Prevalence of Plasmid-Mediated Quinolone Resistance and Mutations in the Gyrase and Topoisomerase IV Genes in <i>Salmonella</i> Isolated from 12 Tertiary-Care Hospitals in Korea

Jeong, Haeng Soon,Kim, Jeong A.,Shin, Jeong Hwan,Chang, Chulhun L.,Jeong, Joseph,Cho, Ji-Hyun,Kim, Mi-Na,Kim, Sunjoo,Kim, Young Ree,Lee, Chae Hoon,Lee, Kyungwon,Lee, Mi Ae,Lee, Wee Gyo,Shin, Jong Hee Mary Ann Liebert 2011 Microbial drug resistance Vol.17 No.4

Use of RNA aptamers for the modulation of cancer cell signaling.

Jeong, Sunjoo,Lee, Hee Kyu,Kim, Mee Young Humana Press 2009 METHODS IN MOLECULAR BIOLOGY -CLIFTON THEN TOTOWA- Vol.542 No.-

<P>Aptamers are in vitro evolved molecules that bind to target proteins with high affinity and specificity by adapting three-dimensional structures upon binding. Because cancer cells exhibit the activation of signaling pathways that are not usually activated in normal cells, RNA aptamers against such a cancer cell-specific signal can be useful lead molecules for cancer gene therapy. The Wnt/beta-catenin signaling pathway plays important roles in a critical initiating event in the formation of various human cancers. Because mutations in beta-catenin have been found to be responsible for human tumorigenesis, beta-catenin is the molecular target for effective anticancer therapies. Here, we describe the selection of RNA aptamers against beta-catenin/T-Cell Factor (TCF) proteins and their intracellular expression as intramers. The RNA aptamers acted as central inhibitory players for multiple oncogenic functions of beta-catenin in colon cancer cells. These data provide the proof-of-principle for the use of RNA aptamers for an effective anticancer gene therapy.</P>

Pharmacodynamic Effect of Cilostazol Plus Standard Clopidogrel Versus Double-Dose Clopidogrel in Patients With Type 2 Diabetes Undergoing Percutaneous Coronary Intervention

Jeong, Young-Hoon,Tantry, Udaya S.,Park, Yongwhi,Kwon, Tae Jung,Park, Jeong Rang,Hwang, Seok-Jae,Bliden, Kevin P.,Koh, Eun-Ha,Kwak, Choong Hwan,Hwang, Jin-Yong,Kim, Sunjoo,Gurbel, Paul A. American Diabetes Association 2012 Diabetes care Vol.35 No.11

<P><B>OBJECTIVE</B></P><P>To determine the effect of adding cilostazol (100 mg b.i.d.) to standard-dose clopidogrel (75 mg/d) (TRIPLE) compared with double-dose clopidogrel (150 mg/d) (DOUBLE) and the influence of the cytochrome P450 (<I>CYP2C19*2/*3</I>, <I>CYP3A5*3)</I>and ATP-binding cassette subfamily B1(<I>ABCB1 C3435T</I>) genetic polymorphisms in type 2 diabetes (T2DM) patients.</P><P><B>RESEARCH DESIGN AND METHODS</B></P><P>T2DM patients were treated with TRIPLE (<I>n</I> = 41) or DOUBLE (<I>n</I> = 39) after percutaneous coronary intervention. Conventional aggregometry and VerifyNow were performed at baseline and at 30 days. The primary end point was absolute change in 20-μM ADP-induced maximal platelet aggregation (ΔMPA<SUB>20</SUB>) between baseline and switching values.</P><P><B>RESULTS</B></P><P>TRIPLE versus DOUBLE showed greater ΔMPA<SUB>20</SUB> (22.9 ± 11.6 vs.12.7 ± 15.5%; difference, 10.2% [95% CI 4.2–16.3]; <I>P</I> < 0.001). Carriage of one (β coefficient, −5.4%; <I>P</I> = 0.162) and two <I>CYP2C19</I> loss-of-function allele(s) (−8.3%; <I>P</I> = 0.007) were associated with lower ΔMPA<SUB>20</SUB> in DOUBLE–treated patients, but not in TRIPLE-treated patients.</P><P><B>CONCLUSIONS</B></P><P>Among T2DM patients, adding cilostazol achieves greater platelet inhibition compared with clopidogrel (150 mg/d), which is not influenced by genetic polymorphisms.</P>

Transcriptional Regulation and Apoptosis Induction by Tcf/$\beta$-Catenin Complex in Various T-Cells

Jeong, Sunjoo,Lee, Seung-Yeon,Lee, Sun-Hee The Korean Society for Integrative Biology 2000 Korean journal of biological sciences Vol.4 No.4

