Non-thermal plasma inhibits tumor growth and proliferation and enhances the sensitivity to radiation in vitro and in vivo

Cancer is a major disease currently endangering the entire world population. Morbidity and mortality have increased substantially during recent decades. Radiotherapy is a primary treatment for malignant tumors, however side-effects and tumor cell resistance to ionizing radiation reduce the efficacy of radiotherapy. In recent years, non-thermal plasma (NTP) technology been used to treat cancer. In this study, we investigated the toxic effects of NTP on normal cells and tumor cells. We explored the inhibitory effect of NTP on tumor cell proliferation and evaluated the radiation-sensitizing effects of NTP on tumor cells and its mechanisms. In short, we examined the effect of NTP-combined radiation on proliferation, the cell cycle, apoptosis and DNA damage in normal and cancer cells. We found that NTP inhibited proliferation and induced apoptosis in tumor cells. NTP was more lethal to tumor cells than to normal cells. We found promising synergies of NTP with radiotherapy on cancer cells owing to their combined cytotoxic effects by generating ROS, inducing cell cycle arrest and apoptosis. NTP may be a new candidate for the treatment of cancer.