• BMB Reports
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• v.51 no.7
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• pp.315-316
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• 2018

Genome engineering with clustered regularly interspaced short palindromic repeats (CRISPR) system can be used as a tool to correct pathological mutations or modulate gene expression levels associated with pathogenesis of human diseases. Owing to well-established local administration methods including intravitreal and subretinal injection, it is relatively easy to administer therapeutic genome engineering machinery to ocular tissues for treating retinal diseases. In this context, we have investigated the potential of in vivo genome engineering as a therapeutic approach in the form of ribonucleoprotein or CRISPR packaged in viral vectors. Major issues in therapeutic application of genome engineering include specificity and efficacy according to types of CRISPR system. In addition to previous platforms based on ribonucleoprotein and CRISPR-associated protein 9 derived from Campylobacter jejuni, we evaluated the therapeutic effects of a CRISPR RNA-guided endonuclease derived from Lachnospiraceae bacterium ND2006 (LbCpf1) in regulating pathological angiogenesis in an animal model of wet-type age-related macular degeneration. LbCpf1 targeting Vegfa or Hif1a effectively disrupted the expression of genes in ocular tissues, resulting in suppression of choroidal neovascularization. It was also notable that there were no significant off-target effects in vivo.

• Molecules and Cells
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• v.38 no.6
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• pp.475-481
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• 2015

Programmable nucleases, which include zinc-finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs), and RNA-guided engineered nucleases (RGENs) repurposed from the type II clustered, regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 9 (Cas9) system are now widely used for genome editing in higher eukaryotic cells and whole organisms, revolutionising almost every discipline in biological research, medicine, and biotechnology. All of these nucleases, however, induce off-target mutations at sites homologous in sequence with on-target sites, limiting their utility in many applications including gene or cell therapy. In this review, we compare methods for detecting nuclease off-target mutations. We also review methods for profiling genome-wide off-target effects and discuss how to reduce or avoid off-target mutations.

• Journal of Animal Reproduction and Biotechnology
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• v.34 no.2
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• pp.65-69
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• 2019

Since the development of the first genetically-modified mouse, transgenic animals have been utilized for a wide range of industrial applications as well as basic research. To date, these transgenic animals have been used in functional genomics studies, disease models, and therapeutic protein production. Recent advances in genome modification techniques such zinc finger nuclease (ZFN), transcription activator-like effector nucleases (TALEN), and clustered regularly interspaced short palindromic repeats (CRIPSR)-Cas9, have led to rapid advancement in the generation of genome-tailored livestock, as well as experimental animals; however, the development of genome-edited poultry has shown considerably slower progress compared to that seen in mammals. Here, we will focus primarily on the technical strategies for production of transgenic and gene-edited chickens, and their potential for future applications.

• BMB Reports
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• v.53 no.7
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• pp.341-348
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• 2020

The targeted nuclease clustered, regularly interspaced short palindromic repeats/CRISPR-associated proteins (CRISPR/Cas) system has recently emerged as a prominent gene manipulation method. Because of its ease in programming targeted DNA/protein binding through RNA in a vast range of organisms, this prokaryotic defense system is a versatile tool with many applications in the research field as well as high potential in agricultural and clinical improvements. This review will present a brief history that led to its discovery and adaptation. We also present some of its restrictions, and modifications that have been performed to overcome such restrictions, focusing specifically on the most common CRISPR/Cas9 mediated non-homologous end joint repair.

• Molecules and Cells
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• v.41 no.8
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• pp.717-723
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• 2018

Chimeric antigen receptor (CAR) T-cell therapy, an emerging immunotherapy, has demonstrated promising clinical results in hematological malignancies including B-cell malignancies. However, accessibility to this transformative medicine is highly limited due to the complex process of manufacturing, limited options for target antigens, and insufficient anti-tumor responses against solid tumors. Advances in gene-editing technologies, such as the development of Zinc Finger Nucleases (ZFNs), Transcription Activator-Like Effector Nucleases (TALENs), and Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR/Cas9), have provided novel engineering strategies to address these limitations. Development of next-generation CAR-T cells using gene-editing technologies would enhance the therapeutic potential of CAR-T cell treatment for both hematologic and solid tumors. Here we summarize the unmet medical needs of current CAR-T cell therapies and gene-editing strategies to resolve these challenges as well as safety concerns of gene-edited CAR-T therapies.

