• Asian Pacific Journal of Cancer Prevention
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• 제15권14호
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• pp.5583-5586
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• 2014

Helicobacter pylori (H. pylori) infection induces apoptosis in gastric epithelial cells, and this occurrence may link to gastric carcinogenesis. However, the regulatory mechanism of H. pylori-induced apoptosis is not clear. MicroRNA-146a has been implicated as a key regulator of the immune system. This report describes our discovery of molecular mechanisms of microRNA-146a regulation of apoptosis in human gastric cancer cells. We found that overexpression of microRNA-146a by transfecting microRNA-146a mimics could significantly enhance apoptosis, and this upregulation was triggered by COX-2 inhibition. Furthermore, we found that microRNA-146a density was positively correlated with apoptosis rates in H. pylori-positive gastric cancer tissues and intratumoral microRNA-146a density was negatively correlated with lymph node metastasis among H. pylori-positive gastric cancer patients. Understanding the important roles of microRNA-146a in regulating cell apoptosis in H. pylori infected human gastric cancer cells will contribute to the development of microRNA targeted therapy in the future.

• 대한임상검사과학회지
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• 제47권4호
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• pp.292-297
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• 2015

우리나라의 경우 갑상선암, 간암, 폐암 관련 연구가 보고되었으나 다발성 골수종환자에 관한 microRNA 연구는 보고된 경우가 없어 알아보고자 하였다. 또한, 다발성 골수종 환자의 골수(bone marrow)에서 채취한 검체를 이용한 연구가 대부분 보고되고 있으며, 파라핀 포매 조직을 이용한 경우는 거의 없어 파라핀 포매 조직에서도 가능한지 알아보았다. 연구 대상은 2010년 1월부터 2012년 7월까지 충남대학교병원 진단검사의학과에 다발성 골수종 진단을 위해 골수검사를 의뢰한 8 검체를 대상으로 하였다. microRNA는 보고된 내용 중 관련성이 높다고 한 miR-15a와 miR-16, miR-21, miR-181a, miR-221를 시행하여 다음과 같은 결과를 얻었다. 각 검체별 fold change 값이 1.5 이상 또는 -1.5 이하로 유의성을 보인 경우는 miR-15a에서 3예(37.5%)로 나타났다. Microarray 검사법으로 보고한 기존 연구와 비교한 결과, miR-15a의 경우 일치하는 결과로 한국인의 다발성 골수종 환자에서 진단에 활용할 수 있음을 확인하였다. miR-221은 상반된 결과를 얻었다. 이와 같이 miR-15a의 경우, 서양인과 일치하는 결과를 얻었으며, miR-221은 서양인과 상반된 결과로 좀 더 연구가 필요하리라 생각된다. 파라핀 포매 조직에서도 microRNA를 검출 할 수 있음을 확인하였다. 하지만 검체수가 적어 좀 더 정확한 확인 검사와 많은 검체를 이용한 연구가 더욱 필요하다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권8호
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• pp.3687-3690
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• 2014

MicroRNA 200c is a microRNA 200 family member that plays an important role in regulation of the epithelial-to-mesenchymal transition (EMT). The prognostic value of microRNA 200c in solid tumors remains controversial because of inconsistent data. Here, we report a meta-analysis of the association of microRNA 200c expression and survival in patients with solid tumors. Pubmed was searched up to November 2013 for studies investigating microRNA 200c expression and overall survival (OS) in solid tumors. Hazard ratios (HRs) with 95% confidence intervals (CIs) for OS were extracted from each study. Pooled HR and CIs were calculated using the Mantel-Haenszel fixed-effects models. A total of five studies evaluating colorectal cancer, gastric cancer, ovarian cancer, pancreatic cancer and endometrial cancer were included in the analysis. Data were divided into tissue microRNA 200c expression group and serum microRNA 200c expression group. The combined HRs [95%CIs] estimated for OS were 0.62 [0.42-0.91] and 2.16 [1.32-3.52] respectively. Low expression of microRNA 200c in tumor tissue and high expression of microRNA 200c in serum are associated with worse survival in solid tumors. Further study is needed to elucidate this contradiction.

