TY - JOUR AU - Zhong Li AU - Li Chao-ming AU - Hao Xiao-jiang AU - Lou Li-guang PY - 2016 TI - Induction of leukemia cell apoptosis by cheliensisin A involves downregulation of Bcl -2 expression JF - Acta Pharmacologica Sinica; Vol 26, No 5 (May 2005): Acta Pharmacologica Sinica Y2 - 2016 KW - N2 - Aim: To investigate the apoptosis-inducing effect of cheliensisin A (GC-51), a novel styryl-lactone isolated from Goniothalamus cheliensis , on human promyelocytic leukemia HL-60 cells and the mechanism of action involved. Methods: Apoptotic cell death was determined by morphological examination and DNA agarose gel electrophoresis. The activity of caspase-3 was assessed using Western blotting and the expression of Bcl -2 and Bax genes was analyzed using the reverse transcription-polymerase chain reaction (RT-PCR) method. Results: GC-51 significantly inhibited the proliferation of HL-60 cells with an IC 50 of 2.4plusminus0. 2 ìmol/L and effectively induced apoptosis in HL-60 cells. Exposure of HL-60 cells to 10 ìmol/L GC-51 for 8 h resulted in approximately 53% of the cells undergoing apoptosis. Caspase-3 was activated in GC-51-treated cells, which was manifested by the appearance of the 17 kDa active form of caspase-3 and the cleavage of poly(ADP-ribose) polymerase (PARP). Meanwhile, GC-51 markedly reduced the expression of the anti-apoptotic gene Bcl -2 and increased the expression of the pro-apoptotic gene Bax. The apoptosis-inducing effect of GC-51 was cAMP-dependent protein kinase (PKA) dependent because PKA, but not the protein kinase C, specific inhibitor H-89, blocked the induction of apoptosis by GC-51 in HL-60 cells. Conclusion: The results demonstrate that GC-51 effectively induces apoptosis in HL-60 cells and that this effect is PKA-dependent and involves the downregulation of Bcl -2 expression and the activation of caspase-3. UR - http://www.chinaphar.com/article/view/3721