1
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Billi M, De Marinis E, Gentile M, Nervi C, Grignani F. Nuclear miRNAs: Gene Regulation Activities. Int J Mol Sci 2024; 25:6066. [PMID: 38892257 PMCID: PMC11172810 DOI: 10.3390/ijms25116066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2024] [Revised: 05/29/2024] [Accepted: 05/29/2024] [Indexed: 06/21/2024] Open
Abstract
MicroRNAs (miRNAs) are small non-coding RNAs which contribute to the regulation of many physiological and pathological processes. Conventionally, miRNAs perform their activity in the cytoplasm where they regulate gene expression by interacting in a sequence-specific manner with mature messenger RNAs. Recent studies point to the presence of mature miRNAs in the nucleus. This review summarizes current findings regarding the molecular activities of nuclear miRNAs. These molecules can regulate gene expression at the transcriptional level by directly binding DNA on the promoter or the enhancer of regulated genes. miRNAs recruit different protein complexes to these regions, resulting in activation or repression of transcription, through a number of molecular mechanisms. Hematopoiesis is presented as a paradigmatic biological process whereby nuclear miRNAs possess a relevant regulatory role. Nuclear miRNAs can influence gene expression by affecting nuclear mRNA processing and by regulating pri-miRNA maturation, thus impacting the biogenesis of miRNAs themselves. Overall, nuclear miRNAs are biologically active molecules that can be critical for the fine tuning of gene expression and deserve further studies in a number of physiological and pathological conditions.
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Affiliation(s)
- Monia Billi
- General Pathology and Department of Medicine, University of Perugia, 06132 Perugia, Italy;
| | - Elisabetta De Marinis
- Department of Medical-Surgical Sciences and Biotechnologies, University of Rome “La Sapienza”, 04100 Latina, Italy; (E.D.M.); (M.G.); (C.N.)
| | - Martina Gentile
- Department of Medical-Surgical Sciences and Biotechnologies, University of Rome “La Sapienza”, 04100 Latina, Italy; (E.D.M.); (M.G.); (C.N.)
| | - Clara Nervi
- Department of Medical-Surgical Sciences and Biotechnologies, University of Rome “La Sapienza”, 04100 Latina, Italy; (E.D.M.); (M.G.); (C.N.)
| | - Francesco Grignani
- General Pathology and Department of Medicine, University of Perugia, 06132 Perugia, Italy;
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2
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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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3
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Gu J, Li Y, Tian Y, Zhang Y, Cheng Y, Tang Y. Noncanonical functions of microRNAs in the nucleus. Acta Biochim Biophys Sin (Shanghai) 2024; 56:151-161. [PMID: 38167929 PMCID: PMC10984876 DOI: 10.3724/abbs.2023268] [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: 09/02/2023] [Accepted: 11/03/2023] [Indexed: 01/05/2024] Open
Abstract
MicroRNAs (miRNAs) are small noncoding RNAs (ncRNAs) that play their roles in the regulation of physiological and pathological processes. Originally, it was assumed that miRNAs only modulate gene expression posttranscriptionally in the cytoplasm by inducing target mRNA degradation. However, with further research, evidence shows that mature miRNAs also exist in the cell nucleus, where they can impact gene transcription and ncRNA maturation in several ways. This review provides an overview of novel models of nuclear miRNA functions. Some of the models remain to be verified by experimental evidence, and more details of the miRNA regulation network remain to be discovered in the future.
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Affiliation(s)
- Jiayi Gu
- College of Basic Medical SciencesShanghai Jiao Tong University School of MedicineShanghai200001China
| | - Yuanan Li
- College of Basic Medical SciencesShanghai Jiao Tong University School of MedicineShanghai200001China
| | - Youtong Tian
- College of Basic Medical SciencesShanghai Jiao Tong University School of MedicineShanghai200001China
| | - Yehao Zhang
- College of Basic Medical SciencesShanghai Jiao Tong University School of MedicineShanghai200001China
| | - Yongjun Cheng
- Department of Rheumatologythe First People’s Hospital of WenlingWenling317500China
| | - Yuanjia Tang
- Shanghai Institute of Rheumatology/Department of RheumatologyRenji HospitalShanghai Jiao Tong University School of MedicineShanghai200001China
- State Key Laboratory of Oncogenes and Related GenesShanghai Cancer InstituteRenji HospitalShanghai200031China
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4
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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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5
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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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6
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Tsue AF, Kania EE, Lei DQ, Fields R, McGann CD, Hershberg E, Deng X, Kihiu M, Ong SE, Disteche CM, Kugel S, Beliveau BJ, Schweppe DK, Shechner DM. Oligonucleotide-directed proximity-interactome mapping (O-MAP): A unified method for discovering RNA-interacting proteins, transcripts and genomic loci in situ. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.19.524825. [PMID: 36711823 PMCID: PMC9882335 DOI: 10.1101/2023.01.19.524825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Throughout biology, RNA molecules form complex networks of molecular interactions that are central to their function, but remain challenging to investigate. Here, we introduce Oligonucleotide-mediated proximity-interactome MAPping (O-MAP), a straightforward method for elucidating the biomolecules near an RNA of interest, within its native cellular context. O-MAP uses programmable oligonucleotide probes to deliver proximity-biotinylating enzymes to a target RNA, enabling nearby molecules to be enriched by streptavidin pulldown. O-MAP induces exceptionally precise RNA-localized in situ biotinylation, and unlike alternative methods it enables straightforward optimization of its targeting accuracy. Using the 47S pre-ribosomal RNA and long noncoding RNA Xist as models, we develop O-MAP workflows for unbiased discovery of RNA-proximal proteins, transcripts, and genomic loci. This revealed unexpected co-compartmentalization of Xist and other chromatin-regulatory RNAs and enabled systematic characterization of nucleolar-chromatin interactions across multiple cell lines. O-MAP is portable to cultured cells, organoids, and tissues, and to RNAs of various lengths, abundances, and sequence composition. And, O-MAP requires no genetic manipulation and uses exclusively off-the-shelf parts. We therefore anticipate its application to a broad array of RNA phenomena.
