• Korean Journal of Clinical Laboratory Science
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• v.47 no.4
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• pp.298-305
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• 2015

Stem cell-like tumor cells are reported to be the main reason for tumor recurrence and metastasis. As one of the new approaches to overcome cancer, studies are emerging to inhibit the expressions of stem cell transcriptional factors (Oct4, Sox2, Klf-4, and Lin28) in cancer cells. MicroRNAs are master genetic regulators that can control development and differentiation of stem cells. In this study using various ovarian tumors (Skov3, Ovcar3, Tov112D, Tov21G, PA-1 and Hsc832(c)T), we examined the expressions of stem cell-related transcription factors, and the biological changes in cell survival and growth by miR-126 that targets stem cell transcriptional factors. We observed that treatment of miR-126 induced the morphological changes and cell suspension in most cells. In addition, miR-126 induced gradual regression of cell division except Skov3 cells, especially significant time-dependent reduction in Tov112D, Tov21G and PA-1. When we examined the expression of stem cell transcriptional factors, Sox2 was shown to be down-regulated after miR-126. Our results demonstrate that miR-126 treatment can provide the reversible environment to regulate cell division and to induce cell death of ovarian tumors, suggesting the molecular biological clues for clinical usage.

• Journal of Life Science
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• v.24 no.3
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• pp.323-328
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• 2014

MicroRNAs comprise a family of small noncoding RNAs that modulate physiological processes, including adipogenesis. MicroRNA-17 (miR-17) promotes adipocyte differentiation and enhances lipid accumulation. The transcriptional regulation of miR-17 during adipogenesis remains unknown. In this study, we investigated whether miR-17 is a target of peroxisome proliferator-activated receptor ${\gamma}$ ($PPAR{\gamma}$), which is a key regulator of adipogenesis. The levels of miR-17 and the expression of $PPAR{\gamma}$ increased after the induction of adipocyte differentiation. Three putative peroxisome proliferator response elements (PPREs) were identified in the miR-17 promoter region. Using chromatin immunoprecipitation and luciferase reporter assays, we observed the interaction of $PPAR{\gamma}$ with the miR-17 promoter. Mutagenesis experiments showed that the -677/-655 region of the miR-17 promoter could function as a PPRE site. These results suggest that $PPAR{\gamma}$ is essential for transcriptional activation of the miR-17 gene, thereby contributing to understanding the molecular mechanism of adipogenesis in adipocytes.

• International Journal of Oral Biology
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• v.36 no.4
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• pp.179-185
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• 2011

MicroRNAs (miRNAs) are small non-coding RNAs that mediate gene expression at the post-transcriptional level by degrading or repressing targeted mRNAs. These molecules are about 21-25 nucleotides in length and exert their effects by binding to partially complementary sites in mRNAs, predominantly in the 3'-untranslated region (3'-UTR). Recent evidence has demonstrated that miRNAs can function as oncogenes or tumor suppressors through the modulation of multiple oncogenic cellular processes in cancer development, including initiation, cell proliferation, apoptosis, invasion and metastasis. In our present study, we examined the expression profile of miRNAs related to oral cancer cell growth inhibition using normal human oral keratinocytes (NHOK) and YD-38 human oral cancer cells. By miRNA microassay analysis, 40 and 31 miRNAs among the 1,769 examined were found to be up- and down-regulated in YD-38 cells compared with NHOK cells, respectively. Using qRT-PCR analysis, the expression levels of miR-30a and miR-1246 were found to be increased in YD-38 cells compared with NHOK cells, whereas miR-203 and miR-125a were observed to be decreased. Importantly, the overexpression of miR-203 and miR-125a significantly inhibited the growth of YD-38 cells. This finding and the microarray data indicate the involvement of specific miRNAs in the development and progression of oral cancer.

• Journal of Veterinary Science
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• v.24 no.5
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• pp.73.1-73.16
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• 2023

