The roles of mitochondria in radiation-induced autophagic cell death in cervical cancer cells
The roles of mitochondria in radiation-induced autophagic cell death in cervical cancer cells
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线粒体在辐射诱导宫颈癌细胞自噬细胞死亡中的作用
DOI：
10.1007/s13277-015-4190-8
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发表时间：
2016-03-01
期刊：
影响因子：
--
通讯作者：
Liu, Xiaodong
中科院分区：
文献类型：
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作者：
Chen, Zongyan;Wang, Benli;Liu, Xiaodong
线粒体作为真核细胞的关键动力库，在调节细胞存活或死亡方面发挥着重要作用。在多种刺激下，受损的线粒体会产生大量的活性氧(ROS)，参与生命信号的调节，甚至可能决定癌细胞的命运。而线粒体在辐射诱导的自噬细胞死亡中的作用仍有待阐明。以人宫颈癌细胞株Hela为研究对象，利用基因工程技术建立SOD2沉默模型(SOD2-Ri)。用四甲基偶氮唑蓝(四甲基偶氮唑蓝)比色法检测细胞存活率，MitoTracker Green染色检测线粒体质量，Western印迹检测蛋白表达，流式细胞仪分析细胞内ROS水平、自噬和线粒体膜电位。电离辐射(IR)可诱导MAPLC3-II/MAPLC3-I比值增加，Beclin1表达增加，ROS生成增加，而MMP值降低，且呈时间依赖性。SOD2沉默后，IR引起的ROS变化和线粒体膜电位的变化明显增强。此外，SOD2-Ri细胞的放射敏感性和自噬能力均增强。然而，与SOD2-Ri相比，抗氧化剂NAC得到了相反的结果。线粒体电子传递链复合体II抑制剂噻吩甲酰三氟丙酮(TTFA)处理后，IR诱导的自噬、ROS和总细胞死亡增加。此外，基质金属蛋白酶的降低更为明显。然而，这些结果被环孢素A(CsA)逆转。IR可诱导Hela细胞产生ROS和线粒体损伤，导致自噬细胞死亡。
Mitochondria as the critical powerhouse of eukaryotic cells play important roles in regulating cell survival or cell death. Under numerous stimuli, impaired mitochondria will generate massive reactive oxygen species (ROS) which participate in the regulation of vital signals and could even determine the fate of cancer cells. While the roles of mitochondria in radiation-induced autophagic cell death still need to be elucidated. Human cervical cancer cell line, Hela, was used, and the SOD2 silencing model (SOD2-Ri) was established by gene engineering. Cell viability was detected by methyl thiazolyl tetrazolium (MTT) assays, MitoTracker Green staining was used to detect mitochondrial mass, Western blot was used to detect protein expression, and the level of ROS, autophagy, and mitochondrial membrane potential (MMP) were analyzed by flow cytometry. Ionizing radiation (IR) could induce the increase of MAPLC3-II/MAPLC3-I ratio, Beclin1 expression, and ROS generation but decrease the MMP in a time-dependent manner. After SOD2 silencing, the IR-induced changes of ROS and the MMP were significantly enhanced. Moreover, both the radio sensitivity and autophagy increased in SOD2-Ri cells. Whereas, compared with SOD2-Ri, the opposite results were obtained by NAC, an antioxidant. After the treatment with the inhibitor of mitochondrial electron-transport chain complex II, thenoyltrifluoroacetone (TTFA), the rate of autophagy, ROS, and the total cell death induced by IR increased. In addition, the decrease of MMP was more obvious. However, these results were reversed by cyclosporine A (CsA). IR could induce ROS generation and mitochondrial damage which lead to autophagic cell death in Hela cells.