新型多胺缀合物NNAMB诱导K562细胞凋亡及其机制

目的 探讨新型多胺缀合物NNAMB诱导K562细胞凋亡及其分子机制.方法 采用二苯基溴化四氮唑蓝(MTT)法、台盼监拒染法检测细胞活力;Hoechst33258染色观察细胞形态变化;流式细胞仪检测细胞周期变化、凋亡率、线粒体膜电位的变化;Western blot检测caspase-3、caspase-8、caspase-9和cytochrome c的表达.结果 NNAMB抑制K562细胞的生长,并呈现剂量及时间依赖性.随着NNAMB浓度的增加和作用时间的延跃,Sub-G1期细胞明显增加,线粒体膜电位下降.经NNAMB处理后的K562细胞中,可见到明显的凋亡细胞.蛋白印迹检测表明,NNAMB可诱导caspase-3、easpase-9的活化及线粒体cytochrome c释放到胞浆中,但caspase-8的表达无明显变化.结论 NNAMB能显著抑制K562细胞增殖,并可通过内源性线粒体途径诱导细胞凋亡.

Apoptosis induced by NNAMB, a novel polyamine conjugate, in human erythroleukemia K562 cells and its mechanism

Objective To investigate the apoptosis-inducing effects of NNAMB, a novel polyamine conjugate, in erythroleukemia K562 cells and its molecular mechanism. Methods Cell viability was assessed by MTT assay and trypan blue dye exclusion method. The cell morphology was observed by fluorescence microscopy. The cell cycle distribution, apoptosis and mitochondrial membrane potential were measured by flow cytometry. The expression of caspase-3, -8, -9, cytochrome c in the K562 cells was detected by Western blot. Results NNAMB inhibited the proliferation of K562 cells. The cells treated with NNAMB showed a typical apoptotic morphology, Sub-G1 peak and loss of mitochondrial membrane potential. Western blot assay showed that NNAMB increased the expression of caspase-3, -9, cytochrome c but not caspase-8 in a dose-and time-dependent manner. Conclusion NNAMB induces apoptasis via mitochondrial pathway in K562 cells.