1
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Zhang H, Wang H, An Y, Chen Z. Construction and application of adenoviral vectors. MOLECULAR THERAPY. NUCLEIC ACIDS 2023; 34:102027. [PMID: 37808925 PMCID: PMC10556817 DOI: 10.1016/j.omtn.2023.09.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
Adenoviral vectors have been widely used as vaccine candidates or potential vaccine candidates against infectious diseases due to the convenience of genome manipulation, their ability to accommodate large exogenous gene fragments, easy access of obtaining high-titer of virus, and high efficiency of transduction. At the same time, adenoviral vectors have also been used extensively in clinical research for cancer gene therapy and treatment of diseases caused by a single gene defect. However, application of adenovirus also faces a series of challenges such as poor targeting, strong immune response against the vector itself, and they cannot be used repeatedly. It is believed that these problems will be solved gradually with further research and technological development in related fields. Here, we review the construction methods of adenoviral vectors, including "gutless" adenovirus and discuss application of adenoviral vectors as prophylactic vaccines for infectious pathogens and their application prospects as therapeutic vaccines for cancer and other kinds of chronic infectious disease such as human papillomavirus, hepatitis B virus, and hepatitis C virus.
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Affiliation(s)
- Hongbo Zhang
- Department of Basic Research, Ab&B Bio-Tech CO., LTD. JS, Taizhou, Jiangsu, China
| | - Hongdan Wang
- Department of Basic Research, Ab&B Bio-Tech CO., LTD. JS, Taizhou, Jiangsu, China
| | - Youcai An
- Department of Basic Research, Ab&B Bio-Tech CO., LTD. JS, Taizhou, Jiangsu, China
| | - Ze Chen
- Department of Basic Research, Ab&B Bio-Tech CO., LTD. JS, Taizhou, Jiangsu, China
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2
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Yang M, Zhang Y, Li M, Liu X, Darvishi M. The various role of microRNAs in breast cancer angiogenesis, with a special focus on novel miRNA-based delivery strategies. Cancer Cell Int 2023; 23:24. [PMID: 36765409 PMCID: PMC9912632 DOI: 10.1186/s12935-022-02837-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 12/20/2022] [Indexed: 02/12/2023] Open
Abstract
After skin malignancy, breast cancer is the most widely recognized cancer detected in women in the United States. Breast cancer (BCa) can happen in all kinds of people, but it's much more common in women. One in four cases of cancer and one in six deaths due to cancer are related to breast cancer. Angiogenesis is an essential factor in the growth of tumors and metastases in various malignancies. An expanded level of angiogenesis is related to diminished endurance in BCa patients. This function assumes a fundamental part inside the human body, from the beginning phases of life to dangerous malignancy. Various factors, referred to as angiogenic factors, work to make a new capillary. Expanding proof demonstrates that angiogenesis is managed by microRNAs (miRNAs), which are small non-coding RNA with 19-25 nucleotides. MiRNA is a post-transcriptional regulator of gene expression that controls many critical biological processes. Endothelial miRNAs, referred to as angiomiRs, are probably concerned with tumor improvement and angiogenesis via regulation of pro-and anti-angiogenic factors. In this article, we reviewed therapeutic functions of miRNAs in BCa angiogenesis, several novel delivery carriers for miRNA-based therapeutics, as well as CRISPR/Cas9 as a targeted therapy in breast cancer.
