• Reproductive and Developmental Biology
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• 제34권3호
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• pp.143-151
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• 2010

Pluripotency of human embryonic stem cell (hESC) is one of the most valuable ability of hESCs for applying cell therapy field, but also showing side effect, for example teratoma formation. When transplant multipotent stem cell, such as mesnchymal stem cell (MSC) which retains similar differentiation ability, they do not form teratoma in vivo, but there exist limitation of cellular source supply. Accordingly, differentiation of hESC into MSC will be promising cellular source with strong points of both hESC and MSC line. In this study, we described the derivation of MSC like cell population from feeder free cultured hESC (hESC-MSC) using direct differentiation system. Cells population, hESC-MSC and bone marrow derived MSC (BM-MSC) retained similar characteristics in vitro, such as morphology, MSC specific marker expression and differentiation capacity. At the point of differentiation of both cell populations, differentiation rate was slower in hESC-MSC than BM-MSC. As these reason, to verify differentially expressed molecular condition of both cell population which bring out different differentiation rate, we compare the molecular condition of hESC-MSC and BM-MSC using 2-D proteomic analysis tool. In the proteomic analysis, we identified 49 differentially expressed proteins in hESC-MSC and BM-MSC, and they involved in different biological process such as positive regulation of molecular function, biological process, cellular metabolic process, nitrogen compound metabolic process, macromolecule metabolic process, metabolic process, molecular function, and positive regulation of molecular function and regulation of ubiquitin protein ligase activity during mitotic cell cycle, cellular response to stress, and RNA localization. As the related function of differentially expressed proteins, we sought to these proteins were key regulators which contribute to their differentiation rate, developmental process and cell proliferation. Our results suggest that the expressions of these proteins between the hESC-MSC and BM-MSC, could give to us further evidence for hESC differentiation into the mesenchymal stem cell is associated with a differentiation factor. As the initial step to understand fundamental difference of hESC-MSC and BM-MSC, we sought to investigate different protein expression profile. And the grafting of hESC differentiation into MSC and their comparative proteomic analysis will be positively contribute to cell therapy without cellular source limitation, also with exact background of their molecular condition.

• 보건행정학회지
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• 제23권4호
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• pp.314-325
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• 2013

Background: Stem cell research competition is accelerating globally since President Obama signed an executive order, repealing Bush-era policy that limited use of federal tax dollars for embryonic stem cell research. Methods: In this paper, we conducted a comparative analysis of stem cell research policy changes in three countries, including the Human Fertilisation Embryology Act (HFEA) of UK, executive order 13,505 (removing barriers to responsible scientific research involving human stem cells) of USA, and Bioethics and Safety Act of South Korea. Debates on stem cell research are based on conflicts of fundamental beliefs that exist in the supporting and opposing coalitions. We compared regional characteristics of the advocacy coalitions in three countries and presented various factors that might be related to the policy changes. Results: The UK government, parliament, and the HFEA have sought expert consultations and public opinions to establish guidelines. UK has made social consensus through continued discussion for a long time. US President's veto power was one strongest factors influencing policy. South Korean policy was influenced by public opinion and policy brokers. Also, South Korea has not made social consensus. UK had a strong leadership and strong adjustment of coalitions but US and South Korea had not. Dr. Hwang's scandal has had one of the greatest impacts on policy decision in South Korea. Conclusion: The power of public opinion was critical in all three countries. In particular, the influence of public opinion was noticeable in South Korea. Also it turned out that in US and South Korea, the presence of a policy broker who could pursue his or her goals was the most powerful factor among the advocacy coalition factors.

