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Zhan Y, Cao C, Li A, Mei H, Liu Y. Enhanced RNA knockdown efficiency with engineered fusion guide RNAs that function with both CRISPR-CasRx and hammerhead ribozyme. Genome Biol 2023; 24:9. [PMID: 36650600 PMCID: PMC9843992 DOI: 10.1186/s13059-023-02852-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 01/06/2023] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND CRISPR-Cas13 is a newly emerging RNA knockdown technology that is comparable to RNAi. Among all members of Cas13, CasRx degrades RNA in human cells with high precision and effectiveness. However, it remains unclear whether the efficiency of this technology can be further improved and applied to gene therapy. RESULTS In this study, we fuse CasRx crRNA with an antisense ribozyme to construct a synthetic fusion guide RNA that can interact with both CasRx protein and ribozyme and tested the ability of this approach in RNA knockdown and cancer gene therapy. We show that the CasRx-crRNA-ribozyme system (CCRS) is more efficient for RNA knockdown of mRNAs and non-coding RNAs than conventional methods, including CasRx, shRNA, and ribozyme. In particular, CCRS is more effective than wild-type CasRx when targeting multiple transcripts simultaneously. We next use bladder cancer as a model to evaluate the anticancer effects of CCRS targeting multiple genes in vitro and in vivo. CCRS shows a higher anticancer effect than conventional methods, consistent with the gene knockdown results. CONCLUSIONS Thus, our study demonstrates that CCRS expands the design ideas and RNA knockdown capabilities of Cas13 technology and has the potential to be used in disease treatment.
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Affiliation(s)
- Yonghao Zhan
- grid.263488.30000 0001 0472 9649Shenzhen Institute of Translational Medicine, Shenzhen Second People’s Hospital, The First Affiliated Hospital of Shenzhen University, Health Science Center, Shenzhen University, Shenzhen, 518035 China ,grid.412633.10000 0004 1799 0733Department of Urology, The First Affiliated Hospital of Zhengzhou University, No. 1 Jianshe East Road, Zhengzhou, 450052 China
| | - Congcong Cao
- grid.263488.30000 0001 0472 9649Shenzhen Institute of Translational Medicine, Shenzhen Second People’s Hospital, The First Affiliated Hospital of Shenzhen University, Health Science Center, Shenzhen University, Shenzhen, 518035 China ,grid.9227.e0000000119573309Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055 China
| | - Aolin Li
- grid.263488.30000 0001 0472 9649Shenzhen Institute of Translational Medicine, Shenzhen Second People’s Hospital, The First Affiliated Hospital of Shenzhen University, Health Science Center, Shenzhen University, Shenzhen, 518035 China ,grid.263488.30000 0001 0472 9649Department of Urology, Shenzhen Second People’s Hospital, The First Affiliated Hospital of Shenzhen University, International Cancer Center, Shenzhen University School of Medicine, Shenzhen, 518035 China
| | - Hongbing Mei
- grid.263488.30000 0001 0472 9649Department of Urology, Shenzhen Second People’s Hospital, The First Affiliated Hospital of Shenzhen University, International Cancer Center, Shenzhen University School of Medicine, Shenzhen, 518035 China
| | - Yuchen Liu
- grid.263488.30000 0001 0472 9649Shenzhen Institute of Translational Medicine, Shenzhen Second People’s Hospital, The First Affiliated Hospital of Shenzhen University, Health Science Center, Shenzhen University, Shenzhen, 518035 China
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Cell-Based Double-Screening Method to Identify a Reliable Candidate for Osteogenesis-Targeting Compounds. Biomedicines 2022; 10:biomedicines10020426. [PMID: 35203635 PMCID: PMC8962348 DOI: 10.3390/biomedicines10020426] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2022] [Revised: 02/05/2022] [Accepted: 02/07/2022] [Indexed: 01/15/2023] Open
Abstract
Small-molecule compounds strongly affecting osteogenesis can form the basis of effective therapeutic strategies in bone regenerative medicine. A cell-based high-throughput screening system might be a powerful tool for identifying osteoblast-targeting candidates; however, this approach is generally limited with using only one molecule as a cell-based sensor that does not always reflect the activation of the osteogenic phenotype. In the present study, we used the MC3T3-E1 cell line stably transfected with the green fluorescent protein (GFP) reporter gene driven by a fragment of type I collagen promoter (Col-1a1GFP-MC3T3-E1) to evaluate a double-screening system to identify osteogenic inducible compounds using a combination of a cell-based reporter assay and detection of alkaline phosphatase (ALP) activity. Col-1a1GFP-MC3T3-E1 cells were cultured in an osteogenic induction medium after library screening of 1280 pharmacologically active compounds (Lopack1280). After 7 days, GFP fluorescence was measured using a microplate reader. After 14 days of osteogenic induction, the cells were stained with ALP. Library screening using the Col-1a1/GFP reporter and ALP staining assay detected three candidates with significant osteogenic induction ability. Furthermore, leflunomide, one of the three detected candidates, significantly promoted new bone formation in vivo. Therefore, this double-screening method could identify candidates for osteogenesis-targeting compounds more reliably than conventional methods.
