• 한국유전체학회:학술대회논문집
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• 한국유전체학회 2003년도 The 12th Korea Genome Conference
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• pp.53.2-53.2
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• 2003

• Molecules and Cells
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• 제20권1호
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• pp.57-68
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• 2005

Murine erythroleukemia (MEL) cells are widely used to study erythroid differentiation thanks to their ability to terminally differentiate in vitro in response to chemical induction. At the molecular level, not much is known of their terminal differentiation apart from activation of adult-type globin gene expression. We examined changes in gene expression during the terminal differentiation of these cells using microarray-based technology. We identified 180 genes whose expression changed significantly during differentiation. The microarray data were analyzed by hierarchical and k-means clustering and confirmed by semi-quantitative RT-PCR. We identified several genes including H1f0, Bnip3, Mgl2, ST7L, and Cbll1 that could be useful markers for erythropoiesis. These genetic markers should be a valuable resource both as potential regulators in functional studies of erythroid differentiation, and as straightforward cell type markers.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권5호
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• pp.444-450
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• 2005

Epidermal growth factor (EGF) activates many intracellular effector molecules, which subsequently influence the expression levels of many genes involved in cell growth, apoptosis and signal transduction, etc. In this study, the early response of gene expressions due to EGF treatment was monitored using oligonucleotide DNA microarrays in rat schwannoma cell lines. An immunoblotting experiment showed the successful activation of EGF receptors and an effector protein, STAT5, due to EGF treatment. The microarray study showed that 35 genes were significantly induced and 2 were repressed within 60 min after the treatment. The list of induced genes included early growth response 1, suppressor of cytokine signaling 3, c-fos, interferon regulatory factor 1 and early growth response 2, etc. According to the microarray data, six of these were induced by more than 10-fold, and showed at least two different induction patterns, indicating complicated regulatory mechanisms in the EGF signal transduction.

• Environmental Analysis Health and Toxicology
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• 제20권2호
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• pp.187-194
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• 2005

Octachlorostyrene (OCS) is a primarily concerning chemical in many countries because of its persistent and bioaccumulative properties in the environment. OCS is not commercially manufactured or used but it may be produced during incineration or chemical synthetic processes involving chlorinated compounds. There are several reports that OCS was found in the waters, sediments, fish, mussels, and also in human tissues. However, systematic studies on the OCS toxicities are scarce in literature. In this study, we tried to get the gene expression data using medaka DNA chip to identify biomarkers of OCS exposure. Medaka (Oryzias latipes.) was exposed to OCS 1 ppm for 2 days and 10 days, respectively. Total RNA was extracted and purified by guanidine thiocyanate method and the Cy3- and Cy5-labelled cDNAs produced by reverse trancription of the RNA were hybridized to medaka microarray. As results, eighty five genes were found to be down-or up regulated by OCS. Some of the genes were listed and confirmed by real-time PCR.

• 한국생물정보학회:학술대회논문집
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• 한국생물정보시스템생물학회 2004년도 The 3rd Annual Conference for The Korean Society for Bioinformatics Association of Asian Societies for Bioinformatics 2004 Symposium
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• pp.124-130
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• 2004

Microarray expression datasets are incessantly cumulated with the aid of recent technological advances. One of the first steps for analyzing these data under various experimental conditions is determining differentially expressed genes (DEGs) in each condition. Reasonable choices of thresholds for determining differentially expressed genes are used for the next -step-analysis with suitable statistical significances. We present a model for identifying DEGs using pathway information based on the global connectivity structure. Pathway information can be regarded as a collection of biological knowledge, thus we are tying to determine the optimal threshold so that the consequential connectivity structure can be the most compatible with the existing pathway information. The significant feature of our model is that it uses established knowledge as a reference to determine the direction of analyzing microarray dataset. In the most of previous work, only intrinsic information in the miroarray is used for the identifying DEGs. We hope that our proposed method could contribute to construct biologically meaningful network structure from microarray datasets.

• 한국잠사학회:학술대회논문집
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• 한국잠사학회 2003년도 제46회 춘계 학술연구 발표회
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• pp.47-48
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• 2003

The development of cDNA microarray has permitted the analysis of thousands of genes simultaneously. cDNA microarray has been used to analyze gene expression profiles during developmental stage in both single and multicellular organisms. Two significant factors contributing to the limitation of the development of cDNA microarray in the Bombyx mori are the shortage of accessible repositories of cDNA clones and ESTs and the relative scarcity of facilities to produce microarrays and analyze the data generated. (omitted)

• 한국생물정보학회:학술대회논문집
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• 한국생물정보시스템생물학회 2000년도 International Symposium on Bioinformatics
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• pp.41-44
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• 2000

With the advent of DNA microarray and "chip" technologies, gene expression in an organism can be monitored on a genomic scale, allowing the transcription levels of many genes to be measured simultaneously. Functional interpretation of massive expression data and linking such data to DNA sequences have become the new challenges to bioinformatics. I will us yeast cell cycle expression data analysis as an example to demonstrate how special database and computational methods may be used for extracting functional information, I will also briefly describe a novel clustering algorithm which has been applied to the cell cycle data.

