Reduction of BCL11A in hematopoietic stem cells through gene editing:new strategy to ameliorate the severe β-globin disorders sickle cell disease

• 来源期刊: 科学通报（英文版）
• 年，卷（期）: 2019,（21）
• 页码范围: 1562-1564
• 页数: 3页
• 语种: 英文

摘要

Site-specific gene editing is of great importance in precise medicine.Two conventional genome editing methods,Zine finger nucleases (ZFNs) and transcription activator-like effector nucleases (TALENs),are based on protein-DNA recognition,with tedious work in constructing target protein [1,2].Developed from immune response of bacteria,CRISPR/Cas9 has been widely investigated as a promising tool for therapeutic genome editing in clinical settings nowadays [3,4].This system succeeds in gene deletion,insertion and frameshift mutations with higher efficiency,less cost,improved flexibility and simplified designing process [5].There are two crucial components in the CRISPR/Cas9 system:Cas9 endonuclease and single-stranded guide RNA (gRNA).A guide RNA (gRNA) is composed of a constant tracrRNA and a crRNA,forming base pairs with site-specific DNA sequences by the first changeable 20 nts in gRNA.After pairing,Cas9 "cut" the targeted DNA fragment and generate double stand break (DSB).Then,non-homologous end-joining (NHEJ) and homology directed repair (HDR) occur to repair DNA double stands with random base insertion or precise modification in presence of donor DNA templates [2].