• Journal of Microbiology and Biotechnology
• /
• 제24권12호
• /
• pp.1654-1663
• /
• 2014

To examine the effect of tumor suppressor protein p53 on the antitumor activity of 2-methoxyestradiol (2-MeO-$E_2$), 2-MeO-$E_2$-induced cell cycle changes and apoptotic events were compared between the human colon carcinoma cell lines HCT116 ($p53^{+/+}$) and HCT116 ($p53^{-/-}$). When both cell types were exposed to 2-MeO-$E_2$, a reduction in the cell viability and an enhancement in the proportions of $G_2/M$ cells and apoptotic sub-$G_1$ cells commonly occurred dose-dependently. These 2-MeO-$E_2$-induced cellular changes, except for $G_2/M$ arrest, appeared to be more apparent in the presence of p53. Immunofluorescence microscopic analysis using anti-${\alpha}$-tubulin and anti-lamin B2 antibodies revealed that after 2-MeO-$E_2$ treatment, impaired mitotic spindle network and prometaphase arrest occurred similarly in both cell types. Following 2-MeO-$E_2$ treatment, only HCT116 ($p53^{+/+}$) cells exhibited an enhancement in the levels of p53, p-p53 (Ser-15), $p21^{WAF1/CIP1}$, and Bax; however, the Bak level remained relatively constant in both cell types, and the Bcl-2 level decreased only in HCT116 ($p53^{+/+}$) cells. Additionally, mitochondrial apoptotic events, including the activation of Bak and Bax, loss of ${\Delta}{\psi}m$, activation of caspase-9 and -3, and cleavage of lamin A/C, were more dominantly induced in the presence of p53. The Bak-specific and Bax-specific siRNA approaches confirmed the necessity of both Bak and Bax activations for the 2-MeO-$E_2$-induced apoptosis in HCT116 cells. These results show that among 2-MeO-$E_2$-induced apoptotic events, including prometaphase arrest, up-regulation of Bax level, down-regulation of Bcl-2 level, activation of both Bak and Bax, and mitochondria-dependent caspase activation, the modulation of Bax and Bcl-2 levels is the target of the pro-apoptotic action of p53.

• 한국통신학회논문지
• /
• 제41권4호
• /
• pp.395-403
• /
• 2016

본 논문은 이기종 네트워크(heterogeneous networks: HetNet)를 위한 다중 셀 검출 방안을 제안한다. 이기종 네트워크에서 여러 셀을 동시에 검출 시 모든 셀로부터의 채널 정보를 획득하는 것은 어렵기 때문에 채널 정보를 필요로 하지 않는 비동기(non-coherent) 검출 방식이 선호된다. 본 논문에서는 가중치 벡터를 사용하는 비동기 기반 단일 셀 검출 기법을 제안하고, 이를 이용한 순차적 간섭 제거 기반 다중 셀 방안을 고안한다. 셀 검출 능력 향상을 위해 가중치 벡터는 무선 채널이 갖는 일반적 성질을 반영하여 설계되었다. 또한 제안된 단일 셀 검출 방안의 성능이 각 채널 환경별 최적 가중치 벡터 근처에서 둔감하게 변하는 성질을 바탕으로 다양한 채널 환경 및 신호 대 잡음비 영역에서 최적 성능에 근접한 universal 가중치 벡터도 제안되었다. 모의실험 결과 제안된 다중 셀 검출 방안은 향상된 단일 셀 검출 능력을 통해 기존 방식 대비 좀 더 정확히 셀을 검출할 수 있고, 검출된 셀로부터의 신호를 수신 신호에서 제거함으로써 나머지 셀을 효과적으로 검출할 수 있음을 확인하였다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• 제27권6호
• /
• pp.491-497
• /
• 2001

