• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2008년도 하계종합학술대회
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• pp.897-898
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• 2008

Array comparative genomic hybridization (aCGH) has been used to detect chromosomal regions of amplifications or deletions, which allows identification of new cancer related genes. As aCGH, a large-scale spatial data, contains significant amount of noises in its raw data, it has been an important research issue to segment genomic DNA regions to detect its true underlying copy number aberrations (CNAs). In this study, we focus on applying a segmentation method to multiple data sets. We compare two different threshold values for analyzing aCGH data with CBS method [1]. The proposed threshold values are p-value or $Q{\pm}1.5IQR$ and $Q{\pm}1.5IQR$.

• Journal of Ginseng Research
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• 제35권1호
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• pp.111-123
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• 2011

To investigate the effects of repeated immobilization-stress challenge on the the hypothalamic-pituitary-adrenal axis, the genomic transcriptome in the adrenal cortex of immobilization-stressed mouse was analyzed by using a cDNA microarray. Mice were subjected to immobilization stress for 2 h per day for 5 consecutive d. With a 4.0-fold cutoff of arbitrary criteria, the expression levels of 168 out of 41,174 genes were significantly modulated in the adrenal cortex by stress when comparing the control and experimental groups. These genes were related to apoptosis, cell cycle, immune response, inflammatory responses, and signal transduction, and thus may be used as potential targets for the development of therapeutics for chronic stress or depression. Six significant genes among these were selected for real time polymerase chain reaction analysis to confirm the change of their expression levels. The gene for phospho 1 was also further investigated because its expression showed the greatest fold-change.

• 한국환경성돌연변이발암원학회:학술대회논문집
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• 한국환경성돌연변이발암원학회 2004년도 춘계학술대회
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• pp.58-59
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• 2004

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2015년도 추계학술발표대회
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• pp.123-126
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• 2015

본 연구에서는 클라우드 컴퓨팅 환경에서 운용되는 빅데이터 처리 프로그램에 ARM과 Intel의 하드웨어 보안이 어떠한 방식으로 적용되는지 비교 및 분석한다. 비교를 위하여 클라우드 서비스 모델을 제시하고, 실제 빅데이터 처리 알고리즘을 ARM과 Intel CPU를 갖춘 기기에서 작동시켜 수행 시간을 비교하였다. 연구 결과, ARMv7의 취약점인 하드웨어 암호화 모듈과 메모리 암호화의 부재를 도출하였고, 그 대안 방안으로서 FPGA(Field Programmable Gate Array)의 사용과 그 발전 방향을 제시하였다.

• Asian Pacific Journal of Cancer Prevention
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• 제13권1호
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• pp.225-229
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• 2012

Background: Males have a higher prevalence of hepatocellular carcinoma (HCC) than females in general, but the reasons for the sex disparity are still obscure. DNA copy number alteration (CNA) is a major feature of solid tumors including HCC, but whether CNA plays a role in sex-related differences in HCC development has never been evaluated. Methods: High-resolution array comparative genomic hybridization (CGH) was used to examine 17 female and 46 male HCC patients with chronic hepatitis B virus (HBV) infection in Shanghai, China. Two-tailed Fisher's exact or ${\chi}^2$ tests was used to compare CNAs between females and males. Results: The overall frequencies and patterns of CNAs in female and male cases were similar. However, female HCC tumors presented more copy number gains compared to those in males on 1q21.3-q22 (76.5% vs. 37.0%, P = 0.009), 11q11 (35.3% vs. 0.0%, P = 0.0002) and 19q13.31-q13.32 (23.5% vs. 0.0%, P = 0.004), and loss on 16p11.2 (35.3% vs. 6.5%, P = 0.009). Relative to females, male cases had greater copy number loss on 11q11 (63.0% vs. 17.6%, P = 0.002). Further analyses showed that 11q11 gain correlated with 19q13.31-q13.32 gain (P = 0.042), 11q11 loss (P = 0.011) and 16p11.2 loss (P = 0.033), while 1q21.3-q22 gain correlated with 19q13.31-q13.32 gain (P = 0.046). Conclusions: These findings suggest that CNAs may play a role in sex-related differences in HBVassociated HCC development.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제37권6호
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• pp.550-555
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• 2011

