Cold atmospheric plasma (CAP) has been suggested for use as a novel cancer therapeutic due to its reported ability to induce cell-specific death. Cervical cancer is the fourth most common cancer in women. Its prevalence and accessibility for topical treatment make cervical cancer an ideal target for CAP treatments. Despite its potential impact, effects of CAP in biological systems are not well understood. To better understand the viability of CAP as a therapy, this project investigated in vitro cellular responses induced by CAP treatment within cancerous cervical cells (SiHa) and non-cancerous cervical (Ect1/E6E7 and End1/E6E7) and vaginal cells (VK2/E6E7).
Plasma is a state of ionized gas, produced using a controlled electric field or extreme heat. CAP, however, is a subset of plasma that is produced near 1 atm and 40oC. This allows for CAP treatment of biological systems without heating-induced effects. A dielectric barrier discharge plasma pen was developed for this study. Plasma modeling was conducted in order to predict the reactive species present in the system. CAP treatments were performed on cells for 30 seconds using a helium carrier gas at a flowrate of 1 L/min and a DC power supply with input settings of 10kV, 1µs, and 0.1A.
Cell vitality assays demonstrated induced cell death following exposure to CAP treatment in both cancerous and noncancerous cervical cells as indicated by flow cytometric analysis and florescence microscopy. CAP treatment induced cell death in 76 ± 8% of treated cancerous, SiHa, cells. In comparison, noncancerous cell lines Ect1/E6E7, End1/E6E7, and VK2/E6E7 underwent 49 ± 8%, 42 ± 13%, and 51 ± 7% cell death, respectively. Flow cytometry characterization and wound healing assays indicate that CAP treatment does not significantly affect the expression of investigated cell surface adhesion molecules or cell migration. Cells were treated with helium carrier gas as the negative control and hydrogen peroxide as an induced death control.
Altered levels and locations of uptake of FITC and quantum dots following CAP treatment suggest modification of cell membranes as compared to carrier gas treatment controls. Adjustments in membrane permeability may be a mechanism through which CAP treatment increases exposure to apoptotic triggers.
In conclusion, comprehensive understanding of CAP effects on cancerous and non-cancerous cells could lead to the development of effective CAP-based therapies for cervical cancer.
Citation Format: Nicole J. Sova, Yonry Zhu, Quinn O. Mitchell, Ariel L. Lanier, David Burnette, Monica M. Burdick. Developing methods for investigating cold atmospheric plasma effects on cervical cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4390.