人脐带和骨髓源间充质干细胞生物学特征的对比研究

为了对比人脐带组织源间充质干细胞（UC-MSC）与骨髓源间充质干细胞（BM-MSC）的生物学特性,从足月胎儿脐带组织和成人骨髓中分离出间充质干细胞（MSC）。用有限稀释法、流式细胞术、倒置显微镜检及RT-PCR等方法检测UC-MSC和BM-MSC的分离成功率、细胞产量、成纤维细胞集落形成单位（CFU-F）、增殖特性、免疫表型和多向诱导分化能力等并对比性研究二者的生物学特性。结果表明,UC-MSC和BM-MSC的分离成功率均达100%;虽然由脐带组织中分离的有核细胞数低于骨髓（1×10^6/cmvs5.5×10^7/ml）（p=0.0002）,但在培养第14天由脐带和骨髓中得到的贴壁细胞数无差异（8.6×10^5/cmvs8.4×10^5/ml）（p〉0.05）;UC-MSC形态、大多数分子表型、细胞周期状态、脂肪和骨诱导分化能力与BM-MSC相似,但UC-MSC的CFU-F比例（1∶1609±0.18）高于BM-MSC的CFU-F比例（1∶35700±0.01）（p〈0.05）。此外,UC-MSC具有比BM-MSC更强的增殖能力（p〈0.05）。UC-MSCHLA-ABC和CD106分子表达低于BM-MSC（p〈0.05）。结论：脐带组织源间充质干细胞产量和绝大多数生物学特征与BM-MSC的相似,且具有比BM-MSC更高的增殖能力、较低的HLA-ABC和HLA-DR表达,UC-MSC有望成为BM-MSC理想的替代来源。     

Osteogenic capacity of human BM‐MSCs,AT‐MSCs and their co‐cultures using HUVECs in FBS and PL supplemented media

Human bone marrow‐derived mesenchymal stem cells (BM‐MSCs) and human adipose tissue‐derived mesenchymal stem cells (AT‐MSCs) are the most frequently used stem cells in tissue engineering. Due to major clinical demands, it is necessary to find an optimally safe and efficient way for large‐scale expansion of these cells. Considering the nutritional source in the culture medium and method, this study aimed to analyze the effects of FBS‐ and PL‐supplemented media on osteogenesis in stem cell mono‐ and co‐cultures with human umbilical vein endothelial cells (HUVECs). Results showed that cell metabolic activity and proliferation increased in PL‐ compared to FBS‐supplemented media in mono‐ and co‐cultures for both BM‐MSCs and AT‐MSCs. In addition, calcium deposition was cell type dependent and decreased for BM‐MSCs but increased for AT‐MSCs in PL‐supplemented medium in both mono‐ and co‐cultures. Based on the effects of co‐cultures, BM‐MSCs/HUVECs enhanced osteogenesis compared to BM‐MSCs monocultures in both FBS‐ and PL‐supplemented media whereas AT‐MSCs/HUVECs showed similar results compared to AT‐MSCs monocultures. Copyright © 2013 John Wiley & Sons, Ltd.     

骨髓、脐带及脂肪来源间充质干细胞的成脂能力存在差异

间充质干细胞（mesenchymalstemcells,MSC）的来源非常广泛。由于不同组织来源的影响,MSC之间都会存在一定的差异。本研究分析比较脐带、脂肪及骨髓组织来源的MSC的基本生物学特性。从脐带、脂肪和骨髓分离培养MSC,在显微镜下观察这3种来源的MSC的形态（UC—MSC,AD—MSC和BM—MSC）,用流式细胞术诱导分化试验及定量荧光PCR分别检测UC-MSC,AD-MSC和BM-MSC的免疫表型、分化能力和过氧化物酶增殖激活受体-γ（peroxisomeproliferator—activatedreceptor-1,PPAR-1）mRNA的表达水平。结果表明,UC-MSC、AD-MSC和BM—MSC的形态都是成纤维细胞样;经罗丹明和DAPI染色后,用共聚焦显微镜观察发现它们的细胞形态类似;这三种来源Msc的免疫表型符合Msc的鉴定标准,而且表达水平一致;这三种来源MSC的成骨分化潜能相似,而成脂分化潜能存在较明显的差异,其中AD—MSC成脂能力最强,BM-MSC次之,UC-MSC最差。检测脂肪形成早期起重要作用的过氧化物酶增殖激活受体-γ（PPAR-1）mRNA表达水平在三种来源MSC中的基础表达水平,发现PPAR-γ mRNA在AD-MSC中最高,在BM—MSC次之,而在UC—MSC中最低,与成脂能力的表现相一致。这表明三种来源MSC成脂能力存在差异可能与它们PPAR-1的基础表达水平有关。结论：UC—MSC,AD—MSC和BM—MSC的形态类似;免疫表型符合MSC鉴定标准,表达水平一致;成骨分化能力相似,而成脂分化能力不同;PPAR-γ mRNA表达水平不一。关于差异的相关机制有待进一步研究。     

