circRIP2 accelerates bladder cancer progression via miR-1305/Tgf-β2/smad3 pathway
circRIP2 accelerates bladder cancer progression via miR-1305/Tgf-β2/smad3 pathway
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DOI：
10.1186/s12943-019-1129-5
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发表时间：
2020-02-04
期刊：
影响因子：
37.3
通讯作者：
Lin, Tianxin
中科院分区：
文献类型：
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作者：
Su, Yinjie;Feng, Weilian;Lin, Tianxin
背景越来越多的证据表明环状RNA在膀胱癌的发生发展过程中起着重要的调控作用。然而，环状RNA在膀胱癌中的表达模式和作用仍然很少研究。方法采用RNA测序和qPCR技术鉴定和评价circRIP 2的功能;采用CCK 8、克隆形成、伤口愈合和transwell实验检测circRIP 2的体外作用;设计小鼠皮下肿瘤模型进行体内研究。Western blot、RNA pulldown分析、miRNA捕获和双荧光素酶评估用于机制研究。结果circRIP 2在膀胱癌组织中是一种保守的环状RNA，在膀胱癌组织中被抑制。circRIP 2高表达与膀胱癌的分级、分期、转移及预后呈负相关。体外和体内研究表明，circRIP 2能够通过诱导EMT促进膀胱癌进展。关于其机制，我们进行了RNA测序分析，RNA下拉与生物素标记的circRIP 2特异性探针，双荧光素酶报告基因测定。发现circRIP 2能够海绵化miR-1305以升高膀胱癌中的Tgf-β 2，并通过Tgf-β 2/smad 3途径诱导EMT。阻断膀胱癌中的Tgf-β 2剥夺了circRIP 2诱导的癌症进展和EMT。结论本研究首次证明circRIP 2在膀胱癌中的表达差异，并与膀胱癌的进展呈负沿着变化;有效的circRIP 2活性通过激活miR-1305/Tgf-beta 2/smad 3通路诱导EMT而加速膀胱癌的进展。该研究表明，circRIP 2可能是膀胱癌患者的潜在生物标志物和治疗靶点。
Background Increasing evidences indicate that circular RNAs exert critical function in regulating bladder cancer progression. However, the expressive patterns and roles of circular RNAs in bladder cancer remain less investigated. Methods circRIP2 was identified and evaluated by RNA-sequencing and qPCR; in vitro effects of circRIP2 were determined by CCK8, clone forming, wound healing and trans-well assays; while mice subcutaneous tumor model was designed for in vivo analysis. Western blot, RNA pulldown assay, miRNA capture and dual luciferase assessment were applied for mechanistic studies. Results circRIP2 was identified as a conserved and dramatically repressed circular RNA in bladder cancer. Patients that displayed higher circRIP2 expression negatively associate with the grade, stage, metastasis as well as outcome of bladder cancer. In vitro and in vivo studies suggest that circRIP2 enables to promote bladder cancer progression via inducing EMT. Regarding the mechanism, we performed RNA-sequencing analysis, RNA pulldown with biotin-labeled circRIP2-specific probe, dual luciferase reporter assay. It was found that circRIP2 enables to sponge miR-1305 to elevate Tgf-beta 2 in bladder cancer, and inducing EMT via Tgf-beta 2/smad3 pathway. Blocking Tgf-beta 2 in bladder cancer deprives circRIP2 induced cancer progression and EMT. Conclusions Taken together, our study provides the first evidence that circRIP2 expresses differentially in bladder cancer and negatively along with the cancer progression; effective circRIP2 activity accelerates bladder cancer progression via inducing EMT by activating miR-1305/Tgf-beta 2/smad3 pathway. The research implies that circRIP2 might be a potential biomarker and therapeutic target for bladder cancer patients.