TET1基因对肺癌细胞迁移和侵袭能力的影响

Effect of TET1 gene expression on migration and invasion in lung cancer cells

目的探讨TET1基因表达水平对肺癌细胞迁移和侵袭能力的影响及其作用机制。方法采用RT-qPCR检测正常支气管上皮细胞及肺癌细胞株中TET1基因的表达水平;通过构建TET1基因过表达和敲低表达肺癌细胞模型,采用划痕愈合实验和Transwell实验分析TET1基因不同表达水平对肺癌细胞迁移及侵袭能力的影响;通过RT-qPCR和蛋白印迹法对TET1下游调控基因β-catenin(CTNNB1)、MMP7的mRNA及蛋白表达水平进行检测并确定其可能的信号通路。结果多种肺癌细胞中TET1基因表达水平较之正常支气管上皮细胞(human bronchial epithelial,HBE)均呈现显著下降(P<0.01)。过表达TET1基因可明显抑制肺癌细胞迁移和侵袭能力,而敲低TET1基因表达水平后肺癌细胞侵袭及迁移能力明显增强(P<0.01);mRNA及蛋白表达水平检测发现,过表达TET1基因后其下游基因CTNNB1、MMP7的表达水平明显下降(P<0.01),而敲低TET1基因表达后其下游基因CTNNB1、MMP7的表达水平显著上升(P<0.01)。β-catenin信号通路抑制剂处理可显著降低TET1对肺癌细胞迁移和侵袭的作用。结论 TET1基因表达在多种肺癌细胞株中显著下降。TET1基因可能通过Wnt/β-catenin信号通路及其关键基因CTNNB1、MMP7的表达水平抑制肺癌细胞的迁移及侵袭。

Objective To explore the effect of ten-eleven translocation family 1(TET1)gene expression on the migration and invasion of lung cancer cells and investigate its underlying mechanism.Methods The expression level of TET1 gene in normal human bronchial epithelial(HBE)cells and lung cancer cell lines(H460,H358,95D and LTEP-a-2)was detected by quantitative RT-PCR.The effects of different expression level(overexpression and knockdown)of TET1 gene on the migration and invasion ability in lung cancer cells was analyzed by wound healing experiment and Transwell assay.The mRNA and protein expression levels of downstream regulatory gene β-catenin(CTNNB1)and MMP7 were detected by quantitative RT-PCR and Western blotting to determine the possible signal pathway.Results The expression level of TET1 gene was decreased in lung cancer cells compared with normal HBE cells(P<0.01).Overexpression of TET1 gene significantly inhibited the migration and invasion of lung cancer cells,while its knockdown enhanced the invasion and migration abilities of lung cancer cells(P<0.01).The mRNA and protein expression levels of CTNNB1 and MMP7 were decreased after TET1 overexpression,while the mRNA and protein levels of the 2 molecules were increased after knockdown(P<0.01).Blockade of CTNNB1 by its inhibitor significantly diminished the effect of TET1 on the migration and invasion of lung cancer cell lines.Conclusion The expression level of TET1 is down-regulated in lung cancer cell lines.TET1 gene may inhibit the migration and invasion of lung cancer cells mainly through Wnt/β-catenin signaling pathway and its key downstream genes CTNNB1 and MMP7.