Background: Highly pathogenic avian influenza virus (HPAIV) is considered a global threat to both human health and the poultry industry. MicroRNAs (miRNA) can modulate the immune system by affecting gene expression patterns in HPAIV-infected chickens. Objectives: To gain further insights into the role of miRNAs in immune responses against H5N1 infection, as well as the development of strategies for breeding disease-resistant chickens, we characterized miRNA expression patterns in tracheal tissues from H5N1-infected Ri chickens. Methods: miRNAs expression was analyzed from two H5N1-infected Ri chicken lines using small RNA sequencing. The target genes of differentially expressed (DE) miRNAs were predicted using miRDB. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis were then conducted. Furthermore, using quantitative real-time polymerase chain reaction, we validated the expression levels of DE miRNAs (miR-22-3p, miR-146b-3p, miR27b-3p, miR-128-3p, miR-2188-5p, miR-451, miR-205a, miR-203a, miR-21-3p, and miR-200a3p) from all comparisons and their immune-related target genes. Results: A total of 53 miRNAs were significantly expressed in the infection samples of the resistant compared to the susceptible line. Network analyses between the DE miRNAs and target genes revealed that DE miRNAs may regulate the expression of target genes involved in the transforming growth factor-beta, mitogen-activated protein kinase, and Toll-like receptor signaling pathways, all of which are related to influenza A virus progression. Conclusions: Collectively, our results provided novel insights into the miRNA expression patterns of tracheal tissues from H5N1-infected Ri chickens. More importantly, our findings offer insights into the relationship between miRNA and immune-related target genes and the role of miRNA in HPAIV infections in chickens.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.7
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• pp.954-960
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• 2008

MiRNAs (microRNAs) are a class of small non-coding RNA molecules of ~21 nucleotides that down- regulate the expression of target genes at post-transcriptional level. In this study, we first accomplished a preliminary scan of miRNA expression using 65 and 90 day fetal pig skeletal muscle samples by microarray hybridization, and 34 miRNAs showed strong positive signals. Five of these miRNAs were selected for further investigation by real-time RT-PCR. The statistical analyses indicated that three miRNAs exhibited significant differential expression (p<0.05) during porcine muscle development from 65 to 90 days of gestation, e.g., miR-24 and miR-424 were down-regulated while miR-133a was up-regulated. Multi-tissue RT-PCR was performed to detect the expression patterns of the five miRNA precursors. The results showed that most of these precursor miRNAs were ubiquitously expressed in different porcine tissues.

• Animal Bioscience
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• v.35 no.9
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• pp.1327-1339
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• 2022

Objective: Fat deposition in poultry is an important factor in production performance and meat quality research. miRNAs also play important roles in regulating adipocyte differentiation process. This study was to investigate the expression patterns of miRNAs in duck adipocytes after differentiation and explore the role of miR-214 in regulating carnitine palmitoyltransferases 2 (CPT2) gene expression during duck adipocyte differentiation. Methods: Successful systems for the isolation, culture, and induction of duck primary fat cells was developed in the experiment. Using Illumina next-generation sequencing, the miRNAs libraries of duck adipocytes were established. miRanda was used to predict differentially expressed (DE) miRNAs and their target genes. The expression patterns of miR-214 and CPT2 during the differentiation were verified by quantitative real-time polymerase chain reaction and western blot. Luciferase reporter assays were used to explore the specific regions of CPT2 targeted by miR-214. We used a miR-214 over-expression strategy in vitro to further investigate its effect on differentiation process and CPT2 gene transcription. Results: There were 481 miRNAs identified in duck adipocytes, included 57 DE miRNA candidates. And the 1,046 targets genes of DE miRNAs were mainly involved in p53 signaling, FoxO signaling, and fatty acid metabolism pathways. miR-214 and CPT2 showed contrasting expression patterns before and after differentiation, and they were selected for further research. The expression of miR-214 was decreased during the first 3 days of duck adipocytes differentiation, and then increased, while the expression of CPT2 increased both in the transcriptional and protein level. The luciferase assay suggested that miR-214 targets the 3'untranslated region of CPT2. Overexpression of miR-214 not only promoted the formation of lipid droplets but also decreased the protein abundance of CPT2. Conclusion: Current study reports the expression profile of miRNAs in duck adipocytes differentiated for 4 days. And miR-214 has been proved to have the regulator potential for fat deposition in duck.

