Yan Xiaofei, Liang FenLi, Li Dongmin, Zheng Jin
Department of Biochemistry and Molecular Biology, Medical School, Xi'an Jiaotong University, Xi'an, 710061, Shaanxi, People's Republic of China,
Mol Cell Biochem. 2015 Jan;398(1-2):95-104. doi: 10.1007/s11010-014-2208-y. Epub 2014 Sep 13.
Excessive reactive oxygen species (ROS) generation has been implicated as one of main agents in ouabain-induced anticancer effect. Unfortunately, the signaling pathways under it are not very clarified. In the present study, we investigated the molecular mechanism involved in ouabain-induced ROS generation and cell apoptosis on human U373MG and U87MG glioma cells. Ouabain-induced glioblastoma cells apoptosis and increased ROS generation. Clearance ROS by three different ROS scavenger partly, but not totally, reversed ouabain's effect on cell apoptosis. Ouabain-induced ROS generation was not regulated by calcium overload, reduced nicotinamide adenine dinucleotide phosphate oxidation, but by p66Shc phosphorylation. Ouabain treatment increased p66Shc Ser36 phosphorylation. Knockdown of p66Shc by siRNA significantly inhibited ROS generations in response to ouabain. Ouabain-induced p66Shc phosphorylation through Src/Ras/extracellular signal-regulated kinase signal pathway. Our results uncovered a novel signaling pathway with p66Shc, ouabain-induced ROS generation, and glioblastoma cell apoptosis.
过量的活性氧（ROS）生成被认为是哇巴因诱导抗癌作用的主要因素之一。不幸的是，其背后的信号通路尚不完全清楚。在本研究中，我们调查了哇巴因诱导人U373MG和U87MG胶质瘤细胞产生ROS及细胞凋亡的分子机制。哇巴因诱导胶质母细胞瘤细胞凋亡并增加ROS生成。三种不同的ROS清除剂部分但并非完全逆转了哇巴因对细胞凋亡的作用。哇巴因诱导的ROS生成不受钙超载、还原型烟酰胺腺嘌呤二核苷酸磷酸氧化的调节，而是受p66Shc磷酸化的调节。哇巴因处理增加了p66Shc Ser36磷酸化。用小干扰RNA敲低p66Shc可显著抑制对哇巴因产生的ROS生成。哇巴因通过Src/Ras/细胞外信号调节激酶信号通路诱导p66Shc磷酸化。我们的结果揭示了一条涉及p66Shc、哇巴因诱导的ROS生成和胶质母细胞瘤细胞凋亡的新信号通路。
