蟾蜍灵对白血病K562细胞生长抑制机制

The mechanisms of inhibitory effect of bufalin on human leukemia K562 cells

目的探讨中药蟾酥有效成分蟾蜍灵对人白血病细胞系K562细胞增殖和凋亡的影响。方法倒置光显微镜、荧光显微镜、透射电镜观察细胞形态结构改变;MTT实验测定K562细胞对蟾蜍灵的敏感性;琼脂糖凝胶电泳分析细胞凋亡的DNA断裂情况;流式细胞术分析蟾蜍灵对细胞周期的影响。结果在光镜、荧光显微镜和电子显微镜下,蟾蜍灵作用K562细胞的形态和结构发生明显改变;蟾蜍灵对K562细胞的生长具有明显的抑制作用,与对照组细胞进行比较,差异具有显著性(P<0.05);MTT实验显示,蟾蜍灵对K562细胞的IC50值为0.013μmol/L,统计学分析证明,差异具有显著性(P<0.01);蟾蜍灵可明显诱导K562细胞调亡;经琼脂糖电泳,蟾蜍灵作用细胞可见到DNA梯形条带;蟾蜍灵可阻滞K562细胞于G2/M期。结论①蟾蜍灵对K562细胞的增殖抑制作用可能是因为它的凋亡诱导作用;②蟾蜍灵诱导K562细胞凋亡可能归功于G2/M期阻滞。

Objective To explore the effects of bufalinon on growth and apoptosis in myeloid leukemia cell line K562. Methods The changes of cellular morphology and structure were observed by light microscopy, fluoresin microscopy and electric microcopy. MTT assay were performed to evaluate the sensibility of K562 cells to bufalin. Apoptosis was detected by DNA gel electrophoresis. The cell cycle state were examined by flow cytometry（FCM）. Results Apparent morphological changes of cells treated by bufaiin were detected by light microscopy, fluoresin microscopy and electric microcopy. Compared with control, bufalin-treated K562 cells growth was remarkably reduced （ P d0.05）. By MTT assay, the ICso value of bufalin for K562 cells was 0. 013 gmol/L, the difference was significant by ststistic analysis（ P d0.01）. Agarose gel electrophoresis of genomic DNA from bufalin-treated K562 cells showed typical DNA ladder. Bufalin could efficiently induce apoptosis of leukemia cells in a close and timedependent manner. Bufalin arrested K562 ceils in the G2/M phase. Conclusion （i） Bufalin has a potent growth-inhibitory effect on human leukemia K562 cells. （2）Bufalin could efficiently induce apoptosis of leukemia K562 cells in the G2/M phase.