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3
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Kianfard Z, Cheung K, Rappaport D, Magalage SP, Sabatinos SA. Detecting Cell Cycle Stage and Progression in Fission Yeast, Schizosaccharomyces pombe. Methods Mol Biol 2022; 2579:235-246. [PMID: 36045211 DOI: 10.1007/978-1-0716-2736-5_18] [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] [Indexed: 06/15/2023]
Abstract
We have previously described methods to synchronize cultures of fission yeast, Schizosaccharomyces pombe. In this chapter, we provide methods to detect cell cycle stage in cells and populations of S. pombe. These protocols used fixed samples. First, we describe sample preparation for flow cytometry of bulk DNA content. This technique allows users to monitor progression of DNA replication and detect any perturbation during the synthesis (S) phase of the cell cycle. Second, we describe methods to stain nuclei and septa of fixed yeast cells, and monitor proportions of cell cycle stages within cultures. Together, these methods provide the ability to compare cell cycle progression or delay between cultures, making use of the powerful molecular genetics tool that is S. pombe.
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Affiliation(s)
- Zohreh Kianfard
- Molecular Science Program, Yeates School of Graduate Studies, Toronto Metropolitan University (formerly Ryerson University), Toronto, ON, Canada
| | - Kyle Cheung
- Molecular Science Program, Yeates School of Graduate Studies, Toronto Metropolitan University (formerly Ryerson University), Toronto, ON, Canada
| | - Daniel Rappaport
- Molecular Science Program, Yeates School of Graduate Studies, Toronto Metropolitan University (formerly Ryerson University), Toronto, ON, Canada
| | - Sirasie P Magalage
- Molecular Science Program, Yeates School of Graduate Studies, Toronto Metropolitan University (formerly Ryerson University), Toronto, ON, Canada
| | - Sarah A Sabatinos
- Molecular Science Program, Yeates School of Graduate Studies, Toronto Metropolitan University (formerly Ryerson University), Toronto, ON, Canada.
- Department of Chemistry and Biology, Toronto Metropolitan University (formerly Ryerson University), Toronto, ON, Canada.
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4
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Azar P, Mejía JE, Cenac C, Shaiykova A, Youness A, Laffont S, Essat A, Izopet J, Passaes C, Müller-Trutwin M, Delobel P, Meyer L, Guéry JC. TLR7 dosage polymorphism shapes interferogenesis and HIV-1 acute viremia in women. JCI Insight 2020; 5:136047. [PMID: 32554924 DOI: 10.1172/jci.insight.136047] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Accepted: 05/06/2020] [Indexed: 12/25/2022] Open
Abstract
Type I IFN (IFN-I) production by plasmacytoid DCs (pDCs) occurs during acute HIV-1 infection in response to TLR7 stimulation, but the role of pDC-derived IFN-I in controlling or promoting HIV-1 infection is ambiguous. We report here a sex-biased interferogenic phenotype for a frequent single-nucleotide polymorphism of human TLR7, rs179008, displaying an impact on key parameters of acute HIV-1 infection. We show allele rs179008 T to determine lower TLR7 protein abundance in cells from women, specifically - likely by diminishing TLR7 mRNA translation efficiency through codon usage. The hypomorphic TLR7 phenotype is mirrored by decreased TLR7-driven IFN-I production by female pDCs. Among women from the French ANRS PRIMO cohort of acute HIV-1 patients, carriage of allele rs179008 T associated with lower viremia, cell-associated HIV-1 DNA, and CXCL10 (IP-10) plasma concentrations. RNA viral load was decreased by 0.85 log10 (95% CI, -1.51 to -0.18) among T/T homozygotes, who also exhibited a lower frequency of acute symptoms. TLR7 emerges as an important control locus for acute HIV-1 viremia, and the clinical phenotype for allele rs179008 T, carried by 30%-50% of European women, supports a beneficial effect of toning down TLR7-driven IFN-I production by pDCs during acute HIV-1 infection.
