• BMB Reports
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• v.42 no.8
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• pp.493-499
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• 2009

MicroRNAs (miRs) are a family of small noncoding RNAs that regulate gene expression by targeting mRNAs in a sequence specific manner, inducing translational repression or mRNA degradation. In this paper we have first analyzed by microarray the miR-profile in erythroid precursor cells from one normal and two thalassemic patients expressing different levels of fetal hemoglobin (one of them displaying HPFH phenotype). The microarray data were confirmed by RT-PCR analysis, and allowed us to identify miR-210 as an highly expressed miR in the erythroid precursor cells from the HPFH patient. When RT-PCR was performed on mithramycin-induced K562 cells and erythroid precursor cells, miR-210 was found to be induced in time-dependent and dose-dependent fashion, together with increased expression of the fetal $\gamma$-globin genes. Altogether, the data suggest that miR-210 might be involved in increased expression of $\gamma$-globin genes in differentiating erythroid cells.

• Journal of fish pathology
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• v.33 no.1
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• pp.35-43
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• 2020

Hypoxia is a serious problem in the marine ecosystem causing a decline in aquatic resources. MicroRNAs (miRNAs) regulate the expression of genes through binding to the corresponding sequences of their target mRNAs. Especially, miRNAs in the cytoplasm can be secreted into body fluids, which called circulating miRNAs, and the availability of circulating miRNAs as biomarkers for hypoxia has been demonstrated in mammals. However, there has been no report on the hypoxia-mediated changes in the circulating miRNAs in fish. miR-210 is known as the representative hypoxia-responsive circulating miRNA in mammals. To know whether fish miR-210 also respond to hypoxia, we analyzed the change of circulating miR-210 quantity in the serum of olive flounder (Paralichthys olivaceus) in response to hypoxia. The expression of hypoxia related genes, hypoxia inducible factor 1α (HIF-1α) and the heat shock protein 90α (HSP90α) was also analyzed. Similar to the reports from mammals, miR-210-5p and miR-210-3p were significantly increased in the serum of olive flounder in response to hypoxia, suggesting that circulating miR-210 levels in the serum can be used as a noninvasive prognostic biomarker for fish suffered hypoxia. The target genes of miR-210 were related to various biological processes, which explains the major regulatory role of miR-210 in response to hypoxia. The expression of HIF-1α and HSP90α in the tissues was also up-regulated by hypoxia. Considering the critical role of HIF-1α in miR-210 expression and HSP90 in miRNAs function, the present up-regulation of HIF-1α and HSP90α might be related to the increase of circulatory miR-210, and the interaction mechanism among HIF-1α, HSP90α, and hypoxia-responsive microRNAs in fish should be further studied.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.6
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• pp.2813-2818
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• 2012

Background: Considerable evidence suggests that metadherin (MTDH) is a potentially crucial mediator of tumor malignancy and an important therapeutic target for simultaneously enhancing chemotherapy efficacy and reducing metastasis risk. Inhibition of MTDH expression by RNA interference has been shown in several previous research, but silencing MTDH expression by microRNA (miRNA) interference in breast cancer has not been established. In the present study, we investigated the role of MTDH-miRNA in down-regulation of proliferation, motility and migration of breast carcinoma cells. Methods: Expression vectors of recombinant plasmids expressing artificial MTDH miRNA were constructed and transfected to knockdown MTDH expression in MDA-MB-231 breast cancer cells. Expression of MTDH mRNA and protein was detected by RT-PCR and Western blot, respectively. MTT assays were conducted to determine proliferation, and wound healing assays and transwell migration experiments for cell motility and migration. Results: Transfection of recombinant a plasmid of pcDNA-MTDH-miR-4 significantly suppressed the MTDH mRNA and protein levels more than 69% in MDA-MB-231 breast cancer cells. This knockdown significantly inhibited proliferation, motility and migration as compared with controls. Conclusions: MTDH-miRNA may play an important role in down-regulating proliferation, motility and migration in breast cancer cells, and should be considered as a potential small molecule inhibitor therapeutic targeting strategy for the future.

