段是以手术为主的综合治疗,但是术后易复发、转移,预后较差。肿瘤干细胞学说认为只有杀灭肝癌干细胞才能从根本上治愈肝癌,因此分离和鉴定肝癌干细胞成为研究的热点。笔者就目前的肝癌干细胞表面标志物研究进展进行综述。     

肿瘤干细胞的研究进展

越来越多的研究认为肿瘤中存在肿瘤干细胞,肿瘤干细胞是肿瘤发生、发展、侵袭、转移及耐药的决定性因素,是目前肿瘤研究的新方向。尽管其研究尚处于起步阶段,但已显示出了广阔的前景。文中就肿瘤干细胞的基础要领及其在白血病、脑肿瘤、乳腺癌、肝癌等方面的研究进展进行综述。     

肿瘤干细胞对恶性肿瘤诊治的意义

恶性肿瘤严重地威胁着人类的健康.多药耐药现象增加了其治疗难度,局部复发和远处转移最终导致了治疗失败,然而遗憾的是机制尚不清楚.研究发现在肿瘤组织中有一个具有自我更新及分化潜能的的细胞亚群,是复发及转移的根源.这部分细胞被称为肿瘤干细胞.随后,人们相继从血液系统肿瘤及多种实体瘤中分离、鉴定了肿瘤干细胞.随着肿瘤干细胞学说的提出及确认,人们对肿瘤的复发、转移及多药耐药现象有了新的认识,从而为恶性肿瘤的治疗及复发转移的预防提供了一个全新的线索.本文就此进行综述.     

Role of stem cells in kidney repair

End-stage renal disease and acute renal failure are the most important issues of practical and clinical nephrology, bearing in mind their high mortality rate, solely symptomatic treatment, and overall economic impact on society. The advances in stem cell biology opened the door for the new era in treatment of many disorders, including renal, offering new therapeutical solutions. Findings suggesting that the adult kidney contains stem cells and that stem cells from bone marrow have potential to differentiate into renal cells focused research on the possible application of these cells in therapy of kidney disorders. The other promising candidates for stem cell therapy for the kidney are embryonic stem cells and amniotic fluid-derived stem cells. This article focuses on the characteristics and possible application of these types of stem cells.     

Investigations of prostate epithelial stem cells and prostate cancer stem cells

Although both prostate epithelial stem cells and prostate cancer stem cells are implicated in the differentiation of the normal prostate gland and carcinogenesis of prostate cancer, there has, until recently, been little information regarding their biology. This review summarizes the recent advancements in cell biological research including various in vitro culture systems that have offered the characterization and isolation of prostate epithelial stem cells and prostate cancer stem cells. In addition, the stromal niche or microenvironment of stem cells plays an essential role in proliferation and differentiation of normal stem cells. Stroma surrounding cancer cells, which also provide another unique niche, may involve the initiation and development of cancer stem cells. Investigation of stem cells and their microenvironments in the prostate should lead to the elucidation of biological features and the development of novel treatments for prostate cancer.     

Renal differentiation from adult spermatogonial stem cells

Abstract

There is considerable interest in the use of multi-potent stem cells in kidney tissue regeneration. We studied if spermatogonial stem cells have the ability to undergo kidney differentiation. Spermatogonial stem cell differentiation was induced using in vitro and ex vivo co-culture techniques. Conditioned media from human kidney fibroblasts induced the expression of epithelial and endothelial lineages in spermatogonial stem cells, consistent with nephrogenesis. Furthermore, we showed that these cells up-regulated renal tubular-specific markers alkaline phosphatase, mineralocorticoid receptor, renal epithelial sodium channel and sodium-glucose transporter-2 (p?<?0.05). GFP-labeled spermatogonial stem cells were engrafted into metanephric kidney organ cultures harvested from E12.5 mouse embryos. After 5 days of organ culture, focal anti-GFP staining was detectable in all inoculated kidneys demonstrating integration of spermatogonial stem cells into the developing kidney (p?<?0.01). Histological assessment showed early nephron-like architecture. In summary, we show that spermatogonial stem cells have the potential to generate renal tissue and lay the foundations for further investigations into a novel therapeutic approach for renal insufficiency.     

