精氨酸甲基转移酶抑制剂1通过下调蛋白质精氨酸甲基转移酶5表达抑制肝细胞癌生长

Inhibition of Arginine Methyltransferase Inhibitor 1 to the Growth of Hepatocellular Carcinoma by Downregulating the Expression of Protein Arginine Methyltransferase 5

目的:探讨精氨酸甲基转移酶抑制剂1(AMI-1)通过抑制蛋白质精氨酸甲基转移酶5(PRMT5)对肝癌细胞系SMMC-7721和BEL-7402的抗肿瘤作用。方法:以含有AMI-1(终浓度0.6,1.2,2.4 mmol·L^(-1))的培养基培养SMMC-7721和BEL-7402细胞后,CCK-8试剂盒检测细胞增殖率;菌落形成实验检测细胞菌落形成情况;裸鼠模型肿瘤形成实验评估体内肿瘤生长;流式细胞术分析细胞周期分布。结果:与人正常肝细胞系LO2相比,人肝癌细胞系SMMC-7721和BEL-7402中RPMT5、真核起始因子4E(eIF4E)、细胞周期蛋白D1(cyclin D1)蛋白表达均显著增加(P<0.05)。与对照组相比,AMI-1处理组细胞增殖率、集落形成数量、肿瘤体积、肿瘤重量均显著降低,G0/G1期DNA含量均显著增加,RPMT5、eIF4E、cyclin D1蛋白表达水平均显著降低(P<0.05)。随着AMI-1浓度的增加,各指标差异均有统计学意义(P<0.05)。结论:AMI-1可能通过抑制PRMT5和eIF4E的表达,引起细胞周期G0/G1期阻滞,从而抑制肝癌细胞系SMMC-7721和BEL-7402体内和体外生长,发挥抗肿瘤形成作用。

Objective: To investigate the antitumor effect of arginine methyltransferase inhibitor 1 (AMI-1) on hepatocellular carcinoma cell lines SMMC-7721 and BEL-7402 by inhibiting protein arginine methyltransferase 5 (PRMT5). Methods: After SMMC-7721 and BEL-7402 cells were cultured in the medium containing AMI-1 with the final concentration of 0.6,1.2 and 2.4 mmol·L-1,CCK-8 kit was used to detect the cell proliferation rate,colony formation assay was used to detect the cell colony formation,nude mice model tumor formation assay was used to evaluate tumor growth in vivo,and the cell cycle distribution was analyzed by flow cytometry.Results: Compared with those of human normal hepatocyte line LO2,the expressions of RPMT5,eIF4E and cyclin D1 in SMMC-7721 and BEL-7402 cells were significantly increased (P<0.05). Compared with those in the control group,the cell proliferation rate,colony forming quantity,tumor volume and tumor weight significantly decreased,the content of DNA in G0/G1 phase increased significantly,and the expression levels of RPMT5,eIF4E and cyclin D1 were decreased significantly in the AMI-1 treatment group (P< 0.05).With the concentration increase of AMI-1,the difference of each index was statistically significant (P<0.05).Conclusion: AMI-1 may inhibit the growth of SMMC-7721 and BEL-7402 cell lines by inhibiting the expressions of PRMT5 and eIF4E,which leads to cell cycle arrest in G0/G1 phase resulting in anti-tumor effect.