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Affiliation(s)
- Pascal Azar
- Centre de Physiopathologie de Toulouse Purpan (CPTP), Université de Toulouse, UMR 1043 INSERM, CNRS, Toulouse, France
| | - José Enrique Mejía
- Centre de Physiopathologie de Toulouse Purpan (CPTP), Université de Toulouse, UMR 1043 INSERM, CNRS, Toulouse, France
| | - Claire Cenac
- Centre de Physiopathologie de Toulouse Purpan (CPTP), Université de Toulouse, UMR 1043 INSERM, CNRS, Toulouse, France
| | - Arnoo Shaiykova
- Centre de Recherche en Epidémiologie et Santé des Populations (CESP), Université Paris-Sud, Université Paris-Saclay, INSERM, Le Kremlin-Bicêtre, France
| | - Ali Youness
- Centre de Physiopathologie de Toulouse Purpan (CPTP), Université de Toulouse, UMR 1043 INSERM, CNRS, Toulouse, France
| | - Sophie Laffont
- Centre de Physiopathologie de Toulouse Purpan (CPTP), Université de Toulouse, UMR 1043 INSERM, CNRS, Toulouse, France
| | - Asma Essat
- Centre de Recherche en Epidémiologie et Santé des Populations (CESP), Université Paris-Sud, Université Paris-Saclay, INSERM, Le Kremlin-Bicêtre, France
| | - Jacques Izopet
- Centre de Physiopathologie de Toulouse Purpan (CPTP), Université de Toulouse, UMR 1043 INSERM, CNRS, Toulouse, France.,Laboratoire de Virologie, CHU Purpan, Toulouse, France
| | - Caroline Passaes
- Institut Pasteur, Unité HIV Inflammation et Persistance, Paris, France
| | | | - Pierre Delobel
- Centre de Physiopathologie de Toulouse Purpan (CPTP), Université de Toulouse, UMR 1043 INSERM, CNRS, Toulouse, France.,Service des Maladies Infectieuses et Tropicales, CHU Purpan, Toulouse, France
| | - Laurence Meyer
- Centre de Recherche en Epidémiologie et Santé des Populations (CESP), Université Paris-Sud, Université Paris-Saclay, INSERM, Le Kremlin-Bicêtre, France
| | - Jean-Charles Guéry
- Centre de Physiopathologie de Toulouse Purpan (CPTP), Université de Toulouse, UMR 1043 INSERM, CNRS, Toulouse, France
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5
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Naghizadeh S, Mansoori B, Mohammadi A, Sakhinia E, Baradaran B. Gene Silencing Strategies in Cancer Therapy: An Update for Drug Resistance. Curr Med Chem 2019; 26:6282-6303. [DOI: 10.2174/0929867325666180403141554] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2018] [Revised: 03/10/2018] [Accepted: 03/29/2018] [Indexed: 12/14/2022]
Abstract
RNAi, post-transcriptional gene silencing mechanism, could be considered as one of the
most important breakthroughs and rapidly growing fields in science. Researchers are trying to use this
discovery in the treatment of various diseases and cancer is one of them although there are multiple
treatment procedures for treatment-resistant cancers, eradication of resistance remain as an unsolvable
problem yet. The current review summarizes both transcriptional and post-transcriptional gene silencing
mechanisms, and highlights mechanisms leading to drug-resistance such as, drug efflux, drug inactivation,
drug target alteration, DNA damages repair, and the epithelial-mesenchymal transition, as
well as the role of tumor cell heterogeneity and tumor microenvironment, involving genes in these
processes. It ultimately points out the obstacles of RNAi application for in vivo treatment of diseases
and progressions that have been achieved in this field.
