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Bryant CJ, McCool MA, Rosado González G, Abriola L, Surovtseva Y, Baserga S. Discovery of novel microRNA mimic repressors of ribosome biogenesis. Nucleic Acids Res 2024; 52:1988-2011. [PMID: 38197221 PMCID: PMC10899765 DOI: 10.1093/nar/gkad1235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 12/03/2023] [Accepted: 12/16/2023] [Indexed: 01/11/2024] Open
Abstract
While microRNAs and other non-coding RNAs are the next frontier of novel regulators of mammalian ribosome biogenesis (RB), a systematic exploration of microRNA-mediated RB regulation has not yet been undertaken. We carried out a high-content screen in MCF10A cells for changes in nucleolar number using a library of 2603 mature human microRNA mimics. Following a secondary screen for nucleolar rRNA biogenesis inhibition, we identified 72 novel microRNA negative regulators of RB after stringent hit calling. Hits included 27 well-conserved microRNAs present in MirGeneDB, and were enriched for mRNA targets encoding proteins with nucleolar localization or functions in cell cycle regulation. Rigorous selection and validation of a subset of 15 microRNA hits unexpectedly revealed that most of them caused dysregulated pre-rRNA processing, elucidating a novel role for microRNAs in RB regulation. Almost all hits impaired global protein synthesis and upregulated CDKN1A (p21) levels, while causing diverse effects on RNA Polymerase 1 (RNAP1) transcription and TP53 protein levels. We provide evidence that the MIR-28 siblings, hsa-miR-28-5p and hsa-miR-708-5p, potently target the ribosomal protein mRNA RPS28 via tandem primate-specific 3' UTR binding sites, causing a severe pre-18S pre-rRNA processing defect. Our work illuminates novel microRNA attenuators of RB, forging a promising new path for microRNA mimic chemotherapeutics.
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Affiliation(s)
- Carson J Bryant
- Department of Molecular Biophysics and Biochemistry, Yale School of Medicine, New Haven, CT, 06520, USA
| | - Mason A McCool
- Department of Molecular Biophysics and Biochemistry, Yale School of Medicine, New Haven, CT, 06520, USA
| | | | - Laura Abriola
- Yale Center for Molecular Discovery, Yale University, West Haven, CT, 06516, USA
| | - Yulia V Surovtseva
- Yale Center for Molecular Discovery, Yale University, West Haven, CT, 06516, USA
| | - Susan J Baserga
- Department of Molecular Biophysics and Biochemistry, Yale School of Medicine, New Haven, CT, 06520, USA
- Department of Genetics, Yale School of Medicine, New Haven, CT, 06520, USA
- Department of Therapeutic Radiology, Yale School of Medicine, New Haven, CT, 06520, USA
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2
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Böğürcü-Seidel N, Ritschel N, Acker T, Németh A. Beyond ribosome biogenesis: noncoding nucleolar RNAs in physiology and tumor biology. Nucleus 2023; 14:2274655. [PMID: 37906621 PMCID: PMC10730139 DOI: 10.1080/19491034.2023.2274655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 10/19/2023] [Indexed: 11/02/2023] Open
Abstract
The nucleolus, the largest subcompartment of the nucleus, stands out from the nucleoplasm due to its exceptionally high local RNA and low DNA concentrations. Within this central hub of nuclear RNA metabolism, ribosome biogenesis is the most prominent ribonucleoprotein (RNP) biogenesis process, critically determining the structure and function of the nucleolus. However, recent studies have shed light on other roles of the nucleolus, exploring the interplay with various noncoding RNAs that are not directly involved in ribosome synthesis. This review focuses on this intriguing topic and summarizes the techniques to study and the latest findings on nucleolar long noncoding RNAs (lncRNAs) as well as microRNAs (miRNAs) in the context of nucleolus biology beyond ribosome biogenesis. We particularly focus on the multifaceted roles of the nucleolus and noncoding RNAs in physiology and tumor biology.
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Affiliation(s)
| | - Nadja Ritschel
- Institute of Neuropathology, Justus Liebig University Giessen, Giessen, Germany
| | - Till Acker
- Institute of Neuropathology, Justus Liebig University Giessen, Giessen, Germany
| | - Attila Németh
- Institute of Neuropathology, Justus Liebig University Giessen, Giessen, Germany
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3
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Kaeffer B. Human Breast Milk miRNAs: Their Diversity and Potential for Preventive Strategies in Nutritional Therapy. Int J Mol Sci 2023; 24:16106. [PMID: 38003296 PMCID: PMC10671413 DOI: 10.3390/ijms242216106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 11/02/2023] [Accepted: 11/06/2023] [Indexed: 11/26/2023] Open
Abstract
The endogenous miRNAs of breast milk are the products of more than 1000 nonprotein-coding genes, giving rise to mature small regulatory molecules of 19-25 nucleotides. They are incorporated in macromolecular complexes, loaded on Argonaute proteins, sequestrated in exosomes and lipid complexes, or present in exfoliated cells of epithelial, endothelial, or immune origins. Their expression is dependent on the stage of lactation; however, their detection depends on progress in RNA sequencing and the reappraisal of the definition of small RNAs. Some miRNAs from plants are detected in breast milk, opening the possibility of the stimulation of immune cells from the allergy repertoire. Each miRNA harbors a seeding sequence, which targets mRNAs, gene promoters, or long noncoding RNAs. Their activities depend on their bioavailability. Efficient doses of miRNAs are estimated to be roughly 100 molecules in the cytoplasm of target cells from in vitro and in vivo experiments. Each miRNA is included in networks of stimulation/inhibition/sequestration, driving the expression of cellular phenotypes. Three types of stress applied during lactation to manipulate miRNA supply were explored using rodent offspring: a foster mother, a cafeteria diet, and early weaning. This review presents the main mature miRNAs described from current mothers' cohorts and their bioavailability in experimental models as well as studies assessing the potential of miR-26 or miR-320 miRNA families to alter offspring phenotypes.
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Affiliation(s)
- Bertrand Kaeffer
- Nantes Université, INRAE, UMR 1280, PhAN, F-44000 Nantes, France
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4
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Bryant CJ, McCool MA, Rosado-González GT, Abriola L, Surovtseva YV, Baserga SJ. Discovery of novel microRNA mimic repressors of ribosome biogenesis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.17.526327. [PMID: 36824951 PMCID: PMC9949135 DOI: 10.1101/2023.02.17.526327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
While microRNAs and other non-coding RNAs are the next frontier of novel regulators of mammalian ribosome biogenesis (RB), a systematic exploration of microRNA-mediated RB regulation has not yet been undertaken. We carried out a high-content screen in MCF10A cells for changes in nucleolar number using a library of 2,603 mature human microRNA mimics. Following a secondary screen for nucleolar rRNA biogenesis inhibition, we identified 72 novel microRNA negative regulators of RB after stringent hit calling. Hits included 27 well-conserved microRNAs present in MirGeneDB, and were enriched for mRNA targets encoding proteins with nucleolar localization or functions in cell cycle regulation. Rigorous selection and validation of a subset of 15 microRNA hits unexpectedly revealed that most of them caused dysregulated pre-rRNA processing, elucidating a novel role for microRNAs in RB regulation. Almost all hits impaired global protein synthesis and upregulated CDKN1A ( p21 ) levels, while causing diverse effects on RNA Polymerase 1 (RNAP1) transcription and TP53 protein levels. We discovered that the MIR-28 siblings, hsa-miR-28-5p and hsa-miR-708-5p, directly and potently target the ribosomal protein mRNA RPS28 via tandem primate-specific 3' UTR binding sites, causing a severe pre-18S pre-rRNA processing defect. Our work illuminates novel microRNA attenuators of RB, forging a promising new path for microRNA mimic chemotherapeutics.
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5
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Nalavade R, Singh M. Intracellular Compartmentalization: A Key Determinant of MicroRNA Functions. Microrna 2023; 12:114-130. [PMID: 37638608 DOI: 10.2174/2211536612666230330184006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 12/26/2022] [Accepted: 01/19/2023] [Indexed: 08/29/2023]
Abstract
Being an integral part of the eukaryotic transcriptome, miRNAs are regarded as vital regulators of diverse developmental and physiological processes. Clearly, miRNA activity is kept in check by various regulatory mechanisms that control their biogenesis and decay pathways. With the increasing technical depth of RNA profiling technologies, novel insights have unravelled the spatial diversity exhibited by miRNAs inside a cell. Compartmentalization of miRNAs adds complexity to the regulatory circuits of miRNA expression, thereby providing superior control over the miRNA function. This review provides a bird's eye view of miRNAs expressed in different subcellular locations, thus affecting the gene regulatory pathways therein. Occurrence of miRNAs in diverse intracellular locales also reveals various unconventional roles played by miRNAs in different cellular organelles and expands the scope of miRNA functions beyond their traditionally known repressive activities.
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Affiliation(s)
- Rohit Nalavade
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | - Mohini Singh
- Department of Life Sciences, Sharda School of Basic Sciences and Research, Sharda University, Greater Noida, India
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6
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Challenging Cellular Homeostasis: Spatial and Temporal Regulation of miRNAs. Int J Mol Sci 2022; 23:ijms232416152. [PMID: 36555797 PMCID: PMC9787707 DOI: 10.3390/ijms232416152] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 12/11/2022] [Accepted: 12/15/2022] [Indexed: 12/23/2022] Open
Abstract
Mature microRNAs (miRNAs) are single-stranded non-coding RNA (ncRNA) molecules that act in post-transcriptional regulation in animals and plants. A mature miRNA is the end product of consecutive, highly regulated processing steps of the primary miRNA transcript. Following base-paring of the mature miRNA with its mRNA target, translation is inhibited, and the targeted mRNA is degraded. There are hundreds of miRNAs in each cell that work together to regulate cellular key processes, including development, differentiation, cell cycle, apoptosis, inflammation, viral infection, and more. In this review, we present an overlooked layer of cellular regulation that addresses cell dynamics affecting miRNA accessibility. We discuss the regulation of miRNA local storage and translocation among cell compartments. The local amounts of the miRNAs and their targets dictate their actual availability, which determines the ability to fine-tune cell responses to abrupt or chronic changes. We emphasize that changes in miRNA storage and compactization occur under induced stress and changing conditions. Furthermore, we demonstrate shared principles on cell physiology, governed by miRNA under oxidative stress, tumorigenesis, viral infection, or synaptic plasticity. The evidence presented in this review article highlights the importance of spatial and temporal miRNA regulation for cell physiology. We argue that limiting the research to mature miRNAs within the cytosol undermines our understanding of the efficacy of miRNAs to regulate cell fate under stress conditions.