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7
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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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8
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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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9
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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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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: 39] [Impact Index Per Article: 13.0] [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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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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12
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Lemus-Diaz N, Ferreira RR, Bohnsack KE, Gruber J, Bohnsack MT. The human box C/D snoRNA U3 is a miRNA source and miR-U3 regulates expression of sortin nexin 27. Nucleic Acids Res 2020; 48:8074-8089. [PMID: 32609813 PMCID: PMC7430653 DOI: 10.1093/nar/gkaa549] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 05/29/2020] [Accepted: 06/22/2020] [Indexed: 02/06/2023] Open
Abstract
MicroRNAs (miRNAs) are important regulators of eukaryotic gene expression and their dysfunction is often associated with cancer. Alongside the canonical miRNA biogenesis pathway involving stepwise processing and export of pri- and pre-miRNA transcripts by the microprocessor complex, Exportin 5 and Dicer, several alternative mechanisms of miRNA production have been described. Here, we reveal that the atypical box C/D snoRNA U3, which functions as a scaffold during early ribosome assembly, is a miRNA source. We show that a unique stem-loop structure in the 5' domain of U3 is processed to form short RNA fragments that associate with Argonaute. miR-U3 production is independent of Drosha, and an increased amount of U3 in the cytoplasm in the absence of Dicer suggests that a portion of the full length snoRNA is exported to the cytoplasm where it is efficiently processed into miRNAs. Using reporter assays, we demonstrate that miR-U3 can act as a low proficiency miRNA in vivo and our data support the 3' UTR of the sortin nexin SNX27 mRNA as an endogenous U3-derived miRNA target. We further reveal that perturbation of U3 snoRNP assembly induces miR-U3 production, highlighting potential cross-regulation of target mRNA expression and ribosome production.
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Affiliation(s)
- Nicolas Lemus-Diaz
- Department of Molecular Biology, University Medical Center Göttingen, Humboldtallee 23, 37073 Göttingen, Germany
- Junior Research Group Medical RNA Biology, German Primate Center, Leibniz Institute for Primate Research, Kellnerweg 4, 37077 Göttingen, Germany
| | - Rafael Rinaldi Ferreira
- Junior Research Group Medical RNA Biology, German Primate Center, Leibniz Institute for Primate Research, Kellnerweg 4, 37077 Göttingen, Germany
| | - Katherine E Bohnsack
- Department of Molecular Biology, University Medical Center Göttingen, Humboldtallee 23, 37073 Göttingen, Germany
| | - Jens Gruber
- Junior Research Group Medical RNA Biology, German Primate Center, Leibniz Institute for Primate Research, Kellnerweg 4, 37077 Göttingen, Germany
| | - Markus T Bohnsack
- Department of Molecular Biology, University Medical Center Göttingen, Humboldtallee 23, 37073 Göttingen, Germany
- Göttingen Center for Molecular Biosciences, Georg-August University, Göttingen, Justus-von-Liebig-Weg 11, 37077 Germany
- Cluster of Excellence “Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells” (MBExC)
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13
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Sexton R, Mahdi Z, Chaudhury R, Beydoun R, Aboukameel A, Khan HY, Baloglu E, Senapedis W, Landesman Y, Tesfaye A, Kim S, Philip PA, Azmi AS. Targeting Nuclear Exporter Protein XPO1/CRM1 in Gastric Cancer. Int J Mol Sci 2019; 20:E4826. [PMID: 31569391 PMCID: PMC6801932 DOI: 10.3390/ijms20194826] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 09/20/2019] [Accepted: 09/25/2019] [Indexed: 01/08/2023] Open
Abstract
Gastric cancer remains an unmet clinical problem in urgent need of newer and effective treatments. Here we show that the nuclear export protein, Exportin 1 (XPO1, chromosome region maintenance 1 or CRM1), is a promising molecular target in gastric cancer. We demonstrate significant overexpression of XPO1 in a cohort of histologically diverse gastric cancer patients with primary and metastatic disease. XPO1 RNA interference suppressed gastric cancer cell growth. Anti-tumor activity was observed with specific inhibitor of nuclear export (SINE) compounds (selinexor/XPOVIO), second-generation compound KPT-8602/eltanexor, KPT-185 and +ve control Leptomycin B in three distinct gastric cancer cell lines. SINE compounds inhibited gastric cancer cell proliferation, disrupted spheroid formation, induced apoptosis and halted cell cycle progression at the G1/S phase. Anti-tumor activity was concurrent with nuclear retention of tumor suppressor proteins and inhibition of colony formation. In combination studies, SINE compounds enhanced the efficacy of nab-paclitaxel in vitro and in vivo. More significantly, using non-coding RNA sequencing studies, we demonstrate for the first time that SINE compounds can alter the expression of non-coding RNAs (microRNAs and piwiRNAs). SINE treatment caused statistically significant downregulation of oncogenic miR-33b-3p in two distinct cell lines. These studies demonstrate the therapeutic significance of XPO1 in gastric cancer that warrants further clinical investigation.
