冬凌草甲素对NB4细胞的生长抑制作用及其作用机制

目的 探讨冬凌草甲素对白血病NB4细胞的生长抑制作用及其作用机制。方法 以不同浓度的冬凌草甲素作用于体外培养的NB4细胞,应用MTF法检测细胞生长抑制率,流式细胞仪检测细胞凋亡率,Hoechst 33258荧光染色法观察细胞凋亡,TRAP-PCR-ELISA法检测细胞凋亡前后的端粒酶活性。结果 8μmol／L以上的冬凌草甲素可显著降低NB4细胞端粒酶活性,抑制细胞的生长及诱导细胞发生凋亡,并呈现出明显的量-效与时-效关系。药物(16μmol／L)作用48～60h在Hoechst染色图片上可见核浓缩及核碎裂等典型的凋亡改变。结论 冬凌草甲素能抑制NB4细胞的生长并诱导细胞发生调亡,降低细胞端粒酶活性可能是其重要作用机制之一;这为冬凌草甲素进一步应用于临床治疗急性白血病提供了有力的试验依据。

Inhibitory Effect of Oridonin on the Proliferation of NB4 Cells and Its Mechanism

To investigate the anti-proliferation effect of oridonin on leukemic NB4 cells and its mechanism. NB4 cells in culture medium in vitro were given different concentrations of oridonin. The inhibitory rate of the cells were measured by MTT assay, cell apoptotic rate was detected by flow cytometry (FCM), morphology of cell apoptosis was observed by hoechst 33258 fluorescence staining, and the activity of telomerase was detected using TRAP-PCR-ELISA before and after apoptosis occurred. Oridonin (over 8 mol/L) could decrease the telomerase activity, inhibit the growth of NB4 cells and induce apoptosis significantly in a time- and dose-dependent manner. Marked morphological changes of cell apoptosis were observed by hoechst 33258 fluorescence staining especially after the cells treated by oridonin for 48—60 h. Oridonin could inhibit the proliferation and induce the apoptosis of NB4 cells in vitro. One of the mechanisms may be the decrease of the telomerase activity of NB4 cells.