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7
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Liu J, Yang T, Huang Z, Chen H, Bai Y. Transcriptional regulation of nuclear miRNAs in tumorigenesis (Review). Int J Mol Med 2022; 50:92. [PMID: 35593304 DOI: 10.3892/ijmm.2022.5148] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Accepted: 04/28/2022] [Indexed: 11/05/2022] Open
Abstract
MicroRNAs (miRNAs/miRs) are a type of endogenous non‑coding small RNA that regulates gene expression. miRNAs regulate gene expression at the post‑transcriptional level by targeting the 3'‑untranslated region (3'UTR) of cytoplasmic messenger RNAs (mRNAs). Recent research has confirmed the presence of mature miRNAs in the nucleus, which bind nascent RNA transcripts, gene promoter or enhancer regions, and regulate gene expression via epigenetic pathways. Some miRNAs have been shown to function as oncogenes or tumor suppressor genes by modulating molecular pathways involved in human cancers. Notably, a novel molecular mechanism underlying the dysregulation of miRNA expression in cancer has recently been discovered, indicating that miRNAs may be involved in tumorigenesis via a nuclear function that influences gene transcription and epigenetic states, elucidating their potential therapeutic implications. The present review article discusses the import of nuclear miRNAs, nucleus‑cytoplasm transport mechanisms and the nuclear functions of miRNAs in cancer. In addition, some software tools for predicting miRNA binding sites are also discussed. Nuclear miRNAs supplement miRNA regulatory networks in cancer as a non‑canonical aspect of miRNA action. Further research into this aspect may be critical for understanding the role of nuclear miRNAs in the development of human cancers.
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Affiliation(s)
- Junjie Liu
- School of Life Science and Engineering, Foshan University, Foshan, Guangdong 528225, P.R. China
| | - Tianhao Yang
- School of Life Science and Engineering, Foshan University, Foshan, Guangdong 528225, P.R. China
| | - Zishen Huang
- School of Life Science and Engineering, Foshan University, Foshan, Guangdong 528225, P.R. China
| | - Huifang Chen
- School of Life Science and Engineering, Foshan University, Foshan, Guangdong 528225, P.R. China
| | - Yinshan Bai
- School of Life Science and Engineering, Foshan University, Foshan, Guangdong 528225, P.R. China
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8
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Popławski P, Bogusławska J, Hanusek K, Piekiełko-Witkowska A. Nucleolar Proteins and Non-Coding RNAs: Roles in Renal Cancer. Int J Mol Sci 2021; 22:ijms222313126. [PMID: 34884928 PMCID: PMC8658237 DOI: 10.3390/ijms222313126] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 11/29/2021] [Accepted: 12/02/2021] [Indexed: 02/07/2023] Open
Abstract
Renal cell cancer is the most frequent kidney malignancy. Most RCC cases are classified as clear cell renal cell carcinoma (ccRCC), characterized by high aggressiveness and poor prognosis for patients. ccRCC aggressiveness is defined by classification systems based on changes in morphology of nucleoli, the membraneless substructures of nuclei. The latter act as the sites of ribosome biogenesis as well as the hubs that trap and immobilize proteins, preventing their action in other cellular compartments. Thereby, nucleoli control cellular functioning and homeostasis. Nucleoli are also the sites of activity of multiple noncoding RNAs, including snoRNAs, IGS RNA, and miRNAs. Recent years have brought several remarkable discoveries regarding the role of nucleolar non-coding RNAs, in particular snoRNAs, in ccRCC. The expression of snoRNAs is largely dysregulated in ccRCC tumors. snoRNAs, such as SNHG1, SNHG4 and SNHG12, act as miRNA sponges, leading to aberrant expression of oncogenes and tumor suppressors, and directly contributing to ccRCC development and progression. snoRNAs can also act without affecting miRNA functioning, by altering the expression of key oncogenic proteins such as HIF1A. snoRNAs are also potentially useful biomarkers of ccRCC progression. Here, we comprehensively discuss the role of nucleolar proteins and non-coding RNAs in ccRCC.
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Hayek H, Kosmider B, Bahmed K. The role of miRNAs in alveolar epithelial cells in emphysema. Biomed Pharmacother 2021; 143:112216. [PMID: 34649347 PMCID: PMC9275516 DOI: 10.1016/j.biopha.2021.112216] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 09/13/2021] [Accepted: 09/15/2021] [Indexed: 02/07/2023] Open
Abstract
Chronic obstructive pulmonary disease (COPD) is an inflammatory lung disease becoming one of the leading causes of mortality and morbidity globally. The significant risk factors for COPD are exposure to harmful particles such as cigarette smoke, biomass smoke, and air pollution. Pulmonary emphysema belongs to COPD and is characterized by a unique alveolar destruction pattern resulting in marked airspace enlargement. Alveolar type II (ATII) cells have stem cell potential; they proliferate and differentiate to alveolar type I cells to restore the epithelium after damage. Oxidative stress causes premature cell senescence that can contribute to emphysema development. MiRNAs regulate gene expression, are essential for maintaining ATII cell homeostasis, and their dysregulation contributes to this disease development. They also serve as biomarkers of lung diseases and potential therapeutics. In this review, we summarize recent findings on miRNAs’ role in alveolar epithelial cells in emphysema.
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Affiliation(s)
- Hassan Hayek
- Department of Microbiology, Immunology, and Inflammation, Temple University, Philadelphia, PA 19140, USA; Center for Inflammation and Lung Research, Temple University, Philadelphia, PA 19140, USA
| | - Beata Kosmider
- Department of Microbiology, Immunology, and Inflammation, Temple University, Philadelphia, PA 19140, USA; Center for Inflammation and Lung Research, Temple University, Philadelphia, PA 19140, USA; Department of Biomedical Education and Data Science, Temple University, Philadelphia, PA 19140, USA
| | - Karim Bahmed
- Center for Inflammation and Lung Research, Temple University, Philadelphia, PA 19140, USA; Department of Thoracic Medicine and Surgery, Temple University, Philadelphia, PA 19140, USA.
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10
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Noncoding RNAs link metabolic reprogramming to immune microenvironment in cancers. J Hematol Oncol 2021; 14:169. [PMID: 34654454 PMCID: PMC8518176 DOI: 10.1186/s13045-021-01179-y] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Accepted: 09/27/2021] [Indexed: 02/08/2023] Open
Abstract
Altered metabolic patterns in tumor cells not only meet their own growth requirements but also shape an immunosuppressive microenvironment through multiple mechanisms. Noncoding RNAs constitute approximately 60% of the transcriptional output of human cells and have been shown to regulate numerous cellular processes under developmental and pathological conditions. Given their extensive action mechanisms based on motif recognition patterns, noncoding RNAs may serve as hinges bridging metabolic activity and immune responses. Indeed, recent studies have shown that microRNAs, long noncoding RNAs and circRNAs are widely involved in tumor metabolic rewiring, immune cell infiltration and function. Hence, we summarized existing knowledge of the role of noncoding RNAs in the remodeling of tumor metabolism and the immune microenvironment, and notably, we established the TIMELnc manual, which is a free and public manual for researchers to identify pivotal lncRNAs that are simultaneously correlated with tumor metabolism and immune cell infiltration based on a bioinformatic approach.
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11
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MicroRNA 195-5p Targets Foxo3 Promoter Region to Regulate Its Expression in Granulosa Cells. Int J Mol Sci 2021; 22:ijms22136721. [PMID: 34201585 PMCID: PMC8267755 DOI: 10.3390/ijms22136721] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Revised: 05/21/2021] [Accepted: 05/24/2021] [Indexed: 12/24/2022] Open
Abstract
Forkhead box O3 (Foxo3) is a member of the FOXO subfamily within the forkhead box (FOX) family, which has been shown to be essential for ovarian follicular development and maturation. Previous studies have shown the abundant expression of miR-195-5p in the nuclei of porcine granulosa cells (GCs), suggesting its potential role during ovarian follicle growth. In this study, a conditional immortalized porcine granulosa cell (CIPGC) line was used to determine whether the expression of Foxo3 could be regulated by the nuclear-enriched miR-195-5p. Through silico target prediction, we identified a potential binding site of miR-195-5p within the Foxo3 promoter. The over-expression of miR-195-5p increased Foxo3 expression at both mRNA and protein levels, while the knockdown of miR-195-5p decreased the expression of Foxo3. Furthermore, driven by the Foxo3 promoter, luciferase reporter activity was increased in response to miR-195-5p, while the mutation of the miR-195-5p binding site in the promoter region abolished this effect. In addition, the siRNA knockdown of Argonaute (AGO) 2, but not AGO1, significantly decreased Foxo3 transcript level. However, miR-195-5p failed to upregulate Foxo3 expression when AGO2 was knocked down. Moreover, chromatin immunoprecipitation (CHIP) assay showed that anti-AGO2 antibody pulled down both AGO2 and the Foxo3 promoter sequence, suggesting that AGO2 may be required for miR-195-5p to regulate Foxo3 expression in the nucleus. Additionally, Foxo3 expression was significantly increased by valproic acid (VPA), the inhibitor of deacetylase, as well as by methyltransferase inhibitor BIX-01294, indicating the involvement of histone modification. These effects were further enhanced in the presence of miR-195-5p and were decreased when miR-195-5p was knocked down. Overall, our results suggest that nuclear-enriched miR-195-5p regulates Foxo3 expression, which may be associated with AGO2 recruitment, as well as histone demethylation and acetylation in ovarian granulosa cells.
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12
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MicroRNA regulation of prefrontal cortex development and psychiatric risk in adolescence. Semin Cell Dev Biol 2021; 118:83-91. [PMID: 33933350 DOI: 10.1016/j.semcdb.2021.04.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 04/08/2021] [Accepted: 04/09/2021] [Indexed: 12/28/2022]
Abstract
In this review, we examine the role of microRNAs in the development of the prefrontal cortex (PFC) in adolescence and in individual differences in vulnerability to mental illness. We describe results from clinical and preclinical research indicating that adolescence coincides with drastic changes in local microRNA expression, including microRNAs that control gene networks involved in PFC and cognitive refinement. We highlight that altered levels of microRNAs in the PFC are associated with psychopathologies of adolescent onset, notably depression and schizophrenia. We show that microRNAs can be measured non-invasively in peripheral samples and could serve as longitudinal physiological readouts of brain expression and psychiatric risk in youth.
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13
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MicroRNAs and long non-coding RNAs as novel regulators of ribosome biogenesis. Biochem Soc Trans 2021; 48:595-612. [PMID: 32267487 PMCID: PMC7200637 DOI: 10.1042/bst20190854] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 03/12/2020] [Accepted: 03/16/2020] [Indexed: 12/14/2022]
Abstract
Ribosome biogenesis is the fine-tuned, essential process that generates mature ribosomal subunits and ultimately enables all protein synthesis within a cell. Novel regulators of ribosome biogenesis continue to be discovered in higher eukaryotes. While many known regulatory factors are proteins or small nucleolar ribonucleoproteins, microRNAs (miRNAs), and long non-coding RNAs (lncRNAs) are emerging as a novel modulatory layer controlling ribosome production. Here, we summarize work uncovering non-coding RNAs (ncRNAs) as novel regulators of ribosome biogenesis and highlight their links to diseases of defective ribosome biogenesis. It is still unclear how many miRNAs or lncRNAs are involved in phenotypic or pathological disease outcomes caused by impaired ribosome production, as in the ribosomopathies, or by increased ribosome production, as in cancer. In time, we hypothesize that many more ncRNA regulators of ribosome biogenesis will be discovered, which will be followed by an effort to establish connections between disease pathologies and the molecular mechanisms of this additional layer of ribosome biogenesis control.
