Biocev, 1st Medical Faculty, Charles University, 25250 Vestec, Czech Republic.
Department of Medicine III, University Hospital, LMU Munich, D-80539 Munich, Germany.
Int J Mol Sci. 2020 Mar 18;21(6):2073. doi: 10.3390/ijms21062073.
ISWI chromatin remodeling ATPase SMARCA5 (SNF2H) is a well-known factor for its role in regulation of DNA access via nucleosome sliding and assembly. SMARCA5 transcriptionally inhibits the myeloid master regulator PU.1. Upregulation of SMARCA5 was previously observed in CD34+ hematopoietic progenitors of acute myeloid leukemia (AML) patients. Since high levels of SMARCA5 are necessary for intensive cell proliferation and cell cycle progression of developing hematopoietic stem and progenitor cells in mice, we reasoned that removal of SMARCA5 enzymatic activity could affect the cycling or undifferentiated state of leukemic progenitor-like clones. Indeed, we observed that CRISPR/cas9-mediated knockout in AML cell lines (S5KO) inhibited the cell cycle progression. We also observed that the deletion induced karyorrhexis and nuclear budding as well as increased the ploidy, indicating its role in mitotic division of AML cells. The cytogenetic analysis of S5KO cells revealed the premature chromatid separation. We conclude that deleting SMARCA5 in AML blocks leukemic proliferation and chromatid cohesion.
ISWI 染色质重塑 ATP 酶 SMARCA5（SNF2H）是众所周知的核小体重塑因子，可通过核小体滑动和组装来调节 DNA 的可及性。SMARCA5 转录抑制髓系主调控因子 PU.1。先前在急性髓系白血病（AML）患者的 CD34+造血祖细胞中观察到 SMARCA5 的上调。由于高水平的 SMARCA5对于小鼠发育中的造血干/祖细胞的密集细胞增殖和细胞周期进展是必需的，因此我们推断去除 SMARCA5 的酶活性可能会影响白血病祖细胞样克隆的循环或未分化状态。事实上，我们观察到 CRISPR/cas9 介导的 AML 细胞系（S5KO）中的 敲除抑制了细胞周期进程。我们还观察到 缺失诱导核碎裂和核芽生，以及增加了倍性，表明其在 AML 细胞有丝分裂中的作用。S5KO 细胞的细胞遗传学分析显示出过早的染色单体分离。我们得出结论，在 AML 中删除 SMARCA5 可阻断白血病增殖和染色单体凝聚。