Chromosomal loss of heterozygosity (LOH) is a common mechanism for the inactivation of tumor suppressor genes in human epithelial cancers. LOH patterns can be generated through allelotyping using polymorphic microsatellite markers; however, owing to the limited number of available microsatellite markers and the requirement for large amounts of DNA, only a modest number of microsatellite markers can be screened. Hybridization to single nucleotide polymorphism (SNP) arrays using Affymetarix GeneChip Mapping 10 K 2.0 Array is an efficient method to detect genome-wide cancer LOH. We determined the presence of LOH in oral SCCs using these arrays. DNA was extracted from tissue samples obtained from 10 patients with tongue SCCs who presented at the Hospital of Tokyo Dental College. We examined the presence of LOH in 3 of the 10 patients using these arrays. At the locus that had LOH, we examined the presence of LOH using microsatellite markers. LOH analysis using Affymetarix GeneChip Mapping 10K Array showed LOH in all patients at the 1q31.1. The LOH regions were detected and demarcated by the copy number 1 with the series of three SNP probes. LOH analysis of 1q31.1 using microsatellite markers (D1S1189, D1S2151, D1S2595) showed LOH in all 10 patients (100). Our data may suggest that a putative tumor suppressor gene is located at the 1q31.1 region. Inactivation of such a gene may play a role in tongue tumorigenesis.

• Asian Pacific Journal of Cancer Prevention
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• 제15권23호
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• pp.10299-10306
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• 2015

The esophageal squamous cell carcinoma (ESCC) is thought to develop through a multi-stage process. Epigenetic gene silencing constitutes an alternative or complementary mechanism to mutational events in tumorigenesis. Posttranscriptional regulation of human leukocyte antigen class I (HLA-I) and antigen processing machinery (APM) proteins expression may be associated with novel epigenetic modifications in cancer development. In the present study, we determined the expression levels of HLA-I antigen and APM components by immunohistochemistry. Then by a bisulfite-sequencing PCR (BSP) approach, we identified target CpG islands methylated at the gene promoter region of APM family genes in a ESCC cell line (ECa109), and further quantitative analysis of CpG site specific methylation of these genes in cases of Kazakh primary ESCCs with corresponding non-cancerous esophageal tissues using the Sequenom MassARRAY platform. Here we showed that the development of ESCCs was accompanied by partial or total loss of protein expression of HLA-B, TAP2, LMP7, tapasin and ERp57. The results demonstrated that although no statistical significance was found of global target CpG fragment methylation level sof HLA-B, TAP2, tapasin and ERp57 genes between ESCC and corresponding non-cancerous esophageal tissues, there was significant differences in the methylation level of several single sites between the two groups. Of thesse only the global methylation level of LMP7 gene target fragments was statistically higher ($0.0517{\pm}0.0357$) in Kazakh esophageal cancer than in neighboring normal tissues ($0.0380{\pm}0.0214$, p<0.05). Our results suggest that multiple CpG sites, but not methylation of every site leads to down regulation or deletion of gene expression. Only some of them result in genetic transcription, and silencing of HLA-B, ERp57, and LMP7 expression through hypermethylation of the promoters or other mechanisms may contribute to mechanisms of tumor escape from immune surveillance in Kazakh esophageal carcinogenesis.

• Genomics & Informatics
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• 제10권3호
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• pp.194-199
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• 2012

In addition to single-nucleotide polymorphisms (SNP), copy number variation (CNV) is a major component of human genetic diversity. Among many whole-genome analysis platforms, SNP arrays have been commonly used for genomewide CNV discovery. Recently, a number of CNV defining algorithms from SNP genotyping data have been developed; however, due to the fundamental limitation of SNP genotyping data for the measurement of signal intensity, there are still concerns regarding the possibility of false discovery or low sensitivity for detecting CNVs. In this study, we aimed to verify the effect of combining multiple CNV calling algorithms and set up the most reliable pipeline for CNV calling with Affymetrix Genomewide SNP 5.0 data. For this purpose, we selected the 3 most commonly used algorithms for CNV segmentation from SNP genotyping data, PennCNV, QuantiSNP; and BirdSuite. After defining the CNV loci using the 3 different algorithms, we assessed how many of them overlapped with each other, and we also validated the CNVs by genomic quantitative PCR. Through this analysis, we proposed that for reliable CNV-based genomewide association study using SNP array data, CNV calls must be performed with at least 3 different algorithms and that the CNVs consistently called from more than 2 algorithms must be used for association analysis, because they are more reliable than the CNVs called from a single algorithm. Our result will be helpful to set up the CNV analysis protocols for Affymetrix Genomewide SNP 5.0 genotyping data.

