• Title/Summary/Keyword: transcriptional analysis

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Study of the Mechanism for the Growth Inhibitory Effects of Conjugated Linoleic Acid on Caco-2 Colon Cancer Cells (Conjugated Linoleic Acid에 의한 대장암 세포 증식 억제 기전 연구)

  • 김은지;오윤신;이현숙;박현서;윤정한
    • Journal of Nutrition and Health
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    • v.36 no.3
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    • pp.270-279
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    • 2003
  • Conjugated linoleic acid (CLA) is a group of positional and geometric isomers of linoleic acid (LA) and exhibits anticarcinogenic activity in a variety of animal models. We have previously observed that CLA inhibited the growth of Caco-2 cells, a human colon adenocarcinoma cell line. The present study was performed to determine whether the growth inhibitory effect of CLA is related to change in secretion of IGF- II and/or IGF-binding proteins (IGFBPs) that have been shown to regulate Caco-2 cell proliferation by an autocrine mechanism. Cells were incubated in serum-free medium with various concentrations of CLA or linoleic acid (LA). Immunoblot analysis of 24-hours, serum-free, conditioned medium using a monoclonal anti-IGF-IIantibody revealed that Caco-2 cells secreted both mature 6,500 Mr and higher Mr forms of pro IGF-II. The levels of pro IGF-II and mature IGF-IIwere decreased by 43 $\pm$ 2% and 53 $\pm$ 6%, respectively by treatment with 50 $\mu$ M CLA. LA slightly increased pro IGF- II levels. Results from Northern blot analysis showed that CLA decreased IGF-II mRNA levels at 50 $\mu$ M concentration suggesting that CLA regulation of IGF-II protein expression occurs partly at the transcriptional level. Ligand blot analysis of conditioned media using 1251-IGF-II revealed that CLA slightly decreased IGFBP-2 levels and increased IGFBP-4 levels. We confirmed our previous results that CLA inhibited cell growth in a dose-dependent manner but LA slightly increased cell growth. Exogenous IGF-II mitigated the growth inhibitory effect of CLA. These results indicate that the growth inhibitory effect of CLA may be at least in part mediated by decreasing IGF-II and IGFBP-2 secretion and increasing IGFBP-4 secretion in Caco-2 cells.

Transcriptome analysis and promoter sequence studies on early adipogenesis in 3T3-L1 cells

  • Kim, Su-Jong;Lee, Ki-Hwan;Lee, Yong-Sung;Mun, Eun-Gyeng;Kwon, Dae-Young;Cha, Youn-Soo
    • Nutrition Research and Practice
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    • v.1 no.1
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    • pp.19-28
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    • 2007
  • To identify regulatory molecules which play key roles in the development of obesity, we investigated the transcriptional profiles in 3T3-L1 cells at early stage of differentiation and analyzed the promoter sequences of differentially regulated genes. One hundred and sixty-one (161) genes were found to have significant changes in expression at the 2nd day following treatment with differentiation cocktail. Among them, 86 transcripts were up-regulated and 75 transcripts were down-regulated. The 161 transcripts were classified into 10 categories according to their functional roles; cytoskeleton, cell adhesion, immune, defense response, metabolism, protein modification, protein metabolism, regulation of transcription, signal transduction and transporter. To identify transcription factors likely involved in regulating these differentially expressed genes, we analyzed the promoter sequences of up- or - down regulated genes for the presence of transcription factor binding sites (TFBSs). Based on coincidence of regulatory sites, we have identified candidate transcription factors (TFs), which include those previously known to be involved in adipogenesis (CREB, OCT-1 and c-Myc). Among them, c-Myc was also identified by our microarray data. Our approach to take advantage of the resource of the human genome sequences and the results from our microarray experiments should be validated by further studies of promoter occupancy and TF perturbation.

