A key inactivation factor of HeLa cell viability by a plasma flow

Abstract

Recently, a plasma flow has been applied to medical treatment using effects of various kinds of stimuli such as chemical species, charged particles, heat, light, shock wave and electric fields. Among them, the chemical species are known to cause an inactivation of cell viability. However, the mechanisms and key factors of this event are not yet clear. In this study, we focused on the effect of H2O2 in plasma-treated culture medium because it is generated in the culture medium and it is also chemically stable compared with free radicals generated by the plasma flow. To elucidate the significance of H2O2, we assessed the differences in the effects of plasma-treated medium and H2O2-added medium against inactivation of HeLa cell viability. These two media showed comparable effects on HeLa cells in terms of the survival ratios, morphological features of damage processes, permeations of H2O2 into the cells, response to H2O2 decomposition by catalase and comprehensive gene expression. The results supported that among chemical species generated in a plasma-treated culture medium, H2O2 is one of the main factors responsible for inactivation of HeLa cell viability.

Effectiveness of plasma treatment on gastric cancer cells

“…Our results support this and other hypotheses that attributed the cytotoxic effects of plasma to apoptosis resulting from ROS uptake into tumor cells [14,26]. Only SC-2-NU cells showed an inverse result.…”

“…In recent years, several therapeutic trials have been completed in the fields of tissue sterilization, blood coagulation, wound-healing promotion, and dental bleaching [11][12][13]. Additionally, it has been reported that plasma can exert antiproliferative effects on various cancer cell lines, possibly through induction of apoptosis [6,14,15]. Ultimately, it could develop into a treatment option alongside conventional cytotoxic agents or radiotherapy in the field of oncology [6].…”

Gene expression responses of HeLa cells to chemical species generated by an atmospheric plasma flow

“…In order to elucidate the interference mechanism between the plasma flow and cells, analysis of the cellular response at the level of gene expression is important. In the present study, we assessed the response of HeLa cells to a culture medium exposed to plasma for 40 s, a much shorter time than in the previous study [18]. Different from our previous study [18], this irradiation level allows the cells to survive without apparent induction of necrosis.…”

“…In the present study, we assessed the response of HeLa cells to a culture medium exposed to plasma for 40 s, a much shorter time than in the previous study [18]. Different from our previous study [18], this irradiation level allows the cells to survive without apparent induction of necrosis. The gene expression of HeLa cells was broadly analyzed by a DNA microarray in plasmatreated medium and H 2 O 2 -added medium as compared with expression in a regular culture medium.…”

“…We previously reported that chemical species generated in cell culture medium by irradiation with an atmospheric plasma flow for 210 s induced inactivation of HeLa cells and that H 2 O 2 , a representative ROS, was the main cause of this [18]. In order to elucidate the interference mechanism between the plasma flow and cells, analysis of the cellular response at the level of gene expression is important.…”