Rac1表达调控对髓母细胞瘤Daoy细胞增殖与凋亡的影响

目的 探讨Rac1基因沉默对髓母细胞瘤Daoy细胞株细胞周期、凋亡的影响.方法 将Daoy细胞分为2组:Rac1-shRNA组和对照组,Rac1-shRNA组将Rac1-shRNA质粒转染Daoy细胞,对照组则转染空白质粒.分别用RT-PCR、Western blot及流式细胞仪检测2组Daoy细胞Rac1 mRNA、Rac1蛋白、细胞周期、细胞凋亡率的变化,并进行统计学比较.结果 Rac1 mRNA和Racl蛋白在髓母细胞瘤Daoy细胞株中均有高表达;Rac1基因沉默后Daoy细胞细胞周期受阻于G0～G1期,G0～G1期细胞所占比例明显增加(80.9%±4.9%),而S期所占细胞比例减少(11.8%±2.3%);Rac1-shRNA组Daoy细胞凋亡率为36.7%±3.9%,而对照组为8.5%±0.9%.2组比较差异均有统计学意义(P<0.05).结论 RNA干扰沉默Rac1基因可以抑制Daoy细胞增殖,促进细胞凋亡,Rac1可成为抑制髓母细胞瘤增殖并促进细胞凋亡新的靶点.

Regulation of Rac1 expression affecting cell proliferation and apoptosis of Daoy cells in medulloblastoma

Objective To investigate the effects of Rac1 gene silencing on cell cycle and apoptosis of Daoy cell line in medulloblastoma. Methods Daoy cells were divided into Rac1-shRNA group and empty plasmid control group; Daoy cells in the former group were transfected by using Rac1-shRNA plasmid (Rac1-shRNA). RT-PCR, Western blotting and flow cytometry were used to observe the changes of cycle and apoptosis of Daoy cells after Rac1 gene silencing. Results Rac1 mRNA and protein in medulloblastoma Daoy cell lines were highly expressed; cell cycle of Daoy cells with Rac1 gene silencing were blocked at G0-G1 phases and cell percentage of G0-G1 phases significantly increased to 80.9%±4.9%; however, the proportion of cells in the S phase reduced to 11.8%± 2.3%. The apoptosis rate of Rac1-shRNA plasmid group (36.7%±3.9%) was significantly different as compared with that of empty plasmid control group (8.5% ±0.9%) (P<0.05). Conclusion RNA-interfered Rac1 gene silencing can inhibit the proliferation of Daoy cells and promote their apoptosis, indicating that Rac1 may become a new target being able to inhibit the cell proliferation and promote the apoptosis of Daoy cells in medulloblastoma.