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Affiliation(s)
- Rachel Sexton
- Department of Oncology, Wayne State University School of Medicine, Detroit, MI 48201, USA.
| | - Zaid Mahdi
- Emory Winship Cancer Institute, Atlanta, GA 30322, USA.
| | - Rahman Chaudhury
- Detroit Medical Center, Wayne State University, Detroit, MI 48201, USA.
| | - Rafic Beydoun
- Department of Pathology, Wayne State University School of Medicine, Detroit, MI 48201, USA.
| | - Amro Aboukameel
- Department of Oncology, Wayne State University School of Medicine, Detroit, MI 48201, USA.
| | - Husain Y Khan
- Department of Oncology, Wayne State University School of Medicine, Detroit, MI 48201, USA.
| | - Erkan Baloglu
- Karyopharm Therapeutics Inc., Newton, MA 02459, USA.
| | | | | | - Anteneh Tesfaye
- Department of Oncology, Wayne State University School of Medicine, Detroit, MI 48201, USA.
| | - Steve Kim
- Department of Oncology, Wayne State University School of Medicine, Detroit, MI 48201, USA.
| | - Philip A Philip
- Department of Oncology, Wayne State University School of Medicine, Detroit, MI 48201, USA.
| | - Asfar S Azmi
- Department of Oncology, Wayne State University School of Medicine, Detroit, MI 48201, USA.
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14
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Moon IY, Choi JH, Chung JW, Jang ES, Jeong SH, Kim JW. MicroRNA‑20 induces methylation of hepatitis B virus covalently closed circular DNA in human hepatoma cells. Mol Med Rep 2019; 20:2285-2293. [PMID: 31257511 PMCID: PMC6691198 DOI: 10.3892/mmr.2019.10435] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Accepted: 05/22/2019] [Indexed: 02/06/2023] Open
Abstract
Methylation was suggested to suppress the transcriptional activity of hepatitis B virus (HBV) covalently closed circular DNA (cccDNA) in hepatocytes. This may be associated with its low replicative activity during the inactive stage of chronic HBV infection; however, the exact mechanisms of methylation in HBV infection remain unknown. We have previously shown that short hairpin RNAs induced the methylation of the HBV genome in hepatoma cell lines. We also reported that the microRNA (miR) 17–92 cluster negatively regulates HBV replication in human hepatoma cells. In addition, miR-20a, a member of the miR 17–92 cluster, has sequence homology with the short hairpin RNA that induces HBV methylation. In the present study, we investigated whether miR-20a can function as an endogenous effector of HBV DNA methylation. The results indicated that overexpression of miR-20a could suppress the replicative activity of HBV and increased the degree of methylation of HBV cccDNA in the HepAD38 hepatoma cell line. Argonaute (AGO)1 and AGO2, effectors of the RNA-induced silencing complex, were detected in the nucleus of HepAD38 cells; however, only AGO2 was bound to HBV cccDNA. In addition, intranuclear AGO2 was determined to be bound with miR-20a. In conclusion, miR-20a may be loaded onto AGO2, prior to its translocation into the nucleus, inducing the methylation of HBV DNA in human hepatoma cells, leading to the suppression of HBV replication.
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Affiliation(s)
- In Young Moon
- Department of Medicine, Seoul National University Bundang Hospital, Seongnam, Gyeonggi 13620, Republic of Korea
| | - Jae Hee Choi
- Department of Medicine, Seoul National University Bundang Hospital, Seongnam, Gyeonggi 13620, Republic of Korea
| | - Jung Wha Chung
- Department of Medicine, Seoul National University Bundang Hospital, Seongnam, Gyeonggi 13620, Republic of Korea
| | - Eun Sun Jang
- Department of Medicine, Seoul National University Bundang Hospital, Seongnam, Gyeonggi 13620, Republic of Korea
| | - Sook-Hyang Jeong
- Department of Medicine, Seoul National University Bundang Hospital, Seongnam, Gyeonggi 13620, Republic of Korea
| | - Jin-Wook Kim
- Department of Medicine, Seoul National University Bundang Hospital, Seongnam, Gyeonggi 13620, Republic of Korea
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15
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The Oocyte’s Nucleolus Precursor Body: The Globe for Life. MACEDONIAN VETERINARY REVIEW 2018. [DOI: 10.2478/macvetrev-2018-0013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstract
The nucleolus is the cell organelle responsible for ribosome synthesis and, hence, for protein synthesis. In the mammalian oocyte, the nucleolus compacts into a dense sphere with no ribosome synthesis well in advance of ovulation. It seems, that this body is of utmost importance for the development of the embryo. It is unknown, however, how it exerts this essential function. During the last two decades, great attention has been paid to the study of nucleogenesis in oocytes and early embryos, with transcription of ribosomal DNA being evaluated as one of the criteria of normal development. In this review, we summarize some aspects of nucleolus transformation during oocyte growth, as well as during early embryonic development with possible impact on the quality of the embryos used in biomedical research. This knowledge in connection with further observations will substantially contribute to the development of new criteria suitable for evaluation of oocytes and embryos used in biomedical application.
