Abstract: The aim of the study is to uncover the mechanism of reduced proliferation of K562 cells resulting from LSD1 depletion. Making use of the LSD1-/- K562 cell lines, cellular apoptosis was measured by Annexin V/PI double staining with flow cytometry. Cell cycle was examined using PI staining with flow cytometry. We want to explore whether the apoptosis level of K562 cells is altered and whether cell cycle is affected after knockout of LSD1 gene. The results showed that there was no induction of apoptosis in K562 cells after LSD1 depletion; the cell cycle of K562 cells arrested at the G0/G1 phase, cells decline in the DNA duplication phase. The results indicated that LSD1 depletion inhibits K562 cells proliferation mainly via impairment of cell cycle but not apoptosis.

Key words: K562 cells, LSD1 gene, apoptosis, cell cycle

摘要： 为了探讨敲除LSD1基因后抑制人慢性髓系白血病 K562细胞增殖的原因，使用前期CRISPR/Cas9技术构建的人慢性髓系白血病 K562 LSD1基因敲除株，通过细胞凋亡Annexin V/PI（碘化丙啶）双染色、细胞PI染色以及流式细胞术技术，探究敲除LSD1基因后，K562细胞的凋亡水平是否改变，细胞周期是否受到影响。结果表明敲除LSD1基因后K562细胞被阻滞在G0/G1期，进入DNA复制期的细胞变少，因此导致细胞增殖速度减慢；通过细胞凋亡Annexin V/PI双染色并分析早期以及晚期凋亡细胞总比例，显示敲除LSD1基因后，不影响K562细胞的凋亡。研究结果表明，敲除LSD1基因后人慢性髓系白血病 K562细胞的增殖受到抑制，这是由于K562细胞增殖周期发生了改变，进入DNA复制期和分裂期的细胞减少；而与细胞凋亡水平的变化无关。

关键词: 人慢性髓系白血病K562细胞, LSD1基因, 细胞凋亡, 细胞周期