Auranofin, an inhibitor of thioredoxin reductase, induces apoptosis in hepatocellular carcinoma Hep3B cells by generation of reactive oxygen species
Auranofin, an inhibitor of thioredoxin reductase, induces apoptosis in hepatocellular carcinoma Hep3B cells by generation of reactive oxygen species
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DOI：
10.4149/gpb_2016043
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发表时间：
2017-04-01
影响因子：
1.5
通讯作者：
Choi, Yung Hyun
中科院分区：
文献类型：
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作者：
Hwang-Bo, Hyun;Jeong, Jin-Woo;Choi, Yung Hyun
哺乳动物硫氧还蛋白还原酶（TrxR）在恢复被活性氧（ROS）产生和氧化损伤破坏的细胞氧化还原平衡中起着至关重要的作用。在这里，我们评估了金诺芬，一种选择性的TrxR抑制剂，是否可以作为一个潜在的抗癌药物，通过其选择性靶向的TrxR活性在Hep 3B肝癌细胞。金诺芬处理降低了这些细胞的TrxR活性并诱导凋亡，这伴随着死亡受体（DR）的上调和半胱天冬酶的激活，以及促进聚（ADP-核糖）-聚合酶的蛋白水解降解。用泛半胱天冬酶抑制剂治疗逆转了金诺芬诱导的细胞凋亡和生长抑制，表明金诺芬可能通过涉及内源性和外源性凋亡途径的半胱天冬酶依赖性机制诱导细胞凋亡。金诺芬还显著改变线粒体功能，通过调节Bcl-2家族蛋白促进线粒体膜透化和细胞色素c释放;这些事件伴随着ROS的积累。用ROS猝灭剂抑制ROS产生显著减弱了经奥拉诺芬处理的细胞中TrxR的失活，并且几乎完全抑制了奥拉诺芬诱导的DR上调和半胱天冬酶的活化，从而防止了奥拉诺芬诱导的细胞凋亡和细胞活力丧失。总之，这些发现表明金诺芬抑制Hep 3B细胞中的TrxR活性激活ROS和半胱天冬酶依赖性凋亡信号通路并触发癌细胞死亡。
Mammalian thioredoxin reductase (TrxR) plays a vital role in restoring cellular redox balance disrupted by reactive oxygen species (ROS) generation and oxidative damage. Here, we evaluated whether auranofin, a selective inhibitor of TrxR, could serve as a potential anti-cancer agent through its selective targeting of TrxR activity in Hep3B hepatocellular carcinoma cells. Auranofin treatment reduced the TrxR activity of these cells and induced apoptosis, which were accompanied by up-regulation of death receptors (DRs) and activation of caspases, as well as promotion of proteolytic degradation of poly(ADP-ribose)-polymerase. Treatment with a pan-caspase inhibitor reversed the auranofin-induced apoptosis and growth suppression, indicating that auranofin may induce apoptosis through a caspasedependent mechanism involving both the intrinsic and extrinsic apoptotic pathways. Auranofin also significantly altered mitochondrial function, promoting mitochondrial membrane permeabilization and cytochrome c release by regulating Bcl-2 family proteins; these events were accompanied by an accumulation of ROS. Inhibition of ROS generation with the ROS quencher significantly attenuated the inactivation of TrxR in auranofin-treated cells and almost completely suppressed the auranofin-induced up-regulation of DRs and activation of caspases, thereby preventing auranofin-induced apoptosis and loss of cell viability. Taken together, these findings indicate that auranofin inhibition of TrxR activity in Hep3B cells activates ROS-and caspase-dependent apoptotic signaling pathways and triggers cancer cell death.