• Title/Summary/Keyword: MicroRNAs (miRNA)

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MiR-99a Inhibits Cell Proliferation and Tumorigenesis through Targeting mTOR in Human Anaplastic Thyroid Cancer

  • Huang, Hou-Gang;Luo, Xi;Wu, Shuai;Jian, Bin
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.12
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    • pp.4937-4944
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    • 2015
  • MicroRNAs (miRNAs) are emerging as critical regulators in carcinogenesis and tumor progression. Recently, miR-99a has been reported as a tumor suppressor gene in various human cancers, but its functions in the context of anaplastic thyroid cancer (ATC) remain unknown. In this study, we reported that miR-99a was commonly downregulated in ATC tissue specimens and cell lines with important functional consequences. Overexpression of miR-99a not only dramatically reduced ATC cell viability by inducing cell apoptosis and accumulation of cells at G1 phase, but also inhibited tumorigenicity in vivo. We then screened and identified a novel miR-99a target, mammalian target of rapamycin (mTOR), and it was further confirmed by luciferase assay. Up-regulation of miR-99a would markedly reduce the expression of mTOR and its downstream phosphorylated proteins (p-4E-BP1 and p-S6K1). Similar to restoring miR-99a expression, mTOR down-regulation suppressed cell viability and increased cell apoptosis, whereas restoration of mTOR expression significantly reversed the miR-99a antitumor activity and the inhibition of mTOR/p-4E-BP1/p-S6K1 signal pathway profile. In clinical specimens and cell lines, mTOR was commonly overexpressed and its protein levels were statistically inversely correlated with miR-99a expression. Taken together, our results demonstrated for the first time that miR-99a functions as a tumor suppressor and plays an important role in inhibiting the tumorigenesis through targeting the mTOR/p-4E-BP1/p-S6K1 pathway in ATC cells. Given these, miR-99a may serve as a novel prognostic/diagnostic and therapeutic target for treating ATC.

Roles of MiR-101 and its Target Gene Cox-2 in Early Diagnosis of Cervical Cancer in Uygur Women

  • Lin, Chen;Huang, Fei;Zhang, Ya-Jing;Tuokan, Talafu;Kuerban, Gulinaer
    • 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.

Single Nucleotide Polymorphisms in miR-149 (rs2292832) and miR-101-1 (rs7536540) Are Not Associated with Hepatocellular Carcinoma in Thai Patients with Hepatitis B Virus Infection

  • Pratedrat, Pornpitra;Sopipong, Watanyoo;Makkoch, Jarika;Praianantathavorn, Kesmanee;Chuaypen, Natthaya;Tangkijvanich, Pisit;Payungporn, Sunchai
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.15
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    • pp.6457-6461
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    • 2015
  • MicroRNAs directly and indirectly influence many biological processes such as apoptosis, cell maintenance, and immune responses, impacting on tumor genesis and metastasis. They modulate gene expression at the posttranscriptional level and are associated with progression of liver disease. Hepatocellular carcinoma (HCC) is a cancer which mostly occurs in males. There are many factors affect HCC development, for example, hepatitis B virus (HBV), hepatitis C virus (HCV) and human immunodeficiency virus (HIV), co-infection, environmental factors including alcohol, aflatoxin consumption and host-related factors such as age, gender immune response, microRNA and single nucleotide polymorphisms (SNPs). Chronic infection with the hepatitis B virus is the major factor leading to HCC progression since it causes the liver injury. At present, there are many reports regarding the association of SNPs on miRNAs and the HCC progression. In this research, we investigated the role of miR-149 (rs2292832) and miR-101-1 (rs7536540) with HCC progression in Thai population. The study included 289 Thai subjects including 104 HCC patients, 90 patients with chronic hepatitis B virus infection (CHB) and 95 healthy control subjects. The allele and genotype of rs2292832 and rs7536540 polymorphisms were determined by TaqMan real-time PCR assay. Our results revealed no significant association between miR-149 (rs2292832) and miR-101-1 (rs7536540) and the risk of HCC in our Thai population. However, this research is the first study of miR-149 (rs2292832) and miR-101-1 (rs7536540) in HCC in Thai populations and the results need to be confirmed with a larger population.

