细胞骨架在ns脉冲诱导肿瘤细胞凋亡中的作用

为了研究细胞骨架在ns脉冲诱导肿瘤细胞凋亡中的作用,将脉冲电场参数组合(电场强度10kV/cm,脉宽500ns,脉冲30个,频率1Hz)作用于细胞骨架裂解的Hep-G2细胞。利用Annexin-V和碘化丙碇(propidium i-odide,PI)双染法检测细胞凋亡和坏死情况;采用荧光分光光度计观测线粒体跨膜电位和细胞膜穿孔的变化情况。试验发现:肌动蛋白裂解后脉冲处理组的细胞凋亡和坏死大大降低(与单独脉冲处理组相比检验水平P<0.05),早期细胞凋亡由(16.94±2.87)%下降到(4.77±1.87)%;晚期凋亡和坏死由(20.94±3.09)%下降到(14.38±2.60)%;脉冲处理组和肌动蛋白裂解后脉冲处理组的细胞线粒体跨膜电位都出现下降,但后者的线粒体跨膜电位却明显高于前者(P<0.05);单独脉冲处理组和细胞骨架缺失后脉冲处理组二者在相同时间点时其PI荧光强度无明显差异,且PI荧光随时间而变化的规律亦相似。上述结果表明:细胞骨架的缺失抑制了ns脉冲诱导细胞凋亡的线粒体通路,进而降低细胞凋亡水平,但对细胞膜的穿孔情况无明显影响。

Effect of Cytoskeleton in Tumor Cell Apoptosis Induced by Nanosecond Pulsed Electric Field

In order to study the effect of cytoskeleton in tumor cell apoptosis induced by nanosecond pulsed electric field(nsPEF),Parameters(field intensity of 10 kV/cm,pulse duration of 500 ns,pulse number of 30,repetition frequency of 1 Hz) of nsPEF were performed on actin-disrupted Hep-G2 cells.Tumor cell apoptosis and necrosis were studied by Annexin-V and propidium iodide(PI),and change of the mitochondrial trans-membrane potential and cell electroporation course were also tested.Significant decreases in apoptosis and necrosis were observed in actin-disrupted nanosecond pulsed electric field(nsPEF) treated group by comparing to nsPEF treated only group(test level P<0.05),from(16.94±2.87)% to(4.77±1.87)% in early apoptosis,and(20.94±3.09)% to(14.38±2.60)% in late apoptosis and necrosis;meantime,decreases in mitochondrial trans-membrane potential were observed in both actin-disrupted nsPEF and nsPEF treated only groups,however,the latter was significantly higher than the former one(P<0.05);PI intensity at the same time and Changes in PI with time were similar in both nsPEF treated only and actin-disrupted nsPEF treated groups.The results indicated that,the loss of integrity of cytoskeleton can minimize the apoptosis induced by nsPEF through mitochondrial signaling pathway,and had no significant effect on plasma membrane electroporation.