title: Caspase-9 regulates cisplatin-induced apoptosis in human head and neck squamous cell carcinoma cells.
abstract: The aim of this study was to understand the molecular requirements for cisplatin-induced apoptosis in human head and neck squamous cell carcinoma (HNSCC) cell death. Cisplatin induced apoptosis in HNSCC cell lines, HSC-2, HSC-3 and HSC-4 in a dose-dependent manner. However, cisplatin did not induce the expression of Fas-ligand mRNA or upregulation of Fas protein. By caspase activation assays, cisplatin induced Caspase-3 (Casp-3), -8 and -9 activation. In all three lines tested, the use of a specific inhibitor of Casp-9 almost completely blocked cisplatin-induced apoptosis, while the use of Casp-3 and -8 inhibitors resulted in a partial blockade of cisplatin-induced apoptosis. Our results strongly suggest that Casp-9-dependent apoptosis plays an important role in cisplatin-induced HNSCC apoptosis.
authors.affiliation: Department of Otorhinolaryngology, St. Marianna University School of Medicine, Kawasaki, Kanagawa, Japan.
authors.forename: D
authors.initials: D
authors.lastname: Kuwahara
authors.forename: K
authors.initials: K
authors.lastname: Tsutsumi
authors.forename: T
authors.initials: T
authors.lastname: Kobayashi
authors.forename: T
authors.initials: T
authors.lastname: Hasunuma
authors.forename: K
authors.initials: K
authors.lastname: Nishioka
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D002294:Carcinoma, Squamous Cell / Q000201:enzymology / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D053148:Caspase 3; D053181:Caspase 8; D053453:Caspase 9; D061945:Caspase Inhibitors; D020169:Caspases / Q000378:metabolism*; D002945:Cisplatin / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation / Q000187:drug effects; D053222:Fas Ligand Protein; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006258:Head and Neck Neoplasms / Q000201:enzymology / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D008562:Membrane Glycoproteins / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013997:Time Factors; D014407:Tumor Cells, Cultured; D019014:fas Receptor / Q000378:metabolism
chemical_list: D061945:Caspase Inhibitors; C505661:FASLG protein, human; D053222:Fas Ligand Protein; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D019014:fas Receptor; C505407:CASP3 protein, human; C505530:CASP8 protein, human; C506433:CASP9 protein, human; D053148:Caspase 3; D053181:Caspase 8; D053453:Caspase 9; D020169:Caspases; D002945:Cisplatin