七叶皂苷钠通过抑制AKT,ERK上游信号SRC活性诱导人乳腺癌MCF-7细胞凋亡

探讨七叶皂苷钠对乳腺癌MCF-7细胞的凋亡诱导作用及其可能的作用机制。运用MTT法检测七叶皂苷钠对MCF-7细胞的增殖抑制作用;倒置显微镜观察细胞形态学变化;DAPI染色后在荧光显微镜下检测细胞核变化;采用Annexin V-FITC/PI流式细胞术检测细胞凋亡率;采用Western blotting检测凋亡相关蛋白(PARP,cleaved caspase-8,pro-caspase-3)和细胞存活相关信号分子(AKT,ERK)及其共同上游激酶SRC的磷酸化变化情况。结果显示,不同浓度七叶皂苷钠作用于乳腺癌MCF-7细胞后,以剂量依赖方式抑制MCF-7细胞增殖;诱导细胞凋亡(典型的凋亡形态学变化、细胞核改变和细胞凋亡率显著增加);细胞凋亡相关蛋白PARP切割增加,cleaved caspase-8表达增加,pro-caspase-3表达减少进一步验证了七叶皂苷钠的凋亡诱导作用;七叶皂苷钠显著抑制细胞存活相关信号分子(AKT,ERK)的磷酸化,其共同上游激酶SRC的活化亦显著下降。结果表明,七叶皂苷钠通过抑制SRC的活化,阻断信号向下游信号分子AKT,ERK的传递,抑制乳腺癌细胞MCF-7增殖,诱导细胞凋亡。

Effect of sodium aescinate in inducing human breast cancer MCF-7 cells apoptosis by inhibiting AKT, ERK and upstream signal SRC activity

To study the effect of sodium aescinate in inducing human breast cancer MCF-7 cells apoptosis and its possible mechanism. MTT assay was used to detect the inhibitory effect of sodium aescinate on the proliferation of MCF-7 cells. The morphological changes were observed under inverted microscope. DAPI nuclear staining was used to detect the changes in cell nucleus. Annexin V-FITC/PI flow cytometry was adopted to test the apoptosis rate. Changes in apoptosis-related proteins (PARP, cleaved caspase-8 and pro-caspase-3), cell survival-associated signal molecules (AKT and ERK) and their common upstream kinase SRC was detected by Western blotting. The result showed that after different concentrations of sodium aescinate were used to treat breast cancer MCF-7 cells, they inhibited the proliferation of MCF-7 cells in a dose-dependent manner, induced cell apoptosis (typical morphological changes in nucleus, significant increase in cell apoptosis rate). The expressions of cleaved PARP and caspase-8 increased, while the expression of pro-caspase-3 decreased, which further verified sodium aescinate's effect in inducing cell apoptosis. Sodium aescinate significantly inhibited the phosphorylation of cell survival-related signal molecules (AKT, ERK) and down-regulate the activation of their common upstream kinase SRC. The findings indicated that sodium aescinate can block signals transiting to downstream molecules AKT, ERK, inhibit the proliferation of breast cancer cell MCF-7 cell apoptosis and induced cell apoptosis by suppressing the activation of SRC.