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Kines KJ, Sokolowski M, DeFreece C, Shareef A, deHaro DL, Belancio VP. Large Deletions, Cleavage of the Telomeric Repeat Sequence, and Reverse Transcriptase-Mediated DNA Damage Response Associated with Long Interspersed Element-1 ORF2p Enzymatic Activities. Genes (Basel) 2024; 15:143. [PMID: 38397133 PMCID: PMC10887698 DOI: 10.3390/genes15020143] [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: 12/22/2023] [Revised: 01/17/2024] [Accepted: 01/18/2024] [Indexed: 02/25/2024] Open
Abstract
L1 elements can cause DNA damage and genomic variation via retrotransposition and the generation of endonuclease-dependent DNA breaks. These processes require L1 ORF2p protein that contains an endonuclease domain, which cuts genomic DNA, and a reverse transcriptase domain, which synthesizes cDNA. The complete impact of L1 enzymatic activities on genome stability and cellular function remains understudied, and the spectrum of L1-induced mutations, other than L1 insertions, is mostly unknown. Using an inducible system, we demonstrate that an ORF2p containing functional reverse transcriptase is sufficient to elicit DNA damage response even in the absence of the functional endonuclease. Using a TK/Neo reporter system that captures misrepaired DNA breaks, we demonstrate that L1 expression results in large genomic deletions that lack any signatures of L1 involvement. Using an in vitro cleavage assay, we demonstrate that L1 endonuclease efficiently cuts telomeric repeat sequences. These findings support that L1 could be an unrecognized source of disease-promoting genomic deletions, telomere dysfunction, and an underappreciated source of chronic RT-mediated DNA damage response in mammalian cells. Our findings expand the spectrum of biological processes that can be triggered by functional and nonfunctional L1s, which have impactful evolutionary- and health-relevant consequences.
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Affiliation(s)
- Kristine J. Kines
- Department of Structural and Cellular Biology, Tulane School of Medicine, Tulane Cancer Center, New Orleans, LA 70112, USA
| | - Mark Sokolowski
- Department of Structural and Cellular Biology, Tulane School of Medicine, Tulane Cancer Center, New Orleans, LA 70112, USA
| | - Cecily DeFreece
- Department of Biology, Xavier University of Louisiana, New Orleans, LA 70125, USA
| | - Afzaal Shareef
- Department of Structural and Cellular Biology, Tulane School of Medicine, Tulane Cancer Center, New Orleans, LA 70112, USA
| | - Dawn L. deHaro
- Department of Structural and Cellular Biology, Tulane School of Medicine, Tulane Cancer Center, New Orleans, LA 70112, USA
| | - Victoria P. Belancio
- Department of Structural and Cellular Biology, Tulane School of Medicine, Tulane Cancer Center, New Orleans, LA 70112, USA
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2
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Ren CY, Zhao HP. Synthetic Nuclease-Producing Microbiome Achieves Efficient Removal of Extracellular Antibiotic Resistance Genes from Wastewater Effluent. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:21224-21234. [PMID: 38059467 DOI: 10.1021/acs.est.3c07974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/08/2023]
Abstract
Antibiotic resistance gene (ARG) transmission poses significant threats to human health. The effluent of wastewater treatment plants is demonstrated as a hotspot source of ARGs released into the environment. In this study, a synthetic microbiome containing nuclease-producing Deinococcus radiodurans was constructed to remove extracellular ARGs. Results of quantitative polymerase chain reaction (qPCR) showed significant reduction in plasmid RP4-associated ARGs (by more than 3 orders of magnitude) and reduction of indigenous ARG sul1 and mobile genetic element (MGE) intl1 (by more than 1 order of magnitude) in the synthetic microbiome compared to the control without D. radiodurans. Metagenomic analysis revealed a decrease in ARG and MGE diversity in extracellular DNA (eDNA) of the treated group. Notably, whereas eight antibiotic-resistant plasmids with mobility risk were detected in the control, only one was detected in the synthetic microbiome. The abundance of the nuclease encoding gene exeM, quantified by qPCR, indicated its enrichment in the synthetic microbiome, which ensures stable eDNA degradation even when D. radiodurans decreased. Moreover, intracellular ARGs and MGEs and pathogenic ARG hosts in the river receiving treated effluent were lower than those in the river receiving untreated effluent. Overall, this study presents a new approach for removing extracellular ARGs and further reducing the risk of ARG transmission in receiving rivers.
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Affiliation(s)
- Chong-Yang Ren
- MOE Key Lab of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Science, Zhejiang University, Hangzhou 310058, China
| | - He-Ping Zhao
- MOE Key Lab of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Science, Zhejiang University, Hangzhou 310058, China
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3
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Samanta A, Lufkin T, Kraus P. Intervertebral disc degeneration-Current therapeutic options and challenges. Front Public Health 2023; 11:1156749. [PMID: 37483952 PMCID: PMC10359191 DOI: 10.3389/fpubh.2023.1156749] [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: 02/01/2023] [Accepted: 06/12/2023] [Indexed: 07/25/2023] Open
Abstract
Degeneration of the intervertebral disc (IVD) is a normal part of aging. Due to the spine's declining function and the development of pain, it may affect one's physical health, mental health, and socioeconomic status. Most of the intervertebral disc degeneration (IVDD) therapies today focus on the symptoms of low back pain rather than the underlying etiology or mechanical function of the disc. The deteriorated disc is typically not restored by conservative or surgical therapies that largely focus on correcting symptoms and structural abnormalities. To enhance the clinical outcome and the quality of life of a patient, several therapeutic modalities have been created. In this review, we discuss genetic and environmental causes of IVDD and describe promising modern endogenous and exogenous therapeutic approaches including their applicability and relevance to the degeneration process.
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Chung CH, Murphy CM, Wingate VP, Pavlicek JW, Nakashima R, Wei W, McCarty D, Rabinowitz J, Barton E. Production of rAAV by plasmid transfection induces antiviral and inflammatory responses in suspension HEK293 cells. Mol Ther Methods Clin Dev 2023; 28:272-283. [PMID: 36819978 PMCID: PMC9937832 DOI: 10.1016/j.omtm.2023.01.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Accepted: 01/13/2023] [Indexed: 01/18/2023]
Abstract
Recombinant adeno-associated virus (rAAV) is a clinically proven viral vector for delivery of therapeutic genes to treat rare diseases. Improving rAAV manufacturing productivity and vector quality is necessary to meet clinical and commercial demand. These goals will require an improved understanding of the cellular response to rAAV production, which is poorly defined. We interrogated the kinetic transcriptional response of HEK293 cells to rAAV production following transient plasmid transfection, under manufacturing-relevant conditions, using RNA-seq. Time-series analyses identified a robust cellular response to transfection and rAAV production, with 1,850 transcripts differentially expressed. Gene Ontology analysis determined upregulated pathways, including inflammatory and antiviral responses, with several interferon-stimulated cytokines and chemokines being upregulated at the protein level. Literature-based pathway prediction implicated multiple pathogen pattern sensors and signal transducers in up-regulation of inflammatory and antiviral responses in response to transfection and rAAV replication. Systematic analysis of the cellular transcriptional response to rAAV production indicates that host cells actively sense vector manufacture as an infectious insult. This dataset may therefore illuminate genes and pathways that influence rAAV production, thereby enabling the rational design of next-generation manufacturing platforms to support safe, effective, and affordable AAV-based gene therapies.