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Affiliation(s)
- Min Yang
- College of Traditional Chinese Medicine, Jilin Agricultural Science and Technology University, Jilin, 132101 China
| | - Ying Zhang
- College of Traditional Chinese Medicine, Jilin Agricultural Science and Technology University, Jilin, 132101 China
| | - Min Li
- College of Traditional Chinese Medicine, Jilin Agricultural Science and Technology University, Jilin, 132101 China
| | - Xinglong Liu
- College of Traditional Chinese Medicine, Jilin Agricultural Science and Technology University, Jilin, 132101 China
| | - Mohammad Darvishi
- Infectious Diseases and Tropical Medicine Research Center (IDTMRC), Department of Aerospace and Subaquatic Medicine, AJA University of Medical Sciences, Tehran, Iran
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3
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MicroRNAs in T Cell-Immunotherapy. Int J Mol Sci 2022; 24:ijms24010250. [PMID: 36613706 PMCID: PMC9820302 DOI: 10.3390/ijms24010250] [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: 11/11/2022] [Revised: 12/06/2022] [Accepted: 12/15/2022] [Indexed: 12/28/2022] Open
Abstract
MicroRNAs (miRNAs) act as master regulators of gene expression in homeostasis and disease. Despite the rapidly growing body of evidence on the theranostic potential of restoring miRNA levels in pre-clinical models, the translation into clinics remains limited. Here, we review the current knowledge of miRNAs as T-cell targeting immunotherapeutic tools, and we offer an overview of the recent advances in miRNA delivery strategies, clinical trials and future perspectives in RNA interference technologies.
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4
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Pouya FD, Rasmi Y, Gazouli M, Zografos E, Nemati M. MicroRNAs as therapeutic targets in breast cancer metastasis. Drug Deliv Transl Res 2022; 12:1029-1046. [PMID: 33987801 DOI: 10.1007/s13346-021-00999-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/29/2021] [Indexed: 12/24/2022]
Abstract
Breast cancer is a complex disease with multiple risk factors involved in its pathogenesis. Among these factors, microRNAs are considered for playing a fundamental role in the development and progression of malignant breast tumors. In recent years, various studies have demonstrated that several microRNAs exhibit increased or decreased expression in metastatic breast cancer, acting as indicators of metastatic potential in body fluids and tissue samples. The identification of these microRNA expression patterns could prove instrumental for the development of novel therapeutic molecules that either mimic or inhibit microRNA action. Additionally, an efficient delivery system mediated by viral vectors, nonviral carriers, or scaffold biomaterials is a prerequisite for implementing microRNA-based therapies; therefore, this review attempts to highlight essential microRNA molecules involved in the metastatic process of breast cancer and discuss recent advances in microRNA-based therapeutic approaches with potential future applications to the treatment sequence of breast cancer.
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Affiliation(s)
- Fahima Danesh Pouya
- Department of Biochemistry, School of Medicine, Urmia University of Medical Sciences, Urmia, Iran
| | - Yousef Rasmi
- Department of Biochemistry, School of Medicine, Urmia University of Medical Sciences, Urmia, Iran.
- Cellular and Molecular Research Center, Urmia University of Medical Sciences, Urmia, Iran.
| | - Maria Gazouli
- Laboratory of Biology, Medical School, National and Kapodistrian University of Athens, 11527, Athens, Greece
| | - Eleni Zografos
- Laboratory of Biology, Medical School, National and Kapodistrian University of Athens, 11527, Athens, Greece
| | - Mohadeseh Nemati
- Department of Biochemistry, School of Medicine, Urmia University of Medical Sciences, Urmia, Iran
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5
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Grixti JM, Ayers D, Day PJR. An Analysis of Mechanisms for Cellular Uptake of miRNAs to Enhance Drug Delivery and Efficacy in Cancer Chemoresistance. Noncoding RNA 2021; 7:27. [PMID: 33923485 PMCID: PMC8167612 DOI: 10.3390/ncrna7020027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 04/11/2021] [Accepted: 04/13/2021] [Indexed: 12/15/2022] Open
Abstract
Up until recently, it was believed that pharmaceutical drugs and their metabolites enter into the cell to gain access to their targets via simple diffusion across the hydrophobic lipid cellular membrane, at a rate which is based on their lipophilicity. An increasing amount of evidence indicates that the phospholipid bilayer-mediated drug diffusion is in fact negligible, and that drugs pass through cell membranes via proteinaceous membrane transporters or carriers which are normally used for the transportation of nutrients and intermediate metabolites. Drugs can be targeted to specific cells and tissues which express the relevant transporters, leading to the design of safe and efficacious treatments. Furthermore, transporter expression levels can be manipulated, systematically and in a high-throughput manner, allowing for considerable progress in determining which transporters are used by specific drugs. The ever-expanding field of miRNA therapeutics is not without its challenges, with the most notable one being the safe and effective delivery of the miRNA mimic/antagonist safely to the target cell cytoplasm for attaining the desired clinical outcome, particularly in miRNA-based cancer therapeutics, due to the poor efficiency of neo-vascular systems revolting around the tumour site, brought about by tumour-induced angiogenesis. This acquisition of resistance to several types of anticancer drugs can be as a result of an upregulation of efflux transporters expression, which eject drugs from cells, hence lowering drug efficacy, resulting in multidrug resistance. In this article, the latest available data on human microRNAs has been reviewed, together with the most recently described mechanisms for miRNA uptake in cells, for future therapeutic enhancements against cancer chemoresistance.