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14
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Odame E, Chen Y, Zheng S, Dai D, Kyei B, Zhan S, Cao J, Guo J, Zhong T, Wang L, Li L, Zhang H. Enhancer RNAs: transcriptional regulators and workmates of NamiRNAs in myogenesis. Cell Mol Biol Lett 2021; 26:4. [PMID: 33568070 PMCID: PMC7877072 DOI: 10.1186/s11658-021-00248-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 02/02/2021] [Indexed: 02/08/2023] Open
Abstract
miRNAs are well known to be gene repressors. A newly identified class of miRNAs termed nuclear activating miRNAs (NamiRNAs), transcribed from miRNA loci that exhibit enhancer features, promote gene expression via binding to the promoter and enhancer marker regions of the target genes. Meanwhile, activated enhancers produce endogenous non-coding RNAs (named enhancer RNAs, eRNAs) to activate gene expression. During chromatin looping, transcribed eRNAs interact with NamiRNAs through enhancer-promoter interaction to perform similar functions. Here, we review the functional differences and similarities between eRNAs and NamiRNAs in myogenesis and disease. We also propose models demonstrating their mutual mechanism and function. We conclude that eRNAs are active molecules, transcriptional regulators, and partners of NamiRNAs, rather than mere RNAs produced during enhancer activation.
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Affiliation(s)
- Emmanuel Odame
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, 611130, China
| | - Yuan Chen
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, 611130, China
| | - Shuailong Zheng
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, 611130, China
| | - Dinghui Dai
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, 611130, China
| | - Bismark Kyei
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, 611130, China
| | - Siyuan Zhan
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, 611130, China
| | - Jiaxue Cao
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, 611130, China
| | - Jiazhong Guo
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, 611130, China
| | - Tao Zhong
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, 611130, China
| | - Linjie Wang
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, 611130, China
| | - Li Li
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, 611130, China.
| | - Hongping Zhang
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, 611130, China.
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15
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Barlak N, Capik O, Kilic A, Sanli F, Aytatli A, Yazici A, Karatas EA, Ortucu S, Karatas OF. MicroRNA-145 transcriptionally regulates Semaphorin 3A expression in prostate cancer cells. Cell Biol Int 2021; 45:1082-1090. [PMID: 33501702 DOI: 10.1002/cbin.11554] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 01/24/2021] [Indexed: 12/25/2022]
Abstract
Prostate cancer (PCa) is one of the most prevalent cancer types among males. Differential expression of microRNAs is associated with various cancers including PCa. Although mature microRNAs are preferentially located in the cytoplasm, several studies identified mature human microRNAs in purified nuclei and miR-145 has been found to be predominantly expressed in the nuclei of benign tissues compared to tumor lesions. However, the nuclear functions of miR-145 are yet limited. Here, we aimed at investigating the inductive role of miR-145 on the expression of Semaphorin 3A (SEMA3A) in PCa cell lines. To study the regulatory potential of miR-145 in the transcriptional level in PCa, we overexpressed miR-145 in PC3 and DU145 cells, and confirmed its upregulation by quantitative-real-time-PCR. Then we investigated the tumor suppressor potential of miR-145 upon inducing SEMA3A expression using cell viability assay, western blot analysis, Chromatin Immunoprecipitation assay and luciferase reporter assay. Our results revealed that p53, miR-145, and SEMA3A expressions are significantly downregulated in PC3 and DU145 cells compared to nontumorigenic prostate epithelial PNT1a cells. miR-145 overexpression in PCa cells induced the expression of SEMA3A at both messenger RNA and protein levels. Furthermore, increased miR-145 expression enriched RNA Pol-II antibody on the promoter of SEMA3A and induced luciferase activity controlled by SEMA3A promoter. In this study, we showed that the functions of miR-145 are not limited to gene silencing, and found that it may lead to changes in gene expression in the transcriptional level.
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Affiliation(s)
- Neslisah Barlak
- Department of Molecular Biology and Genetics, Erzurum Technical University, Erzurum, Turkey.,Molecular Cancer Biology Laboratory, High Technology Application and Research Center, Erzurum Technical University, Erzurum, Turkey
| | - Ozel Capik
- Department of Molecular Biology and Genetics, Erzurum Technical University, Erzurum, Turkey.,Molecular Cancer Biology Laboratory, High Technology Application and Research Center, Erzurum Technical University, Erzurum, Turkey
| | - Ahsen Kilic
- Department of Molecular Biology and Genetics, Erzurum Technical University, Erzurum, Turkey.,Molecular Cancer Biology Laboratory, High Technology Application and Research Center, Erzurum Technical University, Erzurum, Turkey
| | - Fatma Sanli
- Department of Molecular Biology and Genetics, Erzurum Technical University, Erzurum, Turkey.,Molecular Cancer Biology Laboratory, High Technology Application and Research Center, Erzurum Technical University, Erzurum, Turkey
| | - Abdulmelik Aytatli
- Department of Molecular Biology and Genetics, Erzurum Technical University, Erzurum, Turkey.,Molecular Cancer Biology Laboratory, High Technology Application and Research Center, Erzurum Technical University, Erzurum, Turkey
| | - Aysenur Yazici
- Department of Molecular Biology and Genetics, Erzurum Technical University, Erzurum, Turkey.,Molecular Cancer Biology Laboratory, High Technology Application and Research Center, Erzurum Technical University, Erzurum, Turkey
| | - Elanur Aydin Karatas
- Department of Molecular Biology and Genetics, Erzurum Technical University, Erzurum, Turkey.,Molecular Cancer Biology Laboratory, High Technology Application and Research Center, Erzurum Technical University, Erzurum, Turkey
| | - Serkan Ortucu
- Department of Molecular Biology and Genetics, Erzurum Technical University, Erzurum, Turkey.,Molecular Cancer Biology Laboratory, High Technology Application and Research Center, Erzurum Technical University, Erzurum, Turkey
| | - Omer Faruk Karatas
- Department of Molecular Biology and Genetics, Erzurum Technical University, Erzurum, Turkey.,Molecular Cancer Biology Laboratory, High Technology Application and Research Center, Erzurum Technical University, Erzurum, Turkey
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16
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Annese T, Tamma R, De Giorgis M, Ribatti D. microRNAs Biogenesis, Functions and Role in Tumor Angiogenesis. Front Oncol 2020; 10:581007. [PMID: 33330058 PMCID: PMC7729128 DOI: 10.3389/fonc.2020.581007] [Citation(s) in RCA: 100] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 10/27/2020] [Indexed: 12/19/2022] Open
Abstract
microRNAs (miRNAs) are small non-coding RNA molecules, evolutionary conserved. They target more than one mRNAs, thus influencing multiple molecular pathways, but also mRNAs may bind to a variety of miRNAs, either simultaneously or in a context-dependent manner. miRNAs biogenesis, including miRNA transcription, processing by Drosha and Dicer, transportation, RISC biding, and miRNA decay, are finely controlled in space and time. miRNAs are critical regulators in various biological processes, such as differentiation, proliferation, apoptosis, and development in both health and disease. Their dysregulation is involved in tumor initiation and progression. In tumors, they can act as onco-miRNAs or oncosuppressor-miRNA participating in distinct cellular pathways, and the same miRNA can perform both activities depending on the context. In tumor progression, the angiogenic switch is fundamental. miRNAs derived from tumor cells, endothelial cells, and cells of the surrounding microenvironment regulate tumor angiogenesis, acting as pro-angiomiR or anti-angiomiR. In this review, we described miRNA biogenesis and function, and we update the non-classical aspects of them. The most recent role in the nucleus, as transcriptional gene regulators and the different mechanisms by which they could be dysregulated, in tumor initiation and progression, are treated. In particular, we describe the role of miRNAs in sprouting angiogenesis, vessel co-option, and vasculogenic mimicry. The role of miRNAs in lymphoma angiogenesis is also discussed despite the scarcity of data. The information presented in this review reveals the need to do much more to discover the complete miRNA network regulating angiogenesis, not only using high-throughput computational analysis approaches but also morphological ones.
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Affiliation(s)
- Tiziana Annese
- Department of Basic Medical Sciences, Neurosciences and Sensory Organs, Section of Human Anatomy and Histology, University of Bari Medical School, Bari, Italy
| | - Roberto Tamma
- Department of Basic Medical Sciences, Neurosciences and Sensory Organs, Section of Human Anatomy and Histology, University of Bari Medical School, Bari, Italy
| | - Michelina De Giorgis
- Department of Basic Medical Sciences, Neurosciences and Sensory Organs, Section of Human Anatomy and Histology, University of Bari Medical School, Bari, Italy
| | - Domenico Ribatti
- Department of Basic Medical Sciences, Neurosciences and Sensory Organs, Section of Human Anatomy and Histology, University of Bari Medical School, Bari, Italy
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17
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miRNALoc: predicting miRNA subcellular localizations based on principal component scores of physico-chemical properties and pseudo compositions of di-nucleotides. Sci Rep 2020; 10:14557. [PMID: 32884018 PMCID: PMC7471944 DOI: 10.1038/s41598-020-71381-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 07/07/2020] [Indexed: 12/20/2022] Open
Abstract
MicroRNAs (miRNAs) are one kind of non-coding RNA, play vital role in regulating several physiological and developmental processes. Subcellular localization of miRNAs and their abundance in the native cell are central for maintaining physiological homeostasis. Besides, RNA silencing activity of miRNAs is also influenced by their localization and stability. Thus, development of computational method for subcellular localization prediction of miRNAs is desired. In this work, we have proposed a computational method for predicting subcellular localizations of miRNAs based on principal component scores of thermodynamic, structural properties and pseudo compositions of di-nucleotides. Prediction accuracy was analyzed following fivefold cross validation, where ~ 63–71% of AUC-ROC and ~ 69–76% of AUC-PR were observed. While evaluated with independent test set, > 50% localizations were found to be correctly predicted. Besides, the developed computational model achieved higher accuracy than the existing methods. A user-friendly prediction server “miRNALoc” is freely accessible at https://cabgrid.res.in:8080/mirnaloc/, by which the user can predict localizations of miRNAs.
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18
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MicroRNAs as Guardians of the Prostate: Those Who Stand before Cancer. What Do We Really Know about the Role of microRNAs in Prostate Biology? Int J Mol Sci 2020; 21:ijms21134796. [PMID: 32645914 PMCID: PMC7370012 DOI: 10.3390/ijms21134796] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 06/29/2020] [Accepted: 07/02/2020] [Indexed: 12/17/2022] Open
Abstract
Prostate cancer is the second leading cause of cancer-related deaths of men in the Western world. Despite recent advancement in genomics, transcriptomics and proteomics to understand prostate cancer biology and disease progression, castration resistant metastatic prostate cancer remains a major clinical challenge and often becomes incurable. MicroRNAs (miRNAs), about 22-nucleotide-long non-coding RNAs, are a group of regulatory molecules that mainly work through post-transcriptional gene silencing via translational repression. Expression analysis studies have revealed that miRNAs are aberrantly expressed in cancers and have been recognized as regulators of prostate cancer progression. In this critical review, we provide an analysis of reported miRNA functions and conflicting studies as they relate to expression levels of specific miRNAs and prostate cancer progression; oncogenic and/or tumor suppressor roles; androgen receptor signaling; epithelial plasticity; and the current status of diagnostic and therapeutic applications. This review focuses on select miRNAs, highly expressed in normal and cancer tissue, to emphasize the current obstacles faced in utilizing miRNA data for significant impacts on prostate cancer therapeutics.
