肿瘤干细胞DNA损伤应答增强,是肿瘤耐药的重要因素；而如何逆转耐药，有赖于深入解析肿瘤干细胞DNA损伤应答特性。基于关键干性基因参与正常干细胞DNA损伤应答的最新进展以及我们前期首次发现Nanog可能作为膀胱癌干细胞新型标志分子促进顺铂诱导DNA损伤应答的研究线索，本项目将首次探讨Nanog在肿瘤干细胞耐药中的作用。本研究将采取Nanog特异启动子驱动GFP策略，分离、鉴定高表达Nanog细胞膀胱癌肿瘤干细胞特性；利用慢病毒系统， 建立外源Nanog 基因干预膀胱癌肿瘤干细胞， 联合细胞学和动物模型，证实Nanog通过促进组蛋白乙酰化和染色质重塑，参与DNA修复蛋白募集，进而促进顺铂诱导的DNA修复的作用与机制。本研究有望建立基于Nanog+标志膀胱癌干细胞分离、鉴定新方法；不仅从全新角度探讨干性基因在肿瘤干细胞中的关键作用，同时抑制Nanog协同顺铂为治疗膀胱肿瘤提供可能的新策略。

Cisplatin is a DNA damage reagent used in cancer therapy, which can cause DNA interstrand and intrastrand crosslink. Being a typical character, cisplatin resistance or drug resistance is linked to enhanced DNA damage response in cancer stem cells. Based on our previous finding, we were the first to discover that Nanog may act as a specific molecular marker of bladder cancer stem cells and have a role in the cisplatin resistance. In this project, to explore the special mechanism of DNA damage response in bladder cancer stem cells, we will further make an effort to investigate potential role and mechanism of stemness gene "Nanog" in the cisplatin resistance. With the strategy of Nanog promoter-GFP, we will try to identify bladder cancer stem cells based on Nanog+ cells isolation. Furthermore, with the lentivirus system, we will establish the Nanog overexpressed- bladder cancer stem cells and shRNA-Nanog-bladder cancer stem cells. Combined the studies of molecular cell biology and nude animal models, we will aim to prove that Nanog can enhance the cisplatin resistance, via promoting the chromatin accessibility, histone acetylation and recruitment of certain DNA repair protein(s) to the DNA lesion site. In this studies, we aim to provide the potential novel cancer therapeutic strategy with the combination of nanog inhibition and cisplatin, and establish a novel isolation method of bladder cancer stem cells based on Nanog marker.