微小RNA-122通过调控沉默信息调节因子1的表达抑制甲状腺乳头状癌细胞的增殖

MicroRNA-92b suppresses proliferation of papillary thyroid cancer cells by regulating ilent information regulator 1 gene expression

目的探讨甲状腺乳头状癌(PTC)细胞中微小RNA(miRNA,miR)-122对组蛋白脱乙酰酶沉默信息调节因子1(SIRT1)基因的调控作用,及对甲状腺乳头状癌细胞增殖能力的影响.方法实时定量聚合酶链反应(Real-time PCR)观察甲状腺乳头状癌及癌旁组织中miR-122的表达并分析其与SIRT1表达的相关性.将miR-122 mimics转染人甲状腺乳头状癌细胞TPC-1后,应用双荧光素酶报告基因实验观察miR-122对SIRT1基因的调控作用;应用细胞计数试剂盒(CCK-8)实验观察miR-122对甲状腺癌细胞增殖的影响.同时,将过表达SIRT1质粒共转染至TPC-1细胞,然后应用CCK-8法检测miR-122和SIRT1表达变化对甲状腺乳头状癌细胞增殖能力的影响.应用GraphPad Prism 7.0统计软件分析,相关性分析采用Spearman等级相关分析,两样本均数间的比较采用Student't检验.结果在人甲状腺乳头状癌组织中miR-122的表达水平(1.20±0.15)明显低于癌旁组织(3.06±0.26),差异有统计学意义(t=5.972,P<0.01).相关性分析结果表明miR-122与SIRT1 mRNA的表达呈负相关(r=-0.621,P<0.01).miR-122 mimics转染组SIRT1相对荧光素酶活性与对照组比较明显降低,差异有统计学意义(t=17.730,P<0.01).miR-122 mimics组细胞增殖能力较对照组显著降低,差异有统计学意义(t=3.991,P<0.01).而共转染SIRT1过表达质粒后,miR-122 mimics对甲状腺乳头状癌细胞的增殖能力的抑制出现逆转.结论miR-122可抑制甲状腺乳头状癌细胞的增殖能力,其作用机制可能与靶向抑制SIRT1的表达有关.

Objective To investigate the regulating effects of microRNA(miRNA,miR)-122 on the expression of ilent information regulator 1(SIRT1),and the proliferation abilities of papillary thyroid cancer cells.Methods Real-time quantitative polymerase chain reaction(Real-time PCR)was used to observe the expression of miR-122 in papillary thyroid carcinoma and adjacent tissues and to analyze its correlation with SIRT1 expression.After transfecting miR-122 mimics into human papillary thyroid carcinoma cell line TPC-1,the dual luciferase reporter gene assay was used to observe the regulation of miR-122 on SIRT1 gene.The effect of miR-122 on the proliferation of thyroid cancer cells was observed by CCK-8 assay.At the same time,the overexpressed SIRT1 plasmid was co-transfected into TPC-1 cells,and then the effect of miR-122 and SIRT1 expression on the proliferation of papillary thyroid carcinoma cells was detected by CCK-8 assay.Analysis was performed using GraphPad Prism 7.0 statistical software.Correlation analysis was performed using Spearman rank correlation analysis.Student's t test was used to compare the two sample means.Results Compared with adjacent tissues(1.20±0.15),the expression level of miR-122(3.06±0.26)in papillary thyroid carcinoma was significantly down-regulated,and the difference was statistically significant(t=5.972,P<0.01).Correlation analysis showed that miR-122 was negatively correlated with SIRT1 mRNA expression(r=-0.621,P<0.01).The relative luciferase activity of SIRT1 in miR-122 mimics transfection group was significantly lower than that in the control group,and the difference was statistically significant(t=17.730,P<0.01).The cell proliferation ability of miR-122 mimics group was significantly lower than that of the control group,and the difference was statistically significant(t=3.991,P<0.01).After co-transfection of the SIRT1 overexpression plasmid,the inhibition of the proliferation of thyroid papillary carcinoma cells by miR-122 mimics was reversed.Conclusion miR-122 can inhibit the proliferation of papillary thyroid cancer cells,and its mechanism may be related to the targeted inhibition of SIRT1 expression.