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19
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Abstract
MicroRNAs (miRNAs) are 22-nucleotide RNA sequences that regulate up to 60% of the mammalian transcriptome. Although canonical miRNA-induced silencing complex-mediated messenger RNA degradation occurs in the cytoplasm, miRNAs have been described in other subcellular compartments with potentially novel functions. Currently, there are limited methodologies for visualizing RNA locations within cells to elucidate mechanisms and pathways of miRNA biogenesis, transport, and function. Here, we describe a simple and rapid miRNA in situ hybridization method that can be combined with standard immunofluorescence procedures for subcellular localization of mature and precursor miRNAs.
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20
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Linhares-Lacerda L, Temerozo JR, Ribeiro-Alves M, Azevedo EP, Mojoli A, Nascimento MTC, Silva-Oliveira G, Savino W, Foguel D, Bou-Habib DC, Saraiva EM. Neutrophil extracellular trap-enriched supernatants carry microRNAs able to modulate TNF-α production by macrophages. Sci Rep 2020; 10:2715. [PMID: 32066757 PMCID: PMC7026108 DOI: 10.1038/s41598-020-59486-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 01/27/2020] [Indexed: 01/03/2023] Open
Abstract
Neutrophil extracellular traps (NETs) emerge from the cell as a DNA scaffold associated with cytoplasmic and granular proteins, able to immobilize and kill pathogens. This association occurs following nuclear and granular membrane disintegration, allowing contact with the decondensed chromatin. Thus, it is reasonable to speculate that the DNA can also mix with miRNAs and carry them in NETs. Here, we report for the first time the presence of the miRNA carriers associated with NETs and miRNAs present in NET-enriched supernatants (NET-miRs), thus adding a novel class of molecules and new proteins that can be released and transported in the NET platform. We observed that the majority of NET-miRs were common to all four stimuli used (PMA, interleukin-8, amyloid fibrils and Leishmania), and that miRNA-142-3p carried by NETs down-modulates protein kinase Cα and regulates TNF-α production in macrophages upon NET interaction with these cells. Our findings unveil a novel role for NETs in the cell communication processes, allowing the conveyance of miRNA from neutrophils to neighboring cells.
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Affiliation(s)
- Leandra Linhares-Lacerda
- Laboratory of Immunobiology of Leishmaniasis, Department of Immunology, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
| | - Jairo Ramos Temerozo
- Laboratory on Thymus Research, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.,National Institute of Science and Technology on Neuroimmunomodulation, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Marcelo Ribeiro-Alves
- HIV/AIDS Clinical Research Center, Evandro Chagas National Institute of Infectology, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Estefania P Azevedo
- Instituto de Bioquimica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil, Brazil
| | - Andres Mojoli
- Laboratory on Thymus Research, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Michelle T C Nascimento
- Laboratory of Immunobiology of Leishmaniasis, Department of Immunology, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.,Instituto de Bioquimica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil, Brazil
| | - Gustavo Silva-Oliveira
- Laboratory of Immunobiology of Leishmaniasis, Department of Immunology, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Wilson Savino
- Laboratory on Thymus Research, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.,National Institute of Science and Technology on Neuroimmunomodulation, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Debora Foguel
- Instituto de Bioquimica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil, Brazil
| | - Dumith Chequer Bou-Habib
- Laboratory on Thymus Research, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.,National Institute of Science and Technology on Neuroimmunomodulation, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Elvira M Saraiva
- Laboratory of Immunobiology of Leishmaniasis, Department of Immunology, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
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21
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Eckstein M, Sailer V, Nielsen BS, Wittenberg T, Wiesmann V, Lieb V, Nolte E, Hartmann A, Kristiansen G, Wernert N, Wullich B, Taubert H, Wach S. Co-staining of microRNAs and their target proteins by miRNA in situ hybridization and immunohistofluorescence on prostate cancer tissue microarrays. J Transl Med 2019; 99:1527-1534. [PMID: 31186527 DOI: 10.1038/s41374-019-0251-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 04/01/2019] [Accepted: 04/01/2019] [Indexed: 01/31/2023] Open
Abstract
The co-expression of miRNAs and their target proteins was studied on tissue microarrays from different prostate cancer (PCa) patients. PCa of primary Gleason pattern 4 (GP4), lymph node metastases of GP4, distant metastases, and normal tissue from the transitional and peripheral zones were co-stained by fluorescent miRNA in situ hybridization (miRisH) and protein immunohistofluorescence (IHF). The miRNAs and corresponding target proteins include the pairs miR-145/ERG, miR-143/uPAR, and miR-375/SEC23A. The fluorescence-stained and scanned tissue microarrays (TMAs) were evaluated by experienced uropathologists. The pair miR-145/ERG showed an exclusive staining for miR-145 in the nuclei of stromal cells, both in tumor and normal tissue, and for ERG in the cytoplasm with/without co-expression in the nucleus of tumor cells. The pair miR-143/uPAR revealed a clear distinction between miR-143 in the nuclei of stromal cells and uPAR staining in the cytoplasm of tumor cells. Metastases (lymph node and distant) however, showed tumor cells with cytoplasmic staining for miR-143/uPAR. In normal tissues, beside the nuclei of the stroma cells, gland cells could also express miR-143 and uPAR in the cytoplasm. miR-375 showed particular staining in the nucleoli of GP4 and metastatic samples, suggesting that nucleoli play a special role in sequestering proteins and miRNAs. Combined miRisH/IHF allows for the study of miRNA expression patterns and their target proteins at the single-cell level.
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Affiliation(s)
- Markus Eckstein
- Institute of Pathology, University Hospital Erlangen, FAU Erlangen-Nürnberg, Erlangen, Germany
| | - Verena Sailer
- Institute of Pathology, University Hospital Bonn, Bonn, Germany.,Department of Pathology and Laboratory Medicine, Weill Cornell Medicine of Cornell University, New York, NY, USA
| | | | | | - Veit Wiesmann
- Fraunhofer Institute for Integrated Circuits IIS, Erlangen, Germany
| | - Verena Lieb
- Department of Urology and Pediatric Urology, University Hospital Erlangen, FAU Erlangen-Nürnberg, Erlangen, Germany
| | - Elke Nolte
- Department of Urology and Pediatric Urology, University Hospital Erlangen, FAU Erlangen-Nürnberg, Erlangen, Germany
| | - Arndt Hartmann
- Institute of Pathology, University Hospital Erlangen, FAU Erlangen-Nürnberg, Erlangen, Germany
| | | | - Nicolas Wernert
- Institute of Pathology, University Hospital Bonn, Bonn, Germany
| | - Bernd Wullich
- Department of Urology and Pediatric Urology, University Hospital Erlangen, FAU Erlangen-Nürnberg, Erlangen, Germany
| | - Helge Taubert
- Department of Urology and Pediatric Urology, University Hospital Erlangen, FAU Erlangen-Nürnberg, Erlangen, Germany.
| | - Sven Wach
- Department of Urology and Pediatric Urology, University Hospital Erlangen, FAU Erlangen-Nürnberg, Erlangen, Germany
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22
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Beuzelin D, Pitard B, Kaeffer B. Oral Delivery of miRNA With Lipidic Aminoglycoside Derivatives in the Breastfed Rat. Front Physiol 2019; 10:1037. [PMID: 31456698 PMCID: PMC6700720 DOI: 10.3389/fphys.2019.01037] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 07/29/2019] [Indexed: 12/16/2022] Open
Abstract
CONTEXT Specific targeting of endogenous miRNAs which are involved in epigenetics, may help understanding homeostasis with therapeutic benefits. We use new biologically inspired vehicles consisting of lipoaminoglycosides to deliver in vivo mir-320-3p, a known human breast milk exosomal miRNA, or its antagomiR. MATERIALS AND METHODS Four lipoaminoglycosides were screened for cytotoxicity and their biophysical properties. 1-h breast-restricted rats received single-oral treatment of either the lipoaminoglycoside Dioleyl-Succinyl Paromomycin (DOSP) complexed with miRNA or antagomiR, or of control medium at the light on (ZeitGeber Time: ZT-0H) or off (ZT-12H). Glycemia, triglycerides, cholesterol, free-fatty acid were assayed at 0, 4, 8, and 12 h post-treatment. In the stomach, small intestine, liver, plasma, adipose tissue, plexus choroid, and cortex, relevant miRNA with precursors and mRNA (polr3d, hspb6, c-myc, stat1, clock, bmal1, per1, npas2, sirt1-6, and cyclinD1) were quantified by q-PCR. Expression of POLR3D and HSPB6 proteins were analyzed in stomach and liver by Western blot. Immunoprecipitations with anti-AGO1 and 2 were performed on nuclear and cytoplasmic fractions of gastric cells along with detection of miRNA-320-3p in nucleoli. Chromatin ImmunoPrecipitation with anti-Trimethyl-histone-3-Lys-4 and Lys-27 detecting the polr3d promoter and miR-320-3p, were performed for all groups. RESULTS Selected DOSP (diameter: 80-200 nm) did not alter gastric extracellular vesicle secretion a few hours after intake. The miR-320-3p was mainly found in gastric or small intestinal cells, reaching the blood and liver in low amount. We have found significant up-regulation of polr3d mRNA (ANOVA, p < 0.0001) at ZT-20H for the miR-320-3p-supplemented group and a higher expression of POLR3D for antagomiR group (ANOVA, p < 0.05). We had a low accumulation of miR-320-3p at ZT-20H in nucleoli, without stat1 evolution. Delivering a high amount of miRNA or antagomiR disrupts RNA-Induced Silencing Complexes in cytoplasm triggering some transfer of extracellular molecules into nuclei with alteration of immune complexes on the polr3d promoter (with a higher amount found in the K4 histone-3-me3 immune complexes at ZT-20H). CONCLUSION Extracellular miRNAs embedded in DOSP have a rapid impact on RNAi and on nuclear chromatin complexes depending on the daily rhythm. An integrative view of the impact of extracellular miRNA on physiology will improve assaying epigenetic manipulations following nutritional stress.
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Affiliation(s)
- Diane Beuzelin
- UMR 1280, NUN, Institut National de la Recherche Agronomique, Nantes, France
| | - Bruno Pitard
- Centre de Recherche en Cancérologie et Immunologie Nantes Angers (CRCINA), Institut National de la Santé et de la Recherche Médicale (INSERM), Université d’Angers, Université de Nantes, Nantes, France
| | - Bertrand Kaeffer
- UMR 1280, NUN, Institut National de la Recherche Agronomique, Nantes, France
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23
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Rubio K, Dobersch S, Barreto G. Functional interactions between scaffold proteins, noncoding RNAs, and genome loci induce liquid-liquid phase separation as organizing principle for 3-dimensional nuclear architecture: implications in cancer. FASEB J 2019; 33:5814-5822. [PMID: 30742773 DOI: 10.1096/fj.201802715r] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The eukaryotic cell nucleus consists of functionally specialized subcompartments. These nuclear subcompartments are biomolecular aggregates built of proteins, transcripts, and specific genome loci. The structure and function of each nuclear subcompartment are defined by the composition and dynamic interaction between these 3 components. The spatio-temporal localization of biochemical reactions into membraneless nuclear subcompartments can be achieved through liquid-liquid phase separation. Based on this organizing principle, nuclear subcompartments are droplet-like structures that adopt spherical shapes, flow, and fuse like liquids or gels. In the present review, we bring into the spotlight seminal works elucidating the functional interactions between scaffold proteins, noncoding RNAs, and genomic loci, thereby inducing liquid-liquid phase separation as an organizing principle for 3-dimensional nuclear architecture. We also discuss the implications in different cancer types as well as the potential use of this knowledge to develop novel therapeutic strategies against cancer.-Rubio, K., Dobersch, S., Barreto, G. Functional interactions between scaffold proteins, noncoding RNAs, and genome loci induce liquid-liquid phase separation as organizing principle for 3-dimensional nuclear architecture: implications in cancer.