人骨髓间充质干细胞中Toll样受体的表达特征

本研究探讨健康供体骨髓源性间充质干细胞（BM—MSC）中Toll样受体（TLR）的表达特征,,用Ficoll法分离培养健康供体的BM—MSC;流式细胞术（FCM）检测BM—MSC中CD34、CD45、HLA—DR、CD44和CD71的表达;免疫细胞化学法检测爬片BM—MSC细胞中CD71的表达;应用茜素红染色和油红染色检测BM—MSC细胞成骨及成脂诱导情况;半定量RT—PCR法检测TLR1—10mRNA的表达。结果表明,体外分离培养的BM—MSC中CD34、CD45和HLA—DR表达呈阴性．CD44和CD71表达呈阳性;爬片BM-MSC细胞中CD71的表达呈阳性。BM—MSC经成骨和成脂诱导后出现钙沉积和脂滴,茜素红染色和油红染色均呈阳性。BM—MSC中TLR1—10mRNA均有表达,其中TLR2、TLR3、TLR4、TI,R7、TLR8、TLR9均高表达,TLR1、TLR5、TLR6、TLR10均低表达。结论：从健康供体骨髓中分离培养的BM—MSC表达不同水平的TLR1-10111RNA。     

大鼠骨髓间充质干细胞对同种异体骨髓移植造血重建的影响

为了探讨大鼠骨髓间充质干细胞(mesenchymal stem cell，MSC)对同种异体骨髓移植造血重建的影响，建立大鼠同种异体骨髓移植模型，通过外周血像检测、病理分析和流式细胞术检测综合评价MSC对骨髓移植(bone marrow transplantation，BMT)的积极作用。结果表明：①共移植后30天，MSC可在致死量照射的受者存活，并被发现受者胸腺、脾脏和骨髓；②MSC可促进BMT后造血重建，促进外周血白细胞、淋巴细胞和血小板的明显恢复；促进骨髓细胞数恢复及B淋巴系、巨核系分化增强；有利骨髓组织学的明显恢复发善。结论：大鼠MSC与骨髓共移植可在受体的造血器官长期存在，MSC可明显促进同种异体骨髓移植后造血S重建。     

骨髓腔输注异基因间充质干细胞对移植后大鼠骨髓间充质干细胞重建的作用

为了研究骨髓腔内注射（IBM）异基因间充质干细胞（MSC）对造血干细胞移植后大鼠骨髓MSC重建的作用，研究供体MSC植入状态以探讨MSCs的作用机制，将雌性F344胎鼠及新生鼠外周血（FNPB）及雄性F344大鼠BrdU标记骨髓MSC共移植入经致死量^60Coγ射线预处理的雌性Wistar大鼠，其中FNPB均由IBM输注，MSC则通过IBM或尾静脉注射。观察受鼠存活状况、供体HSC植入水平及骨髓MSC恢复情况，并以PCR检测Y染色体和免疫荧光法检测受鼠骨髓MSC的来源。结果显示：两个FNPB＋MSCs共移植组大鼠移植后60天均100％存活，两组比较生存率和供体HSC植入水平无统计学差异，但明显优于单纯FNPB移植组；移植后30天时各移植组受鼠骨髓MSC的增殖能力均未达正常水平，但MSC骨髓腔共移植组集落数（66．0±10．6）明显优于MSC骨髓腔和静脉共移植组及单纯FNPB移植组（P〈0．01）；移植后60天时，免疫荧光法检测供体BrdU标记的MSC显示仅在少部分受体发现供、受体源性MSCs嵌合，但两个共移植组存活受鼠均检测到供体MSC来源Y染色体。结论：异基因MSC输注可促进造血干细胞移植受者骨髓MSC恢复，尤以IBM输注为佳。     

