Displaying publications 61 - 80 of 116 in total

Abstract:
Sort:
  1. Fulltext Mapping a Circular RNA-microRNA-mRNA-Signaling Regulatory Axis That Modulates Stemness Properties of Cancer Stem Cell Populations in Colorectal Cancer Spheroid Cells
    Rengganaten V, Huang CJ, Tsai PH, Wang ML, Yang YP, Lan YT, et al.
    Int J Mol Sci, 2020 Oct 23;21(21).
    PMID: 33114016 DOI: 10.3390/ijms21217864
    Spheroidal cancer cell cultures have been used to enrich cancer stem cells (CSC), which are thought to contribute to important clinical features of tumors. This study aimed to map the regulatory networks driven by circular RNAs (circRNAs) in CSC-enriched colorectal cancer (CRC) spheroid cells. The spheroid cells established from two CRC cell lines acquired stemness properties in pluripotency gene expression and multi-lineage differentiation capacity. Genome-wide sequencing identified 1503 and 636 circRNAs specific to the CRC parental and spheroid cells, respectively. In the CRC spheroids, algorithmic analyses unveiled a core network of mRNAs involved in modulating stemness-associated signaling pathways, driven by a circRNA-microRNA (miRNA)-mRNA axis. The two major circRNAs, hsa_circ_0066631 and hsa_circ_0082096, in this network were significantly up-regulated in expression levels in the spheroid cells. The two circRNAs were predicted to target and were experimentally shown to down-regulate miR-140-3p, miR-224, miR-382, miR-548c-3p and miR-579, confirming circRNA sponging of the targeted miRNAs. Furthermore, the affected miRNAs were demonstrated to inhibit degradation of six mRNA targets, viz. ACVR1C/ALK7, FZD3, IL6ST/GP130, SKIL/SNON, SMAD2 and WNT5, in the CRC spheroid cells. These mRNAs encode proteins that are reported to variously regulate the GP130/Stat, Activin/Nodal, TGF-β/SMAD or Wnt/β-catenin signaling pathways in controlling various aspects of CSC stemness. Using the CRC spheroid cell model, the novel circRNA-miRNA-mRNA axis mapped in this work forms the foundation for the elucidation of the molecular mechanisms of the complex cellular and biochemical processes that determine CSC stemness properties of cancer cells, and possibly for designing therapeutic strategies for CRC treatment by targeting CSC.
    Matched MeSH terms: MicroRNAs/genetics*
  2. Fulltext The Interplay between MicroRNAs and Cellular Components of Tumour Microenvironment (TME) on Non-Small-Cell Lung Cancer (NSCLC) Progression
    Lee SS, Cheah YK
    J Immunol Res, 2019;2019:3046379.
    PMID: 30944831 DOI: 10.1155/2019/3046379
    Cellular components of the tumour microenvironment (TME) are recognized to regulate the hallmarks of cancers including tumour proliferation, angiogenesis, invasion, and metastasis, as well as chemotherapeutic resistance. The linkage between miRNA, TME, and the development of the hallmarks of cancer makes miRNA-mediated regulation of TME a potential therapeutic strategy to complement current cancer therapies. Despite significant advances in cancer therapy, lung cancer remains the deadliest form of cancer among males in the world and has overtaken breast cancer as the most fatal cancer among females in more developed countries. Therefore, there is an urgent need to develop more effective treatments for NSCLC, which is the most common type of lung cancer. Hence, this review will focus on current literature pertaining to antitumour or protumourigenic effects elicited by nonmalignant stromal cells of TME in NSCLC through miRNA regulation as well as current status and future prospects of miRNAs as therapeutic agents or targets to regulate TME in NSCLC.
    Matched MeSH terms: MicroRNAs/genetics*
  3. Evaluation of factors influencing the development of late Marek's disease virus-induced immunosuppression: virus pathotype and host sex
    Faiz NM, Cortes AL, Guy JS, Fletcher OJ, Cimino T, Gimeno IM
    Avian Pathol, 2017 Aug;46(4):376-385.