Immunosuppressive mechanisms of embryonic stem cells and mesenchymal stem cells in alloimmune response

Although both embryonic stem cells (ESCs) and mesenchymal stem cells (MSCs) are known to have immunosuppressive effects, the mechanisms of immunosuppression are still controversial. Both types of stem cells suppressed not only the proliferation but also survival of CD4⁺ T cells in vitro. They suppressed secretion of various cytokines (IL-2, IL-12, IFN-??, TNF-??, IL-4, IL-5, IL-1??, and IL-10), whereas there was no change in the levels of TGF-?? or IDO. Classic and modified transwell experiments demonstrated that immunosuppressive activities were mainly mediated by cell-to-cell contact. Granzyme B in the ESCs played a significant role in their immunosuppression, whereas PDL-1, Fas ligand, CD30 or perforin was not involved in the contact-dependent immunosuppression. However, none of the above molecules played a significant role in the immunosuppression by the MSCs. Interestingly, both stem cells increased the proportion of Foxp3⁺ regulatory T cells. Our results showed that both ESCs and MSCs suppressed the survival as well as the proliferation of T cells by mainly contact-dependent mechanisms and increased the proportion of regulatory T cells. Granzyme B was involved in immunosuppression by the ESCs in a perforin-independent manner.     

胃癌乳斑微转移在胃癌干细胞及前驱细胞研究中的意义

目的：探讨胃癌乳斑微转移模型在胃癌干细胞及前驱细胞研究中的意义。方法：胃癌细胞系MFC,1×10~4细胞数量注射到小鼠腹腔内,72 h后取大网膜,收集乳斑微转移灶内的胃癌细胞团;以不同细胞数量进行NOD/SCID小鼠皮下注射,观察细胞的致瘤能力,移植瘤HE染色,免疫组化分析CEA、CK20表达;免疫细胞化学分析乳斑微转移灶内的胃癌细胞团干细胞相关标志物的表达。结果：皮下注射16周后,微转移灶内的胃癌细胞团组中,皮下注射数量为5×10~2个细胞有1个部位产生肿瘤组织：注射数量为1×10~3个细胞时,5个部位均能产生肿瘤组织。对照组皮下注射为5×10~4个细胞时,仅1个部位出现肿瘤,而注射部位全部出现肿瘤组织,需要5×10~6个以上的细胞数量。两组皮下肿瘤组织分别经HE染色和免疫组化分析CEA、CK20表达,与对照组比较无统计学差异。微转移灶内细胞团高表达CD133和CD44,而CD324的表达则明显下降。结论：胃癌乳斑微转移模型内存在丰富的胃癌于细胞及前驱细胞;大网膜乳斑微环境具有富集胃癌干细胞及前驱细胞的作用。CD133~＋、CD44~＋和CD324~-可能是胃癌干细胞的表面标志物。     

Pre-transplant co-infusion of donor-adipose tissue derived mesenchymal stem cells and hematopoietic stem cells may help in achieving tolerance in living donor renal transplantation

Transplantation tolerance is still a Utopian dream for many transplanters. Mesenchymal stem cells (MSC) have shown immuno-modulatory and tolerogenic effects in experimental models. We present a 29-year-old male with end stage renal disease (ESRD) who was transplanted with HLA 4/6 matched kidney from 51-year-old father in June 2010 preceded by co-infusion of donor-adipose tissue derived mesenchymal stem cells (AD-MSC) and bone marrow derived hematopoietic stem cells (BM-HSC) under non-myeloablative conditioning for deleting rejecting T and B-cells. He has maintained fairly stable graft function with serum creatinine (SCr) between 1.5 and 1.8?mg/dL at 3 years post-transplant with absence of donor specific antibodies (DSA), normal protocol graft biopsy, and peripheral T-regulatory cell levels (pTregs) (CD127^low/?CD25^highCD4⁺) of 4.57% on zero immunosuppression since 6 months.     

神经干细胞与BMSCs移植治疗脊髓损伤的研究进展

目的综述神经干细胞(neural stem cells,NSCs)与BMSCs的免疫学特性及治疗脊髓损伤(spinal cordinjury,SCI)的新进展。方法广泛查阅近年国内外相关文献,对NSCs与BMSCs的免疫学特性、移植治疗SCI的实验研究与可能存在的问题进行分析。结果动物实验表明NSCs与BMSCs移植可促进SCI动物行为学改善,但由于两种干细胞的免疫学特性,同种异体干细胞移植后将产生免疫排斥反应。结论 NSCs与BMSCs对SCI有很好的治疗效果,但是免疫排斥问题值得考虑。