Polymethylmethacrylate(PMMA) is currently commonly used material for the reconstruction of bone defects and fixation of joint prosthetics following congenital and acquired causes. Although PMMA has widespread use, it does not possess the ideal mechanical characteristics with osteoconductivity and osteoinductivity required. In order to overcome these problem, addition of bovine bone drived defatting demineralized bone(BDB) powders to a PMMA bone cement was done for improvement of physical property and bone forming characteristics of composite. In order to investigate the influence of BDB reinforcement on the PMMA, we measured physical property of compressive, tensile, flexural strength, and scanning electron microscopic examinations. The results were obtained as follows: 1. The PMMA forms a solid cellular matrix with open cells about $100{\mu}m$ in variable size and incorporating BDB. BDB aggregates inside the cells form a porous network that is accessible from the outer surface. 2. The physical properties were compressive strength of mean $22.74{\pm}1.69MPa$, tensile strength of mean $22.74{\pm}1.69MPa$, flexural strength of mean $77.53{\pm}6.93MPa$. Scanning electron microscopic examinations were revealed that there was DBD particles form a highly porous agglomerates. BDB can be added PMMA in the form of dried powders, the composites are applicable as bone substitutes. BDB and PMMA mixture is shown to produce a class of composites that due to their microstructure and improved mechanical properties may be suitable for application as bone subsitutes. The mechanical and material properties of the BDB-PMMA bone substitute composites are competitive with those properties of a porous ceramic matrix of other hydroxyapatite and with those of natural bones.

• IMMUNE NETWORK
• /
• 제6권4호
• /
• pp.192-198
• /
• 2006

Background: Investigating strategy to enhance efficiency of gene transfer via adenovirus is critical to sustain gene expression in targeted cells or tissues to regulate immune responses. However, the use of adenovirus as a gene delivery method has been limited by the native tropism of the virus. In this study, the critical parameter is to improve the efficient binding of viral particles to the plasma membrane prior to cellular uptake. Methods: Human immunodeficiency virus (HIV-1) trans-acting activator of transcription (TAT), a protein transduction domain, was fused to the ectodomain of the coxsackie-adenovirus receptor (CAR). The CAR-TAT protein was produced from a Drosophila Schneider 2 cells (S2) transfected with CAR-TAT genes. The function of CARTAT was analyzed the efficiency of adenoviral gene transfer by flow cytometry, and then immunizing AdVGFP with CAR-TAT was transduced on dendritic cells (DCs). Results: S2 transfectants secreting CAR-TAT fusion protein has been stable over a period of 6 months and its expression was verified by western blot. Addition of CAR-TAT induced higher transduction efficiency for AdVGFP at every MOI tested. When mice were vaccinated with DC of which adenoviral transduction was mediated by CAR-TAT, the number of IFN-${\gamma}$ secreting T-cells was increased as compared with those DCs transduced without CAR-TAT. Conclusion: Our data provide evidence that CAR-TAT fusion protein enhances adenoviral transduction and immunogenecity of transgenes on DCs and may influence on the development of adenoviral-mediated anti-tumor immunotherapy.

• IMMUNE NETWORK
• /
• 제3권2호
• /
• pp.136-144
• /
• 2003

Oral administration of antigen has long been considered as a promising alternative for the treatment of chronic autoimmune diseases including rheumatoid arthritis (RA), and oral application of type II collagen (CII) has been proven to improve pathogenic symptoms in RA patients without problematic side effects. To further current understandings about the immune suppression mechanisms mediated by orally administered antigens, we examined the changes in IgG subtypes, T-cell proliferative response, and proportion of interleukin (IL)-10 producing Th subsets in a time course study of collagen induced arthritis (CIA) animal models. We found that joint inflammation in CIA mouse peaked at 5 weeks after first immunization with CII, which was significantly subdued in mice pre-treated by repeated oral administration of CII. Orally tolerized mice also showed increase in their serum level of IgG1, while the level of IgG2a was decreased. T-cell proliferation upon CII stimulation was also suppressed in lymph nodes of mice given oral administration of CII compared to non-tolerized controls. When cultured in vitro in the presence of CII, T-cells isolated from orally tolerized mice presented higher proportion of $CD4^+IL-10^+$ subsets compared to non-tolerized controls. Interestingly, such increase in IL-10 producing cells were obvious first in Peyer's patch, then by 5 weeks after immunization, in mesenteric lymph node and spleen instead. This result indicates that a particular subset of T-cells with immune suppressive functions might have migrated from the original contact site with CII to inflamed joints via peripheral blood after 5 weeks post immunization.

