This paper aims to study the effects of traditional Chinese medicine Euphorbia esula on multidrug resistant human gastric cancer cells in the cell proliferation, migration, invasion and apoptosis, and to study the apoptosis-inducing pathway. Different dilutions of Euphorbia esula extract were used to process human multidrug resistant gastric cancer SGC7901/ADR cells. Cell proliferation inhibition phenomenon was determined by MTT experiment. Nuclear morphological changes of apoptotic cells and apoptotic indexes were observed and determined by Hochest33528 staining followed with fluorescence microscope observing. Flow cytometry was used to detect cell apoptosis rate. Cell migration and invasion ability were observed and determined by Transwell method. Spectrophotometry was used to detect caspase-3 and caspase-9 enzyme activity. Western blotting was used to detect subcellular distribution of cytochrome c. The results showed that Euphorbia esula extract had obvious inhibition effect on proliferation of gastric cancer multidrug resistant SGC7901/ADR cells, which was time- and concentration-dependent. After processing multidrug resistant gastric cancer SGC7901/ADR cells with Euphorbia esula extract, the apoptotic index and apoptosis rate were significantly increased than those in the control group, which showed a time- and dose-dependent mode; but if a caspase inhibitor was added, apoptosis index was not obviously increased. Transwell method showed that migration and invasion ability of the Euphorbia esula extract-processed SGC7901/ADR cells dropped significantly. Spectrophotometry showed that in Euphorbia esula extract-processed SGC7901/ADR cells, caspase-3 and caspase-9 expression were increased, which had significant differences with the control group. Western blotting test showed that the distribution of cytochrome c decreased in mitochondria, while increased in the cytoplasm (i.e., cytochrome c escaped from mitochondria to the cytoplasm). In conclusion, Euphorbia esula extract could inhibit the proliferation, migration and invasion, and induce apoptosis in human gastric cancer multidrug resistant SGC7901/ADR cells; and cytochrome c, caspase-9 and caspase-3 might be involved in cell apoptosis induced by Euphorbia esula extract, suggesting endogenous or mitochondrial apoptotic pathway.
本文旨在研究中药乳浆大戟抑制多药耐药人胃癌细胞增殖、迁移、侵袭的作用，以及诱导细胞凋亡的作用及其作用通路。用不同浓度的乳浆大戟提取液处理人胃癌多药耐药 SGC7901/ADR 细胞，MTT 试验观察细胞增殖抑制情况，Hochest33528 染色荧光显微镜观察凋亡细胞核形态并测定凋亡指数，流式细胞术测定细胞凋亡率，Transwell 法检测细胞迁移能力和侵袭能力，分光光度法检测 caspase-3 和 caspase-9 的酶活性表达，Western blotting 检测细胞色素 c 的亚细胞分布。结果发现，乳浆大戟提取液对人胃癌多药耐药 SGC7901/ADR 细胞有明显的增殖抑制作用，该作用具有时间和浓度依赖性。乳浆大戟提取液处理的人胃癌多药耐药 SGC7901/ADR 细胞，凋亡指数和凋亡率均比对照组显著升高，并有时间和剂量依赖性；但添加了 caspase 酶抑制剂的细胞，凋亡指数没有明显上升。Transwell 法检测显示，乳浆大戟提取液处理后的 SGC7901/ADR 细胞，迁移能力和侵袭能力显著下降。分光光度法检测发现，乳浆大戟提取液处理后的 SGC7901/ADR 细胞中，caspase-3 和 caspase-9 表达均增加，与对照组有明显差异。Western blotting 检测显示，细胞色素 c 在线粒体中的分布下降，在细胞质中的分布上升（即细胞色素 c 从线粒体向细胞质逸出）。研究表明，乳浆大戟提取液具有抑制人胃癌多药耐药 SGC7901/ADR 细胞增殖、抑制细胞迁移侵袭和诱导细胞凋亡的作用；乳浆大戟提取液诱导细胞凋亡的作用有细胞色素 c、caspase-9 和 caspase-3 的参与，提示内源性或线粒体凋亡通路。.
Keywords: Euphorbia esula; cell apoptosis; cell invasion; cell migration; cell proliferation; gastric cancer; multidrug resistance.