• Biomedical Science Letters
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• v.18 no.2
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• pp.131-138
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• 2012

Autologous peripheral blood stem cell transplantation (PBSCT) has been used as a major treatment strategy for hematological malignancies. The number of CD34 positive cells in the harvested product is a very important factor for achieving successful transplantation. We studied the factors that can predict the number of CD34 positive cells in the harvested product of acute myelocytic leukemia (AML), multiple myeloma (MM) and Non-Hodgkin's lymphoma (NHL) patients after mobilizing them with chemotherapy plus G-CSF. A total of 73 patients (AML 19 patients, MM 28 patients, NHL 26 patients) with hematological malignancies had been mobilized with chemotherapy and granulocyte colony-stimulating growth factor from April, 2000 to February, 2012. Group's characteristics, checkup opinion of pre-peripheral blood on the day of harvest & outcome of PBSC were analyzed and evaluated using SPSS statistics program after grouping patients as below; group 1: CD34 cell counts < $2{\times}10^6/kg$ (n=16); group 2: $2{\times}10^6/kg{\leq}CD34$ cell counts < $6{\times}10^6/kg$ (n=32); group 3: CD34 cell counts ${\geq}6{\times}10^6/kg$ (n=25). We analyzed the clinical characteristics, the peripheral blood (PB) parameters and the number of CD34 positive cells in the PB and their correlation with the yield of CD34 positive cells collected from the mobilized patients. The total number of leukapheresis sessions was 263 (mean: 3.55 session per patient), and the mean number of harvested CD34 positive cells per patient was $7.37{\times}10^6/kg$. The number of CD34 positive cells in product was significantly correlated with the number of platelet and CD34 positive cells in peripheral blood (P<0.05). The number of PB CD34 positive cells was the best significant factor for the quantity of harvested CD34 positive cells on the linear regression analysis (P<0.05). Many factors could influence the mobilization of peripheral blood stem cells. Platelet count and PB CD34 positive cells count were the two variables which remained to be significant in multivariate analysis. Therefore, the number of platelet and CD34 positive cells in peripheral blood on the day of harvest can be used as an accurate predictor for successful peripheral blood stem cell collection.

• Journal of Yeungnam Medical Science
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• v.36 no.2
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• pp.148-151
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• 2019

The dose of CD34+ cells is known to influence the outcome of allogeneic peripheral blood stem cell (PBSC) and/or T-cell-depleted transplantation. A previous study proposed that $2{\times}10^6\;CD34+\;cells/kg$ is the ideal minimum dose for allogeneic transplantation, although lower doses did not preclude successful therapy. In the case we present here, CD34+ cells were collected from a matched sibling donor on the day of allogeneic hematopoietic stem cell transplantation; however, the number of cells was not sufficient for transplantation. Consequently, PBSCs were collected three additional times and were infused along with cord blood cells from the donor that were cryopreserved at birth. The cumulative dose of total nuclear cells and CD34+ cells was $15.9{\times}10^8\;cells/kg$ and $0.95{\times}10^6\;cells/kg$, respectively. White blood cells from this patient were engrafted on day 12. In summary, we report successful engraftment after infusion of multiple low doses of CD34+ cells in a patient with severe aplastic anemia.

• IMMUNE NETWORK
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• v.1 no.1
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• pp.87-94
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• 2001

Background: Cytokine-mediated ex vivo expansion has been proposed as a means of increasing the number of cord blood (CB) hematopoietic stem cells for transplantation. As well as stem cell number, stromal cells are necessary for functional maturation of hematopoiesis. The purpose of this study was to analyze the development of stromal cells during ex vivo expansion of CB $CD34^+$ cells. Methods : $CD34^+$ cells were purified from CB by magnetic bead selection. The levels of of interleukin-3, interleukin-$1{\beta}$, interleukin-6, granulocyte macrophagecolony stimulating factor and tumor necrosis factor-${\alpha}$ were measured in culture supernatants on 0, 1, 2, and 3 weeks, using ELISA techniques. CB $CD34^+$ cells were expanded in Iscoves modified Dulbeccos medium in the presence of several cytokines. The expression of E-selectin, vascular cell adhesion molecule-1, intercellular adhesion molecule-1, platelet/endothelial cell adhesion molecule-1, von Willebrand factor, vimentin, and CD14 in newly developed stromal cells was examined by immunocytochemical method. Relevant extracellular matrix (ECM) proteins and proper cytokines were also assayed for the most suitable condition for expansion of stromal cells. Results: Several cytokines were found to have been produced by CB $CD34^+$ cells as well as bone marrow-derived $CD34^+$ cells. During ex vivo expansion of CB $CD34^+$ cells, stromal cells appeared in the culture by day 4 and expanded over the following 7-10 days before being confluent by day 2 1. These cells expressed surface markers characteristic of cells of endothelial lineage. Furthermore, these stroaml cells also expanded effectively when treated with thrombopoietin+flt-3 ligand+stem cell factor+leukemia inhibitory factor or 0.1% poly-L-lysine-coated wells. Conclusion: Stromal cells were developed during ex vivo expansion of CB $CD34^+$ cells and that this development could be enhanced further by treating the stromal cells with cytokines or ECM.

