Inhibition of tryptophan 2,3-dioxygenase impairs DNA damage tolerance and repair in glioma cells.
Inhibition of tryptophan 2,3-dioxygenase impairs DNA damage tolerance and repair in glioma cells.
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色氨酸2，3-双加氧酶的抑制损害神经胶质瘤细胞的DNA损伤耐受性和修复。
DOI：
10.1093/narcan/zcab014
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发表时间：
2021-06
期刊：
影响因子：
5.1
通讯作者：
Eoff RL
中科院分区：
文献类型：
--
作者：
Reed MR;Maddukuri L;Ketkar A;Byrum SD;Zafar MK;Bostian ACL;Tackett AJ;Eoff RL
色氨酸2，3-双加氧酶（TDO）的表达是通过犬尿氨酸（KYN）信号传导的胶质瘤恶性的决定因素。我们报告说，抑制TDO活性衰减恢复复制应力和增加的遗传毒性作用的双-氯乙基亚硝基脲（BCNU）。当TDO活性在BCNU治疗前被阻断时，复制应激反应（RSR）的Chk 1臂的激活减少，而复制蛋白A（RPA）上的丝氨酸33（pS33）的磷酸化增强-指示增加叉崩溃。定量蛋白质组学结果的分析表明，TDO抑制降低核53 BP 1和沉默调节蛋白水平。我们证实，缺乏TDO活性的细胞在BCNU处理后表现出γ-H2 AX信号升高和53 BP 1向染色质的募集缺陷，这与DNA断裂的延迟修复相对应。外源性KYN的加入增加了断裂修复率。TDO抑制减少了SIRT 7去乙酰化酶向染色质的募集，这增加了组蛋白H3 K18乙酰化-一种参与防止53 BP 1募集到DNA损伤位点的关键标记。TDO抑制也致敏细胞电离辐射（IR）诱导的损伤，但这种影响并不涉及改变53 BP 1招聘。这些实验支持一种模型，其中TDO介导的KYN信号传导有助于激发对复制应激和DNA损伤的强烈反应。神经胶质瘤细胞中的复制应激和DNA损伤反应由色氨酸2，3-双加氧酶活性调节，色氨酸2，3-双加氧酶活性是控制犬尿氨酸信号传导和NAD+从头合成的关键因素。
Expression of tryptophan 2,3-dioxygenase (TDO) is a determinant of malignancy in gliomas through kynurenine (KYN) signaling. We report that inhibition of TDO activity attenuated recovery from replication stress and increased the genotoxic effects of bis-chloroethylnitrosourea (BCNU). Activation of the Chk1 arm of the replication stress response (RSR) was reduced when TDO activity was blocked prior to BCNU treatment, whereas phosphorylation of serine 33 (pS33) on replication protein A (RPA) was enhanced—indicative of increased fork collapse. Analysis of quantitative proteomic results revealed that TDO inhibition reduced nuclear 53BP1 and sirtuin levels. We confirmed that cells lacking TDO activity exhibited elevated gamma-H2AX signal and defective recruitment of 53BP1 to chromatin following BCNU treatment, which corresponded with delayed repair of DNA breaks. Addition of exogenous KYN increased the rate of break repair. TDO inhibition diminished SIRT7 deacetylase recruitment to chromatin, which increased histone H3K18 acetylation—a key mark involved in preventing 53BP1 recruitment to sites of DNA damage. TDO inhibition also sensitized cells to ionizing radiation (IR)-induced damage, but this effect did not involve altered 53BP1 recruitment. These experiments support a model where TDO-mediated KYN signaling helps fuel a robust response to replication stress and DNA damage. The replication stress and DNA damage responses in glioma cells are modulated by tryptophan 2,3-dioxygenase activity, a key factor controlling kynurenine signaling and de novo synthesis of NAD+.