PURPOSE: Many studies for hematopoietic stem cell have investigated CD133, instead of CD34, as a new surrogate stem cell marker. Counterflow centrifugal elutriation (CCE) is a physical separation of a homogeneous cell population through cell sedimentation characteristics. We evaluated the stem cell distribution and hematopoietic function from cord blood (CB) and bone marrow (BM) through CCE. METHODS: We obtained total nucleated cells from CB and BM, and separated the cell fractions according to media infusion flow rates (17 mL/min (FR 17), 24 mL/min (FR 24), 29 mL/min (FR 29), and rotor off (R/O) ) by CCE. We analyzed the proportion of CD34+ and CD133+ cells in each fraction, and performed methylcellulose-based colony assay. RESULTS: In CB, the cell recovery rates after CCE were 5.9+/-4.3% in FR 17, 4.2+/-2.1% in FR 24, 19.4+/-11.9% in FR 29, and 61.9+/-11.7% in R/O. In BM, they were 14.9+/-8.2% in FR 17, 17.4+/-13.4% in FR 24, 23.6+/-6.11% in FR 29, and 27.1+/-8.9% in R/O. The distributions of CD133+ and CD34+ cells in CB were more abundant in R/O (2.91%, 1.85%) than in other fractions. In BM, CD133+ and CD34+ cell rates in R/O (5.40%, 2.75%) were similar with those in unmanipulated BM (5.48%, 2.78%). In both CB and BM, there was more CFU-GM and BFU-E in R/O than in other fractions. CONCLUSION: We suggested that the distribution of CD34+ and CD133+ cells might be different between CB and BM. However, the R/O containing relatively large cells could have an effective clonogenicity compared with the unmanipulated sample in both CB and BM.
Bone Marrow* ; Erythroid Precursor Cells ; Fetal Blood* ; Granulocyte-Macrophage Progenitor Cells ; Hematopoietic Stem Cells ; Stem Cells

BACKGROUND: Based on the unlimited proliferative and self-renewel properties of cancer cells similar to those of stem cells, the idea that cancer may originate from stem cells has been suggested in many different studies and has given rise to cancer stem cell hypothesis. CD133, being normally expressed on the surface of hematopoietic stem cells, has recently been suggested as a marker of cancer stem cells in several malignancies. CD24 and CD44 are membrane proteins reported as markers of various neoplasms. OBJECTIVE: This study was designed to investigate the immunohistochemical expression of the CD24, CD44 and CD133 in squamous cell carcinoma (SCC), basal cell carcinoma (BCC) and malignant melanoma (MM). METHODS: We performed immunohistochemical staining for CD24, CD44 and CD133 using 18 skin cancer tissue samples, including 6 SCCs, 6 BCCs and 6 MMs. The expression of each marker was standardized by the histochemical score (HSCORE). RESULTS: The expression of CD24 showed positive in 1 case of 6 SCCs (mean HSCORE, H; 0.02) and showed negative in 6 BCCs (H; 0.00), 6 MMs (H; 0.00). The expression of CD44 was not observed in 6 SCCs (H; 0.00) but observed in 1 case of 6 BCCs (H; 0.04) and 1 case of 6 MMs (H; 0.03). The expression of CD133 showed positive in 2 cases of 6 SCCs (H; 1.21) and 1 case of 6 BCCs (H; 0.05) and 6 cases of 6 MMs (H; 2.78). CONCLUSION: Our data suggest that CD133 may be a reliable marker of which the higher expression is observed in the more invasive skin cancers and that the existence of cancer stem cells may enhance tumorigenic potential in cutaneous malignant tumors.
Carcinoma, Basal Cell ; Carcinoma, Squamous Cell ; Hematopoietic Stem Cells ; Melanoma ; Membrane Proteins ; Neoplastic Stem Cells ; Skin Neoplasms ; Stem Cells

The theory of evolution of tumor cell population has been established for nearly 40 years. It was widely accepted for research and clinical anti-tumor treatment. Recently, it was suggested that cancer stem cells are the unit of evolution. Considering recent advances on genesis of tumor and leukemia with ecological and evolutionary views, this article reviews origin and evolution of leukemia stem cells. Over the last few years, clinical and experimental data suggest there are two paths for the origin of leukemia stem cells: from a transformed hematopoietic stem cell or progenitor. The mechanisms of leukemia stem cell formation and clonal evolution were elucidated. Sub-clonal mutations and clonal architectures in leukemia were studied and a mosaic evolution pattern is described. Random evolution or non-inherited mutations of leukemia cells would accelerate the progression of malignant disease. Finally, the mosaic or network mechanism for leukemogenesis is also discussed.
Clonal Evolution ; Disease Progression ; Hematopoietic Stem Cells ; Humans ; Leukemia ; Mutation ; Neoplastic Stem Cells

