RUNXOR长链非编码RNA在t(8;21)染色体转位中的作用及机制

Acute myelogenous leukemia (AML) is the most common hematopoietic malignancy that primarily affects adults. The RUNX1 gene, also known as AML1, is a Runt-related transcription factor that regulates critical processes in hematopoiesis and defines the definitive hematopoietic stem cells. Located on chromosomal 21, the RUNX1 gene is involved in multiple chromosomal translocations in leukemia. Among them, t(8,21) is one of the most common chromosomal translocations found in acute myeloid leukemia (AML), forming the RUNX1-ETO fusion protein invovled in the development of leukemia. However, the specific molecular mechanism underlying this chromosomal translocation in AML is poorly defined...Using R3C (RNA-guided Chromatin Conformation Capture), we have recently identified a novel long non-coding RNA (lncRNA), called RUNXOR,in the RUNX1 gene locus. RUNXOR is transcribed from a upstream promoter and overlapps with RUNX1. Most importantly, this lncRNA is a nuclear lncRNA that binds to mutiple RUNX1-related translocation breakpoints, including ETO in chromosome 8, EVI1 in chromosome 3 and RUNX1 in chromosome 21. Togethere, these data suggest that this nuclear lncRNA may directly participate in the RUNX1-related translocation in AML. ..In this project, we propose to use a novel CRISPR/Cas9 gene editing technology to explore the role of RUNXOR lncRNA in t(8;21) translocation. We will use this CRISPR/Cas9 system to induce t(8;21) translocation in KG-1 lekemia cell line. We will examine if the induced t(8;21) translocation will be interupted by RUNXOR lncRNA knockdown. Using epigenetic technologies available in the lab, including R3C,RAT, we will examine the mechanisms by which RUNXOR lncRNA epigenetically enhances the RUNX-ETO fusion. Finally, we will exmine if this CRISPR/Cas9-induce t(8;21) translocation will affect the self-renewal and malignancies of lekemia stem cells. This study may shed light on a novel therapeutic strategy to treat leukemia by harnessing an epigenetic mechanism.

RUNX1是急性髓系白血病（AML）转位突变最易累及的基因之一，t（8;21）转位后产生的RUNX1-ETO融合蛋白直接参与肿瘤的发生，但转位机制不清。我们课题组前期研究发现一条由RUNX1上游启动子转录，并与RUNX1基因重叠的全新长链非编码RNA (RUNXOR)，并证实该非编码RNA同时与21号染色体RUNX1和8号染色体的ETO基因的转位高发位点序列相结合，改变染色质空间构象，提示RUNXOR在白血病转位中起着重要作用。本课题拟采用最新报道的CRISPR/Cas9 基因靶向编辑技术，对RUNXOR介导t（8,21）染色体转位及分子机制进行深入研究，为临床治疗及新药研究开发提供新的理论依据。

RUNX1是急性髓系白血病（AML）转位突变最易累及的基因之一，t（8;21）转位后产生的RUNX1-ETO融合蛋白直接参与肿瘤的发生，但转位机制不清。课题组前期研究发现一条由RUNX1上游启动子转录，并与RUNX1基因重叠的全新长链非编码RNA (RUNXOR)，并证实该非编码RNA同时与21号染色体RUNX1和8号染色体的ETO基因的转位高发位点序列相结合，改变染色质空间构象，提示RUNXOR在白血病转位中起着重要作用。本课题采用最新报道的CRISPR/Cas9 基因靶向编辑技术，对RUNXOR介导t（8,21）染色体转位及分子机制进行深入研究，以期为临床治疗及新药研究开发提供新的理论依据。