淫羊藿苷对NB4白血病细胞株增殖和凋亡的影响及其作用机制

Influence of icaritin in proliferation and apoptosis of NB4 leukemia cells and its mechanism

目的:研究淫羊藿苷(ICA)对急性早幼粒细胞白血病NB4细胞株增殖和凋亡的影响,探讨其作用机制。方法:选取处于对数生长期的NB4细胞,随机分为空白对照组和不同浓度(4、8、16、32和64μmol·L-1)ICA组,采用MTT法检测作用不同时间(24、48和72h)后各组NB4细胞增殖活性,流式细胞术检测各组细胞24h时细胞周期进程及48h时凋亡情况,采用Western blotting法检测各组NB4细胞48h时凋亡相关蛋白的表达水平。结果:细胞培养不同时间(24、48和72h)后,各ICA组细胞增殖抑制率高于空白对照组(P<0.05),随ICA浓度增加和作用时间延长,细胞增殖抑制率升高(P<0.05)。各浓度ICA(4、8、16、32和64μmol·L-1)组NB4细胞48h后细胞凋亡率分别为(6.52±4.12)%、(10.07±2.36)%、(15.41±3.64)%、(25.18±1.24)%和(29.41±1.43)%,与空白对照组[(2.39±1.87)%]比较差异均有统计学意义(P<0.05)。各浓度ICA(8、16、32和64μmol·L-1)组NB4细胞24h后S期NB4细胞百分率降低,G1期细胞百分率升高,与空白对照组比较差异均有统计学意义(P<0.05)。Western blotting检测,与空白对照组比较,各浓度ICA组NB4细胞Bcl-2蛋白表达水平明显降低(P<0.05),而Bax蛋白表达水平明显升高(P<0.05)。结论:ICA通过抑制Bcl-2蛋白表达水平和上调Bax蛋白表达水平诱导急性早幼粒细胞白血病NB4细胞株凋亡。

Objective To investigate the influence of icariin （ICA） on the proliferation and apoptosis of acute promyelocytic leukemia NB4 cells, and to explore its mechanism. Methods The NB4 cells at logarithm growth phase were selected and randomly divided into blank control group, different doses （4, 8, 16, 32, 64 μmol · L 1 ） of ICA groups. Afer the NB4 cells were treated with ICA for different time （24, 48, 72 h）, MTT assay was used to detect the inhibitory rates of NB4 cells, flow cytometry was used to analyze the apoptosis and the cell cycle of the NB4 cells, and the expression levels of apoptosis-associated proteins were detected by Western blotting method. Results Afer the cells were cultivated for different time （24, 48, 72 h）, the inhibitory rates of the cells in different doses of ICA groups were higher than those in control group （P〈 0.05） and they were increased in a dose-and time-dependent manner （P〈0.05）. The apoptotic rates of NB4 cells in different doses of ICA group 48 h after treatment were （6.52±4.12）%, （10.07-＋2.36）%, （15.41±3.64）%, （25.18±1.24）% and （29.41±1.43） %, and they were higher than that in control group （2.39%±1.87%） （P〈0.05）. The flow cytometry results showed that after the cells were cultivated for 24 h in different doses of ICA groups, the number of NB4 cells at S phase was lower than those in control group （P 〈0.05）,and the number of NB4 cells at G1 phase was increased （P 〈0.05）.The expression levels of Bcl-2 in ICA groups were significantly lower than that in control group （P 〈 0.05 ）, while the expression levels of Bax were higher than that in control group （P 〈 0.05 ）. Conclusion ICA can induce the apoptosis of NB4 cells via inhibiting the expression level of Bcl-2 and up-regulating the expression level of Bax.