ATR-dependent radiation-induced γH2AX foci in bystander primary human astrocytes and glioma cells
ATR-dependent radiation-induced γH2AX foci in bystander primary human astrocytes and glioma cells
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DOI：
10.1038/sj.onc.1209863
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发表时间：
2007-02-01
期刊：
影响因子：
8
通讯作者：
Prise, K. M.
中科院分区：
文献类型：
--
作者：
Burdak-Rothkamm, S.;Short, S. C.;Prise, K. M.
放射治疗是高度恶性胶质瘤的重要治疗手段。非靶向（旁观者）效应可能影响这些细胞对辐射的反应，因此，对这些效应的研究可能为放射敏感性和放射治疗反应的机制提供新的见解，并为治疗方法提供新的靶点。利用Gray癌症研究所针对单个细胞的微束设备，用氦离子照射正常的原代人星形胶质细胞（NHA）和T98G胶质瘤细胞。辐照后的NHA和T98G胶质瘤细胞产生的信号在照射后48小时内诱导邻近的非靶向旁观者细胞发生γ - H2AX灶。在针对NHA或T98G细胞的共培养和培养基转移实验中也观察到γ - H2AX旁观者灶。二甲基亚砜、Filipin和抗转化生长因子(TGF)- β 1可抑制旁观者细胞中的γ - H2AX灶，证实了活性氧（reactive oxygen species， ROS）和膜介导信号参与了旁观者信号通路。此外，tgf - β 1以ROS依赖的方式诱导γ - H2AX，类似于旁观者病灶。观察到T98G胶质瘤细胞和正常人星形胶质细胞在旁观者病灶诱导中的ROS和膜信号依赖性差异。抑制共济失调毛细血管扩张突变（ATM）蛋白和DNA-PK不能抑制旁观者γ - H2AX灶的诱导，而ATM-和rad3相关（ATR）的突变可以消除旁观者灶的诱导。此外，atr依赖性旁观者病灶诱导仅限于s期细胞。这些观察结果可能为利用旁观者效应提供额外的治疗靶点。
Radiotherapy is an important treatment for patients suffering from high-grade malignant gliomas. Non-targeted ( bystander) effects may influence these cells' response to radiation and the investigation of these effects may therefore provide new insights into mechanisms of radiosensitivity and responses to radiotherapy as well as de. ne new targets for therapeutic approaches. Normal primary human astrocytes ( NHA) and T98G glioma cells were irradiated with helium ions using the Gray Cancer Institute microbeam facility targeting individual cells. Irradiated NHA and T98G glioma cells generated signals that induced gamma H2AX foci in neighbouring non-targeted bystander cells up to 48 h after irradiation. gamma H2AX bystander foci were also observed in co-cultures targeting either NHA or T98G cells and in medium transfer experiments. Dimethyl sulphoxide, Filipin and antitransforming growth factor (TGF)-beta 1 could suppress gamma H2AX foci in bystander cells, confirming that reactive oxygen species (ROS) and membrane-mediated signals are involved in the bystander signalling pathways. Also, TGF-beta 1 induced gamma H2AX in an ROS- dependent manner similar to bystander foci. ROS and membrane signalling-dependent differences in bystander foci induction between T98G glioma cells and normal human astrocytes have been observed. Inhibition of ataxia telangiectasia mutated (ATM) protein and DNA-PK could not suppress the induction of bystander gamma H2AX foci whereas the mutation of ATM- and rad3-related (ATR) abrogated bystander foci induction. Furthermore, ATR-dependent bystander foci induction was restricted to S-phase cells. These observations may provide additional therapeutic targets for the exploitation of the bystander effect.