Mechanisms of Selective Antitumor Action of Cold Atmospheric Plasma-Derived Reactive Oxygen and Nitrogen Species

Transformed cells are subject to elimination through intercellular reactive oxygen/nitrogen species (RONS)-dependent apoptosis-inducing signaling. Tumor progression, therefore, requires expression of membrane-bound catalase. Recent research demonstrates that ¹O₂ can inactivate membrane-bound catalase, thus, inducing the generation of tumor cell-derived secondary ¹O₂ and RONS-dependent apoptosis selectively in tumor cells. Crucially, ¹O₂ signaling can result in self-perpetuating apoptotic signaling from cell-to-cell. It is known that CAP contains ¹O₂ and that certain CAP constituents can generate ¹O₂ in solution. The analysis of model experiments performed with defined RONS implies that CAP-derived ¹O₂ induces the mechanism through which CAP acts selectively against cancer cells in vitro and tumors in vivo. This hypothesis needs to be tested experimentally in order to establish its validity.