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Affiliation(s)
- Cheng-Han Chung
- Pfizer Inc., Worldwide Research, Development and Medical, Bioprocess Research and Development, Morrisville, NC 27560, USA
| | - Christopher M. Murphy
- Pfizer Inc., Worldwide Research, Development and Medical, Bioprocess Research and Development, Morrisville, NC 27560, USA
| | - Vincent P. Wingate
- Pfizer Inc., Worldwide Research, Development and Medical, Bioprocess Research and Development, Morrisville, NC 27560, USA
| | - Jeffrey W. Pavlicek
- Pfizer Inc., Worldwide Research, Development and Medical, Bioprocess Research and Development, Morrisville, NC 27560, USA
| | - Reiko Nakashima
- Pfizer Inc., Worldwide Research, Development and Medical, Simulation and Modeling Sciences, Cambridge, MA 02139, USA
| | - Wei Wei
- Pfizer Inc., Worldwide Research, Development and Medical, Bioprocess Research and Development, Morrisville, NC 27560, USA
| | - Douglas McCarty
- Pfizer Inc., Worldwide Research, Development and Medical, Rare Disease Research Unit, Morrisville, NC 27560, USA
| | - Joseph Rabinowitz
- Pfizer Inc., Worldwide Research, Development and Medical, Rare Disease Research Unit, Morrisville, NC 27560, USA
| | - Erik Barton
- Pfizer Inc., Worldwide Research, Development and Medical, Bioprocess Research and Development, Morrisville, NC 27560, USA,Corresponding author: Erik Barton, Pfizer Inc., Worldwide Research, Development and Medical, Bioprocess Research and Development, Morrisville, NC 27560, USA.
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5
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Ren CY, Xu QJ, Mathieu J, Alvarez PJJ, Zhu L, Zhao HP. A Carotenoid- and Nuclease-Producing Bacterium Can Mitigate Enterococcus faecalis Transformation by Antibiotic Resistance Genes. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:15167-15178. [PMID: 35862635 DOI: 10.1021/acs.est.2c03919] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Dissemination of antibiotic resistance genes (ARGs) through natural transformation is facilitated by factors that stabilize extracellular DNA (eDNA) and that induce reactive oxygen species (ROS) that permeabilize receptor cells and upregulate transformation competence genes. In this study, we demonstrate that Deinococcus radiodurans can mitigate this ARG dissemination pathway by removing both eDNA and ROS that make recipient cells more vulnerable to transformation. We used plasmid RP4 as source of extracellular ARGs (tetA, aphA, and blaTEM-2) and the opportunistic pathogen Enterococcus faecalis as receptor. The presence of D. radiodurans significantly reduced the transformation frequency from 2.5 ± 0.7 × 10-6 to 7.4 ± 1.4 × 10-7 (p < 0.05). Based on quantification of intracellular ROS accumulation and superoxide dismutase (SOD) activity, and quantitative polymerase chain reaction (qPCR) and transcriptomic analyses, we propose two mechanisms by which D. radiodurans mitigates E. faecalis transformation by ARGs: (a) residual antibiotics induce D. radiodurans to synthesize liposoluble carotenoids that scavenge ROS and thus mitigate the susceptibility of E. faecalis for eDNA uptake, and (b) eDNA induces D. radiodurans to synthesize extracellular nucleases that degrade eARGs. This mechanistic insight informs biological strategies (including bioaugmentation) to curtail the spread of ARGs through transformation.
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Affiliation(s)
- Chong-Yang Ren
- MOE Key Lab of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Science, Zhejiang University, Hangzhou, China, 310058
| | - Qiu-Jin Xu
- MOE Key Lab of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Science, Zhejiang University, Hangzhou, China, 310058
| | - Jacques Mathieu
- Department of Civil and Environmental Engineering, Rice University, Houston, Texas 77005, United States
| | - Pedro J J Alvarez
- Department of Civil and Environmental Engineering, Rice University, Houston, Texas 77005, United States
| | - Lizhong Zhu
- MOE Key Lab of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Science, Zhejiang University, Hangzhou, China, 310058
| | - He-Ping Zhao
- MOE Key Lab of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Science, Zhejiang University, Hangzhou, China, 310058
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Frasson I, Pirota V, Richter SN, Doria F. Multimeric G-quadruplexes: A review on their biological roles and targeting. Int J Biol Macromol 2022; 204:89-102. [PMID: 35124022 DOI: 10.1016/j.ijbiomac.2022.01.197] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 01/20/2022] [Accepted: 01/31/2022] [Indexed: 12/12/2022]
Abstract
In human cells, nucleic acids adopt several non-canonical structures that regulate key cellular processes. Among them, G-quadruplexes (G4s) are stable structures that form in guanine-rich regions in vitro and in cells. G4 folded/unfolded state shapes numerous cellular processes, including genome replication, transcription, and translation. Moreover, G4 folding is involved in genomic instability. G4s have been described to multimerize, forming high-order structures in both DNA and/or RNA strands. Multimeric G4s can be formed by adjacent intramolecular G4s joined by stacking interactions or connected by short loops. Multimeric G4s can also originate from the assembly of guanines embedded on independent DNA or RNA strands. Notably, crucial regions of the human genome, such as the 3'-terminal overhang of the telomeric DNA as well as the open reading frame of genes involved in the preservation of neuron viability in the human central and peripheral nervous system are prone to form multimeric G4s. The biological importance of such structures has been recently described, with multimeric G4s playing potentially protective or deleterious effects in the pathogenic cascade of various diseases. Here, we portray the multifaceted scenario of multimeric G4s, in terms of structural properties, biological roles, and targeting strategies.
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Affiliation(s)
- Ilaria Frasson
- Department of Molecular Medicine, University of Padova, via A. Gabelli 63, 35121 Padova, Italy
| | - Valentina Pirota
- Department of Chemistry, University of Pavia, v. le Taramelli 10, 27100 Pavia, Italy; G4-INTERACT, USERN, v. le Taramelli 10, 27100 Pavia, Italy
| | - Sara N Richter
- Department of Molecular Medicine, University of Padova, via A. Gabelli 63, 35121 Padova, Italy.
| | - Filippo Doria
- Department of Chemistry, University of Pavia, v. le Taramelli 10, 27100 Pavia, Italy.
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7
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Benjamin R, Banerjee A, Wu X, Geurink C, Buczek L, Eames D, Trimidal SG, Pluth JM, Schiller MR. XRCC4 and MRE11 Roles and Transcriptional Response to Repair of TALEN-Induced Double-Strand DNA Breaks. Int J Mol Sci 2022; 23:ijms23020593. [PMID: 35054780 PMCID: PMC8776116 DOI: 10.3390/ijms23020593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 12/30/2021] [Accepted: 01/03/2022] [Indexed: 02/04/2023] Open
Abstract
Double-strand breaks (DSB) are one of the most lethal forms of DNA damage that, if left unrepaired, can lead to genomic instability, cellular transformation, and cell death. In this work, we examined how repair of transcription activator-like effector nuclease (TALEN)-induced DNA damage was altered when knocking out, or inhibiting a function of, two DNA repair proteins, XRCC4 and MRE11, respectively. We developed a fluorescent reporter assay that uses TALENs to introduce DSB and detected repair by the presence of GFP fluorescence. We observed repair of TALEN-induced breaks in the XRCC4 knockout cells treated with mirin (a pharmacological inhibitor of MRE11 exonuclease activity), albeit with ~40% reduced efficiency compared to normal cells. Editing in the absence of XRCC4 or MRE11 exonuclease was robust, with little difference between the indel profiles amongst any of the groups. Reviewing the transcriptional profiles of the mirin-treated XRCC4 knockout cells showed 307 uniquely differentially expressed genes, a number far greater than for either of the other cell lines (the HeLa XRCC4 knockout sample had 83 genes, and the mirin-treated HeLa cells had 30 genes uniquely differentially expressed). Pathways unique to the XRCC4 knockout+mirin group included differential expression of p53 downstream pathways, and metabolic pathways indicating cell adaptation for energy regulation and stress response. In conclusion, our study showed that TALEN-induced DSBs are repaired, even when a key DSB repair protein or protein function is not operational, without a change in indel profiles. However, transcriptional profiles indicate the induction of unique cellular responses dependent upon the DNA repair protein(s) hampered.
