circTNFRSF21介导miR-133调控TAGLN2在膀胱癌侵袭转移中的作用和分子机制研究

Bladder cancer is the most common malignancy of the urinary system. Currently, there is a lack of effective clinical control strategies for the high recurrence rate and high metastasis rate of postoperative bladder cancer. Circular RNA (circRNA) is a new type of non-coding RNA with stable structure and high abundance. Evidences are accumulating that circRNAs are involved in the regulation of cancer development and are potential new targets for cancer therapy. However, its role and mechanism in bladder cancer remain unclear. We previously conducted comprehensive high-throughput sequencing of bladder cancer-related circRNAs. Further results suggested that circTNFRSF21 promotes the migration and invasion of bladder cancer by up-regulating TAGLN2 through competitively binding to miR-133a-3p/miR-133b. This project intends to increase the clinical sample size, to clarify the relationship between circTNFRSF21 upregulation and pathological features and prognosis of bladder cancer; and to further clarify the regulatory mechanism of circTNFRSF21 by cell models, animal models and reporter genes, et al. The completion of this project will systematically elucidate the biological function, molecular mechanism and clinical value of circRNA in the regulation of bladder cancer recurrence and metastasis, and provide new ideas and new methods for the diagnosis and treatment of bladder cancer.

膀胱癌是泌尿系统最常见的恶性肿瘤，目前对膀胱癌术后高复发和高转移率临床仍然缺少有效的控制手段。CircRNA是共价成环且结构稳定的一类新型非编码RNA，其表达丰富并且参与肿瘤等疾病调控，是癌症治疗潜在新靶点，然而在膀胱癌中作用和机制不清。本项目前期通过高通量测序全面、系统地筛选鉴定膀胱癌相关circRNA，进一步的研究结果提示circTNFRSF21通过结合miR-133a-3p/miR-133b上调TAGLN2促进膀胱癌侵袭转移。本项目拟加大临床样本量，明确circTNFRSF21上调与膀胱癌病理特征及预后的关系；进一步通过细胞模型、动物模型、报道基因等方法，阐明circTNFRSF21的调控机制。本项目的完成将比较系统地阐明circTNFRSF21在膀胱癌复发转移调控中的生物学功能、分子机制及其临床应用价值，为膀胱癌诊断和治疗提供新思路和新方法。

CircRNA是共价成环且结构稳定的一类新型非编码RNA，与肿瘤发生发展密切相关，是癌症诊治的潜在新靶点。本项目通过环状RNA高通量测序以及细胞和临床组织验证，发现circTNFRSF21在膀胱癌显著上调。我们构建了特异性敲低circTNFRSF21的siRNA以及过表达circTNFRSF21的质粒，通过敲低和过表达从正反两方面证实circTNFRSF21能促进膀胱癌细胞增殖、迁移和侵袭，但对细胞周期和凋亡没有显著作用。转录组测序和差异表达基因KEGG富集分析发现，敲低circTNFRSF21显著富集代谢通路、钙调控通路等。进一步，我们通过RNA-FISH以及核-质分离RNA qPCR分析发现circTNFRSF21主要在胞浆富集，双荧光素酶报道基因以及RNA pull-down实验提示circTNFRSF21可能结合miR-133，rescue实验显示过表达miR-133 inhibitor能够部分逆转circTNFRSF21敲低对膀胱癌细胞迁移和侵袭的抑制；反之，过表达miR-133 mimics能够部分逆转circTNFRSF21过表达促进膀胱癌细胞的迁移侵袭的作用。总之，我们的实验结果基本证实circTNFRSF21可部分通过miR-133调控膀胱癌细胞的迁移侵袭。