• 전자공학회논문지CI
• /
• 제46권1호
• /
• pp.88-95
• /
• 2009

본 논문에서는 고성능 네트워크 응용에서 사용하기 위한 트래픽 패턴 매칭 하드웨어를 제안한다. 제안하는 트래픽 패턴 매칭 하드웨어는 고속 망에서 다양한 종류의 정보 유출이나 침입을 차단하기 위한 콘텐츠 보안 시스템에서 사용 할 목적으로 설계되었다. 제안하는 하드웨어는 헤더 검색부와 스트링 패턴 매칭부로 구성되었다. 헤더 검색부의 하드웨어 구현에는, 흔히 TCAM(Ternary CAM) 구현이 사용되지만 하드웨어나 메모리 비용과 전력 소모 면에서 비효율적이므로, 본 논문에서는 비교기 배열과 HiCuts 트리에 기반을 둔 구현 기법을 채택하고 이를 수정하여 적용하였다. Xilinx FPGA XC4VSX55을 사용한 구현에서, 제안된 설계는 TCAM 구현에 비하여 FPGA 슬라이스 사용을 약 26%까지 그리고 블록 RAM의 사용을 약 58%까지 절약할 수 있었다. 스트링 패턴 매칭부의 설계에서는 하드웨어 면에서 효율적이며, 충돌 발생률을 감소시킬 수 있도록 구성을 바꿔 전력 소모를 감소시킬 수 있는 셀룰러 오토마타형 해싱 모듈을 설계하여 사용하였다.

• Molecules and Cells
• /
• 제37권7호
• /
• pp.547-553
• /
• 2014

Glioblastoma multiforme (GBM) is one of the most common brain malignancies and has a very poor prognosis. Recent evidence suggests that the presence of cancer stem cells (CSC) in GBM and the rare CSC subpopulation that is resistant to chemotherapy may be responsible for the treatment failure and unfavorable prognosis of GBM. A garlic-derived compound, Z-ajoene, has shown a range of biological activities, including anti-proliferative effects on several cancers. Here, we demonstrated for the first time that Z-ajoene specifically inhibits the growth of the GBM CSC population. CSC sphere-forming inhibition was achieved at a concentration that did not exhibit a cytotoxic effect in regular cell culture conditions. The specificity of this inhibitory effect on the CSC population was confirmed by detecting CSC cell surface marker CD133 expression and biochemical marker ALDH activity. In addition, stem cell-related mRNA profiling and real-time PCR revealed the differential expression of CSC-specific genes, including Notch, Wnt, and Hedgehog, upon treatment with Z-ajoene. A proteomic approach, i.e., reverse-phase protein array (RPPA) and Western blot analysis, showed decreased SMAD4, p-AKT, 14.3.3 and FOXO3A expression. The protein interaction map (http://string-db.org/) of the identified molecules suggested that the AKT, ERK/p38 and $TGF{\beta}$ signaling pathways are key mediators of Z-ajoene's action, which affects the transcriptional network that includes FOXO3A. These biological and bioinformatic analyses collectively demonstrate that Z-ajoene is a potential candidate for the treatment of GBM by specifically targeting GBM CSCs. We also show how this systemic approach strengthens the identification of new therapeutic agents that target CSCs.

• Molecules and Cells
• /
• 제26권6호
• /
• pp.566-575
• /
• 2008

Twenty-five chipmunk species occur in the world, of which only the Siberian chipmunk, Tamias sibiricus, inhabits Asia. To investigate mitochondrial cytochrome b sequence variations and population structure of the Siberian chipmunk in northeastern Asia, we examined mitochondrial cytochrome b sequences (1140 bp) from 3 countries. Analyses of 41 individuals from South Korea and 33 individuals from Russia and northeast China resulted in 37 haplotypes and 27 haplotypes, respectively. There were no shared haplotypes between South Korea and Russia - northeast China. Phylogenetic trees and network analysis showed 2 major maternal lineages for haplotypes, referred to as the S and R lineages. Haplotype grouping in each cluster was nearly coincident with its geographic affinity. In particular, 3 distinct groups were found that mostly clustered in the northern, central and southern parts of South Korea. Nucleotide diversity of the S lineage was twice that of lineage R. The divergence between S and R lineages was estimated to be 2.98-0.98 Myr. During the ice age, there may have been at least 2 refuges in South Korea and Russia - northeast China. The sequence variation between the S and R lineages was 11.3% (K2P), which is indicative of specific recognition in rodents. These results suggest that T. sibiricus from South Korea could be considered a separate species. However, additional information, such as details of distribution, nuclear genes data or morphology, is required to strengthen this hypothesis.

