METTL3/YTHDF2 m6A轴介导的circ-DNMT3b的竞争性表达调控及其在膀胱 癌顺铂耐药中的机制研究

膀胱癌是我国最常见的泌尿系统恶性肿瘤，顺铂为主的化疗耐药严重影响肌层浸润性与转移性膀胱癌的治疗效果。已有证据显示，circRNA和甲基化修饰N-6-甲基化-腺苷酸（m6A）参与调控肿瘤发生发展与化疗耐药。而上述两者在膀胱癌顺铂耐药中的作用及其机制并不清楚。项目组前期对circRNA和miRNA测序结果及两者关联性进行分析，筛选出膀胱癌顺铂耐药相关circ-DNMT3b及其靶点miRNAs，并初步发现circ-DNMT3b表达受到m6A调控。本项目拟在此基础上，利用MeRIP、RIP等技术进一步明确上游m6A在circ-DNMT3b竞争性表达调控中的作用；同时利用FISH、RNA pull down等技术揭示circ-DNMT3b介导的下游顺铂耐药信号通路，从而系统阐明m6A/circ-DNMT3b/miRNAs在顺铂耐药中的功能和分子机制，为建立顺铂耐药性膀胱癌诊断和治疗新方法打下基础。

Bladder cancer (BCa) is the most common urological cancer in China. Due to the arising of cisplatin resistance, it presents reductions of therapeutic effects especially for the muscle-invasive and metastatic BCa. Nowadays, circRNA and RNA N6-methyladenosine methylation (m6A) modification are found to be involved in carcinogenesis, tumor progression and chemo-resistance. However, the specific mechanism of m6A and circRNA in cisplatin-resistant BCa still remains elusive. In previous study, we identified circ-DNMT3b and potential target miRNAs according to the sequencing of circRNA and miRNAs in a successfully-induced cisplatin-resistant BCa cell line, and found that circ-DNMT3b expression was regulated by m6A. In this study, MeRIP and RIP etc.methods are aimed to be utilized to explore how the upstream m6A regulates the competitive expression of circ-DNMT3b. Meanwhile, RNA FISH and RNA pull down etc.methods will also be used to further investigate the downstream cisplatin-resistant associated pathway induced by circ-DNMT3b. To conclude, this study will uncover the function and regulatory mechanisms of m6A/circ-DNMT3b/miRNAs in cisplatin-resistant BCa.