• Journal of Korean Neurosurgical Society
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• v.53 no.2
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• pp.72-76
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• 2013

Objective : Cerebral aneurysm (CA) is an important acquired cerebrovascular disease that can cause catastrophic results. MicroRNAs (miRNAs) are small non-coding RNAs, playing essential roles in modulating basic physiologic and pathological processes. Currently, evidences have been established about biologic relationship between miRNAs and abdominal aortic aneurysms. However, biologic roles of miRNAs in CA formation have not been explained yet. We employed microarray analysis to detect and compare miRNA expression profiles in late stage of CA in rat model. Methods : Twenty-six, 7-week-old male Sprague-Dawley rats underwent a CA induction procedure. The control animals (n=11) were fed a normal diet, and the experimental animals (n=26) were fed a normal diet with 1% normal saline for 3 months. Then, the rats were sacrificed, their cerebral arteries were dissected, and the five regions of aneurysmal dilation on the left posterior communicating artery were cut for miRNA microarrays analysis. Six miRNAs (miRNA-1, miRNA-223, miRNA-24-1-5p, miRNA-551b, miRNA-433, and miRNA-489) were randomly chosen for validation using real-time quantitative PCR. Results : Among a set of differentially expressed miRNAs, 14 miRNAs were over-expressed more than 200% and 6 miRNAs were down-expressed lower than 50% in the CA tissues. Conclusion : The results show that miRNAs might take part in CA formation probably by affecting multiple target genes and signaling pathways. Further investigations to identify the exact roles of these miRNAs in CA formation are required.

• Molecules and Cells
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• v.37 no.5
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• pp.412-417
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• 2014

It has been reported that exogenously introduced micro-RNA (exo-miRNA) competes with endogenously expressed miRNAs (endo-miRNAs) in human cells, resulting in a detectable upregulation of mRNAs with endo-miRNA target sites (TSs). However, the detailed mechanisms of the competition between exo- and endo-miRNAs remain uninvestigated. In this study, using 74 microarrays that monitored the whole-transcriptome response after introducing miRNAs or siRNAs into HeLa cells, we systematically examined the derepression of mRNAs with exo- and/or endo-miRNA TSs. We quantitatively assessed the effect of the number of endo-miRNA TSs on the degree of mRNA derepression. As a result, we observed that the number of endo-miRNA TSs was significantly associated with the degree of derepression, supporting that the derepression resulted from the competition between exo- and endo-miRNAs. However, when we examined whether the site proficiency of exo-miRNA TSs could also influence mRNA derepression, to our surprise, we discovered a strong positive correlation. Our analysis indicates that site proficiencies of both exo- and endo-miRNA TSs are important determinants for the degree of mRNA derepression, implying that the derepression of mRNAs in response to exo-miRNA is more complex than that currently perceived. Our observations may lead to a more complete understanding of the detailed mechanisms of the competition between exo- and endo-miRNAs and to a more accurate prediction of miRNA targets. Our analysis also suggests an interesting hypothesis that long 3'-UTRs may function as molecular buffer against gene expression regulation by individual miRNAs.

• Genomics & Informatics
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• v.14 no.3
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• pp.112-124
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• 2016

Solid tumor is generally observed in tissues of epithelial or endothelial cells of lung, breast, prostate, pancreases, colorectal, stomach, and bladder, where several genes transcription is regulated by the microRNAs (miRNAs). Argonaute (AGO) protein is a family of protein which assists in miRNAs to bind with mRNAs of the target genes. Hence, study of the binding mechanism between AGO protein and miRNAs, and also with miRNAs-mRNAs duplex is crucial for understanding the RNA silencing mechanism. In the current work, 64 genes and 23 miRNAs have been selected from literatures, whose deregulation is well established in seven types of solid cancer like lung, breast, prostate, pancreases, colorectal, stomach, and bladder cancer. In silico study reveals, miRNAs namely, miR-106a, miR-21, and miR-29b-2 have a strong binding affinity towards PTEN, TGFBR2, and VEGFA genes, respectively, suggested as important factors in RNA silencing mechanism. Furthermore, interaction between AGO protein (PDB ID-3F73, chain A) with selected miRNAs and with miRNAs-mRNAs duplex were studied computationally to understand their binding at molecular level. The residual interaction and hydrogen bonding are inspected in Discovery Studio 3.5 suites. The current investigation throws light on understanding miRNAs based gene silencing mechanism in solid cancer.

