Role of ROS-mediated autophagy in radiation-induced bystander effect of hepatoma cells
Role of ROS-mediated autophagy in radiation-induced bystander effect of hepatoma cells
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ROS介导的自噬在辐射诱导的肝癌细胞旁观者效应中的作用
DOI：
10.3109/09553002.2015.1012308
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发表时间：
2015-05-01
影响因子：
2.6
通讯作者：
Shao, Chunlin
中科院分区：
文献类型：
--
作者：
Wang, Xiangdong;Zhang, Jianghong;Shao, Chunlin
摘要目的：自噬在细胞对电离辐射的反应中起着重要作用，但自噬是否能调节辐射诱导的旁观者效应（里贝）尚不清楚。在此，我们研究了旁观者损伤和自噬在人肝癌细胞HepG 2中的关系。材料与方法：用3戈伊γ射线照射HepG 2细胞后收集条件培养液（CM）处理HepG 2细胞4、12和24 h，然后检测旁观者HepG 2细胞微核（MN）、细胞内活性氧（ROS）、线粒体膜电位（MMP）以及微管相关蛋白1轻链3（LC 3）和Beclin-1蛋白表达。在一些实验中，分别用LC 3小干扰RNA（siRNA）、Beclin-1 siRNA转染旁观者HepG 2细胞或用1%二甲基亚砜（DMSO）处理旁观者HepG 2细胞。结果：在旁观者细胞中诱导了额外的MN和线粒体功能障碍以及ROS。旁观者细胞中自噬蛋白标志物LC 3-II/LC 3-I和Beclin-1的表达增加。DMSO可显著抑制旁观者MN的诱导以及LC 3和Beclin-1的过度表达。而当用LC 3 siRNA或Beclin-1 siRNA转染旁观者细胞时，旁观者MN的产量显著增加。结论：ROS升高具有平衡旁观者效应的双重作用。一种是引起MN，另一种是诱导保护性自噬。
Abstract Purpose: Autophagy plays a crucial role in cellular response to ionizing radiation, but it is unclear whether autophagy can modulate radiation-induced bystander effect (RIBE). Here, we investigated the relationship between bystander damage and autophagy in human hepatoma cells of HepG2. Materials and methods: HepG2 cells were treated with conditioned medium (CM) collected from 3 Gy γ-rays irradiated hepatoma HepG2 cells for 4, 12, or 24 h, followed by the measurement of micronuclei (MN), intracellular reactive oxygen species (ROS), mitochondrial membrane potential (MMP), and protein expressions of microtubule-associated protein 1 light chain 3 (LC3) and Beclin-1 in the bystander HepG2 cells. In some experiments, the bystander HepG2 cells were respectively transfected with LC3 small interfering RNA (siRNA), Beclin-1 siRNA or treated with 1% dimethyl sulfoxide (DMSO). Results: Additional MN and mitochondrial dysfunction coupled with ROS were induced in the bystander cells. The expressions of protein markers of autophagy, LC3-II/LC3-I and Beclin-1, increased in the bystander cells. The inductions of bystander MN and overexpressions of LC3 and Beclin-1 were significantly diminished by DMSO. However, when the bystander cells were transfected with LC3 siRNA or Beclin-1 siRNA, the yield of bystander MN was significantly enhanced. Conclusion: The elevated ROS have bi-functions in balancing the bystander effects. One is to cause MN and the other is to induce protective autophagy.