• The Journal of Korean Academy of Prosthodontics
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• v.59 no.4
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• pp.379-394
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• 2021

Purpose. In our previous studies, application of trichloroacetic acid (TCA) to gingival fibroblasts or to canine palatal soft tissue was verified to alter the expression of several genes responsible for cell cycle progression. In order to confirm this effect in a system allowing sequential release of TCA and epidermal growth factor (EGF), expression of various cell cycle genes following the application of the agents, using hydrophobically modified glycol chitosan (HGC)-based nano-controlled release system, was explored in this study. Materials and methods. HGC-based nano-controlled release system was developed followed by loading TCA and EGF. The groups were defined as the control (CON); TCA-loaded nano-controlled release system (EXP1); TCA- and EGF- individually loaded nano-controlled release system (EXP2). At 24- and 48 hr culture, expression of 37 cell cycle genes was analyzed in human gingival fibroblasts. Correlations and the influential genes were also analyzed. Results. Numerous genes such as cyclins (CCNDs), cell division cycles (CDCs), cyclin-dependent kinases (CDKs), E2F transcription factors (E2Fs), extracellular signal-regulated kinases (ERKs) and other cell cycle genes were significantly up-regulated in EXP1 and EXP2. Also, cell cycle arrest genes of E2F4, E2F5, and GADD45G were up-regulated but another cell cycle arrest gene SMAD4 was down-regulated. From the multiple regression analysis, CCNA2, CDK4, and ANAPC4 were determined as the most influential factors on the expression of ERK genes. Conclusion. Application of TCA and EGF, using the HGC-based nano-controlled sequential release system significantly up-regulated various cell cycle progression genes, leading to the possibility of regenerating oral soft tissue via application of the proposed system.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.5
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• pp.383-393
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• 2008

Purpose: Cancer specific killing can be achieved by therapeutic gene activated by cancer specific promotor. Expression of sodium iodide symporter (NIS) gene causes transportation and concentration of iodide into the cell, therefore radioiodine treatment after NIS gene transfer to cancer cell could be a form of radionuclide gene therapy. luciferase (Luc) gene transfected cancer cell can be monitored by in vivo optical imaging after D-luciferin injection. Aims of the study are to make vector with both therapeutic NIS gene driven by AFP promoter and reporter Luc gene driven by CMV promoter, to perform hepatocellular carcinoma specific radiodiodine gene therapy by the vector, and assessment of the therapy effect by optical imaging using luciferase expression. Materials and Methods: A Vector with AFP promoter driven NIS gene and CMV promoter driven Luc gene (AFP-NIS-CMV-Luc) was constructed. Liver cancer cell (HepG2, Huh-7) and non liver cancer cell (HCT-15) were transfected with the vector using liposome. Expression of the NIS gene at mRNA level was elucidated by RT-PCR. Radioiodide uptake, perchlorate blockade, and washout tests were performed and bioluminescence also measured by luminometer in these cells. In vitro clonogenic assay with 1-131 was performed. In vivo nuclear imaging was obtained with gamma camera after 1-131 intraperitoneal injection. Results: A Vector with AFP-NIS-CMV-Luc was constructed and successfully transfected into HepG2, Huh-7 and HCT-15 cells. HepG2 and Huh-7 cells with AFP-NIS-CMV-Luc gene showed higher iodide uptake than non transfected cells and the higher iodide uptake was totally blocked by addition of perchlorate. HCT-15 cell did not showed any change of iodide uptake by the gene transfection. Transfected cells had higher light output than control cells. In vitro clonogenic assay, transfected HepG2 and Huh-7 cells showed lower colony count than non transfected HepG2 and Huh-7 cells, but transfected HCT-15 cell did not showed any difference than non transfected HCT-15 cell. Number of Huh-7 cells with AFP-NIS-CMV-Luc gene transfection was positively correlated with radioidine accumulation and luciferase activity. In vivo nuclear imaging with 1-131 was successful in AFP-NIS-CMV-Luc gene transfected Huh-7 cell xenograft on nude mouse. Conclusion: A Vector with AFP promoter driven NIS and CMV promoter driven Luc gene was constructed. Transfection of the vector showed liver cancer cell specific enhancement of 1-131 cytotoxicity by AFP promoter, and the effect of the radioiodine therapy can be successfully assessed by non-invasive luminescence measurement.

