Abstract
BACKGROUND
Treatment of glioblastoma multiforme (GBM) continues to remain a challenge using conventional treatment. Through an in vitro study we assessed the efficacy of our novel cold atmospheric plasma technology (CAP) to sensitize GBM cells to temozolomide (TMZ).
METHODS
The CAP jet is formed through the discharge (Pk-Pk: 5.8 kV) between a ring grounded cathode and a central anode and with He flow through a glass tube. The discharge process is driven by an AC high voltage (3.16 kV) with a frequency of 12.5 kHz. Human glioblastoma (U87MG) cells were cultured in DMEM supplemented by 1% (v/v) penicillin and streptomycin solution and 10% (v/v) FBS. CAP was delivered to U87 cells in a 96-well plate for 1 min in combination with 10 and 15 μM H2O2. The cell viability was measured by using the MTT assay. We then tested TMZ concentrations of 10 and 50 uM. Cell viability was monitored with the Cell Titer Glo 2.0. luminescent assay. All experiments were performed in triplicate and were independently repeated at least 3 times.
RESULTS
We identified an activation state of U87MG cells after the plasma treatment. This activation state resulted in GBM cells sensitized to reactive species identified by decreased cell viability after treatment with H2O2 as compared to the H2O2 treatment alone (p< 0.005). In addition, the plasma-activated cells were sensitized to TMZ. Cells treated with CAP in combination with TMZ displayed decreased cell viability at TMZ concentrations of (10 uM) (p< 0.05) and (50 uM) (p< 0.005) as compared to TMZ alone.
CONCLUSIONS
This study demonstrates the activation phenomenon on GBM cells via direct CAP treatment. Due to this activation, the GBM cells were sensitized to both H2O2 and TMZ identified via decreased cell viability. Future work looks to assess this effect of cell activation/sensitization with chemotherapy plus radiation treatment.