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Affiliation(s)
- Ronald Benjamin
- Nevada Institute of Personalized Medicine, University of Nevada Las Vegas, Las Vegas, NV 89154, USA; (A.B.); (X.W.); (C.G.); (L.B.); (D.E.); (S.G.T.)
- School of Life Science, University of Nevada Las Vegas, Las Vegas, NV 89154, USA
- Correspondence: (R.B.); (M.R.S.); Tel.: +1-(702)927-9325 (R.B.); +1-(702)895-5546 (M.R.S.)
| | - Atoshi Banerjee
- Nevada Institute of Personalized Medicine, University of Nevada Las Vegas, Las Vegas, NV 89154, USA; (A.B.); (X.W.); (C.G.); (L.B.); (D.E.); (S.G.T.)
- School of Life Science, University of Nevada Las Vegas, Las Vegas, NV 89154, USA
| | - Xiaogang Wu
- Nevada Institute of Personalized Medicine, University of Nevada Las Vegas, Las Vegas, NV 89154, USA; (A.B.); (X.W.); (C.G.); (L.B.); (D.E.); (S.G.T.)
| | - Corey Geurink
- Nevada Institute of Personalized Medicine, University of Nevada Las Vegas, Las Vegas, NV 89154, USA; (A.B.); (X.W.); (C.G.); (L.B.); (D.E.); (S.G.T.)
- School of Life Science, University of Nevada Las Vegas, Las Vegas, NV 89154, USA
| | - Lindsay Buczek
- Nevada Institute of Personalized Medicine, University of Nevada Las Vegas, Las Vegas, NV 89154, USA; (A.B.); (X.W.); (C.G.); (L.B.); (D.E.); (S.G.T.)
- School of Life Science, University of Nevada Las Vegas, Las Vegas, NV 89154, USA
| | - Danielle Eames
- Nevada Institute of Personalized Medicine, University of Nevada Las Vegas, Las Vegas, NV 89154, USA; (A.B.); (X.W.); (C.G.); (L.B.); (D.E.); (S.G.T.)
- School of Life Science, University of Nevada Las Vegas, Las Vegas, NV 89154, USA
| | - Sara G. Trimidal
- Nevada Institute of Personalized Medicine, University of Nevada Las Vegas, Las Vegas, NV 89154, USA; (A.B.); (X.W.); (C.G.); (L.B.); (D.E.); (S.G.T.)
- School of Life Science, University of Nevada Las Vegas, Las Vegas, NV 89154, USA
| | - Janice M. Pluth
- Health Physics and Diagnostic Sciences, University of Nevada Las Vegas, Las Vegas, NV 89154, USA;
| | - Martin R. Schiller
- Nevada Institute of Personalized Medicine, University of Nevada Las Vegas, Las Vegas, NV 89154, USA; (A.B.); (X.W.); (C.G.); (L.B.); (D.E.); (S.G.T.)
- School of Life Science, University of Nevada Las Vegas, Las Vegas, NV 89154, USA
- Correspondence: (R.B.); (M.R.S.); Tel.: +1-(702)927-9325 (R.B.); +1-(702)895-5546 (M.R.S.)
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8
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Fus-Kujawa A, Prus P, Bajdak-Rusinek K, Teper P, Gawron K, Kowalczuk A, Sieron AL. An Overview of Methods and Tools for Transfection of Eukaryotic Cells in vitro. Front Bioeng Biotechnol 2021; 9:701031. [PMID: 34354988 PMCID: PMC8330802 DOI: 10.3389/fbioe.2021.701031] [Citation(s) in RCA: 61] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 06/28/2021] [Indexed: 11/13/2022] Open
Abstract
Transfection is a powerful analytical tool enabling studies of gene products and functions in eukaryotic cells. Successful delivery of genetic material into cells depends on DNA quantity and quality, incubation time and ratio of transfection reagent to DNA, the origin, type and the passage of transfected cells, and the presence or absence of serum in the cell culture. So far a number of transfection methods that use viruses, non-viral particles or physical factors as the nucleic acids carriers have been developed. Among non-viral carriers, the cationic polymers are proposed as the most attractive ones due to the possibility of their chemical structure modification, low toxicity and immunogenicity. In this review the delivery systems as well as physical, biological and chemical methods used for eukaryotic cells transfection are described and discussed.
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Affiliation(s)
- Agnieszka Fus-Kujawa
- Department of Molecular Biology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, Katowice, Poland
| | - Pawel Prus
- Department of Molecular Biology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, Katowice, Poland
- Students’ Scientific Society, Katowice, Poland
| | - Karolina Bajdak-Rusinek
- Department of Medical Genetics, Faculty of Medical Sciences in Katowice, Medical University of Silesia, Katowice, Poland
| | - Paulina Teper
- Centre of Polymer and Carbon Materials, Polish Academy of Sciences, Zabrze, Poland
| | - Katarzyna Gawron
- Department of Molecular Biology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, Katowice, Poland
| | - Agnieszka Kowalczuk
- Centre of Polymer and Carbon Materials, Polish Academy of Sciences, Zabrze, Poland
| | - Aleksander L. Sieron
- Department of Molecular Biology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, Katowice, Poland
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Chong ZX, Yeap SK, Ho WY. Transfection types, methods and strategies: a technical review. PeerJ 2021; 9:e11165. [PMID: 33976969 PMCID: PMC8067914 DOI: 10.7717/peerj.11165] [Citation(s) in RCA: 89] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 03/05/2021] [Indexed: 12/17/2022] Open
Abstract
Transfection is a modern and powerful method used to insert foreign nucleic acids into eukaryotic cells. The ability to modify host cells' genetic content enables the broad application of this process in studying normal cellular processes, disease molecular mechanism and gene therapeutic effect. In this review, we summarized and compared the findings from various reported literature on the characteristics, strengths, and limitations of various transfection methods, type of transfected nucleic acids, transfection controls and approaches to assess transfection efficiency. With the vast choices of approaches available, we hope that this review will help researchers, especially those new to the field, in their decision making over the transfection protocol or strategy appropriate for their experimental aims.
