Apoptosis signal-regulating kinase 1 mediates denbinobin-induced apoptosis in human lung adenocarcinoma cells.
In the present study, we explore the role of apoptosis signal-regulating kinase 1 (ASK1) in denbinobin-induced apoptosis in human lung adenocarcinoma (A549) cells. Denbinobin-induced cell apoptosis was attenuated by an ASK1 dominant-negative mutant (ASK1DN), two antioxidants (N-acetyl-L-cysteine (NAC) and glutathione (GSH)), a c-Jun N-terminal kinase (JNK) inhibitor (SP600125), and an activator protein-1 (AP-1) inhibitor (curcumin). Treatment of A549 cells with denbinobin caused increases in ASK1 activity and reactive oxygen species (ROS) production, and these effects were inhibited by NAC and GSH. Stimulation of A549 cells with denbinobin caused JNK activation; this effect was markedly inhibited by NAC, GSH, and ASK1DN. Denbinobin induced c-Jun phosphorylation, the formation of an AP-1-specific DNA-protein complex, and Bim expression. Bim knockdown using a bim short interfering RNA strategy also reduced denbinobin-induced A549 cell apoptosis. The denbinobin-mediated increases in c-Jun phosphorylation and Bim expression were inhibited by NAC, GSH, SP600125, ASK1DN, JNK1DN, and JNK2DN. These results suggest that denbinobin might activate ASK1 through ROS production to cause JNK/AP-1 activation, which in turn induces Bim expression, and ultimately results in A549 cell apoptosis.
Kuo
Chen-Tzu
CT
Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan, ROC. bigkuo7@hotmaol.com
Chen
Bing-Chang
BC
Yu
Chung-Chi
CC
Weng
Chih-Ming
CM
Hsu
Ming-Jen
MJ
Chen
Chien-Chih
CC
Chen
Mei-Chieh
MC
Teng
Che-Ming
CM
Pan
Shiow-Lin
SL
Bien
Mauo-Ying
MY
Shih
Chung-Hung
CH
Lin
Chien-Huang
CH
D000230:Adenocarcinoma / Q000201:enzymology* / Q000378:metabolism; D000880:Anthraquinones / Q000633:toxicity*; D000970:Antineoplastic Agents / Q000633:toxicity*; D017209:Apoptosis; D016923:Cell Death; D045744:Cell Line, Tumor; D006801:Humans; D008175:Lung Neoplasms / Q000201:enzymology* / Q000378:metabolism; D048848:MAP Kinase Kinase Kinase 5 / Q000378:metabolism*; D010616:Phenanthrenes / Q000633:toxicity*; D017382:Reactive Oxygen Species / Q000378:metabolism
D000880:Anthraquinones; D000970:Antineoplastic Agents; D010616:Phenanthrenes; D017382:Reactive Oxygen Species; C436544:denbinobin; D048848:MAP Kinase Kinase Kinase 5