• 한국생물정보학회:학술대회논문집
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• 한국생물정보시스템생물학회 2005년도 BIOINFO 2005
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• pp.357-360
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• 2005

In this paper we consider the well-known semiparametric proportional hazards (PH) models for survival analysis. These models are usually used with few covariates and many observations (subjects). But, for a typical setting of gene expression data from DNA microarray, we need to consider the case where the number of covariates p exceeds the number of samples n. For a given vector of response values which are times to event (death or censored times) and p gene expressions (covariates), we address the issue of how to reduce the dimension by selecting the significant genes. This approach enable us to estimate the survival curve when n < < p. In our approach, rather than fixing the number of selected genes, we will assign a prior distribution to this number. The approach creates additional flexibility by allowing the imposition of constraints, such as bounding the dimension via a prior, which in effect works as a penalty. To implement our methodology, we use a Markov Chain Monte Carlo (MCMC) method. We demonstrate the use of the methodology to diffuse large B-cell lymphoma (DLBCL) complementary DNA(cDNA) data.

• Journal of Applied Biological Chemistry
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• 제55권4호
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• pp.227-234
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• 2012

유채 종자 성숙단계별 변화하는 종자의 특성을 살펴본 결과, 개화 후 25일된 미성숙 종자에서 지방산 생성이 관찰되기 시작하였으며, 개화 후 35일된 미성숙 종자에서 지방산 생성이 거의 최고치에 달하는 것을 관찰하였으며, 이 때 백립중이 406 mg으로 가장 무거웠다. 유채 300k Microarray를 이용하여 유채 종자 성숙단계별 발현되는 유전자의 발현양상을 살펴보았다. 유채 300k Microarray는 NCBI에 등록되어 있는 543,448개의 ESTs와 780개의 cDNA정보를 군집 분석하여 80,696개의 유전자정보를 얻어 제작되었다. 개화 후 10, 25, 그리고 35일된 종자에서 total RNA를 분리하여 유채 300k Microarray 실험을 수행한 결과, 약 7,000개의 유전자에 해당하는 8.5%가 잎에 비해 종자(25DAF)에서 발현 양이 2배 이상 증가됨을 알 수 있었고, 10배 이상 증가하는 유전자 비율도 0.4%에 해당하였다. 종자 특이 발현 유전자의 발현양상을 보면, 초기에는 저장 및 세포분화 관련 유전자들의 발현 양이 높게 나타난 반면, 후기에는 지방산 대사 관련 유전자를 포함한 에너지 축적 관련 유전자들의 발현 양이 높게 나타나는 것을 관찰 할 수 있었으며, reverse transcriptase-polymerase chain reaction을 통해서 이를 확인하였다. 본 실험 결과는 종자 특이 발현 프로모터를 발굴하거나 특정 대사 기작 연구에 관여하는 유전자 발현 양상을 광범위하게 살펴봄으로써 좀 더 심도 있는 연구를 할 수 있는 기초자료를 제공하는데 많은 도움이 될 거라 사료된다.

• 생명과학회지
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• 제22권11호
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• pp.1552-1557
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• 2012

Pipernonaline은 후추나무과에 속하는 필발(Piper longum Linn.)의 유도체로서 전립선 암세포에 대한 항암활성이 보고되고 있다. 하지만 실제 암세포 내에서 생물학적 정보를 가진 수 많은 유전자들에 대한 발현이 어떻게 이루어지고 있는지 알려진 바가 없다. 본 연구에 사용된 microarray 분석은 동시에 수 만개 이상의 유전자 발현양상을 한번에 관찰할 수 있는 기술로서 특정 질병의 유전학적 특성과 기전 연구를 더 광범위하게 연구 할 수 있는 기술이다. 본 연구에서는 전립선 암세포인 PC-3 세포에 pipernonaline을 처리하여 cDNA microarray를 실시하였다. 이후, DAVID database를 이용하여 gene ontology의 Biological Process를 분석하여 세포사멸과 세포주기, 세포성장 및 증식에 관련된 유전자들을 우선적으로 분석하였다. 그 결과, 세포주기관련 256개, 세포사멸관련 197개, 세포성장 및 증식관련에 154개의 유전자가 확인 되었다. 이러한 결과는 pipernonaline은 전립선 암세포 내에 존재하는 생물학적 신호전달체계에 관련된 유전자 발현을 조절함으로써 항암활성을 나타내 것을 알 수 있었고, 이후 이러한 microarray의 추가적인 분석은 암세포 내 새로운 유전자의 탐색 및 메커니즘을 규명하는데 유용하게 사용할 수 있을 것으로 사료된다.