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16
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Weng WH, Leung WH, Pang YJ, Kuo LW, Hsu HH. EPA significantly improves anti-EGFR targeted therapy by regulating miR-378 expression in colorectal cancer. Oncol Lett 2018; 16:6188-6194. [PMID: 30333883 DOI: 10.3892/ol.2018.9408] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 06/26/2018] [Indexed: 01/05/2023] Open
Abstract
It is known that colorectal cancer (CRC) cells containing mutations of the genes KRAS and BRAF are predominate mechanisms causing resistance to epidermal growth factor receptor (EGFR) inhibitors, and commonly exhibit a lower expression of microRNA-378 (miR-378) when compared with the wild type. In the present study, the aim was to determine the possible mechanism which associates miR-378 with the mitogen-activated protein kinase pathway, and to determine the efficiency of eicosapentaenoic acid ethyl ester (EPA) in its ability to restore sensitivity towards cetuximab, an EGFR inhibitor. The results demonstrated that a combined treatment of 40 µM EPA with 0.2 µM cetuximab can significantly suppress the cell growth in KRAS-mutant and control wild-type cells. Furthermore, the higher phosphorylated protein level of extracellular-signal-regulated kinase 1/2 was notable in KRAS EPA-treated cells (P=0.006-0.047) and resulted in significantly increased cell death; however, inconsistent results were indicated in EPA-treated BRAF-mutant cells, compared with the original cells (without treatment). KRAS-mutant and wild-type Caco-2 cells treated with EPA exhibited increased cetuximab response rates, but these response rates were reduced in the BRAF-mutant cells. In conclusion, upregulation of miR-378 induced by EPA may result in the significant restoration of sensitivity to cetuximab in the KRAS-mutant cells. The present data will contribute to a notable potential therapeutic solution for future clinical CRC treatments.
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Affiliation(s)
- Wen-Hui Weng
- Department of Chemical Engineering and Biotechnology, Graduate Institute of Biochemical and Biomedical Engineering, National Taipei University of Technology, Taipei 10608, Taiwan, R.O.C
| | - Wai-Hung Leung
- Department of Chemical Engineering and Biotechnology, Graduate Institute of Biochemical and Biomedical Engineering, National Taipei University of Technology, Taipei 10608, Taiwan, R.O.C.,Division of Colorectal Surgery, Department of Surgery, Mackay Memorial Hospital, Taipei 10491, Taiwan, R.O.C
| | - Yeu Jye Pang
- Department of Internal Medicine, Queen Elizabeth The Queen Mother Hospital, Margate CT9 4AN, UK
| | - Li-Wei Kuo
- Department of Chemical Engineering and Biotechnology, Graduate Institute of Biochemical and Biomedical Engineering, National Taipei University of Technology, Taipei 10608, Taiwan, R.O.C
| | - Hsi-Hsien Hsu
- Division of Colorectal Surgery, Department of Surgery, Mackay Memorial Hospital, Taipei 10491, Taiwan, R.O.C
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17
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Lemus-Diaz N, Tamon L, Gruber J. Dual Fluorescence Reporter Based Analytical Flow Cytometry for miRNA Induced Regulation in Mammalian Cells. Bio Protoc 2018; 8:e3000. [PMID: 34395794 DOI: 10.21769/bioprotoc.3000] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 08/14/2018] [Accepted: 08/16/2018] [Indexed: 12/21/2022] Open
Abstract
MicroRNA-induced gene regulation is a growing field in basic and translational research. Examining this regulation directly in cells is necessary to validate high-throughput data originated from RNA sequencing technologies. For this several studies employ luciferase-based reporters that usually measure the whole cell population, which comes with low resolution for the complexity of the miRNA-induced regulation. Here, we provide a protocol using a dual-fluorescence reporter and flow cytometry reaching single cell resolution; the protocol contains a simplified workflow that includes: vector generation, data acquisition, processing, and analysis using the R environment. Our protocol enables high-resolution measurements of miRNA induced post-transcriptional gene regulation and combined with system biology it can be used to estimate miRNAs proficiency.
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Affiliation(s)
- Nicolas Lemus-Diaz
- Junior Research Group Medical RNA Biology, German Primate Center, Leibniz Institute for Primate Research, Kellnerweg 4, Göttingen, Germany
| | - Liezel Tamon
- Junior Research Group Medical RNA Biology, German Primate Center, Leibniz Institute for Primate Research, Kellnerweg 4, Göttingen, Germany
| | - Jens Gruber
- Junior Research Group Medical RNA Biology, German Primate Center, Leibniz Institute for Primate Research, Kellnerweg 4, Göttingen, Germany
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18
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Naro Y, Ankenbruck N, Thomas M, Tivon Y, Connelly CM, Gardner L, Deiters A. Small Molecule Inhibition of MicroRNA miR-21 Rescues Chemosensitivity of Renal-Cell Carcinoma to Topotecan. J Med Chem 2018; 61:5900-5909. [PMID: 29993250 DOI: 10.1021/acs.jmedchem.7b01891] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Chemical probes of microRNA (miRNA) function are potential tools for understanding miRNA biology that also provide new approaches for discovering therapeutics for miRNA-associated diseases. MicroRNA-21 (miR-21) is an oncogenic miRNA that is overexpressed in most cancers and has been strongly associated with driving chemoresistance in cancers such as renal cell carcinoma (RCC). Using a cell-based luciferase reporter assay to screen small molecules, we identified a novel inhibitor of miR-21 function. Following structure-activity relationship studies, an optimized lead compound demonstrated cytotoxicity in several cancer cell lines. In a chemoresistant-RCC cell line, inhibition of miR-21 via small molecule treatment rescued the expression of tumor-suppressor proteins and sensitized cells to topotecan-induced apoptosis. This resulted in a >10-fold improvement in topotecan activity in cell viability and clonogenic assays. Overall, this work reports a novel small molecule inhibitor for perturbing miR-21 function and demonstrates an approach to enhancing the potency of chemotherapeutics specifically for cancers derived from oncomir addiction.
