NF-κB信号通路阻断对肝癌细胞SMMC7721增殖的影响

Suppress of Cell Proliferation and Survival by Nuclear Factor-kappa B Signaling Pathway Inhibition in Human Hepatocellular Carcinoma SMMC-7721 Cells

目的研究NF-κB信号通路阻断对肝癌细胞SMMC7721生长增殖的影响。方法常规培养SMMC7721细胞,采用SN50(36μmol/L)阻断NF-κB信号通路,Western blot检测核内p65蛋白水平,MTT比色法检测细胞生长增殖,计算肿瘤细胞生长抑制率,PI染色、流式细胞仪分析细胞周期与凋亡,观察NF-κB信号通路阻断对肝癌细胞SMMC7721细胞周期及凋亡的影响。结果肝细胞癌SMMC7721细胞核内存在较高水平的p65蛋白。经SN50阻断后,MTT测定显示细胞的增殖受到明显抑制,并随时间的延长而愈渐明显,24、48、72h后细胞增殖抑制率分别为22.77%、33.33%和38.89%,与阻断前相比,差异有统计学意义(P<0.05)。流式细胞仪检测发现实验组G1期细胞比例高于对照组差异有统计学意义(69.5% vs 56.5%,P<0.05),S期细胞比例明显降低,与阻断前相比差异有统计学意义(11.1% vs 28.6%,P<0.05),而细胞凋亡率在实验组为38.3%,对照组仅为23.2%,差异有统计学意义(P<0.05)。结论NF-κB信号通路阻断诱导细胞周期于G1期停滞和细胞凋亡,从而抑制了SMMC7721细胞生长与增殖,提示NF-κB信号通路组成性激活参与了肝细胞癌的生长增殖与发展,以NF-κB信号通路作为治疗的靶点可能给肝细胞癌带来新的治疗选择。

Objective To evaluate the effect of NF-κB inhibition on the proliferation of SMMC7721 cells and to find out whether it would be a potential therapeutic target for hepatocellular carcinoma. Methods Human hepatocellular carcinoma cells SMMC7721 were cultured in RPMI1640 medium and NF-κB activity was suppressed by SN50 （36/xmol/L）. Western blot were used to analysis the p65 subunite of NF-κB in the nucleus of SMMC7721 cells. Cell viability was assessed by MTT assay. Cell cycle progression and cell apoptosis were analyzed by flow cytometry. Results The p65 subunits of NF-κB were constitutively expressed in the nucleus of SMMC7721 cells but decreased significantly after SN50 （36 μmol/L） treatment. MTT assay showed that the proliferation of SMMC7721 cells was significantly suppressed by SN50 in a time-dependent way （P〈0.05）. The inhibition rate was 22.77%, 33.33% and 38.89% for 24, 48 and 72 hours respectively. The cell cycle distribution and apoptosis analyzed by flow cytometry showed that the percentage of SMMC7721 cells in G1 phase was increased（69.5% vs 56.5%, P〈0.05）and decreased in S phase （11.1% vs 28.6% ,P〈0.05）with SN50 treatment. At the same time,SN50 induced 38.3% apoptosis compared with 23.2% in the controls （P〈0.05）. Conclusion NF-κB functions in the cell proliferation and survival in human hepatocellular carcinoma SMMC-7721 cells. Inhibition of NF-κB activity would induce cell apoptosis and cell cycle arrest in the G1 phase. It confers that targeting NF-κB signaling pathway would be a new choice for the therapy of HCC.