Clinical evidence of hematopoietic restoration with umbilical cord blood (UCB) grafts indicates the UCB can be a useful source of hematopoietic stem cells for routine bone marrow reconstitution. Considering (10 +/- 5) x 10(8) nucleared cells per cord blood unit, there is a potential limitation for the use of cord blood in adults, which, however, can be overcome by ex vivo expansion of cells. A prerequisite for expansion is the significantly higher recovery of MNC, CD34+ cells and colony-forming cells (CFC) by thawing cryopreserved MNC. Cooling rate always acts as a critical factor that can affect the recovery of cells. Although the rate of - 1 degrees C/min is adopted in most of the cryopreservations, no data has been reported about the detailed effects of different cooling rates. The aim of the study was to reveal the different effects of cooling rates on cryopreservation of hematopoietic stem cells from cord blood. UCB samples were collected, and cryopreserved as mononuclear cells (MNC) with different cooling rates of - 0.5 degrees C/min, - 1 degrees C/min, - 5 degrees C/min, and the recovery and viability of MNC and CD34+ cells, the clonogenic capacity and the ex vivo expansion potential of UCB progenitor cells were evaluated after thawing. With - 1 degrees C/min cooling rate, the recovery of MNC reached 93.3% +/- 1.8% , viability 95.0% +/- 3.9% , recovery of CD34+ cells 80.0% +/- 17.9% , and clonogenic recovery were 87.1% +/- 5.5%, 88.5% +/- 8.9%, 86.2% +/- 7.4% for BFU-E CFU-GM CFU-MK, respectively. After 14 days of liquid culture, no significant difference was detected in CFC expansion between fresh and cryopreserved MNC cells with - 1 degrees C/min cooling rate, but this was not the case with - 0.5 degreesC/min and - 5 degrees C/min. In conclusion, it was demonstrated that controlling the rate at - 1 degrees C/min is more suitable for cryopreservation of hematopoietic stem cells than - 0.5 degrees C/min and - 5 degrees C/min.
Cell Survival ; physiology ; Cells, Cultured ; Cryopreservation ; methods ; Erythroid Precursor Cells ; cytology ; Fetal Blood ; cytology ; Flow Cytometry ; Granulocyte-Macrophage Progenitor Cells ; cytology ; Hematopoietic Stem Cells ; cytology ; Humans

BACKGROUND: Embryonic stem cells (ESCs) can be expanded infinitely in vitro and have the potential to differentiate into hematopoietic stem cells (HSCs); thus, they are considered a useful source of cells for HSC production. Although several technical in vitro methods for engineering HSCs from pluripotent stem cells have been developed, clinical application of HSCs engineered from pluripotent stem cells is restricted because of the possibility of xenogeneic contamination resulting from the use of murine materials. METHODS: Human ESCs (CHA-hES15) were cultured on growth factor-reduced Matrigel-coated dishes in the mTeSR1 serum-free medium. When the cells were 70% confluent, we initiated HSC differentiation by three methods involving (1) knockout serum replacement (KSR), cytokines, TGFb1, EPO, and FLT3L; (2) KSR, cytokines, and bFGF; or (3) cytokines and bFGF. RESULTS: Among the three differentiation methods, the minimal number of cytokines without KSR resulted in the greatest production of HSCs. The optimized method resulted in a higher proportion of CD34⁺CD43⁺ hematopoietic progenitor cells (HPCs) and CD34⁺CD45⁺ HPCs compared to the other methods. In addition, the HSCs showed the potential to differentiate into multiple lineages of hematopoietic cells in vitro. CONCLUSION: In this study, we optimized a two-step, serum-free, animal protein-free, KSR-free, feeder-free, chemically defined monolayer culture method for generation of HSCs and hematopoietic stem and progenitor cells (HSPCs) from human ESCs.
Animals ; Cytokines ; Embryonic Stem Cells ; Hematopoietic Stem Cells* ; Human Embryonic Stem Cells* ; Humans* ; In Vitro Techniques ; Methods* ; Pluripotent Stem Cells ; Stem Cells

OBJECTIVETo explore the role of bromodomain and extra terminal (BET) bromodomain in hematopoietic differentiation from human enbryonic stem cells (hESC).

