Doxorubicin-induced death in neuroblastoma does not involve death receptors in S-type cells and is caspase-independent in N-type cells.
Death induced by doxorubicin (dox) in neuroblastoma (NB) cells was originally thought to occur via the Fas pathway, however since studies suggest that caspase-8 expression is silenced in most high stage NB tumors, it is more probable that dox-induced death occurs via a different mechanism. Caspase-8 silenced N-type invasive NB cell lines LAN-1 and IMR-32 were investigated for their sensitivity to dox, and compared to S-type noninvasive SH-EP NB cells expressing caspase-8. All cell lines had similar sensitivities to dox, independently of caspase-8 expression. Dox induced caspase-3, -7, -8 and -9 and Bid cleavage in S-type cells and death was blocked by caspase inhibitors but not by oxygen radical scavenger BHA. In contrast, dox-induced death in N-type cells was caspase-independent and was inhibited by BHA. Dox induced a drop in mitochondrial membrane permeability in all cell lines. Dox-induced death in S-type cells gave rise to apoptotic nuclei, whereas in N-type cells nuclei were non-apoptotic in morphology. Transfection of SH-EP cells with a dominant negative FADD mutant inhibited TRAIL-induced death, but had no effect on dox-induced apoptosis. These results suggest that S-type cells undergo apoptosis after dox treatment independently of death receptors, whereas N-type cells are killed by a caspase-independent mechanism.
Hopkins-Donaldson
Sally
S
Department of Pediatric Onco-Hematology, Centre Hospitalier Universitaire Vaudois, CH1011 Lausanne, Switzerland.
Yan
Pu
P
Bourloud
Katia Balmas
KB
Muhlethaler
Annick
A
Bodmer
Jean-Luc
JL
Gross
Nicole
N
D048868:Adaptor Proteins, Signal Transducing; D000970:Antineoplastic Agents / Q000494:pharmacology*; D000975:Antioxidants / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology; D051017:Apoptosis Regulatory Proteins; D002083:Butylated Hydroxyanisole / Q000494:pharmacology; D002352:Carrier Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D061945:Caspase Inhibitors; D020169:Caspases / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D004317:Doxorubicin / Q000494:pharmacology*; D019008:Drug Resistance, Neoplasm / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D053200:Fas-Associated Death Domain Protein; D005799:Genes, Dominant; D006801:Humans; D008562:Membrane Glycoproteins / Q000494:pharmacology; D009361:Neoplasm Invasiveness / Q000503:physiopathology; D009447:Neuroblastoma / Q000188:drug therapy* / Q000378:metabolism* / Q000473:pathology; D017382:Reactive Oxygen Species; D053221:TNF-Related Apoptosis-Inducing Ligand; D014162:Transfection; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism
D048868:Adaptor Proteins, Signal Transducing; D000970:Antineoplastic Agents; D000975:Antioxidants; D051017:Apoptosis Regulatory Proteins; D002352:Carrier Proteins; D061945:Caspase Inhibitors; D004791:Enzyme Inhibitors; C505533:FADD protein, human; D053200:Fas-Associated Death Domain Protein; D008562:Membrane Glycoproteins; D017382:Reactive Oxygen Species; D053221:TNF-Related Apoptosis-Inducing Ligand; C505653:TNFSF10 protein, human; D014409:Tumor Necrosis Factor-alpha; D016159:Tumor Suppressor Protein p53; D002083:Butylated Hydroxyanisole; D004317:Doxorubicin; D020169:Caspases