• 대한의생명과학회지
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• 제21권1호
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• pp.1-8
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• 2015

Alzheimer's disease is a common form of dementia occurring among the elderly population and can be identified by symptoms such as cognition impairments, memory loss and neuronal dysfunction. Alzheimer's disease was found to be caused by the deposition of $\beta$-amyloid plaques and neurofibrillary tangles. In addition, mutation in the APP (Amyloid precursor protein), Presenilin 1 (PSEN1) and Presenilin 2 (PSEN2) genes were also found to contribute to Alzheimer's disease. Since the potential conformational diagnosis of Alzheimer's disease requires histopathological tests on brain through autopsy, potential early diagnosis still remains challenging. In recent years, several researches have proposed the use of biomarkers for early diagnosis. In cerebrospinal fluid (CSF), $\beta$-amyloid(1-42), phosphorylated-tau and total tau were suggested to be effective biomarkers for Alzheimer's disease diagnosis. However, a single biomarker might not be sufficient for potential diagnosis of Alzheimer's disease. Thus, the use of RNA interference (RNAi) through microRNAs (miRNAs) has been proposed by several researchers for simultaneous analysis of several biomarkers using microarray technology. These miRNA based biomarkers can be analysed from both blood and CSF, but miRNAs from blood are advantageous over CSF as they are non-invasive and simple for collection. Moreover, the RNAi based therapeutics by siRNA (short interference RNA) or shRNA (short hairpin RNA) have also been proposed to be effective in the treatment of Alzheimer's disease. This review describes the promising application of RNAi technology in therapeutics and as a biomarker for both Alzheimer's disease diagnosis and treatment.

• 한국유전체학회:학술대회논문집
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• 한국유전체학회 2003년도 The 12th Korea Genome Conference
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• pp.54.1-54.1
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• 2003

• Genomics & Informatics
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• 제18권4호
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• pp.36.1-36.9
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• 2020

Since lung cancer is a major causative for cancer-related deaths, the investigations for discovering biomarkers to diagnose at an early stage and to apply therapeutic strategies have been continuously conducted. Recently, long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) are being exponentially studied as promising biomarkers of lung cancer. Moreover, supportive evidence provides the competing endogenous RNA (ceRNA) network between lncRNAs and miRNAs participating in lung tumorigenesis. This review introduced the oncogenic or tumor-suppressive roles of lncRNAs and miRNAs in lung cancer cells and summarized the involvement of the lncRNA/miRNA ceRNA networks in carcinogenesis and therapeutic resistance of lung cancer.

• Journal of Nutrition and Health
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• 제55권1호
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• pp.36-46
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• 2022

Quercetin의 지질대사 개선 효과에 대한 작용기전을 확인하기 위해 C57BL/6J mouse를 사용하여 실험을 수행하였다. 고콜레스테롤혈증을 유도하기 위해 6주간 1% 콜레스테롤과 0.5% cholic acid를 함유하는 고콜레스테롤 식이를 급여하였으며, quercetin은 0.05%와 0.1%의 수준으로 고콜레스테롤 식이에 추가하여 같은 기간 동안 제공하였다. Quercetin은 혈청과 간의 중성지방 및 콜레스테롤 수준을 용량 의존적으로 감소하는 것으로 나타났다. 고콜레스테롤 식이를 섭취한 쥐의 간에서 지방 합성을 촉진하는 SREBP-1c, ACC1 및 FAS 유전자 발현이 quercetin 섭취에 의해 억제되는 것을 확인하였다. Quercetin은 간세포 내에서 에너지 대사를 조절하는 AMPK 활성을 증가시켰다. 이에 반해 암세포 증식을 촉진하고 지방간에서 높게 발현되는 miR-21 발현은 quercetin 섭취에 의해 감소되었다. 본 연구의 결과는 quercetin이 고콜레스테롤 식이 섭취 쥐에서 혈청과 간의 지질 수준을 낮추는 지질대사 개선 효과가 있으며, 이러한 효과의 일부는 간 내 지방합성 유전자 (SREBP-1c, ACC1 및 FAS) 발현, AMPK 활성 및 miR-21 조절을 통해 매개된다는 것을 시사한다.

• Reproductive and Developmental Biology
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• 제32권4호
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• pp.229-235
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• 2008

Silencing of Dicer1 by siRNA did not inhibit development up to the blastocyst stage, but decreased expression of selected transcription factors, including Oct-4, Sox2 and Nanog, suggesting that Dicer1 gene expression is associated with differentiation processes at the blastocyst stage (Cui et al., 2007). In order to get insights into genes which may be linked with microRNA system, we compared gene expression profiles in Gapdh and Dicer1 siRNA-microinjected blastocysts using the Applied Biosystem microarray technology. Our data showed that 397 and 737 out of 16354 genes were up- and down-regulated, respectively, following siRNA microinjection (p<0.05), including 24 up- and 28 down-regulated transcription factors. Identification of genes that are preferentially expressed at particular Dicer1 knock down embryos provides insights into the complex gene regulatory networks that drive differentiation processes in embryos at blastocyst stage.