• Journal of the korean academy of Pediatric Dentistry
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• v.46 no.3
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• pp.337-342
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• 2019

The aim of this study was to analyze cells from human dental pulp tissue of impacted supernumerary teeth as stem cells with flow cytometry. Human dental pulp cells from 15 supernumerary teeth were identified their characteristics as stem cells by expression of mesenchymal stem cell markers through flow cytometry analysis at passage 3 and passage 10. Cluster of differentiation (CD) 73, CD 90, CD 34, CD 45 and STRO-1 cell surface markers were used to figure out characteristics of dental pulp stem cells from supernumerary teeth. At passage 3, the cell population showed positive expression of CD 73, CD90 and STRO-1, lacked expression of CD 34 and CD 45. At passage 10, CD 73, CD 90 and STRO-1 showed positive expression while CD 34 and CD 45 showed negative expression. This study indicated that dental pulp stem cells of supernumerary teeth had the properties of mesenchymal stem cells at both early and late passage. Impacted supernumerary teeth could be considered as a noble source of stem cells because of rapid growth and maintaining characteristics of stem cells until late passage.

• Clinical and Experimental Pediatrics
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• v.48 no.8
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• pp.894-900
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• 2005

Purpose : Because of the unavailability of marrow transplantation, umbilical cord blood (CB) is increasingly being used. We evaluated the potential of ex vivo expansion and clonality in CD34+ cells separated from cord blood source and mobilized peripheral blood (PB) in a serum-free media. Methods : The CD34+ cells, selected from CB and mobilized PB, were expanded with hematopoietic growth factors. They were then cultured for burst-forming units of erythrocytes (BFU-E), colony-forming units of granulocytes and monocytes (CFU-GM) and colony-forming units of megakaryocytes (CFU-Mk) at culture days 0, day 4, day 7, and day 14 with various growth factors. Results : The CB-selected CD34+ cells showed significantly higher total cell expansion than those from the PB at day 7 (2 fold increase than PB). The CB-selected CD34+ cells produced more BFU-E colonies than did the PB on culture at days 7 and at day 14. Also, the CB-selected CD34+ cells produced more CFU-Mk colonies than did the PB on culture at day 4 and at day 7. Conclusion : The ex vivo expansion of the CB cells may be promising in producing total cellular expansion, CFU-Mk and BFU-E compared with PB for 7 to 14 days. The growth factors combination including megakaryocyte growth and development, flt3-ligand and interleukin-3 showed more expansion in the view of total cells and clonal maintenance compared with less combination.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.11
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• pp.6549-6556
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• 2013

Leukemia stem cells (LSCs) play important roles in leukemia initiation, progression and relapse, and thus represent a critical target for therapeutic intervention. Hence, it is extremely urgent to explore new therapeutic strategies directly targeting LSCs for acute myelogenous leukemia (AML) therapy. We show here that Angelica sinensis polysaccharide (ASP), a major active component in Dong quai (Chinese Angelica sinensis), effectively inhibited human AML $CD34^+CD38^-$ cell proliferation in vitro culture in a dose-dependent manner while sparing normal hematopoietic stem and progenitor cells at physiologically achievable concentrations. Furthermore, ASP exerted cytotoxic effects on AML K562 cells, especially LSC-enriched $CD34^+CD38^-$ cells. Colony formation assays further showed that ASP significantly suppressed the formation of colonies derived from AML $CD34^+CD38^-$ cells but not those from normal $CD34^+CD38^-$ cells. Examination of the underlying mechanisms revealed that ASP induced $CD34^+CD38^-$ cell senescence, which was strongly associated with a series of characteristic events, including up-regulation of p53, p16, p21, and Rb genes and changes of related cell cycle regulation proteins P16, P21, cyclin E and CDK4, telomere end attrition as well as repression of telomerase activity. On the basis of these findings, we propose that ASP represents a potentially important agent for leukemia stem cell-targeted therapy.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.31 no.1
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• pp.39-45
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• 2005

Stem cell therapy using mesenchymal stem cells(MSCs) transplantation have been paid attention because of their powerful proliferation and pluripotent differentiating ability. Although umbilical cord blood (UCB) is well known to be a rich source of hematopoietic stem cells with practical and ethical advantages, the presence of mesenchymal stem cells (MSCs) in UCB has been controversial and it remains to be validated. In this study, we examine the presence of MSCs in UCB harvests and the prevalence of them is compared to that of endothelial progenitor cells. For this, CD34+ and CD34- cells were isolated and cultured under the endothelial cell growth medium and mesenchymal stem cell growth medium respectively. The present study showed that ESC-like cells could be isolated and expanded from preterm UCBs but were not acquired efficiently from full-terms. They expressed CD14-, CD34-, CD45-, CD29+, CD44+, CD105+ cell surface marker and could differentiate into adipogenic and osteogenic lineages. Our results suggest that MSCs are fewer in full-term UCB compared to endothelial progenitor cells.

