Miniature Non-thermal Plasma Induced Cell Cycle Arrest and Apoptosis in Lung Carcinoma Cells

Abstract

Non-thermal plasma has been a promising new cancer treatment modality in plasma oncology field. It generates extracellular and intracellular reactive species which are key factors for the treatment of cancer cells. In this study, we investigated the differential effect of non-thermal plasma on both A549 lung adenocarcinoma and MRC-5 lung fibroblast cells. Extracellular generation of reactive species in both A549 lung cancer and MRC-5 normal lung fibroblast cells were similar, whereas intracellular penetration of reactive species generated by plasma in A549 cancer cells were almost fourfold higher than the normal cells. Interestingly, A549 cancer cells treated for shorter (15 and 30 s) and longer durations (60 and 120 s) get arrested in S-phase (19%) and G2/M phase (28%) respectively. In a healthy MRC-5 cells, few cells arrested in S and G2/M phase in relative to A549 cells for all treatment time. Finally, we evaluated the expression of apoptosis-related genes, H2AX, BAX, P53, Caspase-8, and ATM on normal and cancer cells. There was a higher expression of BAX gene for 120 s plasma treated A549 cell samples at day 1 relative to MRC-5 cells. These findings demonstrate that non-thermal plasma generated reactive species creates intracellular stress, that arrests cell cycle and induces apoptosis in cancer cells. This study suggests that non-thermal plasma could be a potential therapy for lung cancer treatment.