• Clinical and Experimental Pediatrics
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• v.64 no.6
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• pp.269-279
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• 2021

Clustered regularly interspaced short palindromic repeats and CRISPR-associated protein 9 (CRISPR-Cas9) is an ancient prokaryotic defense system that precisely cuts foreign genomic DNA under the control of a small number of guide RNAs. The CRISPR-Cas9 system facilitates efficient double-stranded DNA cleavage that has been recently adopted for genome editing to create or correct inherited genetic mutations causing disease. Congenital heart disease (CHD) is generally caused by genetic mutations such as base substitutions, deletions, and insertions, which result in diverse developmental defects and remains a leading cause of birth defects. Pediatric CHD patients exhibit a spectrum of cardiac abnormalities such as septal defects, valvular defects, and abnormal chamber development. CHD onset occurs during the prenatal period and often results in early lethality during childhood. Because CRISPR-Cas9-based genome editing technology has gained considerable attention for its potential to prevent and treat diseases, we will review the CRISPR-Cas9 system as a genome editing tool and focus on its therapeutic application for CHD.

• BMB Reports
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• v.52 no.8
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• pp.475-481
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• 2019

The evolution of genome editing technology based on CRISPR (clustered regularly interspaced short palindromic repeats) system has led to a paradigm shift in biological research. CRISPR/Cas9-guide RNA complexes enable rapid and efficient genome editing in mammalian cells. This system induces double-stranded DNA breaks (DSBs) at target sites and most DNA breakages induce mutations as small insertions or deletions (indels) by non-homologous end joining (NHEJ) repair pathway. However, for more precise correction as knock-in or replacement of DNA base pairs, using the homology-directed repair (HDR) pathway is essential. Until now, many trials have greatly enhanced knock-in or substitution efficiency by increasing HDR efficiency, or newly developed methods such as Base Editors (BEs). However, accuracy remains unsatisfactory. In this review, we summarize studies to overcome the limitations of HDR using the CRISPR system and discuss future direction.

• Journal of Animal Science and Technology
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• v.65 no.2
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• pp.473-477
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• 2023

Lactobacillus amylovorus CACC736 was originated from swine feces in Korea. The complete genome sequences of the strain contained one circular chromosome (2,057,809 base pair [bp]) with 38.2% guanine-cytosine (GC) content and two circular plasmids, namely, pCACC736-1 and pCACC736-2. The predicted protein-coding genes, which are encoding the clustered regularly interspaced short palindromic repeats (CRISPR)-associated proteins, biosynthesis of bacteriocin (helveticin J), and the related proteins of the bile, acid tolerance. Notably, the genes related to vitamin B-group biosynthesis (riboflavin and cobalamin) were also found in L. amylovorus CACC736. Collectively, the complete genome sequence of the L. amylovorus CACC736 will aid in the development of functional probiotics in the animal industry.

• Journal of Environmental Science International
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• v.32 no.3
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• pp.173-179
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• 2023

Rats are one of the most widely used animals in biomedical sciences because their metabolism and physiology are comparable to humans. In recent years, gene-targeted models have been developed using various animal species utilizing engineered nucleases such as clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated gene (Cas). It has recently become possible to efficiently transfect CRISPR/Cas into embryos via electroporation. However, electroporation can damage fertilized eggs; therefore, it is important to determine the optimal embryo culture conditions. A standardized approach for routine and reproducible rat transgenesis will render rat models more accessible for research. We performed experiments to obtain rat embryos with efficient superovulation and synchronization, and to investigate the appropriate medium conditions for pronuclear stage embryos subjected to electroporation stimulation for the introduction of engineered nuclease.

• Development and Reproduction
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• v.27 no.1
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• pp.1-7
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• 2023

Small-cell lung cancer (SCLC) continues to be the deadliest of all lung cancer types. Its high mortality is largely attributed to the unchangeable development of resistance to standard chemo/radiotherapies, which have remained invariable for the past 30 years, underlining the need for new therapeutic approaches. Recent studies of SCLC genome revealed a large number of somatic alterations and identified remarkable heterogeneity of the frequent mutations except for the loss of both RB and P53 tumor suppressor genes (TSGs). Identifying the somatic alterations scattered throughout the SCLC genome will help to define the underlying mechanism of the disease and pave the way for the discovery of therapeutic vulnerabilities associated with genomic alterations. The new technique made it possible to determine the underlying mechanism for the discovery of therapeutic targets. To these ends, the techniques have been focused on understanding the molecular determinants of SCLC.