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Affiliation(s)
- Zhi Xiong Chong
- School of Pharmacy, University of Nottingham Malaysia, Semenyih, Selangor, Malaysia
| | - Swee Keong Yeap
- China-ASEAN College of Marine Sciences, Xiamen University Malaysia, Sepang, Selangor, Malaysia
| | - Wan Yong Ho
- School of Pharmacy, University of Nottingham Malaysia, Semenyih, Selangor, Malaysia
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10
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Approaches for the sensitive detection of rare base and prime editing events. Methods 2021; 194:75-82. [PMID: 33484827 DOI: 10.1016/j.ymeth.2021.01.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Revised: 01/11/2021] [Accepted: 01/18/2021] [Indexed: 12/23/2022] Open
Abstract
Precision chemistry entailing user-directed nucleotide substitutions and template-specified repair can be facilitated by base editing and prime editing, respectively. Recently, the diversification of adenine, cytosine, and prime editor variants obliges a considered, high-throughput evaluation of these tools for optimized, end-point applications. Herein, we outline novel, cost-effective and scalable approaches for the rapid detection of base editing and prime editing outcomes using gel electrophoresis. For base editing, we exploit primer mismatch amplification (SNP genotyping) for the gel-based detection of base editing efficiencies as low as 0.1%. For prime editing, we describe a one-pot reaction combining polymerase chain reaction (PCR) amplification of the target region with restriction digestion (restriction fragment length polymorphism; RFLP). RFLP enables the rapid detection of insertion or deletion events in under 2.5 h from genomic DNA extraction. We show that our method of SNP genotyping is amenable to both endogenous target loci as well as transfected, episomal plasmid targets in BHK-21 cells. Next, we validate the incidence of base and prime editing by describing Sanger sequencing and next-generation sequencing (NGS) workflows for the accurate validation and quantification of on-target editing efficiencies. Our workflow details three different methods for the detection of rare base and prime editing events, enabling a tiered approach from low to high resolution that makes use of gel electrophoresis, Sanger sequencing, and NGS.
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11
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Nandi S, Kale N, Patil A, Banerjee S, Patil Y, Khandare J. A graphene-sandwiched DNA nano-system: regulation of intercalated doxorubicin for cellular localization. NANOSCALE ADVANCES 2020; 2:5746-5759. [PMID: 36133866 PMCID: PMC9417510 DOI: 10.1039/d0na00575d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 10/05/2020] [Indexed: 06/16/2023]
Abstract
Control of the sub-cellular localization of nanoparticles (NPs) with enhanced drug-loading capacity, employing graphene oxide (GO), iron oxide (Fe3O4) NPs and sandwiched deoxyribonucleic acid (DNA) bearing intercalated anticancer drug doxorubicin (DOX) has been investigated in this work. The nanosystems G-DNA-DOX-Fe3O4 and Fe3O4-DNA-DOX differentially influence serum protein binding and deliver DOX to lysosomal compartments of cervical cancer (HeLa) cells with enhanced retention. Stern-Volmer plots describing BSA adsorption on the nanosystems demonstrated the quenching constants, K sv for G-DNA-DOX-Fe3O4 and Fe3O4-DNA-DOX (0.025 mL μg-1 and 0.0103 mL μg-1 respectively). Nuclear DOX intensity, measured at 24 h, was ∼2.0 fold higher for Fe3O4-DNA-DOX in HeLa cells. Parallelly, the cytosol displayed ∼2.2 fold higher DOX intensity for Fe3O4-DNA-DOX compared to G-DNA-DOX-Fe3O4. Fe3O4-DNA-DOX was more efficacious in the cytotoxic effect than G-DNA-DOX-Fe3O4 (viability of treated cells: 33% and 49% respectively). The DNA:nanosystems demonstrated superior cytotoxicity compared to mole-equivalent free DOX administration. The results implicate DNA:DOX NPs in influencing the cellular uptake mechanism and were critically subject to cellular localization. Furthermore, cell morphology analysis evidenced maximum deformation attributed to free-DOX with 34% increased cell roundness, 63% decreased cell area and ∼1.9 times increased nuclear-to-cytoplasmic (N/C) ratio after 24 h. In the case of Fe3O4-DNA-DOX, the N/C ratio increased 1.2 times and a maximum ∼37% decrease in NSA was noted suggesting involvement of non-canonical cytotoxic pathways. In conclusion, the study makes a case for designing nanosystems with controlled and regulated sub-cellular localization to potentially exploit secondary cytotoxic pathways, in addition to optimized drug-loading for enhanced anticancer efficacy and reduced adverse effects.
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Affiliation(s)
- Semonti Nandi
- MAEER's Maharashtra Institute of Pharmacy Kothrud Pune 411038 India
- School of Pharmacy, Dr Vishwanath Karad MIT World Peace University MIT Campus, S. No. 124, Paud Road, Kothrud Pune 411038 India
| | - Narendra Kale
- MAEER's Maharashtra Institute of Pharmacy Kothrud Pune 411038 India
- School of Pharmacy, Dr Vishwanath Karad MIT World Peace University MIT Campus, S. No. 124, Paud Road, Kothrud Pune 411038 India
| | - Ashwini Patil
- MAEER's Maharashtra Institute of Pharmacy Kothrud Pune 411038 India
- School of Pharmacy, Dr Vishwanath Karad MIT World Peace University MIT Campus, S. No. 124, Paud Road, Kothrud Pune 411038 India
| | - Shashwat Banerjee
- Maharashtra Institute of Medical Education and Research Medical College Talegaon Dabhade Pune 410507 India
| | - Yuvraj Patil
- Maharashtra Institute of Medical Education and Research Medical College Talegaon Dabhade Pune 410507 India
| | - Jayant Khandare
- School of Pharmacy, Dr Vishwanath Karad MIT World Peace University MIT Campus, S. No. 124, Paud Road, Kothrud Pune 411038 India
- School of Consciousness, Dr Vishwanath Karad MIT World Peace University MIT Campus, S. No. 124, Paud Road, Kothrud Pune 411038 India
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12
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Orefice NS. Development of New Strategies Using Extracellular Vesicles Loaded with Exogenous Nucleic Acid. Pharmaceutics 2020; 12:E705. [PMID: 32722622 PMCID: PMC7464422 DOI: 10.3390/pharmaceutics12080705] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 07/19/2020] [Accepted: 07/24/2020] [Indexed: 12/13/2022] Open
Abstract
Gene therapy is a therapeutic strategy of delivering foreign genetic material (encoding for an important protein) into a patient's target cell to replace a defective gene. Nucleic acids are embedded within the adeno-associated virus (AAVs) vectors; however, preexisting immunity to AAVs remains a significant concern that impairs their clinical application. Extracellular vesicles (EVs) hold great potential for therapeutic applications as vectors of nucleic acids due to their endogenous intercellular communication functions through their cargo delivery, including lipids and proteins. So far, small RNAs (siRNA and micro (mi)RNA) have been mainly loaded into EVs to treat several diseases, but the potential use of EVs to load and deliver exogenous plasmid DNA has not been thoroughly described. This review provides a comprehensive overview of the principal methodologies currently employed to load foreign genetic material into EVs, highlighting the need to find the most effective strategies for their successful clinical translations.
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Affiliation(s)
- Nicola Salvatore Orefice
- Department of Medicine, University of Wisconsin-Madison, Madison, WI 53705, USA; or ; Tel.: +1-608-262-21-89
- Waisman Center, University of Wisconsin-Madison, Madison, WI 53705, USA
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13
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Fischbach A, Krüger A, Hampp S, Assmann G, Rank L, Hufnagel M, Stöckl MT, Fischer JMF, Veith S, Rossatti P, Ganz M, Ferrando-May E, Hartwig A, Hauser K, Wiesmüller L, Bürkle A, Mangerich A. The C-terminal domain of p53 orchestrates the interplay between non-covalent and covalent poly(ADP-ribosyl)ation of p53 by PARP1. Nucleic Acids Res 2019; 46:804-822. [PMID: 29216372 PMCID: PMC5778597 DOI: 10.1093/nar/gkx1205] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Accepted: 11/22/2017] [Indexed: 01/25/2023] Open
Abstract
The post-translational modification poly(ADP-ribosyl)ation (PARylation) plays key roles in genome maintenance and transcription. Both non-covalent poly(ADP-ribose) binding and covalent PARylation control protein functions, however, it is unknown how the two modes of modification crosstalk mechanistically. Employing the tumor suppressor p53 as a model substrate, this study provides detailed insights into the interplay between non-covalent and covalent PARylation and unravels its functional significance in the regulation of p53. We reveal that the multifunctional C-terminal domain (CTD) of p53 acts as the central hub in the PARylation-dependent regulation of p53. Specifically, p53 bound to auto-PARylated PARP1 via highly specific non–covalent PAR-CTD interaction, which conveyed target specificity for its covalent PARylation by PARP1. Strikingly, fusing the p53-CTD to a protein that is normally not PARylated, renders this a target for covalent PARylation as well. Functional studies revealed that the p53–PAR interaction had substantial implications on molecular and cellular levels. Thus, PAR significantly influenced the complex p53–DNA binding properties and controlled p53 functions, with major implications on the p53-dependent interactome, transcription, and replication-associated recombination. Remarkably, this mechanism potentially also applies to other PARylation targets, since a bioinformatics analysis revealed that CTD-like regions are highly enriched in the PARylated proteome.
