• Molecular & Cellular Toxicology
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• v.1 no.3
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• pp.209-215
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• 2005

Recently, a large number of clinical experiments have shown that exposure of organic pollutants lead to various cancers through the abnormal cell growth. Environmental pollutants, such as 2, 3, 7, 8-Tetrachloro dibenzo-p-dioxin (TCDD) and polycyclic aromatic hydrocarbons (PAHs), are carcinogen and are known to cause the cognitive disability and motor dysfunction in the developing of brain. The effects of these pollutants on neurodevelopmental disorder is well established, but the underlying mechanism(s) and similarity of gene expression profiles in human brain tumors with organic pollutants still remain unclear. In this study, we first examined the gene expression profiles in glioblastomas compared with meningioma that are kinds of primary human brain tumor by using human cDNA microarray. The results of cDNA microarray analysis revealed that 26 genes were upregulated (Z-ratio>2.0) and 14 genes were downregulated (Z-ratio<-2.0) in glioblastoma compared with meningioma. From the altered gene patterns, mitogen-activated protein kinase (MAPK) signaling related genes, such as MAP2K3, MAP3K11 and jun activated domain binding protein, and transcription factors, such as UTF2 and TF12, were upregulated in glioblastoma. Also, we tried to investigate the relation between important genes up- and down-regulated in giloblastoma and various organic pollutants. Therefore, the identification of changes in the patterns of gene expression may provide a better understanding of the molecular mechanisms involved in human primary brain tumors and of the relation between gene expression profiles and organic pollutants in brain tissue.

• Korean Journal of Microbiology
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• v.42 no.4
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• pp.319-325
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• 2006

[ $\beta$ ]-Glucans (AG) were prepared from Agaricus blazei cultured in the medium fortified with the roots of Pueraria spp. by repeated extraction with hot water, gel filtration chromatography and DEAE ion exchange chromatography. Oligosaccharides (AO) were derived from the hydrolysis of AG by an endo-$\beta$-(1$\rightarrow$6)-glucanase from Bacillus megaterium. The anti-HT-29 human colon cancer activity of AG or AO was investigated using MTT assay, apoptosis assay, cell cycle analysis, and cDNA microairay. AG and AO both inhibited proliferation and growth of HT-29 cells, and stimulated apoptosis of the cells in a dose-dependent manner. In cell cycle analysis, treating HT-29 cells with AG or AO resulted in the increase of cells in the G0 (sub-G1) and G1 phase. Especially, AO was more effective in inducing G0/G1 cell cycle arrest than AG. To screen the genes involved in the increase of apoptosis, the gene expression profile of the HT-29 cells treated with AO was examined by cDNA microarray. While several genes involved in cell cycle progression (CCND2 and CDK2) were down-regulated, many genes involved in apoptosis (TNFSF9, TNFRSF9, FADD, CASP8, BAD, CRADD, CASP9 etc), cell cycle inhibitor (CDKN2A), immune response (IL6, IL18, IL6R etc), and tumor suppressor (CEACAM1, TP53BP2, IRF1, and PHB) were up-regulated. These results suggest that AO could inhibit the proliferation and growth of HT-29 cells by G0/G1 cell cycle arrest and induction of apoptosis.

• Proceedings of the Korean Society for Bioinformatics Conference
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• 2001.10a
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• pp.45-60
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• 2001

. Mediator of transcriptional regulation is the evolutionary conserved coactivator complex that plays He central role in the integration and recruitment of diverse regulatory signals and transcription machinery to certain promoters. In yeast, each Mediator subunit is required for transcriptional regulation of a distinct group of genes. In order to decipher the mechanistic roles of Mediator proteins in regulating developmental specific gene expression, we isolated, and analyzed a multiprotein complex containing Drosophila Mediate. homologs (dMediato.). dMediato. interacts with several sequence-sperific transcription factors and basal transcription machinery, and is critical for activated transcription in response to diverse transcriptional activators. In order to elucidate the function of Mediator in metazoan development, we isolated mutants of a conserved Mediate. subunit, Drosophila Med6 (dMed6). dMed6 null homozygotes failed to pupate and died in the third larval instar. Larval mitotic cells and most imaginal discs showed severe defects in proliferation, but no apparent morphological defect was observed in other larval tissues. Clonal analysis of dMed6 mutant cells revealed that dMed6 is essential for cell viability and proliferation of most adult cell types. Drosophila cDNA microarray, quantitative RT-PCR, and in situ expression analyses of developmentally regulated genes in dMed6 mutants showed that transcriptional activation of a subset of genes involved in neuroblast proliferation in the larval brain were most affected. Our results suggest that dMed6 is required in most for transcriptional regulation of a subset of genes important for cell proliferation and metabolism.

• Proceedings of the PSK Conference
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• 2001.04a
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• pp.147.3-148
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• 2001

• BMB Reports
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• v.44 no.5
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• pp.291-297
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• 2011

Aging is one of the most complicated biological processes in all species. A number of different model organisms from yeast to monkeys have been studied to understand the aging process. Until recently, many different age-related genes and age-regulating cellular pathways, such as insulin/IGF-1-like signal, mitochondrial dysfunction, Sir2 pathway, have been identified through classical genetic studies. Parallel to genetic approaches, genome-wide approaches have provided valuable insights for the understanding of molecular mechanisms occurring during aging. Gene expression profiling analysis can measure the transcriptional alteration of multiple genes in a genome simultaneously and is widely used to elucidate the mechanisms of complex biological pathways. Here, current global gene expression profiling studies on normal aging and age-related genetic/environmental interventions in widely-used model organisms are briefly reviewed.

