Non-thermal Ionized Plasma Induction of Pre-programmed Cell Death in Acute Monocytic Leukemia Cells

In physics and chemistry, plasma is a state of matter similar to gas in which a certain portion of the particles are ionized which can be a thermal or non-thermal form. Ionized plasma has many applications, such as for sterilization, tissue removal, and cauterization of blood vessels to stop bleeding.  Ionized plasma is already being seen used in the medical field which leads to the possibility of using non-thermal ionized plasma to help in the fight against cancer.  The hypothesis of this research is non-thermal plasma mediates cancer cells to undergo a non-inflammatory process of preprogrammed cell death. In our experiments, we specifically reviewed apoptosis and autophagy. The results indicate that varying plasma experimental parameters and treatment procedures, the nonthermal plasma can induce preprogrammed cell death in cancer cells. By varying the distance and time of exposure, the induction of apoptosis or autophagy in acute monocytic leukemia cells (THP-1) is observed.  Apoptotic cells were identified using fluorescent dye conjugated annexin V. Autophagy induction was observed through FITC-labeled anti-LC3.  Fluorescent imaging revealed that lower treatment doses are capable of inducing programmed cellular death.  The majority of our observations with non-thermal plasma treatment of THP-1 cells pose apoptosis as the primary response; however, autophagy needs to be further explored to identify distinctive phenotypes. Ideally the results obtained from these experiments will allow for further investigation of the effects of ionized non-thermal plasma on other cancer cells and lead to an inexpensive method for treating cancer.