title: C-jun N-terminal kinase activation is required for apoptotic cell death induced by TNF-related apoptosis-inducing ligand plus DNA-damaging agents in sarcoma cell lines.
abstract: BACKGROUND
  Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) in combination with a chemotherapeutic agent, cis-diammine dichloroplatinum (CDDP) or doxorubicin (DXR), has recently been demonstrated to result in enhanced apoptotic cell death in the sarcoma cell lines MG-63 and SaOS-2. DNA-damaging agents, such as CDDP induced sustained activation of c-Jun N-terminal kinase (JNK), probably leading to apoptosis. In the present study, whether JNK activation is involved in apoptotic cell death induced by combined treatment with CDDP/DXR and TRAIL was addressed.
  
  
  RESULTS
  MG-63 or SaOS-2 cells overexpressing the dominant-negative (dn) form of JNK (dnJNK1) were established by transfection with dnJNK1 cDNA. Following stimulation with the chemotherapeutic agent CDDP or TRAIL, both MG-63 and SaOS-2 cells demonstrated enhanced cell death compared with stimulation by either agent alone, as assayed for apoptosis using annexin V staining or mitochondrial membrane potential using DiOC6 staining. Interestingly, partial inhibition of the cell death induced by the combined treatment with CDDP/DXR and TRAIL was found in MG-63 or SaOS-2 cells overexpressing dnJNK1, suggesting that JNK activation is required for the combined treatment. Moreover, induction of caspase-8 activation by TRAIL or TRAIL plus CDDP/DXR was substantially prevented by dnJNK.
  
  
  CONCLUSIONS
  Efficient cell death induced by combined treatment with the chemotherapeutic agents CDDP/DXR and TRAIL is involved in JNK activation in the sarcoma cell lines MG-63 and SaOS-2. These results would be useful for treatment modalities of patients with sarcoma.
authors.affiliation: Department of Immunology, Tokyo Medical University, 6-1-1 Shinjuku, Shinjuku-ku, Tokyo 160-8402, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Mikami
authors.forename: Takaaki
authors.initials: T
authors.lastname: Koyama
authors.forename: Takashi
authors.initials: T
authors.lastname: Koyama
authors.forename: Atsuhiro
authors.initials: A
authors.lastname: Imakiire
authors.forename: Kengo
authors.initials: K
authors.lastname: Yamamoto
authors.forename: Masae
authors.initials: M
authors.lastname: Furuhata
authors.forename: Hiroko
authors.initials: H
authors.lastname: Toyota
authors.forename: Junichiro
authors.initials: J
authors.lastname: Mizuguchi
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology; D051017:Apoptosis Regulatory Proteins / Q000008:administration & dosage; D053181:Caspase 8; D020169:Caspases / Q000378:metabolism; D045744:Cell Line, Tumor; D002945:Cisplatin / Q000008:administration & dosage; D004249:DNA Damage; D004317:Doxorubicin / Q000008:administration & dosage; D004789:Enzyme Activation; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000008:administration & dosage; D008564:Membrane Potentials / Q000187:drug effects; D051336:Mitochondrial Membranes / Q000187:drug effects / Q000502:physiology; D012509:Sarcoma / Q000188:drug therapy* / Q000201:enzymology* / Q000473:pathology; D053221:TNF-Related Apoptosis-Inducing Ligand; D014409:Tumor Necrosis Factor-alpha / Q000008:administration & dosage
chemical_list: D051017:Apoptosis Regulatory Proteins; D008562:Membrane Glycoproteins; D053221:TNF-Related Apoptosis-Inducing Ligand; C505653:TNFSF10 protein, human; D014409:Tumor Necrosis Factor-alpha; D004317:Doxorubicin; D048031:JNK Mitogen-Activated Protein Kinases; C505530:CASP8 protein, human; D053181:Caspase 8; D020169:Caspases; D002945:Cisplatin