miR-9通过Wnt/β-catenin信号通路调控甲状腺癌细胞侵袭和迁移的机制研究

Effects of miR-9 on the invasion and migration of thyroid cancer cells and its regulatory effects on Wnt/β-catenin signaling pathway

目的探讨miR-9对甲状腺癌细胞侵袭和迁移影响及对Wnt/β-catenin信号通路的调控作用。方法采用实时荧光定量PCR(Real-time PCR)检测miR-9在正常甲状腺上皮细胞系Nthyori3-1和人甲状腺癌细胞系TPC-1、MDA-T32及SW579中的表达情况,采用脂质体转染技术将miR-9 mimics及mimics control转染至甲状腺癌TPC-1细胞,Real-time PCR检测miR-9的表达水平,Transwell和划痕实验检测过表达miR-9对TPC-1细胞侵袭和迁移能力的影响,蛋白免疫印迹(Western blot)法检测侵袭和迁移相关蛋白MMP-2和MMP-9及Wnt/β-catenin信号通路中β-catenin和下游分子c-Myc的表达。结果与正常甲状腺上皮细胞Nthyori3-1比,甲状腺癌细胞系(TPC-1、MDA-T32和SW579)中miR-9的表达水平显著下调(P<0.05)。转染miR-9 mimics后TPC-1细胞中miR-9的表达水平明显升高(P<0.05)。过表达miR-9后侵袭细胞数明显减少,细胞迁移率明显降低,TPC-1细胞中MMP-2、MMP-9、β-catenin和c-Myc的表达均显著下调,差异均有统计学意义(P<0.05)。结论miR-9可通过抑制Wnt/β-catenin信号通路的激活减弱甲状腺癌TPC-1细胞侵袭和迁移能力。

Objective To investigate the effects of miR-9 on the invasion and migration of thyroid cancer cells and its regulatory effects on Wnt/β-catenin signaling pathway.Methods Real-time PCR was used to detect the expression levels of miR-9 in normal thyroid epithelial cell line Nthyori3-1 and human thyroid cancer cell lines TPC-1,MDA-T32 and SW579.The lipidosome transfection technique was used to transfected miR-9 mimics and mimics control into thyroid carcinoma TPC-1 cells.Real-time PCR was used to detect the expression levels of miR-9,and the Transwell and scratch assays were used to examine the effects of miR-9 overexpression on TPC-1 cell invasion and migration.In addition Western Blot was used to detect the expressions ofβ-catenin and downstream c-Myc in the invasion and migration related proteins MMP-2 and MMP-9 and Wnt/β-catenin signaling pathways.Results As compared with those in normal thyroid epithelial cells Nthyori3-1,the expression levels of miR-9 in thyroid cancer cell lines(TPC-1,MDA-T32 and SW579)were significantly down-regulated(P<0.05),however,the expression levels of miR-9 in TPC-1 cells were significantly increased after transfection of miR-9 mimics(P<0.05).After overexpression of miR-9,the number of invasive cells and cell migration rate were significantly decreased,and the expression levels of MMP-2,MMP-9,β-catenin and c-Myc were significantly down-regulated in TPC-1 cells(P<0.05).Conclusion The miR-9 can attenuate the invasion and migration abilities of thyroid carcinoma TPC-1 cells by inhibiting the activation of Wnt/β-catenin signaling pathway.