Abstract
Cold atmospheric plasmas (CAPs) have been proposed as a novel therapeutic method for its anti-cancer potential. However, its biological effects in combination with other physical modalities remain elusive. Therefore, this study examined the effects of cold atmospheric helium plasma (He-CAP) in combination with hyperthermia (HT) 42 °C or radiation 5 Gy. Synergistic enhancement in the cell death with HT and an additive enhancement with radiation were observed following He-CAP treatment. The synergistic effects were accompanied by increased intracellular reactive oxygen species (ROS) production. Hydrogen peroxide (H2O2) and superoxide (O2•–) generation was increased immediately after He-CAP treatment, but fails to initiate cell death process. Interestingly, at late hour’s He-CAP-induced O2•– generation subsides, however the combined treatment showed sustained increased intracellular O2•– level, and enhanced cell death than either treatment alone. He-CAP caused marked induction of ROS in the aqueous medium, but He-CAP-induced ROS seems insufficient or not completely incorporated intra-cellularly to activate cell death machinery. The observed synergistic effects were due to the HT effects on membrane fluidity which facilitate the incorporation of He-CAP-induced ROS into the cells, thus results in the enhanced cancer cell death following combined treatment. These findings would be helpful when establishing a therapeutic strategy for CAP in combination with HT or radiation.
Highlights
Cancer is still the leading cause of deaths worldwide, with increasing incidence because of changing lifestyle and increased exposure to carcinogens[1]
The results showed that the percentage of apoptotic cells induced by He-Cold atmospheric plasmas (CAPs) and HT treatment alone were less than 10%, when cells were exposed to combined treatment; it was increased to 22.5% and 45.5% with 120 s and 180 s, respectively
The efficacy of combined treatment was evaluated at longer time period; cell survival was assayed by CCk-8 following combined treatment at 24 h, as shown in Supplementary Fig. S1A, the cell survival after HT treatment alone was 94% ± 7.8, with combined treatment it declined to 66% ± 6.7 and 16% ± 2.0, with helium cold atmospheric plasma (He-CAP) 120 s and 180 s, respectively, showing synergistic enhancement in the cell death
Summary
Cancer is still the leading cause of deaths worldwide, with increasing incidence because of changing lifestyle and increased exposure to carcinogens[1]. The effects of CAP on other physical modalities such as hyperthermia (HT) and radiation has not been studied yet Both HT and radiation are known anti-cancer therapies, the impact of HT and radiation alone or in combination have been well documented[20]. Both therapies have been associated with un-intended effects because of exposure to high temperatures and radiation doses. In this study the effects of helium cold atmospheric plasma (He-CAP) were investigated on HT 42 °C or low dose radiation 5 Gy and described the molecular insight involved in the combined treatment using human myelomonocytic lymphoma U937 cells
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