Isolation and characterization of mesenchymal cells from human fetal membranes

Bone marrow (BM) multipotent mesenchymal stromal cells (MSCs) present with multipotent differentiation potential and immunomodulatory properties. As an alternative to bone marrow, we have examined fetal membranes, amnion and chorion, of term human placenta as a potential source of multipotent MSCs. Here we show that amnion mesenchymal cells (AMCs) and chorion mesenchymal cells (CMCs), isolated by mechanical separation and subsequent enzymatic digestion, demonstrate plastic adherence and fibroblast-like morphology and are able to form colonies that could be expanded for at least 15 passages. By FACS analysis, AMCs and CMCs were shown to be phenotypically similar to BM-MSCs and, when cultured in differentiation media, they demonstrated high morphogenetic plasticity by differentiating into osteocytes, chondrocytes and adipocytes. In an attempt to isolate cells with MSC characteristics from human fetal membranes, AMCs and CMCs expressing CD271 were enriched by immunomagnetic isolation and were demonstrated to possess higher clonogenic and osteogenic differentiation potential than CD271-depleted fractions. Based on these findings, amnion and chorion can be considered as a novel and convenient source of adult MSCs.     

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。     

A rapid method for obtaining mesenchymal stem cells and platelets from bone marrow aspirate

Mesenchymal stem cells (MSCs) and platelet‐rich plasma (PRP) are currently used alone or in combination for therapeutic applications especially for bone repair. We tested whether MSCs can be isolated from bone marrow (BM) aspirate using a commercially available kit commonly used to obtain PRP from peripheral blood (PB). Results revealed that mononuclear cells and platelets from both PB and BM could be efficiently isolated by obtaining a mononuclear and platelet rich fraction (PB‐MPRF and BM‐MPRF, respectively). Starting with comparable volumes, the number of platelets increased 1.5‐fold in BM‐MPRF compared to PB‐MPRF. The number of clonogenic cells in BM‐MPRF samples was significantly higher than whole BM samples as revealed by CFU‐F assay (54.92 ± 8.55 CFU‐F/1.5 x 10⁵ nucleated cells and 32.50 ± 12.43 CFU‐F/1.5 x 10⁵ nucleated cells, respectively). Cells isolated from BM‐MPRF after in vitro expansion fulfilled the definition of MSCs by phenotypic criteria, and differentiated along osteogenic, adipogenic and chondrogenic lineages following induction. Results showed that the kit isolated MSCs and platelets from BM aspirate. Isolated MSCs were further expanded in a laboratory and BM‐MPRF was used clinically following BM withdrawal for rapid intra‐operative cell therapy for the treatment of bone defects. Copyright © 2012 John Wiley & Sons, Ltd.     

Ectopic bone formation by aggregated mesenchymal stem cells from bone marrow and adipose tissue: A comparative study

Tissue engineered constructs (TECs) based on spheroids of bone marrow mesenchymal stromal cells (BM‐MSCs) combined with calcium phosphate microparticles and enveloped in a platelet‐rich plasma hydrogel showed that aggregation of MSCs improves their ectopic bone formation potential. The stromal vascular fraction (SVF) and adipose‐derived MSCs (ASCs) have been recognized as an interesting MSC source for bone tissue engineering, but their ectopic bone formation is limited. We investigated whether aggregation of ASCs could similarly improve ectopic bone formation by ASCs and SVF cells. The formation of aggregates with BM‐MSCs, ASCs and SVF cells was carried out and gene expression was analysed for osteogenic, chondrogenic and vasculogenic genes in vitro. Ectopic bone formation was evaluated after implantation of TECs in immunodeficient mice with six conditions: TECs with ASCs, TECs with BM‐MSC, TECs with SVF cells (with and without rhBMP2), no cells and no cells with rhBMP2. BM‐MSCs showed consistent compact spheroid formation, ASCs to a lesser extent and SVF showed poor spheroid formation. Aggregation of ASCs induced a significant upregulation of the expression of osteogenic markers like alkaline phosphatase and collagen type I, as compared with un‐aggregated ASCs. In vivo, ASC and SVF cells both generated ectopic bone in the absence of added morphogenetic proteins. The highest incidence of bone formation was seen with BM‐MSCs (7/9) followed by SVF + rhBMP2 (4/9) and no cells + rhBMP2 (2/9). Aggregation can improve ectopic bone tissue formation by adipose‐derived cells, but is less efficient than rhBMP2. A combination of both factors should now be tested to investigate an additive effect.     