    PMID: 28151004 DOI: 10.1080/03079457.2017.1290214
    Marek's disease virus (MDV) is a herpesvirus that induces lymphoma and immunosuppression in chickens. MDV-induced immunosuppression (MDV-IS) is complex and can be divided into two phases: early-MDV-IS associated with cytolytic infection in the lymphoid organs in chickens lacking maternal antibodies against MDV (MAbs) and late-MDV-IS that appears later in the pathogenesis and occurs even in chickens bearing MAbs. We have recently developed a model to reproduce late-MDV-IS under laboratory conditions. This model evaluates late-MDV-IS indirectly by assessing the effect of MDV infection on the efficacy of infectious laryngotracheitis (ILT) vaccines against challenge with ILT virus. In the present study, we have used this model to investigate the role of two factors (MDV pathotype and host sex) on the development of late-MDV-IS. Five MDV strains representing three different pathotypes: virulent (vMDV; 617A, GA), very virulent (vvMDV; Md5), and very virulent plus (vv+MDV; 648A, 686), were evaluated. Only vv+ strains were able to induce late-MDV-IS. An immunosuppression rank (IS-rank) was established based on the ability of MDV to reduce the efficacy of chicken embryo origin vaccine (values go from 0 to 100, with 100 being the highest immunosuppressive ability). The IS-rank of the evaluated MDV strains ranged from 5.97 (GA) to 20.8 (617A) in the vMDV strains, 5.97 to 16.24 in the vvMDV strain Md5, and 39.08 to 68.2 in the vv+ strains 648A and 686. In this study both male and female chickens were equally susceptible to MDV-IS by vv+MDV 686. Our findings suggest that late-MDV-IS is a unique feature of vv+ strains.
    Matched MeSH terms: MicroRNAs/genetics
  4. miR-608 regulates apoptosis in human lung adenocarcinoma via regulation of AKT2
    Othman N, Nagoor NH
    Int J Oncol, 2017 Dec;51(6):1757-1764.
    PMID: 29075783 DOI: 10.3892/ijo.2017.4174
    Lung cancer remains a major health problem with a low 5-year survival rate of patients. Recent studies have shown that dysregulation of microRNAs (miRNAs) are prevalent in lung cancer and these aberrations play a significant role in the progression of tumour progression. In the present study, bioinformatics analyses was employed to predict potential miR-608 targets, which are associated with signaling pathways involved in cancer. Luciferase reporter assay identified AKT2 as a novel target of miR-608, and suppression of its protein levels was validated through western blot analysis. Zebrafish embryos were microinjected with cells transfected with miR-608 to elucidate the role of miR-608 in vivo, and immunostained with antibodies to detect activated caspase-3. We present the first evidence that miR-608 behaves as a tumour suppressor in A549 and SK-LU-1 cells through the regulation of AKT2, suggesting that selective targeting of AKT2 via miR-608 may be developed as a potential therapeutic strategy for miRNA-based non-small cell lung cancer (NSCLC) therapy.
    Matched MeSH terms: MicroRNAs/genetics*
  5. Non-coding RNAs as therapeutic targets for preventing myocardial ischemia-reperfusion injury
    Ong SB, Katwadi K, Kwek XY, Ismail NI, Chinda K, Ong SG, et al.
    Expert Opin Ther Targets, 2018 03;22(3):247-261.
    PMID: 29417868 DOI: 10.1080/14728222.2018.1439015
    INTRODUCTION: New treatments are required to improve clinical outcomes in patients with acute myocardial infarction (AMI), for reduction of myocardial infarct (MI) size and preventing heart failure. Following AMI, acute ischemia/reperfusion injury (IRI) ensues, resulting in cardiomyocyte death and impaired cardiac function. Emerging studies have implicated a fundamental role for non-coding RNAs (microRNAs [miRNA], and more recently long non-coding RNAs [lncRNA]) in the setting of acute myocardial IRI. Areas covered: In this article, we discuss the roles of miRNAs and lncRNAs as potential biomarkers and therapeutic targets for the detection and treatment of AMI, review their roles as mediators and effectors of cardioprotection, particularly in the settings of interventions such as ischemic pre- and post-conditioning (IPC & IPost) as well as remote ischemic conditioning (RIC), and highlight future strategies for targeting ncRNAs to reduce MI size and prevent heart failure following AMI. Expert opinion: Investigating the roles of miRNAs and lncRNAs in the setting of AMI has provided new insights into the pathophysiology underlying acute myocardial IRI, and has identified novel biomarkers and therapeutic targets for detecting and treating AMI. Pharmacological and genetic manipulation of these ncRNAs has the therapeutic potential to improve clinical outcomes in AMI patients.
