齐墩果酸衍生物SZC014同时诱导乳腺癌细胞的凋亡和自噬

Dual Induction of Apoptosis and Autophagy in Breast Cancer Cells by SZC014 of Oleanolic Acid Derivative

目的:齐墩果酸(OA)具有多种药理学作用,如肝保护、抗炎、抗氧化及抗肿瘤等。然而,它的活性相对较弱并且生物利用度低,使其临床应用受到限制。在本研究中,我们合成一种新的OA衍生物—SZC014,并研究它们在乳腺癌细胞中的抗肿瘤作用及其作用机制。方法:应用MTT法测定空白对照组、不同浓度OA及SZC014处理后的乳腺癌细胞的存活率。应用PI染色流式细胞术测定SZC014对细胞周期的影响。通过倒置相差显微镜和透射电子显微镜观察并拍摄SZC014处理后的细胞形态学和超微结构的变化。应用Westernblot分别测定SZC014处理后凋亡相关蛋白、自噬相关蛋白表达的变化情况。结果:MTT实验证明,SCZ014可抑制乳腺癌细胞的增殖,并且其生长抑制作用强于OA。PI染色流式细胞术证明SZC014诱MCF-7细胞周期停滞于G2/M期。倒置相差显微镜和透射电子显微镜证明SZC014处理的MCF-7细胞中凋亡和自噬同时被发现。Westernblot结果提示SZC014可能通过线粒体途径诱导MCF-7细胞凋亡。此外,SZC014诱导Beclin1与ATG5的上调可能与MCF-7细胞自噬相关。结论:SZC014作为一种新的OA衍生物,表现出较OA更强的抗乳腺癌活性,且这种抗肿瘤作用可能与凋亡及自噬相关。

Objective: Oleanolic acid(OA) possesses various pharmacological actions, such as hepatoprotection, anti-inflammation, antioxidation and antitumor. However, its clinical applications are limited by its relatively weak activities and low bioavailability. In this study, we synthetised a kind of new OA derivative, i.e. SZC014 [2-( Pyrrolidine-1- yl) methyl-3- oxo- olean-12-en-28-oic acid], and its anticancer effect on breast cancer cells and mechanisms were investigated. Methods: The survival rate of breast cancer cells intervened by SZC014( MCF- 7, MDA-MB-435, MDA-MB-231) was detected by using MTT. The effect of SZC014 on cell cycle was identified by PI staining assay. The cellular morphological changes and ultrastructural structures affected by SZC014 were observed and imaged through inverted phase contrast microscope and transmission electron microscopy. Western blotting was performed to explore the proteins expression associated with apoptosis(pro-caspase 9, cleaved-caspase 9, pro-caspase 3, cleaved-caspase 3, cyto-c, Bax, Bcl-2 and Bcl-xL), and autophagy (Beclin 1 and ATG5) respectively. Results: SZC014 could inhibit the proliferation of breast cancer cells, and its action was stronger than OA. SZC014 induced MCF-7 cells stay at G2/M phase in terms of PI staining assay. Both apoptosis and autophagy were found simultaneously in MCF-7 cells intervened by SZC014. SZC014 could induce the apoptosis of MCF-7 through mitochondrial pathway. The up-regulation of Beclin 1 and ATG 5 was inferred to be involved in SZC014-induced autophagy. Conclusion: SZC014 possessed more potent anticancer activity than OA in breast cancer cells, which may be related to apoptosis and autophagy.