miR-195/miR-497 Regulate CD274 Expression of Immune Regulatory Ligands in Triple-Negative Breast Cancer

  • Yang, Lianzhou;Cai, Yuchen;Zhang, Dongsheng;Sun, Jian;Xu, Chenyu;Zhao, Wenli;Jiang, Wenqi;Pan, Chunhua
    • Journal of Breast Cancer
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    • v.21 no.4
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    • pp.371-381
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    • 2018
  • Purpose: Immune suppression is common in patients with advanced breast cancer but the mechanisms underlying this phenomenon have not been sufficiently studied. In this study, we aimed to identify B7 family members that were able to predict the immune status of patients, and which may serve as potential targets for the treatment of breast cancer. We also aimed to identify microRNAs that may regulate the expression of B7 family members. Methods: The Cancer Genome Atlas data from 1,092 patients with breast cancer, including gene expression, microRNA expression and survival data, were used for statistical and survival analyses. Polymerase chain reaction and Western blot were used to measure messenger RNA and protein expression, respectively. Luciferase assay was used to investigate direct microRNA target. Results: Bioinformatic analysis predicted that microRNA (miR)-93, miR-195, miR-497, and miR-340 are potential regulators of the immune evasion of breast cancer cells, and that they exert this function by targeting CD274, PDCD1LG2, and NCR3LG1. We chose CD274 for further investigations. We found that miR-195, miR-497, and CD274 expression levels were inversely correlated in MDA-MB-231 cells, and miR-195 and miR-497 expressions mimic inhibited CD274 expression in vitro. Mechanistic investigations demonstrated that miR-195 and miR-497 directly target CD274 3' untranslated region. Conclusion: Our data indicated that the level of B7 family members can predict the prognosis of breast cancer patients, and miR-195/miR-497 regulate CD274 expression in triple negative breast cancer. This regulation may further influence tumor progression and the immune tolerance mechanism in breast cancer and may be able to predict the effect of immunotherapy on patients.

Associations of Single Nucleotide Polymorphisms in miR-146a, miR-196a, miR-149 and miR-499 with Colorectal Cancer Susceptibility

  • Du, Wei;Ma, Xue-Lei;Zhao, Chong;Liu, Tao;Du, Yu-Liang;Kong, Wei-Qi;Wei, Ben-Ling;Yu, Jia-Yun;Li, Yan-Yan;Huang, Jing-Wen;Li, Zi-Kang;Liu, Lei
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.2
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    • pp.1047-1055
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    • 2014
  • Background: MicroRNAs (miRNAs) are an abundant class of endogenous small non-coding RNAs of 20-25 nucleotides in length that function as negative gene regulators. MiRNAs play roles in most biological processes, as well as diverse human diseases including cancer. Recently, many studies investigated the association between SNPs in miR-146a rs2910164, miR-196a2 rs11614913, miR-149 rs229283, miR-499 rs3746444 and colorectal cancer (CRC), which results have been inconclusive. Methodology/Principal Findings: PubMed, EMBASE, CNKI databases were searched with the last search updated on November 5, 2013. For miR-196a2 rs11614913, a significantly decreased risk of CRC development was observed under three genetic models (dominant model: OR = 0.848, 95%CI: 0.735-0.979, P = 0.025; recessive model: OR = 0.838, 95%CI: 0.721-0.974, P = 0.021; homozygous model: OR = 0.754, 95%CI: 0.627-0.907, P = 0.003). In the subgroup analyses, miR-$196a2^*T$ variant was associated with a significantly decreased susceptibility of CRC (allele model: OR = 0.839, 95%CI: 0.749-0.940, P = 0.000; dominant model: OR = 0.770, 95%CI: 0.653-0.980, P = 0.002; recessive model: OR = 0.802, 95%CI: 0.685-0.939, P = 0.006; homozygous model: OR = 0.695, 95%CI: 0.570-0.847, P = 0.000). As for miR-149 rs2292832, the two genetic models (recessive model: OR = 1.199, 95% CI 1.028-1.398, P = 0.021; heterozygous model: OR = 1.226, 95% CI 1.039-1.447, P = 0.013) demonstrated increased susceptibility to CRC. On subgroup analysis, significantly increased susceptibility of CRC was found in the genetic models (recessive model: OR = 1.180, 95% CI 1.008-1.382, P = 0.040; heterozygous model: OR = 1.202, 95% CI 1.013-1.425, P = 0.013) in the Asian group. Conclusions: These findings supported that the miR-196a2 rs11614913 and miR-149 rs2292832 polymorphisms may contribute to susceptibility to CRC.