METHODSThe effect of BET hematopoietic inhibitor I-BET151 on hematopoietic differentiation from hESC was detected by using a monolayer hematopoietic defferentiation model, immunofluorescence, flow cytometry and real-time PCR; moreover the role of I-BET151 in process of hematopoietic differentiation was explored by adding I-BET151 in different differentiation stages.

RESULTSThe analysis results of immunofluorescence, flow cytometry and real-time PCR showed that I-BET 151 significantly inhibited the generation of CD43 positive hematopoietic stem and progenitor cells (HSPCs). It was found that the addition of I-BET 151 in different stages, including APLNR lateral plate mesoderm production, CD34CD31 hemogenic endothelium (HEP) generation and endothelial-to-hematopoietic transition, significantly suppressed the generation of CD43 positive hematopoietic progenitor cells.

CONCLUSIONI-BET 151 inhibites hematopoietic differentiation from hESCs at several stages, suggesting that the BET bromodomain plays important roles in multiple stages of hematopoietic differentiation from hESCs.

Apelin Receptors ; Cell Differentiation ; Flow Cytometry ; Hemangioblasts ; Hematopoietic Stem Cells ; Human Embryonic Stem Cells ; Humans

BACKGROUND: Because there are lower incidence of graft versus host disease in HLA mismatched cord blood transplantation compared to bone marrow transplantation, development of smaller scale cord blood bank could be possible. So we analysed the content of hematopoietic stem cell in cord blood and the distribution of HLA as a basic study for cord blood bank. METHODS: Seventy eight cord bloods were collected in heparinized bottle immediately after caesarian section. After expulsion of placenta, additional cord blood and placental blood were collected with heparinized syringe. Fifteen mL was sent to the laboratory for analysis and the rest was cryopreserved. RESULTS: The mean collected cord blood volume was 96.8mL (range, 55~163mL). And mean 81.8mL (range, 40~148mL) was cryopreserved. It contained mean 7.4x108 (range, 2.8x108~12.2x108) nucleated cells. In 2x105 mononuclear cells, 85 +/- 48 BFU-E, 19 +/- 17 CFU-E, 107 +/- 73 CFU-GM and 124 +/- 113 CFU-GEMM were present. With dextran/albumin thawing media, the viability of cryopreserved cord blood mononuclear cell was better than usual washing method with IMDM (82.3% vs. 74.6% P=0.004). Each cord blood could findHLA full matched, 5 loci matched and 4 loci matched cord blood in the remainders with the probability of 0, 11.9% and 58.4%. CONCLUSION: Development of more smaller scale cord blood bank could be possible compared to bone marrow bank.
Bone Marrow ; Bone Marrow Transplantation ; Erythroid Precursor Cells ; Fetal Blood* ; Graft vs Host Disease ; Granulocyte-Macrophage Progenitor Cells ; Hematopoietic Stem Cells* ; Heparin ; Humans* ; Incidence ; Myeloid Progenitor Cells ; Placenta ; Syringes

Blood transfusion is a well-established cell therapy. However, blood available for transfusion is a limited resource and is available only through donations by healthy volunteers. Moreover, the perpetual and widespread shortage of blood products, problems related to transfusion transmitted infections, and new emerging pathogens have elicited an increase in demand for artificial blood. Therefore, research for alternative RBC substitutes has begun in the 1960s. Hemoglobin-based oxygen carriers (HBOC) and perfluorocarbon-based oxygen carrier (PBOC) were two popular study subjects; however, research on these substitute candidates was halted due to unsatisfactory results and safety issues, including death, in the 1990s. Since then, worldwide efforts to produce RBC have shifted over to stem cell-derived RBC production using cord blood and G-CSF-mobilized peripheral blood stem cells, and some progress has been made. In terms of practical usefulness, however, large-scale production and cost effectiveness are still problematic. Recently, human embryonic stem cells (hESC) and human-induced pluripotent stem cells (hiPSC) have shown the potential to produce RBCs as unlimited cell sources. These two methods using hESCs and hiPSCs are also cost-effective since autologous and O, D negative blood RBCs will be used for alloimmunized patients with multiple alloantibodies or rare blood types (high incidence antigens) as well as universal blood production. We will review the current research on in vitro RBC production from hematopoietic stem cells and pluripotent stem cells and assess future directions in this field.
Blood Substitutes ; Blood Transfusion ; Cell- and Tissue-Based Therapy ; Cost-Benefit Analysis ; Erythrocytes* ; Fetal Blood ; Healthy Volunteers ; Hematopoietic Stem Cells ; Human Embryonic Stem Cells ; Humans ; In Vitro Techniques ; Incidence ; Induced Pluripotent Stem Cells ; Isoantibodies ; Oxygen ; Pluripotent Stem Cells ; Stem Cells*

