MicroRNA-203靶向调控Bmi-1对甲状腺乳头状癌增殖及侵袭的影响

Effect of microRNA-203 targeting regulation of Bmi-1 on proliferation and invasion of papillary thyroid cancer

目的探讨Bmi-1基因在甲状腺乳头状癌(papillary thyroid cancer,PTC)中的表达情况,并分析微小RNAs(MicroRNAs,miRNAs)靶向调控Bmi-1对PTC增殖及侵袭的影响及机制。方法收集2018年6月到2018年12月在浙江大学医学院附属杭州市第一人民医院肿瘤外科行甲状腺手术的组织标本,共计60例,通过实时定量聚合酶链反应(real-time quantitative polymerase chain reaction,RT-PCR)检测PTC组织中Bmi-1基因的表达水平并分析其与病理特征的关系。通过生物信息学网站targetscan和microRNA.org预测调节Bmi-l的miRNAs,并用荧光素酶报告基因实验进行确认。应用CCK-8(cell counting Kit-8)试剂盒、Transwell小室测定PTC增殖能力、侵袭能力的改变。结果本研究发现Bmi-1基因表达与PTC病灶大小、侵袭能力呈正相关。生物信息学预测结果提示Bmi-1是微小RNA-203(MicroRNA-203,miR-203)的靶基因,miR-203针对Bmi-l的3’-UTR靶序列为GUAAAGU。转染miR-203模拟物后,PTC细胞系TPC-1中Bmi-1 mRNA表达显着下调。双荧光素酶报告基因实验证明miR-203可作用于Bmi-1基因的3’UTR区预测靶位。此外,miR-203模拟物转染后有效抑制了PTC细胞的增殖及侵袭,而在转染miR-203模拟物的PTC细胞TPC-1中同时过表达Bmi-1后可恢复PTC细胞TPC-1的增殖、侵袭能力。结论Bmi-1与PTC增殖侵袭能力正相关,miR-203可通过直接靶向Bmi-1基因来抑制PTC细胞的增殖、侵袭能力。

Objective To investigate the expression of mBmi-1 in papillary thyroid cancer(PTC)and to analyze its relationship with clinical features of PTC and its mechanism.Methons A total of 60 tissue samples were collected from Jun.2018 to Dec.2018 in Department of Oncology Surgery of Affiliated Hangzhou First People’s Hospital,Zhejiang University School of Medicine.Real-time quantitative polymerase chain reaction(RT-PCR)was used to detect the expression level of B cell-specific MLV integration site-1(mBmi-1)in PTC tissues and its relationship with pathological features was analyzed.Bmi-l microRNAs(miRNAs)were predicted by bioinformatics sites targetscan and microRNA.org and confirmed by luciferase reporter gene experiments.CCK-8(Cell Counting Kit-8)kit and Transwell chamber were used to measure changes in PTC proliferative capacity and invasive ability.Results In this study,we found that mBmi-1 expression was positively correlated with PTC lesion size and invasion ability.Bioinformatics prediction results suggested that Bmi-1 was a target gene of microRNA-203(MicroRNA-203,miR-203),and the 3’-UTR target sequence of miR-203 against Bmi-1 was GUAAAGU.After transfection of the miR-203 mimetic,the expression of Bmi-1 mRNA in the PTC cell line TPC-1 was significantly down-regulated.The dual luciferase reporter gene assay demonstrated that miR-203 can act on the 3’UTR region of the Bmi-1 gene to predict the target.In addition,the transfection of miR-203 mimetic effectively inhibited the proliferation and invasion of PTC cells,and the ability of proliferation and invasion of PTC cell TPC-1 was restored after overexpression of Bmi-1 in PTC cell TPC-1 transfected with miR-203 mimic.Conclusions Bmi-1 is positively correlated with the proliferation and invasion ability of PTC.miR-203 can inhibit the proliferation and invasion of PTC cells by directly targeting Bmi-1 gene.