20(S)-人参皂苷Rg3对乳腺癌MCF-7细胞的诱导凋亡作用

目的：探讨20(S)-人参皂苷Rg3(SPG-Rg3)对人乳腺癌MCF-7细胞的诱导凋亡作用及其可能机制。方法：人乳腺癌细胞MCF-7细胞株分为SPG-Rg3实验组及空白对照组。采用MTT法观察SPG-Rg3对MCF-7细胞生长的抑制作用，并计算出IC₅₀，依据IC₅₀值确定SPG-Rg3的有效浓度；流式细胞术检测SPG-Rg3作用后MCF-7细胞周期的变化；AO/EB双染从形态学上观察SPG-Rg3对MCF-7细胞凋亡的作用；免疫细胞化学染色和RT-PCR技术分别从蛋白水平和分子水平上检测SPG-Rg3对MCF-7细胞的诱导凋亡作用及其与caspase-8基因的关系。结果：SPG-Rg3 IC₅₀为（155.70±0.71） mg?L^-1，当SPG-Rg3浓度在37.5~600.0ｍg?L^-1时，MCF-7细胞的生长抑制率随SPG-Rg3浓度的增加而增大，与对照组比较，细胞增殖受到明显抑制（P<0.05）；MCF-7细胞的生长周期也发生变化，S期细胞数增加,明显高于对照组（P<0.01)，G₂/M期细胞数则明显少于对照组（P<0.01)；并且在G₁峰前出现明显的凋亡峰，凋亡细胞数增加。形态学上观察到SPG-Rg3（150 mg?L^-1）实验组细胞大部分核着黄色荧光或橘红色荧光，形态呈固缩状、圆珠状或新月形，呈现明显的凋亡改变；caspase-8免疫细胞化学染色可见，对照组MCF-7细胞caspase-8蛋白不表达，SPG-Rg3实验组则呈强表达，两组细胞HSCORE得分为1.894±0.027及2.869±0.043，两组比较差异有显著性（P<0.01）；提取细胞mRNA并设计caspase-8引物进行RT-PCR，SPG-Rg3实验组细胞caspase-8大量表达，对照组细胞无表达。结论：SPG-Rg3能诱导乳腺癌MCF-7细胞发生凋亡，其机制可能与其活化caspase-8作用有关。

MCF-7 cell apoptosis induced by 20(S)-ginsendoside Rg3 in mammary carcinoma

Objective To study the effect of 20(S)-ginsendoside Rg3(SPG-Rg3) on apoptosis of human mammary carcinoma line MCF-7 cells and its possible mechanism. Methods Human mammary carcinoma line MCF-7 cells were divided into experiment group of SPG-Rg3 and control group. The inhibition of SPG-Rg3 on the growth of MCF-7 cells was detected by MTT assay,IC50 was calculated to obtain the effective concentration; flow cytometry was used to observe the cell cycle of MCF-7 cells; AO/EB fluorescence double-dye technology w...