• Plant Biotechnology Reports
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• v.3 no.2
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• pp.111-126
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• 2009

MicroRNAs (miRNAs) are endogenous, non-coding, small RNA molecules consisting of 21-24 nucleotides (nts) that regulate target genes at the posttranscriptional level in plants and animals. In plants, miRNAs negatively regulate target mRNAs containing a highly complementary sequence by either mRNA cleavage or translational repression. MiRNAs are processed from single-stranded precursors containing stem-loop structures by a Dicer-like enzyme and are loaded into silencing complexes, where they act on target mRNAs. Although plant miRNAs were first reported in Arabidopsis 10 years later than animal miRNAs, numerous miRNAs have since been identified from various land plants ranging from mosses to flowering plants, and their roles in diverse aspects of plant developmental processes have been characterized. Furthermore, most of the annotated plant miRNAs are evolutionarily conserved in various plants. In particular, recent functional studies using Arabidopsis mutants have contributed a great deal of information towards establishing a framework for understanding miRNA biogenesis and functional roles. Extensive appraisal of miRNA-directed regulation during a wide array of plant development and plant responses to environmental conditions has confirmed the versatile roles of miRNAs as a key component of plant molecular biology.

• Journal of Oral Medicine and Pain
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• v.44 no.1
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• pp.25-30
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• 2019

Purpose: The exact causes of burning mouth syndrome (BMS) is unclear so far. There are many studies to elucidate the relation between oral disease and genetic predisposition. In this study, we first tried to investigate salivary exosomal genetic components that could play an important role for diagnosing and elucidating the progression of BMS. Methods: We compared salivary exosomal micro RNAs (miRNAs) of BMS Patients to those of control using next generation sequencing (NGS). Unstimulated whole saliva from 15 patients with BMS and 10 control subjects were divided into two sets. Isolated exosomes and their total RNAs were subject to NGS for the screening of miRNAs. Results: There were up-regulated 10 exosomal miRNAs (hsa-miR-1273h-5p, hsa-miR-1273a, hsa-miR-1304-3p, hsa-miR-4449, hsa-miR-1285-3p, hsa-miR-6802-5p, hsa-miR-1268a, hsa-miR-1273d, hsa-miR-1273f, and hsa-miR-423-5p) and down-regulated 18 exosomal miRNAs (hsa-miR-27b-3p, hsa-miR-16-5p, hsa-miR-186-5p, hsa-miR-142-3p, hsa-miR-141-3p, hsa-miR-150-5p, hsa-miR-374a-5p, hsa-miR-93-5p, hsa-miR-29c-3p, hsa-miR-29a-3p, hsa-miR-148a-3p, hsa-miR-22-3p, hsa-miR-27a-3p, hsa-miR-424-5p, hsa-miR-19b-3p, hsa-miR-99a-5p, hsa-miR-548d-3p, and hsa-miR-19a-3p) in BMS patients comparing with those of control subjects. Conclusions: We show that there are 28 differential expression of miRNAs between the patients with BMS and those of control subjects. The specific function of indicated miRNAs should be further elucidated.

• The Korea Journal of Herbology
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• v.34 no.6
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• pp.71-78
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• 2019

