title: Bortezomib induces apoptosis of Epstein-Barr virus (EBV)-transformed B cells and prolongs survival of mice inoculated with EBV-transformed B cells.
abstract: Bortezomib, an inhibitor of the 26S proteasome, is currently approved for treatment of multiple myeloma and is being studied for therapy of non-Hodgkin's lymphoma. We found that Epstein-Barr virus (EBV)-positive B cells with type III latency were more susceptible to killing by bortezomib than those with type I latency. Bortezomib induced apoptosis of EBV lymphoblastoid cell lines (LCLs) by inducing cleavage of caspases 8 and 9; apoptosis was inhibited by pretreatment with a pan-caspase inhibitor. Bortezomib reduced the levels of the p50 and p65 components of the canonical NF-kappaB pathway and reduced the level of p52 in the noncanonical NF-kappaB pathway, which is induced by EBV LMP1. Bortezomib inhibited expression of cIAP-1, cIAP-2, and XIAP, which are regulated by NF-kappaB and function as inhibitors of apoptosis. Bortezomib did not inhibit expression of several other antiapoptotic proteins, including Bcl-2 and Bcl-XL. Finally, bortezomib significantly prolonged the survival of severe combined immunodeficiency mice inoculated with LCLs. These findings suggest that bortezomib may represent a novel strategy for the treatment of certain EBV-associated lymphomas.
authors.affiliation: Laboratory of Clinical Infectious Diseases, National Institutes of Health, 10 Center Drive, Bethesda, MD 20892, USA.
authors.forename: Ping
authors.initials: P
authors.lastname: Zou
authors.forename: Junichi
authors.initials: J
authors.lastname: Kawada
authors.forename: Lesley
authors.initials: L
authors.lastname: Pesnicak
authors.forename: Jeffrey I
authors.initials: JI
authors.lastname: Cohen
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology* / Q000627:therapeutic use; D017209:Apoptosis / Q000187:drug effects*; D000075747:Baculoviral IAP Repeat-Containing 3 Protein; D001897:Boronic Acids / Q000494:pharmacology* / Q000627:therapeutic use; D000069286:Bortezomib; D002051:Burkitt Lymphoma / Q000188:drug therapy* / Q000378:metabolism / Q000821:virology; D053181:Caspase 8 / Q000378:metabolism; D053453:Caspase 9 / Q000378:metabolism; D045744:Cell Line, Tumor; D002472:Cell Transformation, Viral / Q000187:drug effects*; D004854:Herpesvirus 4, Human / Q000378:metabolism*; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins / Q000378:metabolism; D051379:Mice; D016513:Mice, SCID; D009101:Multiple Myeloma / Q000188:drug therapy / Q000378:metabolism; D052002:NF-kappa B p50 Subunit / Q000378:metabolism; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D061988:Proteasome Inhibitors; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D011719:Pyrazines / Q000494:pharmacology* / Q000627:therapeutic use; D015398:Signal Transduction / Q000187:drug effects; D051996:Transcription Factor RelA / Q000378:metabolism; D044767:Ubiquitin-Protein Ligases; D014763:Viral Matrix Proteins / Q000378:metabolism; D017735:Virus Latency / Q000187:drug effects; D051636:X-Linked Inhibitor of Apoptosis Protein / Q000378:metabolism; D023041:Xenograft Model Antitumor Assays; D051020:bcl-X Protein / Q000378:metabolism
chemical_list: D000970:Antineoplastic Agents; C494811:BCL2L1 protein, human; D001897:Boronic Acids; C037662:EBV-associated membrane antigen, Epstein-Barr virus; D051034:Inhibitor of Apoptosis Proteins; D052002:NF-kappa B p50 Subunit; D061988:Proteasome Inhibitors; D019253:Proto-Oncogene Proteins c-bcl-2; D011719:Pyrazines; D051996:Transcription Factor RelA; D014763:Viral Matrix Proteins; D051636:X-Linked Inhibitor of Apoptosis Protein; C496866:XIAP protein, human; D051020:bcl-X Protein; D000069286:Bortezomib; C494832:BIRC3 protein, human; D000075747:Baculoviral IAP Repeat-Containing 3 Protein; D044767:Ubiquitin-Protein Ligases; C505530:CASP8 protein, human; D053181:Caspase 8; D053453:Caspase 9; D046988:Proteasome Endopeptidase Complex; C061553:ATP dependent 26S protease