• Toxicological Research
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• v.27 no.1
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• pp.43-48
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• 2011

Even though exposure to benzene has been linked to a variety of cancers including leukemia, the detailed molecular mechanisms relevant to benzene-induced carcinogenesis remain to be clearly elucidated. In this study, we evaluated the effects of benzene on differential gene expression in a leukemia cell line. The K562 leukemia cell line used in this study was cultured for 3 h with 10 mM benzene and RNA was extracted. To analyze the gene expression profiles, a 41,000 human whole genome chip was employed for cDNA microarray analysis. We initially identified 6,562 genes whose expression was altered by benzene treatment. Among these, 3,395 genes were upregulated and 3,167 genes were downregulated by more than 2-fold, respectively. The results of functional classification showed that the identified genes were involved in biological pathways including transcription, cell proliferation, the cell cycle, and apoptosis. These gene expression profiles should provide us with further insights into the molecular mechanisms underlying benzene-induced carcinogenesis, including leukemia.

• Molecular & Cellular Toxicology
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• v.3 no.2
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• pp.98-106
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• 2007

Genotoxic stress triggers a variety of biological responses including the transcriptional activation of genes regulating DNA repair, cell survival and cell death. In this study, we investigated to examine gene expression profiles and genotoxic response in TK6 cells treated with DNA damaging agents MNNG (N-methyl-N'-nitrosoguanidine) and hydrogen peroxide $(H_2O_2)$. We extracted total RNA in three independent experiments and hybridized cRNA probes with oligo DNA chip (Applied Biosystems Human Genome Survey Microarray). We analyzed raw signal data with R program and AVADIS software and identified a number of deregulated genes with more than 1.5 log-scale fold change and statistical significancy. We indentified 14 genes including G protein alpha 12 showing deregulation by MNNG. The deregulated genes by MNNG represent the biological pathway regarding MAP kinase signaling pathway. Hydrogen peroxide altered 188 genes including sulfiredoxins. These results show that MNNG and $H_2O_2$ have both uniquely regulated genes that provide the potential to serve as biomarkers of exposure to DNA damaging agents.

• Journal of Life Science
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• v.19 no.8
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• pp.1159-1163
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• 2009

It has been postulated that endoplasmic (ER) stress is involved in the development of several diseases. However, the detailed molecular mechanisms have not been fully understood. Therefore, we characterized a genetic network of genes induced by ER stress using cDNA microarray and gene set expression coherence analysis (GSECA), and identified gene function as well as several transcription regulators associated with ER stress. We analyzed time-dependent gene expression profiles in thapsigargin-treated Sk-Hep1 using an oligonucleotide expression chip, and then selected functional gene sets with significantly high expression coherence which was processed into functional clusters according to the expression similarities. The functions related to sugar binding, lysosome, ribosomal protein, ER lumen, and ER to golgi transport increased, whereas the functions with mRNA processing, DNA replication, DNA repair, cell cycle, electron transport chain and helicase activity decreased. Furthermore, functional clusters were investigated for the enrichment of regulatory motifs using GSECA, and several transcriptional regulators associated with regulation of ER-induced gene expression were found.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.8
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• pp.4553-4557
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• 2013

Objective: The purpose of this study was to identify genes related to bladder cancer with samples from normal and disease cases by microarray chip. Methods: After downloading the gene expression profile GSE3167 from Gene Expression Omnibus database which includes 50 bladder samples, comprising 9 normal and 41 disease samples, differentially expressed genes were identified with packages in R language. The selected differentially expressed genes were further analyzed using bioinformatics methods. Firstly, molecular functions, biological processes and cell component analysis were researched by software Gestalt. Then, software String was used to search interaction relationships among differentially expressed genes, and hub genes of the network were selected. Finally, by using plugins of software Cytoscape, Mcode and Bingo, module analysis of hub-genes was performed. Results: A total of 221 genes were identified as differentially expressed by comparing normal and disease bladder samples, and a network as well as the hub gene C1QBP was obtained from the network. The C1QBP module had the closest relationship to production of molecular mediators involved in inflammatory responses. Conclusion: We obtained differentially expressed genes of bladder cancer by microarray, and both PRDX2 and YWHAZ in the module with hub gene C1QBP were most significantly related to production of molecular mediators involved in inflammatory responses. From knowledge of inflammatory responses and cancer, our results showed that, the hub gene and its module could induce inflammation in bladder cancer. These related genes are candidate bio-markers for bladder cancer diagnosis and might be helpful in designing novel therapies.

• The Korean Journal of Physiology and Pharmacology
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• v.10 no.5
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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.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.4
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• pp.853-860
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• 2006

This study was performed to investigate genes which are differently expressed in human blood by administrating of OLT-2. OLT-2 was medical precipitation composed of three medicinal herbs, Ginseng Radix, Astragali Radix, Glycyrrhizae Radix, and anti-leukemia effect of it was evaluated from Byung Hun Jeon of Wonkwang University this study was approved by Institutional Review Board of Korea Institute of Oriental Medicine (Taejeon, Korea) and four male subjects participated in this study. Gene expressions were evaluated by cDNA chip, in which 24,000 genes were spotted. Hierarchical cluster and biological process against the genes, which expression changes were more than 1.6 fold, were constructed by cluster 3.0 providing Stanford University and EASE(http://apps1 .maid.nih.gov/DAVID). Five groups were clustered according to their expression patterns. Group A contained gene decreased by OLT-2 and increased genes by OLT-2 were involved in Group B, C, D. In biological process, expression of genes involved in cytokine or cell calcium signaling, such as interleukin 18 and G-protein beta 4 were increased, but protein tyrosine phosphatase receptor type c, which function is cell adhesion between antigen-presenting cell and T or B-cell, was decreased by OLT-2. This study provides the most comprehensive available survey of gene expression changes in response to anti-leukemia effect of OLT-2 in human blood.

