Induction of apoptosis by cold atmospheric pressure plasma for oral squamous cell carcinoma cells

Cold atmospheric pressure plasma (CAPP) techniques have developed rapidly during the last decades and have become an important field in plasma medicine. Plasma is ionized gas that is comprised of reactive atoms, molecules, ions, and radicals. CAPP generates various types of highly reactive oxygen and nitrogen species at room temperature that play an important part in biological applications including cancer therapy. In recent years, CAPP has gained increasingly more interest among cancer researchers, but the mechanism of CAPP’s effect is not fully understood. The aim of this study is to investigate both the mechanism of CAPP on oral squamous cell carcinoma (OSCC) cells as well as plasma-induced radicals. We observe plasma-induced highly reactive species in a plasma plume and cell culture. A cell proliferation assay shows that CAPP significantly decreases proliferation of oral squamous cells in vitro. Western blot analysis shows cleavage of poly (ADP-ribose) polymerase protein after plasma treatment, indicating that CAPP can induce cell death via the apoptosis pathway. These findings show that CAPP could be used as an alternative adjuvant therapeutic tool for the treatment of OSCC.