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Affiliation(s)
- Yuta Naro
- Department of Chemistry , University of Pittsburgh , Pittsburgh , Pennsylvania 15260 , United States
| | - Nicholas Ankenbruck
- Department of Chemistry , University of Pittsburgh , Pittsburgh , Pennsylvania 15260 , United States
| | - Meryl Thomas
- Department of Chemistry , University of Pittsburgh , Pittsburgh , Pennsylvania 15260 , United States
| | - Yaniv Tivon
- Department of Chemistry , University of Pittsburgh , Pittsburgh , Pennsylvania 15260 , United States
| | - Colleen M Connelly
- Department of Chemistry , University of Pittsburgh , Pittsburgh , Pennsylvania 15260 , United States
| | - Laura Gardner
- Department of Chemistry , University of Pittsburgh , Pittsburgh , Pennsylvania 15260 , United States
| | - Alexander Deiters
- Department of Chemistry , University of Pittsburgh , Pittsburgh , Pennsylvania 15260 , United States
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19
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Kalinina NO, Makarova S, Makhotenko A, Love AJ, Taliansky M. The Multiple Functions of the Nucleolus in Plant Development, Disease and Stress Responses. FRONTIERS IN PLANT SCIENCE 2018; 9:132. [PMID: 29479362 PMCID: PMC5811523 DOI: 10.3389/fpls.2018.00132] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 01/23/2018] [Indexed: 05/18/2023]
Abstract
The nucleolus is the most conspicuous domain in the eukaryotic cell nucleus, whose main function is ribosomal RNA (rRNA) synthesis and ribosome biogenesis. However, there is growing evidence that the nucleolus is also implicated in many other aspects of cell biology, such as regulation of cell cycle, growth and development, senescence, telomerase activity, gene silencing, responses to biotic and abiotic stresses. In the first part of the review, we briefly assess the traditional roles of the plant nucleolus in rRNA synthesis and ribosome biogenesis as well as possible functions in other RNA regulatory pathways such as splicing, nonsense-mediated mRNA decay and RNA silencing. In the second part of the review we summarize recent progress and discuss already known and new hypothetical roles of the nucleolus in plant growth and development. In addition, this part will highlight studies showing new nucleolar functions involved in responses to pathogen attack and abiotic stress. Cross-talk between the nucleolus and Cajal bodies is also discussed in the context of their association with poly(ADP ribose)polymerase (PARP), which is known to play a crucial role in various physiological processes including growth, development and responses to biotic and abiotic stresses.
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Affiliation(s)
- Natalia O. Kalinina
- Branch of the Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, Moscow, Russia
- Natalia O. Kalinina
| | - Svetlana Makarova
- Branch of the Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, Moscow, Russia
| | - Antonida Makhotenko
- Branch of the Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, Moscow, Russia
| | | | - Michael Taliansky
- Branch of the Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, Moscow, Russia
- The James Hutton Institute, Dundee, United Kingdom
- *Correspondence: Michael Taliansky
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20
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Abstract
The nucleolus is a distinct compartment of the nucleus responsible for ribosome biogenesis. Mis-regulation of nucleolar functions and of the cellular translation machinery has been associated with disease, in particular with many types of cancer. Indeed, many tumor suppressors (p53, Rb, PTEN, PICT1, BRCA1) and proto-oncogenes (MYC, NPM) play a direct role in the nucleolus, and interact with the RNA polymerase I transcription machinery and the nucleolar stress response. We have identified Dicer and the RNA interference pathway as having an essential role in the nucleolus of quiescent Schizosaccharomyces pombe cells, distinct from pericentromeric silencing, by controlling RNA polymerase I release. We propose that this novel function is evolutionarily conserved and may contribute to the tumorigenic pre-disposition of DICER1 mutations in mammals.