• Journal of Life Science
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• v.22 no.3
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• pp.366-372
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• 2012

This study was conducted to estimate the extent of linkage disequilibrium (LD) and effective population size using whole genomic single nucleotide polymorphisms (SNP) genotyped by DNA chip in Hanwoo. Using the blood samples of 35 young bulls born from 2005 to 2008 and their progenies (N=253) in a Hanwoo nucleus population collected from Hanwoo Improvement Center, 51,582 SNPs were genotyped using Bovine SNP50 chips. A total of 40,851 SNPs were used in this study after elimination of SNPs with a missing genotyping rate of over 10 percent and monomorphic SNPs (10,730 SNPs). The total autosomal genome length, measured as the sum of the longest syntenic pairs of SNPs by chromosome, was 2,541.6 Mb (Mega base pairs). The average distances of all adjacent pairs by each BTA ranged from 0.55 to 0.74 cM. Decay of LD showed an exponential trend with physical distance. The means of LD ($r^2$) among syntenic SNP pairs were 0.136 at a range of 0-0.1 Mb in physical distance and 0.06 at a range of 0.1-0.2 Mb. When these results were used for Luo's formula, about 2,000 phenotypic records were found to be required to achieve power > 0.9 to detect 5% QTL in the population of Hanwoo. As a result of estimating effective population size by generation in Hanwoo, the estimated effective population size for the current status was 84 heads and the estimate of effective population size for 50 generations of ancestors was 1,150 heads. The average decreasing rates of effective population size by generation were 9.0% at about five generations and 17.3% at the current generation. The main cause of the rapid decrease in effective population size was considered to be the intensive use of a few prominent sires since the application of artificial insemination technology in Korea. To increase and/or sustain the effective population size, the selection of various proven bulls and mating systems that consider genetic diversity are needed.

• Mycobiology
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• v.38 no.2
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• pp.144-148
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• 2010

$\beta$-Glucans have been known to exhibit antitumor activities by potentiating host immunity by an unknown mechanism. The C-type lectin dectin-1, a $\beta$-glucan receptor, is found on the macrophage and can recognize various $\beta$-glucans. Previously, we demonstrated the presence of $\beta$-glucan receptor, dectin-1, on the Raw 264.7 cells as well as on murine mucosal organs, such as the thymus, the lung, and the spleen. In order to investigate immunopotentiation of innate immunity by $\beta$-glucan, we stimulated a murine macrophage Raw 264.7 cell line with $\beta$-glucans from Pleurotus ostreatus, Saccharomyces cerevisiae, and Laminaria digitata. Then, we analyzed cytokines such as tumor necrosis factor (TNF)-$\alpha$ and interleukin (IL)-6 by reverse transcription-polymerase chain reaction (RT-PCR). In addition we analyzed gene expression patterns in $\beta$-glucan-treated Raw 264.7 cells by applying total mRNA to cDNA microarray to investigate the expression of 7,000 known genes. When stimulated with $\beta$-glucans, the macrophage cells increased TNF-$\alpha$ expression. When co-stimulation of the cells with $\beta$-glucan and lipopolysaccharide (LPS), a synergy effect was observed by increased TNF-$\alpha$ expression. In IL-6 expression, any of the $\beta$-glucans tested could not induce IL-6 expression by itself. However, when co-stimulation occurred with $\beta$-glucan and LPS, the cells showed strong synergistic effects by increased IL-6 expression. Chip analysis showed that $\beta$-glucan of P. ostreatus increased gene expressions of immunomodulating gene families such as kinases, lectin associated genes and TNF-related genes in the macrophage cell line. Induction of TNF receptor expression by FACS analysis was synergized only when co-stimulated with $\beta$-glucan and LPS, not with $\beta$-glucan alone. From these data, $\beta$-glucan increased expressions of immunomodulating genes and showed synergistic effect with LPS.

• Journal of Animal Science and Technology
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• v.50 no.4
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• pp.475-484
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• 2008

The current study was undertaken to determine the effect of retinoic acid(RA) on differentiation and gene expression of pig preadipocytes. The preadipocytes were isolated from the backfat of the new-born pigs. RA was treated to the cultured cells for 4 days and RNA was extracted from the cells. Isolated RNA went through in situ hybridization using the 14,688-gene cDNA microarray chip. Degree of cell differentiation was determined by measuring glycerol 3-phosphate dehydrogenase activity. RA decreased differentiation of pig preadipocytes by 78%. Fourteen genes were significantly up-regulated by RA, including genes known to be involved in lipid metabolism, particulary sphingomyelin phosphodiesterase, apolipoprotein R precursor, growth factor receptor-bound protein 14, retinoic acid receptor RXR gamma. However, the expression of vascular endothelial growth factor D precursor and growth hormone receptor precursor genes playing a central role in cell growth, was greatly decreased. These results suggest that RA inhibits differentiation of pig preadiocytes by regulation of gene expression of the growth factor or growth hormone receptor.

• Journal of Life Science
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• v.20 no.4
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• pp.584-588
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• 2010

Clusterin is an 80 kDa heterodimetric glycosylated protein which plays diverse biological roles in various tissues and organs. Clusterin is reported to be associated with the pathogenesis of coronary artery disease and atherosclerosis. Therefore, we investigated the genotype for the T