• Journal of Nutrition and Health
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• 제54권5호
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• pp.448-458
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• 2021

본 연구는 뽕나무 열매 착즙 분말 (MJ)이 지방세포 분화과정에서 염증에 관여하는 유전자 발현 및 miR-132/143 조절에 미치는 효과에 중점을 두고 조사하였다. MJ는 3T3-L1 지방세포 분화 동안 지질축적이 억제되었고 PPAR-γ, CEBP-α 및 aP2와 같은 지방형성 유전자 발현을 억제하였다. 또한 염증 조절 매개체인 TNF-α, IL-6, MCP-1 및 iNOS 유전자 발현이 MJ 처리에 의해 감소되었다. MJ의 지질 축적 억제 효과는 염증과 지방분화에 관여하는 miR-132/143의 발현 감소와 관련이 있음을 확인하였다. 따라서 MJ는 염증을 동반하는 비만 예방 및 치료에 도움이 될 수 있는 식품 소재로서 가능성이 있음을 시사하고 있다. 그러나 MJ의 주요 성분인 안토시아닌의 생체이용율은 1-2% 미만으로 추정되며 예상되는 표적 조직이나 혈류에서 미량 검출되는 것으로 알려져 있다 [33]. 이를 해결하기 위해서는 생체 내 동물실험을 통한 다각적인 분석이 향후 진행되어야 할 것으로 판단된다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권8호
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• pp.3363-3368
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• 2014

Background: Curcumin, a phenolic compound extracted from the rhizomes of Curcuma longa, has shown cytotoxic effects against a variety of cancers. The aim of this study was to identify potential microRNA (miRNA) mediators of the anticancer effects of curcumin in ovarian cancer cells. Materials and Methods: SKOV3 ovarian cancer cells were treated with curcumin ($10-60{\mu}M$) and miR-9 expression, cell proliferation, and apoptosis were assessed. The effects of miR-9 depletion on curcumin-mediated growth suppression were also examined. Phosphorylation of Akt and forkhead box protein O1 (FOXO1) was measured in cells with miR-9 overexpression or curcumin treatment. Results: Curcumin caused a significant and dose-dependent increase of miR-9 expression in SKOV3 cells, while significantly impeding cell proliferation and stimulating apoptosis. Depletion of miR-9 significantly (p<0.05) attenuated the growth-suppressive effects of curcumin on SKOV3 cells, coupled with reduced percentages of apoptotic cells. In contrast, overexpression of miR-9 significantly enhanced the cleavage of caspase-3 and poly(ADP-ribose) polymerase and promoted apoptotic death in SKOV3 cells. Western blot analysis showed that both miR-9 overexpression and curcumin similarly caused a significant (p<0.05) decline in the phosphorylation of Akt and FOXO1, compared to untreated cells. Conclusions: The present study provided evidence that curcumin exerts its cytotoxic effects against SKOV3 ovarian cancer cells largely through upregulation of miR-9 and subsequent modulation of Akt/FOXO1 axis. Further studies are needed to identify direct targets of miR-9 that mediate the anticancer effects of curcumin in ovarian cancer cells.

• Journal of Cancer Prevention
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• 제22권1호
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• pp.33-39
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• 2017

Background: MicroRNAs (miRNAs) are key post-translational mechanisms which can regulate gene expression in gastric carcinogenesis. To identify miRNAs responsible for gastric carcinogenesis, we compared expression levels of miRNAs between gastric cancer tissue and non-cancerous gastric mucosa according to Helicobacter pylori status. Methods: Total RNA was extracted from the cancerous regions of formalin-fixed, paraffin-embedded tissues of H. pylori-positive (n = 8) or H. pylori-negative (n = 8) patients with an intestinal type of gastric cancer. RNA expression was analyzed using a 3,523 miRNA profiling microarray based on the Sanger miRBase. Validation analysis was performed using TaqMan miRNA assays for biopsy samples from 107 patients consisted of control and gastric cancer with or without H. pylori. And then, expression levels of miRNAs were compared according to subgroups. Results: A total of 156 miRNAs in the aberrant miRNA profiles across the miRNA microarray showed differential expression (at least a 2-fold change, P < 0.05) in cancer tissue, compared to noncancerous mucosa in both of H. pylori-negative and -positive samples. After 10 promising miRNAs were selected, validations by TaqMan miRNA assays confirmed that two miRNAs (hsa-miR-135b-5p and hsa-miR-196a-5p) were significantly increased and one miRNA (hsa-miR-145-5p) decreased in cancer tissue compared to non-cancerous gastric mucosa at H. pylori-negative group. For H. pylori-positive group, three miRNAs (hsa-miR-18a-5p, hsa-miR-135b-5p, and hsa-miR-196a-5p) were increased in cancer tissue. hsa-miR-135b-5p and hsa-miR-196a-5p were increased in gastric cancer in both of H. pylori-negative and -positive. Conclusions: miRNA expression of the gastric cancer implies that different but partially common gastric cancer carcinogenic mechanisms might exist according to H. pylori status.

• Genomics & Informatics
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• 제12권4호
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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.

• Asian Pacific Journal of Cancer Prevention
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• 제15권13호
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• pp.5137-5142
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• 2014

Adriamycin (ADR) is an important chemotherapeutic agent frequently used in treatment of breast cancer. However, resistance to ADR results in treatment failure in many patients. Recent studies have indicated that microRNAs (miRNAs) may play an important role in such drug-resistance. In the present study, microRNA-452 (miR-452) was found to be significantly down-regulated in adriamycin-resistant MCF-7 cells (MCF-7/ADR) compared with the parental MCF-7 cells by miRNA microarray and real-time quantitative PCR (RT-qPCR). MiR-452 mimics and inhibitors partially changed the adriamycin-resistance of breast cancer cells, as also confirmed by apoptosis assay. In exploring the potential mechanisms of miR-452 in the adriamycin-resistance of breast cancer cells, bioinformatics analysis, RT-qPCR and Western blotting showed that dysregulation of miR-452 played an important role in the acquired adriamycin-resistance of breast cancer, maybe at least in part via targeting insulin-like growth factor-1 receptor (IGF-1R).