• Journal of Veterinary Science
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• v.21 no.6
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• pp.81.1-81.10
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• 2020

Background: Although previous in vivo studies explored urinary microRNA (miRNA), there is no agreement on nephrotoxicity-specific miRNA biomarkers. Objectives: In this study, we assessed whether urinary miRNAs could be employed as biomarkers for nephrotoxicity. Methods: For this, literature-based candidate miRNAs were identified by reviewing the previous studies. Female Sprague-Dawley rats received subcutaneous injections of a single dose or repeated doses (3 consecutive days) of gentamicin (GEN; 137 or 412 mg/kg). The expression of miRNAs was analyzed by real-time reverse transcription-polymerase chain reaction in 16 h pooled urine from GEN-treated rats. Results: GEN-induced acute kidney injury was confirmed by the presence of tubular necrosis. We identified let-7g-5p, miR-21-3p, 26b-3p, 192-5p, and 378a-3p significantly upregulated in the urine of GEN-treated rats with the appearance of the necrosis in proximal tubules. Specifically, miR-26-3p, 192-5p, and 378a-3p with highly expressed levels in urine of rats with GEN-induced acute tubular injury were considered to have sensitivities comparable to clinical biomarkers, such as blood urea nitrogen, serum creatinine, and urinary kidney injury molecule protein. Conclusions: These results indicated the potential involvement of urinary miRNAs in chemical-induced nephrotoxicity, suggesting that certain miRNAs could serve as biomarkers for acute nephrotoxicity.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.7
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• pp.3203-3207
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• 2012

Backgrounds: To investigate the inhibiting effects of multi-target anti-microRNA antisense oligonucleotide (MTg-AMOs) on proliferation and migration of human gastric cancer cells. Methods: Single anti-microRNA antisense oligonucleotides (AMOs) and MTg-AMOs for miR-221, 21, and 106a were designed and transfected into SGC7901, a gastric cancer cell line, to target the activity of these miRNAs. Their expression was analyzed using stem-loop RT-PCR and effects of MTg-AMOs on human gastric cancer cells were determined using the following two assay methods: CCK8 for cell proliferation and transwells for migration. Results: In the CCK-8 cell proliferation assay, $0.6{\mu}mol/L$ was selected as the preferred concentration of MTg-AMOs and incubation time was 72 hours. Under these experimental conditions, MTg-AMOs demonstrated better suppression of the expression of miR-221, miR-106a, miR-21 in gastric cancer cells than that of single AMOs (P = 0.014, 0.024; 0.038, respectively). Migration activity was also clearly decreased as compared to those in randomized and blank control groups ($28{\pm}4$ Vs $54{\pm}3$, P <0.01; $28{\pm}4$ Vs $59{\pm}4$, P < 0.01). Conclusions: MTg-AMOs can specifically inhibit the expression of multiple miRNAs, and effectively antagonize proliferation and migration of gastric cancer cells promoted by oncomirs.

• BMB Reports
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• v.42 no.9
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• pp.593-598
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• 2009

Cell cycle progression is regulated by both transcriptional and post-transcriptional mechanisms. MicroRNAs (miRNAs) emerge as a new class of small non-coding RNA regulators of cell cycle as recent evidence suggests. It is hypothesized that expression of specific miRNAs oscillates orderly along with cell cycle progression. However, the oscillated expression patterns of many candidate miRNAs have yet to be determined. Here, we describe miRNA expression profiling in double-thymidine synchronized HeLa cells as cell cycle progresses. Twenty-five differentially expressed miRNAs were classified into five groups based on their cell cycle-dependent expression patterns. The cyclic expression of six miRNAs (miR-221, let-7a, miR-21, miR-34a, miR-24, miR-376b) was validated by real-time quantitative RT-PCR (qRT-PCR). These results suggest that specific miRNAs, along with other key factors are required for maintaining and regulating proper cell cycle progression. The study deepens our understanding on cell cycle regulation.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.1
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• pp.45-48
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• 2014

Aims: Early diagnosis is important for cervical cancer treatment. This study aimed to characteriz the microRNA profile and target gene protein levels of cervical cancers in Uygur women for application in early diagnosis. Methods: The profiles of miRNA in cervical cancer and chronic cervicitis were analyzed with miRNAmicroarray V4.0. The expression of miR-101 was detected by real-time PCR and locked nucleotide acid in situ hybridization (LNA-ISH). Cox-2 protein levels were assessed by immunohistochemistry. Results: The microarray identified a set of 12 miRNAs significantly decreased in cervical cancer in comparison to the control group. Quantitative RT-PCR analysis showed miR-101 to be significantly downregulated in cancer tissues (p<0.05) while LNA-ISH showed miR-101 positive rates of 80% (20/25) and 8% (5/25) (p<0.05) in the control and cervical cancer groups. Cox-2 positive rates of cervical cancer and control groups were 84% (21/25) and 8% (2/25) (p<0.05). Conclusions: Use of down-regulation of miR-101 and up-regulation of Cox-2 as markers may play a role in early diagnosis of cervical cancer in Uygur women.