• The Korea Genome Conference
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• 2004.07a
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• pp.47.2-47.2
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• 2004

• The Zoological Society Korea : Newsletter
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• v.18 no.2
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• pp.21-25
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• 2001

대부분의 조직은 여러 가지 세포가 모여서 이루어지기 때문에 그 중의 어떤 특정세포에서 발현하는 물질을 분석하려면 조직을 이루고 있는 각각의 세포를 분리해내야 한다. 이렇게 순수하게 세포를 분리해내는 기술 중의 하나가 Laser Captured Microdissection (LCM)이 다. LCM의 개발로 기존에 사용되던 방법에 비하여 빠르고 간편하면서, 매우 정확하게 원하는 세포를 순수 분리해서 그 세포의 분자생물학적 또는 생화학적인 분석을 할 수 있게 되었다. LCM은 현미경으로 조직절편을 관찰하면서 원하는 세포를 낮은 에너지의 laser를 사용하여 도려내는 방법으로 조직절편 이외에도 도말된 혈액이나 자궁경부 조직, 그리고 배양된 세포를 cytocentrifugation한 후에 원하는 세포를 포획 할 수도 있다. LCM을 이용한 연구는 여러 분야에서 다양하게 진행되고 있으며, 특히 같은 조직 내에 존재하는 정상세포와 전이중인 세포, 그리고 암세포를 구분해 냄으로써 암의 전이기전 및 병인 연구에 매우 큰 공헌을 하고 있다. 이렇게 분리된 세포는 RT-PCR, LOH (loss of heterozygosity), microsatellite instability, differential gene profiling, cDNA microarray, Western blot, 2D PAGE protein analysis 등의 기법을 접목하여 연구하게 된다. 본 논단을 통하여 1996년 개발된 LCM의 원리와 이제까지 LCM을 이용한 연구 성과를 살펴보고자 한다.

• Genomics & Informatics
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• v.17 no.1
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• pp.8.1-8.10
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• 2019

Alveolar type II cells constitute a small fraction of the total lung cell mass. However, they play an important role in many cellular processes including trans-differentiation into type I cells as well as repair of lung injury in response to toxic chemicals and respiratory pathogens. Transcription factors are the regulatory proteins dynamically modulating DNA structure and gene expression. Transcription factor profiling in microarray datasets revealed that several members of AP1, ATF, $NF-{\kappa}B$, and C/EBP families involved in diverse responses were expressed in mouse lung type II cells. A transcriptional factor signature consisting of Cebpa, Srebf1, Stat3, Klf5, and Elf3 was identified in lung type II cells, Sox9+ pluripotent lung stem cells as well as in mouse lung development. Identification of the transcription factor profile in mouse lung type II cells will serve as a useful resource and facilitate the integrated analysis of signal transduction pathways and specific gene targets in a variety of physiological conditions.

• Journal of Pharmacopuncture
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• v.16 no.3
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• pp.30-38
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• 2013

Objectives: Modified regular ginseng extract (MRGX) has stronger anti-cancer activity-possessing gensenoside profiles. Methods: To investigate changes in gene expression in the MRGX-treated lung cancer cells (A549), we examined genomic data with cDNA microarray results. After completing the gene-ontology-based analysis, we grouped the genes into up-and down-regulated profiles and into ontology-related regulated genes and proteins through their interaction network. Results: One hundred nine proteins that were up- and down-regulated by MRGX were queried by using IPA. IL8, MMP7 and PLAUR and were found to play a major role in the anti-cancer activity in MRGX-treated lung cancer cells. These results were validated using a Western blot analysis and a semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) analysis. Conclusions: Most MRGX-responsive genes are up-regulated transiently in A549 cells, but down-regulated in a sustained manner in lung cancer cells.

• Molecular & Cellular Toxicology
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• v.2 no.4
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• pp.273-278
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• 2006

95 squamous cell lung carcinoma samples (normal tissue: 40 samples, tumor: 55 samples) were analyzed with 8 K cDNA microarray. 1-way ANOVA test was employed to select differentially expressed genes in tumor with FDR<0.01. Among the selected 1,655 genes, final 212 genes were chosen according to the expression fold change and used for following analysis. The expression of up-regulated 64 genes was verified with Reverse Transcription PCR and 10 genes were identified as candidates for SCC markers. In our opinion, those candidates can be exploited as diagnostic or therapeutic purposes. Gene Ontology (GO) based analysis was performed using those 212 genes, and following categories were revealed as significant biological processes: Immune response (GO: 0006955), antigen processing (GO: 0030333), inflammatory response (GO: 0006954), Cell adhesion (GO: 0007155), and Epidermis differentiation (GO: 0008544). Gene set enrichment analysis (GSEA) also carried out on overall gene expression profile with 522 functional gene sets. Glycolysis, cell cycle, K-ras and amino acid biosynthesis related gene sets were most distinguished. These results are consistent with the known characteristics of SCC and may be interconnected to rapid cell proliferation. However, the unexpected results from ERK activation in squamous cell carcinoma gripped our attention, and further studies are under progress.