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Affiliation(s)
- Arthur Fischbach
- Department of Biology, University of Konstanz, 78457 Konstanz, Germany.,Konstanz Research School Chemical Biology, University of Konstanz, 78457 Konstanz, Germany
| | - Annika Krüger
- Department of Biology, University of Konstanz, 78457 Konstanz, Germany.,Konstanz Research School Chemical Biology, University of Konstanz, 78457 Konstanz, Germany.,Department of Chemistry, University of Konstanz, 78457 Konstanz, Germany
| | - Stephanie Hampp
- Department of Obstetrics and Gynaecology, University of Ulm, 89075 Ulm, Germany
| | - Greta Assmann
- Department of Biology, University of Konstanz, 78457 Konstanz, Germany.,Konstanz Research School Chemical Biology, University of Konstanz, 78457 Konstanz, Germany
| | - Lisa Rank
- Department of Biology, University of Konstanz, 78457 Konstanz, Germany
| | - Matthias Hufnagel
- Department of Food Chemistry and Toxicology, Institute for Applied Biosciences, Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe, Germany
| | - Martin T Stöckl
- Bioimaging Center, Department of Biology, University of Konstanz, 78457 Konstanz, Germany
| | - Jan M F Fischer
- Department of Biology, University of Konstanz, 78457 Konstanz, Germany.,Konstanz Research School Chemical Biology, University of Konstanz, 78457 Konstanz, Germany
| | - Sebastian Veith
- Department of Biology, University of Konstanz, 78457 Konstanz, Germany.,Research Training Group 1331, University of Konstanz, 78457 Konstanz, Germany
| | - Pascal Rossatti
- Department of Biology, University of Konstanz, 78457 Konstanz, Germany
| | - Magdalena Ganz
- Bioimaging Center, Department of Biology, University of Konstanz, 78457 Konstanz, Germany
| | - Elisa Ferrando-May
- Bioimaging Center, Department of Biology, University of Konstanz, 78457 Konstanz, Germany
| | - Andrea Hartwig
- Department of Food Chemistry and Toxicology, Institute for Applied Biosciences, Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe, Germany
| | - Karin Hauser
- Department of Chemistry, University of Konstanz, 78457 Konstanz, Germany
| | - Lisa Wiesmüller
- Department of Obstetrics and Gynaecology, University of Ulm, 89075 Ulm, Germany
| | - Alexander Bürkle
- Department of Biology, University of Konstanz, 78457 Konstanz, Germany
| | - Aswin Mangerich
- Department of Biology, University of Konstanz, 78457 Konstanz, Germany
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14
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Dolgova EV, Evdokimov AN, Proskurina AS, Efremov YR, Bayborodin SI, Potter EA, Popov AA, Petruseva IO, Lavrik OI, Bogachev SS. Double-Stranded DNA Fragments Bearing Unrepairable Lesions and Their Internalization into Mouse Krebs-2 Carcinoma Cells. Nucleic Acid Ther 2019; 29:278-290. [PMID: 31194620 DOI: 10.1089/nat.2019.0786] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Murine Krebs-2 tumor-initiating stem cells are known to natively internalize extracellular double-stranded DNA fragments. Being internalized, these fragments interfere in the repair of chemically induced interstrand cross-links. In the current investigation, 756 bp polymerase chain reaction (PCR) product containing bulky photoreactive dC adduct was used as extracellular DNA. This adduct was shown to inhibit the cellular system of nucleotide excision repair while being resistant to excision by this DNA repair system. The basic parameters for this DNA probe internalization by the murine Krebs-2 tumor cells were characterized. Being incubated under regular conditions (60 min, 24°C, 500 μL of the incubation medium, in the dark), 0.35% ± 0.18% of the Krebs-2 ascites cells were shown to natively internalize modified DNA. The saturating amount of the modified DNA was detected to be 0.37 μg per 106 cells. For the similar unmodified DNA fragments, this ratio is 0.73 μg per 106 cells. Krebs-2 tumor cells were shown to be saturated internalizing either (190 ± 40) × 103 molecules of modified DNA or (1,000 ± 100) × 103 molecules of native DNA. On internalization, the fragments of DNA undergo partial and nonuniform hydrolysis of 3' ends followed by circularization. The degree of hydrolysis, assessed by sequencing of several clones with the insertion of specific PCR product, was 30-60 nucleotides.
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Affiliation(s)
- Evgeniya V Dolgova
- Laboratory of Induced Cell Processes, Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
| | - Alexey N Evdokimov
- Laboratory of Bioorganic Chemistry of Enzymes, Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
| | - Anastasia S Proskurina
- Laboratory of Induced Cell Processes, Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
| | - Yaroslav R Efremov
- Laboratory of Induced Cell Processes, Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia.,Natural Sciences Department, Novosibirsk State University, Novosibirsk, Russia
| | - Sergey I Bayborodin
- Laboratory of Induced Cell Processes, Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
| | - Ekaterina A Potter
- Laboratory of Induced Cell Processes, Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
| | - Alexey A Popov
- Laboratory of Bioorganic Chemistry of Enzymes, Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
| | - Irina O Petruseva
- Laboratory of Bioorganic Chemistry of Enzymes, Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
| | - Olga I Lavrik
- Laboratory of Bioorganic Chemistry of Enzymes, Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia.,Natural Sciences Department, Novosibirsk State University, Novosibirsk, Russia.,Department of Physical Chemistry and Biotechnology, Altai State University, Barnaul, Russia
| | - Sergey S Bogachev
- Laboratory of Induced Cell Processes, Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
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15
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Ung CY, Guo F, Zhang X, Zhu Z, Zhu S. Mosaic zebrafish transgenesis for functional genomic analysis of candidate cooperative genes in tumor pathogenesis. J Vis Exp 2015:52567. [PMID: 25867597 PMCID: PMC4401404 DOI: 10.3791/52567] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Comprehensive genomic analysis has uncovered surprisingly large numbers of genetic alterations in various types of cancers. To robustly and efficiently identify oncogenic "drivers" among these tumors and define their complex relationships with concurrent genetic alterations during tumor pathogenesis remains a daunting task. Recently, zebrafish have emerged as an important animal model for studying human diseases, largely because of their ease of maintenance, high fecundity, obvious advantages for in vivo imaging, high conservation of oncogenes and their molecular pathways, susceptibility to tumorigenesis and, most importantly, the availability of transgenic techniques suitable for use in the fish. Transgenic zebrafish models of cancer have been widely used to dissect oncogenic pathways in diverse tumor types. However, developing a stable transgenic fish model is both tedious and time-consuming, and it is even more difficult and more time-consuming to dissect the cooperation of multiple genes in disease pathogenesis using this approach, which requires the generation of multiple transgenic lines with overexpression of the individual genes of interest followed by complicated breeding of these stable transgenic lines. Hence, use of a mosaic transient transgenic approach in zebrafish offers unique advantages for functional genomic analysis in vivo. Briefly, candidate transgenes can be coinjected into one-cell-stage wild-type or transgenic zebrafish embryos and allowed to integrate together into each somatic cell in a mosaic pattern that leads to mixed genotypes in the same primarily injected animal. This permits one to investigate in a faster and less expensive manner whether and how the candidate genes can collaborate with each other to drive tumorigenesis. By transient overexpression of activated ALK in the transgenic fish overexpressing MYCN, we demonstrate here the cooperation of these two oncogenes in the pathogenesis of a pediatric cancer, neuroblastoma that has resisted most forms of contemporary treatment.
