慢性粒细胞白血病（CML）的临床治疗面临酪氨酸激酶抑制剂（TKIs）耐药、白血病干细胞（LSC）对TKIs不敏感，残留LSC致疾病复发等难题，亟需探索根治CML的方法。bcr-abl融合基因是CML的发病根源，也是耐药、复发的根源，因此，探寻能够清除bcr-abl融合基因的方法将有可能从根本上解决临床耐药、复发问题。本项目拟利用突变修饰的CRISPR/dCas9系统引导的Fok I核酸酶定点修饰靶基因的原理，构建高效、特异结合bcr-abl基因的CRISPR/dCas9-Fok I核酸酶，促发bcr-abl DNA双链断裂，启动细胞自身的同源定向修复（HDR）和非同源末端连接（NHEJ）修复机制，人工诱导bcr-abl基因移码突变，达到彻底破坏bcr-abl基因组，清除CML的致病源动力，解决耐药和复发难题的目的。本项目有望为CML患者，尤其是TKIs疗效差和复发的患者提供一种替代疗法。

In the clinical treatment of chronic myeloid leukemia，resistance to tyrosine kinase inhibitors (TKIs) and recurrence caused by leukemia stem cells (LSC) which are insensitive to TKIs are the key defects which need further solutions. The bcr-abl fusion gene is not only the primary pathogenesis of CML, but also the origin of resistance and recurrence. Therefore, a method eliminating the bcr-abl fusion gene will fundamentally solve the clinical TKIs resistance and recurrence problem. In this project, we plan to design a mutation modified CRISPR/dCas9 system guided Fok I nuclease aiming to combine with bcr-abl with high efficiency and specificity which will lead to a DNA double stranded break in bcr-abl target sequence and start cellular DNA repair procedure comprised of homology directed repair (HDR) and non homologous end joining (NHEJ), which then induce bcr-abl gene frame shift mutation, resulting in disruption of bcr-abl locus and resultant elimination of the pathogenic origin of CML. This project is expected to solve the clinical TKIs resistance and recurrence problem, and provide an alternative therapy for CML patients, especially for the ones response poorly to TKIs and recurrent.