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Affiliation(s)
- Karla Rubio
- Lung Cancer Epigenetic, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Stephanie Dobersch
- Lung Cancer Epigenetic, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Guillermo Barreto
- Lung Cancer Epigenetic, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany.,Laboratoire Croissance, Réparation, et Régénération Tissulaires (CRRET), Centre National de la Recherche Scientifique (CNRS) Équipe de Recherche Labellisée (ERL) 9215, Université Paris Est Créteil, Créteil, France.,Institute of Fundamental Medicine and Biology, Kazan (Volga Region) Federal University, Kazan, Russian Federation.,Excellence Cluster Cardio Pulmonary System (ECCPS), Universities of Giessen-Marburg Lung Center (UGMLC), Giessen, Germany.,German Center of Lung Research, Giessen, Germany
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24
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Beuzelin D, Kaeffer B. Exosomes and miRNA-Loaded Biomimetic Nanovehicles, a Focus on Their Potentials Preventing Type-2 Diabetes Linked to Metabolic Syndrome. Front Immunol 2018; 9:2711. [PMID: 30519245 PMCID: PMC6258775 DOI: 10.3389/fimmu.2018.02711] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 11/02/2018] [Indexed: 12/16/2022] Open
Abstract
Exosomes are small membrane vesicles of 30–150 nm, members of the extracellular vesicle family and secreted by various cell types. Different studies describe specific microRNA (miRNA) with altered expression in serum and/or plasma of patients suffering from diabetes or metabolic syndrome. Diabetic cardiomyocyte-derived exosomes loaded with miRNAs like miR-320-3p (or 320a) have been shown regulating angiogenesis on endothelial cell cultures. Insufficient myocardial angiogenesis is the major manifestation of diabetes-caused ischemic cardiovascular disease. Studies on transfer of functional microRNAs between mouse dendritic cells via exosomes have shown that some miRNAs (miR-320-3p, 29b-3p, 7a-5p) are distributed in immature and mature exosomes. Among these miRNAs, miR-320-3p is better known in epigenetics for silencing polr3d gene by binding to its promoter in Human Embryonic Kidney-293 cells. Moreover, quantitative and stoichiometric analysis of the microRNA content of exosomes highlights the lack of reliable natural source of such particles loaded with miRNA opening the need for tailoring exosomes or nanoparticles delivering efficiently miRNA intimately linked to immunity, metabolism and epigenetics in target cells. However, loading of extracellular mature miRNA into recipient cells comes with a cost by at least impeding dynamic localization of miRNAs in nucleoli or inefficient miRNA delivery due to rapid recycling by exonucleases. All these works are calling for the design of new biomimetic vehicles and in vivo assessment of miRNA functionality when delivered by natural or biomimetic nanoparticles in order to control metabolic diseases from infancy to adulthood.
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25
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Liu H, Lei C, He Q, Pan Z, Xiao D, Tao Y. Nuclear functions of mammalian MicroRNAs in gene regulation, immunity and cancer. Mol Cancer 2018; 17:64. [PMID: 29471827 PMCID: PMC5822656 DOI: 10.1186/s12943-018-0765-5] [Citation(s) in RCA: 225] [Impact Index Per Article: 37.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 01/12/2018] [Indexed: 12/19/2022] Open
Abstract
MicroRNAs (miRNAs) are endogenous non-coding RNAs that contain approximately 22 nucleotides. They serve as key regulators in various biological processes and their dysregulation is implicated in many diseases including cancer and autoimmune disorders. It has been well established that the maturation of miRNAs occurs in the cytoplasm and miRNAs exert post-transcriptional gene silencing (PTGS) via RNA-induced silencing complex (RISC) pathway in the cytoplasm. However, numerous studies reaffirm the existence of mature miRNA in the nucleus, and nucleus-cytoplasm transport mechanism has also been illustrated. Moreover, active regulatory functions of nuclear miRNAs were found including PTGS, transcriptional gene silencing (TGS), and transcriptional gene activation (TGA), in which miRNAs bind nascent RNA transcripts, gene promoter regions or enhancer regions and exert further effects via epigenetic pathways. Based on existing interaction rules, some miRNA binding sites prediction software tools are developed, which are evaluated in this article. In addition, we attempt to explore and review the nuclear functions of miRNA in immunity, tumorigenesis and invasiveness of tumor. As a non-canonical aspect of miRNA action, nuclear miRNAs supplement miRNA regulatory networks and could be applied in miRNA based therapies.
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Affiliation(s)
- Hongyu Liu
- Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, Hunan, 410008, China
- Key Laboratory of Carcinogenesis, Ministry of Education, Cancer Research Institute, School of Basic Medicine, Central South University, 110 Xiangya Road, Changsha, Hunan, 410078, China
| | - Cheng Lei
- Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, Hunan, 410008, China
- Key Laboratory of Carcinogenesis, Ministry of Education, Cancer Research Institute, School of Basic Medicine, Central South University, 110 Xiangya Road, Changsha, Hunan, 410078, China
| | - Qin He
- Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, Hunan, 410008, China
- Key Laboratory of Carcinogenesis, Ministry of Education, Cancer Research Institute, School of Basic Medicine, Central South University, 110 Xiangya Road, Changsha, Hunan, 410078, China
| | - Zou Pan
- Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, Hunan, 410008, China
- Key Laboratory of Carcinogenesis, Ministry of Education, Cancer Research Institute, School of Basic Medicine, Central South University, 110 Xiangya Road, Changsha, Hunan, 410078, China
| | - Desheng Xiao
- Department of Pathology, Xiangya Hospital, Central South University, Changsha, Hunan, 410078, China
| | - Yongguang Tao
- Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, Hunan, 410008, China.
- Key Laboratory of Carcinogenesis, Ministry of Education, Cancer Research Institute, School of Basic Medicine, Central South University, 110 Xiangya Road, Changsha, Hunan, 410078, China.
- Department of Thoracic Surgery, Second Xiangya Hospital, Central South University, Changsha, China.
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26
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Johannessen C, Moi L, Kiselev Y, Pedersen MI, Dalen SM, Braaten T, Busund LT. Expression and function of the miR-143/145 cluster in vitro and in vivo in human breast cancer. PLoS One 2017; 12:e0186658. [PMID: 29073169 PMCID: PMC5657998 DOI: 10.1371/journal.pone.0186658] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 10/01/2017] [Indexed: 12/21/2022] Open
Abstract
MicroRNAs (miRNAs) are small non-coding RNAs that function as post-transcriptional regulators of gene expression and are dysregulated in cancer. Studies of miRNAs to explore their potential as diagnostic and prognostic markers are of great scientific interest. Here, we investigate the functional properties and expression of the miR-143/145 cluster in breast cancer (BC) in vitro and in vivo. The ER positive MCF7, the HER2 positive SK-BR-3, and the triple negative cell line MDA-MB-231 were used to assess cell proliferation and cell invasion. Expression of miRNA in 108 breast cancers in the Norwegian Women and Cancer Study and 44 benign tissue controls were analyzed by microarray and validated by RT-PCR. Further, in situ hybridization (ISH) was used to study the cellular and subcellular distribution of the miRNAs. In vitro, miR-143 promoted proliferation of MCF7 and MDA-MB-231 cells, whereas miR-145 and the cotransfection of both miRNAs inhibited proliferation in all three cell lines. The cells’ invasive capacity was reduced after transfection and cotransfection of the miRNAs. In line with the tumor suppressive functions in vitro, the expression of miR-143 and miR-145 was lower in malignant compared to benign breast tissue, and lower in the more aggressive tumors with higher tumor grade, loss of ER and the basal-like phenotype. ISH revealed miR-143 to be cytoplasmatic and predominantly expressed in luminal cells in benign tissue, whilst miR-145 was nuclear and with strong staining in myoepithelial cells. Both miRNAs were present in malignant epithelial cells and stromal fibroblasts in BC. This study demonstrates that miR-143 and -145 have functional properties and expression patterns typical for tumor suppressors, but the function is influenced by cellular factors such as cell type and miRNA cotransfection. Further, the nuclear functions of miR-145 should be explored for a more complete understanding of the complexity of miRNA regulation and function in BC.
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Affiliation(s)
- Charles Johannessen
- Department of Medical Biology, UiT—The Arctic University of Norway, Tromsø, Norway
- * E-mail:
| | - Line Moi
- Department of Medical Biology, UiT—The Arctic University of Norway, Tromsø, Norway
- Department of Clinical Pathology, University Hospital of North Norway, Tromsø, Norway
| | - Yury Kiselev
- Department of Life Sciences and Health, Oslo and Akershus University College of Applied Sciences, Oslo, Norway
| | - Mona Irene Pedersen
- Department of Clinical Medicine, UiT—The Arctic University of Norway, Tromsø, Norway
| | - Stig Manfred Dalen
- Department of Clinical Pathology, University Hospital of North Norway, Tromsø, Norway
| | - Tonje Braaten
- Department of Community Medicine, UiT—The Arctic University of Norway, Tromsø, Norway
| | - Lill-Tove Busund
- Department of Medical Biology, UiT—The Arctic University of Norway, Tromsø, Norway
- Department of Clinical Pathology, University Hospital of North Norway, Tromsø, Norway
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27
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Catalanotto C, Cogoni C, Zardo G. MicroRNA in Control of Gene Expression: An Overview of Nuclear Functions. Int J Mol Sci 2016; 17:ijms17101712. [PMID: 27754357 PMCID: PMC5085744 DOI: 10.3390/ijms17101712] [Citation(s) in RCA: 743] [Impact Index Per Article: 92.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 10/04/2016] [Accepted: 10/07/2016] [Indexed: 12/14/2022] Open
Abstract
The finding that small non-coding RNAs (ncRNAs) are able to control gene expression in a sequence specific manner has had a massive impact on biology. Recent improvements in high throughput sequencing and computational prediction methods have allowed the discovery and classification of several types of ncRNAs. Based on their precursor structures, biogenesis pathways and modes of action, ncRNAs are classified as small interfering RNAs (siRNAs), microRNAs (miRNAs), PIWI-interacting RNAs (piRNAs), endogenous small interfering RNAs (endo-siRNAs or esiRNAs), promoter associate RNAs (pRNAs), small nucleolar RNAs (snoRNAs) and sno-derived RNAs. Among these, miRNAs appear as important cytoplasmic regulators of gene expression. miRNAs act as post-transcriptional regulators of their messenger RNA (mRNA) targets via mRNA degradation and/or translational repression. However, it is becoming evident that miRNAs also have specific nuclear functions. Among these, the most studied and debated activity is the miRNA-guided transcriptional control of gene expression. Although available data detail quite precisely the effectors of this activity, the mechanisms by which miRNAs identify their gene targets to control transcription are still a matter of debate. Here, we focus on nuclear functions of miRNAs and on alternative mechanisms of target recognition, at the promoter lavel, by miRNAs in carrying out transcriptional gene silencing.