• Korean Journal of Microbiology
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• v.46 no.2
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• pp.113-121
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• 2010

Bacillus subtilis PhoP-PhoR two-component system (TCS) senses phosphate deficiency conditions, and then controls expression of the Pho regulon to prolong survival. The sensor histidine kinase, PhoR, is autophosphorylated and transfers the phosphate to the response regulator, PhoP. Phosphorylated PhoP (PhoP~P) binds to repeated 6-bp consensus PhoP binding sequences of Pho regulon promoters and activates or represses gene expression. Pho signal transduction systems are part of interconnected signal transduction network involving at least three TCSs (PhoP-PhoR, ResD-ResE TCS, SpoOA phosphorelay), a global carbon metabolism regulator (CcpA), and transition state regulators (AbrB, ScoC). In addition, PhoP-PhoR TCS is cross related with YycF-YycG TCS by cross-regulation. While indescribable progress has been made in understanding phosphate deficiency stress response through refined expression of the Pho regulon in the recent past years, many important questions still remain. Solving these questions may provide important information for application study using B. subtilis.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07b
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• pp.286-288
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• 2005

MicroRNA (miRNA)는 작은 크기의 RNA분자로서 동식물의 유전자 발현 과점을 직접적으로 조절하는 인자로 알려져 있다. MiRNA는 보통 목표 유전자의 3'-UTR 영역에 상보성을 갖고 결합함으로써 작용하며 특히 miRNA의 5'부분의 8 nt 정도가 seed로서 중요하다고 알려져 있다. 반면 최근의 연구에 따르면 seed 부분의 서열의 조성 및 양상이 변화함에 따라 특이도가 결정됨을 알 수 있지만 기존의 컴퓨터를 이용한 miRNA 목표 유전자 예측 방법들은 이러한 정보를 활용하지 못한다. 본 논문에서는 열역학적인 수치와 서열의 조성뿐 아니라 miRNA:mRNA pair의 위치에 기반한 정보들을 학습에 자질로서 포함하여 목표 유전자를 예측한다. 그 결과는 위치 기반 자질이 학습 성능 향상에 중요하게 기여함을 보여준다.

• The Korean Journal of Zoology
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• v.37 no.2
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• pp.240-248
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• 1994

골격근 세포는 미분화 단핵 근원세포로부터 신장과 융합을 거쳐 다핵 횡문근섬유로 분화되어 가며 동시에 근특이 유전자의 발현이 선택적으로 일어난다. 본 연구에서는 계배 배양 근원세포의 분화동안 유전자 발현 조절 양상에 대한 연구를 위해, 계배 근원세포를 72시간 배양한 근섬유로부터 CDNA 라이브러리를 제작하였다. 이 cDNA 라이브러리를 미분화 단핵 근원세포(배양 36시간)와 분화된 다핵 근섬유(배양 72시간)의 poly(A)+ RNA 주형에서 합성된 [32P〕cDNA를 Probe로 사용한 differential plaque hybridization 방법으로 스크리닝하였다 분화된 다핵 근섬유 CDNA probe에 강한게 흔성화되는 CDNA clone을 선별하여 클로닝하였다. 선별한 CDNA clone 들 중 하나는 약 1.3 Kb 크기의 삽입절편을 갖고 있는 것으로 나타났고, 이 CDNA를 probe로 사용하여 northern blotting 한 결과, 이 CDNA엑 대한 유전자는 미분화 단핵 근원세포에서 분화된 다핵 근섬유로 분화가 진행됨에 따라 유전자 산물인 RNA 양이 증가되는 것으로 나타났다 또한 이 1.3 Kb CDNA에 대한 RNA의 크기는 약 2 7 Kb로 확인되었다.

• Proceedings of the Korea Contents Association Conference
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• 2012.05a
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• pp.355-356
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• 2012

후성유전은 DNA 염기 서열이 변화하지 않고 DNA의 메틸화(methyaltion) 및 히스톤 단백질의 변형(modification)등의 후천적 과정에 의해 유전자 발현이 조절되는 현상이다. 특히 DNA 메틸화 정도에 대한 패턴 분석은 후성유전을 이해하는 중요한 접근방법중 하나이다. DNA 메틸화 패턴 분석을 위해 발생에 관련된 123개 유전자들의 -5000bp ~ +200bp사이에 있는 DNA 염기 서열 정보를 추출하였다. 추출한 염기 서열 정보를 기반으로 기존에 알려진 메틸화 경향성 모티프와 메틸화 저항성 모티프를 모니터링 함으로써 발생관련 유전자들의 메틸화 모티프 패턴을 분석하였다. 결과적으로 메틸화 저항 모티프만이 발견되었고 따라서 메틸화 저항 모티프 패턴과 발생관련 유전자들의 상관관계를 분석하였다.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 1997.10a
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• pp.5-12
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• 1997