• Asian Pacific Journal of Cancer Prevention
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• 제15권8호
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• pp.3471-3476
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• 2014

Background: Aberrant expression of the microRNA-29 family is associated with tumorigenesis and cancer progression. As transport carriers, tumor-derived exosomes are released into the extracellular space and regulate multiple functions of target cells. Thus, we assessed the possibility that exosomes could transport microRNA-29c as a carrier and correlations between microRNA-29c and apoptosis of bladder cancer cells. Materials and Methods: A total of 28 cancer and adjacent tissues were examined by immunohistochemistry to detect BCL-2 and MCL-1 expression. Disease was Ta-T1 in 12 patients, T2-T4 in 16, grade 1 in 8, 2 in 8 and 3 in 12. The expression of microRNA-29c in cancer tissues was detected by quantitative reverse transcriptase PCR (QRT-PCR). An adenovirus containing microRNA-29c was used to infect the BIU-87 human bladder cancer cell line. MicroRNA-29c in exosomes was measured by QRT-PCR. After BIU-87 cells were induced by exosomes-derived microRNA-29c, QRT-PCR was used to detect the level of microRNA-29c. Apoptosis was examined by flow cytometry and BCL-2 and MCL-1 mRNA expressions were assessed by reverse transcription-polymerase chain reaction. Western blotting was used to determine the protein expression of BCL-2 and MCL-1. Results: The expressions of BCL-2 and MCL-1 protein were remarkably increased in bladder carcinoma (p<0.05), but was found mainly in the basal and suprabasal layers in adjacent tissues. The expression of microRNA-29c in cancer tissues was negatively correlated with the BCL-2 and MCL-1. The expression level of microRNA-29c in exosomes and BIU-87 cells from the experiment group was higher than that in control groups (p<0.05). Exosome-derived microRNA-29c induced apoptosis (p<0.01). Although only BCL-2 was reduced at the mRNA level, both BCL-2 and MCL-1 were reduced at the protein level. Conclusions: Human bladder cancer cells infected by microRNA-29c adenovirus can transport microRNA-29c via exosomes. Moreover, exosome-derived microRNA29c induces apoptosis in bladder cancer cells by down-regulating BCL-2 and MCL-1.

• 대한임상검사과학회지
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• 제50권2호
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• pp.197-204
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• 2018

다발성 골수종(MM)은 혈액 종양의 주요 사망 원인이다. 최근에 다발성 골수종 진단에 microRNA를 이용한 실험이 보고되고 있다. 이에 우리는 다발성 골수종 진단 마커로 miR-221을 이용 할 수 있는지 확인하고자 하였다. 본 연구는 다른 혈액학적 질환이 없는 다발성 골수종 환자 20명을 대상으로 하였다. MicroRNA 추출은 다발성 골수종 환자의 파라핀 포매 조직을 이용하였다. 우리는 다발성 골수종의 microRNA 표적 유전자로 miR-15a, miR-16, miR-21, miR-181a 그리고 miR-221을 선택하였다. 유의성 검정은 fold change 값을 기준으로 1.5이상 또는 -1.5 미만의 결과를 유의성이 있는 경우로 하였다. Fold change 값은 인간 유전자 SNORD43에 의해 표준화된 데이터를 기준으로 하였다. Fold change 값이 1.5 이상은 "overexpression", -1.5 미만의 값은 "underexpression"으로 정의되었다. miR-221의 65.0% (13/20)에서 "overexpression"으로 유의성이 있음을 확인하였고, 다발성 골수종 환자에서 형질세포가 30% 이상인 그룹과 이하의 그룹은 유의성을 보이지 않았다. MiR-221은 서구인과 같은 결과를 얻었으며, 다발성 골수종 환자에서 miR-221이 다발성 골수종 환자 진단에 매우 중요한 지표가 될 수 있을 것으로 생각된다. 결론적으로 miR-221은 한국인의 다발성 골수종 진단 또는 예후 지표로 활용할 수 있음을 확인하였다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권21호
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• pp.9059-9064
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• 2014

MicroRNAs (miRNAs) are ubiquitously expressed small, non-coding RNAs that negatively regulate gene expression at a post transcriptional/translational level. They have emerging as playing crucial roles in cancer at all stages ranging from initiation to metastasis. As a tumor suppressor miRNA, aberrant expression of microRNA-29b (miR-29b) has been detected in various types of cancer, and its disturbance is related with tumor development and progression. In this review, we summarize the latest findings with regard to the tumor suppressor signatureof miR-29b and its regulatory mechanisms. Our review highlights the diverse relationships between miR-29b and its target genes in malignant tumors.

• Asian Pacific Journal of Cancer Prevention
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• 제15권20호
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• pp.8595-8601
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• 2014