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Affiliation(s)
- Benjamin Roche
- a Martienssen Lab, Cold Spring Harbor Laboratory , Cold Spring Harbor , NY , USA
| | - Benoît Arcangioli
- b Genome Dynamics Unit, UMR 3525 CNRS, Institut Pasteur , Paris , France
| | - Rob Martienssen
- a Martienssen Lab, Cold Spring Harbor Laboratory , Cold Spring Harbor , NY , USA.,c Howard Hughes Medical Institute, Cold Spring Harbor Laboratory , Cold Spring Harbor , NY , USA
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21
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Paces J, Nic M, Novotny T, Svoboda P. Literature review of baseline information to support the risk assessment of RNAi‐based GM plants. ACTA ACUST UNITED AC 2017. [PMCID: PMC7163844 DOI: 10.2903/sp.efsa.2017.en-1246] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Jan Paces
- Institute of Molecular Genetics of the Academy of Sciences of the Czech Republic (IMG)
| | | | | | - Petr Svoboda
- Institute of Molecular Genetics of the Academy of Sciences of the Czech Republic (IMG)
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22
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Platelet microparticles infiltrating solid tumors transfer miRNAs that suppress tumor growth. Blood 2017; 130:567-580. [PMID: 28500171 DOI: 10.1182/blood-2016-11-751099] [Citation(s) in RCA: 161] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 05/08/2017] [Indexed: 12/13/2022] Open
Abstract
Platelet-derived microparticles (PMPs) are associated with enhancement of metastasis and poor cancer outcomes. Circulating PMPs transfer platelet microRNAs (miRNAs) to vascular cells. Solid tumor vasculature is highly permeable, allowing the possibility of PMP-tumor cell interaction. Here, we show that PMPs infiltrate solid tumors in humans and mice and transfer platelet-derived RNA, including miRNAs, to tumor cells in vivo and in vitro, resulting in tumor cell apoptosis. MiR-24 was a major species in this transfer. PMP transfusion inhibited growth of both lung and colon carcinoma ectopic tumors, whereas blockade of miR-24 in tumor cells accelerated tumor growth in vivo, and prevented tumor growth inhibition by PMPs. Conversely, Par4-deleted mice, which had reduced circulating microparticles (MPs), supported accelerated tumor growth which was halted by PMP transfusion. PMP targeting was associated with tumor cell apoptosis in vivo. We identified direct RNA targets of platelet-derived miR-24 in tumor cells, which included mitochondrial mt-Nd2, and Snora75, a noncoding small nucleolar RNA. These RNAs were suppressed in PMP-treated tumor cells, resulting in mitochondrial dysfunction and growth inhibition, in an miR-24-dependent manner. Thus, platelet-derived miRNAs transfer in vivo to tumor cells in solid tumors via infiltrating MPs, regulate tumor cell gene expression, and modulate tumor progression. These findings provide novel insight into mechanisms of horizontal RNA transfer and add multiple layers to the regulatory roles of miRNAs and PMPs in tumor progression. Plasma MP-mediated transfer of regulatory RNAs and modulation of gene expression may be a common feature with important outcomes in contexts of enhanced vascular permeability.
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23
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Dissecting miRNA gene repression on single cell level with an advanced fluorescent reporter system. Sci Rep 2017; 7:45197. [PMID: 28338079 PMCID: PMC5364550 DOI: 10.1038/srep45197] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Accepted: 02/22/2017] [Indexed: 12/16/2022] Open
Abstract
Despite major advances on miRNA profiling and target predictions, functional readouts for endogenous miRNAs are limited and frequently lead to contradicting conclusions. Numerous approaches including functional high-throughput and miRISC complex evaluations suggest that the functional miRNAome differs from the predictions based on quantitative sRNA profiling. To resolve the apparent contradiction of expression versus function, we generated and applied a fluorescence reporter gene assay enabling single cell analysis. This approach integrates and adapts a mathematical model for miRNA-driven gene repression. This model predicts three distinct miRNA-groups with unique repression activities (low, mid and high) governed not just by expression levels but also by miRNA/target-binding capability. Here, we demonstrate the feasibility of the system by applying controlled concentrations of synthetic siRNAs and in parallel, altering target-binding capability on corresponding reporter-constructs. Furthermore, we compared miRNA-profiles with the modeled predictions of 29 individual candidates. We demonstrate that expression levels only partially reflect the miRNA function, fitting to the model-projected groups of different activities. Furthermore, we demonstrate that subcellular localization of miRNAs impacts functionality. Our results imply that miRNA profiling alone cannot define their repression activity. The gene regulatory function is a dynamic and complex process beyond a minimalistic conception of "highly expressed equals high repression".
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24
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de Pauli LF, Santos EG, Daher Arcangelo FP, Orcini WA, Peruquetti RL. Differential expression of the nucleolar protein fibrillarin during mammalian spermatogenesis and its probable association with chromatoid body components. Micron 2017; 94:37-45. [DOI: 10.1016/j.micron.2016.12.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 12/12/2016] [Indexed: 10/20/2022]
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25
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Abstract
The discovery of an ever-expanding plethora of coding and non-coding RNAs with nodal and causal roles in the regulation of lung physiology and disease is reinvigorating interest in the clinical utility of the oligonucleotide therapeutic class. This is strongly supported through recent advances in nucleic acids chemistry, synthetic oligonucleotide delivery and viral gene therapy that have succeeded in bringing to market at least three nucleic acid-based drugs. As a consequence, multiple new candidates such as RNA interference modulators, antisense, and splice switching compounds are now progressing through clinical evaluation. Here, manipulation of RNA for the treatment of lung disease is explored, with emphasis on robust pharmacological evidence aligned to the five pillars of drug development: exposure to the appropriate tissue, binding to the desired molecular target, evidence of the expected mode of action, activity in the relevant patient population and commercially viable value proposition.