The Tcf-1 (1-cell factor-1) protein binds to the T-cell specific enhancer sequences and plays an architectural role in the assembly of transcriptional machinery. One of the Tcf family proteins, Tcf-4, was found to be an important regulator for colon cancer development where it activates specific genes upon binding to $\beta$-catenin following Wnt signaling. We were interested in the transcriptional regulatory activities of Tcf-1 and Tcf-4 proteins in T-cells and colon cancer cells. Transactivation assay was developed using a reporter plasmid containing luciferase gene under the control of Tcf responsive elements. Luciferase activity was determined following co-transfection of the reporter along with Tcf-1 and/or $\beta$-catenin expressing plasmids. Transcription was significantly induced by $\beta$-catenin expression in all cells. Tcf-1 by itself did not induce transcription in the mature T-cell lines, but overexpressed Tcf-1 greatly activated transcription in the immature T-cell line. In addition, transfected $\beta$-catenin induced apoptosis, but co-transfected Tcf-1 suppressed apoptosis in HEK293 cells. These results suggest that Tcf-1 and $\beta$-catenin differently regulate transcription and apoptosis.

RNA Aptamers that Bind the Nucleocapsid Protein Contain Pseudoknots

Sunjoo Jeong,김미영 한국분자세포생물학회 2003 Molecules and cells Vol.16 No.3

In Vitro Selection and Characterization of TCF-1 Binding RNA Aptamers

Sunjoo Jeong,Seung-Yeon Lee 한국분자세포생물학회 2004 Molecules and cells Vol.17 No.1

TCF proteins are architectural transcription factors that bind to β-catenin when the Wnt signaling path-way is activated. TCF-1 is specifically expressed in T-cell lineages and its interaction with β-catenin is thought to be critical for early T-cell development. However, the mechanisms underlying activation of TCF-1 during T-cell development are not completely understood. With the aim of developing RNA aptam-ers that bind to TCF-1 and regulate its activity, we screened an RNA library consisting of random se-quences of 70 nucleotides and were able to isolate ap-tamers that bind to TCF-1 with high affinity and specificity. We employed RNase footprinting to char-acterize the RNA structures and map their binding sites for TCF-1. It is hoped that the selected aptamers will regulate TCF-1 activity in vivo, thereby providing a unique tool for modulating TCF-1 function in early T-cell development.

PI3-Kinase and PDK-1 Regulate HDAC1-mediated Transcriptional Repression of Transcription Factor NF-κB

Sunjoo Jeong,Yong Seok Choi 한국분자세포생물학회 2005 Molecules and cells Vol.20 No.2

PDK-1 activates PI3-kinase/Akt signaling and regulates fundamental cellular functions, such as growth and survival. NF-κB is involved in the induction of a variety of cellular genes affecting immunity, inflammation and the resistance to apoptosis induced by some anti-cancer drugs. Even though the crucial involvement of the PI3-kinase/Akt pathway in the anti-apoptotic activation of NF-κB is well known, the exact role of PDK-1 as well as PI3-kinase/Akt in NF-κB activation is not understood. Here we demonstrate that PDK-1 plays a pivotal role in transcriptional activation of NF-κB by dissociating the transcriptional co-repressor HDAC1 from the p65 subunit of NF-κB. The association of CBP with p65 was not directly modulated by PDK-1 or by PI3-kinase. Etoposide activated NF-κB through PI3-kinase/Akt, and the transcription activation domain (TAD) of p65 was further activated by wild-type PDK-1. Overexpression of a dominant negative PDK-1 mutant decreased etoposide-induced NF-κB transcription and further downregulated the ectopic HDAC1-mediated decrease in NF-κB transcriptional activity. Thus activation of PDK-1 relieves the HDAC1-mediated repression of NF-κB that may be related to basal as well as activated transcription by NF-κB. This effect may also explain the role of the PI3-kinase/PDK-1 pathway in the anti-apoptotic function of NF-κB associated with the chemoresistance of cancer cells.