    Matched MeSH terms: MicroRNAs/genetics
  6. DNA-RNA complementation on silicon wafer for thyroid cancer determination
    Gopinath SCB, Xuan S
    Biotechnol Appl Biochem, 2021 Jun;68(3):554-559.
    PMID: 32460382 DOI: 10.1002/bab.1961
    One of the current issues with thyroid tumor is early diagnosis as it makes the higher possibility of curing. This research was focused to detect and quantify the level of specific target sequence complementation of miR-222 with capture DNA sequence on interdigitated electrode (IDE) sensor. The aluminum electrode with the gap and finger sizes of 10 µm was fabricated on silicon wafer, further the surface was amine-functionalized for accommodating carboxylated-DNA probe. With DNA-target RNA complementation, the detection limit was attained to be 1 fM as estimated by a linear regression analysis [y = 1.5325x - 2.1171 R² = 0.9065] and the sensitivity was at the similar level. Current responses were higher by increasing the target RNA sequence concentrations. Control experiments with mismatched/noncomplementary sequences were failed to complement the capture DNA sequence immobilized on IDE, indicating the specific target validation. This research helps diagnosing and identifying the progression with thyroid tumor and miRNA being a potential "marker" in atypia diagnosis.
    Matched MeSH terms: MicroRNAs/genetics*
  7. MicroRNAs as Biomarker for Breast Cancer
    Aggarwal T, Wadhwa R, Gupta R, Paudel KR, Collet T, Chellappan DK, et al.
    Endocr Metab Immune Disord Drug Targets, 2020;20(10):1597-1610.
    PMID: 32342824 DOI: 10.2174/1871530320666200428113051
    Regardless of advances in detection and treatment, breast cancer affects about 1.5 million women all over the world. Since the last decade, genome-wide association studies (GWAS) have been extensively conducted for breast cancer to define the role of miRNA as a tool for diagnosis, prognosis and therapeutics. MicroRNAs are small, non-coding RNAs that are associated with the regulation of key cellular processes such as cell multiplication, differentiation, and death. They cause a disturbance in the cell physiology by interfering directly with the translation and stability of a targeted gene transcript. MicroRNAs (miRNAs) constitute a large family of non-coding RNAs, which regulate target gene expression and protein levels that affect several human diseases and are suggested as the novel markers or therapeutic targets, including breast cancer. MicroRNA (miRNA) alterations are not only associated with metastasis, tumor genesis but also used as biomarkers for breast cancer diagnosis or prognosis. These are explained in detail in the following review. This review will also provide an impetus to study the role of microRNAs in breast cancer.
    Matched MeSH terms: MicroRNAs/genetics
  8. Fulltext MicroRNAs regulating cluster of differentiation 46 (CD46) in cardioembolic and non-cardioembolic stroke
    Tan JR, Tan KS, Yong FL, Armugam A, Wang CW, Jeyaseelan K, et al.
    PLoS One, 2017;12(2):e0172131.
    PMID: 28199366 DOI: 10.1371/journal.pone.0172131
    Ischemic stroke is a major cause of mortality and morbidity globally. Among the ischemic stroke subtypes, cardioembolic stroke is with poor functional outcome (Modified Rankin score ≥ 2). Early diagnosis of cardioembolic stroke will prove beneficial. This study examined the microRNAs targeting cluster of differentiation 46 (CD46), a potential biomarker for cardioembolic stroke. CD46 mRNA level was shown to be differentially expressed (p < 0.001) between cardioembolic stroke (median = 1.32) and non-cardioembolic stroke subtypes (large artery stroke median = 5.05; small vessel stroke median = 6.45). Bioinformatic search showed that miR-19a, -20a, -185 and -374b were found to target CD46 mRNA and further verified by luciferase reporter assay. The levels of miRNAs targeting CD46 were significantly reduced (p < 0.05) in non-cardioembolic stroke patients (large artery stroke median: miR-19a = 0.63, miR-20a = 0.42, miR-185 = 0.32, miR-374b = 0.27; small artery stroke median: miR-19a = 0.07, miR-20a = 0.06, miR-185 = 0.07, miR-374b = 0.05) as compared to cardioembolic stroke patients (median: miR-19a = 2.69, miR-20a = 1.36, miR-185 = 1.05, miR-374b = 1.23). ROC curve showed that the miRNAs could distinguish cardioembolic stroke from non-cardioembolic stroke with better AUC value as compared to CD46. Endogenous expression of CD46 in Human Umbilical Vein Endothelial Cells (HUVECs) were found to be regulated by miR-19a and miR-20a. Thus implicating that miR-19a and -20a may play a role in pathogenesis of cardioembolic stroke, possibly via the endothelial cells.
