• Asian Pacific Journal of Cancer Prevention
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• 제17권7호
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• pp.3329-3334
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• 2016

Cancer is thought to be a direct result of transcriptional misregulation. Broad analysis of transcriptional regulatory elements in healthy and cancer cells is needed to understand cancer development. Nucleases regulatory domains are recruited to bind and manipulate a specific genomic locus with high efficacy and specificity. TALENs (transcription activator-like effector nuclease) fused to endonuclease FokI have been used widely to target specific sequences to edit several genes in healthy and cancer cells. This approach is promising to target specific cancer genes and for this purpose it is needed to pack such TALENs into viral vectors. There are some considerations which control the success of this approach, targeting appropriate sequences with efficient construction of TALENs being crucial factors. We face some obstacles in construction of TALENs; in this study we made a modification to the method of Cermk et al 2011 and added one step to make it easier and increase the availability of constructs.

• Asian-Australasian Journal of Animal Sciences
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• 제29권3호
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• pp.413-418
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• 2016

Myostatin (MSTN) is a secreted growth factor expressed in skeletal muscle and adipose tissue that negatively regulates skeletal muscle mass. Gene knockout of MSTN can result in increasing muscle mass in sheep. The objectives were to investigate whether myostatin gene can be edited in sheep by transcription activator-like effector nucleases (TALENs) in tandem with single-stranded DNA oligonucleotides (ssODNs). We designed a pair of TALENs to target a highly conserved sequence in the coding region of the sheep MSTN gene. The activity of the TALENs was verified by using luciferase single-strand annealing reporter assay in HEK 293T cell line. Co-transfection of TALENs and ssODNs oligonucleotides induced precise gene editing of myostatin gene in sheep primary fibroblasts. MSTN gene-edited cells were successfully used as nuclear donors for generating cloned embryos. TALENs combined with ssDNA oligonucleotides provide a useful approach for precise gene modification in livestock animals.

• Molecules and Cells
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• 제39권9호
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• pp.687-691
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• 2016

Transcription activator-like effector nucleases (TALENs) are powerful tools for targeted genome editing in diverse cell types and organisms. However, the highly identical TALE repeat sequences make it challenging to assemble TALEs using conventional cloning approaches, and multiple repeats in one plasmid are easily catalyzed for homologous recombination in bacteria. Although the methods for TALE assembly are constantly improving, these methods are not convenient because of laborious assembly steps or large module libraries, limiting their broad utility. To overcome the barrier of multiple assembly steps, we report a one-step system for the convenient and flexible assembly of a 180 TALE module library. This study is the first demonstration to ligate 9 mono-/dimer modules and one circular TALEN backbone vector in a one step process, generating 9.5 to 18.5 repeat sequences with an overall assembly rate higher than 50%. This system makes TALEN assembly much simpler than the conventional cloning of two DNA fragments because this strategy combines digestion and ligation into one step using circular vectors and different modules to avoid gel extraction. Therefore, this system provides a convenient tool for the application of TALEN-mediated genome editing in scientific studies and clinical trials.

• Molecules and Cells
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• 제38권6호
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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.

• 월간양계
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• 제46권10호
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• pp.132-133
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• 2014

생식선 줄기세포 원천기술을 이용한 형질전환 조류 생산 시스템과 고효율의 유전자적 중 기술인 유전자가위법(TALEN)을 도입함으로써 기초연구 및 단기간내 새로운 가금품종 개발이 가능하게 되었다. 또한, 신약개발 및 치료물질 대량생산을 위한 형질전환가금품종 개발에 응용될 수도 있어 축산과 더불어 의약, 약학 등 매우 다양한 분야에서 가금의 활용 범위를 넓힐 수 있을것으로 기대된다. 개발된 기술은 계란성분 조절을 통한 기능성 식품 및 단백질-신약을 포함한 신물질 생산을 목적으로 하는 지식기반 생명산업의 획기적인 발전을 유도할 수 있다. 이에 유전자 가위 기법을 활용한 오브알부민 생산 유전자를 제거한 유전자 변형 닭 생산에 관한 주요내용을 소개코자 한다.

• Molecules and Cells
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• 제41권8호
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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.