Biocomputational Characterization and Evolutionary Analysis of Bubaline Dicer1 Enzyme

  • Singh, Jasdeep;Mukhopadhyay, Chandra Sekhar;Arora, Jaspreet Singh;Kaur, Simarjeet
    • Asian-Australasian Journal of Animal Sciences
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    • v.28 no.6
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    • pp.876-887
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    • 2015
  • Dicer, an ribonuclease type III type endonuclease, is the key enzyme involved in biogenesis of microRNAs (miRNAs) and small interfering RNAs (siRNAs), and thus plays a critical role in RNA interference through post transcriptional regulation of gene expression. This enzyme has not been well studied in the Indian water buffalo, an important species known for disease resistance and high milk production. In this study, the primary coding sequence (5,778 bp) of bubaline dicer (GenBank: AB969677.1) was determined and the bubaline Dicer1 biocomputationally characterized to determine the phylogenetic signature among higher eukaryotes. The evolutionary tree revealed that all the transcript variants of Dicer1 belonging to a specific species were within the same node and the sequences belonging to primates, rodents and lagomorphs, avians and reptiles formed independent clusters. The bubaline dicer1 is closely related to that of cattle and other ruminants and significantly divergent from dicer of lower species such as tapeworm, sea urchin and fruit fly. Evolutionary divergence analysis conducted using MEGA6 software indicated that dicer has undergone purifying selection over the time. Seventeen divergent sequences, representing each of the families/taxa were selected to study the specific regions of positive vis-$\grave{a}$-vis negative selection using different models like single likelihood ancestor counting, fixed effects likelihood, and random effects likelihood of Datamonkey server. Comparative analysis of the domain structure revealed that Dicer1 is conserved across mammalian species while variation both in terms of length of Dicer enzyme and presence or absence of domain is evident in the lower organisms.

The Arabidopsis beta-carotene hydroxylase gene promoter for a strong constitutive expression of transgene

  • Liang, Ying Shi;Bae, Hee-Jin;Kang, Sang-Ho;Lee, Theresa;Kim, Min Gab;Kim, Young-Mi;Ha, Sun-Hwa
    • Plant Biotechnology Reports
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    • v.3 no.4
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    • pp.325-331
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    • 2009
  • To efficiently express a gene of interest in transgenic plants, the choice of promoter is a crucial factor as it directly affects the expression of the transgene that will yield the desired phenotype. The Arabidopsis ${\beta}-carotene$ hydroxylase 1 gene (AtBch1) shows constitutive and ubiquitous expression and was thus selected as one of best candidates for constitutive promoter analysis by both in silico northern blotting and semi-quantitative RT-PCR analysis. To investigate AtBch1 promoter activity, the 1,981-bp 5'-upstream region of this gene was fused with ${\beta}-glucuronidase$ (GUS) and transformed into Arabidopsis. Through the molecular characterization of transgenic leaf tissues, the AtBch1 promoter generated strong activity that drives 1.8- and 2-fold higher GUS expression than the cauliflower mosaic virus 35S (35S) promoter at the transcriptional and translational levels, respectively. Furthermore, the GUS enzyme activity driven by the AtBch1 promoter was 2.8-fold higher than that produced by the 35S promoter. By histochemical GUS staining, the ubiquitous expression of the AtBch1 promoter was observed in all tissues of Arabidopsis. Semi-quantitative RT-PCR analysis with different tissues further showed that this promoter serves as a strong constitutive driver of transgene expression in dicot plants.

Different Responses in Brain Regions upon Heat Shock in Adult Zebrafish (Danio rerio)

  • Hwang, Chang-Nam;Lee, Dong-Ho;Lee, Sang-Ho
    • Development and Reproduction
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    • v.13 no.3
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    • pp.199-205
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    • 2009
  • HSP70 has widely been induced in in vivo hyperthermia conditions in various organisms to study gene regulation and recently neuroprotectve roles of the induced gene expression under varying conditions. We investigated different responses among various tissues in zebrafish under heat shock to evaluate whether spatial and temporal expression pattern of zebrafish (z) hsp70 in transcriptional and translational level under heat shock stress in different brain regions. Heat shock groups were given for 1 h at $37^{\circ}C$ after recovery by transferring the treated animals back to $28^{\circ}C$ for 1, 2 and 24 h for recovery, respectively. Control (CTRL) group was kept at $28^{\circ}C$. At the end of treatments, five animals were collected and used for isolation of total RNAs and peptides from the corresponding tissues. Expression of zhsp70 mRNA showed different patterns in recovery periods in the tissues including the brain, eye, intestines, muscles, heart and testis by RT-PCR. Unlike the RT-PCR analysis, Northern blot analysis demonstrated nearly 30-fold increase in zhsp70 at 1 h heat shock, suggesting that RT-PCR may not be appropriate in unmasking regulation of the time-dependent zhsp70 expression. In the experiment involving different brain regions, the cerebellum showed gradual activation at 1 h to R1h and decreases in R2h and R24h, while the medulla oblongata and optic tectum showed gradual increase at R1h and decrease at R24h, indicating that different brain tissues respond specifically to heat shock in inducing zhsp70 and recovering from the heat shock status. Western blot analysis also demonstrated that the intracellular levels of zHSP70 in three different brain regions including the cerebellum, medulla oblongata and optic tectum are differently induced and recovered to normal state. These results clearly demonstrate that different regions of the body and the brain tissues are responding differently to heat shock in the aspects of its level of expression and speed of recovery.

