• Proceedings of the Korean Society for Bioinformatics Conference
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• 2004.11a
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• pp.150-157
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• 2004

microRNA (miRNA)는 21-25 nucleotide (nt)의 single-stranded RNA 분자로서 mRNA의 3' untranslated region (3' UTR)에 상보적으로 결합하여 유전자 발현을 제어하는 새로운 조절물질이다. 지금까지 실험을 통해 수백 개의 miRNA가 알려져 있으나, miRNA에 의해 조절되는 target 유전자는 실험상의 어려움으로 아직까지 거의 알려지지 않았다. miRNA는 서열의 길이가 짧고 target과 느슨한 상보적 결합을 하기 때문에 기존의 서열 비교 방법으로 miRNA의 target을 찾는 것은 쉬운 일이 아니다. 본 논문은 신경망을 이용하여 Caenorhabditis elegans mRNA의 3' UTR에서 miRNA가 결합하는 영역을 예측하였다. 신경망은 복잡한 비선형 데이터를 잘 분리해내고 불완전하고 잡음이 많은 입력에 강하기 때문에 miRNA target 예측에 적합하다. miRNA와 mRNA의 결합 영역을 다양하게 분석하였고 민감도 0.59, 특수도 0.99의 성능을 갖는 신경망을 구현하였다. 신경망 입력 값을 달리하여 각각의 특성이 결과에 미치는 영향을 분석하였고 기존 예측 방법에 의한 결과와 비교하여 성능을 평가하였다.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.7
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• pp.4127-4130
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• 2013

MicroRNA-16 (miR-16) has been demonstrated to regulate proliferation and apoptosis in many types of cancers, but its biological function in bladder cancer remains unknown. Here, we found expression of miR-16 to be downregulated in bladder cancer in comparison with the adjacent normal tissues. Enforced expression of miR-16 was able to inhibit cell proliferation in TCHu-1 cells, in line with results for miR-16 antisense oligonucleotides (antisense miR-16). At the molecular level, our results further revealed that cyclin D1 expression was negatively regulated by miR-16. Therefore, the data reported here demonstrate that miR-16 is an important regulator in bladder cancer, which will contribute to better understanding of important mis-regulated miRNAs.

• BMB Reports
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• v.50 no.4
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• pp.158-159
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• 2017

MicroRNAs (miRNAs) regulate gene expression by guiding the Argonaute (Ago)-containing RNA-induced silencing complex (RISC) to specific target mRNA molecules. It is well established that miRNAs are stabilized by Ago proteins, but the molecular features that trigger miRNA destabilization from Ago proteins remain largely unknown. To explore the molecular mechanisms of how targets affect the stability of miRNAs in human Ago (hAgo) proteins, we employed an in vitro system that consisted of a minimal hAgo2-RISC in HEK293T cell lysates. Surprisingly, we found that miRNAs are drastically destabilized by binding to seedless, non-canonical targets. We showed that miRNAs are destabilized at their 3' ends during this process, which is largely attributed to the conformational flexibility of the L1-PAZ domain. Based on these results, we propose that non-canonical targets may play an important regulatory role in controlling the stability of miRNAs, instead of being regulated by miRNAs.

• Korean Journal of Agricultural and Forest Meteorology
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• v.2 no.1
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• pp.24-30
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• 2000

This paper is to introduce distinctive trends in Agrometeorological Information(AgMI) these days, as well as newly emerging technologies from advanced sciences that are promising to enhance production and dissemination of AgMI in the future. The basic concept and important characteristics of AgMI were described either in general or in technical terms. Then AgMI was rather arbitrarily classified here into several groups, simply to show the diversity of AgMI resources available and technologies employed. The production, management, dissemination and communication of AgMI are envisaged to some extent together with the introduction of current status of AgMI production in Korea. Finally a couple of personal prospects on AgMI for agricultural applications are listed in terms of applicable subjects in Agricultural activities, current practicing cases in Korea and future perspectives for sustainable agriculture.

• Tuberculosis and Respiratory Diseases
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• v.77 no.2
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• pp.60-64
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• 2014

MicroRNAs (miRNAs) are a class of small noncoding RNAs that modulate target gene activity, and are aberrantly expressed in most types of cancer as well in lung cancer. A miRNA can potentially target a diverse set of mRNAs; further, it plays a critical role in lung tumorigenesis as well as affects patient outcome. Previous studies focused mainly on abnormal miRNAs expressions in lung cancer tissues. Interestingly, circulating miRNAs were identified in human plasma and serum in 2008. Since then, considerable effort has been directed to the study of circulating miRNAs as one of the biomarkers of lung cancer. miRNAs expression of tissues and blood in lung cancer patients is being analyzed by more researchers. Recently, to overcome the high false-positivity of low-dose chest computed tomography scan, miRNAs in lung cancer screening are being investigated. This article summarizes the recent researches regarding clinical applications of miRNAs in the diagnosis and management of lung cancer.

• Molecules and Cells
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• v.40 no.3
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• pp.195-201
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• 2017

In this study, qRT-PCR was employed to identify that miR-186 expression level in NSCLC tissues are highly associated with lymph node metastasis. In addition, through the application of western blotting, luciferase assay and qRT-PCR, it was found that miR-186 targeted 3'UTR of cdc42 mRNA and down-regulated cdc42 protein level in a post-transcriptional manner. Transwell assay indicated that cdc42 partially reversed the effect of miR-186 mimics. Besides, miR-186 was proved to regulate EMT by influencing biomarkers of this process and cell adhesion ability. Thus, miR-186 is a potential target for NSCLC therapy. miR-186 is proposed to be one of tumor-suppressors and may serve as a therapeutic target in NSCLC treatment.

