微小RNA-221对甲状腺癌细胞侵袭能力的影响及其机制

Effect of microRNA-221 on invasion ability of thyroid cancer cells and mechanism

目的观察甲状腺癌(TC)细胞中微小RNA-221(miR-221)对第10号染色体缺失的磷酸酶及张力蛋白同源的基因(PTEN)的调控作用,及对甲状腺癌细胞侵袭能力的影响。方法收集河北医科大学第二医院普外科2018年4月至2019年12月30例甲状腺乳头状癌组织标本。应用荧光定量聚合酶链反应(PCR)检测甲状腺癌及癌旁组织中miR-221和PTEN的表达;将miR-221模拟物(mimics)染到TPC-1细胞中,应用双荧光素酶报告基因实验观察miR-221对PTEN的调控作用;同时,将过表达PTEN质粒与miR-221 mimic共转染至TPC-1细胞,然后应用Transwell细胞侵袭实验检测miR-221和PTEN表达变化对甲状腺癌细胞侵袭能力的影响,组间比较采用t检验。结果荧光定量PCR结果显示,miR-221在甲状腺癌组织中的表达水平(4.12±0.09)明显高于癌旁组织表达水平(1.32±0.06),差异有统计学意义(t=18.320,P<0.01);并且miR-221与PTEN mRNA的表达水平呈负相关(r=-0.429,P<0.05);miR-221 mimic转染组PTEN相对荧光素酶活性(0.35±0.04)明显低于对照组(1.05±0.03,t=12.120,P<0.05),差异有统计学意义;甲状腺癌细胞转染miR-221 mimic组侵袭细胞数(352.1±37.2)明显高于对照组侵袭细胞数(189.7±23.1,t=3.135,P<0.01),差异有统计学意义;而共转染PTEN过表达质粒后,甲状腺癌侵袭细胞数(165.0±16.2)与阴性对照组(168.7±17.6)比较,差异无统计学意义(t=1.060,P>0.05)。结论miR-221能够促进甲状腺癌细胞的侵袭能力,其作用机制可能与靶向抑制PTEN的表达有关。

Objective To observe the regulatory effect of microRNA(miR)-221 on phosphatase and tensin homologue deleted on chromosome 10(PTEN)gene in thyroid cancer(TC)cells and its influence on the invasion ability of TC cells.Methods A total of 30 cases of TC papillary carcinoma tissue specimens were collected from April 2018 to December 2019 in the General Surgery Department of the Second Hospital of Hebei Medical University.The expression of miR-221 and PTEN gene was detected in TC and adjacent tissues by Real-time PCR.After transfecting miR-221 mimic into human TC cell line TPC-1,dual luciferase reporter gene assay was used to observe the regulation of miR-221 on PTEN gene.After TPC-1 cells were transfected with PTEN overexpression plasmids combined with miR-221 mimics,the effects of miR-221 and PTEN expression on the invasion of TC cells were examined by Transwell assay.T test was used for comparison between two groups.Results Real-time PCR results indicated that miR-221 expression(4.12±0.09)was significantly higher in TC tissues than that in adjacent tissues(1.32±0.06,t=18.320,P<0.01).miR-221 was negatively correlated with PTEN mRNA expression in TC(r=-0.429,P<0.05).The relative luciferase activity of PTEN in the miR-221 mimic transfection group(0.35±0.04)was significantly lower than that in the control group(1.05±0.03,t=12.120,P<0.05).Moreover,the number of invasive cells in the miR-221 mimic group(352.1±37.2)was significantly higher than that in the control group(189.7±23.1,t=3.135,P<0.01).In addition,after co-transfection with PTEN overexpression plasmids,compared with the negative control group(168.7±17.6),the number of invasive cells in TC(165.0±16.2)had no significant difference(t=1.060,P>0.05).Conclusion MiR-221 can promote the invasion ability of TC cells,and its mechanism may be related to the targeted inhibition of PTEN expression.