Woong Jung
Kyung Hee University
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Publication
Featured researches published by Woong Jung.
Analytical Chemistry | 2016
Chaesun Hong; Ahruem Baek; Sang Soo Hah; Woong Jung; Dong-Eun Kim
We have developed a facile fluorometric system for the detection of microRNA (miRNA), using rolling circle amplification (RCA), graphene oxide (GO), and fluorescently labeled peptide nucleic acid (F-PNA). The padlock probe DNA complementary to a target miRNA was selectively ligated to form circular DNA that was then used as the template for RCA. F-PNAs complementary to the target miRNA were annealed to multiple sites of the isothermally amplified single-stranded RCA product (RCAP) containing multiple target miRNA sequences. This F-PNA/RCAP duplex is less adsorbed onto the GO monolayer, thus attenuating the quenching of F-PNA fluorescence by GO. In the absence of target miRNA (and hence the absence of RCA and duplex formation), the free F-PNA is completely adsorbed onto the GO monolayer and fluorescence quenching ensues. Thus, GO-based fluorescence detection coupled with isothermal gene amplification would be a simple and convenient method for the quantitative detection of miRNA.
Journal of Critical Care | 2017
Hyun Kyung Park; Won Young Kim; Myung Chun Kim; Woong Jung; Byuk Sung Ko
Purpose: It is unclear whether quick sequential (sepsis‐related) organ failure assessment (qSOFA) also has prognostic value for organ failure in patients with a suspected infection. The aim of this study was to determine whether qSOFA has prognostic value when compared to systemic inflammatory response syndrome (SIRS) in predicting organ failure in patients with a suspected infection in an emergency department (ED). Methods: A retrospective observational study was conducted in an ED during a 9‐year period. We analyzed the ability of qSOFA compared to SIRS to predict the development of organ failure in patients (defined as an increase in the SOFA score of 2 points or more) using the area under receiver operating characteristic (AUROC) curve. Results: A total of 1009 patients with suspected infection were finally included in the study. The predictive validity of qSOFA for organ failure was higher than that of SIRS (AUROC = 0.814 vs. AUROC = 0.662, p = 0.02). qSOFA was also superior to SIRS in predicting in‐hospital mortality (AUROC = 0.733 vs. AUROC = 0.599, p = 0.04). When the qSOFA score was equal to or > 1, its sensitivity and specificity to predict organ failure was 75% and 82%, respectively. Conclusions: qSOFA has a superior ability compared to SIRS in predicting the occurrence of organ failure in patients with a suspected infection. However, given the low sensitivity of qSOFA, further confirmatory tests for organ failure are needed. HighlightsqSOFA at ED was superior than SIRS in predicting occurrence of organ failure in patients with suspected infection.qSOFA also has better prognostic validity at predicting in‐hospital mortality than SIRS.The cutoff value of qSOFA equal to or more than 1 point is recommended to predict organ failure.However, confirmatory tests for organ failure are needed in terms of low sensitivity and NPV of qSOFA.
Analytical Biochemistry | 2013
Hyunjung Seo; Sohyun Kim; Jae Il Kim; Hyunook Kang; Woong Jung; Woon-Seok Yeo
We report on a simple, fast, and highly sensitive method that allows femtomolar detection of microRNAs (miRNAs) without the need of polymerase chain reaction using a nanoengineered micro gold shell (μAuS) and laser desorption/ionization time-of-flight (LDI-TOF) mass spectrometry (MS). Target miRNAs are selectively captured by a chemically decorated gold chip and a μAuS, which carries with it a large number of small molecules, termed amplification tags (Am-tags). Subsequent LDI-TOF MS analysis allows a highly amplified mass signal of Am-tags for the presence of target miRNAs in a sample, resulting in ultrasensitive detection.
Bioorganic & Medicinal Chemistry Letters | 2012
Seonmi Shin; Hye Yeon Nam; Eun Jeong Lee; Woong Jung; Sang Soo Hah
Mucin 1 (Muc1) is a glycoprotein expressed on most epithelial cell surfaces, which has been confirmed as a useful biomarker for the diagnosis of early cancers. In this study, we demonstrate that a quantum dot (QD)-aptamer beacon acts by folding-induced dissociation of a DNA intercalating dye, BOBO-3, in the presence of the target molecules, Muc1. Release of intercalated BOBO-3s from the QD-conjugated aptamers results in a decrease in QD fluorescence resonance energy transfer (FRET)-mediated BOBO-3 emission, allowing for label-free Muc1 detection and quantitation. We attain highly specific and wide-range detection (from 50nM to 20μM) of Muc1, suggesting that our QD-aptamer beacon can be a potential alternative to immuno-based assays for Muc1 detection. The detection methodology is expected to be improved for the early diagnosis of different types of epithelial cancers of large populations.
Biosensors and Bioelectronics | 2013
Jisu Kim; Gwan-Ho Lee; Woong Jung; Sang Soo Hah
Aptamer-based biochips for selective cell detection and quantitation in combination of the recent biochip technology and the conventional cell staining methods are described. Using a model system comprising HER2- or PSMA-positive cells as the analytes and single-stranded RNA aptamers specific for HER2 or PSMA as immobilized ligands on chips, we could demonstrate that aptamers were equivalent or superior to antibodies in terms of specificity and sensitivity, respectively. In particular, our PSMA-specific sensor was found to have the characteristics of good stability, reproducibility and reusability, with detection limit as low as 10(3) LNCaP cells. In conclusion, we could show the suitability of nucleic acid aptamers as low molecular weight receptors on biochips for sensitive and specific cell detection and quantitation for future diagnostics development.
