title: NF-kappa B activation mediates doxorubicin-induced cell death in N-type neuroblastoma cells.
abstract: Neuroblastoma is the most common extracranial solid tumor of childhood. N-type neuroblastoma cells (represented by SH-SY5Y and IMR32 cell lines) are characterized by a neuronal phenotype. N-type cell lines are generally N-myc amplified, express the anti-apoptotic protein Bcl-2, and do not express caspase-8. The present study was designed to determine the mechanism by which N-type cells die in response to specific cytotoxic agents (such as cisplatin and doxorubicin) commonly used to treat this disease. We found that N-type cells were equally sensitive to cisplatin and doxorubicin. Yet death induced by cisplatin was inhibited by the nonselective caspase inhibitor z-Val-Ala-Asp-fluoromethylketone or the specific caspase-9 inhibitor N-acetyl-Leu-Glu-His-Asp-aldehyde, whereas in contrast, caspase inhibition did not prevent doxorubicin-induced death. Neither the reactive oxygen species nor the mitochondrial permeability transition appears to play an important role in this process. Doxorubicin induced NF-kappa B transcriptional activation in association with I-kappa B alpha degradation prior to loss of cell viability. Surprisingly, the antioxidant and NF-kappa B inhibitor pyrrolidine dithiocarbamate blocked doxorubicin-induced NF-kappa B transcriptional activation and provided profound protection against doxorubicin killing. Moreover, SH-SY5Y cells expressing a super-repressor form of I-kappa B were completely resistant to doxorubicin killing. Together these findings show that NF-kappa B activation mediates doxorubicin-induced cell death without evidence of caspase function and suggest that cisplatin and doxorubicin engage different death pathways to kill neuroblastoma cells.
authors.affiliation: Department of Pediatrics, University of Michigan Medical School, Ann Arbor, Michigan 48109-0938, USA.
authors.forename: X
authors.initials: X
authors.lastname: Bian
authors.forename: L M
authors.initials: LM
authors.lastname: McAllister-Lucas
authors.forename: F
authors.initials: F
authors.lastname: Shao
authors.forename: K R
authors.initials: KR
authors.lastname: Schumacher
authors.forename: Z
authors.initials: Z
authors.lastname: Feng
authors.forename: A G
authors.initials: AG
authors.lastname: Porter
authors.forename: V P
authors.initials: VP
authors.lastname: Castle
authors.forename: A W
authors.initials: AW
authors.lastname: Opipari
mesh_terms: D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000494:pharmacology* / Q000627:therapeutic use; D000975:Antioxidants / Q000494:pharmacology; D053181:Caspase 8; D053453:Caspase 9; D061945:Caspase Inhibitors; D020169:Caspases / Q000378:metabolism; D016923:Cell Death; D002648:Child; D002945:Cisplatin / Q000494:pharmacology; D004317:Doxorubicin / Q000494:pharmacology* / Q000627:therapeutic use; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005434:Flow Cytometry; D017930:Genes, Reporter; D006801:Humans; D016328:NF-kappa B / Q000378:metabolism*; D009447:Neuroblastoma / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology*; D010641:Phenotype; D011759:Pyrrolidines / Q000494:pharmacology; D013859:Thiocarbamates / Q000494:pharmacology; D014407:Tumor Cells, Cultured
chemical_list: D000590:Amino Acid Chloromethyl Ketones; D000970:Antineoplastic Agents; D000975:Antioxidants; D061945:Caspase Inhibitors; D004791:Enzyme Inhibitors; D016328:NF-kappa B; D011759:Pyrrolidines; D013859:Thiocarbamates; C096713:benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone; C020972:pyrrolidine dithiocarbamic acid; D004317:Doxorubicin; C505530:CASP8 protein, human; C506433:CASP9 protein, human; D053181:Caspase 8; D053453:Caspase 9; D020169:Caspases; D002945:Cisplatin