低相对分子质量肝素对人肝癌细胞生长的影响及机制

目的探讨低相对分子质量肝素（LMWH）对体外培养人肝癌细胞SMMC-7721增殖、细胞周期分布及周期调控相关基因Skp2和c-Mye表达的影响。方法体外培养SMMC-7721细胞，经不同浓度LMWH作用不同时间后，MTT比色法检测细胞存活和生长情况。将对照组和LMWH处理组（400、800IU／mL）细胞培养36h后，流式细胞术检测细胞周期分布情况；RT-PCR检测细胞Skp2、c-MyemRNA表达的变化；Western blotting检测skp2、c-Myc蛋白表达的变化。结果与对照组相比，经LMWH作用后SMMC-7721细胞的生长受到抑制，且在一定范围内呈药物浓度和时间依赖关系；细胞周期分布发生变化，随LMWH剂量增加，S期细胞比例显著下降（P〈0．05），G0／G1期细胞比例显著上升（P〈0．05）；同时，Skp2、c-Mye的mRNA和蛋白的表达量均呈剂量依赖性降低（P〈0．05）。结论LMWH可抑制SMMC-7721细胞的生长，其机制可能与降低Skp2、c-Myc的表达，阻滞细胞于G0／G1期，从而降低细胞增殖指数有关。

Effects of low molecular weight heparin on proliferation of human hepatocacinoma cells and its mechanism

Objective To investigate the effects of low molecular weight heparin （LMWH） on proliferation and cell cycle distribution of human hepatocacinoma cell line SMMC-7721 cultured in vitro, and expressions of Skp2 and c-Myc relevant to cycle regulation. Methods SMMC-7721 ceils were cultured in vitro then treated by LMWH of different concentrations for different periods of time. Then the cell survival and growth were determined by MTT assay. After cells of negative control group and LMWH treated groups （400 IU/mL and 800 IU/mL） were cultured for 36 h, the cell cycle distributions were analyzed by flow cytometry; alterations of Skp2 and c-Myc mRNA were examined by RT-PCR; and expression alterations of Skp2 and c~Myc proteins were investigated by Western blotting. Results Compared to negative control group, the cell proliferation of LMWH treated groups was inhibited and presented dose-dependent and time-dependent within a certain range. The cell cycle distributions altered and with the increasing of LMWH dose, the percent of cells in S phase decreased （P 〈0.05） and G0/G1 phase increased （P 〈 0.05）. In addition, the mRNA and protein expressions of Skp2 and e-Myc were dose-dependently reduced （P 〈 0.05）. Conclusion LMWH can inhibit the proliferation of SMMC-7721 ceils. The mechanism may be relevant to reducing the expressions of Skp2 and c-Myc and arresting cell cycle at G0/G1 phase and consequently decreasing the cell proliferation index.