• 한국어병학회지
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• 제33권1호
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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.

• 대한상부위장관⦁헬리코박터학회지
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• 제18권3호
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• pp.168-173
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• 2018

Gastric cancer is still the leading cause of cancer deaths, especially in Asian countries. Recently, many studies have analyzed cell-free nucleic acids (cfNAs) circulating in the blood, for the early diagnosis of cancer and monitoring its progression. Circulating tumor nucleic acids (ctNAs) originate in a tumor and contain tumor-related genetic or epigenetic alterations. This review defines the nomenclatures of each form of cfNAs and describes the characteristics of circulating tumor DNA (ctDNA) and microRNA (miRNA), two major forms of ctNAs studied in gastric cancer research to date. We compare available studies on ctDNA, and explain trends observed in studies of miRNAs in gastric cancers. As these new blood-based biomarkers have attracted increasing attention, we have discussed several important points to be considered before the clinical translation of ctNA detection. We have also discussed the current status of research in this field, and clinical applications of specific ctNAs as tumor markers for gastric cancer diagnosis.

• Nutrition Research and Practice
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• 제14권4호
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• pp.412-422
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• 2020

BACKGROUND/OBJECTIVES: This study investigates correlations between circulating microRNAs (miRNAs) and obesity-related parameters among young women (aged 20-30 years old) in Korea. SUBJECTS/METHODS: We analyzed TaqMan low density arrays (TLDAs) of circulating miRNAs in 9 lean (body mass index [BMI] < 25 kg/㎡) and 15 obese (BMI > 25 kg/㎡) women. We also performed gene ontology (GO) analyses of the biological functions of predicted miRNA target genes, and clustered the results using the database for annotation, visualization and integrated discovery. RESULTS: The TLDA cards contain 754 human miRNAs; of these, the levels of 8 circulating miRNAs significantly declined (> 2-fold) in obese subjects compared with those in lean subjects, including miR-1227, miR-144-5p, miR-192, miR-320, miR-320b, miR-484, miR-324-3p, and miR-378. Among them, miR-484 and miR-378 displayed the most significant inverse correlations with BMI (miR-484, r = -0.5484, P = 0.0056; miR-378, r = -0.5538, P = 0.0050) and visceral fat content (miR-484, r = -0.6141, P = 0.0014; miR-378, r = -0.6090, P = 0.0017). GO analysis indicated that genes targeted by miR-484 and miR-378 had major roles in carbohydrate and lipid metabolism. CONCLUSION: Our result showed the differentially expressed circulating miRNAs in obese subjects compared to lean subjects. Although the mechanistic study to reveal the causal role of miRNAs remains, these miRNAs may be novel biomarkers for obesity.

• Asian Pacific Journal of Cancer Prevention
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• 제14권4호
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• pp.2167-2172
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• 2013

Lung cancer remains a major cause of morbidity and mortality worldwide, accounting for more deaths than any other cause. All the clinical practice guidelines recommended against routine screening for lung cancer have cited lack of robust evidence, at least until a few years back. However, the potential to screen lung cancers has received renewed interest due to superior performance of low dose CT (LD-CT) in detecting early stage cancers. The incremental costs and risks involved due to the invasive procedures in the screened population due to a high false positivity rate questions the use of LD-CT scan as a reliable community based screening tool. There is therefore an urgent need to find a less invasive and a more reliable biomarker that is crucial to increase the probability of early lung cancer detection. This can truly make a difference in lung cancer survival and at the same time be more cost and resource utilization effective. Sampling blood serum being minimally invasive, low risk and providing an easy to obtain biofluid, needs to be explored for potential biomarkers. This review discusses the use of circulatory miRNAs that have been able to discriminate lung cancer patients from disease free controls. Several studies conducted recently suggest that circulating miRNAs may have promising future applications for screening and early detection of lung cancer.

• Asian Pacific Journal of Cancer Prevention
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• 제17권9호
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• pp.4241-4246
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• 2016

Background: Dysregulation of miRNA expression may be used as a biomarker for specific tumours because it may contribute to development of cancer. Circulating miRNA profiles have been highlighted for their potential as predictive markers in heterogeneous diseases such as breast cancer. In the literature, there is evidence that miR-195 levels are differentially expressed pre- and post-operative periods in breast cancer patients. At the same time, miRNA expression levels may vary because of ethnic origins. This study aimed to determine expression levels and potential roles of miR-195 in Turkish breast cancer patients. Materials and Methods: The expression patterns of miR-195 were initially examined in breast cancer tissues (luminal A and B type) (n=96). Subsequently, blood samples were prospectively collected from preoperative and postoperative Turkish breast cancer patients and disease free controls. Total RNA was isolated, and the expression level of miR-195 was quantified by real-time PCR. Results: We found that miR-195 level was altered in Turkish breast cancer patients, with down-regulation evident in breast cancer tissues compared to normal adjacent specimens. Furthermore, circulating levels of miR-195 was significantly decreased in post-operative blood samples compared with pre-operative levels (p=0.01 and <0.05). However, miR-195 was significantly increased in pre-operative blood samples of the luminal B type (p=0.04 and <0.05). Conclusions: This study represents the first report of a miR-195 expression profile in Turkish breast cancer patients. Our data suggests that miR-195 levels might be a clinically useful biomarker in the earliest stage of Turkish breast cancer patients.