    Matched MeSH terms: MicroRNAs/genetics
  9. Fulltext In Silico Prediction and Validation of Gfap as an miR-3099 Target in Mouse Brain
    Abidin SZ, Leong JW, Mahmoudi M, Nordin N, Abdullah S, Cheah PS, et al.
    Neurosci Bull, 2017 Aug;33(4):373-382.
    PMID: 28597341 DOI: 10.1007/s12264-017-0143-0
    MicroRNAs are small non-coding RNAs that play crucial roles in the regulation of gene expression and protein synthesis during brain development. MiR-3099 is highly expressed throughout embryogenesis, especially in the developing central nervous system. Moreover, miR-3099 is also expressed at a higher level in differentiating neurons in vitro, suggesting that it is a potential regulator during neuronal cell development. This study aimed to predict the target genes of miR-3099 via in-silico analysis using four independent prediction algorithms (miRDB, miRanda, TargetScan, and DIANA-micro-T-CDS) with emphasis on target genes related to brain development and function. Based on the analysis, a total of 3,174 miR-3099 target genes were predicted. Those predicted by at least three algorithms (324 genes) were subjected to DAVID bioinformatics analysis to understand their overall functional themes and representation. The analysis revealed that nearly 70% of the target genes were expressed in the nervous system and a significant proportion were associated with transcriptional regulation and protein ubiquitination mechanisms. Comparison of in situ hybridization (ISH) expression patterns of miR-3099 in both published and in-house-generated ISH sections with the ISH sections of target genes from the Allen Brain Atlas identified 7 target genes (Dnmt3a, Gabpa, Gfap, Itga4, Lxn, Smad7, and Tbx18) having expression patterns complementary to miR-3099 in the developing and adult mouse brain samples. Of these, we validated Gfap as a direct downstream target of miR-3099 using the luciferase reporter gene system. In conclusion, we report the successful prediction and validation of Gfap as an miR-3099 target gene using a combination of bioinformatics resources with enrichment of annotations based on functional ontologies and a spatio-temporal expression dataset.
    Matched MeSH terms: MicroRNAs/genetics
  10. Fulltext Selective activation of miRNAs of the primate-specific chromosome 19 miRNA cluster (C19MC) in cancer and stem cells and possible contribution to regulation of apoptosis
    Nguyen PN, Huang CJ, Sugii S, Cheong SK, Choo KB
    J Biomed Sci, 2017 Mar 07;24(1):20.
    PMID: 28270145 DOI: 10.1186/s12929-017-0326-z
    BACKGROUND: The human chromosome 19 miRNA cluster (C19MC) of 43 genes is a primate-specific miRNA cluster that may have biological significance in the genetic complexity of the primate. Despite previous reports on individual C19MC miRNA expression in cancer and stem cells, systematic studies on C19MC miRNA expression and biological functions are lacking.

    RESULTS: Cluster-wide C19MC miRNA expression profiling by microarray analysis showed wholesome C19MC activation in embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs). However, in multipotent adipose-derived mesenchymal stem cells (MSCs) and a unipotent human white pre-adipocyte cell line, only selected C19MC miRNAs were expressed. MiRNA copy number analysis also showed selective C19MC expression in cancer cells with expression patterns highly similar to those in MSCs, suggesting similar miRNA regulatory mechanisms in these cells. Selective miRNA expression also suggests complex transcriptional mechanism(s) regulating C19MC expression under specific cellular and pathological conditions. Bioinformatics analysis showed that sixteen of the C19MC miRNAs share the same "AAGUGC" seed sequence with members of the miR-302/-372 family, which are known cellular reprogramming factors. In particular, C19MC-AAGUGC-miRNAs with the nucleotides 2-7 canonical seed position as in miR-302/-372 miRNAs, may play similar roles as miR-302/-372 in induced pluripotency. A biased 3p-arm selection of the C19MC-AAGUGC-miRNAs was observed indicating that targets of the 3p species of these miRNAs may be biologically significant in regulating stemness. Furthermore, bioinformatics analysis of the putative targets of the C19MC-AAGUGC-miRNAs predicted significant involvement of signaling pathways in reprogramming, many of which contribute to promoting apoptosis by indirect activation of the pro-apoptotic proteins BAK/BAX via suppression of genes of the cell survival pathways, or by enhancing caspase-8 activation through targeting inhibitors of TRAIL-inducing apoptosis.