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Affiliation(s)
- Justine M. Grixti
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, Biosciences Building, University of Liverpool, Liverpool L69 7ZB, UK;
| | - Duncan Ayers
- Centre for Molecular Medicine and Biobanking, University of Malta, Msida MSD 2080, Malta
- Faculty of Biology, Medicine and Human Sciences, The University of Manchester, Manchester M1 7DN, UK;
| | - Philip J. R. Day
- Faculty of Biology, Medicine and Human Sciences, The University of Manchester, Manchester M1 7DN, UK;
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6
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Zhang X, Li H, Mao M, Wang X, Zheng J, Yang S. Mitotically-associated long non-coding RNA promotes cancer cell proliferation in hepatocellular carcinoma by downregulating miR-122a. Oncol Lett 2019; 18:6237-6242. [PMID: 31788100 DOI: 10.3892/ol.2019.10947] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Accepted: 07/05/2019] [Indexed: 01/16/2023] Open
Abstract
Mitotically-associated long non-coding RNA (MANCR) is involved in malignant breast cancer. The present study analyzed the role of MANCR in hepatocellular carcinoma (HCC). MANCR was found to be upregulated in HCC and high expression level of MANCR in cancer tissues predicted poor survival of HCC patients. MicroRNA (miR)-122a was downregulated HCC and was inversely correlated with MANCR only in cancer tissues. MANCR overexpression resulted in downregulation of miR-122a, while miR-122a overexpression showed no obvious effects on MANCR expression. MANCR overexpression showed no significant effects on HCC cell proliferation but led to promoted cell migration and invasion. miR-122a overexpression led to inhibited migration and invasion of HCC cells and attenuated the effects of MANCR overexpression. Therefore, lncRNA MANCR may promote cancer cell proliferation in HCC by downregulating miR-122a.
