Pyruvate Plays a Main Role in the Antitumoral Selectivity of Cold Atmospheric Plasma in Osteosarcoma

Juan Tornin,Miguel Mateu-Sanz,Cédric Labay,Aida Rodríguez,Cristina Canal,Rene Rodríguez

doi:10.1038/s41598-019-47128-1

Abstract

Osteosarcoma (OS) is the most common primary bone tumor but current therapies still have poor prognosis. Cold Atmospheric Plasma (CAP) and Plasma activated media (PAM) have shown potential to eliminate cancer cells in other tumors. It is thought that Reactive Oxygen and Nitrogen species (RONS) in PAM are key players but cell culture media composition alters treatment outcomes and data interpretation due to scavenging of certain RONS. In this work, an atmospheric pressure plasma jet was employed to obtain PAM in the presence or absence of pyruvate and used to treat the SaOS-2 (OS) cell line or hBM-MSC healthy cells. OS cells show higher sensitivity to PAM treatment than healthy cells, both in medium with and without pyruvate, activating apoptosis, DNA damage and deregulating cellular pathways mediated by c-JUN, AKT, AMPK or STAT3. In line with previous works, lack of pyruvate increases cytotoxic potential of PAM affecting cancer and healthy cells by increasing 10–100 times the concentration of H2O2 without altering that of nitrites and thus decreasing CAP anti-tumor selectivity. Suitable conditions for CAP anti-cancer selectivity can be obtained by modifying plasma process parameters (distance, flow, treatment time) to obtain adequate balance of the different RONS in cell culture media.

Highlights

The effects of different plasma-activated liquids, including cell culture media, have been evaluated[35]
Different plasma treatment conditions of Plasma Activated Media (PAM) with/without pyruvate were evaluated on the cytotoxicity of PAM, and mechanistic insights were investigated by studying cell proliferation, DNA damage, cell death mechanisms and cell signaling on osteosarcoma and non-cancer cells
Optical Emission Spectroscopy (OES) was used to analyze the species generated by plasma in gas phase (Fig. 1)

Summary

Introduction

The effects of different plasma-activated liquids, including cell culture media, have been evaluated[35]. Exhaustive determination of all RONS present in PAM is far from straightforward, and the most often quantified species are hydrogen peroxide, nitrites and nitrates It is known, that a much more complex cocktail of species is formed in PAM through diffusion from the gas phase to the liquid. Adachi et al, showed that cell culture media composition determines PAM cytotoxic potential on cancer cells, and Pyr reduces cell damage on cancer cells[48]. Different plasma treatment conditions of PAM (distance, gas flow, treatment time) with/without pyruvate were evaluated on the cytotoxicity of PAM, and mechanistic insights were investigated by studying cell proliferation, DNA damage, cell death mechanisms and cell signaling on osteosarcoma and non-cancer cells

Methods

Results

Discussion

Conclusion