莱菔硫烷诱导HepG-2细胞G2/M期阻滞及其对Cdk1和CyclinB1蛋白表达的影响

目的：研究莱菔硫烷（SFN）在体外对人肝癌HepG-2细胞G2/M期的阻滞作用,并探讨其分子作用机制。方法：10、20、40μmol·L-1的SFN处理体外培养的HepG-2细胞株48h后,采用流式细胞仪检测SFN对HepG2细胞周期的影响;WesternBlot法检测SFN对HepG2细胞内Cdk1、p-Cdk1（Thr14）和CyclinB1蛋白表达的影响。结果：SFN作用于HepG-2细胞48h后,随着SFN浓度的增大,G2/M期细胞比例逐渐升高,当SFN浓度达到40μmol·L-1时,G2/M期细胞比例达到31.95%,且出现凋亡峰;随SFN浓度的增大,细胞内Cdk1和CyclinB1蛋白的表达量显著降低（P〈0.01或P〈0.05）,同时p-Cdk1（Thr14）的表达显著升高（P〈0.01或P〈0.05）。结论：SFN可诱导人肝癌HepG-2细胞发生G2/M期阻滞;SFN可通过下调HepG-2细胞内Cdk1和CyclinB1蛋白的表达、上调p-Cdk1（Thr14）的蛋白表达水平,进而抑制Cdk1-CyclinB1复合物的形成和活化使人肝癌HepG-2细胞阻滞在G2/M期。

Effects of Sulforaphane on G_2 /M Phase Arrest in HepG-2 Cells and the Expression of Cdk1 and CyclinB1

Objective：To investigate the effect of Sulforaphane （SFN） on G2 /M phase arrest of human liver cancer HepG-2 cells in vitro and its molecular mechanism. Methods HepG-2 cells were treated with 10,20 and 40 μmol/L of SFN for 48h. Flow cytometry （FCM） was used to analyze the phase distribution of cell cycle. The expression of Cdk1,pCdk1（Thr14） and CyclinB1 was determined by Western Blotting. Results：After treated with different concentration of SFN for 48 h,HepG-2 cells presented with increasing percentages of cells in the G2 /M phase as the concentration of SFN increased. At the dosage of 40 μmol/L,the proportion of HepG-2 cells in G2 /M phase was 31. 95% and the apoptotic sub-G1 peak appeared. With the increase of SFN dose,the expresstion of Cdk1 and CyclinB1 protein was remarkably decreased（P 0. 05 or P 0. 01） and the expresstion of p-Cdk1（Thr14） protein was increased markedly（P 0. 05 or P 0. 01）. Conclusion： SFN can induce G2 /M phase arrest in HepG-2 cells in vitro. SFN can down-regulate the expression of Cdk1 and CyclinB1 and up-regulating the expression of p-Cdk1 （Thr14） protein,which may be one of the main mechanism of SFN inducing G2 /M phase arrest in human liver cancer HepG-2 cells.