외래 유전자를 이식하여 형질전환동물을 생산하는 방법은 현재 약 3가지 정도가 실제 이용되고 있다. 현재 가장 많이 사용되고 있는 방법으로는 DNA 미세주입법인데 생쥐와 비교하여 다른 동물에서의 형질전환효율은 상당히 낮은 것으로 나타나 형질전환가축의 생산을 위해서는 많은 비용과 시설 및 노동이 필요하여 실용성에 문제를 갖고 있다. 각 가축에 적합한 DNA 미세주입 조건을 확립시키고 형질전환동물의 생산효율을 높이는 연구가 필요하다. 가축에서 형질전환기술이 실제로 응용되고 있는 분야로는 대량생산이 어려운 의약품을 형질전환가축의 젖으로 합성 분비시키게 함으로써 생리적으로 활성이 있는 의약품의 대량생산이 가능할 것으로 예상된다. Growth Hormone이나 Growth Factor들을 이용한 성장과 관련된 형질전환가축의 기술은 예상했던 것보다 큰 성과는 없었는데 이식 유전자의 과잉발현으로 인한 부작용으로 실용화될 수 없었다. 그러므로 형질전환동물의 실용화를 위해서는 효율적인 유전자 이식방법의 개발과 이식 유전자의 발현으로 인한 부작용을 최소화하면서 좋은 표현형을 얻을 수 있도록 이식유전자의 발현을 인위적으로 조절할 수 있는 regulatory system의 개발과 가축의 경제형질에 관여하는 유전자의 식별이 필요하다.

• Development and Reproduction
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• v.15 no.2
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• pp.159-166
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• 2011

Simazine (6-chloro-N,N'-diethyl-1,3,5-triazine-2,4-diamine) is a triazine herbicide that has been applied worldwide including Korea for agricultural purposes. Simazine is the second most commonly detected pesticide in surfaceand ground-water in the United States, Europe and Australia. It has been shown that simazine is a potent endocrine disruptor in wildlife and laboratory animals. Although many endocrine disruptors can induce apoptosis in various types of cells, the effects of simazine on apoptosis and on the expression of Bcl-2 family genes are not known. Also it is unknown the effect of simazine on the expression of steroidogenesis-regulating genes in testicular cells. In this study, we investigated the effect of simazine on the expression levels of apoptosis- and steroidogenesis-regulating genes in testicular cells. We found that a low concentration of simazine can alter the mRNA expression levels of steroidogenesis-related genes and Bcl-2 family genes in mouse Sertoli cells and rat Leydig cells. Thus, our results suggest that simazine can disturb normal testicular development and reproductive function by altering the expression of genes that are critical for the regulation of apoptosis and steroidogenesis.

• Journal of Plant Biotechnology
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• v.38 no.4
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• pp.241-250
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• 2011

The most part of vegetable oils is accumulated as storage lipid, triacylglycerol (TAG) in seed and used as energy source when seed is germinated. It is also used as essential fatty acids and energy source for human and animal. Recently, vegetable oils have been more and more an important resource because of the increasing demand of vegetable oils for cooking and industrial uses for bio-diesel and industrial feedstock. In order to increase vegetable oils using biotechnology, over-expressing or repressing the regulatory genes involved in the flow of carbon into lipid biosynthesis is critical during seed development. In this review, we described candidate genes may influence oil amount and investigate their potential for oil increase. Genes involved in the regulation from biosynthesis of fatty acids to the accumulation oils in seed can be classified as follows: First, genes play a role for synthesis precursor molecules for TAG. Second, genes participate in fatty acid biosynthesis and TAG assembly. Lastly, genes encodes transcription factors involved in seed maturation and accumulation of seed oil. Because factors/genes determining oil quantity in seed is complex as mentioned, recently regulation of transcription factors is being considered more favorable approach than manipulate multiple genes for increasing oil in transgenic plants. However, it should be figured out the problem that bad agricultural traits induced by the overexpression of transcription factor gene.

• Weed & Turfgrass Science
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• v.2 no.4
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• pp.368-375
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• 2013

Whole genome transcriptomes from Miscanthus species were sequenced and analyzed, which provided 50 different types of transcription factor (TF) involving various developmental processes or environmental stresses. Among the explored TF, WRKY gene family was the major type and one of the WRKY genes, MSIR7180_WRKY4, induced under low temperature environment was selected to investigate how the Miscanthus-originated MSIR7180_WRKY4 TF responds when exposed to low temperature in four warm-season turfgrasses (Z. matrella 'Semil', bermudagrass, St. Augustinegrass, and seashore paspalum). The MSIR7180_WRKY4 was expressed higher during low temperature period in Bermudagrass, but the expression was enhanced in St. Augustinegrass. In contrast, the gene in 'Semil' cultivar was barely expressed and relatively less expressed, but repressed gradually in seashore paspalum, which seems to allow two turfgrasses stay-green longer in the fall season. The results indicate that bermudagrass and St. Augustinegrass adapt to low temperature quickly, but relative tolerance to low or cold temperature at the molecular level needs to be further investigated at different physiological stages and the corresponding genes systematically.