    CONCLUSIONS: This work demonstrated selective C19MC expression in MSCs and cancer cells, and, through miRNA profiling and bioinformatics analysis, predicted C19MC modulation of apoptosis in induced pluripotency and tumorigenesis.

    Matched MeSH terms: MicroRNAs/genetics
  11. An Overview of Circular RNAs
    Awasthi R, Singh AK, Mishra G, Maurya A, Chellappan DK, Gupta G, et al.
    Adv Exp Med Biol, 2018 9 28;1087:3-14.
    PMID: 30259353 DOI: 10.1007/978-981-13-1426-1_1
    Circular RNAs (cirRNAs) are long, noncoding endogenous RNA molecules and covalently closed continuous loop without 5'-3' polarity and polyadenylated tail which are largely concentrated in the nucleus. CirRNA regulates gene expression by modulating microRNAs and functions as potential biomarker. CirRNAs can translate in vivo to link between their expression and disease. They are resistant to RNA exonuclease and can convert to the linear RNA by microRNA which can then act as competitor to endogenous RNA. This chapter summarizes the evolutionary conservation and expression of cirRNAs, their identification, highlighting various computational approaches on cirRNA, and translation with a focus on the breakthroughs and the challenges in this new field.
    Matched MeSH terms: MicroRNAs/genetics
  12. Fulltext Role of microRNAs in antiviral responses to dengue infection
    Wong RR, Abd-Aziz N, Affendi S, Poh CL
    J Biomed Sci, 2020 Jan 03;27(1):4.
    PMID: 31898495 DOI: 10.1186/s12929-019-0614-x
    Dengue virus (DENV) is the etiological agent of dengue fever. Severe dengue could be fatal and there is currently no effective antiviral agent or vaccine. The only licensed vaccine, Dengvaxia, has low efficacy against serotypes 1 and 2. Cellular miRNAs are post-transcriptional regulators that could play a role in direct regulation of viral genes. Host miRNA expressions could either promote or repress viral replications. Induction of some cellular miRNAs could help the virus to evade the host immune response by suppressing the IFN-α/β signaling pathway while others could upregulate IFN-α/β production and inhibit the viral infection. Understanding miRNA expressions and functions during dengue infections would provide insights into the development of miRNA-based therapeutics which could be strategized to act either as miRNA antagonists or miRNA mimics. The known mechanisms of how miRNAs impact DENV replication are diverse. They could suppress DENV multiplication by directly binding to the viral genome, resulting in translational repression. Other miRNA actions include modulation of host factors. In addition, miRNAs that could modulate immunopathogenesis are discussed. Major hurdles lie in the development of chemical modifications and delivery systems for in vivo delivery. Nevertheless, advancement in miRNA formulations and delivery systems hold great promise for the therapeutic potential of miRNA-based therapy, as supported by Miravirsen for treatment of Hepatitis C infection which has successfully completed phase II clinical trial.
    Matched MeSH terms: MicroRNAs/genetics*
  13. Overexpression of miR‑361‑5p plays an oncogenic role in human lung adenocarcinoma through the regulation of SMAD2
    Othman N, Nagoor NH
    Int J Oncol, 2019 01;54(1):306-314.
