• 대한골관절종양학회지
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• 제5권1호
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• pp.1-8
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• 1999

A single fraction of 50 Gy extracorporeal irradiation, as a modality of limb-sparing operation, has been used to achieve tumor necrosis in osteosarcoma. Although this modality of radiation therapy preserving the mobility of a joint is commonly practiced, the precise knowledge on the radiobiological response of osteosarcoma cell has remained to be elucidated. We therefore observed whether a single high dose irradiation caused apoptosis in osteosarcoma cells and whether the commitment to apoptosis was associated with cell kinetics. We also investigated radiation dose response along the time course for development of apoptosis following single high dose irradiation. The morphologic change in apoptosis was observed by fluorescence with Hoechst 33258 and the degree and the fraction of cells by flow cytometry. Irradiation of osteosarcoma cells with 10, 30 and 50 Gy resulted in chromatin condensation and apoptotic body formation. The degree of apoptosis in osteosarcoma cells was $29.5{\pm}3.56%$, $39.9{\pm}4.83%$ at 24 and 48 hours after 10 Gy irradiation ; $41.1{\pm}3.93%$, $66.9{\pm}5.21%$ at 24 and 48 hours after 30 Gy irradiation ; and $48.0{\pm}3.69%$, $75.6{\pm}4.65%$ at 24 and 48 hours after 50 Gy irradiation. The fraction of cells in cell-cycle kinetic was $39.2{\pm}4.3%$ in G2/M, $22.1{\pm}4.65%$ in G1 at 24 hours after 10 Gy irradiation ; $51.0{\pm}4.3%$ in G2/M, $20.4{\pm}4.7%$ in G1 at 48 hours after 10 Gy irradiation ; $40.3{\pm}3.9%$ in G2/M, $26.1{\pm}4.7%$ in G1 at 24 hours after 30 Gy irradiation ; $59.2{\pm}3.9%$ in G2/M, $5.9{\pm}5.1%$ in G1 at 48 hours after 30 Gy irradiation ; and $44.3{\pm}4.2%$ in G2/M, $21.1{\pm}3.5%$ in G1 at 24 hours after 50 Gy irradiation. The fraction of cells at 48 hours after 50 Gy irradiation could not be observed because of irradiation induced cell death of most of cells. All values for irradiated cells showed accumulation in G2/M phase and reduction in G1 phase, irrespective of irradiation dose. The results suggest that a single fraction of high dose irradiation with 50 Gy results in accumulation of cells at G2/M phase, leading to apoptosis.

• 대한골관절종양학회지
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• 제17권1호
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• pp.23-29
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• 2011

목적: 본 연구에서는 골육종 세포내 PTEN 발현정도가 세포 성장과 트로글리타존에 대한 반응도에 미치는 영향에 대해 알아보고자 하였다. 대상 및 방법: 웨스턴 블롯 분석을 통해 트로글리타존 처리 후 PTEN 발현 정도를 관찰하였고, WST를 통해 세포 증식정도를 측정하였다. 야생형 PTEN 및 돌연변이형 PTEN 발현시키는 플라스미드 DNA를 트랜스펙션하여 PTEN 발현 정도를 측정하였다. 결과: 사람골육종 세포주 U-2OS는 트로글리타존 처리 농도 및 시간에 비례하여 증식 억제를 보였고, 세포내 PTEN 발현 정도는 트로글리타존 처리 농도에 비례하여 증가하였다. 트로글리타존을 이용하여 U-2OS세포 내 PTEN 발현을 증가시키면 세포 성장 억제와 세포사 유도가 나타났다. 또한 플라스미드 트랜스펙션에 의한 PTEN 과발현은 트로글리타존의 세포증식 억제 효과를 증가 시키며 돌연변이형 PTEN을 트랜스펙션 시키는 경우 세포증식효과는 관찰되지 않았다. 결론: 골육종 세포내 PTEN 과발현이 트로글리타존에 의한 골육종 세포의 증식 억제 및 세포사 유도와 관련 되어있음을 알 수 있으며, 세포내에 PTEN이 과발현 된 상태에서 트로글리타존의 효과가 증가됨을 알 수 있었다.