• Molecules and Cells
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• v.37 no.12
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• pp.873-880
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• 2014

In our previous study, miRNA-183, a miRNA in the miR-96-182-183 cluster, was significantly over-expressed in esophageal squamous cell carcinoma (ESCC). In the present study, we explored the oncogenic roles of miR-183 in ESCC by gain and loss of function analysis in an esophageal cancer cell line (EC9706). Genome-wide mRNA micro-array was applied to determine the genes that were regulated directly or indirectly by miR-183. 3'UTR luciferase reporter assay, RT-PCR, and Western blot were conducted to verify the target gene of miR-183. Cell culture results showed that miR-183 inhibited apoptosis (p < 0.05), enhanced cell proliferation (p < 0.05), and accelerated G1/S transition (p < 0.05). Moreover, the inhibitory effect of miR-183 on apoptosis was rescued when miR-183 was suppressed via miR-183 inhibitor (p < 0.05). Western blot analysis showed that the expression of programmed cell death 4 (PDCD4), which was predicted as the target gene of miR-183 by microarray profiling and bioinformatics predictions, decreased when miR-183 was over-expressed. The 3'UTR luciferase reporter assay confirmed that miR-183 directly regulated PDCD4 by binding to sequences in the 3'UTR of PDCD4. Pearson correlation analysis further confirmed the significant negative correlation between miR-183 and PDCD4 in both cell lines and in ESCC patients. Our data suggest that miR-183 might play an oncogenic role in ESCC by regulating PDCD4 expression.

• Journal of Gastric Cancer
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• v.16 no.4
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• pp.221-229
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• 2016

Purpose: Dysregulated microRNAs (miRNAs) can contribute to cancer development by leading to abnormal proliferation of cells, apoptosis, and differentiation. Although several miRNAs that are related to gastric cancer have been identified, the reported results have been inconsistent. The aim of this study was to determine miRNA expression profiles and validate miRNAs up- and down-regulated in gastric cancer. Materials and Methods: We evaluated 34 primary gastric cancer tissues and paired adjacent nontumorous gastric tissues. Total RNA was extracted, and low-molecular-weight RNAs (<200 nucleotides) were isolated for further analysis. Two pairs of tissues were processed for GeneChip microarray analysis, and the identified up- and down-regulated miRNAs were validated by real-time quantitative polymerase chain reaction (qPCR). Results: In the set of differentially expressed miRNAs, 5 were overexpressed by more than 2 fold, and 5 were reduced by 2 fold or less in gastric cancer tissues compared with normal gastric tissues. Four of these miRNAs (miR-196b-5p, miR-375, miR-483-5p, and miR-486-5p) were then validated by qPCR, and the relative expression levels of 2 miRNAs (miR-196b-5p and miR-375) were significantly different between cancer and normal tissues. Conclusions: Our results revealed that the expression of miR-196b-5p and miR-375 significantly correlates with gastric cancer. These miRNAs could therefore serve as diagnostic biomarkers of gastric cancer.

• Journal of Life Science
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• v.24 no.7
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• pp.798-803
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• 2014

Cathepsin D (CtsD), an aspartyl peptidase, is involved in apoptosis, resulting in the release of cytochrome C from mitochondria in cells. Here, we investigated microRNA regulation of CtsD expression in 3T3-L1 cells First, we observed the expression of CtsD in cells in response to doxorubicin (Dox). As expected, the level of CtsD mRNA was increased in 3T3-L1 cells exposed to Dox in a dose-dependent manner. Cellular viability of ectopically expressed CtsD cells was also decreased. Next, we used the miRanda program to search for particular microRNA targeting CtsD. MiR-145 was selected as a putative controller for CtsD because miR-145 had a high mirSVR score. In a reporter assay, the luciferase activity of cells containing the CtsD 3'-UTR region was decreased in cells transfected with miR-145 mimic compared to that of a control. The level of CtsD expression was down-regulated in preadipocytes ectopically expressing miR-145 and up-regulated by an miR-145 inhibitor. Cells also suppressed miR-145 expression when exposed to Dox. The miR-145 inhibitor reduced the cellular viability of 3T3-L1 cells. Taken together, these data suggest that miR-145 regulates CtsD-mediated cell death in adipocytes. These findings may have valuable implications concerning the molecular mechanism of CtsD-mediated cell death in obesity, suggesting that CtaD could be a useful therapeutic tool for the prevention and treatment of obesity by regulating fat cell numbers.

• Journal of the Korean Society of Radiology
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• v.13 no.1
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• pp.21-29
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• 2019

The purpose of this study was to compare the MI using SonoVue along with different machines output and to infer the meaning of the signal difference under the same condition. All of the comparative instruments showed strong signal values at early stage as MI value increased. Over time, the inter-instrumental signal values showed signal attenuation under all conditions except for 10 min of the condition of MI 0.1 of RS85A. E9 and EPIQ7 showed signal degradation due to microbubble collapse over time at all MI values. In the comparison of equipment, the signal strengths of MI 0.1, 0.2, and 0.4 were high in order of EPIQ7, RS85A and E9. In the quantitative analysis, there were statistically significant from the SNR and CNR that were obtained from RS85A and E9 (P-value<0.05). In the quantitative analysis, Epiq7 was statistically significant except for CNR as the MI value was changed In the contrast-enhanced ultrasound, even though MI value was low (MI <0.05), it will be helpful for diagnosis, controlling the MI and scan time because a difference in signal intensity was shown between the three machines.