人参皂甙Rg3诱导乳腺癌细胞系MCF-7凋亡的实验研究

Experimental Study on Apoptosis Induced by Ginsenoside Rg3 in Human MCF-7 Breast Cancer Cell Line

背景与目的:人参皂甙Rg3[20(R)-GinsenosideRg3]是从红参中提取的微量中药单体。近年研究表明人参皂甙Rg3尚具有抑制肿瘤细胞的增殖、抗肿瘤细胞浸润和转移等作用。肿瘤的发生和发展是一个极其复杂的过程,有多种转移相关的蛋白因子参与,并涉及多种转移途径和分子机制。人参皂甙Rg3抗肿瘤机制的研究为目前中药抗肿瘤研究热点之一。本研究的目的在于探讨Rg3抑制乳腺癌细胞的作用及其诱导凋亡的机制。材料与方法:四甲基偶氮唑蓝(3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide,MTT)法检测人乳腺癌细胞MCF-7的细胞增殖活力;荧光染色观察凋亡细胞的形态学变化;流式细胞术分析细胞周期及细胞凋亡;琼脂糖凝胶电泳测定DNA梯状带。结果:Rg3与MCF-7细胞生长抑制率之间有浓度依赖关系,相关系数(r)=0.953,Rg3处理细胞48h的IC50为71.91μg/ml;荧光显微镜下观察到经Rg3作用后,MCF-7细胞出现染色质凝集、核片段化、凋亡小体等凋亡形态学特征;流式细胞术检测表明Rg3能诱导细胞凋亡及调节细胞周期,用150μg/ml的Rg3处理细胞48h后,S期和G2-M期的细胞比率增加,G0-G1的细胞比率下降。细胞凋亡率从对照组的(0.45±0.25)%上升到(34.86±4.65)%。DNA琼脂糖凝胶电泳结果显示,服150μg/ml的Rg3处理细胞24h和48h后,能够使细胞产生明显的梯形电泳图谱(DNAladder)。结论:Rg3可通过诱导MCF-7细胞凋亡而发挥其抑制细胞增殖的作用。

BACKGROUND&AIM: Ginsenoside Rg3is a kind of effective chemical trace component extracted from the red panix.Many studies demonstrated that ginsenoside Rg3might block angiogenesis and inhibit tumor growth and metastasis.The mechanism of ginsenoside Rg3in anti-tumor is now one of hot point of chinese traditional medicine researches.The purpose of this study is to explore the effect of Rg3on induction apopotosis of human MCF-7breast cancer cell line. MATERAIL&METHODS: The cell proliferation inhibition was measured by3-[4,5-dimethylthiazo-2-yl]-2,5diphenyl tetrazolium bromide(MTT)assay.The morphological changes of cells were observed by fluorescence staining of Hoechst33258.Cell cycle and apoptosis rate were analyzed by flow cytometry.DNA ladder was showed by agarose gel electrophoresis. RESULTS: There was obviously a concentration-dependent relationship between Rg3and inhibition of the cell proliferation,r=0.953,(P<0.05).IC 50 was71.91μg/ml Rg3after treatment for48hours.The cells treated with150μg/ml Rg3for48hours showed morphological characteristics of apoptotic cells with the condensed chromatin,the nuclear fragmentation,the apoptotic body and brighter green fluorescent.FCM assay indicated that Rg3regulated cell cycle and induced cell apoptosis.The percentage of cells in S phase and G 2 -M phase was increased,whereas the percentage of cells in G 0 -G 1 was decreased.The apoptosis rates were increased from(0.45±0.25)%to (34.86±4.65)%in MCF-7cells after treatment with Rg3for48hours.The cells treated with150μg/ml Rg3for24and48hours reveal an obvious DNA ladder. CONCLUSION: The results suggested that Ginsenoside Rg3exerts an inhibiting effect on human MCF-7breast cancer cell line by inducing apoptosis of the cells.