Analytical Biochemistry | 2011
Kkothanahreum Park; Bo-Ra Choi; Yea Seul Kim; Seonmi Shin; Sang Soo Hah; Woong Jung; Sangtaek Oh; Dong-Eun Kim
A single nucleotide polymorphism (SNP) is a common genetic variation when a single nucleotide differs between members of a species or paired chromosome. Due to its association with disease susceptibility and drug resistance, SNP detection is of great value in studying the variation in drug responses. Here we present two quantitative SNP detection methods for a single-base mismatch in RNA, based on nick-joining and nick-generating activities of T4 RNA ligase and DNAzyme, respectively. T4 RNA ligase successfully discriminated a one-base mismatch in the ligation junction, and the designed DNAzyme cleaved RNA by discerning a single-base mismatch in the cleaving site.
FEBS Letters | 2012
Ji Eun Kim; Soojin Yoon; Hyejung Mok; Woong Jung; Dong-Eun Kim
RNA‐cleaving DNAzymes were constructed to target the point mutation in the BCR–ABL transcript that causes imatinib resistance in leukemic cells. We examined the effect of 12mer peptide nucleic acids (PNAs) as facilitator oligonucleotides that bind to RNA substrate at the termini of the DNAzyme to improve DNAzyme‐mediated cleavage of full‐length RNA. When imatinib‐resistant cells were transfected with the facilitator PNA and DNAzyme, DNAzyme activity was enhanced and the cells were sensitized to imatinib treatment. Thus, facilitator PNA may be used to enhance activity of antisense oligonucleotide targeting the full‐length transcript.
Molecules | 2018
Min-Hee Kim; Dong-Min Kim; Keun-Sik Kim; Woong Jung; Dong-Eun Kim
Aptamers are single-stranded oligonucleotides that specifically bind and interact with their corresponding targets, including proteins and cells, through unique three-dimensional structures. Numerous aptamers have been developed to target cancer biomarkers with high specificity and affinity, and some are employed as versatile guiding ligands for cancer-specific drug delivery and anti-cancer therapeutics. In this review, we list the aptamers that target tumor surface biomarkers and summarize the representative applications of aptamers as agonists and antagonists that activate anti-cancer and inactivate pro-cancer biomarkers, respectively. In addition, we describe applications of aptamer-drug or aptamer-oligonucleotide conjugates that can deliver therapeutic agents, including small interfering RNAs, micro RNAs, short hairpin RNAs, and chemotherapeutic molecules, to cancer cells. Moreover, we provide examples of aptamer- conjugated nano-vehicles, in which cancer-targeting oligonucleotide aptamers are conjugated with nano-vehicles such as liposomes, micelles, polymeric nanoparticles, and quantum dots. Conjugation of aptamers with anti-cancer drugs and nano-vehicles will facilitate innovative applications of aptamer-based cancer therapeutics.
Applied Biological Chemistry | 2016
Kwang-su Park; Woong Jung; Youhoon Chong; Mi Kyoung Kim
We have reported previously that conjugation of glutamic acid at the 7-O position of quercetin could significantly enhance its biological activity. In this study, as a part of our ongoing efforts to investigate the therapeutic potential of this novel quercetin–glutamate conjugate (1), we evaluated the effect of its combination with vancomycin against Gram-negative Escherichia coli, which are not normally affected by vancomycin alone. Quercetin conjugate 1 was shown to potentiate the antibacterial activity of vancomycin against E. coli, which could be attributed to its membrane perturbation activity, but not to facilitation of the efflux pump-mediated penetration of vancomycin.
Phytotherapy Research | 2018
Sun-Hye Shin; Mi Kyoung Kim; Woong Jung; Youhoon Chong
Urokinase plasminogen activator (uPA) and its inhibitor plasminogen activator inhibitor‐1 (PAI‐1) are established independent biomarkers for high metastasis risk in breast cancer. In this study, we investigated the regulatory activity of (−)‐epigallocatechin‐3‐gallate (EGCG) and its derivatives on uPA and PAI‐1 expression and thereby their anti‐metastatic potential. EGCG showed only marginal effects on the uPA system and on the metastatic behavior of breast cancer cells (MDA‐MB‐231). However, the EGCG derivative 3e with a methyl‐substituted carbonate substituent at the 4″‐position showed potent inhibition of PAI‐1 (62%) and uPA (50%) expression. The Ras‐extracellular‐signal‐regulated kinase (ERK), p38 mitogen‐activated protein kinase (MAPK), and phosphatidylinositol‐3‐kinase (PI3K)/Akt/NF‐κB pathways, which regulate uPA and PAI‐1 expression, were also affected by 3e (25%, 45%, and 25% reduction, respectively). In line with these findings, substantial reduction in metastatic behavior of MDA‐MB‐231 cells, such as adhesion (40%), invasion (56%), and migration (40%), was observed in the presence of 3e. It is also noteworthy that, in MDA‐MB‐231 cells, 3e did not exert any beneficial effect on the expression of matric metalloprotein (MMP) 2 and 9, which indicates that the anti‐metastatic activity of 3e in MDA‐MB‐231 cells is not related to its regulation of the expression of MMPs. Taken together, we have shown that the EGCG derivative 3e could suppress the metastatic behavior of MDA‐MB‐231 cells through regulation of uPA and PAI‐1.