• Molecules and Cells
• /
• 제40권6호
• /
• pp.386-392
• /
• 2017

Periodontal ligament stem cells (PDLSCs) are multipotent stem cells derived from periodontium and have mesenchymal stem cell (MSC)-like characteristics. Recently, the perivascular region was recognized as the developmental origin of MSCs, which suggests the in vivo angiogenic potential of PDLSCs. In this study, we investigated whether PDLSCs could be a potential source of perivascular cells, which could contribute to in vivo angiogenesis. PDLSCs exhibited typical MSC-like characteristics such as the expression pattern of surface markers (CD29, CD44, CD73, and CD105) and differentiation potentials (osteogenic and adipogenic differentiation). Moreover, PDLSCs expressed perivascular cell markers such as NG2, ${\alpha}-smooth$ muscle actin, platelet-derived growth factor receptor ${\beta}$, and CD146. We conducted an in vivo Matrigel plug assay to confirm the in vivo angiogenic potential of PDLSCs. We could not observe significant vessel-like structures with PDLSCs alone or human umbilical vein endothelial cells (HUVECs) alone at day 7 after injection. However, when PDLSCs and HUVECs were co-injected, there were vessel-like structures containing red blood cells in the lumens, which suggested that anastomosis occurred between newly formed vessels and host circulatory system. To block the $SDF-1{\alpha}$ and CXCR4 axis between PDLSCs and HUVECs, AMD3100, a CXCR4 antagonist, was added into the Matrigel plug. After day 3 and day 7 after injection, there were no significant vessel-like structures. In conclusion, we demonstrated the perivascular characteristics of PDLSCs and their contribution to in vivo angiogenesis, which might imply potential application of PDLSCs into the neovascularization of tissue engineering and vascular diseases.

• Archives of Plastic Surgery
• /
• 제33권1호
• /
• pp.46-52
• /
• 2006

High-density micromass culture was needed to take three dimensions culture with ASCs(adipose derived stromal cells) and chondrogenesis. However, the synthetic polymer has hydrophobic character and low affinity to cells and other biomolecules. Therefore, the surface modification without changes of physical and chemical properties is necessary for more suitable condition to cells and biomolecules. This study was performed to investigate the effect of surface modification of poly (lactic-co-glycolic acid)(PLGA) scaffold by plasma treatment (P(+)) on the adhesion, proliferation and chondrogenesis of ASCs, and not plasma treatment (P(-)). ASCs were isolated from human subcutaneous adipose tissue obtained by lipectomy and liposuction. At 1 hour 30 minutes and 3days after cell seeding onto the P(-) group and the P(+) group, total DNA amount of attached and proliferated ASCs markedly increased in the P(+) group (p < 0.05). The changes of the actin under confocal microscope were done for evaluation of cellular affinity, at 1 hour 30 minutes, the shape of the cells was spherical form in all group. At 3rd day, the shape of the cells was fiber network form and finely arranged in P(+) group rather than in P(-) group. RT-PCR analysis of cartilage-specific type II collagen and link protein were expressed in 1, 2 weeks of induction. Amount of Glycoaminoglycan (GAG) markedly increased in P(+) group(p < 0.05). In a week, extracellular matrix was not observed in the Alcian blue and Safranin O staining. However in 2 weeks, it was observed that sulfated proteoglycan increased in P(+) group rather than in P(-) group. In conclusion, we recognized that plasma treatment of PLGA scaffold could increase the hydrophilic property of cells, and provide suitable environment for high-density micromass culture to chondrogenesis