The Essential Function of miR-5739 in Embryonic Muscle Development

  • Ji-Heon Lee;Min Sup Kim;Jin-seop Lee;Dong Hyun Lee;Chansol Park;Dong Hyuk Lee;Eun-Young Kim;Hyung Min Chung
    • International Journal of Stem Cells
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    • v.16 no.2
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    • pp.145-155
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    • 2023
  • Background and Objectives: Embryologically, mesodermal development is closely related to the development of various organs such as muscles, blood vessels, and hearts, which are the main organs that make up the body. However, treatment for mesoderm developmental disorders caused by congenital or acquired factors has so far relied on surgery and drug treatment for symptom relief, and more fundamentally, treatment for mesoderm developmental disorders is needed. Methods and Results: In our study, microRNA (miRNA), which plays an important role in the mesoderm development process, was identified and the developmental function was evaluated. miRNAs consist of small nucleotides, which act as transcription factors that bind to the 3' untranslated region and suppressed target gene expression. We constructed the human embryonic stem cell (hESC) knockout cell line and analyzed the function and characteristics of miR-5739, which plays an important role in mesoderm lineage. miR-5739 acts as a transcription factor targeting SMA, Brachyury T, Hand1, which controls muscle proliferation and differentiation, and KDR gene, which regulates vessel formation in vitro. In vivo results suggest a role in regulating muscle proliferation and differentiation. Gene ontology analysis confirmed that the miR-5739 is closely related to genes that regulate muscle and vessel proliferation and differentiation. Importantly, abnormal expression of miR-5739 was detected in somatic cells derived from patients with congenital muscle disease. Conclusions: Our study demonstrate that miR-5739 gene function significantly affects transcriptional circuits that regulate muscle and vascular differentiation during embryonic development.

The Role of Extracellular Vesicles in Senescence

  • Oh, Chaehwan;Koh, Dahyeon;Jeon, Hyeong Bin;Kim, Kyoung Mi
    • Molecules and Cells
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    • v.45 no.9
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    • pp.603-609
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    • 2022
  • Cells can communicate in a variety of ways, such as by contacting each other or by secreting certain factors. Recently, extracellular vesicles (EVs) have been proposed to be mediators of cell communication. EVs are small vesicles with a lipid bilayer membrane that are secreted by cells and contain DNA, RNAs, lipids, and proteins. These EVs are secreted from various cell types and can migrate and be internalized by recipient cells that are the same or different than those that secrete them. EVs harboring various components are involved in regulating gene expression in recipient cells. These EVs may also play important roles in the senescence of cells and the accumulation of senescent cells in the body. Studies on the function of EVs in senescent cells and the mechanisms through which nonsenescent and senescent cells communicate through EVs are being actively conducted. Here, we summarize studies suggesting that EVs secreted from senescent cells can promote the senescence of other cells and that EVs secreted from nonsenescent cells can rejuvenate senescent cells. In addition, we discuss the functional components (proteins, RNAs, and other molecules) enclosed in EVs that enter recipient cells.

