An agonistic monoclonal antibody against DR5 induces ROS production, sustained JNK activation and Endo G release in Jurkat leukemia cells.
We have previously reported that AD5-10, a novel agonistic monoclonal antibody against DR5, possessed a strong cytotoxic activity in various tumor cells, via induction of caspase-dependent and -independent signaling pathways. The present study further demonstrates that reactive oxygen species (ROS) were generated in abundance in Jurkat leukemia cells upon AD5-10 stimulation and that ROS accumulation subsequently evoked sustained activation of c-Jun N-terminal kinase (JNK), loss of mitochondrial membrane potential, and release of endonuclease G (Endo G) from mitochondria into the cytosol. The reducing agent, N-acetylcysteine (NAC), effectively inhibited the sustained activation of JNK, release of Endo G, and cell death in Jurkat cells treated by AD5-10. Moreover, a dominant-negative form of JNK (but not of p38) enhanced NF-kappaB activation, suppressed caspase-8 recruitment in death-inducing signaling complexes (DISCs), and reduced adverse effects on mitochondria, thereby inhibiting AD5-10-induced cell death in Jurkat leukemia cells. These data provide novel information on the DR5-mediated cell death-signaling pathway and may shed new light on effective strategies for leukemia and solid tumor therapies.
Chen
Caifeng
C
National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College, 5 Dong Dan San Tiao, Beijing 100005, China.
Liu
Yanxin
Y
Zheng
Dexian
D
D000111:Acetylcysteine / Q000494:pharmacology; D000911:Antibodies, Monoclonal / Q000494:pharmacology*; D017209:Apoptosis; D053181:Caspase 8 / Q000378:metabolism; D045744:Cell Line, Tumor; D004706:Endodeoxyribonucleases / Q000378:metabolism*; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism*; D019169:Jurkat Cells; D007938:Leukemia / Q000201:enzymology / Q000378:metabolism*; D053078:Membrane Potential, Mitochondrial; D008928:Mitochondria / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism*; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand / Q000819:agonists / Q000378:metabolism*; D015398:Signal Transduction
D000911:Antibodies, Monoclonal; D016328:NF-kappa B; D017382:Reactive Oxygen Species; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D048031:JNK Mitogen-Activated Protein Kinases; D004706:Endodeoxyribonucleases; C052391:endonuclease G; D053181:Caspase 8; D000111:Acetylcysteine