西班牙能源环境与技术研究中心Paula Río小组最新研究揭示，由CRISPR-Cas9诱导的DNA断裂的非同源末端连接修复能有效纠正范科尼贫血患者HSPCs的突变。 2019年9月19日，国际期刊《细胞—干细胞》在线发表了这一成果。

研究显示多个范科尼贫血（FA）互补组（包括FA-A，FA-C，FA-D1和FA-D2）的造血细胞中存在受损功能的可行性校正。非同源末端连接（NHEJ）介导的靶向CRISPR-Cas9诱导的DNA断裂的修复方式可以产生补偿性插入和缺失，其恢复突变基因的编码框。 NHEJ介导的编辑功效最初在FA淋巴母细胞系中得到验证，随后在原代FA患者衍生的CD34 ⁺细胞中得以验证，其在体外和移植后都显示出显著的增殖优势和表型校正。重要的是，与同源定向修复相反，NHEJ有效地靶向人造血干细胞（HSC）母细胞，表明NHEJ编辑方法可以作为编辑人体自我更新HSC的合理替代方案，并可用于治疗影响造血系统的FA和其他单基因疾病。

研究人员表示，非同源末端连接（NHEJ）是造血干细胞（HSC）用于修复双链DNA断裂的优选机制，并且在范科尼贫血（FA）途径缺陷的细胞中增加显著。

附：英文原文

Title: NHEJ-Mediated Repair of CRISPR-Cas9-Induced DNA Breaks Efficiently Corrects Mutations in HSPCs from Patients with Fanconi Anemia

Author: Francisco José Román-Rodríguez, Laura Ugalde, Lara álvarez, Begoa Díez, María José Ramírez, Cristina Risueo, Marta Cortón, Massimo Bogliolo, Sara Bernal, Francesca March, Carmen Ayuso, Helmut Hanenberg, Julián Sevilla, Sandra Rodríguez-Perales, Raúl Torres-Ruiz, Jordi Surrallés, Juan Antonio Bueren, Paula Río

Issue&Volume: 19 September 2019

Summary: 

Non-homologous end-joining (NHEJ) is the preferred mechanism used by hematopoietic stem cells (HSCs) to repair double-stranded DNA breaks and is particularly increased in cells deficient in the Fanconi anemia (FA) pathway. Here, we show feasible correction of compromised functional phenotypes in hematopoietic cells from multiple FA complementation groups, including FA-A, FA-C, FA-D1, and FA-D2. NHEJ-mediated repair of targeted CRISPR-Cas9-induced DNA breaks generated compensatory insertions and deletions that restore the coding frame of the mutated gene. NHEJ-mediated editing efficacy was initially verified in FA lymphoblastic cell lines and then in primary FA patient-derived CD34 + cells, which showed marked proliferative advantage and phenotypic correction both in vitro and after transplantation. Importantly, and in contrast to homologous directed repair, NHEJ efficiently targeted primitive human HSCs, indicating that NHEJ editing approaches may constitute a sound alternative for editing self-renewing human HSCs and consequently for treatment of FA and other monogenic diseases affecting the hematopoietic system.

DOI: 10.1016/j.stem.2019.08.016

Source: https://www.cell.com/cell-stem-cell/fulltext/S1934-5909(19)30351-0