熊果酸诱导人乳腺癌细胞MCF-7凋亡的实验研究

目的:探讨三萜类中药成分熊果酸(Ursolic Acid,UA)诱导乳腺癌MCF-7细胞的凋亡作用,从而为开发应用于治疗乳腺癌的药物提供科学依据.方法:应用细胞培养技术,用不同浓度的药物在一定的时间内处理MCF-7细胞,采用MTT法、活细胞原位光镜和荧光染色技术、流式细胞技术(FCM)、荧光免疫组织化学技术,研究药物诱导细胞凋亡引起的形态改变、细胞周期变化、p 53蛋白表达.结果:UA剂量依赖性的抑制MCF-7细胞增殖,半数生长抑制剂量(IC50)为22.6±3.0 μmol/L,凋亡促进因子p 53蛋白表达量增加,有典型的凋亡形态学特征,核质向边缘固缩,有凋亡小体.结论:UA通过抑制MCF-7细胞生长和上调p 53的表达诱导细胞凋亡发挥其抗肿瘤细胞的作用.

Experimental Study on MCF-7 Cell Apoptosis Induced by Ursolic Acid

OBJECTIVE: To study the effects of ursolic acid (UA), apentacyclic triterpene acid, on MCF-7 cell apoptosis. METHODS: MCF-7 cells were cultured with different concentrations of UA. Viability of UA-induced MCF-7 cells was evaluated by MTT assay. Cell cycle and sub-G1 peak were performed by FCM. Morphologic changes of UA-treated cells were observed by light microscope. Apoptotic cells with condensed or fragmented nuclei were visualized by Ho33258 and PI staining by a fluorescence microscope (EX: U.V., Green light). p 53 protein expression was analyzed by fluorescence immunohistochemical method (SABC-Cy3). RESULT: 24 hours after UA treatment, inhibition of MCF-7 cell proliferation was concentration-dependent. The IC50 value for UA was 22.6 +/- 3.0 micromol/L. Cell cycle analysis by FCM showed that 50 micromol/L of the drug arrested MCF-7 cell cycle at G0-G1 phase. Morphological changes of MCF-7 cells exhibited many of the hallmark features of apoptosis, including condensation of chromatin and DNA fragmentation. UA increased p 53 protein expression. CONCLUSION: The results suggest that UA evokes MCF-7 cell apoptosis is correlation with the up-regulation of p 53. The study indicated that UA might be a potential Chinese medical component for breast neoplasm.