# Arsenic Trioxide and the MNK1 Inhibitor AUM001 Exert Synergistic Anti-Glioblastoma Effects by Modulating Key Translational, Cell Cycle, and Transmembrane Transport Pathways

## TL;DR

Combining arsenic trioxide with an MNK1 inhibitor shows stronger anti-cancer effects in glioblastoma by targeting key cellular processes.

## Contribution

A novel combination therapy using ATO and AUM001 is shown to synergistically target glioblastoma stem cells and overcome resistance.

## Key findings

- The ATO and AUM001 combination significantly reduces glioblastoma stem cells, especially in ATO-resistant models.
- Synergistic effects are linked to molecular signatures involving translation, cell cycle, and transmembrane transport pathways.
- Mesenchymal subtype glioblastoma models show greater sensitivity to the drug combination.

## Abstract

Background: The profound heterogeneity of glioblastoma and the often-limited efficacy of conventional treatments, including arsenic trioxide (ATO), underscore the urgent and critical demand for innovative combination strategies specifically designed to overcome treatment resistance. Methods: We evaluated the therapeutic effects of ATO as a single agent and in combination with the MNK1 inhibitor AUM001 across patient-derived xenograft (PDX) models and investigated molecular determinants of sensitivity and synergy. Our results demonstrated that GBM models resistant to ATO, particularly those of the mesenchymal subtype, are more likely to show synergistic cytotoxicity when AUM001 is added. The combination significantly reduces the frequency of glioblastoma stem cells (GSCs) compared to either drug alone, especially in ATO-resistant models. Results: These observations suggest that targeting the MNK1 pathway in conjunction with ATO is a promising strategy to specifically eradicate GSCs, which are major drivers of GBM recurrence and therapeutic failure. Transcriptomic analyses revealed that ATO sensitivity correlated with activated translation-related pathways and cell cycle processes, while synergistic responses to the combination were driven by distinct molecular signatures in different GBM subtypes. Overall, synergistic response to the combination therapy is more associated with cellular organization, amino acid transmembrane transporter activity, ion channels, extracellular matrix organization and collagen formation. Conclusions: Our findings highlight that specific molecular pathways and their activities, including those involving translation, cell cycle and ion transport, appear to modulate the synergistic efficacy of the ATO and AUM001 combination, thereby offering potential biomarkers for improved patient stratification in future GBM clinical trials of such ATO-based treatments.