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Cloning and Expression Analysis of a Chitinase Gene Crchi1 from the Mycoparasitic Fungus Clonostachys rosea (syn. Gliocladium roseum)

  • Gan, Zhongwei;Yang, Jinkui;Tao, Nan;Yu, Zefen;Zhang, Ke-Qin
    • Journal of Microbiology
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    • v.45 no.5
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    • pp.422-430
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    • 2007
  • Clonostachys rosea (syn. Gliocladium roseum) is a well-known biocontrol agent and widely distributed around the world. In this study, an endochitinase gene Crchi1 was isolated from the mycoparasitic fungus C. rosea using the DNA walking strategy. The Crchi1 ORF is 1,746 bp long and interrupted by three introns. The cloned gene Crchi1 encodes 426 amino acid residues and shares a high degree of similarity with other chitinases from entomopathogenic and mycoparasitic fungi. Several putative binding sites for transcriptional regulation of Crchi1 in response to carbon (5'-SYGGRG-3') and nitrogen (5'-GATA-3') were identified in the upstream of Crchi1. Expression of Crchi1 gene in different carbon sources was analyzed using real-time PCR (RT-PCR). We found that the Crchi1 expression was suppressed by glucose but strongly stimulated by chitin or solubilized components of the cell wall from Rhizoctonia solani. Phylogenetic analysis of chitinases from entomopathogenic and mycoparasitic fungi suggests that these chitinases have probably evolved from a common ancestor.

MicroRNA Analysis in Normal Human Oral Keratinocytes and YD-38 Human Oral Cancer Cells

  • Kim, Hye-Ryun;Park, Eu-Teum;Cho, Kwang-Hee;Kim, Do-Kyung
    • International Journal of Oral Biology
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    • v.36 no.4
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    • pp.179-185
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    • 2011
  • MicroRNAs (miRNAs) are small non-coding RNAs that mediate gene expression at the post-transcriptional level by degrading or repressing targeted mRNAs. These molecules are about 21-25 nucleotides in length and exert their effects by binding to partially complementary sites in mRNAs, predominantly in the 3'-untranslated region (3'-UTR). Recent evidence has demonstrated that miRNAs can function as oncogenes or tumor suppressors through the modulation of multiple oncogenic cellular processes in cancer development, including initiation, cell proliferation, apoptosis, invasion and metastasis. In our present study, we examined the expression profile of miRNAs related to oral cancer cell growth inhibition using normal human oral keratinocytes (NHOK) and YD-38 human oral cancer cells. By miRNA microassay analysis, 40 and 31 miRNAs among the 1,769 examined were found to be up- and down-regulated in YD-38 cells compared with NHOK cells, respectively. Using qRT-PCR analysis, the expression levels of miR-30a and miR-1246 were found to be increased in YD-38 cells compared with NHOK cells, whereas miR-203 and miR-125a were observed to be decreased. Importantly, the overexpression of miR-203 and miR-125a significantly inhibited the growth of YD-38 cells. This finding and the microarray data indicate the involvement of specific miRNAs in the development and progression of oral cancer.

Analysis of gene expression profiles to study malaria vaccine dose efficacy and immune response modulation

  • Dey, Supantha;Kaur, Harpreet;Mazumder, Mohit;Brodsky, Elia
    • Genomics & Informatics
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    • v.20 no.3
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    • pp.32.1-32.15
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    • 2022
  • Malaria is a life-threatening disease, and Africa is still one of the most affected endemic regions despite years of policy to limit infection and transmission rates. Further, studies into the variable efficacy of the vaccine are needed to provide a better understanding of protective immunity. Thus, the current study is designed to delineate the effect of each dose of vaccine on the transcriptional profiles of subjects to determine its efficacy and understand the molecular mechanisms underlying the protection this vaccine provides. Here, we used gene expression profiles of pre and post-vaccination patients after various doses of RTS,S based on samples collected from the Gene Expression Omnibus datasets. Subsequently, differential gene expression analysis using edgeR revealed the significantly (false discovery rate < 0.005) 158 downregulated and 61 upregulated genes between control vs. controlled human malaria infection samples. Further, enrichment analysis of significant genes delineated the involvement of CCL8, CXCL10, CXCL11, XCR1, CSF3, IFNB1, IFNE, IL12B, IL22, IL6, IL27, etc., genes which found to be upregulated after earlier doses but downregulated after the 3rd dose in cytokine-chemokine pathways. Notably, we identified 13 cytokine genes whose expression significantly varied during three doses. Eventually, these findings give insight into the dual role of cytokine responses in malaria pathogenesis. The variations in their expression patterns after various doses of vaccination are linked to the protection as it decreases the severe inflammatory effects in malaria patients. This study will be helpful in designing a better vaccine against malaria and understanding the functions of cytokine response as well.