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Affiliation(s)
- Xuejing Zhang
- Department of Medical Ultrasonics, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430014, P.R. China
| | - Hongling Li
- Department of Medical Ultrasonics, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430014, P.R. China
| | - Mingfeng Mao
- Department of Medical Ultrasonics, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430014, P.R. China
| | - Xiangyang Wang
- Department of Gastrointestinal Surgery, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430014, P.R. China
| | - Jingjing Zheng
- Department of Medical Ultrasonics, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430014, P.R. China
| | - Shunshi Yang
- Department of Medical Ultrasonics, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430014, P.R. China
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7
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Enhanced Tailored MicroRNA Sponge Activity of RNA Pol II-Transcribed TuD Hairpins Relative to Ectopically Expressed ciRS7-Derived circRNAs. MOLECULAR THERAPY. NUCLEIC ACIDS 2018; 13:365-375. [PMID: 30347350 PMCID: PMC6198105 DOI: 10.1016/j.omtn.2018.09.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 09/17/2018] [Accepted: 09/17/2018] [Indexed: 12/30/2022]
Abstract
As key regulators of gene expression, microRNAs (miRNAs) have emerged as targets in basic experimentation and therapy. Administration of DNA-encoded RNA molecules, targeting miRNAs through base pairing, is one viable strategy for inhibiting specific miRNAs. A naturally occurring circular RNA (circRNA), ciRS-7, serving as a miRNA-7 (miR-7) sponge was recently identified. This has sparked tremendous interest in adapting circRNAs for suppressing miRNA function. In parallel, we and others have demonstrated efficacy of expressed anti-miRNA Tough Decoy (TuD) hairpins. To compare properties of such inhibitors, we express ciRS-7 and TuD-containing miRNA suppressor transcripts from identical vector formats adapted from RNA polymerase II-directed expression plasmids previously used for production of ciRS-7. In general, markedly higher levels of miR-7 suppression with TuD transcripts relative to ciRS-7 are observed, leading to superior miRNA sponge effects using expressed TuD hairpins. Notably however, we find that individual ciRS-7 transcripts are more potent inhibitors of miR-7 activity than individual TuD7-containing transcripts, although each miR-7 seed match target site in ciRS-7 is, on average, less potent than the perfectly matched target sites in the TuD motif. All together, our studies call for improved means of designing and producing circRNAs for customized miRNA targeting to match TuD hairpins for tailored miRNA suppression.
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8
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Herrera-Carrillo E, Liu YP, Berkhout B. Improving miRNA Delivery by Optimizing miRNA Expression Cassettes in Diverse Virus Vectors. Hum Gene Ther Methods 2018; 28:177-190. [PMID: 28712309 DOI: 10.1089/hgtb.2017.036] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The RNA interference pathway is an evolutionary conserved post-transcriptional gene regulation mechanism that is exclusively triggered by double-stranded RNA inducers. RNAi-based methods and technologies have facilitated the discovery of many basic science findings and spurred the development of novel RNA therapeutics. Transient induction of RNAi via transfection of synthetic small interfering RNAs can trigger the selective knockdown of a target mRNA. For durable silencing of gene expression, either artificial short hairpin RNA or microRNA encoding transgene constructs were developed. These miRNAs are based on the molecules that induce the natural RNAi pathway in mammals and humans: the endogenously expressed miRNAs. Significant efforts focused on the construction and delivery of miRNA cassettes in order to solve basic biology questions or to design new therapy strategies. Several viral vectors have been developed, which are particularly useful for the delivery of miRNA expression cassettes to specific target cells. Each vector system has its own unique set of distinct properties. Thus, depending on the specific application, a particular vector may be most suitable. This field was previously reviewed for different viral vector systems, and now the recent progress in the field of miRNA-based gene-silencing approaches using lentiviral vectors is reported. The focus is on the unique properties and respective limitations of the available vector systems for miRNA delivery.
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Affiliation(s)
- Elena Herrera-Carrillo
- Laboratory of Experimental Virology, Department of Medical Microbiology, Academic Medical Center, University of Amsterdam , Amsterdam, The Netherlands
| | - Ying Poi Liu
- Laboratory of Experimental Virology, Department of Medical Microbiology, Academic Medical Center, University of Amsterdam , Amsterdam, The Netherlands
| | - Ben Berkhout
- Laboratory of Experimental Virology, Department of Medical Microbiology, Academic Medical Center, University of Amsterdam , Amsterdam, The Netherlands
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9
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Hollensen AK, Thomsen R, Bak RO, Petersen CC, Ermegaard ER, Aagaard L, Damgaard CK, Mikkelsen JG. Improved microRNA suppression by WPRE-linked tough decoy microRNA sponges. RNA (NEW YORK, N.Y.) 2017; 23:1247-1258. [PMID: 28487381 PMCID: PMC5513069 DOI: 10.1261/rna.061192.117] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 04/26/2017] [Indexed: 05/02/2023]
Abstract
Our genes are post-transcriptionally regulated by microRNAs (miRNAs) inducing translational suppression and degradation of targeted mRNAs. Strategies to inhibit miRNAs in a spatiotemporal manner in a desired cell type or tissue, or at a desired developmental stage, can be crucial for understanding miRNA function and for pushing forward miRNA suppression as a feasible rationale for genetic treatment of disease. For such purposes, RNA polymerase II (RNA Pol II)-transcribed tough decoy (TuD) miRNA inhibitors are particularly attractive. Here, we demonstrate augmented miRNA suppression capacity of TuD RNA hairpins linked to the Woodchuck hepatitis virus post-transcriptional regulatory element (WPRE). This effect is position-dependent and evident only when the WPRE is positioned upstream of the TuD. In accordance, inclusion of the WPRE does not change nuclear export, translation, total levels of TuD-containing RNA transcripts, or cytoplasmic P-body localization, suggesting that previously reported WPRE functions are negligible for improved TuD function. Notably, deletion analysis of TuD-fused WPRE unveils truncated WPRE variants resulting in optimized miRNA suppression. Together, our findings add to the guidelines for production of WPRE-supported anti-miRNA TuDs.