Background: miR-200a expression is frequently altered in numerous cancers. The aim of the present study was to determine the role of microRNA-200a in advanced ovarian carcinomas. Materials and Methods: We measured miR-200a expression in 72 matched normal ovarian tissues and advanced ovarian carcinomas, and also two ovarian carcinoma cell lines (SKOV3 and SKOV3.ip1 - the latter being more invasive and metastatic than the parental SKOV3) by stem-loop real-time RT-PCR based on TaqMan microRNA assay using U6 as a reference. Levels of miR-200a expression were compared by disease stage, tumor grade, histology, and lymph node involvement. To evaluate the role of microRNA-200a, cell proliferation and invasion of SKOV-3 and SKOV-3.ip1 were analyzed with miR-200a inhibitor/mimic transfected cells. Results: Of 72 paired samples, 65 cancer tissues overexpressed microRNA-200a greater than two fold in comparison with matched normal epithelium. Specifically, patients with lymph node metastasis showed significant elevation. The level correlated with clinicopathological features, including high tumor grade, late disease stage, most notably with lymph node metastasis, but not with tumor histology. In addition, SKOV-3.ip1 cells also overexpressed miR-200a compared with SKOV-3, and miR-200a inhibitor transfected SKOV-3.ip1 cells showed significant reduction in cellular proliferation and invasion, while a miR-200a mimic stimulated the opposite behavior. Conclusions: We provide definitive evidence that miR-200a is up-regulated in a significant proportion of advanced ovarian carcinomas, and that elevated miR-200a expression facilitates tumor progression. Our findings support the notion that miR-200a is an onco-microRNA for ovarian cancer, and elevation is a useful potential diagnostic indicator. This study also provides a solid basis for further functional analysis of miR-200a in advanced ovarian cancer.

• Molecules and Cells
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• 제39권5호
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• pp.375-381
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• 2016

MicroRNAs (miRNAs) are small non-coding RNAs (~22 nucleotides) regulating gene expression at the post-transcriptional level. By directing the RNA-induced silencing complex (RISC) to bind specific target mRNAs, miRNA can repress target genes and affect various biological phenotypes. Functional miRNA target recognition is known to majorly attribute specificity to consecutive pairing with seed region (position 2-8) of miRNA. Recent advances in a transcriptome-wide method of mapping miRNA binding sites (Ago HITS-CLIP) elucidated that a large portion of miRNA-target interactions in vivo are mediated not only through the canonical "seed sites" but also via non-canonical sites (~15-80%), setting the stage to expand and determine their properties. Here we focus on recent findings from transcriptome-wide non-canonical miRNA-target interactions, specifically regarding "nucleation bulges" and "seed-like motifs". We also discuss insights from Ago HITS-CLIP data alongside structural and biochemical studies, which highlight putative mechanisms of miRNA target recognition, and the biological significance of these non-canonical sites mediating marginal repression.

• BMB Reports
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• 제46권11호
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• pp.550-554
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• 2013

The platelet-derived growth factor (PDGF) signaling pathway is essential for inducing a dedifferentiated state of vascular smooth muscle cells (VSMCs). Activation of PDGF inhibits smooth muscle cell (SMC)-specific gene expression and increases the rate of proliferation and migration, leading to dedifferentiation of VSMCs. Recently, microRNAs have been shown to play a critical role in the modulation of the VSMC phenotype in response to extracellular signals. However, little is known about microRNAs regulated by PDGF in VSMCs. Herein, we identify microRNA- 15b (miR-15b) as a mediator of VSMC phenotype regulation upon PDGF signaling. We demonstrate that miR-15b is induced by PDGF in pulmonary artery smooth muscle cells and is critical for PDGF-mediated repression of SMC-specific genes. In addition, we show that miR-15b promotes cell proliferation. These results indicate that PDGF signaling regulates SMC-specific gene expression and cell proliferation by modulating the expression of miR-15b to induce a dedifferentiated state in the VSMCs.

• 생명과학회지
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• 제15권6호
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• pp.909-915
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• 2005

우리는 바이러스로는 최초로 miRNA를 생성한다고 보고된 Epstein-Barr virus (EBV)를 대상으로 EBV miRNA biogenesis를 연구했다. 먼저 EVB에 감염된 B 세포인 B95-8로부터 보고된 5 종의 EBV miRNA들인 BHRF1-1, BHRF1-2, BHRF1-3, BART1, 및 BART2 모두가 발현됨을 확인하였다. 그 다음 성숙된 EBV miRNA 서열로부터 예측되는 pri- 와 pre-miRNA들이 B95-8에서 각각 검출되어 EBV miRNA들도 이미 알려진 동물세포 miRNA와 유사한 생성 및 성숙과정을 거칠 가능성을 확인하였다 게놈 상에 2~7개씩 밀집하여 존재하는 동물세포 miRNA들과 유사하게 EBV 게놈의 2부 위에 밀집해서 존재하는 EBV miRNA들도 polycistronic하게 발현되는지 조사한 결과 B95-8에서 BHRF1-1, BHRF1-2 및 BHRF1-3를 포함하는 1,602 뉴클레오타이드의 긴 전사체가 RT-PCR로 확인되었다. 반면 BART1과 BART2는 mono cistronic하게 전사될 가능성이 확인되었다. 본 연구를 통하여 EBV miRNA들도 동물세포 miRNA들과 유사하게 poly cistronic 하게 발현될 수 있으며 pri-와 pre-miRNA 과정을 거쳐 성숙된 miRNA로 생성될 가능성을 확인하였다.