Cold Atmospheric Plasma as a Potential Chordoma Treatment

Abstract Cold atmospheric plasma (CAP) uses high voltages and helium or argon feed gases to generate and deliver atmospheric reactive oxygen or nitrogen species. Over the past decade, there has been an increasing number of successful demonstrations of CAP in oncology with anti-tumor effects demonstrated both in vitro and in vivo, including in glioma. Chordomas remain one of the most difficult-to-treat of the skull base tumors. The best chance of survival and cure to date is with radical surgical resection, followed by adjuvant radiation therapy. Oftentimes, tumor infiltration into functionally critical, or difficult-to-access areas, precludes radical resection. CAP has been shown to increase sensitivity to chemoradiation and could therefore be a useful tool in improving chordoma recurrence rates as an intraoperative adjuvant therapy to the current standard of care. To date, there are no studies in the literature examining the effect of CAP on chordomas. We treated UM-Chor1 chordoma cells with a plasma jet and measured cell viability and intracellular ROS production. Our experiments show a dose-dependent increase in intracellular ROS and cell death with direct CAP exposure in vitro. Further studies are needed to better determine the mechanisms of cell death and factors contributing to chordoma sensitivity to CAP.