• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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• pp.227.2-227.2
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• 2003

In the situation of high bacterial resistance to antibiotics in Korea, to assess diffusion of methicillin-resistant Staphylococcus aureus (MRSA) and levels of bacterial resistance to antibiotics in community, we monitored antibiotic resistance of S. aureus isolates from healthy volunteers of community. (omitted)

• Molecules and Cells
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• 제42권3호
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• pp.237-244
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• 2019

Understanding the mechanisms of cancer drug resistance is a critical challenge in cancer therapy. For many cancer drugs, various resistance mechanisms have been identified such as target alteration, alternative signaling pathways, epithelial-mesenchymal transition, and epigenetic modulation. Resistance may arise via multiple mechanisms even for a single drug, making it necessary to investigate multiple independent models for comprehensive understanding and therapeutic application. In particular, we hypothesize that different resistance processes result in distinct gene expression changes. Here, we present a web-based database, CDRgator (Cancer Drug Resistance navigator) for comparative analysis of gene expression signatures of cancer drug resistance. Resistance signatures were extracted from two different types of datasets. First, resistance signatures were extracted from transcriptomic profiles of cancer cells or patient samples and their resistance-induced counterparts for >30 cancer drugs. Second, drug resistance group signatures were also extracted from two large-scale drug sensitivity datasets representing ~1,000 cancer cell lines. All the datasets are available for download, and are conveniently accessible based on drug class and cancer type, along with analytic features such as clustering analysis, multidimensional scaling, and pathway analysis. CDRgator allows meta-analysis of independent resistance models for more comprehensive understanding of drug-resistance mechanisms that is difficult to accomplish with individual datasets alone (database URL: http://cdrgator.ewha.ac.kr).

• International journal of advanced smart convergence
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• 제11권4호
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• pp.227-239
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• 2022

Purpose: In our study, in order to find lactic acid bacteria (LAB) with multi-drug resistance to antibiotics, we isolated 140 strains from 15 types of kimchi commercially available in Korea and 20 types of Kimchi made at home from January to December in 2016, and investigated their H₂O₂ generating ability and multi-drug resistance to antibiotics. Methods: In order to observe the H₂O₂ generation ability of LAB, we performed the experiment with methods such as Rabe, Hillier, and Kang. To test the antibacterial susceptibility of LAB, we used the disc agar diffusion method using MRS agar (Difco, USA) according to the CLSI and WHO test methods. There are 18 types of antibiotic discs used. Results: Out of the total numbers of 140 strains, 6 strains of Ent. Faecium, 25 strains of L. plantarum, 1 strain of L. rhamnosus, 3 strains of L. sakei, 1 strain of L. acidophilus, 1 strains St. thermophilus, and 7 of unidentified strains generated H₂O₂. The antibiotic susceptibility of Ent. Faecium indicated SXT, OX, NA, and E; and the antibiotic susceptibility of L. plantarum indicated NA; and the antibiotic susceptibility of St. thermophilus indicated NA, CC, RA, CTT, CM, and P ; and the antibiotic susceptibility of L. rhamnosus indicated SXT, VA, NA and CTT; and the antibiotic susceptibility of 6 strains of L. sakei indicated SXT, OX, NOR, NA, CTT and CIP, all indicating antibiotic resistance. In the case of multi-drug resistance to antibiotics for 53 strains of L. antarum, 8-drug resistance was the most common with 25 strains, followed by 7-drug-resistant strains with 18 strains, 9-drug-resistant strains with 4 strains, 6-drug-resistant strains with 3 strains, 5-drug-resistant strains with 2 strains, and 17-drug-resistant strains with 1 strain. In the case of multi-drug resistance to antibiotics for Ent. Faecium 27 strains, 9-drug resistance was most commonly identified as 9 strains, 8-drug resistance was identified as 6 strains, 7- and 11 drug resistances were identified as 4 strains each, and 4- and 6-drug resistances were identified as 1 strain each. Conclusion: Ent. Faecium, L. plantarum, L. rhamnosus, L. sakei, and St. thermophilus, shown to have anantibacterial activity in previous studies on LAB and shown to have and H₂O₂ generating ability, antibiotic resistance and multi-drug resistance in this study, are expected to be able to play an excellent role for long-term inpatients to use as an alternative to antibiotics and to cope with emerging antibiotic resistance.