• Reproductive and Developmental Biology
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• 제35권1호
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• pp.9-15
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• 2011

The functional cardiovascular system is comprised of distinct mesoderm-derived lineages including endothelial cells, vascular smooth muscle cells and other mesenchymal cells. Recent studies in the human embryonic stem cell differentiation model have provided evidence indicating that these cell lineages are developed from the common progenitors such as hemangioblasts and cardiovascular progenitor cells. Also, the studies have suggested that these progenitors have a common primordial progenitor, which expresses KDR (human Flk-1, also known as VEGFR2, CD309). We demonstrate here that sustained activation of BMP4 (bone morphogenetic protein 4) in hESC line, CHA15 hESC results in $KDR^+$ mesoderm specific differentiation. To determine whether the $KDR^+$ population derived from hESCs enhances potential to differentiate along multipotential mesodermal lineages than undifferentiated hESCs, we analyzed the development of the mesodermal cell types in human embryonic stem cell differentiation cultures. In embryoid body (EB) differentiation culture conditions, we identified an increased expression of $KDR^+$ population from BMP4-stimulated hESC-derived EBs. After induction with additional growth factors, the $KDR^+$ population sorted from hESCs-derived EBs displays mesenchymal, endothelial and vascular smooth muscle potential in matrix-coated monolayer culture systems. The populations plated in monolayer cultures expressed increased levels of related markers and exhibit a stable/homologous phenotype in culture terms. In conclusion, we demonstrate that the $KDR^+$ population is stably isolated from CHA15 hESC-derived EBs using BMP4 and growth factors, and sorted $KDR^+$ population can be utilized to generate multipotential mesodermal progenitors in vitro, which can be further differentiated into cardiovascular specific cells.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제31권4호
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• pp.287-293
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• 2009

Long-term treatment with glucocorticoid leads to the development of osteoporosis and osteonecrosis. In contrast to the marked inhibitory effect of pharmacological doses of glucocorticoids on bone formation, the relationship between physiological concentrations of glucocorticoids and osteoprogenitor cell proliferation and phenotypes has not been elucidated yet. In addition, the effects of dexamethasone treatment on the proliferation and osteoblastic differentiation of osteoprogenitor cells are also controversial. The purpose of this study was to examine the effects of dexamethasone on the proliferation and osteoblastic differentiation of periosteal-derived cells. Periosteal-derived cells were obtained from mandibular periosteums and introduced into the cell culture. After passage 3, the cells were further cultured for 21 days in the osteogenic induction medium with different dexamethasone concentrations of 0, 10, and 100 nM. The proliferation and osteoblastic phenotypes of periosteal-derived cells were promoted in dexamethasone-treated cells than in untreated cells. Among the dexamethasone-treated cells, cell proliferation was slightly greater in 10 nM dexamethasone-treated cells than in 100 nM dexamethasone-treated cells. Histochemical staining and the bioactivity of alkaline phosphatase (ALP) were higher in 100 nM dexamethasone-treated cells than in 10 nM dexamethasone-treated cells. Similarly, von Kossa-positive mineralization nodules and calcium content were also more evident in 100 nM dexamethasone-treated cells than in 10 nM dexamethasone-treated cells. These results suggest that dexamethasone enhances the in vitro osteoblastic differentiation of periosteal-derived cells. The present study also demonstrates that higher dexamethasone concentrations reduce the in vitro proliferation of periosteal-derived cells.

• IMMUNE NETWORK
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• 제5권3호
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• pp.163-171
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• 2005

Background: To perform the successful dendritic cell-based cancer immunotherapy one of the main issues to be solved is the source of antigen for DC pulsing. Limitations occur by using auto-tumor lysate due to the difficulties obtaining enough tumor tissue(s) quantitatively as well as qualitatively. In this study the possibility of allogeneic tumor cell lysate as a DC pulsing antigen has been tested in mouse melanoma pulmonary me tastasis model. Methods: B16F10 melanoma cells $(1{\timeS}10^5/mouse)$ were inoculated intra venously into the C57BL/6 mouse. Therapeutic DCs were cultured from the bone marrow myeloid lineage cells with GM-CSF and IL-4 (1,000 U/ml each) for 7 days and pulsed with lysate of either autologous B16F10 (B-DC), allogeneic K1735 (C3H/He origin; K-DC) or CloneM3 (DBA2 origin; C-DC) melanoma cells for 18 hrs. Pulsed-DCs $(1{\times}10^6/mouse)_{[CGP1]}$ were injected i.p. twice with one week interval starting from the day 1 after tumor cell inoculation. Results: Without observable toxicity, allogeneic tumor cell lysate pulsed-DC induced the significantly better anti-tumor response (tumor scale: $2.7{\pm}0.3,\;0.7{\pm}0.3\;and\;0.3{\pm}0.2$ for saline, B-DC and C-DC treated group, respectively). Along with increased tumor specific lymphocyte proliferations, induction of IFN-${\gamma}$ secretion against both auto- and allo-tumor cell lysates was observed from the DC treated mice. (w/B16F10-lysate: $44.97{\pm}10.31,\;1787.94{\pm}131.18,\;1257.15{\pm}48.27$, w/CloneM3 lysate: 0, $1591.13{\pm}1.83,\;1460.47{\pm}86.05pg/ml$ for saline, B-DC and C-DC treated group, respectively) Natural killer cell activity was also increased in the mice treated with tumor cell lysate pulsed-DC ($8.9{\pm}_{[CGP2]}0.1,\;11.6{\pm}0.8\;and\;12.6{\pm}0.7%$ specific NK activity for saline, B-DC and C-DC treated group, respectively). Conclusion: Conclusively, promising data were obtained that allogeneic-tumor cell lysate can be used as a tumor antigen for DC-based cancer immunotherapy.