OBJECTIVETo investigate the effects of oxygen concentration and reactive oxygen species (ROS) on the biological characteristics of hematopoietic stem cells (HSC) and to analyzed the relationship among the oxygen concentration, ROS and the biological characteristics of mouse HSC through simulation of oxygen environment experienced by PB HSC during transplantation.

METHODSThe detection of reactive oxygen species (ROS), in vitro amplification, directional differentiation (BFU-E, CFU-GM, CFU-Mix), homing of adhesion molecules (CXCR4, CD44, VLA4, VLA5, P-selectin), migration rate, CFU-S of NOD/SCID mice irradiated with sublethal dose were performed to study the effect of oxgen concentration and reactive oxygen species on the biological characteristics of mouse BM-HSC and the relationship among them.

RESULTSThe oxygen concentrations lower than normal oxygen concentration (especially hypoxic oxygen environment) could reduce ROS level and amplify more Lin(-) c-kit(+) Sca-1(+) BM HSC, which was more helpful to the growth of various colonies (BFU-E, CFU-GM, CFU-Mix) and to maintain the migratory ability of HSC, thus promoting CFU-S growth significantly after the transplantation of HSC in NOD/SCID mice irradiated by a sublethal dose. BM HSC exposed to oxygen environments of normal, inconstant oxygen level and strenuously thanging of oxygen concentration could result in higher level of ROS, at the same time, the above-mentioned features and functional indicators were relatively lower.

CONCLUSIONThe ROS levels of BM HSC in PB HSCT are closely related to the concentrations and stability of oxygen surrounding the cells. High oxygen concentration results in an high level of ROS, which is not helpful to maintain the biological characteristics of BM HSC. Before transplantation and in vitro amplification, the application of antioxidancs and constant oxygen level environments may be beneficial for transplantation of BMMSC.

Animals ; Cell Differentiation ; Culture Media ; chemistry ; Erythroid Precursor Cells ; cytology ; Granulocyte-Macrophage Progenitor Cells ; cytology ; Hematopoietic Stem Cells ; cytology ; metabolism ; Mice ; Mice, Inbred NOD ; Mice, SCID ; Oxygen ; chemistry ; Reactive Oxygen Species ; metabolism

OBJECTIVE: To investigate the effect of Notch signaling pathways on differentiation of mouse embryonic stem cells(ESC) into haematopoietic stem cells or haematopoietic progenitors cells(HSC/HPC). METHODS: Mouse embryonic stem cells were proliferated in vitro to form embryoid bodies; the differentiation of embryoid bodies should be induced in vitro, the experiments were divided into BE, control, VEGF, DAPT and VEGF-DAPT groups; HSC/HPC ohenotype: CD117D34Sca1 was detected by flow cytometry; the related gene expression was detected by RT-PCR. RESULTS: The number of VEGF-induced HSC/HPC in VEGF group was significantey higher than that in the control and EB group (P<0.05), suggesting that VEGF promotes ESC differentiation to HSC/HPC; the number of DAPT-induced HSC/HPC in DAPT group was significanty higher than that in the Control and EB groups(P<0.05), suggesting that DAPT promotes ESC differentiation to HSC/HPC; the number of VEGF+DAPT-induced HSC/HPC in VEGF-DAPT group was significantly higher than that in VEGF and DAPT groups(P<0.05), suggesting that DAPT and VEGF play a synergistic role to promote differentiation of ESC into HSC/HPC. CONCLUSION Notch signal pathway inhibits differentiation of ESC into HSC / HPC by VEGF.
Animals ; Cell Differentiation ; Hematopoietic Stem Cells ; Mice ; Mouse Embryonic Stem Cells ; Receptors, Notch ; Signal Transduction ; Vascular Endothelial Growth Factor A