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Oliynyk RT, Church GM. Efficient modification and preparation of circular DNA for expression in cell culture. Commun Biol 2022; 5:1393. [PMID: 36543890 PMCID: PMC9772414 DOI: 10.1038/s42003-022-04363-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 12/09/2022] [Indexed: 12/24/2022] Open
Abstract
DNA plasmids are an essential tool for delivery and expression of RNAs and proteins in cell culture experiments. The preparation of plasmids typically involves a laborious process of bacterial cloning, validation, and purification. While the expression plasmids can be designed and ordered from the contract manufacturers, the cost may be prohibitive when a large number of plasmids is required. We have developed an efficient fully synthetic method and protocol that enables the production of circularized DNA containing expression elements ready for transfection in as little as 3 hours, thereby eliminating the bacterial cloning steps. The protocol describes how to take a linear double-stranded DNA fragment and efficiently circularize and purify this DNA fragment with minimal hands-on time. As proof of the principle, we applied Circular Vector expressing engineered prime editing guide RNA (epegRNA) in cell culture, and demonstrated matching and even exceeding performance of this method as compared to guides expressed by plasmids. The method's speed of preparation, low cost, and ease of use will make it a useful tool in applications requiring the expression of short RNAs and proteins.
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Affiliation(s)
- Roman Teo Oliynyk
- Department of Genetics, Harvard Medical School, Boston, MA, USA.
- Department of Computer Science, University of Auckland, Auckland, New Zealand.
| | - George M Church
- Department of Genetics, Harvard Medical School, Boston, MA, USA
- Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, MA, USA
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Pang KM, Castanotto D, Li H, Scherer L, Rossi JJ. Incorporation of aptamers in the terminal loop of shRNAs yields an effective and novel combinatorial targeting strategy. Nucleic Acids Res 2019; 46:e6. [PMID: 29077949 PMCID: PMC5758892 DOI: 10.1093/nar/gkx980] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 10/23/2017] [Indexed: 01/12/2023] Open
Abstract
Gene therapy by engineering patient's own blood cells to confer HIV resistance can potentially lead to a functional cure for AIDS. Toward this goal, we have previously developed an anti-HIV lentivirus vector that deploys a combination of shRNA, ribozyme and RNA decoy. To further improve this therapeutic vector against viral escape, we sought an additional reagent to target HIV integrase. Here, we report the development of a new strategy for selection and expression of aptamer for gene therapy. We developed a SELEX protocol (multi-tag SELEX) for selecting RNA aptamers against proteins with low solubility or stability, such as integrase. More importantly, we expressed these aptamers in vivo by incorporating them in the terminal loop of shRNAs. This novel strategy allowed efficient expression of the shRNA–aptamer fusions that targeted RNAs and proteins simultaneously. Expressed shRNA–aptamer fusions targeting HIV integrase or reverse transcriptase inhibited HIV replication in cell cultures. Viral inhibition was further enhanced by combining an anti-integrase aptamer with an anti-HIV Tat-Rev shRNA. This construct exhibited efficacy comparable to that of integrase inhibitor Raltegravir. Our strategy for the selection and expression of RNA aptamers can potentially extend to other gene therapy applications.
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Affiliation(s)
- Ka Ming Pang
- Department of Molecular and Cellular Biology, Beckman Research Institute of City of Hope, Duarte, CA 91010, USA.,Department of Medical Oncology & Therapeutics Research, City of Hope National Cancer Center, Duarte, CA 91010, USA
| | - Daniela Castanotto
- Department of Medical Oncology & Therapeutics Research, City of Hope National Cancer Center, Duarte, CA 91010, USA
| | - Haitang Li
- Department of Molecular and Cellular Biology, Beckman Research Institute of City of Hope, Duarte, CA 91010, USA
| | - Lisa Scherer
- Department of Molecular and Cellular Biology, Beckman Research Institute of City of Hope, Duarte, CA 91010, USA
| | - John J Rossi
- Department of Molecular and Cellular Biology, Beckman Research Institute of City of Hope, Duarte, CA 91010, USA.,Irell and Manella Graduate School of Biological Sciences, Beckman Research Institute of City of Hope, Duarte, CA 91010, USA
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Green VA, Weinberg MS. Small RNA-induced transcriptional gene regulation in mammals mechanisms, therapeutic applications, and scope within the genome. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2011; 102:11-46. [PMID: 21846568 DOI: 10.1016/b978-0-12-415795-8.00005-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Argonaute-bound small RNAs, derived from RNA interference and related pathways, are well-known effectors of posttranscriptional gene silencing (PTGS). Yet, these complexes also play an important role in affecting gene expression at the transcriptional level, either by transcriptional gene silencing (TGS) or activation (TGA). Our current understanding of how small RNAs are able to both activate and suppress transcription is unclear. In this review, we briefly outline the biogenesis of small RNAs and explore the mechanisms behind the various phenomena attributed to AGO-bound small RNA-mediated transcriptional regulation. The therapeutic potential of TGS and TGA is examined, emphasizing the distinct advantages over PTGS approaches with examples of application to cancer and diseases associated with viruses, aberrant splicing, and dysregulated heterochromatin. Finally, the influence of promoter architecture on gene susceptibility to transcriptional regulation is discussed in the light of how this impacts the scope of small RNA-induced transcriptional regulation within the genome.
