Antitumor activity of nifurtimox is enhanced with tetrathiomolybdate in medulloblastoma
Karen S Koto1, Pamela Lescault, Laurent Brard
1Vermont Cancer Center, University of Vermont College of Medicine, Burlington, VT, USA.
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.
Insights
Nifurtimox and tetrathiomolybdate (TM) synergistically kill medulloblastoma cells by increasing reactive oxygen species (ROS) and inducing apoptosis. This combination therapy shows promise for treating pediatric brain tumors.
Area of Science:
- Oncology
- Molecular Biology
- Pharmacology
Background:
- Medulloblastoma is the most common pediatric brain tumor.
- Nifurtimox and tetrathiomolybdate (TM) individually increase reactive oxygen species (ROS) and induce apoptosis in cancer cells.
- The synergistic effect of nifurtimox and TM on medulloblastoma has not been previously investigated.
Purpose of the Study:
- To investigate the synergistic effect of nifurtimox and TM on medulloblastoma cell lines.
- To determine the mechanism of cell death induced by the combination therapy.
- To explore the potential of this combination as a novel treatment for medulloblastoma.
Main Methods:
- Medulloblastoma cell lines (D283, DAOY) were treated with nifurtimox and TM alone or in combination.
- Cell viability and ROS levels were measured.
- Apoptosis was assessed by examining cell morphology and caspase-3 activation.
- Genome-wide transcriptional analysis was performed using Affymetrix exon array gene chips.
Main Results:
- Nifurtimox and TM synergistically decreased medulloblastoma cell viability and increased ROS levels.
- Cell death was primarily mediated by apoptosis, confirmed by caspase-3 activation and morphological changes.
- Microarray analysis revealed upregulation of Nrf2 target genes involved in oxidative stress response (e.g., HMOX1, GCLM, SLC7A11, SRXN1).
- Genes related to apoptosis, DNA damage, and protein folding were differentially regulated.
Conclusions:
- Nifurtimox and TM act synergistically to induce apoptosis in medulloblastoma cells in vitro.
- The combination therapy effectively targets medulloblastoma by increasing oxidative stress.
- This nifurtimox and TM combination warrants further investigation as a potential new treatment strategy for medulloblastoma.