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Affiliation(s)
- Caterina Catalanotto
- Department of Cellular Biotechnologies and Hematology, University of Rome Sapienza, Rome 00179, Italy.
| | - Carlo Cogoni
- Department of Cellular Biotechnologies and Hematology, University of Rome Sapienza, Rome 00179, Italy.
| | - Giuseppe Zardo
- Department of Cellular Biotechnologies and Hematology, University of Rome Sapienza, Rome 00179, Italy.
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Merhautova J, Demlova R, Slaby O. MicroRNA-Based Therapy in Animal Models of Selected Gastrointestinal Cancers. Front Pharmacol 2016; 7:329. [PMID: 27729862 PMCID: PMC5037200 DOI: 10.3389/fphar.2016.00329] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Accepted: 09/06/2016] [Indexed: 12/14/2022] Open
Abstract
Gastrointestinal cancer accounts for the 20 most frequent cancer diseases worldwide and there is a constant urge to bring new therapeutics with new mechanism of action into the clinical practice. Quantity of in vitro and in vivo evidences indicate, that exogenous change in pathologically imbalanced microRNAs (miRNAs) is capable of transforming the cancer cell phenotype. This review analyzed preclinical miRNA-based therapy attempts in animal models of gastric, pancreatic, gallbladder, and colorectal cancer. From more than 400 original articles, 26 was found to assess the effect of miRNA mimics, precursors, expression vectors, or inhibitors administered locally or systemically being an approach with relatively high translational potential. We have focused on mapping available information on animal model used (animal strain, cell line, xenograft method), pharmacological aspects (oligonucleotide chemistry, delivery system, posology, route of administration) and toxicology assessments. We also summarize findings in the field pharmacokinetics and toxicity of miRNA-based therapy.
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Affiliation(s)
- Jana Merhautova
- Molecular Oncology II - Solid Cancer, Central European Institute of Technology, Masaryk UniversityBrno, Czech Republic; Department of Pharmacology, Faculty of Medicine, Masaryk UniversityBrno, Czech Republic
| | - Regina Demlova
- Department of Pharmacology, Faculty of Medicine, Masaryk University Brno, Czech Republic
| | - Ondrej Slaby
- Molecular Oncology II - Solid Cancer, Central European Institute of Technology, Masaryk UniversityBrno, Czech Republic; Masaryk Memorial Cancer InstituteBrno, Czech Republic
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29
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Deep Sequencing Analysis of Nucleolar Small RNAs: Bioinformatics. Methods Mol Biol 2016. [PMID: 27576724 DOI: 10.1007/978-1-4939-3792-9_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2023]
Abstract
Small RNAs (size 20-30 nt) of various types have been actively investigated in recent years, and their subcellular compartmentalization and relative concentrations are likely to be of importance to their cellular and physiological functions. Comprehensive data on this subset of the transcriptome can only be obtained by application of high-throughput sequencing, which yields data that are inherently complex and multidimensional, as sequence composition, length, and abundance will all inform to the small RNA function. Subsequent data analysis, hypothesis testing, and presentation/visualization of the results are correspondingly challenging. We have constructed small RNA libraries derived from different cellular compartments, including the nucleolus, and asked whether small RNAs exist in the nucleolus and whether they are distinct from cytoplasmic and nuclear small RNAs, the miRNAs. Here, we present a workflow for analysis of small RNA sequencing data generated by the Ion Torrent PGM sequencer from samples derived from different cellular compartments.
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Abstract
Micro ribonucleic acid (microRNA) regulation and expression has become an emerging field in determining the mechanisms regulating a variety of inflammation-mediated diseases. Several studies have focused on specific microRNAs that are differentially expressed in cases of osteoarthritis. Furthermore, several targets of these miRNAs important in disease progression have also been identified. In this review, we focus on microRNA biogenesis, regulation, detection, and quantification with an emphasis on cellular localization and how these concepts may be linked to disease processes such as osteoarthritis. Next, we review the relationships of specific microRNAs to certain features and risk factors associated with osteoarthritis such as inflammation, obesity, autophagy, and cartilage homeostasis. We also identify certain microRNAs that are differentially expressed in osteoarthritis but have unidentified targets and functions in the disease state. Lastly, we identify the potential use of microRNAs for therapeutic purposes and also mention certain remedies that regulate microRNA expression.
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Affiliation(s)
- Gregory R Sondag
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University (NEOMED), 4209 State Route 44, Rootstown, OH, 44272, USA
| | - Tariq M Haqqi
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University (NEOMED), 4209 State Route 44, Rootstown, OH, 44272, USA.
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31
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Intracellular and extracellular microRNA: An update on localization and biological role. ACTA ACUST UNITED AC 2016; 51:33-49. [PMID: 27396686 DOI: 10.1016/j.proghi.2016.06.001] [Citation(s) in RCA: 148] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 06/24/2016] [Accepted: 06/24/2016] [Indexed: 12/12/2022]
Abstract
MicroRNA (miRNA) is a class of small non-coding RNAs which mediate post-transcriptional gene silencing (PTGS) by sequence-specific inhibition of target mRNAs translation and/or lowering their half-lives in the cytoplasm. Together with their binding partners, Argonaute (AGO) proteins, miRNAs form cores of RNA-induced silencing complexes (RISC). Despite a substantial progress in understanding RISC structure, until recently little was known about its localization in the cell. This review is aimed to provide an overview of the emerging picture of miRNA and RISC localization and function both in the intracellular space and outside of the cell. In contrast to the common assumption that PTGS occurs in the cytoplasm, it was found to operate mainly on the membranes of the endoplasmic reticulum (ER). Besides ER membranes miRNAs were found in all main cellular compartments including nucleus, nucleolus and mitochondria where they regulate various processes including transcription, translation, alternative splicing and DNA repair. Moreover, a certain pool of miRNAs may not be associated with RISC and carry completely different functions. Finally, the discovery of cell-free miRNAs in all biological fluids suggests that miRNAs might also act as signaling molecules outside the cell, and may be utilized as biomarkers for a variety of diseases. In this review we discuss miRNA secretion mechanisms and possible pathways of cell-cell communication via miRNA-containing exosomes in vivo.
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32
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Leung AKL. The Whereabouts of microRNA Actions: Cytoplasm and Beyond. Trends Cell Biol 2016; 25:601-610. [PMID: 26410406 DOI: 10.1016/j.tcb.2015.07.005] [Citation(s) in RCA: 131] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Revised: 06/23/2015] [Accepted: 07/17/2015] [Indexed: 12/31/2022]
Abstract
MicroRNAs (miRNAs) are a conserved class of approximately 22 nucleotide (nt) short noncoding RNAs that normally silence gene expression via translational repression and/or degradation of targeted mRNAs in plants and animals. Identifying the whereabouts of miRNAs potentially informs miRNA functions, some of which are perhaps specialized to specific cellular compartments. In this review, the significance of miRNA localizations in the cytoplasm, including those at RNA granules and endomembranes, and the export of miRNAs to extracellular space will be discussed. How miRNA localizations and functions are regulated by protein modifications on the core miRNA-binding protein Argonaute (AGO) during normal and stress conditions will be explored, and in conclusion new AGO partners, non-AGO miRNA-binding proteins, and the emergent understanding of miRNAs found in the nucleoplasm, nucleoli, and mitochondria will be discussed.
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Affiliation(s)
- Anthony K L Leung
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA.
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Atwood BL, Woolnough JL, Lefevre GM, Saint Just Ribeiro M, Felsenfeld G, Giles KE. Human Argonaute 2 Is Tethered to Ribosomal RNA through MicroRNA Interactions. J Biol Chem 2016; 291:17919-28. [PMID: 27288410 DOI: 10.1074/jbc.m116.725051] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Indexed: 11/06/2022] Open
Abstract
The primary role of the RNAi machinery is to promote mRNA degradation within the cytoplasm in a microRNA-dependent manner. However, both Dicer and the Argonaute protein family have expanded roles in gene regulation within the nucleus. To further our understanding of this role, we have identified chromatin binding sites for AGO2 throughout the 45S region of the human rRNA gene. The location of these sites was mirrored by the positions of AGO2 cross-linking sites identified via PAR-CLIP-seq. AGO2 binding to the rRNA within the nucleus was confirmed by RNA immunoprecipitation and quantitative-PCR. To explore a possible mechanism by which AGO2 could be recruited to the rRNA, we identified 1174 regions within the 45S rRNA transcript that have the ability to form a perfect duplex with position 2-6 (seed sequence) of each microRNA expressed in HEK293T cells. Of these potential AGO2 binding sites, 479 occurred within experimentally verified AGO2-rRNA cross-linking sites. The ability of AGO2 to cross-link to rRNA was almost completely lost in a DICER knock-out cell line. The transfection of miR-92a-2-3p into the noDICE cell line facilitated AGO2 cross-linking at a region of the rRNA that has a perfect seed match at positions 3-8, including a single G-U base pair. Knockdown of AGO2 within HEK293T cells causes a slight, but statistically significant increase in the overall rRNA synthesis rate but did not impact the ratio of processing intermediates or the recruitment of the Pol I transcription factor UBTF.
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Affiliation(s)
- Blake L Atwood
- From the UAB Stem Cell Institute, Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama 35209 and
| | - Jessica L Woolnough
- From the UAB Stem Cell Institute, Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama 35209 and
| | - Gaelle M Lefevre
- Laboratory of Molecular Biology, NIDDK, National Institutes of Health, Bethesda, Maryland
| | - Mariana Saint Just Ribeiro
- From the UAB Stem Cell Institute, Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama 35209 and
| | - Gary Felsenfeld
- Laboratory of Molecular Biology, NIDDK, National Institutes of Health, Bethesda, Maryland
| | - Keith E Giles
- From the UAB Stem Cell Institute, Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama 35209 and
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Donzelli S, Cioce M, Muti P, Strano S, Yarden Y, Blandino G. MicroRNAs: Non-coding fine tuners of receptor tyrosine kinase signalling in cancer. Semin Cell Dev Biol 2016; 50:133-42. [PMID: 26773212 DOI: 10.1016/j.semcdb.2015.12.020] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 12/23/2015] [Indexed: 12/19/2022]
Abstract
Emerging evidence point to a crucial role for non-coding RNAs in modulating homeostatic signaling under physiological and pathological conditions. MicroRNAs, the best-characterized non-coding RNAs to date, can exquisitely integrate spatial and temporal signals in complex networks, thereby confer specificity and sensitivity to tissue response to changes in the microenvironment. MicroRNAs appear as preferential partners for Receptor Tyrosine Kinases (RTKs) in mediating signaling under stress conditions. Stress signaling can be especially relevant to disease. Here we focus on the ability of microRNAs to mediate RTK signaling in cancer, by acting as both tumor suppressors and oncogenes. We will provide a few general examples of microRNAs modulating specific tumorigenic functions downstream of RTK signaling and integrate oncogenic signals from multiple RTKs. A special focus will be devoted to epidermal growth factor receptor (EGFR) signaling, a system offering relatively rich information. We will explore the role of selected microRNAs as bidirectional modulators of EGFR functions in cancer cells. In addition, we will present the emerging evidence for microRNAs being specifically modulated by oncogenic EGFR mutants and we will discuss how this impinges on EGFRmut driven chemoresistance, which fits into the tumor heterogeneity-driven cancer progression. Finally, we discuss how other non-coding RNA species are emerging as important modulators of cancer progression and why the scenario depicted herein is destined to become increasingly complex in the future.
