Effectiveness of plasma treatment on gastric cancer cells

Abstract

Background Treatment of peritoneal carcinomatosis arising from gastric cancer remains a considerable challenge. In recent years, the anticancer effect of nonequilibrium atmospheric pressure plasma (NEAPP) has been reported in several cancer cell lines. Use of NEAPP may develop into a new class of anticancer therapy that augments surgery, chemotherapy, and radiotherapy. Method Gastric cancer cells were assessed for changes in cell morphology and rate of proliferation after treatment with NEAPP-exposed medium (PAM). To explore the functional mechanism, caspase 3/7, annexin V, and uptake of reactive oxygen species (ROS) were evaluated, along with the effect of the ROS scavenger N-acetylcysteine (NAC). Results PAM treatment for 24 h affected cell morphology, suggestive of induction of apoptosis. PAM cytotoxicity was influenced by the time of exposure to PAM, the type of cell line, and the number of cells seeded. Cells treated with PAM for 2 h demonstrated activated caspase 3/7 and an increased proportion of annexin V-positive cells compared with untreated cells. Additionally, ROS uptake was observed in PAM-treated cells, whereas NAC reduced the cytotoxicity induced by PAM presumably through reduction of ROS uptake. Furthermore, CD44 variant 9, which reportedly leads to glutathione synthesis and suppresses stress signaling of ROS, was overexpressed in PAM-resistant cells. Conclusions PAM treatment induced apoptosis of gastric cancer cells through generation and uptake of ROS. Local administration of PAM could develop into an option to treat peritoneal carcinomatosis.

Non-thermal atmospheric pressure plasma activates lactate in Ringer’s solution for anti-tumor effects

“…Cold plasma affects biological targets not only directly but also indirectly through the medium, which has broadened the potential applications of non-thermal atmospheric pressure plasma in medicine41424344454647484950. We have demonstrated that plasma-irradiated medium, also called plasma-activated medium (PAM), has anti-tumor effects against glioblastoma5152, as well as ovarian5354, gastric55, pancreatic56, and lung cancer cells57. Plasma interacts with oxygen, nitrogen, and water in air to produce various radicals, such as hydroxyl radicals and nitric oxide.…”

Reduced HeLa cell viability in methionine‐containing cell culture medium irradiated with microwave‐excited atmospheric‐pressure plasma

“…This type of selective targeting of cancer cells is ideally suited to cancer therapy. An antitumor effect of PAM treatment has been reported for a broad range of cancer and cancer cell types . Details regarding the intracellular molecular mechanism of cell death in cancers treated with PAM and the interaction of PAM with cells were reported by Tanaka et al PAM treatment was found to downregulate the kinase activity of both AKT and ERK in the PI3K/AKT signaling pathway, as well as the Ras/MAPK signaling pathway, in glioblastoma brain tumor cells .…”

Aqueous Plasma Pharmacy: Preparation Methods, Chemistry, and Therapeutic Applications

“…Another 2015 study considered the impact of PAM on the cell morphology and proliferation rate of gastric cancer cells. 101 The impact on cancer cells was dependent upon plasma exposure time during PAM preparation, the cell line, and the initial cell concentration. Some cell lines were more resistant to PAM treatment, but this could be overcome by increasing the plasma treatment time during preparation.…”