    PMID: 30365047 DOI: 10.3892/ijo.2018.4602
    The silencing of Bcl‑xL in the non‑small cell lung cancer (NSCLC) cell line, A549, downregulates miR‑361‑5p expression. This study aimed to determine the biological effects of miR‑361‑5p on NSCLC, and to elucidate the molecular mechanisms through which apoptosis is regulated. MicroRNA (miRNA or miR) functional analyses were performed via transfection of miR‑361‑5p mimics and inhibitors, demonstrating that the inhibition of miR‑361‑5p induced the apoptosis of NSCLC cells. To elucidate the function of miR‑361‑5p in vivo, cells transfected with miR‑361‑5p inhibitors were microinjected into zebrafish embryos, and immunostained using antibodies to detect the active form of caspase‑3. Co-transfection with siBcl‑xL and miR‑361‑5p mimics illustrated the association between Bcl‑xL, miR‑361‑5p and apoptosis; miR‑361‑5p mimics blocked the apoptosis initiated by siBcl‑xL. Luciferase reporter assays identified mothers against decapentaplegic homolog 2 (SMAD2) as a novel target of miR‑361‑5p and the reduction of its protein level was validated by western blot analysis. To confirm the molecular mechanisms through which apoptosis is regulated, gene rescue experiments revealed that the ectopic expression of SMAD2 attenuated the inhibitory effects on apoptosis induced by miR‑361‑5p. In this study, to the best of our knowledge, we provide the first evidence that miR‑361‑5p functions as an oncomiR in A549 and SK‑LU‑1 cells through the regulation of SMAD2, suggesting that miR‑361‑5p may be employed as a potential therapeutic target for the miRNA-based therapy of NSCLC.
    Matched MeSH terms: MicroRNAs/genetics*
  14. Fulltext Exosomal miR-224 contributes to hemolymph microbiota homeostasis during bacterial infection in crustacean
    Gong Y, Wei X, Sun W, Ren X, Chen J, Aweya JJ, et al.
    PLoS Pathog, 2021 08;17(8):e1009837.
    PMID: 34379706 DOI: 10.1371/journal.ppat.1009837
    It is well known that exosomes could serve as anti-microbial immune factors in animals. However, despite growing evidences have shown that the homeostasis of the hemolymph microbiota was vital for immune regulation in crustaceans, the relationship between exosomes and hemolymph microbiota homeostasis during pathogenic bacteria infection has not been addressed. Here, we reported that exosomes released from Vibrio parahaemolyticus-infected mud crabs (Scylla paramamosain) could help to maintain the homeostasis of hemolymph microbiota and have a protective effect on the mortality of the host during the infection process. We further confirmed that miR-224 was densely packaged in these exosomes, resulting in the suppression of HSP70 and disruption of the HSP70-TRAF6 complex, then the released TRAF6 further interacted with Ecsit to regulate the production of mitochondrial ROS (mROS) and the expression of Anti-lipopolysaccharide factors (ALFs) in recipient hemocytes, which eventually affected hemolymph microbiota homeostasis in response to the pathogenic bacteria infection in mud crab. To the best of our knowledge, this is the first document that reports the role of exosome in the hemolymph microbiota homeostasis modulation during pathogen infection, which reveals the crosstalk between exosomal miRNAs and innate immune response in crustaceans.
    Matched MeSH terms: MicroRNAs/genetics*
  15. Ratiometric Detection of microRNA Using Hybridization Chain Reaction and Fluorogenic Silver Nanoclusters
    Wong ZW, Ng JF, New SY
    Chem Asian J, 2021 Dec 13;16(24):4081-4086.
    PMID: 34668337 DOI: 10.1002/asia.202101145
    miRNA (miR)-155 is a potential biomarker for breast cancers. We aimed at developing a nanosensor for miR-155 detection by integrating hybridization chain reaction (HCR) and silver nanoclusters (AgNCs). HCR serves as an enzyme-free and isothermal amplification method, whereas AgNCs provide a built-in fluorogenic detection probe that could simplify the downstream analysis. The two components were integrated by adding a nucleation sequence of AgNCs to the hairpin of HCR. The working principle was based on the influence of microenvironment towards the hosted AgNCs, whereby unfolding of hairpin upon HCR has manipulated the distance between the hosted AgNCs and cytosine-rich toehold region of hairpin. As such, the dominant emission of AgNCs changed from red to yellow in the absence and presence of miR-155, enabling a ratiometric measurement of miR with high sensitivity. The limit of detection (LOD) of our HCR-AgNCs nanosensor is 1.13 fM in buffered solution. We have also tested the assay in diluted serum samples, with comparable LOD of 1.58 fM obtained. This shows the great promise of our HCR-AgNCs nanosensor for clinical application.
    Matched MeSH terms: MicroRNAs/genetics
  16. Imbalanced expression of polycistronic miRNA in acute myeloid leukemia
    Kotaki R, Higuchi H, Ogiya D, Katahira Y, Kurosaki N, Yukihira N, et al.