• Journal of Korean Neurosurgical Society
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• 제42권2호
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• pp.118-124
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• 2007

Objective : Adipose tissue is derived from the embryonic mesoderm and contains a heterogenous stromal cell population. Authors have tried to verify the characteristics of stem cell of adipose derived stromal cells (ADSCs) and to investigate immunohistochemical findings after transplantation of ADSC into rat brain to evaluate survival, migration and differentiation of transplanted stromal cells. Methods : First ADSCs were isolated from human adipose tissue and induced adipose, osseous and neuronal differentiation under appropriate culture condition in vitro and examined phenotypes profile of human ADSCs in undifferentiated states using flow cytometry and immunohistochemical study. Human ADSCs were transplanted into the healthy rat brain to investigate survival, migration and differentiation after 4 weeks. Results : From human adipose tissue, adipose stem cells were harvested and subcultured for several times. The cultured ADSCs were differentiated into adipocytes, osteoctye and neuron-like cell under conditioned media. Flow cytometric analysis of undifferentiated ADSCs revealed that ADSCs were positive for CD29, CD44 and negative for CD34, CD45, CD117 and HLA-DR. Transplanted human ADSCs were found mainly in cortex adjacent to injection site and migrated from injection site at a distance of at least 1 mm along the cortex and corpus callosum. A few transplanted cells have differentiated into neuron and astrocyte. Conclusion : ADSCs were differentiated into multilineage cell lines through transdifferentiation. ADSCs were survived and migrated in xenograft without immunosuppression. Based on this data, ADSCs may be potential source of stem cells for many human disease including neurologic disorder.

• 대한의생명과학회지
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• 제18권2호
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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 Medicine and Life Science
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• 제15권2호
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• pp.46-50
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• 2018

Cancer, a leading mortality disease following cardiovascular disease worldwide, has high incidence as one out of every four adults in Korea. It was known to be caused by several reasons including somatic mutation, activation of oncogene and chromosome aneuploidy. Cancer cells show a faster growth rate and have metastatic and heterogeneous cell populations compared to normal cells. Cancer stem cells, the most invested field in cancer biology, is a theory to explain heterogeneous cell populations of cancer cells among several characteristics of cancer cells, which is providing the theoretical background for incidence of cancer and treatment failure by drug resistance. Cancer stem cells initially explain heterogeneous cell populations of cancer cells based on the same markers of normal stem cells in cancer, in which only cancer stem cells showed heterogeneity of cancer cells and tumor initiating ability of leukemia. Based on these results, cancer stem cells were reported in various solid cancers such as breast cancer, liver cancer, and lung cancer. Breast cancer stem cells were first reported in solid cancer which had tumor initiating ability and further identified as anti-cancer drug resistance. There were several identification methods in breast cancer stem cells such as specific surface markers and culture methods. The discovery of cancer stem cells not only explains heterogeneity of cancer cells, but it also provides theoretical background for targeting cancer stem cells to complete elimination of cancer cells. Many institutes have been developing new anticancer drugs targeting cancer stem cells, but there have not been noticeable results yet. Many researchers also reported a necessity for improvement of current concepts and methods of research on cancer stem cells. Herein, we discuss the limitations and the perspectives of breast cancer stem cells based on the current concept and history.

• 생명과학회지
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• 제30권7호
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• pp.651-659
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• 2020

허혈성 심혈관질환은 전 세계적으로 치사율이 높은 질병 중 하나이다. 이를 치료하기 위해 수술적 방법이 시행되고 있으나, 손상된 심근조직 회복의 어려움과 수술 후 부작용의 한계가 남아있다. 이러한 한계점을 극복하기 위해, 최근 줄기세포를 기반으로 한 심혈관질환의 세포치료제가 각광받고 있는데 그 중에서도 특히 혈관내피전구세포(EPC)는 높은 증식능과 분화능을 기반으로 손상된 혈관을 재생하고, 주변 조직의 재생을 돕는다는 장점이 있다. 또, EPC는 임상적으로 안전하며, 환자의 심근 기능을 회복시켜주기에 잠재적인 심혈관질환 치료제로서의 가능성이 대두되었다. 하지만, 환자 유래 EPC를 이용한 치료법은, 고령, 흡연 여부, 기저질환 등의 이유로 환자의 EPC 기능이 저하되어 있어, 그 치료 효능을 기대하기 어렵다. 따라서, 최근에는 세포 프라이밍 기법, 오가노이드 배양법과 같이 EPC의 생리학적 활성도를 올리는 체외 배양법의 개발과 3D 바이오프린팅 기법을 이용한 EPC의 이식 효율을 높여 치료 효능을 개선시킬 수 있는 새로운 접근법이 연구되고 있다. 본 연구에서는 EPC의 특징과 세포치료제로서의 임상적용 가능성에 대해 살펴보고자 한다.