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Affiliation(s)
- Victoria A Green
- Department of Molecular Medicine and Haematology, University of the Witwatersrand, Johannesburg, South Africa
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Şalva E, Kabasakal L, Eren F, Çakalağaoğlu F, Özkan N, Akbuğa J. Chitosan/Short Hairpin RNA Complexes for Vascular Endothelial Growth Factor Suppression Invasive Breast Carcinoma. Oligonucleotides 2010; 20:183-90. [DOI: 10.1089/oli.2010.0241] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Emine Şalva
- Department of Pharmaceutical Biotechnology, Faculty of Pharmacy, Marmara University, Istanbul, Turkey
- Pathology Laboratory, Vocational Health School, Marmara University, Istanbul, Turkey
| | - Levent Kabasakal
- Department of Pharmacology, Faculty of Pharmacy, Marmara University, Istanbul, Turkey
| | - Fatih Eren
- Institute of Gastroenterology, Marmara University, Istanbul, Turkey
| | - Fulya Çakalağaoğlu
- Pathology Department, Izmir Ataturk Education and Research Hospital, Istanbul, Turkey
| | - Naziye Özkan
- Pathology Laboratory, Vocational Health School, Marmara University, Istanbul, Turkey
| | - Jülide Akbuğa
- Department of Pharmaceutical Biotechnology, Faculty of Pharmacy, Marmara University, Istanbul, Turkey
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Abstract
The ability to interfere with gene expression is of crucial importance to unravel the function of genes and is also a promising therapeutic strategy. Here we discuss methodologies for inhibition of target RNAs based on the cleavage activity of the essential enzyme, Ribonuclease P (RNase P). RNase P-mediated cleavage of target RNAs can be directed by external guide sequences (EGSs) or by the use of the catalytic M1 RNA from E. coli linked to a guide sequence (M1GSs). These are not only basic tools for functional genetic studies in prokaryotic and eukaryotic cells but also promising antibacterial, anticancer and antiviral agents.
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Affiliation(s)
- Eirik Wasmuth Lundblad
- Reference Centre for Detection of Antimicrobial Resistance, Department of Microbiology and Infection Control, University Hospital of North Norway, 9038 Tromsø, Norway.
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Yang CJ, Liu YK, Liu CL, Shen CN, Kuo ML, Su CC, Tseng CP, Yen TC, Shen CR. Inhibition of acidic mammalian chitinase by RNA interference suppresses ovalbumin-sensitized allergic asthma. Hum Gene Ther 2010; 20:1597-606. [PMID: 19548841 DOI: 10.1089/hum.2008.092] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Asthma, a chronic helper T cell type 2-mediated inflammatory disease, is characterized by airway hyperresponsiveness and inflammation. Growing evidence suggests that increased expression of acidic mammalian chitinase (AMCase) may play a role in the pathogenesis of asthma. In the present study, we sought to develop an RNA interference approach to suppress allergic asthma in mice through silencing of AMCase expression. Mice sensitized with ovalbumin (OVA) were intratracheally administered a recombinant adeno-associated virus expressing short hairpin RNA (rAAV-shRNA) against AMCase. In OVA-sensitized mice, the development of allergic symptoms was significantly associated with elevated AMCase expression. After administration of rAAV-shRNA, there was a significant reduction of AMCase expression in the lung and in bronchoalveolar lavage fluid (BALF) cells of sensitized mice. Sensitized mice receiving rAAV-shRNA showed a significant improvement in allergic symptoms, including airway hyperresponsiveness (AHR), eosinophil infiltration, eotaxin, interleukin-13 secretion in BALF, and serum OVA-specific IgE level. Our data suggest the hyperexpression of AMCase in asthma can be suppressed by rAAV-mediated shRNA. Silencing AMCase expression by shRNA may be a promising therapeutic strategy in asthma.
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Affiliation(s)
- Ching-Jen Yang
- Department of Chemical and Materials Engineering, Chang Gung University, Taoyuan 333, Taiwan
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Shin D, Lee H, Kim SI, Yoon Y, Kim M. Optimization of linear double-stranded RNA for the production of multiple siRNAs targeting hepatitis C virus. RNA (NEW YORK, N.Y.) 2009; 15:898-910. [PMID: 19324960 PMCID: PMC2673075 DOI: 10.1261/rna.1268209] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2008] [Accepted: 02/13/2009] [Indexed: 05/27/2023]
Abstract
RNA interference (RNAi)-based gene silencing possesses great therapeutic potential for inhibiting replication of human viruses such as hepatitis C virus (HCV). However, one of the putative limitations for its use as a therapy is the rapid emergence of escape variants. These contain deletions or mutations within the viral genome sequences complementary to the small interfering RNAs (siRNAs) or short hairpin RNAs (shRNAs) being used for treatment. As a potential solution to this problem, we constructed an expression system for duplex RNAs harboring two siRNA units using convergent H1 and U6 Pol III promoters. Here, the length and orientation of the transcript, tandem siRNA (tsiRNA), were optimized to be processed by the intracellular ribonuclease Dicer into functional siRNAs targeting different sequences. Assessment in transfected cells indicates that the length of the tsiRNA duplex (40-42 base pairs) is more critical for both siRNA-producing capacity and gene silencing activity than the orientation of each siRNA unit. In Huh7 cells replicating full-length HCV RNA, expression of length-optimized tsiRNA inhibited viral protein levels as efficiently as a single 21-nucleotide siRNA-expression construct, without affecting miRNA maturation or induction of an interferon response. We verified that the anti-viral activity of tsiRNA was achieved by precise cleavage of two target sites. A distinct advantage of this strategy is that each side of the optimized linear duplex RNA could enter into the Dicer-mediated processing machinery, thus likely providing more equal and efficient production of multiple siRNAs required for reducing the chance of viral escape.
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Affiliation(s)
- Duckhyang Shin
- Virus Research Laboratory, Mogam Biotechnology Research Institute, Yongin-si, Gyeonggi-do, 449-913, South Korea
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