• IMMUNE NETWORK
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• 제3권4호
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• pp.310-319
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• 2003

Inflammatory mediators has been recognized as an important role in the pathogenesis of rheumatoid arthritis (RA). IL-17 is increasingly recognized as an important regulator of immune and inflammatory responses, including induction of proinflammatory cytokines and osteoclastic bone resorption. Evidence of the expression and proinflammatory activity of IL-17 has been demonstrated in RA synovium and in animal models of RA. However, the signaling pathways that regulate IL-17 production remain unknown. In the present study, we investigated the role of the phosphatidylinositol 3 kinase (PI3K)-Akt pathway in the regulation of IL-17 production in RA. PBMC were separated from RA (n=24) patients, and stimulated with various agents (anti CD3, anti CD28, PHA, ConA, IL-15). IL-17 levels were determined by sandwich ELISA and RT-PCR. The production of IL-17 was significantly increased in cells treated with anti-CD3 antibody, PHA, IL-15 or MCP-1 (P<0.05). ConA also strongly induced IL-17 production (P<0.001), whereas TNF-alpha, IL-1beta, IL-18 or TGF-beta did not. IL-17 was detected in the PBMC of patients with osteoarthritis (OA) but their expression levels were much lower than those of RA PBMC. Anti-CD3 antibody activated the PI3K-Akt pathway and activation of the PI3K-Akt pathway resulted in a pronounced augmentation of nuclear factor kappaB ($NF-{\kappa}B$). IL-17 production by activated PBMC in RA is completely or partially blocked in the presence of $NF-{\kappa}B$ inhibitor PDTC and PI3K-Akt inhibitor, wortmannin and LY294002, respectively. Whereas the inhibition of AP-1 and extracellular signal-regulated kinase (ERK)1/2 did not affect IL-17 production. These results provide new insight into that PI3K/Akt and $NF-{\kappa}B$ dependent signal transduction pathway could be involved in the overproduction of key inflammatory cytokine, IL-17 in rheumatoid arthritis.

• Molecules and Cells
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• 제38권7호
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• pp.663-668
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• 2015

hBMSCs are multipotent cells that are useful for tissue regeneration to treat degenerative diseases and others for their differentiation ability into chondrocytes, osteoblasts, adipocytes, hepatocytes and neuronal cells. In this study, biodegradable elastic hydrogels consisting of hydrophilic poly(ethylene glycol) (PEG) and hydrophobic poly(${\varepsilon}$-caprolactone) (PCL) scaffolds were evaluated for tissue engineering because of its biocompatibility and the ability to control the release of bioactive peptides. The primary cultured cells from human bone marrow are confirmed as hBMSC by immunohistochemical analysis. Mesenchymal stem cell markers (collagen type I, fibronectin, CD54, $integrin1{\beta}$, and Hu protein) were shown to be positive, while hematopoietic stem cell markers (CD14 and CD45) were shown to be negative. Three different hydrogel scaffolds with different block compositions (PEG:PCL=6:14 and 14:6 by weight) were fabricated using the salt leaching method. The hBMSCs were expanded, seeded on the scaffolds, and cultured up to 8 days under static conditions in Iscove's Modified Dulbecco's Media (IMDM). The growth of MSCs cultured on the hydrogel with PEG/PCL= 6/14 was faster than that of the others. In addition, the morphology of MSCs seemed to be normal and no cytotoxicity was found. The coating of the vascular endothelial growth factor (VEGF) containing scaffold with Matrigel slowed down the release of VEGF in vitro and promoted the angiogenesis when transplanted into BALB/c nude mice. These results suggest that hBMSCs can be supported by a biode gradable hydrogel scaffold for effective cell growth, and enhance the angiogenesis by Matrigel coating.

