TDP1 is Critical for the Repair of DNA Breaks Induced by Sapacitabine, a Nucleoside also Targeting ATM- and BRCA-Deficient Tumors.
TDP1 is Critical for the Repair of DNA Breaks Induced by Sapacitabine, a Nucleoside also Targeting ATM- and BRCA-Deficient Tumors.
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DOI：
10.1158/1535-7163.mct-17-0110
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发表时间：
2017-11
影响因子：
5.7
通讯作者：
Pommier Y
中科院分区：
文献类型：
--
作者：
Al Abo M;Sasanuma H;Liu X;Rajapakse VN;Huang SY;Kiselev E;Takeda S;Plunkett W;Pommier Y
2 '-C-氰基-2'-脱氧-1-β-D-阿拉伯呋喃戊糖基胞嘧啶（CNDAC）是抗癌药物sapacitabine的活性代谢产物。CNDAC在DNA复制过程中掺入基因组中，随后经历β-消除，产生具有异常3 '端的单链断裂。由于酪氨酰-DNA磷酸二酯酶1（TDP 1）选择性水解非磷酸化的3 '-封闭末端，我们测试了它在CNDAC诱导的DNA损伤修复中的作用。我们发现，缺乏TDP 1的细胞（禽类TDP 1 −/− DT 40细胞和人TDP 1 KO TSCER 2和HCT 116细胞）对CNDAC表现出明显的超敏反应。我们还鉴定了CNDAC DNA修复途径中的BRCA 1、FANCD 2和PCNA。比较CNDAC与化学相关的阿拉伯糖核苷类似物，阿糖胞苷（阿糖胞苷，AraC）和拓扑异构酶I抑制剂喜树碱（CPT），这两种药物都产生3 '端阻断DNA损伤，也被TDP 1修复，我们发现BRCA 2的失活使细胞对CNDAC和CPT过敏，但对AraC不敏感。相反，缺乏PARP 1的细胞仅对CPT过敏，而对CNDAC或AraC不敏感。对癌细胞系数据库（CCLE、GDSC、NCI-60）和人类癌症（TCGA）中的TDP 1表达的检查揭示了TDP 1的广泛表达，其与PARP 1表达、TDP 1基因拷贝数和启动子甲基化相关。因此，本研究确定了TDP 1作为各种癌症类型（特别是非小细胞肺癌）对CNDAC反应的新决定因素的重要性，并证明了BRCA 2，PARP 1和TDP 1在对CNDAC，AraC和CPT的细胞反应中的差异参与。
2'-C-cyano-2'-deoxy-1-β-D-arabino-pentofuranosylcytosine (CNDAC) is the active metabolite of the anticancer drug, sapacitabine. CNDAC is incorporated into the genome during DNA replication and subsequently undergoes beta-elimination that generates single-strand breaks with abnormal 3’-ends. Because tyrosyl-DNA phosphodiesterase 1 (TDP1) selectively hydrolyzes non-phosphorylated 3’-blocking ends, we tested its role in the repair of CNDAC-induced DNA damage. We show that cells lacking TDP1 (avian TDP1−/− DT40 cells and human TDP1 KO TSCER2 and HCT116 cells) exhibit marked hypersensitivity to CNDAC. We also identified BRCA1, FANCD2 and PCNA in the DNA repair pathways to CNDAC. Comparing CNDAC with the chemically related arabinosyl nucleoside analog, cytosine arabinoside (cytarabine, AraC) and the topoisomerase I inhibitor camptothecin (CPT), which both generate 3’-end blocking DNA lesions that are also repaired by TDP1, we found that inactivation of BRCA2 renders cells hypersensitive to CNDAC and CPT but not to AraC. By contrast, cells lacking PARP1 were only hypersensitive to CPT but not to CNDAC or AraC. Examination of TDP1 expression in the cancer cell line databases (CCLE, GDSC, NCI-60) and human cancers (TCGA) revealed a broad range of expression of TDP1, which was correlated with PARP1 expression, TDP1 gene copy number and promoter methylation. Thus, the present study identifies the importance of TDP1 as a novel determinant of response to CNDAC across various cancer types (especially non-small cell lung cancers), and demonstrates the differential involvement of BRCA2, PARP1 and TDP1 in the cellular responses to CNDAC, AraC and CPT.