The epidermal growth factor receptor modulates DNA double-strand break repair by regulating non-homologous end-joining
The epidermal growth factor receptor modulates DNA double-strand break repair by regulating non-homologous end-joining
复制标题
DOI：
10.1016/j.dnarep.2010.05.005
复制
发表时间：
2010-08-05
期刊：
影响因子：
3.8
通讯作者：
Dikomey, Ekkehard
中科院分区：
文献类型：
--
作者：
Kriegs, Malte;Kasten-Pisula, Ulla;Dikomey, Ekkehard
在哺乳动物细胞中，辐射引起的 DNA 损伤的修复似乎也受到表皮生长因子受体 (EGFR) 的控制，对 DNA 双链断裂 (DSB) 修复有特殊影响。本研究的目的是证明 EGFR 信号传导与 DNA DSB 修复之间的相互作用，并确定潜在的下游途径。我们特别想知道非同源末端连接 (NHEJ) 作为最重要的 DSB 修复途径在多大程度上参与了这种相互作用。通过计算照射后剩余 24 个的 γ H2AX 病灶来确定总体 DSB 修复，同时通过使用专门设计的稳定整合到基因组中的修复构建体来监测 NHEJ 活性。当 EGFR 被其天然配体 EGF 激活时，总体 DSB 修复能力明显增强，反之亦然，当 EGFR 被特异性抗体西妥昔单抗或酪氨酸激酶抑制剂厄洛替尼阻断时，总体 DSB 修复能力降低，其中厄洛替尼的降低明显更强。受影响的途径也存在差异。厄洛替尼会导致 MAPK 和 AKT 信号传导阻断，而西妥昔单抗仅影响 MAPK。正如特定抑制剂（PD98059、AKTIII）所证明的，EGFR 主要通过 MAPK 途径与 DSB 修复相互作用。对于两种不同报告细胞系（A549.EJ 和 H1299.EJ）测定的 NHEJ 活性，当 EGFR 被 EGF 激活时，活性显着增加，反之亦然，当 EGFR 信号传导被西妥昔单抗或厄洛替尼阻断时，NHEJ 活性降低。然而，所使用的两种抑制剂没有差异。仅当 ERK 受到 siRNA 影响时，EGFR 对 NHEJ 的调节才会被阻断，而当 AKT 被敲低时则不会。这些数据表明 EGFR 通过 MAPK 信号传导调节 NHEJ 来调节 DSB 修复。 (C) 2010 Elsevier B.V. 保留所有权利。
In mammalian cells repair of radiation-induced DNA damage appears to be also controlled by the epidermal growth factor receptor (EGFR) with a special impact on DNA double-strand break (DSB) repair. Aim of this study was to demonstrate this interaction between EGFR signalling and DNA DSB repair and to identify the underlying downstream pathways. We especially wanted to know in how far non-homologous end-joining (NHEJ) as the most important DSB repair pathway is involved in this interaction. Overall DSB repair was determined by counting gamma H2AX foci remaining 24 after irradiation, while NHEJ activity was monitored by using a specially designed repair construct stably integrated into the genome. The overall DSB repair capacity was clearly enhanced when EGFR was activated by its natural ligand EGF and, vice versa, was reduced when EGFR was blocked either by the specific antibody Cetuximab or the tyrosine kinase inhibitor erlotinib, whereby reduction was clearly stronger for erlotinib. There was also a difference in the pathways affected. While erlotinib lead to a block of both, MAPK as well as AKT signalling, Cetuximab only affected MAPK. As demonstrated by specific inhibitors (PD98059, AKTIII) EGFR interacts with DSB repair mostly via MAPK pathway. Also for NHEJ activity, there was a substantial increase, when EGFR was activated by EGF as determined for two different reporter cell lines (A549.EJ and H1299.EJ) and, vice versa, a reduction was seen when EGFR signalling was blocked by Cetuximab or erlotinib. There was, however, no difference for the two inhibitors used. This regulation of NHEJ by EGFR was only blocked when ERK was affected by siRNA but not when AKT was knocked down. These data indicate that EGFR modulates DSB repair by regulating NHEJ via MAPK signalling. (C) 2010 Elsevier B.V. All rights reserved.