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Affiliation(s)
- Choong Yong Ung
- Department of Molecular Pharmacology & Experimental Therapeutics, Mayo Clinic College of Medicine, Center for Individualized Medicine
| | - Feng Guo
- Tufts University School of Medicine
| | - Xiaoling Zhang
- Department of Biochemistry and Molecular Biology, Mayo Clinic
| | - Zhihui Zhu
- Department of Biochemistry and Molecular Biology, Mayo Clinic
| | - Shizhen Zhu
- Department of Molecular Pharmacology & Experimental Therapeutics, Mayo Clinic College of Medicine, Center for Individualized Medicine; Department of Biochemistry and Molecular Biology, Mayo Clinic;
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16
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Zelensky AN, Sanchez H, Ristic D, Vidic I, van Rossum-Fikkert SE, Essers J, Wyman C, Kanaar R. Caffeine suppresses homologous recombination through interference with RAD51-mediated joint molecule formation. Nucleic Acids Res 2013; 41:6475-89. [PMID: 23666627 PMCID: PMC3711438 DOI: 10.1093/nar/gkt375] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Caffeine is a widely used inhibitor of the protein kinases that play a central role in the DNA damage response. We used chemical inhibitors and genetically deficient mouse embryonic stem cell lines to study the role of DNA damage response in stable integration of the transfected DNA and found that caffeine rapidly, efficiently and reversibly inhibited homologous integration of the transfected DNA as measured by several homologous recombination-mediated gene-targeting assays. Biochemical and structural biology experiments revealed that caffeine interfered with a pivotal step in homologous recombination, homologous joint molecule formation, through increasing interactions of the RAD51 nucleoprotein filament with non-homologous DNA. Our results suggest that recombination pathways dependent on extensive homology search are caffeine-sensitive and stress the importance of considering direct checkpoint-independent mechanisms in the interpretation of the effects of caffeine on DNA repair.
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Affiliation(s)
- Alex N Zelensky
- Department of Cell Biology and Genetics, Cancer Genomics Center, Erasmus Medical Center, PO Box 2040, 3000 CA, Rotterdam, The Netherlands
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17
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Papaioannou I, Simons JP, Owen JS. Oligonucleotide-directed gene-editing technology: mechanisms and future prospects. Expert Opin Biol Ther 2012; 12:329-42. [PMID: 22321001 DOI: 10.1517/14712598.2012.660522] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
INTRODUCTION Gene editing, as defined here, uses short synthetic oligonucleotides to introduce small, site-specific changes into mammalian genomes, including repair of genetic point mutations. Early RNA-DNA oligonucleotides (chimeraplasts) were problematic, but application of single-stranded all-DNA molecules (ssODNs) has matured the technology into a reproducible tool with therapeutic potential. AREAS COVERED The review illustrates how gene-editing mechanisms are linked to DNA repair systems and DNA replication, and explains that while homologous recombination (HR) and nucleotide excision repair (NER) are implicated, the mismatch repair (MMR) system is inhibitory. Although edited cells often arrest in late S-phase or G2-phase, alternative ssODN chemistries can improve editing efficiency and cell viability. The final section focuses on the exciting tandem use of ssODNs with zinc finger nucleases to achieve high frequency genome editing. EXPERT OPINION For a decade, changing the genetic code of cells via ssODNs was largely done in reporter gene systems to optimize methods and as proof-of-principle. Today, editing endogenous genes is advancing, driven by a clearer understanding of mechanisms, by effective ssODN designs and by combination with engineered endonuclease technologies. Success is becoming routine in vitro and ex vivo, which includes editing embryonic stem (ES) and induced pluripotent stem (iPS) cells, suggesting that in vivo organ gene editing is a future option.
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Affiliation(s)
- Ioannis Papaioannou
- UCL Medical School, Division of Medicine (Upper 3rd Floor), Royal Free Campus, Rowland Hill Street, London NW3 2PF, UK
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18
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Iwaizumi M, Tseng-Rogenski S, Carethers JM. DNA mismatch repair proficiency executing 5-fluorouracil cytotoxicity in colorectal cancer cells. Cancer Biol Ther 2011; 12:756-64. [PMID: 21814034 DOI: 10.4161/cbt.12.8.17169] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND 5-fluorouracil (5FU)-based chemotherapy is the standard treatment for advanced stage colorectal cancer (CRC) patients. Several groups including ours have reported that stage II-III colorectal cancer patients whose tumors retain DNA Mismatch repair (MMR) function derive a benefit from 5FU, but patients with tumors that lost MMR function do not. Although MMR recognition of 5FU incorporated in DNA has been demonstrated biochemically, it has not been demonstrated within cells to execute 5FU cytotoxicity. AIM To establish an efficient construction model for 5FU within DNA and demonstrate that 5FU incorporated into DNA can trigger cellular cytotoxicity executed by the DNA MMR system. METHODS We constructed a 5FdU-containing heteroduplex plasmid (5FdU plasmid) and 5FdU-containing linear dsDNA (5FdU linear DNA), and transfected these into MMR-proficient, hMLH1-/- and hMSH6-/- cells. We observed cell growth characteristics of both transfectants for 5FU-induced cytotoxicity. RESULTS MMR- proficient cells transfected with the 5FdU plasmid but not the 5FdU linear DNA showed reduced cell proliferation by MTS and clonogenic assays, and demonstrated cell morphological change consistent with apoptosis. In MMR-deficient cells, neither the 5FdU plasmid nor 5FdU linear DNA induced cell growth or morphological changes different from controls. CONCLUSION 5FdU as heteroduplex DNA in plasmid but not linear form triggered cytotoxicity in a MMR-dependent manner. Thus 5FU incorporated into DNA, separated from its effects on RNA, can be recognized by DNA MMR to trigger cell death.
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Affiliation(s)
- Moriya Iwaizumi
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
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19
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Farley EK, Gale E, Chambers D, Li M. Effects of in ovo electroporation on endogenous gene expression: genome-wide analysis. Neural Dev 2011; 6:17. [PMID: 21527010 PMCID: PMC3105949 DOI: 10.1186/1749-8104-6-17] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2010] [Accepted: 04/28/2011] [Indexed: 11/23/2022] Open
Abstract
Background In ovo electroporation is a widely used technique to study gene function in developmental biology. Despite the widespread acceptance of this technique, no genome-wide analysis of the effects of in ovo electroporation, principally the current applied across the tissue and exogenous vector DNA introduced, on endogenous gene expression has been undertaken. Here, the effects of electric current and expression of a GFP-containing construct, via electroporation into the midbrain of Hamburger-Hamilton stage 10 chicken embryos, are analysed by microarray. Results Both current alone and in combination with exogenous DNA expression have a small but reproducible effect on endogenous gene expression, changing the expression of the genes represented on the array by less than 0.1% (current) and less than 0.5% (current + DNA), respectively. The subset of genes regulated by electric current and exogenous DNA span a disparate set of cellular functions. However, no genes involved in the regional identity were affected. In sharp contrast to this, electroporation of a known transcription factor, Dmrt5, caused a much greater change in gene expression. Conclusions These findings represent the first systematic genome-wide analysis of the effects of in ovo electroporation on gene expression during embryonic development. The analysis reveals that this process has minimal impact on the genetic basis of cell fate specification. Thus, the study demonstrates the validity of the in ovo electroporation technique to study gene function and expression during development. Furthermore, the data presented here can be used as a resource to refine the set of transcriptional responders in future in ovo electroporation studies of specific gene function.
