核受体Nur77对肝癌细胞迁移和侵袭的影响

Effect of nuclear receptor Nur77 on migration and invasion of hepatocellular carcinoma cells

目的探讨核受体Nur77对人肝癌细胞迁移和侵袭能力的影响。方法采用蛋白免疫印迹法检测人正常肝细胞L02及肝癌细胞株SMMC-7721、Bel-7402、Hep3B、SK-Hep1和HepG2的Nur77蛋白基础表达水平。根据不同细胞株Nur77蛋白的表达情况,采用蛋白免疫印迹法分别验证应用siRNA沉默SMMC-7721和Hep3B细胞及过表达质粒转染HepG2细胞48h后Nur77蛋白表达水平。并利用Transwell小室探讨沉默或过表达Nur77对肝癌细胞迁移、侵袭的影响。结果蛋白免疫印迹结果显示与其他肝癌细胞株相比,Nur77蛋白在正常人肝细胞中表达稍低,在SMMC-7721和Hep3B高表达,而在HepG2细胞中的表达最低。因此,我们用Nur77siRNA处理SMMC-7721和Hep3B细胞并与未处理组(siGFP对照组)进行比较,Nur77过表达质粒转染HepG2细胞。Transwell小室结果显示与siGFP对照组相比,Nur77siRNA处理组在SMMC-7721和Hep3B两种细胞中的迁移和侵袭数目均减少(P均<0.05)。与pENTER空载质粒对照组相比,Nur77过表达组HepG2细胞的迁移和侵袭数目显著增多(P均<0.05)。结论Nur77可能通过促进肝癌细胞的迁移和侵袭从而介导肝癌的进展。

Objective To evaluate the effect of nuclear receptor Nur77 on the migration and invasion of human hepatocellular carcinoma cells. Methods The basic expression levels of Nur77 protein in normal human liver cell line L02 and liver cancer cell lines SMMC-7721, Bel-7402, Hep3B, SK-Hep1 and HepG2 were detected by Western blot. According to the expression of Nur77 protein in different cell lines, the expression of Nur77 protein was detected by Western blot after silencing Nur77 in SMMC-7721 and Hep3B cells and overexpressing Nur77 in HepG2 cells for 48 h. Meanwhile, the effect of silencing or overexpressing Nur77 upon the migration and invasion of the hepatocellular carcinoma cells was evaluated by using Transwell chamber. Results Western blot demonstrated that Nur77 protein was slightly expressed in normal human hepatocytes compared with those in other hepatocellular carcinoma cell lines. Nur77 protein was highly expressed in SMMC-7721 and Hep3B cells, whereas the least expressed in HepG2 cells. Therefore, we treated SMMC-7721 and Hep3B cells with Nur77 siRNA and compared them to the untreated group (siGFP control group), and the Nur77-overexpression plasmid was transfected into HepG2 cells. Compared with the siGFP control group, the number of migration and invasion of both SMMC-7721 and Hep3B cells was significantly decreased in the Nur77 siRNA group(all P < 0.05). Compared with the pENTER empty plasmid control group, the quantity of migration and invasion of HepG2 cells was significantly increased in the Nur77- overexpression group(both P < 0.05). Conclusion Nur77 mediates the progression of liver cancer probably by promoting the migration and invasion of hepatocellular carcinoma cells.