[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 apoptosis via mitochondrial pathway in K562 cells. Key words: Polyamine;  K562 cells ;  Apoptosis;  Mitochondrial membrane potential