Expression data from RUNX1S291fs-mutant and/or Ezh2 conditional knockout Lineage-c-Kit+Sca-1+ (LSK) cells. Mus musculus

Recent studies have showed that loss-of-function mutations of EZH2, a catalytic component of polycomb repressive complex 2, are often associated with RUNX1 mutations in myelodysplastic syndrome (MDS) patients. We established a novel MDS model mouse by transducing a RUNX1S291fs mutant in hematopoietic stem cells followed by deletion of Ezh2 and found that Ezh2 loss significantly promoted RUNX1S291fs-induced MDS. Overall design: We retrovirally transduced RUNX1S291fs or empty-control into either Cre-ERT;Ezh2wt/wt or Cre-ERT;Ezh2flox/flox (CD45.2+) HSCs. The transduced cells were transplanted into lethally irradiated recipient mice together with life-saving CD45.1+ wild-type bone marrow cells. After deletion of Ezh2, gene expression analysis were performed on pooled bone marrow LSK cells isolated from WT, Ezh2Δ/Δ, RUNX1S291fs, and RUNX1S291fs/Ezh2Δ/Δ mice (n=2-4) and two distinct RUNX1S291fs/Ezh2Δ/Δ-MDS mouse.

已有研究证实，作为多梳抑制复合物2（polycomb repressive complex 2）催化亚基的EZH2（EZH2）功能丧失性突变，常与骨髓增生异常综合征（myelodysplastic syndrome, MDS）患者的RUNX1突变相关。本研究通过在造血干细胞中转导RUNX1S291fs突变体并后续敲除Ezh2，构建了新型骨髓增生异常综合征小鼠模型，且发现Ezh2缺失可显著促进RUNX1S291fs诱导的骨髓增生异常综合征。整体实验设计：我们将RUNX1S291fs或空载体对照通过逆转录病毒转导至Cre-ERT;Ezh2wt/wt或Cre-ERT;Ezh2flox/flox（CD45.2+）造血干细胞（hematopoietic stem cells, HSCs）中。将转导后的细胞与挽救性CD45.1+野生型骨髓细胞共同移植至经致死剂量辐照的受体小鼠体内。在Ezh2缺失后，我们对从野生型（WT）、Ezh2纯合缺失（Ezh2Δ/Δ）、RUNX1S291fs单突变及RUNX1S291fs/Ezh2Δ/Δ双突变小鼠（n=2-4），以及2只独立的RUNX1S291fs/Ezh2Δ/Δ-MDS模型小鼠中分离的混合骨髓LSK细胞开展了基因表达分析。