title: Anti-leukemia activity of MS-275 histone deacetylase inhibitor implicates 4-1BBL/4-1BB immunomodulatory functions.
abstract: Histone deacetylase inhibitors (HDACi) have demonstrated promising therapeutic potential in clinical trials for hematological malignancies. HDACi, such as SAHA/Vorinostat, Trichostatin A, and MS-275 were found to induce apoptosis of leukemic blasts through activation of the death receptor pathway and transcriptional induction of the Tumor Necrosis Factor (TNF)-related pro-apoptotic family members, TRAIL and FasL. The impact of HDACi on TNF-related costimulatory molecules such as 4-1BB ligand (4-1BBL/TNFSF9) is however not known. Following exposure to SAHA/Vorinostat, Trichostatin A, and MS-275, transcript levels were determined by real time PCR in Jurkat, Raji and U937 cells. Treatment with HDACi up-regulated TNFSF9 gene expression in the three leukemia cell lines, yet to different extend and with distinct kinetics, which did not require de novo protein synthesis and was not associated with DNAse I hypersensitive chromatin remodeling. Transcriptional activity of TNFSF9 promoter-luciferase constructs was induced up to 12 fold by HDACi, and implication of Sp1/Sp3 transcription factors binding to functional GC-box elements was evidenced by reporter gene assays, site-directed mutagenesis, and electrophoretic mobility shift assays. Functionality of modulated target genes was assessed in allogeneic mixed leukocyte reaction experiments. MS-275- and to a lesser extent Trichostatin A- and SAHA-treated Raji cells significantly up regulated T lymphocytes proliferation which was reduced by about 50% by a 4-1BB blocking recombinant protein, while MS-275- but neither Trichostatin A- nor SAHA-treated cells up-regulated IFNgamma secretion by T lymphocytes. Our results identify 4-1BBL/4-1BB as a downstream target of HDACi, especially of MS-275 anti-leukemia action in vitro. Thus, HDACi such as MS-275 displaying dual TNF-dependent proapoptotic and costimulatory activities might be favored for inclusion in HDACi-based anti-cancer therapeutic strategies.
authors.affiliation: INSERM U891, Centre de Recherche en Cancérologie de Marseille, Marseille, France.
authors.forename: Bérengère
authors.initials: B
authors.lastname: Vire
authors.forename: Stéphane
authors.initials: S
authors.lastname: de Walque
authors.forename: Audrey
authors.initials: A
authors.lastname: Restouin
authors.forename: Daniel
authors.initials: D
authors.lastname: Olive
authors.forename: Carine
authors.initials: C
authors.lastname: Van Lint
authors.forename: Yves
authors.initials: Y
authors.lastname: Collette
mesh_terms: D053330:4-1BB Ligand / Q000378:metabolism*; D000970:Antineoplastic Agents / Q000494:pharmacology*; D001549:Benzamides / Q000494:pharmacology*; D049109:Cell Proliferation; D015973:Gene Expression Regulation, Leukemic; D006801:Humans; D006877:Hydroxamic Acids / Q000494:pharmacology; D007107:Immune System / Q000187:drug effects*; D019169:Jurkat Cells; D007938:Leukemia / Q000188:drug therapy*; D016297:Mutagenesis, Site-Directed; D011725:Pyridines / Q000494:pharmacology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013601:T-Lymphocytes / Q000378:metabolism; D053261:Tumor Necrosis Factor Receptor Superfamily, Member 9 / Q000378:metabolism*; D020298:U937 Cells
chemical_list: D053330:4-1BB Ligand; D000970:Antineoplastic Agents; D001549:Benzamides; D006877:Hydroxamic Acids; D011725:Pyridines; D053261:Tumor Necrosis Factor Receptor Superfamily, Member 9; C118739:entinostat; C012589:trichostatin A