    Int J Hematol, 2017 Dec;106(6):811-819.
    PMID: 28831750 DOI: 10.1007/s12185-017-2314-1
    miR-1 and miR-133 are clustered on the same chromosomal loci and are transcribed together as a single transcript that is positively regulated by ecotropic virus integration site-1 (EVI1). Previously, we described how miR-133 has anti-tumorigenic potential through repression of EVI1 expression. It has also been reported that miR-1 is oncogenic in the case of acute myeloid leukemia (AML). Here, we show that expression of miR-1 and miR-133, which have distinct functions, is differentially regulated between AML cell lines. Interestingly, the expression of miR-1 and EVI1, which binds to the promoter of the miR-1/miR-133 cluster, is correlative. The expression levels of TDP-43, an RNA-binding protein that has been reported to increase the expression, but inhibits the activity, of miR-1, were not correlated with expression levels of miR-1 in AML cells. Taken together, our observations raise the possibility that the balance of polycistronic miRNAs is regulated post-transcriptionally in a hierarchical manner possibly involving EVI1, suggesting that the deregulation of this balance may play some role in AML cells with high EVI1 expression.
    Matched MeSH terms: MicroRNAs/genetics
  17. Fulltext Identification of functionally important microRNAs from rice inflorescence at heading stage of a qDTY4.1-QTL bearing Near Isogenic Line under drought conditions
    Cheah BH, Jadhao S, Vasudevan M, Wickneswari R, Nadarajah K
    PLoS One, 2017;12(10):e0186382.
    PMID: 29045473 DOI: 10.1371/journal.pone.0186382
    A cross between IR64 (high-yielding but drought-susceptible) and Aday Sel (drought-tolerant) rice cultivars yielded a stable line with enhanced grain yield under drought screening field trials at International Rice Research Institute. The major effect qDTY4.1 drought tolerance and yield QTL was detected in the IR77298-14-1-2-10 Backcrossed Inbred Line (BIL) and its IR87705-7-15-B Near Isogenic Line (NIL) with 93.9% genetic similarity to IR64. Although rice yield is extremely susceptible to water stress at reproductive stage, currently, there is only one report on the detection of drought-responsive microRNAs in inflorescence tissue of a Japonica rice line. In this study, more drought-responsive microRNAs were identified in the inflorescence tissues of IR64, IR77298-14-1-2-10 and IR87705-7-15-B via next-generation sequencing. Among the 32 families of inflorescence-specific non-conserved microRNAs that were identified, 22 families were up-regulated in IR87705-7-15-B. Overall 9 conserved and 34 non-conserved microRNA families were found as drought-responsive in rice inflorescence with 5 conserved and 30 non-conserved families induced in the IR87705-7-15-B. The observation of more drought-responsive non-conserved microRNAs may imply their prominence over conserved microRNAs in drought response mechanisms of rice inflorescence. Gene Ontology annotation analysis on the target genes of drought-responsive microRNAs identified in IR87705-7-15-B revealed over-representation of biological processes including development, signalling and response to stimulus. Particularly, four inflorescence-specific microRNAs viz. osa-miR5485, osa-miR5487, osa-miR5492 and osa-miR5517, and two non-inflorescence specific microRNAs viz. osa-miR169d and osa-miR169f.2 target genes that are involved in flower or embryonic development. Among them, osa-miR169d, osa-miR5492 and osa-miR5517 are related to flowering time control. It is also worth mentioning that osa-miR2118 and osa-miR2275, which are implicated in the biosynthesis of rice inflorescence-specific small interfering RNAs, were induced in IR87705-7-15-B but repressed in IR77298-14-1-2-10. Further, gene search within qDTY4.1 QTL region had identified multiple copies of NBS-LRR resistance genes (potential target of osa-miR2118), subtilisins and genes implicated in stomatal movement, ABA metabolism and cuticular wax biosynthesis.
    Matched MeSH terms: MicroRNAs/genetics*
  18. Toward a Reference Gene Catalog of Human Primary Monocytes
    Mirsafian H, Ripen AM, Manaharan T, Mohamad SB, Merican AF
    OMICS, 2016 11;20(11):627-634.