결핵균 약제감수성 검사의 비용효율성에 관한 다기관 연구

정석훈,이대동,최재철,김선주,신정환,정윤성,이은엽,오승환,배길한,장철훈 대한감염학회 2005 감염과 화학요법 Vol.37 No.1

목적 : 우리나라에서의 결핵균 감수성 검사는 검출 균주의 일부에서만 시행되고 있다. 본 연구에서는 모든 검출 균주들에 대해서 감수성검사를 실시하면서, 진료에 필요한 결과를 충분히 제공하고 경제적이면서 현실적인 감수성검사 방안을 제시하고자 한다. 재료 및 방법 : 5개 대학병원에서 일정기간 연속적으로 의뢰된 502균주의 감수성 결과를 분석하였다. 검사결과의 해석 및 2차 약제 감수성검사의 필요성은 NCCLS approved standard M24-A의 권고 기준에 따라 판단하였다. 결과 : 최소한 1가지 이상의 약제에 내성을 보인 경우는 초치료 환자의 10% (38/363), 재치료 환자의 61%(85/139)였으며, 다약제 내성을 보인 경우는 초치료 환자의 3% (11/363), 재치료 환자의 44% (61/139)였다. NCCLS 권고에 따라 2차 약제에 대한 감수성 검사를 시행하지 않아도 되는 경우는 초치료 환자의 96%, 재치료환자의 47%였다. 결론 : 초치료 환자는 95%에서 1차 약제에 대한 검사만으로 충분하므로 필요한 경우에만 2차 약제를 추가로 검사하고 재치료 환자에서는 1, 2차 약제를 동시에 검사할 필요가 있을 것으로 생각한다. Background : The anti-mycobacterial susceptibility test is performed on only a small percentage of clinical isolates in Korea. The aim of this study is to propose an anti-mycobacterial susceptibility testing scheme, which is not only economic and practical but also fully informative to physicians. Materials and Methods : The anti-mycobacterial susceptibility test results of 502 strains, isolated from five university-affiliated hospitals, were analysed. The interpretation of the results and the need for second-line drug susceptibility test were judged according to the recommendation of NCCLS M24-A guidelines. Results : The isolates from 10% (38/363) of treatment-navie patients and 61% (85/139) of retreatment patients showed resistance to at least one of the anti-mycobactial agents; 3% (11/363) and 44% (61/139) of isolates from each group were multi-drug resistant. According to the recommendation by NCCLS, the percentage of patients not needing the susceptibility test results for second-line drugs were 96% for treatment-naive and 47% for re-treatment patients. Conclusion : Since the susceptibility test against first-line drug is sufficient for 95% of treatment-navie patients with tuberculosis patients, susceptibility test against second-line drugs may be performed only when it is necessary. As for the re-treatment patients with tuberculosis, susceptibility test for both first-line and second-line drugs should be performed simultaneously.

SR Proteins: Binders, Regulators, and Connectors of RNA

Jeong, Sunjoo Korean Society for Molecular and Cellular Biology 2017 Molecules and cells Vol.40 No.1

Serine and arginine-rich (SR) proteins are RNA-binding proteins (RBPs) known as constitutive and alternative splicing regulators. As splicing is linked to transcriptional and post-transcriptional steps, SR proteins are implicated in the regulation of multiple aspects of the gene expression program. Recent global analyses of SR-RNA interaction maps have advanced our understanding of SR-regulated gene expression. Diverse SR proteins play partially overlapping but distinct roles in transcription-coupled splicing and mRNA processing in the nucleus. In addition, shuttling SR proteins act as adaptors for mRNA export and as regulators for translation in the cytoplasm. This mini-review will summarize the roles of SR proteins as RNA binders, regulators, and connectors from transcription in the nucleus to translation in the cytoplasm.

ERp16, an endoplasmic reticulum-resident thiol-disulfide oxidoreductase: biochemical properties and role in apoptosis induced by endoplasmic reticulum stress.

Jeong, Woojin,Lee, Duck-Yeon,Park, Sunjoo,Rhee, Sue Goo American Society for Biochemistry and Molecular Bi 2008 The Journal of biological chemistry Vol.283 No.37

<P>We have characterized the properties and putative role of a mammalian thioredoxin-like protein, ERp16 (previously designated ERp18, ERp19, or hTLP19). The predicted amino acid sequence of the 172-residue human protein contains an NH(2)-terminal signal peptide, a thioredoxin-like domain with an active site motif (CGAC), and a COOH-terminal endoplasmic reticulum (ER) retention sequence (EDEL). Analyses indicated that the mature protein (comprising 146 residues) is generated by cleavage of the 26-residue signal peptide and is localized in the lumen of the ER. Biochemical experiments with the recombinant mature protein revealed it to be a thioldisulfide oxidoreductase. Its redox potential was about -165 mV; its active site cysteine residue Cys(66) was nucleophilic with a pK(a) value of approximately 6.6; it catalyzed the formation, reduction, and isomerization of disulfide bonds, with the unusual CGAC active site motif being responsible for these activities; and it existed as a dimer and underwent a redox-dependent conformational change. The observations that the redox potential of ERp16 (-165 mV) was within the range of that of the ER (-135 to -185 mV) and that ERp16 catalyzed disulfide isomerization of scrambled ribonuclease A suggest a role for ERp16 in protein disulfide isomerization in the ER. Expression of ERp16 in HeLa cells inhibited the induction of apoptosis by agents that elicit ER stress, including brefeldin A, tunicamycin, and dithiothreitol. In contrast, expression of a catalytically inactive mutant of ERp16 potentiated such apoptosis, as did depletion of ERp16 by RNA interference. Our results suggest that ERp16 mediates disulfide bond formation in the ER and plays an important role in cellular defense against prolonged ER stress.</P>