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Affiliation(s)
- Anne Kruse Hollensen
- Department of Biomedicine, HEALTH, Aarhus University, DK-8000 Aarhus C, Denmark
- Department of Molecular Biology and Genetics, Science and Technology, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Rune Thomsen
- Department of Molecular Biology and Genetics, Science and Technology, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Rasmus O Bak
- Department of Biomedicine, HEALTH, Aarhus University, DK-8000 Aarhus C, Denmark
- Department of Pediatrics, Stanford University, Stanford, California 94305, USA
| | | | - Eva R Ermegaard
- Department of Biomedicine, HEALTH, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Lars Aagaard
- Department of Biomedicine, HEALTH, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Christian Kroun Damgaard
- Department of Molecular Biology and Genetics, Science and Technology, Aarhus University, DK-8000 Aarhus C, Denmark
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10
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Inhibiting miR-21 attenuates experimental hepatic fibrosis by suppressing both the ERK1 pathway in HSC and hepatocyte EMT. Clin Sci (Lond) 2016; 130:1469-80. [PMID: 27226339 DOI: 10.1042/cs20160334] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 05/25/2016] [Indexed: 12/15/2022]
Abstract
MicroRNA-21 (miR-21) has emerged as a critical regulatory molecule and an important serum marker in hepatic fibrogenesis. The aim of the present study was to investigate the role of inhibiting miR-21 on hepatic fibrosis treatment. Serum miR-21 levels in 60 healthy individuals and 180 patients with different stages of liver cirrhosis were examined, miR-21 levels in normal or cirrhotic human liver tissues (n=10 each) were also detected. An adenoviral vector (Ad-TuD-21) carrying the sponging ToughDecoy (TuD)-RNA sequence against miR-21 was constructed to reduce miR-21 expression efficiently in vitro and in vivo Histological and immunohistological examinations were performed to evaluate the inhibitory effects and mechanism of Ad-TuD-21 delivery into carbon tetrachloride (CCl4) induced hepatic fibrosis rats by targeting extracellular signal-regulated kinase 1 (ERK1) signalling in hepatic stellate cells (HSC) and hepatocyte epithelial-mesenchymal transition (EMT). Our results revealed that enhanced miR-21 levels in cirrhotic patients were related to the severity and activity of liver cirrhosis. Ad-TuD-21 administered to liver fibrosis rats could remarkably suppress profibrotic gene expression, cause histological improvements in liver and attenuate hepatic fibrosis significantly. More importantly, after Ad-TuD-21 treatment, inhibition of both the ERK1 signalling pathway in HSC and hepatocyte EMT was confirmed, which paralleled the enhancement of miR-21 target genes-sprouty2 (SPRY2) and hepatocyte nuclear factor 4α (HNF4α)-expression in vivo These data demonstrated that miR-21 is a key regulator to promote hepatic fibrogenesis, and sponging miR-21 expression may present a novel potentially therapeutic option for hepatic fibrosis.