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Affiliation(s)
- Sara Donzelli
- Translational Oncogenomics, Regina Elena National Cancer Institute, 00144 Rome, Italy
| | - Mario Cioce
- Translational Oncogenomics, Regina Elena National Cancer Institute, 00144 Rome, Italy
| | - Paola Muti
- Dept of Oncology, McMaster University, Hamilton, On L8V1C3, Canada
| | - Sabrina Strano
- Molecular Chemoprevention Units, Regina Elena National Cancer Institute, 00144 Rome, Italy; Dept of Oncology, McMaster University, Hamilton, On L8V1C3, Canada
| | - Yosef Yarden
- Dept of Biological Regulation, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Giovanni Blandino
- Translational Oncogenomics, Regina Elena National Cancer Institute, 00144 Rome, Italy; Dept of Oncology, McMaster University, Hamilton, On L8V1C3, Canada.
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Abstract
The nucleolus is the largest nuclear organelle and is the primary site of ribosome subunit biogenesis in eukaryotic cells. It is assembled around arrays of ribosomal DNA genes, forming specific chromosomal features known as nucleolar organizing regions (NORs) which are the sites of ribosomal DNA transcription. While the nucleolus main activity involve different steps of ribosome biogenesis, the presence of proteins with no obvious relationship with ribosome subunit production suggests additional functions for the nucleolus, such as regulation of mitosis, cell cycle progression, stress response and biogenesis of multiple ribonucleoprotein complexes. The many novel factors and separate classes of proteins identified within the nucleolus support this view that the nucleolus may perform additional functions beyond its known role in ribosome subunit biogenesis. Here we review our knowledge of the nucleolar functions and will provide a detailed picture of how the nucleolus is involved in many cellular pathways.
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Affiliation(s)
- David P. Bazett-Jones
- Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Ontario Canada
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36
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Abstract
We previously discovered that a set of 5 microRNAs are concentrated in the nucleolus of rat myoblasts. We now report that several mRNAs are also localized in the nucleoli of these cells as determined by microarray analysis of RNA from purified nucleoli. Among the most abundant of these nucleolus-localized mRNAs is that encoding insulin-like growth factor 2 (IGF2), a regulator of myoblast proliferation and differentiation. The presence of IGF2 mRNA in nucleoli was confirmed by fluorescence in situ hybridization, and RT-PCR experiments demonstrated that these nucleolar transcripts are spliced, thus arriving from the nucleoplasm. Bioinformatics analysis predicted canonically structured, highly thermodynamically stable interactions between IGF2 mRNA and all 5 of the nucleolus-localized microRNAs. These results raise the possibility that the nucleolus is a staging site for setting up particular mRNA-microRNA interactions prior to export to the cytoplasm.
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Affiliation(s)
- Pablo Reyes-Gutierrez
- a Program in Cell and Developmental Dynamics; Department of Biochemistry and Molecular Pharmacology; University of Massachusetts Medical School ; Worcester , MA USA
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37
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Doubly Spliced RNA of Hepatitis B Virus Suppresses Viral Transcription via TATA-Binding Protein and Induces Stress Granule Assembly. J Virol 2015; 89:11406-19. [PMID: 26339052 DOI: 10.1128/jvi.00949-15] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Accepted: 08/26/2015] [Indexed: 12/13/2022] Open
Abstract
UNLABELLED The risk of liver cancer in patients infected with the hepatitis B virus (HBV) and their clinical response to interferon alpha therapy vary based on the HBV genotype. The mechanisms underlying these differences in HBV pathogenesis remain unclear. In HepG2 cells transfected with a mutant HBV(G2335A) expression plasmid that does not transcribe the 2.2-kb doubly spliced RNA (2.2DS-RNA) expressed by wild-type HBV genotype A, the level of HBV pregenomic RNA (pgRNA) was higher than that in cells transfected with an HBV genotype A expression plasmid. By using cotransfection with HBV genotype D and 2.2DS-RNA expression plasmids, we found that a reduction of pgRNA was observed in the cells even in the presence of small amounts of the 2.2DS-RNA plasmid. Moreover, ectopic expression of 2.2DS-RNA in the HBV-producing cell line 1.3ES2 reduced the expression of pgRNA. Further analysis showed that exogenously transcribed 2.2DS-RNA inhibited a reconstituted transcription in vitro. In Huh7 cells ectopically expressing 2.2DS-RNA, RNA immunoprecipitation revealed that 2.2DS-RNA interacted with the TATA-binding protein (TBP) and that nucleotides 432 to 832 of 2.2DS-RNA were required for efficient TBP binding. Immunofluorescence experiments showed that 2.2DS-RNA colocalized with cytoplasmic TBP and the stress granule components, G3BP and poly(A)-binding protein 1 (PABP1), in Huh7 cells. In conclusion, our study reveals that 2.2DS-RNA acts as a repressor of HBV transcription through an interaction with TBP that induces stress granule formation. The expression of 2.2DS-RNA may be one of the viral factors involved in viral replication, which may underlie differences in clinical outcomes of liver disease and responses to interferon alpha therapy between patients infected with different HBV genotypes. IMPORTANCE Patients infected with certain genotypes of HBV have a lower risk of hepatocellular carcinoma and exhibit a more favorable response to antiviral therapy than patients infected with other HBV genotypes. Using cultured human hepatoma cells as a model of HBV infection, we found that the expression of 2.2DS-RNA caused a decrease in HBV replication. In cultured cells, the ectopic expression of 2.2DS-RNA obviously reduced the intracellular levels of HBV mRNAs. Our analysis of the 2.2DS-RNA-mediated suppression of viral RNA expression showed that 2.2DS-RNA inhibited transcription via binding to the TATA-binding protein and stress granule proteins. Our findings suggest that the 2.2DS-RNA acts as a suppressive noncoding RNA that modulates HBV replication, which may in turn influence the development of chronic hepatitis B.
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Romero-Cordoba SL, Salido-Guadarrama I, Rodriguez-Dorantes M, Hidalgo-Miranda A. miRNA biogenesis: biological impact in the development of cancer. Cancer Biol Ther 2015; 15:1444-55. [PMID: 25482951 PMCID: PMC4622859 DOI: 10.4161/15384047.2014.955442] [Citation(s) in RCA: 178] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
microRNAs (miRNAs) are non coding RNAs with different biological functions and pathological implications. Given their role as post-transcriptional gene expression regulators, they are involved in several important physiological processes like development, cell differentiation and cell signaling. miRNAs act as modulators of gene expression programs in different diseases, particularly in cancer, where they act through the repression of genes which are critical for carcinogenesis. The expression level of mature miRNAs is the result of a fine mechanism of biogenesis, carried out by different enzymatic complexes that exert their function at transcriptional and post-transcriptional levels. In this review, we will focus our discussion on the alterations in the miRNA biogenesis machinery, and its impact on the establishment and development of cancer programs.
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Key Words
- Ago2, Argonaute 2 protein
- Ars2, Arsenic Resistance protein 2
- DGCR8, DiGeorge syndrome Critical Region 8 protein
- EMT, epithelial–mesenchymal transition
- KSRP, KH-type splicing regulatory protein
- MK2, MAPK-activated protein kinase 2
- PABP, poly(A)-binding protein
- PACT, kinase R–activating protein
- PRC2, Polycomb repressor complex
- RISC, RNA-induced silencing complex
- TRBP, TAR RNA binding protein
- TUT4, terminal uridine transferase-4
- XPO5, exportin 5
- cancer
- cellular signaling
- circRNA, circular RNA
- hnRNPs, heterogeneous nuclear ribonucleoproteins
- miRNA biogenesis
- miRNAs, microRNAs
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Lam YW, Trinkle-Mulcahy L. New insights into nucleolar structure and function. F1000PRIME REPORTS 2015; 7:48. [PMID: 26097721 PMCID: PMC4447046 DOI: 10.12703/p7-48] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The nucleolus is a non-membrane-bound nuclear organelle found in all eukaryotes. It is the quintessential ‘RNA-seeded’ nuclear body, forming around specific chromosomal features called nucleolar organizing regions that contain arrays of ribosomal DNA. Assembly is triggered by activation of RNA polymerase I-mediated transcription and regulated in mammalian cells in a cell cycle-dependent manner. Although the nucleolus is best known for its role in coordinating ribosome biogenesis, biochemical and proteomic analyses have revealed a much wider functional complexity than previously appreciated, including roles in cell cycle regulation, DNA damage sensing and repair, pre-mRNA processing, telomere metabolism, processing of non-coding RNAs, and coordination of the cellular response to various stresses. Despite these advances, much remains to be learned about the full range of biological processes that occur within, or involve, this organelle and how its assembly/disassembly and functional reorganization in response to various stimuli are regulated. Here, we review the impact of recent studies that provide major insights into these fundamental questions, and we highlight the therapeutic potential of targeting nucleolar pathways.
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Affiliation(s)
- Yun Wah Lam
- Department of Biology and Chemistry, City University of Hong KongTat Chee Avenue, KowloonHong Kong
| | - Laura Trinkle-Mulcahy
- Department of Cellular & Molecular Medicine and Ottawa Institute of Systems Biology, University of Ottawa451 Smyth Road, Ottawa, ON, K1H 8M5Canada
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40
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miRNA in situ hybridization in circulating tumor cells--MishCTC. Sci Rep 2015; 5:9207. [PMID: 25777797 PMCID: PMC4361864 DOI: 10.1038/srep09207] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Accepted: 02/09/2015] [Indexed: 12/12/2022] Open
Abstract
Circulating tumor cells (CTCs) must be phenotypically and genetically characterized before they can be utilized in clinical applications. Here, we present the first protocol for the detection of miRNAs in CTCs using in situ hybridization (ISH) combined with immunomagnetic selection based on cytokeratin (CK) expression and immunocytochemistry. Locked-Nucleic Acid (LNA) probes associated with an enzyme-labeled fluorescence (ELF) signal amplification approach were used to detect miRNA-21 in CTCs. This protocol was optimized using both epithelial tumor (MDA-MB468) and epithelial non-tumor (MCF-10A) cell lines, and miRNA-21 was selected as the target miRNA because of its known role as an onco-miRNA. Hematopoietic cells do not express miRNA-21; thus, miRNA-21 is an ideal marker for detecting CTCs. Peripheral blood samples were taken from 25 cancer patients and these samples were analyzed using our developed protocol. Of the 25 samples, 11 contained CTCs. For all 11 CTC-positive samples, the isolated CTCs expressed both CK and miRNA-21. Finally, the protocol was applied to monitor miRNA-21 expression in epithelial to mesenchymal transition (EMT)-induced MCF-7 cells, an epithelial tumor cell line. CK expression was lost in these cells, whereas miRNA-21 was still expressed, suggesting that miRNA-21 might be a good marker for detecting CTCs with an EMT phenotype.
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41
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Borralho PM, Rodrigues CMP, Steer CJ. microRNAs in Mitochondria: An Unexplored Niche. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2015; 887:31-51. [PMID: 26662985 DOI: 10.1007/978-3-319-22380-3_3] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Mitochondria are pivotal organelles involved in the regulation of a myriad of crucial biological processes, including cell survival and cell death, rendering mitochondrial dysfunction a relevant step in numerous pathophysiological processes. MicroRNAs (miRNAs) are endogenous small noncoding RNAs that add a new layer of complexity to the control of gene expression. miRNAs function as master regulators and fine-tuners of gene expression, primarily via posttranscriptional mechanisms, and are increasingly demonstrated as a paramount class of endogenous molecules with relevant diagnostic, prognostic, and therapeutic applications. miRNAs and other RNA interference have recently been reported to be present in mitochondria from several species, and we are now beginning to unveil mitochondrial miRNA transport mechanisms, biological function and targets to ascertain their role in this unexplored niche. Here, we describe miRNA biogenesis and present key findings regarding miRNA localization to mitochondria, origin, putative biological function, and implications for human disease.