• 대한소아치과학회지
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• 제36권4호
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• pp.591-596
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• 2009

악골내 이소매복된 치아로 인해 유치의 만기잔존, 교합이상과 같은 교정적인 문제가 발생할 경우 그 해결책으로 주기적 관찰, 최소한의 개입, 교정적 견인, 발치, 그리고 환자 자신의 매복치아를 이용하는 자가이식술 등을 들 수 있다. 자가치아이식은 치아를 구강내의 한 위치에서 다른 발치와나 외과적으로 형성된 치조와로 이동시키는 술식으로, 치아가 교정력을 가할 수 없는 위치에 존재하거나 치아 이동에 제한이 있어 통상적인 치료가 불가능할 경우에 발거에 앞서 고려할 수 있는 방법이다. 자가치아이식은 치료기간을 단축시키고, 치근 형성이 완료되지 않은 어린 환자의 경우 이식된 새로운 위치에서 치근 형성이 이루어지며, 새로운 치조골의 형성을 유도할 수 있다. 본 증례는 하악 우측 제2소구치의 매복과 하악 우측 제2유구치의 만기잔존을 주소로 본원에 내원한 11세 여아로, 하악 우측 제2소구치의 매복의 깊이가 깊고, 방향이 교정적 견인에 불리하다는 점, 미성숙 치근 발육 상태와, 만기잔존한 유구치로 인해 공간 상실이 없다는 점 등을 고려하여 자가치아이식을 시행한 뒤, 1년간의 주기적 관찰 결과, 양호한 결과를 얻어 이에 보고하는 바이다.

• 한국발생생물학회지:발생과생식
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• 제15권1호
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• pp.41-52
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• 2011

In the present study, embryoid bodies (EBs) obtained from induced pluripotent stem cells (iPSCs) were induced to differentiate into germ lineage cells by treatment with bone morphogenetic protein 4 (BMP4) and retinoic acid (RA). The results were compared to the results for embryonic stem cells (ESCs) and multipotent spermatogonial stem cells (mSSCs) and quantified using immunocytochemical analysis of germ cell-specific markers (integrin-${\alpha}6$, GFR-${\alpha}1$, CD90/Thy1), fluorescence activating cell sorting (FACS), and real time-RT-PCR. We show that the highest levels of germ cell marker-expressing cells were obtained from groups treated with 10 ng/$m{\ell}$ BMP4 or 0.01 ${\mu}M$ RA. In the BMP4-treated group, GFR-${\alpha}1$ and CD90/Thy-1 were highly expressed in the EBs of iPSCs and ESCs compared to EBs of mSSCs. The expression of Nanog was much lower in iPSCs compared to ESCs and mSSCs. In the RA treated group, the level of GFR-${\alpha}1$ and CD90/Thy-1 expression in the EBs of mSSCs Induced pluripotent stem cells, Mouse embryonic stem cells, Multipotent spermatogonial stem cells, Germ cell lineage, Differentiation potential. was much higher than the levels found in the EBs of iPSCs and similar to the levels found in the EBs of ESCs. FACS analysis using integrin-${\alpha}6$, GFR-${\alpha}1$, CD90/Thy1 and immunocytochemistry using GFR-${\alpha}1$ antibody showed similar gene expression results. Therefore our results show that iPSC has the potential to differentiate into germ cells and suggest that a protocol optimizing germ cell induction from iPSC should be developed because of their potential usefulness in clinical applications requiring patient-specific cells.

• 생명과학회지
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• 제26권1호
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• pp.91-100
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• 2016

혈관신생의 억제는 암과 같은 신생혈관형성 질환의 치료를 위해 유용한 접근법이다. 신생혈관형성의 핵심인자인 혈관내피세포성장인자는 신생혈관형성 질환의 치료를 위한 주요한 표적이다. 그러므로, 본 연구에서는 in vitro 분석과 ex vivo 동물 실험을 통해 황금 열수추출물의 신생혈관형성 억제효과를 연구했다. 본 연구결과에서 황금 열수추출물이 혈관내피세포성장인자에 의해 자극된 혈관내피세포에 있어 세포독성 없이 세포의 이동, 침투, 관형성을 농도 의존적으로 억제하였다. 더 나아가 황금 열수추출물은 혈관내피세포성장인자에 의해 유도된 흰쥐 대동맥 주변 미세혈관 발아를 예방하였다. 본 연구결과들은 황금 열수추출물이 신생혈관형성 억제작용이 있고, 이는 혈관내피세포성장인자에 의해 유도된 혈관신생을 억제 하는 잠재적 소재가 될 수 있음을 제안한다.