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11
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12
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Noncoding oligonucleotides: the belle of the ball in gene therapy. ADVANCES IN GENETICS 2014; 89:153-177. [PMID: 25620011 DOI: 10.1016/bs.adgen.2014.10.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Gene therapy carries the promise of cures for many diseases based on manipulating the expression of a person's genes toward the therapeutic goal. The relevance of noncoding oligonucleotides to human disease is attracting widespread attention. Noncoding oligonucleotides are not only involved in gene regulation, but can also be modified into therapeutic tools. There are many strategies that leverage noncoding oligonucleotides for gene therapy, including small interfering RNAs, antisense oligonucleotides, aptamers, ribozymes, decoys, and bacteriophage phi 29 RNAs. In this chapter, we will provide a broad, comprehensive overview of gene therapies that use noncoding oligonucleotides for disease treatment. The mechanism and development of each therapeutic will be described, with a particular focus on its clinical development. Finally, we will discuss the challenges associated with developing nucleic acid therapeutics and the prospects for future success.
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13
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Bak RO, Mikkelsen JG. miRNA sponges: soaking up miRNAs for regulation of gene expression. WILEY INTERDISCIPLINARY REVIEWS-RNA 2013; 5:317-33. [PMID: 24375960 DOI: 10.1002/wrna.1213] [Citation(s) in RCA: 164] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Revised: 09/12/2013] [Accepted: 09/13/2013] [Indexed: 12/17/2022]
Abstract
MicroRNAs (miRNAs) are small regulatory RNAs that act in an entangled web of interactions with target mRNAs to shape the cellular protein landscape by post-transcriptional control of mRNA decay and translation. miRNAs are themselves subject to numerous regulatory mechanisms that adjust their prevalence and activity. Emerging evidence suggests that miRNAs are themselves targeted by regulatory RNA species, and the identification of several classes of noncoding RNA molecules carrying miRNA binding sites has added a new intricate dimension to miRNA regulation. Such miRNA 'sponges' bind miRNAs and competitively sequester them from their natural targets. Endogenous miRNA sponges, also termed competing endogenous RNAs (ceRNAs), act to buffer the activity of miRNAs on physiologically relevant targets. This class of sponges includes endogenously transcribed pseudogenes, long noncoding RNAs, and recently discovered circular RNAs and may act in large complex networks in conjunction with miRNAs to regulate the output of protein. With the growing demand of regulating miRNA activity for experimental purposes and potential future clinical use, naturally occurring miRNA sponges are providing inspiration for engineering of gene vector-encoded sponges as potent inhibitors of miRNA activity. Combined with potent and versatile vector technologies, expression of custom-designed sponges provides new means of managing miRNAs and soaking up miRNAs for therapeutic regulation of gene expression.
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Affiliation(s)
- Rasmus O Bak
- Department of Biomedicine, Aarhus University, Aarhus C, Denmark
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14
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Bak RO, Hollensen AK, Mikkelsen JG. Managing microRNAs with vector-encoded decoy-type inhibitors. Mol Ther 2013; 21:1478-85. [PMID: 23752312 DOI: 10.1038/mt.2013.113] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Accepted: 04/26/2013] [Indexed: 01/16/2023] Open
Abstract
A rapidly growing understanding of the complex circuitry of microRNA (miRNA)-mediated gene regulation is attracting attention to miRNAs as new drug targets. Targeted miRNA suppression is achieved in a sequence-specific manner by antisense RNA "decoy" molecules. Such synthetic miRNA inhibitors have reached the clinic with remarkable pace and may soon appear as new therapeutic modalities in several diseases. Shortcomings, however, include high production costs, the requirement for repeated administration, and difficulty achieving tissue-specific delivery. With the many recent landmark achievements in clinical gene therapy, new and refined vector-encoded miRNA suppression technologies are attractive for many applications, not least as tools in innumerable daily studies of miRNA biology in laboratories worldwide. Here, we provide an overview of the strategies that have been used to adapt vector-encoded inhibitors for miRNA suppression and discuss advantages related to spatiotemporal and long-term miRNA attenuation. With the remarkable new discovery of miRNA management by naturally occurring circular RNAs, RNA circles generated by trans-splicing mechanisms may prove to be well-suited carriers of decoy-type miRNA inhibitors. The community will aspire to combine circles with high-affinity miRNA decoy methodologies, and such "vectorized" RNA circles may represent new solid ways to deliver miRNA inhibitors, perhaps even with therapeutic applications.
