Cyclovirobuxine D Induces Autophagy-Associated Cell Death via the Akt/mTOR Pathway in MCF-7 Human Breast Cancer Cells
Cyclovirobuxine D Induces Autophagy-Associated Cell Death via the Akt/mTOR Pathway in MCF-7 Human Breast Cancer Cells
复制标题
环维黄杨星 D 在 MCF-7 人乳腺癌细胞中通过 Akt/mTOR 途径诱导自噬相关细胞死亡
DOI：
10.1254/jphs.14013fp
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发表时间：
2014-05-01
影响因子：
3.5
通讯作者：
Liu, Peiqing
中科院分区：
文献类型：
--
作者：
Lu, Jing;Sun, Duanping;Liu, Peiqing
自噬是一个高度调节的多步骤生物过程，用于清除受损的细胞质成分和细胞器。已经表明，自噬的激活可能是通过触发细胞死亡来治疗癌症的有希望的治疗策略。本文报道了中药环维黄杨星D（cyclovibuxine D，CVB-D）对人乳腺癌MCF-7细胞自噬的诱导作用。CVB-D以浓度和时间依赖性方式抑制MCF-7细胞的活力。自噬的激活通过透射电子显微镜、单丹酰尸胺染色和自噬标记物微管相关蛋白1轻链3（LC 3）的表达来表征。CVB-D处理后，观察到自噬体的明显积聚，伴随着LC 3荧光点的升高。Western blot分析显示，CVB-D显著促进了LC 3-I向LC 3-II的转化和自噬相关蛋白5（ATG 5）的表达，这两个蛋白在自噬体的形成中起重要作用。另一方面，CVB-D诱导的自噬和细胞活力的降低可以被3-甲基腺嘌呤阻断，3-甲基腺嘌呤是一种成熟的自噬抑制剂。此外，CVB-D减弱了Akt和mTOR的磷酸化，这两个自噬途径中的关键抑制因子。这些发现为CVB-D的药理作用和机制提供了新的线索，并可能支持自噬诱导剂在癌症治疗中的潜在用途。
Autophagy is a highly regulated and multi-step biological process that serves to remove damaged cytoplasmic components and organelles. It has been suggested that the activation of autophagy may be a promising therapeutic strategy for cancer treatment by triggering cell death. In this study, we reported that cyclovirobuxine D (CVB-D), an alkaloid component in a traditional Chinese herb, could induce autophagy in the MCF-7 human breast cancer cell line. CVB-D inhibited the viability of MCF-7 cells in a concentration- and time-dependent manner. Activation of autophagy was characterized by transmission electron microscopy, monodansylcadaverine staining, and expression of autophagy marker microtubule-associated protein 1 light chain 3 (LC3). After CVB-D treatment, a clear accumulation of autophagosomes was observed accompanied with elevated LC3 fluorescent puncta. Western blot analysis revealed that CVB-D significantly promoted the conversion from LC3-I to LC3-II and the expression of autophagy-related protein 5 (ATG5), which are both essential for autophagosome formation. On the other hand, CVB-D induced autophagy and decrease in cell viability could be blocked by 3-methyladenine, a well-established autophagy inhibitor. Moreover, CVB-D attenuated the phosphorylation of Akt and mTOR, two pivotal suppressors in autophagy pathways. These findings shed new light on the pharmacological actions and mechanism of CVB-D and may support the potential utility of autophagy inducers in cancer treatment.