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Affiliation(s)
- Sanaz Naghizadeh
- Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Behzad Mansoori
- Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Ali Mohammadi
- Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Ebrahim Sakhinia
- Department of Medical Genetics, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Behzad Baradaran
- Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
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Butler MC, Sullivan JM. Ultrahigh Resolution Mouse Optical Coherence Tomography to Aid Intraocular Injection in Retinal Gene Therapy Research. J Vis Exp 2018. [PMID: 30451216 DOI: 10.3791/55894] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
HR-SD-OCT is utilized to monitor the progression of photoreceptor degeneration in live mouse models, assess the delivery of therapeutic agents into the subretinal space, and to evaluate toxicity and efficacy in vivo. HR-SD-OCT uses near infrared light (800-880 nm) and has optics specifically designed for the unique optics of the mouse eye with sub-2-micron axial resolution. Transgenic mouse models of outer retinal (photoreceptor) degeneration and controls were imaged to assess the disease progression. Pulled glass microneedles were used to deliver sub retinal injections of adeno-associated virus (AAV) or nanoparticles (NP) via a trans-scleral and trans-choroidal approach. Careful positioning of the needle into the subretinal space was required prior to a calibrated pressure injection, which delivers fluid into the sub retinal space. Real time subretinal surgery was conducted on our retinal imaging system (RIS). HR-SD-OCT demonstrated progressive uniform retinal degeneration due to expression of a toxic mutant human mutant rhodopsin (P347S) (RHOP347S) transgene in mice. HR-SD-OCT allows rigorous quantification of all the retinal layers. Outer nuclear layer (ONL) thickness and photoreceptor outer segment length (OSL) measurements correlate with photoreceptor vitality, degeneration, or rescue. The RIS delivery system allows real-time visualization of subretinal injections in neonatal (~P10-14) or adult mice, and HR-SD-OCT immediately determines success of delivery and maps areal extent. HR-SD-OCT is a powerful tool that can evaluate the success of subretinal surgery in mice, in addition to measuring vitality of photoreceptors in vivo. HR-SD-OCT can also be used to identify uniform animal cohorts to evaluate the extent of retinal degeneration, toxicity, and therapeutic rescue in preclinical gene therapy research studies.
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Affiliation(s)
- Mark C Butler
- Research Service, VA Western New York Healthcare System; Department of Ophthalmology, (Ross Eye Institute), Jacobs School of Medicine and Biomedical Sciences, University at Buffalo- SUNY
| | - Jack M Sullivan
- Research Service, VA Western New York Healthcare System; Department of Ophthalmology, (Ross Eye Institute), Jacobs School of Medicine and Biomedical Sciences, University at Buffalo- SUNY; Pharmacology/Toxicology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo- SUNY; Physiology/Biophysics, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo- SUNY; Neuroscience Program, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo- SUNY; The RNA Institute, University at Buffalo- SUNY; The SUNY Eye Institute;
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7
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Streamlined duplex live-dead microplate assay for cultured cells. Exp Eye Res 2017; 161:17-29. [PMID: 28572030 DOI: 10.1016/j.exer.2017.05.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Revised: 05/25/2017] [Accepted: 05/25/2017] [Indexed: 11/21/2022]
Abstract
A duplex fluorescence assay to assess the viability of cells cultured in multi-well plates is described, which can be carried out in the original culture plate using a plate reader, without exchanges of culture or assay medium, or transfer of cells or cell supernatant. The method uses freshly prepared reagents and does not rely on a proprietary, commercially supplied kit. Following experimental treatment, calcein acetoxymethyl ester (CaAM) is added to each well of cultured cells; after 30 min, the fluorescence intensity (emission λmax ∼ 530 nm) is measured. The signal is due to formation of calcein, which is produced from CaAM by action of esterase activity found in intact live cells. Since live cells may express plasma membrane multidrug transport proteins, especially of the ABC transporter family, the CaAM incubation is carried out in the presence of an inhibitor of this efflux process, thereby improving the dynamic range of the assay. Next, SYTOX® Orange (SO) is added to the culture wells, and, after a 30-min incubation, fluorescence intensity (emission λmax ∼ 590 nm) is measured again. SO is excluded from cells that have an intact plasma membrane, but penetrates dead/dying cells and can diffuse into the nucleus, where it binds to and forms a fluorescent complex with DNA. The CaAM already added to the wells causes no interference with the latter fluorescent signal. At the conclusion of the duplex assay, both live and dead cells remain in the culture wells and can be documented by digital imaging to demonstrate correlation of cellular morphology with the assay output. Two examples of the application of this method are provided, using cytotoxic compounds having different mechanisms of action.