• 대한소아치과학회지
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• 제46권3호
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• pp.337-342
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• 2019

이 연구의 목적은 발치한 매복 과잉치에서 얻은 치수 유래 세포의 줄기세포 특성을 유세포 분석을 통해 알아보는 것이다. 15명의 환자로부터 채취한 정중 과잉치의 치수 세포를 계대 배양하였고, 3계대와 10계대 세포들을 유세포 분석을 이용하여 분석하였다. 간엽성 줄기세포 표지자 관찰에 사용된 항체 표지자(CD)는 양성 표지자로는 CD 73, CD 90, 그리고STRO-1 와 음성 표지자로는 CD 34, CD 45 이었다. 3계대에서 CD 73, CD 90은 각각 94.82%, 98.86%의 양성반응을, CD 34, CD 45는 각각 2.25%, 2.52%로 음성 반응을 보였으며, STRO-1은 20.93%를 나타냈다. 10계대에서는 CD 73, CD 90은 각각 96.62%, 98.61%의 발현을 보였지만, CD 34, CD 45는 각각 3.86%, 4.14%를 나타냈다. STRO-1은 35.62%로 발현되었다. 이상의 결과에서 과잉치 치수 유래 세포는 간엽성 줄기세포의 특성을 가지며, 3계대와 10계대 모두에서 간엽성 줄기세포의 특성을 유지하고 있다고 사료된다. 이에 빠른 성장 속도와 늦은 계대까지 유지되는 줄기세포능을 고려할 때, 치아 유래 줄기세포의 공여부로서 매복 과잉치의 충분한 활용 가능성을 확인하였다.

• IMMUNE NETWORK
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• 제2권3호
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• pp.166-174
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• 2002

Background: Human umbilical cord bloods, which could be taken during the delivery are utilized as a source of hematopoietic stem cells. Also in cord blood, there are several kinds of stem cells such as endothelial and mesenchymal stem cells. Methods: We isolated the mesenchymal stem cells from human umbilical cord bloods and confirmed the differentiation of these cells into osteoblast progenitor cells. The mesenchymal stem cells derived from umbilical cord blood have the ability to differentiate into specific tissue cells, which is one of characteristics of stem cells. These cells were originated from the multipolar shaped cells out of adherent cells of the umbilical cord blood mononuclear cell culture. Results: The mesenchymal stem cells expressed cell surface antigen CD13, CD90, CD102, CD105, ${\alpha}$-smooth muscle actin and cytoplasmic antigen vimentine. Having cultrued these cells in bone formation media, we observed the formation of extracellular matrix and the expression of alkaline phosphatase and of mRNA of cbfa-1, ostoecalcin and type I collagen. Conclusion: From these results we concluded that the cells isolated from the umbilical cord blood were mesenchymal stem cells, which we could differentiate into osteoblast when cultured in bone formation media. In short, it is suggested that these cells could be used as a new source of stem cells, which has the probability to alternate the embryonic stem cells.