    PMID: 27828772
    Transcriptome analyses based on high-throughput RNA sequencing (RNA-Seq) provide powerful and quantitative characterization of cell types and in-depth understanding of biological systems in health and disease. In this study, we present a comprehensive transcriptome profile of human primary monocytes, a crucial component of the innate immune system. We performed deep RNA-Seq of monocytes from six healthy subjects and integrated our data with 10 other publicly available RNA-Seq datasets of human monocytes. A total of 1.9 billion reads were generated, which allowed us to capture most of the genes transcribed in human monocytes, including 11,994 protein-coding genes, 5558 noncoding genes (including long noncoding RNAs, precursor miRNAs, and others), 2819 pseudogenes, and 7034 putative novel transcripts. In addition, we profiled the expression pattern of 1155 transcription factors (TFs) in human monocytes, which are the main molecules in controlling the gene transcription. An interaction network was constructed among the top expressed TFs and their targeted genes, which revealed the potential key regulatory genes in biological function of human monocytes. The gene catalog of human primary monocytes provided in this study offers significant promise and future potential clinical applications in the fields of precision medicine, systems diagnostics, immunogenomics, and the development of innovative biomarkers and therapeutic monitoring strategies.
    Matched MeSH terms: MicroRNAs/genetics
  19. Fulltext Tumor suppressor role of miR-503
    Gupta G, Chellappan DK, de Jesus Andreoli Pinto T, Hansbro PM, Bebawy M, Dua K
    Panminerva Med, 2018 Mar;60(1):17-24.
    PMID: 29164842 DOI: 10.23736/S0031-0808.17.03386-9
    MicroRNAs (miRNAs) are non-coding RNAs of around 20-25 nucleotides in length with highly conserved characteristics. They moderate post-transcriptional silencing by precisely combining with 3' untranslated regions (UTRs) of target mRNAs at a complementary site. miR‑503, an associate of the "canonical" miRNA-16 family, is expressed in numerous types of tumors such as breast cancer, prostate cancer, lung cancer, colorectal cancer, hepatocellular carcinoma, glioblastoma and several others. There is convincing evidence to show that miR‑503 functions as a tumor suppressor gene through its effects on target genes that regulate cell proliferation, migration, and invasion in tumor cells. In this current assessment, we discuss the biology and tumor suppressor role of miR‑503 in different cancers and elaborate on its mechanism of action.
    Matched MeSH terms: MicroRNAs/genetics*
  20. Fulltext MicroRNA-6744-5p promotes anoikis in breast cancer and directly targets NAT1 enzyme
    Malagobadan S, Ho CS, Nagoor NH
    Cancer Biol Med, 2020 Feb 15;17(1):101-111.
    PMID: 32296579 DOI: 10.20892/j.issn.2095-3941.2019.0010
    Objective: Anoikis is apoptosis that is induced when cells detach from the extracellular matrix and neighboring cells. As anoikis serves as a regulatory barrier, cancer cells often acquire resistance towards anoikis during tumorigenesis to become metastatic. MicroRNAs (miRNAs) are short strand RNA molecules that regulate genes post-transcriptionally by binding to mRNAs and reducing the expression of its target genes. This study aimed to elucidate the role of a novel miRNA, miR-6744-5p, in regulating anoikis in breast cancer and identify its target gene. Methods: An anoikis resistant variant of the luminal A type breast cancer MCF-7 cell line (MCF-7-AR) was generated by selecting and amplifying surviving cells after repeated exposure to growth in suspension. MiRNA microarray analysis identified a list of dysregulated miRNAs from which miR-6744-5p was chosen for overexpression and knockdown studies in MCF-7. Additionally, the miRNA was also overexpressed in a triple-negative breast cancer cell line, MDA-MB-231, to evaluate its ability to impair the metastatic potential of breast cancer cells. Results: This study showed that overexpression and knockdown of miR-6744-5p in MCF-7 increased and decreased anoikis sensitivity, respectively. Similarly, overexpression of miR-6744-5p in MDA-MB-231 increased anoikis and also decreased tumor cell invasion in vitro and in vivo. Furthermore, NAT1 enzyme was identified and validated as the direct target of miR-6744-5p. Conclusions: This study has proven the ability of miR-6744-5p to increase anoikis sensitivity in both luminal A and triple negative breast cancer cell lines, highlighting its therapeutic potential in treating breast cancer.
    Matched MeSH terms: MicroRNAs/genetics
Related Terms
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links