Effects of cold atmospheric plasma on solid tumors in ovo - An exploratory study using the HET Cam model

Introduction Cold atmospheric plasma (CAP) is ionized gas consisting of ionized Atoms, radicals, photons as well as electromagnetic radiation. Several in vitro and in vivo studies suggest inhibiting effects of CAP on mitosis of malignant cells as well as tumor growth by induction of DNA damage and apoptosis.Some authors have described a selectivity of these effects on malignant cells.

Aims The tolerability of CAP therapy as well as the effects of therapy with CAP on solid tumors were investigated by exposing solid tumors in the Hens Egg Chorion Allantoic Membrane (CAM) assay with a varying duration of treatment.

Methods Chicken eggs were randomized to 5 experimental groups of ~60 individuals per cycle after ingrowth of a solid tumor (HuH7) into the CAM. Subsequently, depending on the experimental group, the CAM was irradiated with CAP using a cumulative irradiation time of 240 s/180 s/120s/60s or 0s with irradiation cycles of 60s per day. The survival rates of the chicken eggs as well the tumor size determined by ultrasonography in ovo were quantified. After fixation of the CAM and immunohistochemistry, the rate of apoptosis was quantified in histological slides.

Results The survival analysis of the experimental groups shows a decreasing survival rate of chicken embryos with increasing CAP exposure. The determined rate of apoptosis within tumor tissue was altered compared to the control group. No correlation between tumor size and duration of CAP exposure could be observed. However, solid tumors were heterogeneous regarding size and depth of ingrowth into the CAM.

Conclusion CAP could provide an additive to established treatment options by increasing the rate of apoptosis in solid tumors. However, systemic side effects of CAP therapy have to be further investigated.

Poster-PDF A-1481.PDF

Publication History

Article published online:
10 June 2020