Lactate promotes vascular smooth muscle cell switch to a synthetic phenotype by inhibiting miR-23b expression

  • Hu, Yanchao;Zhang, Chunyan;Fan, Yajie;Zhang, Yan;Wang, Yiwen;Wang, Congxia
    • The Korean Journal of Physiology and Pharmacology
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    • v.26 no.6
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    • pp.519-530
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    • 2022
  • Recent research indicates that lactate promotes the switching of vascular smooth muscle cells (VSMCs) to a synthetic phenotype, which has been implicated in various vascular diseases. This study aimed to investigate the effects of lactate on the VSMC phenotype switch and the underlying mechanism. The CCK-8 method was used to assess cell viability. The microRNAs and mRNAs levels were evaluated using quantitative PCR. Targets of microRNA were predicted using online tools and confirmed using a luciferase reporter assay. We found that lactate promoted the switch of VSMCs to a synthetic phenotype, as evidenced by an increase in VSMC proliferation, mitochondrial activity, migration, and synthesis but a decrease in VSMC apoptosis. Lactate inhibited miR-23b expression in VSMCs, and miR-23b inhibited VSMC's switch to the synthetic phenotype. Lactate modulated the VSMC phenotype through downregulation of miR-23b expression, suggesting that overexpression of miR-23b using a miR-23b mimic attenuated the effects of lactate on VSMC phenotype modulation. Moreover, we discovered that SMAD family member 3 (SMAD3) was the target of miR-23b in regulating VSMC phenotype. Further findings suggested that lactate promotes VSMC switch to synthetic phenotype by targeting SMAD3 and downregulating miR-23b. These findings suggest that correcting the dysregulation of miR-23b/SMAD3 or lactate metabolism is a potential treatment for vascular diseases.

MiR-323-5p acts as a Tumor Suppressor by Targeting the Insulin-like Growth Factor 1 Receptor in Human Glioma Cells

  • Lian, Hai-Wei;Zhou, Yun;Jian, Zhi-Hong;Liu, Ren-Zhong
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.23
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    • pp.10181-10185
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    • 2015
  • Background: MicroRNAs, small noncoding RNA molecules, can regulate mammalian cell growth, apoptosis and differentiation by controlling the expression of target genes. The aim of this study was to investigate the function of miR-323-5p in the glioma cell line, U251. Materials and Methods: After over-expression of miR-323-5p using miR-323-5p mimics, cell growth, apoptosis and migration were tested by MTT, flow cytometry and cell wound healing assay, respectively. We also assessed the influence of miR-323-5p on the mRNA expression of IGF-1R by quantitative real-time reverse transcriptase PCR (qRT-PCR), and on the protein levels by Western blot analysi. In addition, dual-luciferase reporter assays were performed to determine the target site of miR-323-5p to IGF-1R 3'UTR. Results: Our findings showed that over-expression of miR-323-5p could promote apoptosis of U251 and inhibit the proliferation and migration of the glioma cells. Conclusions: This study demonstrated that increased expression of miR-323-5p might be related to glioma progression, which indicates a potential role of miR-323-5p for clinical therapy.

Development of a New Duplex Real-Time Polymerase Chain Reaction Assay for Detection of Dicer in G. gallus

  • Ji, Xiaolin;Wang, Qi;Gao, Yulong;Wang, Yongqiang;Qin, Liting;Qi, Xiaole;Gao, Honglei;Wang, Xiaomei
    • Journal of Microbiology and Biotechnology
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    • v.23 no.5
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    • pp.630-636
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    • 2013
  • Recently, there has been a growing body of evidence showing that cellular microRNAs (miRNAs) are involved in virus-host interactions. Numerous studies have focused on analyses of the expression profiles of cellular miRNAs, but the expression patterns of Dicer, which is responsible for the generation of miRNAs, have only rarely been explored in Gallus gallus. We developed a duplex real-time reverse transcriptase polymerase chain reaction (RT-PCR) assay for the relative quantification of the mRNAs of Dicer and ${\beta}$-actin in G. gallus. To apply this method, the expression of Dicer in avian cells after infection with avian leukosis virus subgroup J (ALV-J) was detected using our established duplex real-time RT-PCR. The duplex real-time RT-PCR assay is sufficiently sensitive, specific, accurate, reproducible, and cost-effective for the detection of Dicer in G. gallus. Furthermore, this study, for the first time, demonstrated that ALV-J can induce differential expression of Dicer mRNA in the ALV-J-infected cells.