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8
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Yau EH, Butler MC, Sullivan JM. A cellular high-throughput screening approach for therapeutic trans-cleaving ribozymes and RNAi against arbitrary mRNA disease targets. Exp Eye Res 2016; 151:236-55. [PMID: 27233447 DOI: 10.1016/j.exer.2016.05.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2016] [Revised: 04/25/2016] [Accepted: 05/22/2016] [Indexed: 12/11/2022]
Abstract
Major bottlenecks in development of therapeutic post transcriptional gene silencing (PTGS) agents (e.g. ribozymes, RNA interference, antisense) include the challenge of mapping rare accessible regions of the mRNA target that are open for annealing and cleavage, testing and optimization of agents in human cells to identify lead agents, testing for cellular toxicity, and preclinical evaluation in appropriate animal models of disease. Methods for rapid and reliable cellular testing of PTGS agents are needed to identify potent lead candidates for optimization. Our goal was to develop a means of rapid assessment of many RNA agents to identify a lead candidate for a given mRNA associated with a disease state. We developed a rapid human cell-based screening platform to test efficacy of hammerhead ribozyme (hhRz) or RNA interference (RNAi) constructs, using a model retinal degeneration target, human rod opsin (RHO) mRNA. The focus is on RNA Drug Discovery for diverse retinal degeneration targets. To validate the approach, candidate hhRzs were tested against NUH↓ cleavage sites (N = G,C,A,U; H = C,A,U) within the target mRNA of secreted alkaline phosphatase (SEAP), a model gene expression reporter, based upon in silico predictions of mRNA accessibility. HhRzs were embedded in a larger stable adenoviral VAI RNA scaffold for high cellular expression, cytoplasmic trafficking, and stability. Most hhRz expression plasmids exerted statistically significant knockdown of extracellular SEAP enzyme activity when readily assayed by a fluorescence enzyme assay intended for high throughput screening (HTS). Kinetics of PTGS knockdown of cellular targets is measureable in live cells with the SEAP reporter. The validated SEAP HTS platform was transposed to identify lead PTGS agents against a model hereditary retinal degeneration target, RHO mRNA. Two approaches were used to physically fuse the model retinal gene target mRNA to the SEAP reporter mRNA. The most expedient way to evaluate a large set of potential VAI-hhRz expression plasmids against diverse NUH↓ cleavage sites uses cultured human HEK293S cells stably expressing a dicistronic Target-IRES-SEAP target fusion mRNA. Broad utility of this rational RNA drug discovery approach is feasible for any ophthalmological disease-relevant mRNA targets and any disease mRNA targets in general. The approach will permit rank ordering of PTGS agents based on potency to identify a lead therapeutic compound for further optimization.
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Affiliation(s)
- Edwin H Yau
- Department of Pharmacology/Toxicology, University at Buffalo- SUNY, Buffalo, NY 14209, USA; Department of Ophthalmology (Ira G. Ross Eye Institute), University at Buffalo- SUNY, Buffalo, NY 14209, USA
| | - Mark C Butler
- Department of Ophthalmology (Ira G. Ross Eye Institute), University at Buffalo- SUNY, Buffalo, NY 14209, USA
| | - Jack M Sullivan
- Research Service, VA Western New York Healthcare System, Buffalo, NY 14215, USA; Department of Ophthalmology (Ira G. Ross Eye Institute), University at Buffalo- SUNY, Buffalo, NY 14209, USA; Department of Pharmacology/Toxicology, University at Buffalo- SUNY, Buffalo, NY 14209, USA; Department of Physiology/Biophysics, University at Buffalo- SUNY, Buffalo, NY 14209, USA; Neuroscience Program, University at Buffalo- SUNY, Buffalo, NY 14209, USA; SUNY Eye Institute, University at Albany- SUNY, USA; RNA Institute, University at Albany- SUNY, USA.
