Quantifying Biophoton Emissions From Human Cells Directly Exposed toLow-Dose Gamma Radiation

摘要

Biophoton emission leading to bystander effects (BEs) was shown inbeta-irradiated cells; however, technical challenges precluded the analysis ofthe biophoton role in gamma-induced BEs. The present work was to design anexperimental approach to determine if, what type, and how many biophotons couldbe produced in gamma-irradiated cells. Photon emission was measured in HCT116p53 cells irradiated with a total dose of 22 mGy from acesium-137 source at a dose rate of 45 mGy/min. A single-photon detection unitwas used and shielded with lead to reduce counts from stray gammas reaching thedetector. Higher quantities of photon emissions were observed when the cells ina tissue culture vessel were present and being irradiated compared to acell-free vessel. Photon emissions were captured at either 340 nm (in theultraviolet A [UVA] range) or 610 nm. At the same cell density, radiationexposure time, and radiation dose, HCT116 p53 cells emitted 2.5times more UVA biophotons than 610-nm biophotons. For the first time, gammaradiation was shown to induce biophoton emissions from biological cells. Ascellular emissions of UVA biophotons following beta radiation lead to BEs, theinvolvement of cellular emissions of the same type of UVA biophotons in gammaradiation-induced BEs is highly likely.