A human scFv antibody against TRAIL receptor 2 induces autophagic cell death in both TRAIL-sensitive and TRAIL-resistant cancer cells.
Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) induces apoptotic cell death in a variety of tumor cells without significant cytotoxicity on normal cells. However, many cancer cells with apoptotic defects are resistant to treatment with TRAIL alone, limiting its potential as an anticancer therapeutic. Here, we report on the tumoricidal activity of a human single-chain fragment variable, HW1, which specifically binds to TRAIL receptor 2 (TR2) without competing with TRAIL for the binding. HW1 treatment as a single agent induces autophagic cell death in a variety of both TRAIL-sensitive and TRAIL-resistant cancer cells, but exhibits much less cytotoxicity on normal cells. The HW1-induced autophagic cell death was inhibited by an autophagy inhibitor, 3-methyladenine, or by RNA interference knockdown of Beclin-1 and Atg7. We also show that the HW1-mediated autophagic cell death occurs predominantly via the c-Jun NH(2)-terminal kinase pathway in a caspase-independent manner. Analysis of the death-inducing signaling complex induced by HW1 binding to TR2 exhibits the recruitment of TNF receptor-associated death domain and TNF receptor-associated factor 2, but not Fas-associated death domain, caspase-8, or receptor-interacting protein, which is distinct from that induced by TRAIL. Our results reveal a novel TR2-mediated signaling pathway triggering autophagic cell death and provides a new strategy for the elimination of cancer cells, including TRAIL-resistant tumors, through nonapoptotic cell death.
Department of Molecular Science and Technology, Ajou University, Suwon 443-749, Korea.
Kyung-Jin
KJ
Park
Seung-Hyun
SH
Lee
Tae-In
TI
Kim
Hae-Won
HW
Lee
Chang-Han
CH
Lee
Eun-Hee
EH
Kim
Ji-Young
JY
Jang
Kyeong Sook
KS
Choi
Myung-Hee
MH
Kwon
Yong-Sung
YS
Kim
D017209:Apoptosis; D051017:Apoptosis Regulatory Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D001343:Autophagy; D000071193:Autophagy-Related Protein 7; D000071186:Beclin-1; D015153:Blotting, Western; D020169:Caspases / Q000378:metabolism; D002470:Cell Survival; D019008:Drug Resistance, Neoplasm; D053200:Fas-Associated Death Domain Protein / Q000378:metabolism; D006801:Humans; D007128:Immunoglobulin Fragments / Q000276:immunology*; D007135:Immunoglobulin Variable Region / Q000276:immunology*; D047468:Immunoprecipitation; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D008565:Membrane Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D008856:Microscopy, Fluorescence; D009369:Neoplasms / Q000378:metabolism* / Q000473:pathology; D034741:RNA, Small Interfering / Q000494:pharmacology; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand / Q000276:immunology* / Q000378:metabolism; D018124:Receptors, Tumor Necrosis Factor / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D053221:TNF-Related Apoptosis-Inducing Ligand / Q000378:metabolism*; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D044764:Ubiquitin-Activating Enzymes / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism
D051017:Apoptosis Regulatory Proteins; C491997:BECN1 protein, human; D000071186:Beclin-1; C505533:FADD protein, human; D053200:Fas-Associated Death Domain Protein; D007128:Immunoglobulin Fragments; D007135:Immunoglobulin Variable Region; D008565:Membrane Proteins; D034741:RNA, Small Interfering; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D018124:Receptors, Tumor Necrosis Factor; D011993:Recombinant Fusion Proteins; D053221:TNF-Related Apoptosis-Inducing Ligand; C505653:TNFSF10 protein, human; D014409:Tumor Necrosis Factor-alpha; D048031:JNK Mitogen-Activated Protein Kinases; D020169:Caspases; C509349:ATG7 protein, human; D000071193:Autophagy-Related Protein 7; D044764:Ubiquitin-Activating Enzymes