• Journal of Periodontal and Implant Science
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• 제51권5호
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• pp.329-341
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• 2021

Purpose: Periodontal treatment aims at complete regeneration of the periodontium, and developing strategies for periodontal regeneration requires a deep understanding of the tissues composing the periodontium. In the present study, the stemness characteristics and gene expression profiles of cementum-derived cells (CDCs) were investigated and compared with previously established human stem cells. Candidate marker proteins for CDCs were also explored. Methods: Periodontal ligament stem cells (PDLSCs), pulp stem cells (PULPSCs), and CDCs were isolated and cultured from extracted human mandibular third molars. Human bone marrow stem cells (BMSCs) were used as a positive control. To identify the stemness of CDCs, cell differentiation (osteogenic, adipogenic, and chondrogenic) and surface antigens were evaluated through flow cytometry. The expression of cementum protein 1 (CEMP1) and cementum attachment protein (CAP) was investigated to explore marker proteins for CDCs through reverse-transcription polymerase chain reaction. To compare the gene expression profiles of the 4 cell types, mRNA and miRNA microarray analysis of 10 samples of BMSCs (n=1), PDLSCs (n=3), PULPSCs (n=3), and CDCs (n=3) were performed. Results: The expression of mesenchymal stem cell markers with a concomitant absence of hematopoietic markers was observed in PDLSCs, PULPSCs, CDCs and BMSCs. All 4 cell populations also showed differentiation into osteogenic, adipogenic, and chondrogenic lineages. CEMP1 was strongly expressed in CDCs, while it was weakly detected in the other 3 cell populations. Meanwhile, CAP was not found in any of the 4 cell populations. The mRNA and miRNA microarray analysis showed that 14 mRNA genes and 4 miRNA genes were differentially expressed in CDCs vs. PDLSCs and PULPSCs. Conclusions: Within the limitations of the study, CDCs seem to have stemness and preferentially express CEMP1. Moreover, there were several up- or down-regulated genes in CDCs vs. PDLSCs, PULPSCs, and BMSCs and these genes could be candidate marker proteins of CDCs.

• 종양간호연구
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• 제8권1호
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• pp.1-7
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• 2008

Purpose: Peripheral blood stem cell transplantation (PBSCT) has been widely used. The optimal time for collection is a critical factor to obtain proper counts of CD34 cell by peripheral blood stem cell collection (PBSC). The purpose of this study was to identify the factors influencing peripheral blood stem cell collection in order to figure out the more effective timing for PBSC. Method: The subjects of this study were 189 patients undergoing 3 leukapheresis from January 28, 2005 to December 31,2006. Group's characteristics, checkup opinion of pre-peripheral blood on the day of harvest & outcome of PBSC were analyzed and evaluated using SAS statistics program after grouping patients as below; group 1-CD34 cell counts $<2{\times}10^6/kg$ (n=97); group $2-2{\times}10^6/kg$ ${\leq}CD34$ cell counts $<4{\times}10^6/kg$ (n=26); group 3-CD34 cell counts ${\geq}4{\times}10^6/kg$ (n=63). Results: Based on outcome of peripheral blood stem cell according to diagnosis, acute myelocytic leukemia (AML) was 65.5% at Group 1, Lymphoma was 21.7% at Group 2 and multiple myeloma (MM) was 70.8% at Group 3. There were significant differences in CD34 cell counts according to diagnosis (p=0.00004). Type of cytokine mobilization according to diagnosis, Lenograsim was using 62.5% of MM & 38.2% of AML and filgrastim is using 22.0% of AML only. Circular peripheral blood CD34 cell counts prior to harvest was $258.1/{\mu}L$ at Group 3 which was much higher comparing to Group 1 ($10.5/{\mu}L$) and Group 2 ($39.9/{\mu}L$) (p<0.001). TNC counts of collected peripheral blood stem cell was $15.36{\times}10^6/kg$ at Group 3 and it's much higher than Group 2 ($13.16{\times}10^6/kg$) and Group 1 ($12.36{\times}10^6/kg$) (p=0.083). There was no significant difference in MNC counts inbetween 3 groups. Conclusions: Circular peripheral blood CD34+ cell counts prior to harvest was much higher at Group 3 than Group 1 and Group 2. Therefore, the number of CD34+ cells on the day of harvest can be used as an accurate predictor for peripheral blood stem cell.