五环三萜类单体诱导人乳腺癌细胞凋亡的研究

Studies of Pentacyclic Triterpenoid-Induced Apoptosis in Human Breast Carcinoma Cells

目的:探讨熊果酸、齐墩果酸和18β-甘草次酸对人乳腺癌细胞(MCF-7)诱导凋亡的作用,并探讨凋亡发生与细胞内Ca2+浓度变化的关系。方法:选用不同浓度梯度的熊果酸、齐墩果酸和18β-甘草次酸分别处理MCF-7细胞24h,用MTT比色法测定细胞增殖能力,用末端脱氧核苷酸转移酶介导dUTP末端标记法和an-nexin V流式细胞仪法检测细胞凋亡率,用Fura-2荧光负载方法测定细胞内Ca2+浓度。结果:熊果酸、齐墩果酸和18β-甘草次酸的半增殖抑制浓度(IC50)分别为36.18、88.36和234.33μmol/L;20μmol/L和30μmol/L熊果酸、75μmol/L和100μmol/L齐墩果酸及100μmol/L和150μmol/L18β-甘草次酸使细胞凋亡率显著升高(P<0.01和P<0.05);20μmol/L熊果酸、75μmol/L齐墩果酸和150μmol/L18β-甘草次酸处理组的细胞内Ca2+浓度明显高于对照组(P<0.05)。结论:熊果酸、齐墩果酸和18β-甘草次酸均具有诱导MCF-7细胞凋亡而抑制其增殖的作用;其诱导凋亡可能依赖于细胞内Ca2+水平上调。

Objective： To investigate the effects of ursolic acid （ UA）, oleanolic acid （OA） and 18 β - glycyrrhetinic acid （GA） on induction of apoptosis, and relationship between apoptosis and intracellular Ca2＋ concentration in human breast carcinoma（ MCF - 7 ） cells. Methods： After MCF - 7 cells were treated with UA, OA and GA for 24h, cell viability of proliferation was assessed by MTT assay, the rates of cell apoptosis were examined by terminal deoxynucleotide transferase mediated dUTP nick - end - labeling method and flow cytometry with annexin V/propidium iodide fluorescent stain, and intracellular Ca2＋ concentration was measured by Fure -2 fluorescein load method. Results.lCso of UA,OA and GA -inhibited proliferation were 36. 18μmol/L, 88. 36μmol/L and 234. 331.tmol/L respectively. Treated with 201.tmol/L and 301xmol/L UA,751μmol/L and 100μmol/L OA, and 100μmol/L and 150μmol/L GA,the rates of cell apoptosis were in- creased significantly（ P 〈 0. 01 and P 〈 0. 05 ）. lntracelhdar Ca2 ＋ cocentration after treatment with 201μmol/L UA, 751xmol/L OA and 150μmol/L GA was higher evidently than that of control （P 〈 0. 05 ）. Conclusion： UA, OA and GA have effects of inhibition proliferation through induction apoptosis in MCF - 7 cells. The apoptosis induced by UA, OA and GA may depend on rise of intracellular Ca^2＋ concentration.