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26
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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: 757] [Impact Index Per Article: 94.6] [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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27
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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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28
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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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29
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Human Ribosomal RNA-Derived Resident MicroRNAs as the Transmitter of Information upon the Cytoplasmic Cancer Stress. BIOMED RESEARCH INTERNATIONAL 2016; 2016:7562085. [PMID: 27517048 PMCID: PMC4969525 DOI: 10.1155/2016/7562085] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Accepted: 06/19/2016] [Indexed: 12/13/2022]
Abstract
Dysfunction of ribosome biogenesis induces divergent ribosome-related diseases including ribosomopathy and occasionally results in carcinogenesis. Although many defects in ribosome-related genes have been investigated, little is known about contribution of ribosomal RNA (rRNA) in ribosome-related disorders. Meanwhile, microRNA (miRNA), an important regulator of gene expression, is derived from both coding and noncoding region of the genome and is implicated in various diseases. Therefore, we performed in silico analyses using M-fold, TargetScan, GeneCoDia3, and so forth to investigate RNA relationships between rRNA and miRNA against cellular stresses. We have previously shown that miRNA synergism is significantly correlated with disease and the miRNA package is implicated in memory for diseases; therefore, quantum Dynamic Nexus Score (DNS) was also calculated using MESer program. As a result, seventeen RNA sequences identical with known miRNAs were detected in the human rRNA and termed as rRNA-hosted miRNA analogs (rmiRNAs). Eleven of them were predicted to form stem-loop structures as pre-miRNAs, and especially one stem-loop was completely identical with hsa-pre-miR-3678 located in the non-rDNA region. Thus, these rmiRNAs showed significantly high DNS values, participation in regulation of cancer-related pathways, and interaction with nucleolar RNAs, suggesting that rmiRNAs may be stress-responsible resident miRNAs which transmit stress-tuning information in multiple levels.
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30
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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: 153] [Impact Index Per Article: 19.1] [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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31
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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: 134] [Impact Index Per Article: 16.8] [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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32
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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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33
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Ma TH, Lee LW, Lee CC, Yi YH, Chan SP, Tan BCM, Lo SJ. Genetic control of nucleolar size: An evolutionary perspective. Nucleus 2016; 7:112-20. [PMID: 27003693 DOI: 10.1080/19491034.2016.1166322] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
Exploiting a C. elegans mutant (ncl-1) exhibiting nucleolar abnormalities, we recently identified the let-7/ncl-1/fib-1 genetic cascade underlying proper rRNA abundance and nucleolar size. These 3 factors, let-7 (a miRNA), NCL-1 (a member of the TRIM-NHL family), and fibrillarin (a nucleolar methyltransferase), are evolutionarily conserved across metazoans. In this article, we provide several lines of bioinformatic evidence showing that human and Drosophila homologues of C. elegans NCL-1, TRIM-71 and Brat, respectively, likely act as translational suppressors of fibrillarin. Moreover, since their 3'-UTRs contain putative target sites, they may also be under the control of the let-7 miRNA. We hypothesize that let-7, TRIM and fibrillarin contribute activities in concert, and constitute a conserved network controlling nucleolar size in eukaryotes. We provide an in-depth literature review of various molecular pathways, including the let-7/ncl-1/fib-1 genetic cascade, implicated in the regulation of nucleolar size.
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Affiliation(s)
- Tian-Hsiang Ma
- a Department of Biomedical Sciences, College of Medicine , Chang Gung University , TaoYuan , Taiwan.,b Graduate Institute of Biomedical Sciences , College of Medicine , Chang Gung University , TaoYuan , Taiwan
| | - Li-Wei Lee
- a Department of Biomedical Sciences, College of Medicine , Chang Gung University , TaoYuan , Taiwan.,c Molecular Medicine Research Center , College of Medicine , Chang Gung University , TaoYuan , Taiwan
| | - Chi-Chang Lee
- d Institute of Chemistry , Academia Sinica , Taipei , Taiwan
| | - Yung-Hsiang Yi
- a Department of Biomedical Sciences, College of Medicine , Chang Gung University , TaoYuan , Taiwan.,c Molecular Medicine Research Center , College of Medicine , Chang Gung University , TaoYuan , Taiwan
| | - Shih-Peng Chan
- e Graduate Institute of Microbiology , College of Medicine , National Taiwan University , Taipei , Taiwan
| | - Bertrand Chin-Ming Tan
- a Department of Biomedical Sciences, College of Medicine , Chang Gung University , TaoYuan , Taiwan.,b Graduate Institute of Biomedical Sciences , College of Medicine , Chang Gung University , TaoYuan , Taiwan.,c Molecular Medicine Research Center , College of Medicine , Chang Gung University , TaoYuan , Taiwan
| | - Szecheng J Lo
- a Department of Biomedical Sciences, College of Medicine , Chang Gung University , TaoYuan , Taiwan.,b Graduate Institute of Biomedical Sciences , College of Medicine , Chang Gung University , TaoYuan , Taiwan.,c Molecular Medicine Research Center , College of Medicine , Chang Gung University , TaoYuan , Taiwan
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Dillinger S, Németh A. Quantitative Immunofluorescence Analysis of Nucleolus-Associated Chromatin. Methods Mol Biol 2016; 1455:59-69. [PMID: 27576710 DOI: 10.1007/978-1-4939-3792-9_5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The nuclear distribution of eu- and heterochromatin is nonrandom, heterogeneous, and dynamic, which is mirrored by specific spatiotemporal arrangements of histone posttranslational modifications (PTMs). Here we describe a semiautomated method for the analysis of histone PTM localization patterns within the mammalian nucleus using confocal laser scanning microscope images of fixed, immunofluorescence stained cells as data source. The ImageJ-based process includes the segmentation of the nucleus, furthermore measurements of total fluorescence intensities, the heterogeneity of the staining, and the frequency of the brightest pixels in the region of interest (ROI). In the presented image analysis pipeline, the perinucleolar chromatin is selected as primary ROI, and the nuclear periphery as secondary ROI.