急性髓系白血病和非白血病骨髓间充质干细胞生物学特性的比较

本研究旨在比较急性髓系白血病的间充质干细胞（MSC）、急性髓系白血病完全缓解后骨髓MSC以及非白血病的MSC的三者生物学特性。将骨髓MSC分为3组：白血病组、完全缓解组以及非白血病组。采用光学显微镜观察各组MSC的形态学特征,在原位瑞氏染色后计数各组CFU-F数,计数各组MSC的融合时间,绘制各组MSC的生长曲线,应用流式细胞仪检测各组MSC的免疫表型及细胞周期并计算DI值。结果发现,3组骨髓MSC的形态无差异;3组原代MSC的CFU-F数有差异（P=0．01）,其中白血病组MSC的CFU—F最少;3组原代MSC的融合时间有差异（P〈0．01）,其中白血病MSC组的融合时间最长;在第3、5、7天对3组MSC（第2代）的细胞计数进行比较,结果无显著性差异（P〉0．05）;3组MSC（第二代）免疫表型检测显示CD105、CD106均为高表达,CIM5表达阴性,3组间结果比较无差异（P值分别为0．37、0．50）;各组MSC（第二代）的G0／G1期细胞比例分别为（89．9±4．0）％,（90．2±3．0）％,（91．0±3．0）％,3组比较未显示差异（P=0．79）。3组MSC的DI值都在0．9-1．1范围之内。结论：在对白血病与非白血病的第二代MSC的生物学特性比较中,未发现有显著性差异。     

Liver extracellular matrix promotes BM‐MSCs hepatic differentiation and reversal of liver fibrosis through activation of integrin pathway

In cell‐based therapies for liver injuries, the clinical outcomes are closely related to the surrounding microenvironment of the transplanted bone marrow mesenchymal stem cells (BM‐MSCs). However, whether liver‐specific ECM (L‐ECM), as one of major microenvironment signals, could regulate the therapeutic effect of BM‐MSCs through changing their biological characteristics is unclear. This study aimed to investigate the hepatogenicity and underlying mechanism of L‐ECM as well as its potential regulative role in the MSC‐based liver recovery. L‐ECM was prepared by homogenization of decellularized whole porcine liver. After three‐dimensional culture with or without the presence of L‐ECM, BM‐MSCs expressed hepatocyte‐specific genes and proteins in an L‐ECM concentration‐dependent manner. Further analysis showed that L‐ECM could activate specific types of integrins (ITGs) as well as their downstream signalling pathways. When the cell/ECM interaction was enhanced by incorporating BM‐MSCs with Mn²⁺, ITGs were activated and the hepatogenic capacity of L‐ECM was improved. The regeneration of rat livers from either acute or chronic fibrosis could also be accelerated after transplantation of Mn²⁺‐treated BM‐MSCs. L‐ECM therefore promotes hepatic differentiation of BM‐MSCs via the ITG pathway and plays a therapeutically beneficial role for stem cell‐based liver regeneration. Copyright © 2016 John Wiley & Sons, Ltd.     