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Affiliation(s)
- Pedro M Borralho
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Lisbon, Portugal
| | - Cecília M P Rodrigues
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Lisbon, Portugal
| | - Clifford J Steer
- Departments of Medicine, and Genetics, Cell Biology and Development, University of Minnesota Medical School, VFW Cancer Research Center, 406 Harvard Street S.E., Minneapolis, MN, 55455, USA.
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42
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Borralho PM, Steer CJ, Rodrigues CMP. Isolation of mitochondria from liver and extraction of total RNA and protein: analyses of microRNA and protein expressions. Methods Mol Biol 2015; 1241:9-22. [PMID: 25308484 DOI: 10.1007/978-1-4939-1875-1_2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Several studies have indicated the presence of microRNAs (miRNAs) within mitochondria, although the origin, as well as the biological function of these mitochondrially located miRNAs is largely unknown. The identification and significance of this subcellular localization is gaining increasing relevance to the pathogenesis of certain disease states. Here we describe the isolation of highly purified mitochondria from rat liver by differential centrifugation, followed by RNAse A treatment to eliminate contaminating RNA. The coupled extraction of total RNA and protein is a more efficient design for allowing the downstream evaluation of miRNA and protein expression in mitochondria.
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Affiliation(s)
- Pedro M Borralho
- Faculty of Pharmacy, Research Institute for Medicines (iMed.ULisboa), Universidade de Lisboa, Lisbon, 1649-003, Portugal
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43
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Abstract
The nucleolus was one of the first subcellular organelles to be isolated from the cell. The advent of modern proteomic techniques has resulted in the identification of thousands of proteins in this organelle, and live cell imaging technology has allowed the study of the dynamics of these proteins. However, the limitations of current nucleolar isolation methods hinder the further exploration of this structure. In particular, these methods require the use of a large number of cells and tedious procedures. In this chapter we describe a new and improved nucleolar isolation method for cultured adherent cells. In this method cells are snap-frozen before direct sonication and centrifugation onto a sucrose cushion. The nucleoli can be obtained within a time as short as 20 min, and the high yield allows the use of less starting material. As a result, this method can capture rapid biochemical changes in nucleoli by freezing the cells at a precise time, hence faithfully reflecting the protein composition of nucleoli at the specified time point. This protocol will be useful for proteomic studies of dynamic events in the nucleolus and for better understanding of the biology of mammalian cells.
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Affiliation(s)
- Zhou Fang Li
- Department of Biology, South University of Science and Technology of China, 1088 Xueyuan Blvd., Nanshan, Shenzhen, Guangdong, P.R. China,
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Bai B, Yegnasubramanian S, Wheelan SJ, Laiho M. RNA-Seq of the nucleolus reveals abundant SNORD44-derived small RNAs. PLoS One 2014; 9:e107519. [PMID: 25203660 PMCID: PMC4159348 DOI: 10.1371/journal.pone.0107519] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Accepted: 08/18/2014] [Indexed: 01/21/2023] Open
Abstract
Small non-coding RNAs represent RNA species that are not translated to proteins, but which have diverse and broad functional activities in physiological and pathophysiological states. The knowledge of these small RNAs is rapidly expanding in part through the use of massive parallel (deep) sequencing efforts. We present here the first deep sequencing of small RNomes in subcellular compartments with particular emphasis on small RNAs (sRNA) associated with the nucleolus. The vast majority of the cellular, cytoplasmic and nuclear sRNAs were identified as miRNAs. In contrast, the nucleolar sRNAs had a unique size distribution consisting of 19-20 and 25 nt RNAs, which were predominantly composed of small snoRNA-derived box C/D RNAs (termed as sdRNA). Sequences from 47 sdRNAs were identified, which mapped to both 5' and 3' ends of the snoRNAs, and retained conserved box C or D motifs. SdRNA reads mapping to SNORD44 comprised 74% of all nucleolar sdRNAs, and were confirmed by Northern blotting as comprising both 20 and 25 nt RNAs. A novel 120 nt SNORD44 form was also identified. The expression of the SNORD44 sdRNA and 120 nt form was independent of Dicer/Drosha-mediated processing pathways but was dependent on the box C/D snoRNP proteins/sno-ribonucleoproteins fibrillarin and NOP58. The 120 nt SNORD44-derived RNA bound to fibrillarin suggesting that C/D sno-ribonucleoproteins are involved in regulating the stability or processing of SNORD44. This study reveals sRNA cell-compartment specific expression and the distinctive unique composition of the nucleolar sRNAs.
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Affiliation(s)
- Baoyan Bai
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Srinivasan Yegnasubramanian
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Sarah J. Wheelan
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Marikki Laiho
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
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Roberts TC. The MicroRNA Biology of the Mammalian Nucleus. MOLECULAR THERAPY. NUCLEIC ACIDS 2014; 3:e188. [PMID: 25137140 PMCID: PMC4221600 DOI: 10.1038/mtna.2014.40] [Citation(s) in RCA: 132] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Accepted: 07/08/2014] [Indexed: 12/13/2022]
Abstract
MicroRNAs (miRNAs) are a class of genome-encoded small RNAs that are primarily considered to be post-transcriptional negative regulators of gene expression acting in the cytoplasm. Over a decade of research has focused on this canonical paradigm of miRNA function, with many success stories. Indeed, miRNAs have been identified that act as master regulators of a myriad of cellular processes, and many miRNAs are promising therapeutic targets or disease biomarkers. However, it is becoming increasingly apparent that the canonical view of miRNA function is incomplete. Several lines of evidence now point to additional functions for miRNAs in the nucleus of the mammalian cell. The majority of cellular miRNAs are present in both the nucleus and the cytoplasm, and certain miRNAs show specific nuclear enrichment. Additionally, some miRNAs colocalize with sub-nuclear structures such as the nucleolus and chromatin. Multiple components of the miRNA processing machinery are present in the nuclear compartment and are shuttled back and forth across the nuclear envelope. In the nucleus, miRNAs act to regulate the stability of nuclear transcripts, induce epigenetic alterations that either silence or activate transcription at specific gene promoters, and modulate cotranscriptional alternative splicing events. Nuclear miRNA-directed gene regulation constitutes a departure from the prevailing view of miRNA function and as such, warrants detailed further investigation.
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Affiliation(s)
- Thomas C Roberts
- 1] Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California, USA [2] Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
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Melo SA, Esteller M. Disruption of microRNA nuclear transport in human cancer. Semin Cancer Biol 2014; 27:46-51. [DOI: 10.1016/j.semcancer.2014.02.012] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Accepted: 02/25/2014] [Indexed: 12/24/2022]
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Role of microRNA-29b in the ochratoxin A-induced enhanced collagen formation in human kidney cells. Toxicology 2014; 324:116-22. [PMID: 25091173 DOI: 10.1016/j.tox.2014.07.012] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Revised: 07/16/2014] [Accepted: 07/31/2014] [Indexed: 11/23/2022]
Abstract
Ochratoxin A (OTA) is an ubiquitous mycotoxin suspected to cause fibrotic kidney diseases. The involvement of mircoRNAs in these processes is unknown. Here, we investigated the role of the anti-fibrotic miR-29b in OTA-induced alterations of cellular collagen homeostasis. OTA exposure of human embryonic kidney cells (HEK293) cells led to an increase of collagen I, III and IV protein amounts without changes in collagen mRNA expression levels, indicating post-transcriptionally mediated mechanisms potentially involving microRNAs and 3'UTRs of collagen mRNAs. This was confirmed by enhanced luciferase activity of a collagen1A1-3'UTR reporter plasmid after OTA exposure. OTA also enhanced the luciferase activity of a reporter plasmid containing the seed region of miR-29b showing that OTA diminishes miR-29b action. Additionally, OTA induced an altered intracellular distribution of miR-29b leading to decreased cytoplasmic abundance of miR-29b. Abundantly added miR-29b (miR-29b clamp) completely prevented OTA-induced collagen formation. In summary, we show that OTA has the potential to initiate or support the development of fibrotic kidney diseases by involving post-transcriptional regulation mechanisms comprising miR-29b. OTA reduces the impact of miR-29b and thus enhances collagen protein expression. These findings allow a new perspective on how the exposure to nanomolar OTA concentrations can lead to fibrotic tissue alterations.
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48
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Mahboubi H, Stochaj U. Nucleoli and Stress Granules: Connecting Distant Relatives. Traffic 2014; 15:1179-93. [DOI: 10.1111/tra.12191] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 06/30/2014] [Accepted: 06/30/2014] [Indexed: 12/19/2022]
Affiliation(s)
- Hicham Mahboubi
- Department of Physiology; McGill University; 3655 Promenade Sir William Osler Montreal Quebec H3G 1Y6 Canada
| | - Ursula Stochaj
- Department of Physiology; McGill University; 3655 Promenade Sir William Osler Montreal Quebec H3G 1Y6 Canada
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Mitochondrial MicroRNAs and Their Potential Role in Cell Function. CURRENT PATHOBIOLOGY REPORTS 2014. [DOI: 10.1007/s40139-014-0047-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Small RNA expression and deep sequencing analyses of the nucleolus reveal the presence of nucleolus-associated microRNAs. FEBS Open Bio 2014; 4:441-9. [PMID: 24918059 PMCID: PMC4050192 DOI: 10.1016/j.fob.2014.04.010] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Revised: 04/04/2014] [Accepted: 04/24/2014] [Indexed: 12/04/2022] Open
Abstract
miRNA expression arrays and RNA Seq were employed for unbiased spatial analyses of miRNAs. Small RNomics of subcellular compartments revealed the presence of miRNAs in the nucleolus. Several miRNAs were detected at low abundance in cancer cell nucleoli. The nucleolar abundance of miR-31 was dependent on CRM1 export factor.
Micro RNAs (miRNA) are non-coding RNAs expressed in the cytoplasm as their mature, 21–22-nucleotide short forms. More recently, mature miRNAs have also been detected in the nucleus, raising the possibility that their spatial distribution may be more complex than anticipated. Here we undertook comprehensive systematic analyses of miRNA distribution in several subcellular compartments of human cancer cells. In particular, we focused on the potential presence of miRNAs in the nucleolus, which contains an abundance of small non-coding RNAs. We employed two miRNA expression array platforms and small RNA deep sequencing of small RNAs isolated from cells, nuclei, cytoplasm and the nucleoli. We developed an assay to compare RNAs of isolated nucleoli before and after denaturation and used Northern hybridization to verify the presence of miRNAs in the subcellular compartments. Consistently, we found more than 10 miRNAs associated with the nucleolar preparations. Several miRNAs had greater relative abundance in the nucleolus compared to the other compartments. The nucleolar presence of miRNAs was independent of Dicer and the main activity of the nucleolus, RNA polymerase I transcription, but was dependent on CRM1 previously associated with nucleolar trafficking of small nucleolar RNAs. These results highlight the complexity of miRNA spatial arrangement and regulation.
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