N(alpha)-tosyl-L-phenylalanine chloromethyl ketone induces caspase-dependent apoptosis in transformed human B cell lines with transcriptional down-regulation of anti-apoptotic HS1-associated protein X-1

• Published in: The Journal of biological chemistry Vol. 284; no. 41; p. 27827
• Main Authors: Jitkaew, Siriporn, Trebinska, Alicja, Grzybowska, Ewa, Carlsson, Göran, Nordström, Anders, Lehtiö, Janne, Fröjmark, Anne-Sophie, Dahl, Niklas, Fadeel, Bengt
• Format: Journal Article
• Language: English
• Published: United States 09.10.2009
• Subjects: Acetylcysteine - metabolism; Adaptor Proteins, Signal Transducing; Antioxidants - metabolism; Apoptosis - drug effects; Apoptosis - physiology; B-Lymphocytes - cytology; B-Lymphocytes - drug effects; B-Lymphocytes - metabolism; Baculoviral IAP Repeat-Containing 3 Protein; Caspases - metabolism; Cell Line, Transformed; Cell Transformation, Neoplastic; Coumarins - metabolism; Cysteine - metabolism; Dose-Response Relationship, Drug; Down-Regulation - drug effects; Fluorescent Dyes - metabolism; Herpesvirus 4, Human - genetics; Herpesvirus 4, Human - metabolism; Humans; Inhibitor of Apoptosis Proteins - genetics; Inhibitor of Apoptosis Proteins - metabolism; Jurkat Cells; MEDICIN; MEDICINE; Mitochondria - drug effects; Mitochondria - metabolism; NF-kappa B - antagonists & inhibitors; NF-kappa B - metabolism; Oligopeptides - metabolism; Poly(ADP-ribose) Polymerases - genetics; Poly(ADP-ribose) Polymerases - metabolism; Protein Synthesis Inhibitors - pharmacology; Proteins - genetics; Proteins - metabolism; Proto-Oncogene Proteins c-bcl-2 - metabolism; Reactive Oxygen Species - metabolism; Tosylphenylalanyl Chloromethyl Ketone - pharmacology; Transcription, Genetic - drug effects; Ubiquitin-Protein Ligases; X-Linked Inhibitor of Apoptosis Protein - genetics; X-Linked Inhibitor of Apoptosis Protein - metabolism
• ISSN: 1083-351X; 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M109.027912

N(alpha)-tosyl-L-phenylalanine chloromethylketone (TPCK) has been widely used to investigate signal transduction pathways that are involved in gene expression and cell survival/cell death. However, contradictory effects of TPCK on apoptosis have been reported, and the underlying signaling events leading to TPCK-induced promotion or prevention of apoptosis are not fully understood. Here, we show that TPCK induces caspase-dependent apoptosis in Epstein-Barr virus (EBV)-transformed human B cell lines with release of pro-apoptotic proteins from mitochondria. TPCK treatment also results in down-regulation of the anti-apoptotic proteins, cIAP1, cIAP2, and HAX-1, and caspase-dependent cleavage of the anti-apoptotic proteins, Bcl-2 and XIAP. Quantitative PCR analysis confirmed that the TPCK-induced down-regulation of HAX-1 occurred at the transcriptional level, and experiments using the specific pharmacological inhibitor, Bay 11-7082, suggested that HAX-1 expression is subject to regulation by the transcription factor, NF-kappaB. B cell lines derived from patients with homozygous HAX1 mutations were more sensitive to TPCK-induced apoptosis when compared with normal donor cell lines. Furthermore, N-acetylcysteine effectively blocked TPCK-induced apoptosis in EBV-transformed B cell lines and prevented the down-regulation or cleavage of anti-apoptotic proteins. Taken together, our studies demonstrate that TPCK induces apoptosis in human B cell lines and exerts multiple effects on pro- and anti-apoptotic factors.