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9
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Recent advances in the rational design of silica-based nanoparticles for gene therapy. Ther Deliv 2012. [DOI: 10.4155/tde.12.98] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Gene therapy has attracted much attention in modern society and provides a promising approach for treating genetic disorders, diseases and cancers. Safe and effective vectors are vital tools to deliver genetic molecules to cells. This review summarizes recent advances in the rational design of silica-based nanoparticles and their applications in gene therapy. An overview of different types of genetic agents available for gene therapy is provided. The engineering of various silica nanoparticles is described, which can be used as versatile complexation tools for genetic agents and advanced gene therapy. Several challenges are raised and future research directions in the area of gene therapy using silica-based nanoparticles are proposed.
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Sullivan JM, Yau EH, Kolniak TA, Sheflin LG, Taggart RT, Abdelmaksoud HE. Variables and strategies in development of therapeutic post-transcriptional gene silencing agents. J Ophthalmol 2011; 2011:531380. [PMID: 21785698 PMCID: PMC3138052 DOI: 10.1155/2011/531380] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2010] [Revised: 02/17/2011] [Accepted: 02/28/2011] [Indexed: 11/24/2022] Open
Abstract
Post-transcriptional gene silencing (PTGS) agents such as ribozymes, RNAi and antisense have substantial potential for gene therapy of human retinal degenerations. These technologies are used to knockdown a specific target RNA and its cognate protein. The disease target mRNA may be a mutant mRNA causing an autosomal dominant retinal degeneration or a normal mRNA that is overexpressed in certain diseases. All PTGS technologies depend upon the initial critical annealing event of the PTGS ligand to the target RNA. This event requires that the PTGS agent is in a conformational state able to support hybridization and that the target have a large and accessible single-stranded platform to allow rapid annealing, although such platforms are rare. We address the biocomplexity that currently limits PTGS therapeutic development with particular emphasis on biophysical variables that influence cellular performance. We address the different strategies that can be used for development of PTGS agents intended for therapeutic translation. These issues apply generally to the development of PTGS agents for retinal, ocular, or systemic diseases. This review should assist the interested reader to rapidly appreciate critical variables in PTGS development and facilitate initial design and testing of such agents against new targets of clinical interest.
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Affiliation(s)
- Jack M. Sullivan
- Department of Ophthalmology, University at Buffalo SUNY, Buffalo, NY 14214, USA
- Department of Pharmacology and Toxicology, University at Buffalo SUNY, Buffalo, NY 14214, USA
- Department of Physiology and Biophysics, University at Buffalo SUNY, Buffalo, NY 14214, USA
- Neuroscience Program, University at Buffalo SUNY, Buffalo, NY 14214, USA
- Ross Eye Institute, University at Buffalo SUNY, Buffalo, NY 14209, USA
- Veterans Administration Western New York Healthcare System, Medical Research, Buffalo, NY 14215, USA
| | - Edwin H. Yau
- Department of Ophthalmology, University at Buffalo SUNY, Buffalo, NY 14214, USA
- Department of Pharmacology and Toxicology, University at Buffalo SUNY, Buffalo, NY 14214, USA
| | - Tiffany A. Kolniak
- Department of Ophthalmology, University at Buffalo SUNY, Buffalo, NY 14214, USA
- Neuroscience Program, University at Buffalo SUNY, Buffalo, NY 14214, USA
| | - Lowell G. Sheflin
- Department of Ophthalmology, University at Buffalo SUNY, Buffalo, NY 14214, USA
- Veterans Administration Western New York Healthcare System, Medical Research, Buffalo, NY 14215, USA
| | - R. Thomas Taggart
- Department of Ophthalmology, University at Buffalo SUNY, Buffalo, NY 14214, USA
| | - Heba E. Abdelmaksoud
- Department of Neuroscience and Physiology, Upstate Medical University, Syracuse, NY 13215, USA
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