为进一步研究ns级陡脉冲诱导细胞的凋亡效应,以人卵巢腺癌SKOV3细胞为对象,进行了电场强度为10kV/cm、脉宽为100ns的陡脉冲实验研究。结果表明,通过流式细胞术观测发现早期凋亡率约22%;通过AO/EB荧光染色检测显示,早期凋亡细胞表现为细胞体积缩小,胞膜完整,浓聚成颗粒状,位于细胞的一侧,胞质浓缩,呈黄绿色荧光;晚期凋亡细胞体积缩小,胞膜完整,细胞核呈橙红色或红色荧光;细胞坏死时,细胞体积增大,呈不均匀的橙红色荧光,轮廓不清,已解体或接近解体。医学统计学和形态学特征表明ns级陡脉冲能诱导SKOV3肿瘤细胞发生凋亡。
Recent research shows that nanosecond pulsed electric field can induce intracellular electromanipulation (IEM). However, apoptosis of cells was seldom observed, therefore, it is necessary validated further that nanosecond pulsed electric field can cause apoptosis of tumor cells, so as to provide credible experimental basis for tumor treatment with nanosecond pulsed electric field. In this paper, we studied the apoptosis of human's ovarian adenocarcinoma SKOV3 cells induced by nanosecond steep pulse using the steep pulse device made by ourselves. The apoptosis was determined by flow cytometry (FCM) after cells were exposed to nanosecond steep pulse with ten kilovolts per centimeter amplitude and one hundred nanoseconds pulse width. The result showed a significant number of early apoptotic cells (about 22%) for treated group, while the early apoptotic cells is about 3% for control group. The treated cells were also stained with AO/EB and observed under light microscope, and we can see four cell morphologic characters. The normal cell is elliptical regttlarly with intact cell membrane; its nucleolus fluoresces strong uniform green, and its cytoplasm fluoresces a little red under the green background. The early apoptotic cell became small; its cell membrane kept intact; its nucleolus fluoresced olivine or bisque, condensed into granule and was located in one side of the cell, and its cytoplasm fluoresced olivine. The terminal apoptotic cell became smaller; its cell membrane still kept intact; its nucleolus fluoresced salmon pink; and its cytoplasm also condensed and deflected, fluoresced red. The necrotic cell was swollen and fluoresces asymmetrical salmon pink, and its cell membrane with blurred profile might be ruptured or approached rupture. Combined statistics with morphologic characters, the experiment results show that nanosecond steep pulse can induce apoptosis of SKOV3 tumor ceils.