TGF-β3诱导骨髓间充质干细胞表达软骨细胞表型的实验研究

目的探讨TGF-β3体外诱导骨髓间充质干细胞分化为软骨细胞的可行性。方法分离培养骨髓间充质干细胞,鉴定其表面抗原,用含10%胎牛血清以及10ng/mL转化生长因子TGF-β3的条件培养基诱导,诱导后细胞通过软骨细胞特征性染色鉴定。结果骨髓间充质干细胞表面抗原CD29、CD44、CD105阳性,CD34、CD45、CD106以及HLA-DR阴性。诱导后细胞形态明显改变,甲苯氨蓝以及Ⅱ型胶原染色结果阳性。结论TGF-β3具有促进骨髓间充质干细胞在体外分化为软骨细胞的能力,可以作为组织工程种子细胞的一种有效来源。     

Mesenchymal progenitor cells derived from traumatized human muscle

Mesenchymal stem cells (MSCs) derived from adult tissues are an important candidate cell type for cell‐based tissue engineering and regenerative medicine. Currently, clinical applications for MSCs require additional surgical procedures to harvest the autologous MSCs (i.e. from bone marrow) or commercial allogeneic alternatives. We have recently identified a population of mesenchymal progenitor cells (MPCs) in traumatized muscle tissue that has been surgically debrided from traumatic orthopaedic extremity wounds. The purpose of this study was to evaluate whether MPCs derived from traumatized muscle may provide a clinical alternative to bone‐marrow MSCs, by comparing their morphology, proliferation capacity, cell surface epitope profile and differentiation capacity. After digesting the muscle tissue with collagenase, the MPCs were enriched by a direct plating technique. The morphology and proliferation rate of the muscle‐derived MPCs was similar to bone‐marrow derived MSCs. Both populations expressed cell surface markers characteristic for MSCs (CD 73, CD 90 and CD105), and did not express markers typically absent on MSCs (CD14, CD34 and CD45). After 21 days in specific differentiation media, the histological staining and gene expression of the MPCs and MSCs was characteristic for differentiation into osteoblasts, chondrocytes and adipocytes, but not into myoblasts. Our findings demonstrate that traumatized muscle‐derived MPCs exhibit a similar phenotype and resemble MSCs derived from the bone marrow. MPCs harvested from traumatized muscle tissue may be considered for applications in tissue engineering and regenerative medicine following orthopaedic trauma requiring circumferential debridement. Copyright © 2009 John Wiley & Sons, Ltd.     

The regenerative medicine laboratory: facilitating stem cell therapy for equine disease

This article focuses on the emerging field of equine regenerative medicine with an emphasis on the use of mesenchymal stem cells (MSCs) for orthopedic diseases. We detail laboratory procedures and protocols for tissue handling and MSC isolation, characterization, expansion, and cryopreservation from bone marrow, fat, and placental tissues. We provide an overview of current clinical uses for equine MSCs and how MSCs function to heal tissues. Current laboratory practices in equine regenerative medicine mirror those in the human field. However, the translational use of autologous and allogeneic MSCs for patient therapy far exceeds what is currently permitted in human medicine.     

再生障碍性贫血患儿骨髓间充质干细胞的生物学特点

为了观察和比较再生障碍性贫血患儿、正常同年龄段儿童和胎儿3种来源的骨髓间充质干细胞（MSC）的体外增殖能力及表面标志的表达,利用体外培养的方法从再生障碍性贫血患儿的骨髓分离培养MSC,以胎儿和儿童的MSC作为对照;通过对细胞形态和生长特性的观察,并用流式细胞术和免疫细胞化学方法进行检测以比较三者之间的异同.结果表明：从再生障碍性贫血患儿骨髓中分离、培养、扩增得到了MSC,与胎儿和正常儿童骨髓来源的MSC在细胞形态、流式表达模式和免疫细胞化学表达方面基本一致,但再生障碍性贫血患儿骨髓MSC的体外扩增能力有别于胎儿及正常儿童.虽然在早期培养时再生障碍性贫血患儿的骨髓MSC具有与正常儿童相似的扩增速度,但当群体倍增值（population doubling,PD）达20之后基本不再有增殖能力了,而正常儿童和胎儿来源的MSC却可稳定扩增到30 PD.结论：再生障碍性贫血患儿骨髓MSC在表面抗原标志方面与对照组相比无明显异常,但体外增殖能力弱于对照组.     

