title: The novel inhibitor of histone deacetylase resminostat (RAS2410) inhibits proliferation and induces apoptosis in multiple myeloma (MM) cells.
abstract: Inhibition of histone deacetylase (HDAC) is a promising mechanism for novel, anti-myeloma agents. We investigated the effects of the novel HDAC inhibitor resminostat on multiple myeloma (MM) cells in vitro. Resminostat is a potent inhibitor of HDACs 1, 3 and 6 [50% inhibitory concentration (IC50)=43-72 nmol/l] representing HDAC classes I and II and induces hyperacetylation of histone H4 in MM cells. Low micromolar concentrations of resminostat abrogated cell growth and strongly induced apoptosis (IC50=2.5-3 micromol/l in 3 out of 4 MM cell lines) in MM cell lines as well as primary MM cells. At 1 micromol/l, resminostat inhibited proliferation and induced G0/G1 cell cycle arrest in 3 out of 4 MM cell lines accompanied with decreased levels of cyclin D1, cdc25a, Cdk4 and pRb as well as upregulation of p21. Resminostat decreased phosphorylation of 4E-BP1 and p70S6k indicating an interference with Akt pathway signalling. Treatment with resminostat resulted in increased protein levels of Bim and Bax and decreased levels of Bcl-xL. Caspases 3, 8 and 9 were activated by resminostat. Furthermore, synergistic effects were observed for combinations of resminostat with melphalan and the proteasome inhibitors bortezomib and S-2209. In conclusion, we have identified potent anti-myeloma activity for this novel HDAC inhibitor.
authors.affiliation: Department of Haematology and Oncology, Medizinische Klinik Innenstadt, Klinikum der Universität München (LMU), Munich, Germany.
authors.forename: Sonja
authors.initials: S
authors.lastname: Mandl-Weber
authors.forename: Felix G
authors.initials: FG
authors.lastname: Meinel
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Jankowsky
authors.forename: Fuat
authors.initials: F
authors.lastname: Oduncu
authors.forename: Ralf
authors.initials: R
authors.lastname: Schmidmaier
authors.forename: Philipp
authors.initials: P
authors.lastname: Baumann
mesh_terms: D000107:Acetylation / Q000187:drug effects; D000970:Antineoplastic Agents / Q000494:pharmacology*; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D049109:Cell Proliferation / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D056572:Histone Deacetylase Inhibitors / Q000494:pharmacology*; D006657:Histones / Q000378:metabolism; D006801:Humans; D006877:Hydroxamic Acids / Q000494:pharmacology*; D009101:Multiple Myeloma / Q000378:metabolism / Q000473:pathology*; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D013449:Sulfonamides / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
chemical_list: D000970:Antineoplastic Agents; D056572:Histone Deacetylase Inhibitors; D006657:Histones; D006877:Hydroxamic Acids; D019253:Proto-Oncogene Proteins c-bcl-2; D013449:Sulfonamides; C550599:resminostat; D051057:Proto-Oncogene Proteins c-akt