lncRNA PVT1作为ceRNA调控VEGF-C在膀胱癌淋巴转移中的作用机制研究

内源性竞争性RNA(ceRNA)学说认为ceRNA能竞争性结合miRNAs从而调节miRNAs靶基因表达。申请人前国家自然科学基金课题研究提示VEGF-C高表达可促进膀胱癌淋巴转移，且miR-128可通过抑制VEGF-C表达进而抑制膀胱癌淋巴转移。通过基因芯片筛选与生物信息学分析我们发现lncRNA PVT1与VEGF-C可能互为ceRNA，二者竞争miR-128。预实验表明PVT1和miR-128在膀胱组织中表达呈负相关，PVT1和VEGF-C表达呈正相关，提示 PVT1可作为ceRNA竞争miR-128，减少miR-128对VEGF-C的抑制作用，从而促进膀胱癌淋巴转移。本课题拟采用lncRNA过表达及稳定剔除技术、荧光素酶实验、基因定点突变、RIP实验和小鼠体内成瘤实验等方法，从体内体外同时验证和阐明PVT1作为ceRNA调控VEGF-C网络的作用机制，为膀胱癌治疗提供新的靶点。

According to "competitive endogenous RNAs (ceRNAs)" theory, ceRNAs communicate with and co-regulate each other by competing for binding to shared microRNAs. Our previous studies have confirmed that VEGF-C overexpression was associated with lymphatic metastasis in bladder cancer, miR-128 could play a role in bladder cancer tumourigenesis by targeting VEGF-C. Microarray screening and bioinformatics analysis suggest that lncRNA PVT1 may act as ceRNAs by competing with the parental VEGF-C mRNA for miRNA128 binding. Our previous experiments have shown a negative correlation between the expression level of VEGF-C and miR-128, a positive correlation between PVT1 and VEGF-C. These results suggest that PVT1 may competing for miR-128 and reduce the inhibitory effect of miR-128 on the VEGF-C, so as to promote lymphatic metastasis of bladder carcinoma. This study is going to further verify and clarify the mechanism that lncRNA PVT1 and VEGF-C functions as ceRNAs by competing for miR-128 in bladder cancer. We will use the lncRNA overexpression and suppression technology, Luciferase assays, site-directed mutation, RNA immunoprecipitation, and research the role of PVT1. Provide a new treatment strategy for inhibition of lymph metastasis of bladder cancer.