NF-κB对人结肠癌细胞上皮间质转化及侵袭转移的影响

Role of NF-κB in induction of epithelial-mesenchymal transition, migration and invasion of human colon cancer cells

目的:研究核转录因子-κB(nuclear factorkappa B,NF-κB)对人结肠癌细胞上皮间质转化(epithelial-mesenchymal transition,EMT)及侵袭和转移的影响.方法:将人结肠癌HCT116细胞分为NF-κB激活组,抑制组和空白对照组.分别用NF-κB活化激活剂肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α),终浓度为20 ng/mL,NF-κB活化抑制剂吡咯烷二硫代甲酸铵(ammonium pyrrolidinedithiocarbamate,PDTC),终浓度为20μmol/L干预HCT116细胞4 d.采用相差显微镜观察细胞形态变化,Transwell小室模型观察细胞侵袭迁移能力变化,Western blot检测p65、P-p65、E-cadherin和N-cadherin的蛋白表达,QT-PCR检测E-cadherin和N-cadherin的mRNA表达.结果:TNF-α可上调P-p65和N-cadherin的表达,抑制E-cadherin的表达,同时明显促进HCT116细胞的EMT形态发生(如细长丝状伪足和纺锤状细胞形成),并使侵袭和迁移能力增强;相反,PDTC则降低P-p65和N-cadherin的表达,而增加E-cadherin的表达,且抑制细胞的EMT形态发生(如伪足不明显,细胞成多角形并紧密排列)及减弱细胞的侵袭迁移能力.对照组、TNF-α组及PDTC组的侵袭细胞数(97.75±3.77 vs 118.50±1.95,51.00±1.83);迁移细胞数(140.00±4.32 vs 167.00±6.36,80.00±2.53);N-cadherin mRNA的表达(1.00±0.00 vs 3.90±0.47,0.08±0.02);E-cadherin mRNA的表达(1.00±0.00 vs0.26±0.08,6.03±0.59,均P<0.05).结论:NF-κB可以促进结肠癌HCT116细胞的EMT发生、侵袭和转移.

AIM： To investigate the role of nuclear factorkappa B（NF-κB） in the induction of epithelialmesenchymal transition（EMT）,migration and invasion of human colon cancer cell line HCT116.METHODS： HCT116 cells were divided into three groups and treated with 20 ng/mL of tumor necrosis factor-α（TNF-α）（NF-κB activation group）,20 μmol/L of ammonium pyrrolidinedithiocar-bamate（PDTC）（NF-κB suppression group）,and equal volume of culture medium（control group）,respectively.Four days later,cell morphological changes associated with EMT were observed under a phase contrast microscope,and the migration ability and invasiveness were assessed by Transwell chamber assays.The protein expression of p65,P-p65,E-cadherin and N-cadherin was analyzed by Western blot,and the mRNA expression of E-cadherin and N-cadherin was detected by quantitative real-time PCR.RESULTS： TNF-α up-regulated the expression of P-p65 and N-cadherin,suppressed the expression of E-cadherin,and caused a complete EMTphenotype,which manifested as the formation of large filopodia-like processes and spindle-cell shape.Also,TNF-α promoted cell invasion and migration.In contrast,PDTC down-regulated the expression of P-p65 and N-cadherin,upregulated the expression of E-cadherin,inhibited the occurrence of typical EMT phenomenon,and suppressed cell invasion and migration.Compared with the control group,TNF-α group and PDTC group showed significantly different cell invasion（97.75 ± 3.77 vs 118.50 ± 1.95,51.00 ± 1.83,P〈0.05 for both）,cell migration（140.00 ± 4.32 vs 167.00 ± 6.36,80.00 ± 2.53,P〈0.05 for both）,and mRNA expression of N-cadherin（1.00 ± 0.00 vs 3.90 ± 0.47,0.08 ± 0.02,P〈0.05 for both） and E-cadherin（1.00 ± 0.00 vs 0.26 ± 0.08,6.03 ± 0.59,P〈0.05 for both）.CONCLUSION： NF-κB induces the occurrence of typical EMT phenomenon and promotes cell invasion and migration in human colon cancer cell line HCT116.