敲除BMAL1基因促进HL-60细胞凋亡并抑制增殖

Knockout of BMAL1 Gene Induces Apoptosis of HL-60 Cells and Inhibits its Proliferation

目的:运用CRISPR/Cas9技术敲除节律基因BMAL1的HL-60细胞系,探讨BMAL1分子在人急性髓系白血病中的生物学功能。方法:针对BMAL1基因设计2条sg RNA,构建含有sg RNA的PX459敲除载体;应用T7核酸内切酶I检测设计的sg RNA活性;应用打靶载体瞬时转染HL-60细胞构建BMAL1敲除细胞系,应用Western blot检测BMAL1蛋白的表达,应用流式细胞仪检测敲除细胞系的凋亡水平,应用CCK-8试剂盒检测敲除细胞系的增殖能力。结果:成功构建了针对BMAL1的PX459-sg RNA载体;并筛选得到了活性较高的打靶载体。Western blot实验在敲除细胞中未检测到BMAL1蛋白的表达。进一步实验发现,BMAL1敲除的HL-60细胞凋亡水平明显升高,细胞增殖能力明显减弱。结论:利用CRISPR/Cas9技术成功构建了BMAL1基因敲除的HL-60细胞系,并发现BMAL1敲除可以促进HL-60细胞的凋亡,抑制肿瘤细胞的增殖,初步揭示了BMAL1生物节律基因在急性髓系白血病中的生物学作用。

Objective： To explore the biological function of BMAL1 in human acute myeloid leukemia by means of the HL-60 cell line in whica circadian gene BMAL1 was konocked-out by the CRISPR/Cas9 technology. Methods：Two sgRNAs for BMAL1 were designed and the PX459 knockout vectors containing the sgRNA were constructed. The activity of 2 sgRNAs was detected by T7 endonuclease I. the BMAL1 knocked out HL-60 cells were prepared by transient transfection of the target vectors into the cells. Western blot was used to detect the expression of BMAL1 protein. The apoptosis of the targeted cells was detected by flow cytometry. The proliferation status of the cells was assessed by the CCK-8 assay. Results： The PX459-sgRNA vectors were successfully constructed and screened to assure the activity of the targeting vector. It was found that the expression of BMAL1 protein was not detected in BMAL1-knocked out HL-60 cells. Further, it was shown that BMAL1 knockdout could promote the apoptosis of HL-60 cells and inhibit the cell proliferation ability. Conclusion： BMAL1 knocked out HL-60 cells have bean successfully established using the CRISPR/Cas9 gene editing technique, and BMAL1 knockout can promote the HL-60 cell apoptosis and inhibit its proliferation.These result reveal the biological role of the BMAL1 circadian gene in acute myeloid leukemia.