• Biomedical Science Letters
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• v.27 no.4
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• pp.216-222
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• 2021

Colorectal cancer (CRC) is major cancer with high incidence and mortality worldwide. It is known that most CRCs arise from precursor adenomatous polyps (APs). Recently, microRNA (miRNA) has been proposed as a biomarker for various cancers including CRC. In this study, the expression patterns of miR-29a in the whole blood (WB) of CRC, AP, and control groups were analyzed by reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR) to evaluate the expression level of miR-29a in patients with colorectal neoplasm (CRN) including CRC and AP. As a result, the relative expression of miR-29a was significantly decreased in the patients with CRN compared to the control group (P<0.001). The results were in agreement with previous in vitro cell studies and studies that used tissue and feces samples, suggesting that miR-29a in WB may be useful in demonstrating the status of colorectal tissue. Additionally, we divided the control group into healthy control (HC) without any colorectal symptoms and non-tumor control (NTC) with colorectal symptoms but without any CRN. And then the relative expression of miR-29a was also significantly decreased in the NTC group compared to the HC group (P<0.001). Therefore, our study revealed that miR-29a can differentiate patients with CRN from HC group, but they are also involved in the early stage of inflammatory response and cannot be specific biomarkers for CRN.

• Journal of Life Science
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• v.26 no.6
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• pp.705-710
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• 2016

Colorectal cancer (CRC) is the third most common cancer and a leading cause of cancer-related death worldwide. Although several diagnostic and therapeutic tools have been available, CRC remains difficult to complete cure because of insufficient understanding of the molecular mechanisms underlying this disease progression. MicroRNAs (miRNAs) are small non-coding RNA molecules that strongly regulate gene expression via transcriptional and translational control mechanisms. Many crucial cellular pathways are frequently disrupted in cancer development process due to dysregulation of several miRNAs. Mir-31 functions as an oncogene that modulate expression of multiple cancer related genes. Thus, we aimed to demonstrate clinical relevance of miR-31 in human CRC. Quantitative RT-PCR analysis of miR-31 expression was performed in 175 CRC tissues and 16 normal colonic mucosa (NM). Next, we investigated clinical significances of miR-31 expression in various clinicopathologic features in CRC patients cohort. Mir-31 was significantly up-regulated in CRC tissues compared to NM. In CRC tissues, miR-31 expression level was significantly elevated in a stage-dependent manner, which was associated with poor survival in patients with CRC. High miR-31 levels in CRC tissues significantly correlated with poor prognosis (hazard ratio [HR]=2.4) as well as distant metastasis (odds ratio [OR]=2.3). In conclusion, we identified clinical significance of miR-31 expression in CRC. High miR-31 expression may be clinically able to use as a biomarker for CRC prognosis and predicting metastasis.

• BMB Reports
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• v.42 no.3
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• pp.131-135
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• 2009

MicroRNAs control gene expression by inhibiting translation or promoting degradation of their target mRNAs. Since the discovery of the first microRNAs, lin-4 and let-7, in C. elegans, hundreds of microRNAs have been identified as key regulators of cell fate determination, lifespan, and cancer in species ranging from plants to humans. However, while microRNAs have been shown to be particularly abundant in the brain, their role in the development and activity of the nervous system is still largely unknown. In this review, we describe recent advances in our understanding of microRNA function at synapses, the specialized structures required for communication between neurons and their targets. We also propose how these advances might inform the molecular model of memory.

• The Korean Journal of Physiology and Pharmacology
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• v.23 no.3
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• pp.171-179
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• 2019

Pituitary tumors are usually benign but can occasionally exhibit hormonal and proliferative behaviors. Dysregulation of the G1/S restriction point largely contributes to the over-proliferation of pituitary tumor cells. F-box protein S-phase kinase-interacting protein-2 (SKP2) reportedly targets and inhibits the expression of $p27^{Kip1}$, a well-known negative regulator of G1 cell cycle progression. In this study, SKP2 expression was found to be upregulated while $p27^{Kip1}$ expression was determined to be downregulated in rat and human pituitary tumor cells. Furthermore, SKP2 knockdown induced upregulation of $p27^{Kip1}$ and cell growth inhibition in rat and human pituitary tumor cells, while SKP2overexpression elicited opposite effects on $p27^{Kip1}$ expression and cell growth. The expression of microRNA-186 (miR-186) was reported to be reduced in pituitary tumors. Online tools predicted SKP2 to be a direct downstream target of miR-186, which was further confirmed by luciferase reporter gene assays. Moreover, miR-186 could modulate the cell proliferation and $p27^{Kip1}$-mediated cell cycle alternation of rat and human pituitary tumor cells through SKP2. As further confirmation of these findings, miR-186 and $p27^{Kip1}$ expression were downregulated, while SKP2 expression was upregulated in human pituitary tumor tissue samples; thus, SKP2 expression negatively correlated with miR-186 and $p27^{Kip1}$ expression. In contrast, miR-186 expression positively associated with $p27^{Kip1}$ expression. Taken together, we discovered a novel mechanism by which miR-186/SKP2 axis modulates pituitary tumor cell proliferation through $p27^{Kip1}$-mediated cell cycle alternation.