FCAnalyzer: A Functional Clustering Analysis Tool for Predicted Transcription Regulatory Elements and Gene Ontology Terms

  • Kim, Sang-Bae;Ryu, Gil-Mi;Kim, Young-Jin;Heo, Jee-Yeon;Park, Chan;Oh, Berm-Seok;Kim, Hyung-Lae;Kimm, Ku-Chan;Kim, Kyu-Won;Kim, Young-Youl
    • Genomics & Informatics
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    • v.5 no.1
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    • pp.10-18
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    • 2007
  • Numerous studies have reported that genes with similar expression patterns are co-regulated. From gene expression data, we have assumed that genes having similar expression pattern would share similar transcription factor binding sites (TFBSs). These function as the binding regions for transcription factors (TFs) and thereby regulate gene expression. In this context, various analysis tools have been developed. However, they have shortcomings in the combined analysis of expression patterns and significant TFBSs and in the functional analysis of target genes of significantly overrepresented putative regulators. In this study, we present a web-based A Functional Clustering Analysis Tool for Predicted Transcription Regulatory Elements and Gene Ontology Terms (FCAnalyzer). This system integrates microarray clustering data with similar expression patterns, and TFBS data in each cluster. FCAnalyzer is designed to perform two independent clustering procedures. The first process clusters gene expression profiles using the K-means clustering method, and the second process clusters predicted TFBSs in the upstream region of previously clustered genes using the hierarchical biclustering method for simultaneous grouping of genes and samples. This system offers retrieved information for predicted TFBSs in each cluster using $Match^{TM}$ in the TRANSFAC database. We used gene ontology term analysis for functional annotation of genes in the same cluster. We also provide the user with a combinatorial TFBS analysis of TFBS pairs. The enrichment of TFBS analysis and GO term analysis is statistically by the calculation of P values based on Fisher’s exact test, hypergeometric distribution and Bonferroni correction. FCAnalyzer is a web-based, user-friendly functional clustering analysis system that facilitates the transcriptional regulatory analysis of co-expressed genes. This system presents the analyses of clustered genes, significant TFBSs, significantly enriched TFBS combinations, their target genes and TFBS-TF pairs.

Molecular Cloning and Sequencing of the Ecdysteroid UDP-Glucosyl-transferase Gene, EGT, from Bombyx mori Nuclear Polyhedrosis Virus K1

  • Park, Hye-Jin;Chung, Eun-Hwa;Lee, Kwang-Sik;Han, Ji-Hee;Lee, Seong-Jin;Sohn, Hung-Dae;Jin, Byung-Rae
    • International Journal of Industrial Entomology and Biomaterials
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    • v.3 no.1
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    • pp.37-41
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    • 2001
  • The ecdysteroid UDP-glucosyltransferase (egt) gene isolated from Bombyx mori nuclear polyhedrosis virus (BmNPV) K1 strain was compared to its homologue from Autographa californica NPV (AcNPV) and Bm NPV T3. The egt gene of BmNPV-K1 encoded 506 amino acid open reading frame, and was 99.6% identical at the amino acid level and 99.2% identical at the nucleotide level to BmNPV T3. The BmNPV-K1 egt gene showed highly identity to AcNPV and BmNPV T3 strain. The BmNPV-K1 egt gene was different from amino acid sequence at 2 positions, 19 and 72, in BmNPV T3. The genomic location of egt gene in the BmNPV-K1 was confirmed by Southern blot analysis and its expression patterns at the transcriptional level in the infected cells were confirmed by Northern hybridization analysis. Transcripts of the egt of Bm NPV-K1 peaked around 12 hrs postinfection (p.i.) and reduced at 24 hrs p.i.

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