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Affiliation(s)
- Emma K Farley
- MRC Clinical Sciences Centre, Imperial College London, W12 0NN, UK.
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20
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Sargent RG, Kim S, Gruenert DC. Oligo/polynucleotide-based gene modification: strategies and therapeutic potential. Oligonucleotides 2011; 21:55-75. [PMID: 21417933 DOI: 10.1089/oli.2010.0273] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Oligonucleotide- and polynucleotide-based gene modification strategies were developed as an alternative to transgene-based and classical gene targeting-based gene therapy approaches for treatment of genetic disorders. Unlike the transgene-based strategies, oligo/polynucleotide gene targeting approaches maintain gene integrity and the relationship between the protein coding and gene-specific regulatory sequences. Oligo/polynucleotide-based gene modification also has several advantages over classical vector-based homologous recombination approaches. These include essentially complete homology to the target sequence and the potential to rapidly engineer patient-specific oligo/polynucleotide gene modification reagents. Several oligo/polynucleotide-based approaches have been shown to successfully mediate sequence-specific modification of genomic DNA in mammalian cells. The strategies involve the use of polynucleotide small DNA fragments, triplex-forming oligonucleotides, and single-stranded oligodeoxynucleotides to mediate homologous exchange. The primary focus of this review will be on the mechanistic aspects of the small fragment homologous replacement, triplex-forming oligonucleotide-mediated, and single-stranded oligodeoxynucleotide-mediated gene modification strategies as it relates to their therapeutic potential.
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Affiliation(s)
- R Geoffrey Sargent
- Department of Otolaryngology-Head and Neck Surgery, University of California , San Francisco, California 94115, USA
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21
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EMSY overexpression disrupts the BRCA2/RAD51 pathway in the DNA-damage response: implications for chromosomal instability/recombination syndromes as checkpoint diseases. Mol Genet Genomics 2011; 285:325-40. [PMID: 21409565 PMCID: PMC3064890 DOI: 10.1007/s00438-011-0612-5] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2010] [Accepted: 02/27/2011] [Indexed: 11/05/2022]
Abstract
EMSY links the BRCA2 pathway to sporadic breast/ovarian cancer. It encodes a nuclear protein that binds to the BRCA2 N-terminal domain implicated in chromatin/transcription regulation, but when sporadically amplified/overexpressed, increased EMSY level represses BRCA2 transactivation potential and induces chromosomal instability, mimicking the activity of BRCA2 mutations in the development of hereditary breast/ovarian cancer. In addition to chromatin/transcription regulation, EMSY may also play a role in the DNA-damage response, suggested by its ability to localize at chromatin sites of DNA damage/repair. This implies that EMSY overexpression may also repress BRCA2 in DNA-damage replication/checkpoint and recombination/repair, coordinated processes that also require its interacting proteins: PALB2, the partner and localizer of BRCA2; RPA, replication/checkpoint protein A; and RAD51, the inseparable recombination/repair enzyme. Here, using a well-characterized recombination/repair assay system, we demonstrate that a slight increase in EMSY level can indeed repress these two processes independently of transcriptional interference/repression. Since EMSY, RPA and PALB2 all bind to the same BRCA2 region, these findings further support a scenario wherein: (a) EMSY amplification may mimic BRCA2 deficiency, at least by overriding RPA and PALB2, crippling the BRCA2/RAD51 complex at DNA-damage and replication/transcription sites; and (b) BRCA2/RAD51 may coordinate these processes by employing at least EMSY, PALB2 and RPA. We extensively discuss the molecular details of how this can happen to ascertain its implications for a novel recombination mechanism apparently conceived as checkpoint rather than a DNA repair system for cell division, survival, death, and human diseases, including the tissue specificity of cancer predisposition, which may renew our thinking about targeted therapy and prevention.
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22
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Vilaysane A, Muruve DA. The innate immune response to DNA. Semin Immunol 2009; 21:208-14. [DOI: 10.1016/j.smim.2009.05.006] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2009] [Accepted: 05/06/2009] [Indexed: 12/25/2022]
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23
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Trollet C, Athanasopoulos T, Popplewell L, Malerba A, Dickson G. Gene therapy for muscular dystrophy: current progress and future prospects. Expert Opin Biol Ther 2009; 9:849-66. [DOI: 10.1517/14712590903029164] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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24
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Wuepping M, Kenner O, Hegele H, Schwandt S, Kaufmann D. Higher efficiency of thymine-adenine clamp-modified single-stranded oligonucleotides in targeted nucleotide sequence correction is not correlated with lower intracellular degradation. Hum Gene Ther 2009; 20:283-7. [PMID: 19061415 DOI: 10.1089/hum.2008.138] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Specific single-stranded oligonucleotides can induce targeted nucleotide sequence correction in eukaryotic genes in vitro and in vivo. Our model for investigating the reasons for the low correction rates achieved by this method is the correction of a point mutation in the hypoxanthine-guanine phosphoribosyltransferase gene (hprt) in the cell line V79-151. Using single-stranded phosphorothioate-modified oligonucleotides, the correction rates of this hprt mutation were low but always reproducible. One reason for low exchange rates may be fast intracellular degradation of the oligonucleotides. Therefore we compared the exchange rates of different 3' and 5' end-modified oligonucleotides with their degradation rates. Thymine-adenine (TA) repeat (clamp)-modified oligonucleotides showed higher correction rates than those with a guanine-cytosine (GC) clamp and 5' clamps induced higher correction rates than clamps at the 3' end. Experiments on the stability of the most effective 5'-TA and 3'-TA clamp-modified oligonucleotide indicated rapid cleavage and the occurrence of shortened oligonucleotides in the presence of cytoplasmic and nuclear extracts. The phosphorothioate-modified oligonucleotides were more stable, but their correction rates were lower. We suggest that there is no direct correlation between the biological stability of the full-length oligonucleotides and the exchange rates achieved.
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Affiliation(s)
- M Wuepping
- Institute of Human Genetics, University of Ulm, Albert-Einstein-Allee 11, Ulm, Germany
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25
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Igoucheva O, Alexeev V, Anni H, Rubin E. Oligonucleotide-mediated gene targeting in human hepatocytes: implications of mismatch repair. Oligonucleotides 2008; 18:111-22. [PMID: 18637729 DOI: 10.1089/oli.2008.0120] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Gene therapy using viral vectors for liver diseases, particularly congenital disorders, is besought with difficulties, particularly immunologic reactions to viral antigens. As a result, nonviral methods for gene transfer in hepatocytes have also been explored. Gene repair by small synthetic single-stranded oligodeoxynucleotides (ODNs) produces targeted alterations in the genome of mammalian cells and represents a great potential for nonviral gene therapy. To test the feasibility of ODN-mediated gene repair within chromosomal DNA in human hepatocytes, two new cell lines with stably integrated mutant reporter genes, namely neomycin and enhanced green fluorescent protein were established. Targeting theses cells with ODNs specifically designed for repair resulted in site-directed and permanent gene conversion of the single-point mutation of the reporter genes. Moreover, the frequency of gene alteration was highly dependent on the mitotic activity of the cells, indicating that the proliferative status is an important factor for successful targeting in human hepatocytes. cDNA array expression profiling of DNA repair genes under different cell culture conditions combined with RNA interference assay showed that mismatch repair (MMR) in actively growing hepatocytes imposes a strong barrier to efficient gene repair mediated by ODNs. Suppression of MSH2 activity in hepatocytes transduced with short hairpin RNAs (shRNAs) targeted to MSH2 mRNA resulted in 25- to 30-fold increase in gene repair rate, suggesting a negative effect of MMR on ODN-mediated gene repair. Taken together, these data suggest that under appropriate conditions nonviral chromosomal targeting may represent a feasible approach to gene therapy in liver disease.