• The Korean Journal of Physiology and Pharmacology
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• 제10권5호
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• pp.263-271
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• 2006

Since astrocytes were shown to play a central role in maintaining neuronal viability both under normal conditions and during stress such as ischemia, studies of the astrocytic response to stress are essential to understand many types of brain pathology. The micro array system permitted screening of large numbers of genes in biological or pathological processes. Therefore, the gene expression patterns in the in vitro model of astrocytes following exposure to oxygen-glucose deprivation (OGD) were evaluated by using the micro array analysis. Primary astrocytic cultures were prepared from postnatal Swiss Webster mice. The cells were exposed to OGD for 4 hrs at $37^{\circ}C$ prior to cell harvesting. From the cultured cells, we isolated mRNA, synthesized cDNA, converted to biotinylated cRNA and then reacted with GeneChips. The data were normalized and analyzed using dChip and GenMAPP tools. After 4 hrs exposure to OGD, 4 genes were increased more than 2 folds and 51 genes were decreased more than 2 folds compared with the control condition. The data suggest that the OGD has general suppressive effect on the gene expression with the exception of some genes which are related with ischemic cell death directly or indirectly. These genes are mainly involved in apoptotic and protein translation pathways and gap junction component. These results suggest that microarray analysis of gene expression may be useful for screening novel molecular mediators of astrocyte response to ischemic injury and making profound understanding of the cellular mechanisms as a whole. Such a screening technique should provide insights into the molecular basis of brain disorders and help to identify potential targets for therapy.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제23권4호
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• pp.306-323
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• 2001

종양발생에서 유전자 발현을 확인하고 profile 변화를 monitor하는 것은 병리학적 변화의 원인뿐 아니라 질병탐지와 진료의 새로운 목표를 확인하기 위한 새로운 기회를 제공해준다. cDNA microarray는 수천개의 유전자 발현을 동시에 연구할 수 있는 최신의 방법으로 피부, 유방, 간을 비롯한 다른 인체장기에서는 일부 이루어졌으나 array를 이용해 타액선 종양 연구에서는 전혀 이루어지지 않았다. 인간의 타액선 세포의 악성형질전환을 조절하는 분자적 상태를 연구하기 위해 본 연구는 약 2,000개의 유전자가 print된 cDNA microarray를 이용하여 인간 타액선 도관상피세포주(HSG)와 악하선에서 기원한 미분화 선암종(SGT)간에 비교연구를 하였다. Cy3와 Cy5 dye로 각각의 세포주에서 얻은 RNA와 reciprocal hybridize시키고 GenePix 4000 scanner로 스캔하고 GenePix Pro로 분석한 후 log2로 평균발현비율을 전환시켜 최소 2배이상의 발현을 보이는 유전자를 분석대상으로 하였다. 90%이상의 유전자가 비슷한 발현을 보였으며 2배이상의 발현을 보이는 경우 HSG가 SGT에 비해 72개 유전자가, SGT가 HSG에 비해 111개의 유전자 발현이 up-regulation되어 총 10%미만의 발현차이를 보였고 반복된 hybridization 으로부터 얻은 선택된 spot의 Pearson 상관계수는 -0.85이였다. HSG에서는 6번 p 염색체에서 과발현되는 유전자가 가장 많았고, SGT에서는 11번 q 염색체에서 가장 많았는데 HSG에서는 SGT에 비해 9, 13, 17, 18, 20, 21, 22염색체에서 과발현 되는 유전자 수가 많았고, SGT에서는 HSG에 비해 2, 7, 10, 15 염색체에서 유전자 발현 증가가 관찰되었다. HSG와 SGT간의 유전 발현을 기능별로 분석한 결과 몇 가지 주요 경로가 세포악성에 관련됨을 발견하였고, 타액선 도관상피세포에서 선암종을 구별하는데 기여하는 관련된 몇종의 과다 발현된 유전자를 찾았는데 전사인자, 성장인자 및 수용기, 세포골격 및 세포외기질 단백, 세포내 신호전달조절자 및 인자, 세포표면 항원등의 그룹으로 분류할 수 있었다. 따라서 이러한 microarray를 이용한 분자학적 표지자 연구가 악성 타액선 종양 발생과정에서 큰 도움을 줄 수 있을 뿐 아니라 유전자 조절에 의한 진단, 예후, 치료에서의 정확성을 개선시킬 수 있으리라 여겨진다.