• Proceedings of the SCSK Conference
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• 2003.09a
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• pp.85-96
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• 2003

Normal human skin, constantly challenged by environmental micro-organisms, has an innate ability to fight invading microbes through antimicrobial peptides. These peptides, described in both plant and animal kingdoms are able to inactivate a broad spectrum of micro-organisms. Mammalian defensins constitute one of the most common antimicrobial peptide family. Among the three human beta-defensins hBD1, hBD2 and hBD3 produced in epithelia, only hBD2 and hBD3 are inducible and additionally have been described as expressed by differentiated keratinocytes at site of inflammation and infection. The aims of these studies were to define a cell culture model in which the basal production of hBD could be detected and up-regulated in order to enhance skin auto-protection against micro-organisms. A specific Polymerase Chain Reaction method have been developed for hBD2 and hBD3 mRNA detection in non-differentiated monolayer keratinocytes cell culture. We have been able to demonstrate that in vitro, hBD2 and hBD3 expression in normal human keratinocytes could be detected and enhanced by TNF-alpha and IFN-gamma, in hypercalcic culture conditions. This research opened the possibility of the development of cosmetic active compounds, able to induce the expression of skin natural antibiotic peptides responsible about microflora ecology of the skin.

• Convergence Security Journal
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• v.14 no.5
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• pp.17-24
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• 2014

This study proposed LDP (Local Directional Pattern) as a new local micro pattern for facial expression recognition to solve noise sensitive problem of LBP (Local Binary Pattern). The proposed method extracts 8-directional components using $m{\times}m$ mask to solve LBP's problem and choose biggest k components, each chosen component marked with 1 as a bit, otherwise 0. Finally, generates a pattern code with bit sequence as 8-directional components. The result shows better performance of rotation and noise adaptation. Also, a new local facial feature can be developed to present both PFF (permanent Facial Feature) and TFF (Transient Facial Feature) based on the proposed method.

• Tuberculosis and Respiratory Diseases
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• v.67 no.5
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• pp.413-421
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• 2009

Background: MicroRNAs (miRNAs) play an important role in the regulation of cell proliferation, apoptosis, development and differentiation. Several studies have shown that aberrant expression of miRNAs is involved in cancer development and progression by regulating the expression of proto-oncogenes or tumor suppressor genes. In this study, we investigated miRNA expression profiles in Korean patients with non-small cell lung cancer (NSCLC). Methods: We performed miRNA microarray analysis containing 60~65 bp oligonucleotide probes representing human 318 miRNAs and validated the results of the microarray with Northern blot analysis or quantitative RT-PCR. Next, we examined the correlation between miRNA expression and the target gene transcriptional profile using a human whole-genome-expression microarray. Results: We showed that 35 miRNAs were expressed differentially in the NSCLCs and corresponding non-malignant lung tissues. We showed that 35 miRNAs were expressed differentially in the NSCLCs and corresponding nonmalignant lung tissues. Thirteen of the 35 differentially expressed miRNAs were newly identified in the present study. Of the 35 miRNAs, 2 (miR-371 and miR-210) were over-expressed in lung cancers, and 33 miRNAs, including miR-145, were under-expressed in lung cancers. miR-99b expression consistently showed a negative correlation with FGFR3 expression. Conclusion: Albeit a small number of patients were examined, these results suggest that miRNA expression profiles in Korean lung cancers may be somewhat different from the expression profiles reported on lung cancers in Western populations. The findings suggest that miR-99b might be a tumor suppressor through its up-regulation of FGFR3.