• Korean Journal of Clinical Laboratory Science
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• v.39 no.3
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• pp.210-216
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• 2007

There is increasing evidence that stromal reaction in cancer has an important diagnostic and prognostic significance. The aim of our study is to analyze the relation between the increase in mast cell number and the expression CD34 and alpha-smooth muscle actin (${\alpha}$-SMA) in the stroma of cervical intraepithelial neoplasia (CIN) and squamous cell carcinoma (SCC). We investigated a total of 29 CIN (1,2,3) and 21 SCC (microinvasive and invasive) specimens and compared the distribution of $CD34^+$ stromal cells, ${\alpha}-SMA^+$ cells, transforming growth factor-${\beta}1$ $(TGF-{\beta}1)^+$ cells, and the density of mast cells using immunohistochemistry with antibodies against CD34, ${\alpha}$-SMA, TGF-${\beta}1$, and c-Kit (CD117) respectively. Computerized image analysis was to evaluate the positive area (%) and density of the respective immunoreactive cells. In CIN $CD34^+$ cells were abundant in the stroma but no ${\alpha}-SMA^+$ cells were identified except the wall of blood vessels. $CD34^+$ cells were progressively decreased along the continuum from CIN 2 to microinvasive SCC and not observed in the stroma of invasive SCC. Whereas ${\alpha}-SMA^+$ cells were only observed in the stroma of microinvasive and invasive SCC. We found more intense TGF-${\beta}1$ expression in the increased mast cells in the stroma of invasive SCCs than that in the stroma of CIN. These results indicate that disappearance of $CD34^+$ stromal cells and appearance of ${\alpha}-SMA^+$ cells are associated with the stromal change of CIN to SCC and the transformation of $CD34^+$ stromal cells into ${\alpha}-SMA^+$ cells is mediated by TGF-${\beta}1$ secretions in the stromal mast cell of SCC.

• Proceedings of the Membrane Society of Korea Conference
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• 2004.05a
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• pp.55-58
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• 2004

Cell separation from peripheral blood was investigated using surface-modified polyurethane (PU) membranes with different functional groups. Both red blood cells and platelets could pass through unmodified PU and PU-SO$_3$H membranes, while the red blood cells preferentially passed through PU-N(C$_2$H$_{5}$ )$_2$ and PU-NHC$_2$H$_4$OH membranes. The permeation ratio of T and B cells was less than 25% for the surface-modified and unmodified PU membranes. CD34$^{+}$ cells have been recognized as various kinds of stem cells including hematopoietic and mesenchymal stem cells. The adhesiveness of CD34$^{+}$ cells on the PU membranes was found to be higher than that of red blood cells, platelets, T cells or B cells. Overall, the adhesiveness of blood cells on the PU membranes increased in the following order: red blood cells $\leq$ platelets ＜ T cells $\leq$ B cells ＜ CD34$^{+}$ cells. Treatment of PU-COOH membranes with a human albumin solution to detach adhered blood cells, allowed recovery of mainly CD34$^{+}$ cells in the permeate, while both red blood cells and platelets could be isolated in the permeate using unmodified PU membranes. The PU membranes showed different permeation and recovery ratios of specific cells depending on the functional groups attached to the membranes.mbranes.

• Journal of Microbiology and Biotechnology
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• v.13 no.3
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• pp.422-428
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• 2003

Umbilical cord blood (UCB), a rich source of hematopoietic stem/progenitor cells, has been proposed as an alternative to bone marrow and peripheral blood for transplantation treatment. Ex vivo expansion of cord blood stem cells could make the use of cord blood transplant feasible even for adult patients. However, the optimal cytokine cocktail for expansion of stem cells is yet to be established. This study compares proliferation, apoptosis, and telomerase activities in human cord blood stem cells cultured ex vivo with FLT3 ligand (FL)/thrombopoietin (TPO) or FL/TPO/stem cell factor (SCF), with a view to determine optimal combination of cytokines. CD34+ cells were cultured in DMEM containing either FL (50 ng/ml) and TPO (10 ng/ml) (FT group) or FL (50 ng/ml), TPO (10 ng/ml) and SCF (50 ng/ml) (FTS group). The cell proliferation rate was ten times higher in the FTS group. Although cells cultured with the two different combinations of cytokines were maintained for a long term (up to 8 weeks), a large number of cells underwent differentiation during this period. Cells cultured in FTS displayed lower levels of apoptosis compared to those of the FT group during the Initial 7 days of culture. The CD34+ fraction in both groups was markedly decreased to $21-30\%$ , and only $5-6\%$ was detected at 14 days of culture. Telomerase activity detected in human CD34+ cord blood at low levels was upregulated during the early phase of culture and decreased to baseline levels in the later phase. The telomerase activity of cord blood cultured in FT was lower than that of the FTS group. Our results suggest that, on adding stem cell factors to the FT cytokines, cultured CD34+ cord blood cells display a greater degree of cell proliferation and decreased apoptosis. However, during CD34+ cord blood cell culture, a Barge number of cells undergo differentiation, indicating that more potent novel cytokines or new culture conditioning methods should be developed to maintain their ability to engraft and sustain long-term hematopoiesis.