title: Antitumor activity of nifurtimox is enhanced with tetrathiomolybdate in medulloblastoma.
abstract: Medulloblastoma, a neuroectodermal tumor arising in the cerebellum, is the most common brain tumor found in children. We recently showed that nifurtimox induces production of reactive oxygen species (ROS) and subsequent apoptosis in neuroblastoma cells both in vitro and in vivo. Tetrathiomolybdate (TM) has been shown to decrease cell proliferation by inhibition of superoxide dismutase-1 (SOD1). Since both nifurtimox and TM increase ROS levels in cells, we investigated whether the combination of nifurtimox and TM would act synergistically in medulloblastoma cell lines (D283, DAOY). Genome-wide transcriptional analysis, by hybridizing RNA isolated from nifurtimox and TM alone or in combination treated and control cells (D283) on Affymetrix exon array gene chips was carried out to further confirm synergy. We show that nifurtimox and TM alone and in combination decreased cell viability and increased ROS levels synergistically. Examination of cell morphology following drug treatment (nifurtimox + TM) and detection of caspase-3 activation via Western blotting indicated that cell death was primarily due to apoptosis. Microarray data from cells treated with nifurtimox and TM validated the induction of oxidative stress, as many Nrf2 target genes (HMOX1, GCLM, SLC7A11 and SRXN1) (p<10(-5)) were upregulated. Other genes related to apoptosis, oxidative stress, DNA damage, protein folding and nucleosome formation were differentially involved in cells following treatment with nifurtimox + TM. Taken together, our results suggest nifurtimox and TM act synergistically in medulloblastoma cells in vitro, and that this combination warrants further studies as a new treatment for medulloblastoma.
authors.affiliation: Vermont Cancer Center, University of Vermont College of Medicine, Burlington, VT, USA.
authors.forename: Karen S
authors.initials: KS
authors.lastname: Koto
authors.forename: Pamela
authors.initials: P
authors.lastname: Lescault
authors.forename: Laurent
authors.initials: L
authors.lastname: Brard
authors.forename: Kyukwang
authors.initials: K
authors.lastname: Kim
authors.forename: Rakesh K
authors.initials: RK
authors.lastname: Singh
authors.forename: Jeff
authors.initials: J
authors.lastname: Bond
authors.forename: Sharon
authors.initials: S
authors.lastname: Illenye
authors.forename: Marni A
authors.initials: MA
authors.lastname: Slavik
authors.forename: Takamaru
authors.initials: T
authors.lastname: Ashikaga
authors.forename: Giselle L
authors.initials: GL
authors.lastname: Saulnier Sholler
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D045744:Cell Line, Tumor; D002528:Cerebellar Neoplasms / Q000188:drug therapy* / Q000473:pathology; D004249:DNA Damage; D004357:Drug Synergism; D006801:Humans; D008527:Medulloblastoma / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D008982:Molybdenum / Q000494:pharmacology*; D051267:NF-E2-Related Factor 2 / Q000502:physiology; D009547:Nifurtimox / Q000494:pharmacology*; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D051267:NF-E2-Related Factor 2; C495635:NFE2L2 protein, human; D017382:Reactive Oxygen Species; D008982:Molybdenum; C020809:tetrathiomolybdate; D009547:Nifurtimox