miR-1/miR-143调控长链基因间非编码RNA TUG1抑制膀胱癌进展的机制研究

Non-coding RNAs are aberrantly expressed in bladder cancer. Our previous study has indicated that miR-1 and miR-143 are down-regulated, whereas lincRNA TUG1 is up-regulated in bladder cancer with higher abundance in higher grade/stage cases, and down-regulation of TUG1 decreases bladder cancer cell proliferation. Our preliminary experiment has proved that transfection of miR-1 or miR-143 mimics decrease TUG1 expression in bladder cancer cells. Bio-informatic assay reveals that there exist multiple predictable binding sites for miR-1 and miR-143 on TUG1 RNA. We hypothesize that miR-1 and miR-143 might play tumor suppressive roles via down-regulation of TUG1 in bladder cancer. This project will focus on: analyses of the relevance of expression levels between TUG1 and miR-1/miR-143; examination of the relevance between expression levels of TUG1/miR-1/miR-143 and clinicopathological features; identification of the impacts of TUG1/miR-1/miR-143 expression levels on bladder cancer cell proliferation, apoptosis, invasiveness, metastasis, cell cycle change and epithelial-mesenchymal transition in bladder cancer cells and nude mice; examination the regulated genes and pathways after over/down-regulation of TUG1; analyses the binding sites between TUG1 and miR-1/miR-143. The mechanism that miR-1 and miR-143 suppress the progression of bladder cancer via down-regulation of TUG1 will be demonstrated.Also potential novel biomarkers and therapeutic targets for bladder cancer will be investigated.

膀胱癌中非编码RNA有异常表达。我们前期研究发现miR-1和miR-143在膀胱癌低表达，长链基因间非编码TUG1在膀胱癌高表达且在高分级、分期表达丰度更高，敲低TUG1抑制膀胱癌细胞增殖。预实验转染miR-1或miR-143模拟物降低膀胱癌细胞TUG1表达。生物信息学分析示TUG1有多个miR-1和miR-143结合位点。我们推测miR-1和miR-143通过调控TUG1发挥抑癌作用。本研究拟检测膀胱癌TUG1、miR-1和miR-143表达，分析各指标表达相关性及与临床病理关系；在细胞、裸鼠成瘤模型中研究TUG1、miR-1和miR-143在膀胱癌增殖、凋亡、侵袭、转移、细胞周期变化和上皮向间充质转化中的作用；过表达和敲低TUG1检测其调控基因和通路；验证miR-1和miR-143 与TUG1结合靶点；进而阐明miR-1/miR-143调控TUG1机制,探讨潜在的膀胱癌诊疗新靶点。

膀胱癌有多种遗传和表型特征。近几年来非编码 RNA (non-coding RNA, ncRNA)在膀胱癌中的作用日益受到重视，是有潜力的预测、诊断和治疗膀胱癌新的分子靶点。我们研究证实，miR-1 和 miR-143 在膀胱癌组织中表达下调。miR-1 和 miR-143模拟物抑制膀胱癌细胞增殖与迁移，增加膀胱癌细胞凋亡。长链基因间非编码RNA TUG1 在膀胱癌高表达，敲低TUG1抑制膀胱癌细胞增殖与迁移，增加膀胱癌细胞凋亡。过表达miR-1 或miR-143以及敲低TUG1 均抑制裸鼠的膀胱癌成瘤。生物学信息分析预测miR-1和miR-143与长链基因间非编码TUG1结合位点。miR-1和miR-143 模拟物均降低膀胱癌细胞中TUG1表达。双荧光素酶报告基因系统检测提示TUG1是miR-1 和 miR-143的靶基因。表达谱芯片检测发现膀胱癌细胞中敲低TUG1后一系列细胞增殖相关基因表达改变。其中敲低TUG1后SMC2明显表达降低。SMC2在膀胱癌中的表达明显高于癌旁组织。敲低SMC2抑制膀胱癌细胞增殖，促进膀胱癌细胞凋亡，并抑制裸鼠的膀胱癌成瘤，提示TUG1通过调控SMC2表达发挥促癌作用。