Zheng Nannan, Li Liyang, Wang Xiangdong
Zhongshan Hospital Institute for Clinical Science, Shanghai Institute of Clinical Bioinformatics, Shanghai Engineering Research for AI Technology for Cardiopulmonary Diseases, Fudan University, Shanghai, China.
Clin Transl Med. 2020 Jan;10(1):412-426. doi: 10.1002/ctm2.34.
Methodologies of genome editing are rapidly developing with the improvement of gene science and technology, mechanism-based understanding, and urgent needs. In addition to the specificity and efficiency of on-target sites, one of the most important issues is to find and avoid off-targets before clinical application of gene editing as a therapy. Various algorithms, modified nucleases, and delivery vectors are developed to localize and minimize off-target sites. The present review aimed to clarify off-targets of various genome editing and explore potentials of clinical application by understanding structures, mechanisms, clinical applications, and off-target activities of genome editing systems, including CRISPR/Cas9, CRISPR/Cas12a, zinc finger nucleases, transcription activator-like effector nucleases, meganucleases, and recent developments. Current genome editing in cancer therapy mainly targeted immune systems in tumor microenvironment by ex vivo modification of the immune cells in phases I/II of clinical trials. We believe that genome editing will be the critical part of clinical precision medicine strategy and multidisciplinary therapy strategy by integrating gene sequencing, clinical transomics, and single cell biomedicine. There is an urgent need to develop on/off-target-specific biomarkers to monitor the efficacy and side-effects of gene therapy. Thus, the genome editing will be an alternative of clinical therapies for cancer with the rapid development of methodology and an important part of clinical precision medicine strategy.
随着基因科学技术的进步、基于机制的理解以及迫切需求，基因组编辑方法正在迅速发展。除了靶向位点的特异性和效率外，最重要的问题之一是在基因编辑作为一种治疗方法临床应用之前找到并避免脱靶效应。人们开发了各种算法、修饰的核酸酶和递送载体来定位并尽量减少脱靶位点。本综述旨在通过了解基因组编辑系统（包括CRISPR/Cas9、CRISPR/Cas12a、锌指核酸酶、转录激活样效应物核酸酶、巨型核酸酶）的结构、机制、临床应用和脱靶活性以及最新进展，阐明各种基因组编辑的脱靶效应，并探索其临床应用潜力。目前癌症治疗中的基因组编辑主要通过在临床试验的I/II期对免疫细胞进行体外修饰来靶向肿瘤微环境中的免疫系统。我们相信，通过整合基因测序、临床转录组学和单细胞生物医学，基因组编辑将成为临床精准医学策略和多学科治疗策略的关键部分。迫切需要开发靶向/脱靶特异性生物标志物来监测基因治疗的疗效和副作用。因此，随着方法学的快速发展，基因组编辑将成为癌症临床治疗的一种选择，也是临床精准医学策略的重要组成部分。
