The human endonuclease III enzyme is a relevant target to potentiate cisplatin cytotoxicity in Y-box-binding protein-1 overexpressing tumor cells
The human endonuclease III enzyme is a relevant target to potentiate cisplatin cytotoxicity in Y-box-binding protein-1 overexpressing tumor cells
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DOI：
10.1111/j.1349-7006.2008.00739.x
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发表时间：
2008-04-01
期刊：
影响因子：
5.7
通讯作者：
Lebel, Michel
中科院分区：
文献类型：
--
作者：
Guay, David;Garand, Chantal;Lebel, Michel
Y-box-binding protein-1（YB-1）是一种多功能蛋白，参与转录、翻译和mRNA剪接的调控。近年来，一些实验室已经证明YB-1直接参与细胞对遗传毒性应激的反应。重要的是，YB-1在对顺铂耐药的肿瘤细胞系中增加，并且YB-1的核表达水平可预测乳腺肿瘤、卵巢癌和滑膜肉瘤的耐药性和患者结局。YB-1在体外与几种DNA修复酶结合，包括人核酸内切酶III（hNTH 1）。人NTH 1是一种双功能DNA糖基化酶/脱嘌呤/脱嘧啶裂解酶，参与碱基切除修复。在这项研究中，我们表明，YB-1结合特异性的自抑制结构域的hNTH 1，提供了一种机制，YB-1刺激hNTH 1活性。实际上，YB-1在体外强烈刺激hNTH 1对含有氧化碱基的DNA双链体探针的活性，所述氧化碱基是顺铂处理的细胞中易于存在的损伤。我们还观察到在乳腺癌MCF 7细胞系中，用UV光和顺铂处理的YB-1/hNTH 1复合物形成增加。丝裂霉素C或拓扑异构酶I抑制剂喜树碱未观察到这种增加。因此，针对YB-1或hNTH 1的反义RNA增加了细胞对UV和顺铂的敏感性，但对丝裂霉素C没有增加。针对YB-1的反义RNA增加喜树碱敏感性。相反，针对hNTH 1的反义核酸则没有。最后，针对hNTH 1的siRNA在另外的顺铂抗性YB-1过表达MCF 7细胞中重新建立了细胞毒性。这些数据表明，hNTH 1是一个相关的目标，以加强顺铂的细胞毒性在YB-1过表达的肿瘤细胞。
Y-box-binding protein-1 (YB-1) is a multifunctional protein involved in the regulation of transcription, translation, and mRNA splicing. In recent years, several laboratories have demonstrated that YB-1 is directly involved in the cellular response to genotoxic stress. Importantly, YB-1 is increased in tumor cell lines resistant to cisplatin, and the level of nuclear expression of YB-1 is predictive of drug resistance and patient outcome in breast tumors, ovarian cancers, and synovial sarcomas. YB-1 binds to several DNA repair enzymes in vitro including human endonuclease III (hNTH1). Human NTH1 is a bifunctional DNA glycosylase/apurinic/apyrimidinic lyase involved in base excision repair. In this study, we show that YB-1 binds specifically to the auto-inhibitory domain of hNTH1, providing a mechanism by which YB-1 stimulates hNTH1 activity. Indeed, YB-1 strongly stimulates in vitro the activity of hNTH1 toward DNA duplex probes containing oxidized bases, lesions prone to be present in cisplatin treated cells. We also observed an increase in YB-1/hNTH1 complex formation in the mammary adenocarcinoma MCF7 cell line treated with UV light and cisplatin. Such an increase was not observed with mitomycin C or the topoisomerase I inhibitor camptothecin. Accordingly, antisense RNAs against either YB-1 or hNTH1 increased cellular sensitivity to UV and cisplatin but not to mitomycin C. An antisense RNA against YB-1 increased camptothecin sensitivity. In contrast, an antisense against hNTH1 did not. Finally, siRNA against hNTH1 re-established cytotoxicity in otherwise cisplatin-resistant YB-1 overexpressing MCF7 cells. These data indicate that hNTH1 is a relevant target to potentiate cisplatin cytotoxicity in YB-1 overexpressing tumor cells.