(143e) Investigating the Effects of Cold Atmospheric Plasma on Cervical Cancer

Evidence indicates that cold atmospheric plasma (CAP) may selectively induce apoptosis in cancerous cells. Due to these observed selective effects, the use of CAP is a promising new avenue for cancer therapy. Despite its potential impact, the effects of CAP in biological systems are not well understood. This project investigates the cellular and molecular responses induced by CAP treatment within cancerous (SiHa) and non-cancerous (Ect1/E6E7 and End1/E6E7) cervical cell lines, in vitro, in order to better understand the viability of CAP as a therapy for cervical cancer. Cervical cancer is the fourth most common cancer in women, and it was recently revealed that its impact has been historically grossly underestimated. Its prevalence and accessibility for topical treatment make cervical cancer an ideal target for CAP treatments.

Plasma is a state of ionized gas, often considered the fourth state of matter; it is produced using a strong, controlled electric field or extreme heat. CAP, however, is a subset of plasma that is not in thermodynamic equilibrium. This allows for electron temperatures that are necessary to achieve ionization, while the bulk plasma temperature remains below 40^oC. Because of the non-thermal nature of this type of plasma, biological systems are able to be exposed to CAP treatments without heating-induced effects.

A floating electrode dielectric barrier discharge (FE-DBD) plasma pen was developed for this study in order to investigate the cellular and molecular responses induced by CAP in cervical cells. The CAP was produced with 98% argon, 2% oxygen carrier gas mixture at a flowrate of 2 L/m. Standard CAP treatment for this investigation was produced with 10kV, 0.1A, and the cells were treated for 30 seconds.

After exposure to standard CAP treatment, 71 ± 7% of cancerous cells underwent apoptosis as indicated by flow cytometric analysis with Annexin V and propidium iodide staining protocols (n=3). One hypothesized cause of CAP induced apoptosis is through CAP alteration of the cellular membrane, allowing for plasma produced ions, such as reactive oxygen and nitrogen species (RONS), to enter the cell more easily. Indication of membrane alteration was observed in the cancerous and non-cancerous cervical cell lines. All of the cell lines had altered levels and locations of uptake of FITC and quantum dots following CAP treatment as compared to carrier gas treatment controls. Altering membrane permeability may be an important mechanism through which CAP treatment increases intercellular exposure to apoptotic triggers. Thus, while altering the membrane permeability in a controlled and selective manner could allow CAP treatment to be used to target for delivery of imaging dyes and small molecule compounds.

In conclusion, developing a comprehensive understanding of CAP effects on cancerous and non-cancerous cells could lead to the development of effective therapeutic interventions for cervical cancer.