Objective : The purpose of the study was to identify expression profiling of miRNAs associated with cancers after treating allergen-removed Rhus Verniciflua Stokes and allergen-removed Rhus Verniciflua Stokes fumigaed Angelica gigas on leukemia cell lines. Methods : miRNA expression has been analyzed using miRNA array method through denaturation and hybridization after isolating the total RNA from leukemic cell line treated with 100 ㎍/㎖ of aRVS and aRVS-A each. Microarray expressions were interpreted as 'significant' on miRNAs when decreased less than 0.5 fold or increased more than 1.5 fold compared with the control group. Results : Among 158 miRNAs in total, 32 miRNAs were significantly presented in miRNAs expression. miRNA has been activated with a variety of genes for predicted targets, and the overexpressed miRNAs were categorized according to proliferation and metastasis of cancer in this study. The findings were reported that seven miRNAs (let-7b, miR-193a-5p, 296-3p, 26a, 22, 124a, 92b) showed significant expressions on proliferation and growth, seven miRNAs (miR-193a-5p, 26a, 200c, 183, 124a, 198, 210) presented meaningful expressions on invasion and metastasis, two miRNAs (let-7b, miR-210) were highly expressed on angiogenesis, five miRNAs (let-7b, miR-26a, 181d, 181c, 296-5p) related with apoptosis, and six miRNAs (let-7b, miR-200c, 183, 370, 124a, 191) were associated with prognosis of cancer and early diagnostic factors for cancer. Conclusion : The mechanism of miRNA takes a role in diagnosis, treatment, and prognotic factors for cancer as well. This study suggested that further detailed research on overexpression of specific miRNA should be carried out continuously in the future.

• BMB Reports
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• v.44 no.1
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• pp.28-33
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• 2011

MicroRNAs are potential key regulators in mesenchymal stem cells chondrogenic differentiation. However, there were few reports about the accurate effects of miRNAs on chondrogenic differentiation. To investigate the mechanisms of miRNAs-mediated regulation during the process, we performed miRNAs microarray in MSCs at four different stages of TGF-${\beta}3$-induced chondrogenic differentiation. We observed that eight miRNAs were significantly up-regulated and five miRNAs were downregulated. Interestingly, we found two miRNAs clusters, miR-143/145 and miR-132/212, kept on down-regulation in the process. Using bioinformatics approaches, we analyzed the target genes of these differentially expressed miRNAs and found a series of them correlated with the process of chondrogenesis. Furthermore, the qPCR results showed that the up-regulated (or down-regulated) expression of miRNAs were inversely associated with the expression of predicted target genes. Our results first revealed the expression profiles of miRNAs in chondrogenic differentiation of MSCs and provided a new insight on complicated regulation mechanisms of chondrogenesis.

• Genomics & Informatics
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• v.12 no.4
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• pp.261-267
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• 2014

MicroRNAs (miRNAs) are known for their role in mRNA silencing via interference pathways. Repetitive elements (REs) share several characteristics with endogenous precursor miRNAs. In this study, 406 previously identified and 1,494 novel RE-derived miRNAs were sorted from the GENCODE v.19 database using the RepeatMasker program. They were divided into six major types, based on their genomic structure. More novel RE-derived miRNAs were confirmed than identified as RE-derived miRNAs. In conclusion, many miRNAs have not yet been identified, most of which are derived from REs.

• International Journal of Oral Biology
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• v.45 no.3
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• pp.134-142
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• 2020

Colon cancer is one of the most common malignant tumors, but there are still a few validated biomarkers of colon cancer. Exosome-mediated microRNAs (miRNAs) have been recognized as potential biomarkers in cancers, and miRNAs can regulate a variety of genes. Recently, Fusobacterium nucleatum was discovered in the tissues of human colon cancer patients. Its role in colon cancer was highlighted. F. nucleatum may contribute to the progression of colon cancer through the mechanism of exosome-mediated miRNAs transfer. However, the exosomal miRNAs regulation mechanism by F. nucleatum in colon cancer is not well known. Thus, we performed next-generation sequencing to investigate the overall pattern of exosomal miRNAs expression in the colon cancer cell culture supernatant. We have confirmed the alterations of various exosomal miRNAs. In addition, to investigate the function of exosomal miRNAs, a Kyoto Encyclopedia of Genes and Genomes analysis was performed on the target genes of changed miRNAs. Potential target genes were associated with a variety of signaling pathways, and one of these pathways was related to colorectal cancer. These findings suggested that F. nucleatum can alter exosomal miRNAs released from colorectal cancer cells. Furthermore, exosomal miRNAs altered by F. nucleatum could be potential biomarkers for the diagnosis and therapy of colon cancer.

• 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.