title: N-acetylcysteine blocks apoptosis induced by N-alpha-tosyl-L-phenylalanine chloromethyl ketone in transformed T-cells.
abstract: The serine protease inhibitor N-alpha-tosyl-L-phenylalanine chloromethyl ketone (TPCK) can interfere with cell-cycle progression and has also been shown either to protect cells from apoptosis or to induce apoptosis. We tested the effect of TPCK on two transformed T-cell lines. Both Jurkat T-cells and Theileria parva-transformed T-cells were shown to be highly sensitive to TPCK-induced growth arrest and apoptosis. Surprisingly, we found that the thiol antioxidant, N-acetylcysteine (NAC), as well as L- or D-cysteine blocked TPCK-induced growth arrest and apoptosis. TPCK inhibited constitutive NF-kappaB activation in T. parva-transformed T-cells, with phosphorylation of IkappaBalpha and IkappaBbeta being inhibited with different kinetics. TPCK-mediated inhibition of IkappaB phosphorylation, NF-kappaB DNA binding and transcriptional activity were also prevented by NAC or cysteine. Our observations indicate that apoptosis and NF-kappaB inhibition induced by TPCK result from modifications of sulphydryl groups on proteins involved in regulating cell survival and the NF-kappaB activation pathway(s).
authors.affiliation: Molecular Pathology, Institute of Animal Pathology, University of Berne, CH-3012 Berne, Switzerland.
authors.forename: V T
authors.initials: VT
authors.lastname: Heussler
authors.forename: P C
authors.initials: PC
authors.lastname: Fernandez
authors.forename: J
authors.initials: J
authors.lastname: Machado
authors.forename: C
authors.initials: C
authors.lastname: Botteron
authors.forename: D A
authors.initials: DA
authors.lastname: Dobbelaere
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology*; D000818:Animals; D017304:Annexin A5 / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects*; D002455:Cell Division / Q000187:drug effects; D002461:Cell Line, Transformed / Q000166:cytology / Q000187:drug effects / Q000469:parasitology; D003545:Cysteine / Q000494:pharmacology; D004268:DNA-Binding Proteins / Q000378:metabolism; D005434:Flow Cytometry; D016166:Free Radical Scavengers / Q000494:pharmacology*; D006801:Humans; D020672:I-kappa B Proteins; D019169:Jurkat Cells / Q000166:cytology* / Q000187:drug effects / Q000469:parasitology; D016328:NF-kappa B / Q000378:metabolism; D010766:Phosphorylation; D015842:Serine Proteinase Inhibitors / Q000494:pharmacology*; D016797:Theileria parva; D013801:Theileriasis / Q000276:immunology; D014108:Tosylphenylalanyl Chloromethyl Ketone / Q000494:pharmacology*; D015533:Transcriptional Activation / Q000187:drug effects
chemical_list: D017304:Annexin A5; D004268:DNA-Binding Proteins; D016166:Free Radical Scavengers; D020672:I-kappa B Proteins; D016328:NF-kappa B; D015842:Serine Proteinase Inhibitors; D014108:Tosylphenylalanyl Chloromethyl Ketone; D003545:Cysteine; D000111:Acetylcysteine