• Tuberculosis and Respiratory Diseases
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• 제77권2호
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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.

• 한국어병학회지
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• 제29권1호
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• pp.25-33
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• 2016

In human medicine, circulating microRNAs have been successfully utilized as early biomarkers for various abnormalities and disease states. Vertebrate miR-122 is a liver-specific microRNA which is expressed almost solely in hepatocytes and plays an important role in the regulation of hepatocyte function. In this study, to evaluate the potential utility of circulating miR-122 as a biomarker for liver injury in olive flounder (Paralichthys olivaceus), fish were orally intubated with two doses of acetaminophen (500 mg/kg or 1.000 mg/kg of body weight), and the expression of miR-122 in serum was quantified using real time-PCR. Histological change in liver, and the enzymatic activity of glutamic oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT) were also analyzed. The results showed that miR-122 was higher in acetaminophen administered groups compared to control group. The histopathological effect of acetaminophen on olive flounder liver was not distinct. The serum level of GPT and GOT was increased within 2 folds compared to control group by acetaminophen administration. However, the serum miR-122 level was increased more than 3 or 4 folds compared to the control group by administration of 1000 mg/kg of acetaminophen. These results suggest the possible use of miR-122 as an indicator of liver injury in olive flounder, even when histopathological effects are not distinctive.

• 한국동물생명공학회지
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• 제36권1호
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• pp.35-44
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• 2021

A pregnancy diagnosis is an important standard for control of livestock's reproduction in paricular dairy cattle. High reproductive performance in dairy animals is a essential condition to realize of high life-time production. Pregnancy diagnosis is crucial to shortening the calving interval by enabling the farmer to identify open animals so as to treat or re-breed them at the earliest opportunity. MicroRNAs are short RNA molecules which are critically involved in regulating gene expression during both health and disease. This study is sought to establish the feasible of circulating miRNAs as biomarkers of early pregnancy in cattle. We applied Illumina small-RNA sequencing to profile miRNAs in plasma samples collected from 12 non-pregnant cows ("open" cows: samples were collected before insemination (non-pregnant state) and after pregnancy check at the indicated time points) on weeks 0, 4, 8, 12 and 16. Using small RNA sequencing we identified a total of 115 miRNAs that were differentially expressed weeks 16 relative to non-pregnancy ("open" cows). Weeks 8, 12 and 16 of pregnancy commonly showed a distinct increase in circulating levels of miR-221 and miR-320a. Through genome-wide analyses we have successfully profiled plasma miRNA populations associated with pregnancy in cattle. Their application in the field of reproductive biology has opened up opportunities for research communities to look for pregnancy biomarker molecules in dairy cattle.

• Journal of Digestive Cancer Research
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• 제8권1호
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• pp.56-60
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• 2020

In recent years, liquid biopsy has received immense attention. Liquid biopsy is a minimally invasive method used for obtaining biological fluids including urine, pleural fluid and, mostly, peripheral blood. Liquid biopsy involves various targets including circulating tumors cells (CTCs), circulating cell-free tumor DNA (ctDNA), and microRNA (miRNA). Colorectal cancer (CRC), like other solid tumors, shed tumor cells into the bloodstream. Analysis of these CTCs, as well as ctDNA is the primary objective of the liquid biopsy. Evaluation of CTC or ctDNA offers information about early tumor release, development of tumor metastasis and also about mechanisms involved in tumor resistance to treatment.

• IMMUNE NETWORK
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• 제11권1호
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• pp.11-41
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• 2011

The discovery of microRNA (miRNA) is one of the major scientific breakthroughs in recent years and has revolutionized current cell biology and medical science. miRNAs are small (19~25nt) noncoding RNA molecules that post-transcriptionally regulate gene expression by targeting the 3' untranslated region (3'UTR) of specific messenger RNAs (mRNAs) for degradation of translation repression. Genetic ablation of the miRNA machinery, as well as loss or degradation of certain individual miRNAs, severely compromises immune development and response, and can lead to immune disorders. Several sophisticated regulatory mechanisms are used to maintain immune homeostasis. Regulatory T (Treg) cells are essential for maintaining peripheral tolerance, preventing autoimmune diseases and limiting chronic inflammatory diseases. Recent publications have provided compelling evidence that miRNAs are highly expressed in Treg cells, that the expression of Foxp3 is controlled by miRNAs and that a range of miRNAs are involved in the regulation of immunity. A large number of studies have reported links between alterations of miRNA homeostasis and pathological conditions such as cancer, cardiovascular disease and diabetes, as well as psychiatric and neurological diseases. Although it is still unclear how miRNA controls Treg cell development and function, recent studies certainly indicate that this topic will be the subject of further research. The specific circulating miRNA species may also be useful for the diagnosis, classification, prognosis of diseases and prediction of the therapeutic response. An explosive literature has focussed on the role of miRNA. In this review, I briefly summarize the current studies about the role of miRNAs in Treg cells and in the regulation of the innate and adaptive immune response. I also review the explosive current studies about clinical application of miRNA.