• Biomolecules & Therapeutics
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• v.28 no.1
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• pp.1-17
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• 2020

Myeloid-derived suppressor cells (MDSCs) are immature myeloid cells that exert suppressive function on the immune response. MDSCs expand in tumor-bearing hosts or in the tumor microenvironment and suppress T cell responses via various mechanisms, whereas a reduction in their activities has been observed in autoimmune diseases or infections. It has been reported that the symptoms of various diseases, including malignant tumors, can be alleviated by targeting MDSCs. Moreover, MDSCs can contribute to patient resistance to therapy using immune checkpoint inhibitors. In line with these therapeutic approaches, diverse oligonucleotide-based molecules and small molecules have been evaluated for their therapeutic efficacy in several disease models via the modulation of MDSC activity. In the current review, MDSC-targeting oligonucleotides and small molecules are briefly summarized, and we highlight the immunomodulatory effects on MDSCs in a variety of disease models and the application of MDSC-targeting molecules for immuno-oncologic therapy.

• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.6
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• pp.505-509
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• 2005

For the purpose of developing a direct label-free electrochemical detection system, we have systematically investigated the electrochemical signatures of each step in the preparation procedure, from a bare gold electrode to the hybridization of label-free complementary DNA, for the streptavidin-modified electrode. For the purpose of this investigation, we obtained the following pertinent data; cyclic voltammogram measurements, electrochemical impedance spectra and square wave voltammogram measurements, in $Fe(CN)_6^{3-}/Fe(CN)_6^{4-}$ solution (which was utilized as the electron transfer redox mediator). The oligonucleotide molecules on the streptavidin-modified electrodes exhibited intrinsic redox activity in the ferrocyanide-mediated electrochemical measurements. Furthermore, the investigation of electrochemical electron transfer, according to the sequence of oligonucleotide molecules, was also undertaken. This work demonstrates that direct label-free oligonucleotide electrical recognition, based on biofunctional streptavidin-modified gold electrodes, could lead to the development of a new biosensor protocol for the expansion of rapid, cost-effective detection systems.

• BMB Reports
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• v.48 no.4
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• pp.234-237
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• 2015

Aptamers, composed of single-stranded DNA or RNA oligonucleotides that interact with target molecules through a specific three-dimensional structure, are selected from pools of combinatorial oligonucleotide libraries. With their high specificity and affinity for target proteins, ease of synthesis and modification, and low immunogenicity and toxicity, aptamers are considered to be attractive molecules for development as anticancer therapeutics. Two aptamers - one targeting nucleolin and a second targeting CXCL12 - are currently undergoing clinical trials for treating cancer patients, and many more are under study. In this mini-review, we present the current clinical status of aptamers and aptamer-based cancer therapeutics. We also discuss advantages, limitations, and prospects for aptamers as cancer therapeutics. [BMB Reports 2015; 48(4): 234-237]

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.48 no.3
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• pp.53-59
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• 2011

Charge transfer through DNA oligonucleotides has been investigated for potential applications of DNA into molecular electrooptic switching devices. Electrons were injected using gold electrode probes where DNA oligomers were adsorbed that are separated in medium. The results show that increased adsorption of DNA reduces the ionization current due to the combined effect of charge transfer through DNA and surface-limited charge transport. The probe-based charge injection was extended to examine the capability of extinguishing fluorescence of Cy3 dye molecules attached to DNA. It is expected that the results may be employed to implementing a novel electrooptic switching device based on DNA molecules.

• Biotechnology and Bioprocess Engineering:BBE
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• v.8 no.4
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• pp.221-226
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• 2003

With the current rapid development of nanotechnology and synthesis technology for designed oligonucleotides or oligonucleotide-modified nanoparticle conjugates, the combined strategies have become one of the most valuable methods in detection technology for DNA analysis. Using the uniquely recognizable interactions of pre-designed DNA molecules in assembling nanoparticles, various novel approaches have been recently developed towards detecting specific DNA sequences. Here we describe the key fundamentals and issues of this promising strategies ranging from the initial findings of rationally designed DNA-based assembly of nanoparticles to the extended chip-based detection system. Some limitations of these new strategies and possible approaches will be also discussed for the practical application in the area of DNA microarray detection.

• Tuberculosis and Respiratory Diseases
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• v.48 no.5
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• pp.699-708
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• 2000

Background : A presumptive histopathologic diagnosis of tuberculosis is commonly based on the finding of acid-fast bacilli upon microscopic examination of a diagnostic specimens. Although this traditional histochemical staining method is satisfactory, it is time-consuming and not species-specific. For more specific assessment, in situ hybridization assay with oligonucleotide probes is introduced. Methods : The human surgical specimens were obtained from tuberculosis patients, and experimental specimens were made by injecting cultured M. tuberculosis organisms into fresh rat liver. Oligonucleotide probes complementary to ribosomal RNA portion were synthesized and labeled with multiple biotin molecules. For a rapid detection, all procedures were carried out using manual capillary action technology on the Microprobe staining system. Results : The in situ hybridization assay produced a positive reaction in experimental specimens (80-90% sensitivity) after pepsin-HCl pre-treatment for a good permeabilization of probes, but reliable result was not obtained from human surgical specimens. Conclusion : It is, therefore, suggested that biotin-labeled oligonucleotide probes have considerable potential for identification and in situ detection of M. tuberculosis but, there are some barriers to overcome for the diagnostic use of this method.

