Specific killing of DNA damage-response deficient cells with inhibitors of poly(ADP-ribose) glycohydrolase.
Specific killing of DNA damage-response deficient cells with inhibitors of poly(ADP-ribose) glycohydrolase.
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DOI：
10.1016/j.dnarep.2017.02.010
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发表时间：
2017-04
期刊：
影响因子：
3.8
通讯作者：
Bryant HE
中科院分区：
文献类型：
--
作者：
Gravells P;Grant E;Smith KM;James DI;Bryant HE
提出了聚（ADP-核糖）糖水解酶（PARG）的合成致死筛选。使用 SiRNA 和 PARG 抑制剂棓单宁和 PDD00017273。 PARG 与 BRCA1、BRCA2、PALB2、FAM175A (ABRAXAS) 和 BARD1 具有综合致死性。 PARG 抑制会诱导 DNA 损伤、复制叉停滞和同源重组。这些数据支持 PARG 作为治疗靶点的有效性。 DNA 损伤后蛋白质的聚（ADP-核糖基化）已得到充分研究，并且使用聚（ADP-核糖）聚合酶（PARP）抑制剂作为治疗剂对于治疗许多癌症具有令人兴奋的前景。聚（ADP-核糖）糖水解酶 (PARG) 具有糖苷内切酶和糖苷外切酶活性，可以裂解糖苷键，快速逆转 PARP 酶的作用。与通过 PARP 添加聚（ADP-核糖）（PAR）一样，通过 PARG 去除 PAR 也被认为是修复 DNA 链断裂和在受干扰的分叉处继续复制所必需的。在这里，我们使用 siRNA 显示 PARG 与 BRCA1、BRCA2、PALB2、FAM175A (ABRAXAS) 和 BARD1 之间的合成致死关系。此外，我们还证明，耗尽这些蛋白质的 MCF7 细胞对棓单宁和新型特异性 PARG 抑制剂 PDD00017273 敏感。我们证实，PARG 抑制会增加内源性 DNA 损伤，使复制叉停滞并增加同源重组，并提出，PARG 抑制剂诱导的复制叉停滞中缺乏同源重组 (HR) 蛋白，从而诱导细胞死亡。有趣的是，并非所有对 PARP 具有综合致死性的基因都会导致对 PARG 抑制剂的敏感性，这表明尽管存在重叠，但 PARP 和 PARG 的功能可能并不完全相同。这些数据共同进一步证明了 PARG 抑制剂的单一治疗可用于治疗某些 HR 缺陷肿瘤的可能性，并提供了对 PARP、PARG 与 DNA 修复过程之间关系的深入了解。
A synthetic lethal screen for Poly(ADP-ribose)glycohydrolase (PARG) is presented. SiRNA and the PARG inhibitors Gallotannin and PDD00017273 are used. PARG is synthetically lethal with BRCA1, BRCA2, PALB2, FAM175A (ABRAXAS) and BARD1. PARG inhibition induces DNA damage, stalled replication forks and homologous recombination. The data support the validity of PARG as a target for therapy. Poly(ADP-ribosylation) of proteins following DNA damage is well studied and the use of poly(ADP-ribose) polymerase (PARP) inhibitors as therapeutic agents is an exciting prospect for the treatment of many cancers. Poly(ADP-ribose) glycohydrolase (PARG) has endo- and exoglycosidase activities which can cleave glycosidic bonds, rapidly reversing the action of PARP enzymes. Like addition of poly(ADP-ribose) (PAR) by PARP, removal of PAR by PARG is also thought to be required for repair of DNA strand breaks and for continued replication at perturbed forks. Here we use siRNA to show a synthetic lethal relationship between PARG and BRCA1, BRCA2, PALB2, FAM175A (ABRAXAS) and BARD1. In addition, we demonstrate that MCF7 cells depleted of these proteins are sensitive to Gallotannin and a novel and specific PARG inhibitor PDD00017273. We confirm that PARG inhibition increases endogenous DNA damage, stalls replication forks and increases homologous recombination, and propose that it is the lack of homologous recombination (HR) proteins at PARG inhibitor-induced stalled replication forks that induces cell death. Interestingly not all genes that are synthetically lethal with PARP result in sensitivity to PARG inhibitors, suggesting that although there is overlap, the functions of PARP and PARG may not be completely identical. These data together add further evidence to the possibility that single treatment therapy with PARG inhibitors could be used for treatment of certain HR deficient tumours and provide insight into the relationship between PARP, PARG and the processes of DNA repair.