JC多瘤病毒感染及其非编码调控区突变参与膀胱癌发生发展的作用及机制研究

JC polyomavirus (JCV) encodes the oncogenic protein large T-antigen (LTag), and its latent infection in urinary bladder epithelium is an important risk factor for bladder cancer. Our prior preliminary work showed that the bladder cancer patients had elevated levels of JCV titer in tumor tissues and voided urine, with mutations in viral non-coding control region (NCCR) which locates in the upstream of LTag gene and directly regulates LTag expression. However, the role and mechanism of JCV infection and its NCCR mutations in bladder cancer development still remain elusive. Combination of the applicant's previous research in virology (Ou et al., J Gen Virol 2015; Virus Res 2014, 2015), the project will be conducted as following: 1) Comparison of JCV infection in bladder cancer patients and normal populations and analysis of NCCR tumor specificity will be performed to confirm the association between bladder cancer and JCV infection as well as its NCCR mutaions; 2) The reporter gene expression system which be regulated by JCV NCCR will be established to reveal the effects of NCCR mutations on its transcriptional regulation function; 3) In vitro cell function experiment and in vivo tumorigenesis experiment will be carried out to further study the effect of NCCR mutations on the tumorigenic ability of transform cells and clarify the molecular mechanism of NCCR mutations regulating LTag expression to promote bladder tumor development. This project will shed new light on understanding the pathogenesis of bladder cancer and provide important theoretical and clinical basis for the carcinogenicity of JCV.

JC多瘤病毒（JCV）可编码致癌蛋白大T抗原（LTag），原发感染后常潜伏于尿路上皮组织，是膀胱癌的一个重要危险因素。我们前期研究表明膀胱癌患者癌组织与尿液JCV含量高，且病毒非编码调控区（NCCR；位于LTag上游，直接调控LTag表达）存在明显突变，但JCV感染及其NCCR突变在膀胱癌中的作用与机制仍不明确。结合申请者前期病毒学研究基础（第一作者J Gen Virol 1篇、Virus Res 2篇），本项目拟：1）比较JCV在膀胱癌患者与正常人群中感染差异，解析NCCR肿瘤特异性，进而明确JCV感染及其NCCR突变与膀胱癌的关联；2）利用报告基因表达系统，揭示突变对NCCR转录调控功能的影响；3）建立细胞与小鼠模型，深入研究NCCR突变对细胞成瘤影响，阐明其调控LTag促进膀胱肿瘤发生发展的分子机制。本研究有助于进一步认识膀胱癌发病机理，同时可为JCV致癌研究提供重要临床与理论依据。

膀胱癌发生发展的分子机理有待进一步深入研究。JC多瘤病毒（JCV）可编码致癌蛋白大T抗原（LTag），原发感染后常潜伏于尿路上皮组织，是膀胱癌的一个重要危险因素。该项目分析了健康人群与膀胱癌患者的JCV感染情况，鉴定了JCV肿瘤特异性非编码调控区（NCCR）序列特征，并解析了突变序列的调控作用与分子机制，同时开发JCV快速检测与NCCR分型的诊断方法，辅助膀胱癌筛查。此外，围绕膀胱癌的分子机理，项目通过队列研究与生物学功能研究：1）鉴定了膀胱癌中频发FRS2基因扩增且关联不良预后，细胞功能实验证实FRS2介导上皮-间质转化，促进膀胱癌侵袭转移，药理实验表明FRS2扩增的膀胱癌细胞对FGFR抑制剂敏感，揭示该标志物可用于预后评估及厄达替尼用药伴随诊断，同时研发了FRS2扩增FISH检测的方法，并申请国家发明专利；2) 鉴定了膀胱癌预后相关的9个甲基化位点与分子分型谱，可进一步对膀胱癌预后进行管理；3）解析了热休克蛋白HSP47激活ERK通路和诱导CCL2表达从而调控膀胱癌血管新生的分子机制，进一步揭示了膀胱癌血管形成的机理，同时也有望为膀胱癌靶向血管治疗提供新思路；4） 揭示膀胱癌中PLK4的抑制，可激活p38/p53/p21信号通路将肿瘤细胞生长阻滞于G1期，从而抑制膀胱肿瘤的生长，有望为膀胱癌的临床治疗提供新靶点。