Annotation and evaluation of base editing outcomes in multiple cell types using CRISPRbase

作者：Fan, Jibiao; Shi, Leisheng; Liu, Qi; Zhu, Zhipeng; Wang, Fan; Song, Runxian; Su, Jimeng; Zhou, Degui; Chen, Xiao; Li, Kailong; Xue, Lixiang^*; Sun, Lichao^*; Mao, Fengbiao^*

来源：Nucleic Acids Research, 2023, 51(D1): D1249-D1256.

DOI：10.1093/nar/gkac967

• TARGET BASE
• MUTATIONS
• PLATFORM
• DATABASE
• RICE
• DNA

CRISPR-Cas base editing (BE) system is a powerful tool to expand the scope and efficiency of genome editing with single-nucleotide resolution. The editing efficiency, product purity, and off-target effect differ among various BE systems. Herein, we developed CRISPRbase (http://crisprbase.maolab.org), by integrating 1 252 935 records of base editing outcomes in more than 50 cell types from 17 species. CRISPRbase helps to evaluate the putative editing precision of different BE systems by integrating multiple annotations, functional predictions and a blasting system for single-guide RNA sequences. We systematically assessed the editing window, editing efficiency and product purity of various BE systems. Intensive efforts were focused on increasing the editing efficiency and product purity of base editors since the byproduct could be detrimental in certain applications. Remarkably, more than half of cancer-related off-target mutations were non-synonymous and extremely damaging to protein functions in most common tumor types. Luckily, most of these cancer-related mutations were passenger mutations (4840/5703, 84.87%) rather than cancer driver mutations (863/5703, 15.13%), indicating a weak effect of off-target mutations on carcinogenesis. In summary, CRISPRbase is a powerful and convenient tool to study the outcomes of different base editors and help researchers choose appropriate BE designs for functional studies.

• 单位
  中国医学科学院; 广东省农业科学院; 河北医科大学; 山东大学; 东北林业大学; 中国医学科学院北京协和医院; 北京大学