Local delivery of allogeneic bone marrow and adipose tissue‐derived mesenchymal stromal cells for cutaneous wound healing in a porcine model

Wound healing remains a major challenge in modern medicine. Bone marrow‐ (BM) and adipose tissue‐ (AT) derived mesenchymal stromal/stem cells (MSCs) are of great interest for tissue reconstruction due to their unique immunological properties and regenerative potential. The purpose of this study was to characterize BM and AT‐MSCs and evaluate their effect when administered in a porcine wound model. MSCs were derived from male Göttingen Minipigs and characterized according to established criteria. Allogeneic BM‐ or AT‐MSCs were administered intradermally (1 x 10⁶ cells) into partial‐thickness wounds created on female animals, and covered with Vaseline® gauze or fibrin in a randomized pattern. Animals were euthanized at 7, 10, 14 and 21 days. Tissues were analyzed visually for healing and by microscopic examination for epidermal development and remodelling. Polymerase chain reaction (PCR) was used to detect the presence of male DNA in the specimens. All wounds were healed by 14 days. MSC‐injected wounds were associated with improved appearance and faster re‐epithelialization compared to saline controls. Evaluation of rete ridge depth and architecture showed that MSC treatment promoted a faster rate of epidermal maturation. Male DNA was detected in all samples at days 7 and 10, suggesting the presence of MSCs. We showed the safety, feasibility and potential efficacy of local injection of allogeneic BM‐ and AT‐MSCs for treatment of wounds in a preclinical model. Our data in this large animal model support the potential use of BM‐ and AT‐MSC for treatment of cutaneous wounds through modulation of healing and epithelialization. Copyright © 2013 John Wiley & Sons, Ltd.     

Cell–cell interaction between vocal fold fibroblasts and bone marrow mesenchymal stromal cells in three‐dimensional hyaluronan hydrogel

Mesenchymal stromal cells (MSCs) are multipotential adult cells present in all tissues. Paracrine effects and differentiating ability make MSCs an ideal cell source for tissue regeneration. However, little is known about how interactions between implanted MSCs and native cells influence cellular growth, proliferation, and behaviour. By using an in vitro three‐dimensional (3D) co‐culture assay of normal or scarred human vocal fold fibroblasts (VFFs) and bone marrow‐derived MSCs (BM‐MSCs) in a uniquely suited hyaluronan hydrogel (HyStem–VF), we investigated cell morphology, survival rate, proliferation and protein and gene expression of VFFs and BM‐MSCs. BM‐MSCs inhibited cell proliferation of both normal and scarred VFFs without changes in VFF morphology or viability. BM‐MSCs demonstrated decreased proliferation and survival rate after 7 days of co‐culture with VFFs. Interactions between BM‐MSCs and VFFs led to a significant increase in protein secretion of collagen I and hepatocyte growth factor (HGF) and a decrease of vascular endothelial growth factor (VEGF), monocyte chemotactic protein‐1 (MCP‐1) and interleukin‐6 (IL‐6). In particular, BM‐MSCs significantly upregulated matrix metalloproteinase 1 (MMP1) and HGF gene expression for scarred VFFs compared to normal VFFs, indicating the potential for increases in extracellular matrix remodelling and tissue regeneration. Application of BM‐MSCs‐hydrogels may play a significant role in tissue regeneration, providing a therapeutic approach for vocal fold scarring. Copyright © 2013 John Wiley & Sons, Ltd.     

Two versus three day upfront use of granulocyte-colony stimulating factor in healthy bone marrow donors for pediatric bone marrow transplantation

In order to decrease donors’ exposure to granulocyte-colony stimulating factor (G-CSF), we compared the effect of two versus three days of G-CSF priming on CD34+ yield in bone marrow (BM) harvest. Although the number of BM-CD34+ cells was higher in 3 day G-CSF priming, we achieved the same number of CD34+ cells per recipient’s weight in 2 day G-CSF priming group, too. In addition, the number of total nucleated cells (TNC) harvested from BM were similar with two or three day regimen. But mononuclear cells (MNC) of the BM graft was higher in the 3 day G-CSF priming group. Similar to CD34+ cell numbers, BM harvest yielded similar TNC, and MNC numbers per kilogram of the recipient. We also found that, young donors (≤10 year) had more peripheral blood MNC, bone marrow MNC and CD34+ cell numbers. Another interesting finding of this study was obtaining adequate number of peripheral blood stem cells for leukapheresis with three day G-CSF administration. Since engrafment times were also similar in two groups, we concluded that 2-days G-CSF priming was resulted in sufficient mobilization of BM stem cells.