PDF(Pubmed)
Abstract：
Nuclease-based genome editing strategies hold great promise for the treatment of blood disorders. However, a major drawback of these approaches is the generation of potentially harmful double strand breaks (DSBs). Base editing is a CRISPR-Cas9-based genome editing technology that allows the introduction of point mutations in the DNA without generating DSBs. Two major classes of base editors have been developed: cytidine base editors or CBEs allowing C>T conversions and adenine base editors or ABEs allowing A>G conversions. The scope of base editing tools has been extensively broadened, allowing higher efficiency, specificity, accessibility to previously inaccessible genetic loci and multiplexing, while maintaining a low rate of Insertions and Deletions (InDels). Base editing is a promising therapeutic strategy for genetic diseases caused by point mutations, such as many blood disorders and might be more effective than approaches based on homology-directed repair, which is moderately efficient in hematopoietic stem cells, the target cell population of many gene therapy approaches. In this review, we describe the development and evolution of the base editing system and its potential to correct blood disorders. We also discuss challenges of base editing approaches-including the delivery of base editors and the off-target events-and the advantages and disadvantages of base editing compared to classical genome editing strategies. Finally, we summarize the recent technologies that have further expanded the potential to correct genetic mutations, such as the novel base editing system allowing base transversions and the more versatile prime editing strategy.
摘要：
基于核酸酶的基因组编辑策略为血液疾病的治疗带来了巨大的希望。然而,这些方法的主要缺点是产生潜在有害的双链断裂(DSB)。碱基编辑是一种基于CRISPR-Cas9的基因组编辑技术，允许在DNA中引入点突变而不产生DSB。已经开发了两大类碱基编辑器:允许C>T转化的胞苷碱基编辑器或CBE和允许A>G转化的腺嘌呤碱基编辑器或ABE。基本编辑工具的范围已广泛扩大，允许更高的效率，特异性，对以前无法接近的遗传基因座和多路复用的可及性，同时保持较低的插入和删除率(InDels)。碱基编辑是由点突变引起的遗传疾病的一种有前途的治疗策略，例如许多血液疾病，可能比基于同源定向修复的方法更有效，在造血干细胞中中等效率，许多基因治疗方法的靶细胞群。在这次审查中,我们描述了基础编辑系统的发展和演变及其纠正血液疾病的潜力。我们还讨论了碱基编辑方法的挑战-包括碱基编辑器的交付和脱靶事件-以及与经典基因组编辑策略相比的碱基编辑的优缺点。最后,我们总结了最近的技术，这些技术进一步扩大了纠正基因突变的潜力，例如新颖的基础编辑系统允许基础转换和更多功能的主要编辑策略。