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Affiliation(s)
- Rasmus O Bak
- Department of Biomedicine, Aarhus University, DK-8000 Aarhus C, Denmark
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15
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Uchino K, Ochiya T, Takeshita F. RNAi therapeutics and applications of microRNAs in cancer treatment. Jpn J Clin Oncol 2013; 43:596-607. [PMID: 23592885 DOI: 10.1093/jjco/hyt052] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
RNA interference-based therapies are proving to be powerful tools for combating various diseases, including cancer. Scientists are researching the development of safe and efficient systems for the delivery of small RNA molecules, which are extremely fragile in serum, to target organs and cells in the human body. A dozen pre-clinical and clinical trials have been under way over the past few years involving biodegradable nanoparticles, lipids, chemical modification and conjugation. On the other hand, microRNAs, which control the balance of cellular biological processes, have been studied as attractive therapeutic targets in cancer treatment. In this review, we provide an overview of RNA interference-based therapeutics in clinical trials and discuss the latest technology for the systemic delivery of nucleic acid drugs. Furthermore, we focus on dysregulated microRNAs in human cancer, which have progressed in pre-clinical trials as therapeutic targets, and describe a wide range of strategies to control the expression levels of endogenous microRNAs. Further development of RNA interference technologies and progression of clinical trials will contribute to the achievement of practical applications of nucleic acid drugs.
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Affiliation(s)
- Keita Uchino
- Division of Molecular and Cellular Medicine, National Cancer Center Research Institute, 1-1, Tsukiji 5-chome, Chuo-ku, Tokyo 104-0045, Japan
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16
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Bak RO, Hollensen AK, Primo MN, Sørensen CD, Mikkelsen JG. Potent microRNA suppression by RNA Pol II-transcribed 'Tough Decoy' inhibitors. RNA (NEW YORK, N.Y.) 2013; 19:280-93. [PMID: 23249752 PMCID: PMC3543086 DOI: 10.1261/rna.034850.112] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Accepted: 11/09/2012] [Indexed: 05/13/2023]
Abstract
MicroRNAs (miRNAs) are key regulators of gene expression and modulators of diverse biological pathways. Analyses of miRNA function as well as therapeutic managing of miRNAs rely on cellular administration of miRNA inhibitors which may be achieved by the use of viral vehicles. This study explores the miRNA-suppressive capacity of inhibitors expressed intracellularly from lentivirus-derived gene vectors. Superior activity of two decoy-type inhibitors, a "Bulged Sponge" with eight miRNA recognition sites and a hairpin-shaped "Tough Decoy" containing two miRNA recognition sites, is demonstrated in a side-by-side comparison of seven types of miRNA inhibitors transcribed as short RNAs from an RNA Pol III promoter. We find that lentiviral vectors expressing Tough Decoy inhibitors are less vulnerable than Bulged Sponge-encoding vectors to targeting by the cognate miRNA and less prone, therefore, to reductions in transfer efficiency. Importantly, it is demonstrated that Tough Decoy inhibitors retain their miRNA suppression capacity in the context of longer RNA transcripts expressed from an RNA Pol II promoter. Such RNA Pol II-transcribed Tough Decoy inhibitors are new tools in managing of miRNAs and may have potential for temporal and spatial regulation of miRNA activity as well as for therapeutic targeting of miRNAs that are aberrantly expressed in human disease.
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