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Affiliation(s)
- Olga Igoucheva
- Department of Dermatology and Cutaneous Biology, Anatomy and Cell Biology, Jefferson Medical College, Thomas Jefferson University, Philadelphia, PA19107, USA.
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26
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Crinelli R, Bianchi M, Menotta M, Carloni E, Giacomini E, Pennati M, Magnani M. Ubiquitin over-expression promotes E6AP autodegradation and reactivation of the p53/MDM2 pathway in HeLa cells. Mol Cell Biochem 2008; 318:129-45. [DOI: 10.1007/s11010-008-9864-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2008] [Accepted: 06/25/2008] [Indexed: 10/21/2022]
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27
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Site-specific gene modification by oligodeoxynucleotides in mouse bone marrow-derived mesenchymal stem cells. Gene Ther 2008; 15:1035-48. [PMID: 18337839 DOI: 10.1038/gt.2008.31] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Synthetic oligodeoxynucleotides (ODNs) had been employed in gene modification and represent an alternative approach to 'cure' genetic disorders caused by mutations. To test the ability of ODN-mediated gene repair in bone marrow-derived mesenchymal stem cells (MSCs), we established MSCs cell lines with stably integrated mutant neomycin resistance and enhanced green fluorescent protein reporter genes. The established cultures showed morphologically homogenous population with phenotypic and functional features of mesenchymal progenitors. Transfection with gene-specific ODNs successfully repaired targeted cells resulting in the expression of functional proteins at relatively high frequency approaching 0.2%. Direct DNA sequencing confirmed that phenotype change resulted from the designated nucleotide correction at the target site. The position of the mismatch-forming nucleotide was shown to be important structural feature for ODN repair activity. The genetically corrected MSCs were healthy and maintained an undifferentiated state. Furthermore, the genetically modified MSCs were able to engraft into many tissues of unconditioned transgenic mice making them an attractive therapeutic tool in a wide range of clinical applications.
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Parekh-Olmedo H, Kmiec EB. Progress and Prospects: targeted gene alteration (TGA). Gene Ther 2007; 14:1675-80. [DOI: 10.1038/sj.gt.3303053] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Wang Z, Zhou ZJ, Liu DP, Huang JD. Single-stranded oligonucleotide-mediated gene repair in mammalian cells has a mechanism distinct from homologous recombination repair. Biochem Biophys Res Commun 2006; 350:568-73. [PMID: 17026965 DOI: 10.1016/j.bbrc.2006.09.078] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2006] [Accepted: 09/17/2006] [Indexed: 11/30/2022]
Abstract
Single-stranded DNA oligonucleotide (SSO)-mediated gene repair has great potentials for gene therapy and functional genomic studies. However, its underlying mechanism remains unclear. Previous studies from other groups have suggested that DNA damage response via the ATM/ATR pathway may be involved in this process. In this study, we measured the effect of two ATM/ATR inhibitors caffeine and pentoxifylline on the correction efficiency in SSO-mediated gene repair. We also checked their effect on double-stranded break (DSB)-induced homologous recombination repair (HRR) as a control, which is well known to be dependent on the ATM/ATR pathway. We found these inhibitors could completely inhibit DSB-induced HRR, but could only partially inhibit SSO-mediated process, indicating SSO-mediated gene repair is not dependent on the ATM/ATR pathway. Furthermore, we found that thymidine treatment promotes SSO-mediated gene repair, but inhibits DSB-induced HRR. Collectively, our results demonstrate that SSO-mediated and DSB-induced gene repairs have distinct mechanisms.
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Affiliation(s)
- Zai Wang
- Department of Biochemistry, The University of Hong Kong, 3/F Laboratory Block, Faculty of Medicine Building, 21 Sassoon Road, Pokfulam, Hong Kong SAR, China
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Igoucheva O, Alexeev V, Scharer O, Yoon K. Involvement of ERCC1/XPF and XPG in oligodeoxynucleotide-directed gene modification. Oligonucleotides 2006; 16:94-104. [PMID: 16584298 DOI: 10.1089/oli.2006.16.94] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Oligodeoxynucleotide (ODN)-mediated gene alteration was postulated to occur in two steps, DNA strand pairing and DNA repair. Once alignment has occurred through homologous strand pairing, a single mismatch is formed between an oligonucleotide and one of the target strands. Because of this mismatch, it has been suggested that proteins involved in a mismatch repair pathway (MMR) participate in the process. We proposed an alternative model, in which a transient assimilation of ODN to the target DNA can interrupt the trafficking of RNA polymerase, and the stalled RNA polymerase may signal for recruitment of DNA repair proteins, including transcription-coupled (TCR) DNA repair and nucleotide excision repair (NER) pathways. Recently, we found that transcription of many genes participating in NER and MMR was induced by the presence of plasmid DNA, and the extent of induction correlated with episomal gene repair rates. To investigate whether an increased level of induction of genes involved in specific DNA repair pathways has a functional role in ODN-directed gene repair, we performed episomal targeting in several cell lines with a specific defective gene in NER and MMR pathways. Comparison among several genetically related cell lines harboring a specific defective gene and complementation of missing activities showed that a primary pathway for gene correction involves some of the proteins participating in NER, primarily two endonucleases processing a DNA lesion, but not MMR.
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Affiliation(s)
- Olga Igoucheva
- Department of Dermatology and Cutaneous Biology, Thomas Jefferson University Jefferson Medical College, Philadelphia, PA 19107, USA
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Kuzmiak HA, Maquat LE. Applying nonsense-mediated mRNA decay research to the clinic: progress and challenges. Trends Mol Med 2006; 12:306-16. [PMID: 16782405 DOI: 10.1016/j.molmed.2006.05.005] [Citation(s) in RCA: 186] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2006] [Revised: 04/18/2006] [Accepted: 05/22/2006] [Indexed: 11/15/2022]
Abstract
Premature termination codons (PTCs) are equivalent to nonsense sequences. They encode no amino acid, and their presence precludes the synthesis of full-length proteins. Furthermore, the resulting truncated proteins, if synthesized and stable, are likely to be non-functional or might even be deleterious to cellular metabolism. Approximately one third of genetic and acquired diseases are due to PTCs. In fact, PTCs are apt to cause at least some cases of all diseases that involve protein insufficiency. Cells have evolved a way to eliminate mRNAs that contain PTCs using a mechanism called nonsense-mediated mRNA decay (NMD). Here, we will review how to determine which PTCs elicit NMD, what is currently known about the mechanism of NMD, and additional information that is pertinent to establishing therapies for PTC-associated diseases.
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Affiliation(s)
- Holly A Kuzmiak
- Department of Biochemistry and Biophysics, School of Medicine and Dentistry, 601 Elmwood Avenue, Box 712, University of Rochester, Rochester, NY 14642, USA
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