• Journal of Applied Biological Chemistry
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• v.42 no.3
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• pp.119-124
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• 1999

About two thirds of the naturally occurring antibiotics have been discovered from actinomycetes. Therefore, the probability of discovering further new antibiotics from actinomycetes is declining as many known metabolites are isolated repeatedly. However, various efforts leave been made in order to enhance the probability of discovering novel compounds. In the present study, we have developed new screening strategies based on the antibiotic biosynthetic pathway, and the genetic information, utilizing polymerase chain reaction. We have selected macrolide type polyketides. In order to divide the ansamycin group antibotic of macrolide type polyketides, we have selected 3-amino-5-hydroxybenzoic acid (AHBA) moiety which contains a biosynthetically unique structural element in the group as a target molecules. Oligonucleotide primers were designed to amplify DNA fragments of macrolide type polyketide synthase and AHBA synthase genes from fourteen actinomycetes species. This method was successfully applied to all three of the known macrolide type polyketide produccing actinomycetes tested. In addition, it also identified the presence of potential macrolide type polyketide producing genes from seven actinomycetes that were known to produce none of macrolide type polyketides, and AHBA biosynthetic genes in one actinomycetes. This technique is potentially useful for the screening of new antibiotices and cloning of their biosynthetic genes.

• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.88-92
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• 2005

Aptamer is the single-stranded oligonucleotide which binds to various target molecules such as proteins, peptides, lipids and small organic molecules with high affinity and specificity. DNA aptamers specific for the $17{\beta}-estradiol$ were selected by SELEX (Systematic Evolution of Ligands by EXponential enrichment) process from a random DNA library. These DNA aptamers have a high affinity to $17{\beta}-estradiol$ as an endocrine disrupting chemical. Nanowell and $200{\mu}m$ gold electrode were used as substrate for DNA aptamer immobilization and electrochemical analysis. Especially, nanowell gold electrode was fabricated by e-beam lithography. The size of single nanowell is 130nm and 40,000 nanowells were deposited on one gold electrode. The immobilization method was based on the interaction between the biotinylated aptamer and streptavidin deposited on gold electrode previously. Immobilization procedure was optimized by surface plasma resonance (SPR) and electrochemical analysis. After the immobilization of DNA aptamer on streptavidin modified gold electrode, $17{\beta}-estradiol$ solution was treated on aptamer immobilized gold electrode. The current of gold electrode was decreased by the binding of $17{\beta}-estradiol$ to DNA aptamer immobilized on gold electrode. However, in negative control experiments of 1-aminoanthraquinone and 2-methoxynaphthalene, the current was rarely decreased. And more sensitive data was obtained from nanowell gold electrode comparing with $200{\mu}m$ gold electrode.

• Molecular & Cellular Toxicology
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• v.5 no.1
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• pp.44-50
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• 2009

This study was conducted to evaluate the inflammation mechanisms of tumor necrosis factor-$\alpha$ (TNF-$\alpha$), interleukin-4 (IL-4), and IL-$1{\beta}$-induced stimulation of A549 human epithelial cells. In the present study, A549 cells were stimulated with TNF-$\alpha$, IL-4 and IL-$1{\beta}$ to induce expression of chemokines and adhesion molecules involved in eosinophil chemotaxis. The effects of TNF-$\alpha$, IL-4 and IL-$1{\beta}$ on gene expression profiles in A549 cells were evaluated by oligonucleotide microarray and Real time RT-PCR. The gene expression profiles for the A549 cells varied depending on the cytokines. Also, the results of the microarray and Real time RT-PCR revealed that inflammatory-related genes were up-regulated in cytokine stimulated A549 cells. Cytokines can affect inflammation in A549 cells. A microarray-based genomic survey is a high-throughput approach that enables evaluation of gene expression in cytokine stimulated cell lines.

• Molecules and Cells
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• v.38 no.6
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• pp.580-586
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• 2015

While increasing evidence indicates the important function of histone methylation during development, how this process influences cardiac development in vertebrates has not been explored. Here, we elucidate the functions of two histone H3 lysine 4 (H3K4) methylation enzymes, SMYD3 and SETD7, during zebrafish heart morphogenesis using gene expression profiling by whole mount in situ hybridization and antisense morpholino oligonucleotide (MO)-based gene knockdown. We find both smyd3 and setd7 are highly expressed within developing zebrafish heart and knock-down of these genes led to severe defects in cardiac morphogenesis without altering the expressions pattern of heart markers, including cmlc2, vmhc, and amhc. Furthermore, double knock-down by coinjection of smyd3 and setd7 MOs caused the synergistic defects in heart development. As similar to knock-down effect, overexpression of these genes also caused the heart morphogenesis defect in zebrafish. These results indicate that histone modifying enzymes, SMYD3 and SETD7, appear to function synergistically during heart development and their proper functioning is essential for normal heart morphogenesis during development.