Cucurbitacin E induces caspase-dependent apoptosis and protective autophagy mediated by ROS in lung cancer cells
Cucurbitacin E induces caspase-dependent apoptosis and protective autophagy mediated by ROS in lung cancer cells
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DOI：
10.1016/j.cbi.2016.04.028
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发表时间：
2016-06-25
影响因子：
5.1
通讯作者：
Chen, Xiuping
中科院分区：
文献类型：
--
作者：
Ma, Guixin;Luo, Weiwei;Chen, Xiuping
葫芦素E （cuurbitacin E, CuE）是一种具有抗癌活性的三萜化合物，其作用机制尚不明确。本研究探讨了CuE对95D肺癌细胞的抗癌作用。CuE降低细胞活力，抑制菌落形成，并以浓度依赖的方式增加活性氧（ROS），而n-乙酰- l-半胱氨酸（NAC）可以逆转这种作用。通过JC-1染色、Bcl-2家族蛋白表达、caspases裂解和TUNEL染色检测CuE诱导细胞凋亡。NAC和Ac-DEVD-CHO部分逆转了cue诱导的caspase-3、caspase-7和PARP的切割。此外，CuE引起自噬液泡的积累以及LC3II蛋白的浓度和时间依赖性表达。自噬抑制剂氯喹和巴菲霉素A1增强了cue诱导的LC3II表达和细胞死亡。NAC预处理可部分逆转线索触发的p-AKT、p-mTOR、Beclin-1和p-ULK1的蛋白表达。此外，免疫荧光证实，CuE治疗损伤了f -肌动蛋白，但不影响b-微管蛋白。由此可见，CuE可通过Bcl-2家族和caspase诱导95D肺癌细胞ros依赖性凋亡。此外，CuE通过AKT/mTOR途径诱导ROS介导的保护性自噬。本研究提供了ROS在CuE抗癌作用中的新作用。2016爱思唯尔爱尔兰有限公司版权所有。
Cucurbitacin E (CuE) is a triterpenoid with potent anticancer activities while the underlying mechanisms remain elusive. In the present study, the anticancer effects of CuE on 95D lung cancer cells were investigated. CuE decreased cell viability, inhibited colony formation, and increased reactive oxygen species (ROS) in a concentration-dependent manner, which were reversed by N-acetyl-L-cysteine (NAC). CuE induced apoptosis as determined by JC-1 staining, expression of Bcl-2 family proteins, cleavage of caspases, and TUNEL staining. NAC and Ac-DEVD-CHO partially reversed CuE-induced cleavage of caspase-3, caspase-7, and PARP. Furthermore, CuE caused accumulation of autophagic vacuoles and concentration-and time-dependent expression of LC3II protein. Autophagy inhibitors chloroquine and bafilomycin A1 enhanced CuE-induced LC3II expression and cell death. CuE-triggered protein expression of p-AKT, p-mTOR, Beclin-1, and p-ULK1 was partially reversed by NAC pretreatment. In addition, CuE treatment damaged F-actin without affecting b-tubulin as confirmed by immunofluorescence. In conclusion, CuE induced ROS-dependent apoptosis through Bcl-2 family and caspases in 95D lung cancer cells. Furthermore, CuE induced protective autophagy mediated by ROS through AKT/mTOR pathway. This study provides novel roles of ROS in the anticancer effect of CuE. (C) 2016 Elsevier Ireland Ltd. All rights reserved.