• Asian-Australasian Journal of Animal Sciences
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• 제30권8호
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• pp.1175-1182
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• 2017

Objective: To create genetically modified goat as a biopharming source of recombinant human lacotoferrin (hLF) with transcription activator-like effector nucleases. Methods: TALENs and targeting vector were transferred into cultured fibroblasts to insert hLF cDNA in the goat beta-lactoglobulin (BLG) locus with homology-directed repair. The gene targeted efficiency was checked using sequencing and TE7I assay. The bi-allelic gene targeted colonies were isolated and confirmed with polymerase chain reaction, and used as donor cells for somatic cell nuclear transfer (SCNT). Results: The targeted efficiency for BLG gene was approximately 10%. Among 12 Bi-allelic gene targeted colonies, five were used in first round SCNT and 4 recipients (23%) were confirmed pregnant at 30 d. In second round SCNT, 7 (53%), 4 (31%), and 3 (23%) recipients were confirmed to be pregnant by ultrasound on 30 d, 60 d, and 90 d. Conclusion: This finding signifies the combined use of TALENs and SCNT can generate biallelic knock-in fibroblasts that can be cloned in a fetus. Therefore, it might lay the foundation for transgenic hLF goat generation and possible use of their mammary gland as a bioreactor for large-scale production of recombinant hLF.

• Journal of Plant Biotechnology
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• 제45권3호
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• pp.155-170
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• 2018

본 논문은 현재까지 개발된 유전자편집 기술들의 작용기작 및 장 단점 등을 비교하고 이들 기술로 개발된 유전자편집(site-directed mutagenesis, SDN)작물들의 안전성 평가를 위한 분류 기준 등을 살펴보았다. 또한 2016년부터 2018년 5월 현재까지 발표된 유전자편집 식물 개발과 관련된 논문들을 조사하여 ZFN, TALENS, CRISPR기술별 발표 논문 추세를 조사한 결과 CRISPR기술을 적용한 연구건수가 절대적으로 많았다. 또한 애기장대와 벼를 대상으로 수행한 연구건수가 가장 많았으며, 담배와 토마토, 밀, 옥수수 등이 그 뒤를 이었다. 하지만 발표건수는 아직 1~2건에 해당하지만 대상 식물들은 주곡작물을 포함하여 화훼, 채소, 과수 등으로 다양하게 그 응용 범위가 확대되고 있는 것으로 조사되었다. 특히 실용화 또는 향후 상업화를 목표로 한 연구건수도 해마다 증가하는 추세에 있으며 그 응용 범위도 유용단백질 또는 물질의 대량생산을 위한 대사공학 연구와 바이러스, 세균, 곰팡이 등에 대한 병저항성 작물의 개발, 가뭄 등의 무생물적 환경스트레스 저항성 작물, 수량이 증대된 작물 등의 개발에 집중되었다. 이 외에도 단위결실 토마토, 웅성불임성 이용 hybrid벼, 탈립 저항성 증진 등으로 응용 범위가 점점 다양화되어 가고 있음을 알 수 있었다. 또한 미국 농무성의 동 식물 검역소에서 허가를 득한 CRISPR유전자편집 작물의 건수도 해마다 증가하여 조만간 이들이 국제 종자시장에 출시될 것으로 전망된다.

• BMB Reports
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• 제45권12호
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• pp.686-692
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• 2012

Phenotypic analysis of gene-specific knockout (KO) mice has revolutionized our understanding of in vivo gene functions. As the use of mouse embryonic stem (ES) cells is inevitable for conventional gene targeting, the generation of knockout mice remains a very time-consuming and expensive process. To accelerate the large-scale production and phenotype analyses of KO mice, international efforts have organized global consortia such as the International Knockout Mouse Consortium (IKMC) and International Mouse Phenotype Consortium (IMPC), and they are persistently expanding the KO mouse catalogue that is publicly available for the researches studying specific genes of interests in vivo. However, new technologies, adopting zinc-finger nucleases (ZFNs) or Transcription Activator-Like Effector (TALE) Nucleases (TALENs) to edit the mouse genome, are now emerging as valuable and effective shortcuts alternative for the conventional gene targeting using ES cells. Here, we introduce the recent achievement of IKMC, and evaluate the significance of ZFN/TALEN technology in mouse genetics.

• BMB Reports
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• 제50권5호
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• pp.247-256
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• 2017

CRISPR/Cas9 is the latest tool introduced in the field of genome engineering and is so far the best genome-editing tool as compared to its precedents such as, meganucleases, zinc finger nucleases (ZFNs) and transcription activator-like effectors (TALENs). The simple design and assembly of the CRISPR/Cas9 system makes genome editing easy to perform as it uses small guide RNAs that correspond to their DNA targets for high efficiency editing. This has helped open the doors for multiplexible genome targeting in many species that were intractable using old genetic perturbation techniques. Currently, The CRISPR system is revolutionizing the way biological researches are conducted and paves a bright future not only in research but also in medicine and biotechnology. In this review, we evaluated the history, types and structure, the mechanism of action of CRISPR/Cas System. In particular, we focused on the application of this powerful tool in autophagy research.