• Tuberculosis and Respiratory Diseases
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• 제64권2호
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• pp.95-101
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• 2008

연구배경: 결핵의 치료력이 없는 결핵환자에서 발생하는 초회 약제내성은 결핵관리에 있어서 심각한 문제이다. 그러나 우리나라, 특히 민간의료기관에서 치료받는 폐결핵환자들의 초회 약제내성률에 대해서 잘 알려져 있지 않다. 본 연구에서는 천안지방의 한 3차병원에서 폐결핵환자들의 초회 약제내성률과 약제내성의 위험요소에 대해서 알아보았다. 방법: 2005년 9월부터 2007년 9월까지 단국대학교병원에서 객담 결핵균 배양검사 양성인 초치료 폐결핵환자 모두에 대해서 일차약과 이차약에 대한 약제감수성 검사를 시행하고 초회 약제내성의 양상과 함께 약제내성의 위험요소을 분석하였다. 또한 약제감수성 검사 결과가 치료 처방에 미치는 영향을 분석하였다. 결과: 총 156명의 초치료 폐결핵 환자에 대해서 약제 감수성 검사를 시행하였는데 한 가지 이상의 약제에 내성을 보인 환자는 21명(15.6%)이었으며 이소니아지드와 리팜핀에 동시 내성을 보이는 다제내성 환자는 1명(0.6%)이었다. 임상소견 중 초회 약제내성을 예측할 수 있는 독립적인 위험요소는 없었다. 약제감수성 검사 결과에 의해 15명(9.6%)의 환자에서 치료처방의 변경이 있었다. 결론: 폐결핵에서 초회 약제내성은 흔히 관찰되며 초 치료 폐결핵환자에서 약제감수성 검사는 환자치료에 도움이 된다.

• Asian Pacific Journal of Cancer Prevention
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• 제13권11호
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• pp.5619-5625
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• 2012

Gastric carcinoma is a leading cause of cancer death in the world and multi-drug resistance (MDR) is an essential aspect of gastric carcinoma chemotherapy failure. Recent studies have shown that integrin-linked kinase (ILK) is involved in metastasis of human tumors, expression silencing of ILK inhibiting the metastasis of several types of cultured human cancer cells. However, the role and potential mechanism of ILK to reverse the multi-drug resistance in human gastric carcinoma is not fully clear. In this report, we focused on roles of expression silencing of ILK in multi-drug resistance reversal of human gastric carcinoma SGC7901/DDP cells, including increased drug sensitivity to cisplatin, cell apoptosis rates, and intracellular accumulation of Rhodamine-123, and decreased mRNA and protein expression of multi-drug resistance gene (MDR1), multi-drug resistance-associated protein (MRP1), excision repair cross-complementing gene 1 (ERCC1), glutathione S-transferase -${\pi}$ (GST-${\pi}$) and RhoE, and transcriptional activation of AP-1 and NF-${\kappa}B$ in ILK silenced SGC7901/DDP cells. We also found that there was a decreased level of p-Akt and p-ERK. The results indicated that ILK might be used as a potential therapeutic strategy to combat multi-drug resistance through blocking PI3K-Akt and MAPK-ERK pathways in human gastric carcinoma.

• Biomolecules & Therapeutics
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• 제18권4호
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• pp.375-385
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• 2010

Conventional cancer chemotherapy is seriously limited by tumor cells exhibiting multidrug resistance (MDR), which is caused by changes in the levels or activity of membrane transporters that mediate energy-dependent drug efflux and of proteins that affect drug metabolism and/or drug action. Cancer scientists and oncologists have worked together for some time to understand anticancer drug resistance and develop pharmacological strategies to overcome such resistance. Much focus has been on the reversal of the MDR phenotype by inhibition of ATP-binding cassette (ABC) drug transporters. ABC transporters are a family of transporter proteins that mediate drug resistance and low drug bioavailability by pumping various drugs out of cells at the expense of ATP hydrolysis. Many inhibitors of MDR transporters have been identified, and though some are currently undergoing clinical trials, none are in clinical use. Herein, we briefly review the status of MDR in human cancer, explore the pathways of MDR in chemotherapy, and outline recent advances in the design and development of MDR modulators.