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Affiliation(s)
- Stefan Dillinger
- Biochemistry Center Regensburg, University of Regensburg, Universitaetsstr. 31, 93053, Regensburg, Germany.
| | - Attila Németh
- Biochemistry Center Regensburg, University of Regensburg, Universitaetsstr. 31, 93053, Regensburg, Germany.
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Abstract
The nucleolus is a subcellular compartment with a key essential function in ribosome biogenesis. The nucleolus is rich in noncoding RNAs, mostly the ribosomal RNAs and small nucleolar RNAs. Surprisingly, also several miRNAs have been detected in the nucleolus, raising the question as to whether other small RNA species are present and functional in the nucleolus. We have developed a strategy for stepwise enrichment of nucleolar small RNAs from the total nucleolar RNA extracts and subsequent construction of nucleolar small RNA libraries which are suitable for deep sequencing. Our method successfully isolates the small RNA population from total RNAs and monitors the RNA quality in each step to ensure that small RNAs recovered represent the actual small RNA population in the nucleolus and not degradation products from larger RNAs. We have further applied this approach to characterize the distribution of small RNAs in different cellular compartments.
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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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Ono M, Yamada K, Avolio F, Afzal V, Bensaddek D, Lamond AI. Targeted Knock-Down of miR21 Primary Transcripts Using snoMEN Vectors Induces Apoptosis in Human Cancer Cell Lines. PLoS One 2015; 10:e0138668. [PMID: 26405811 PMCID: PMC4583369 DOI: 10.1371/journal.pone.0138668] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 09/02/2015] [Indexed: 11/18/2022] Open
Abstract
We have previously reported an antisense technology, 'snoMEN vectors', for targeted knock-down of protein coding mRNAs using human snoRNAs manipulated to contain short regions of sequence complementarity with the mRNA target. Here we characterise the use of snoMEN vectors to target the knock-down of micro RNA primary transcripts. We document the specific knock-down of miR21 in HeLa cells using plasmid vectors expressing miR21-targeted snoMEN RNAs and show this induces apoptosis. Knock-down is dependent on the presence of complementary sequences in the snoMEN vector and the induction of apoptosis can be suppressed by over-expression of miR21. Furthermore, we have also developed lentiviral vectors for delivery of snoMEN RNAs and show this increases the efficiency of vector transduction in many human cell lines that are difficult to transfect with plasmid vectors. Transduction of lentiviral vectors expressing snoMEN targeted to pri-miR21 induces apoptosis in human lung adenocarcinoma cells, which express high levels of miR21, but not in human primary cells. We show that snoMEN-mediated suppression of miRNA expression is prevented by siRNA knock-down of Ago2, but not by knock-down of Ago1 or Upf1. snoMEN RNAs colocalise with Ago2 in cell nuclei and nucleoli and can be co-immunoprecipitated from nuclear extracts by antibodies specific for Ago2.
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Affiliation(s)
- Motoharu Ono
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Kayo Yamada
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Fabio Avolio
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Vackar Afzal
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Dalila Bensaddek
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Angus I. Lamond
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
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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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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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Hoogstrate Y, Jenster G, Martens-Uzunova ES. FlaiMapper: computational annotation of small ncRNA-derived fragments using RNA-seq high-throughput data. Bioinformatics 2014; 31:665-73. [PMID: 25338717 DOI: 10.1093/bioinformatics/btu696] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
MOTIVATION Recent discoveries show that most types of small non-coding RNAs (sncRNAs) such as miRNAs, snoRNAs and tRNAs get further processed into putatively active smaller RNA species. Their roles, genetic profiles and underlying processing mechanisms are only partially understood. To find their quantities and characteristics, a proper annotation is essential. Here, we present FlaiMapper, a method that extracts and annotates the locations of sncRNA-derived RNAs (sncdRNAs). These sncdRNAs are often detected in sequencing data and observed as fragments of their precursor sncRNA. Using small RNA-seq read alignments, FlaiMapper is able to annotate fragments primarily by peak detection on the start and end position densities followed by filtering and a reconstruction process. RESULTS To assess performance of FlaiMapper, we used independent publicly available small RNA-seq data. We were able to detect fragments representing putative sncdRNAs from nearly all types of sncRNA, including 97.8% of the annotated miRNAs in miRBase that have supporting reads. Comparison of FlaiMapper-predicted boundaries of miRNAs with miRBase entries demonstrated that 89% of the start and 54% of the end positions are identical. Additional benchmarking showed that FlaiMapper is superior in performance compared with existing software. Further analysis indicated a variety of characteristics in the fragments, including sequence motifs and relations with RNA interacting factors. These characteristics set a good basis for further research on sncdRNAs. AVAILABILITY AND IMPLEMENTATION The platform independent GPL licensed Python 2.7 code is available at: https://github.com/yhoogstrate/flaimapper.
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Affiliation(s)
- Youri Hoogstrate
- Department of Urology, Erasmus University Medical Center, Be 362a, PO Box 2040, 3000 CA Rotterdam, The Netherlands
| | - Guido Jenster
- Department of Urology, Erasmus University Medical Center, Be 362a, PO Box 2040, 3000 CA Rotterdam, The Netherlands
| | - Elena S Martens-Uzunova
- Department of Urology, Erasmus University Medical Center, Be 362a, PO Box 2040, 3000 CA Rotterdam, The Netherlands
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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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