title: The class-I HDAC inhibitor MGCD0103 induces apoptosis in Hodgkin lymphoma cell lines and synergizes with proteasome inhibitors by an HDAC6-independent mechanism.
abstract: Inhibition of histone deacetylase 6 (HDAC6)-dependent aggresome function by pan HDAC inhibitors was recently reported to be a key mechanism underlying the synergistic activity between proteasome inhibitors and HDAC inhibitors in a variety of tumour types. Because these combinations induce significant thrombocytopenia in vivo, we examined whether less toxic, isotype-selective HDAC inhibitors may still synergize with proteasome inhibitors, and if so, by what mechanisms. Here, we showed that the class I HDAC inhibitor, MGCD0103, has a potent antiproliferative activity in Hodgkin lymphoma (HL) cell lines. Furthermore, MGCD0103 induced tumour necrosis factor α (TNF-α) expression and secretion, which was associated with nuclear factor (NF)-κB activation. Selective inhibition of TNF-α expression by short interfering mRNA, or inhibition of MGCD0103-induced NF-kB activation by proteasome inhibitors enhanced MGCD0103-induced cell death. Thus, our results demonstrate that MGCD0103 may synergize with proteasome inhibitors by HDAC6-independent mechanisms, providing mechanistic rationale for exploring this potentially less toxic combination for the treatment of lymphoma.
authors.affiliation: M. D. Anderson Cancer Center, Department of Lymphoma/Myeloma, Houston, University of Texas, TX, USA.
authors.forename: Daniela
authors.initials: D
authors.lastname: Buglio
authors.forename: Vidya
authors.initials: V
authors.lastname: Mamidipudi
authors.forename: Noor M
authors.initials: NM
authors.lastname: Khaskhely
authors.forename: Helen
authors.initials: H
authors.lastname: Brady
authors.forename: Carla
authors.initials: C
authors.lastname: Heise
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Besterman
authors.forename: Robert E
authors.initials: RE
authors.lastname: Martell
authors.forename: Kyle
authors.initials: K
authors.lastname: MacBeth
authors.forename: Anas
authors.initials: A
authors.lastname: Younes
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D001549:Benzamides / Q000494:pharmacology*; D001897:Boronic Acids / Q000494:pharmacology; D000069286:Bortezomib; D016207:Cytokines / Q000096:biosynthesis / Q000235:genetics; D004354:Drug Screening Assays, Antitumor / Q000379:methods; D004357:Drug Synergism; D020869:Gene Expression Profiling / Q000379:methods; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D000073864:Histone Deacetylase 6; D056572:Histone Deacetylase Inhibitors / Q000494:pharmacology*; D006655:Histone Deacetylases / Q000502:physiology; D006689:Hodgkin Disease / Q000473:pathology*; D006801:Humans; D016328:NF-kappa B / Q000378:metabolism; D011480:Protease Inhibitors / Q000494:pharmacology; D011719:Pyrazines / Q000494:pharmacology; D011743:Pyrimidines / Q000494:pharmacology*; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis / Q000235:genetics; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D000970:Antineoplastic Agents; D001549:Benzamides; D001897:Boronic Acids; D016207:Cytokines; D056572:Histone Deacetylase Inhibitors; D016328:NF-kappa B; D011480:Protease Inhibitors; D011719:Pyrazines; D011743:Pyrimidines; D014409:Tumor Necrosis Factor-alpha; D000069286:Bortezomib; C523184:mocetinostat; C433811:HDAC6 protein, human; D000073864:Histone Deacetylase 6; D006655:Histone Deacetylases