EXTH-61. COMBINATION OF DISULFIRAM AND COPPER INDUCES NPL4 AGGREGATION, TARGETS CD133-NESTIN CELLS AND EXTENDS SURVIVAL IN MEDULLOBLASTOMA GROUP 3 MODELS. (9th November 2020)

• Record Type: Journal Article
• Authors: Serra, Riccardo; Zhao, Tianna; Huq, Sakibul; Gorelick, Noah; Casaos, Joshua; Cecia, Arba; Mangraviti, Antonella; Olivi, Alessandro; Brem, Henry; Jackson, Eric M; Tyler, Betty
• Is Part Of: Neuro-oncology. Volume 22(2020)Supplement 2
• Page Start: ii100
• Page End: ii100
• Publication Date: 2020-11-09
• Subjects: Brain Neoplasms -- Periodicals; Brain -- Tumors -- Periodicals; Brain -- Cancer -- Periodicals; Nervous system -- Cancer -- Periodicals; 616.99481
• DOI: 10.1093/neuonc/noaa215.415
• Languages: English
• ISSNs: 1522-8517

Abstract

Abstract: BACKGROUND: Medulloblastoma (MB), the most common brain malignancy among children, is classified into four molecular subtypes, WNT-driven, Shh-driven, Group 3 and 4. The aim of this study was to assess the effects of the combination of Disulfiram, an inhibitor of Aldehyde Dehydrogenase, and Copper in Shh-driven and Group 3 MB, in vitro and in vivo . METHODS: The mechanisms of action and anti-cancer stem-cell effects of disulfiram were evaluated with clonogenic assays, flow-cytometry (FC), western blotting (WB), and immunofluorescence (IF) using established MB cell-lines - ONS76, UW228, D425med, D341 and D283- representing the main molecular subtypes. Survival, tumor volume, nuclear protein localization protein-4-expression (NPL4) and markers of proliferation/apoptosis were assessed in multiple models of Group 3 MB in vivo and ex vivo with WB and immunohistochemistry (IHC). RESULTS: Significant in vitro cytotoxicity was demonstrated at nanomolar concentrations of DSF in all lines. DSF/Cu ++ induced cell death (increased AnnV/PI, cleaved-Poly(ADP-ribose)polymerase fraction, and Apoptosis Inducing Factor on WB/FC/IF, in vitro and ex vivo ) through NPL4 accumulation in cell nucleus and intracellular buildup of poly-ubiquitylated proteins. DNA damage was also detected with WB and H2AX foci on immunofluorescence. Flow-cytometry analysis demonstrated a significant reduction in ALDH, Nestin- and CD133-positive cells in Group 3 lines, confirmed with WB in vitro and ex vivo . DSF/Cu ++ -toxicity was tested in vivo in multiple dose-escalating trials, and the combination significantly prolonged survival and reduced tumor volume in D425 and D341 xenografts. IHC showed lower Ki67 and increased Cleaved-Caspase-3 expression, higher NPL4-positive cells and no difference in NeuN and GFAP-positive cells after treatment. CONCLUSIONS: DSF/Cu ++ demonstrated a potent therapeutic effect on Shh-driven and Group 3 MB cell lines by determining apoptosis, targeting cancer stem cells and inducing DNA damage. Our data suggest that this combination may serve as a novel treatment, alone or with existing therapies, for pediatric MB.