Liquid Plasma Induces Necroptosis Without Inflammatory Responses in Head and Neck Cancer Cells.

Background: Several types of regulated cell deaths are known, including apoptosis, necroptosis, autophagy, ferroptosis, and pyroptosis. Among these types of cell deaths, apoptosis is induced by many cancer therapeutic agents. In the case of resistance, however, induction of other regulated cell death, such as necroptosis, are required. Liquid plasma, which is prepared by treatment of non-thermal plasma to solution, induces various types of regulated cell death via reactive oxygen and nitrogen species. Methods: Liquid plasma was generated by N Results: Here, we determined the type of cell death induced by liquid plasma in head and neck cancer (HNC) cells. Our results show that liquid plasma caused necroptosis in HNC cells, and peroxynitrite in the liquid plasma might be involved in the cell death. The expression of inflammation-related molecules, including nuclear factor kappa B (NF-κB), interleukin (IL)-6, and mitochondrial antiviral signaling proteins, were detected in HNC cells, and treatment of HNC cells with liquid plasma decreased their expression. Conclusions: These results suggest that liquid plasma could be used to treat HNC by inducing necroptosis without inflammatory responses. In this study, we demonstrated that liquid plasma treatment may kill HNC cells without causing necroptosis-induced inflammation and inflammation-mediated diseases.