• Asian Pacific Journal of Cancer Prevention
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• 제14권11호
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• pp.6757-6760
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• 2013

Gastric cancer is one of the most frequently occurring malignancies in the world. Development of multiple drug resistance (MDR) to chemotherapy is known as the major cause of treatment failure for gastric cancer. Multiple drug resistance 1/P-glycoprotein (MDR1/p-gp) contributes to drug resistance via ATP-dependent drug efflux pumps and is overexpressed in many solid tumors including gastric cancer. To investigate the role of MDR1 knockdown on drug resistance reversal, we knocked down MDR1 expression using shRNA in drug resistant gastric cancer cells and examined the consequences with regard to adriamycin (ADR) accumulation and drug-sensitivity. Two shRNAs efficiently inhibited mRNA and protein expression of MDR1 in SGC7901-MDR1 cells. MDR1 knockdown obviously decreased the ADR accumulation in cells and increased the sensitivity to ADR treatment. Together, our results revealed a crucial role of MDR1 in drug resistance and confirmed that MDR1 knockdown could reverse this phenotype in gastric cancer cells.

• Tuberculosis and Respiratory Diseases
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• 제58권3호
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• pp.243-247
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• 2005

연구배경 : 한국에서 결핵환자의 유병률은 지속적으로 감소하고 있으나 약제에 대한 내성은 치료 실패의 중요한 요인이다. 국가적인 조사가 시행되지 않는 현 시점에서 지속적인 내성률 조사가 더욱 필요하다. 이에 저자들은 최근 4년간 서울 소재 한 대학병원에서 조사된 결핵균의 내성률 및 관련된 위험인자를 조사하였다. 대상 및 방법 : 1999년 3월부터 2003년 3월까지 한양대학교 의료원에서 치료 받은 결핵환자 중 결핵 배양 및 감수성 검사를 시행한 239명을 대상으로 하였다. 결 과 : 239명 중 한가지 이상의 약제에 내성을 보인 경우는 25명(21.8%)였고, 다제 내성 결핵은 30명(12.6%)이었다. INH, RFP, EMB, SM, PZA의 내성률은 각각 18.4%, 13.8%, 11.7%, 6.7%, 8.4%였다. 과거 결핵 치료력이 있는 환자는 90명이었으며 이들 중 약제 내성률은 36.7%, 다제 내성률은 25.6%였다. 약제 내성을 보인 환자의 63.5%는 과거 치료력이 있었으며 약제 감수성군의 과거 치료력은 30.5%였다. 결 론 : 서울에 소재한 한 대학병원에서 조사된 결핵 내성률은 21.8%, 다제 내성 결핵의 비율은 12.6%였다. 과거 결핵 치료력이 있는 경우에 약제 내성률이 높았다.

• Archives of Pharmacal Research
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• 제29권12호
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• pp.1067-1073
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• 2006

Cisplatin, a platinum coordinated complex, is a widely used antineoplastic agent for the treatment of metastatic tumors of the testis, metastatic ovarian tumors, lung cancer, advanced bladder cancer and many other solid tumors. The cytotoxic action of the drug is often thought to be associated with its ability to bind DNA to form cisplatin-DNA adducts. The development of resistance to cisplatin during treatment is common and constitutes a major obstacle to the cure of sensitive tumors. Although to understand the clinically relevant mechanisms of resistance, many studies have been aimed at clarifying the biochemical/molecular alterations of cisplatin-resistance cells, these studies did not conclusively identify the basis of cellular resistance to cisplatin. In this review, cisplatin resistance was discussed in terms of the relevant transporters, such as copper transporters (CTRs), organic cation transporters (OCTs) and multi-drug resistance related transporters (MDRs). These transporters seem to be contributed to cisplatin resistance through the reduction of drug accumulation in the cell. Better understanding the mechanism of cisplatin resistance associated with transporters will provide the useful informations for overcoming the cisplatin resistance.

• Asian Pacific Journal of Cancer Prevention
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• 제16권18호
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• pp.8067-8073
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• 2016

Background: Long non-coding RNAs (lncRNAs) are emerging as key players in gene expression that govern cell developmental processes, and thus contributing to diseases, especially cancers. Many studies have suggested that aberrant expression of lncRNAs is responsible for drug resistance, a substantial obstacle for cancer therapy. Drug resistance not only results from individual variations in patients, but also from genetic and epigenetic differences in tumors. It is reported that drug resistance is tightly modulated by lncRNAs which change the stability and translation of mRNAs encoding factors involved in cell survival, proliferation, and drug metabolism. In this review, we summarize recent advances in research on lncRNAs associated with drug resistance and underlying molecular or cellular mechanisms, which may contribute helpful approaches for the development of new therapeutic strategies to overcome treatment failure.