Response of the EPI-200 human 3-D skin model to high and low doses of protons

Accumulating data suggest that the biological responses to high and low doses of radiation are qualitatively different, necessitating the direct study of low dose responses. Most such studies have utilized 2-dimensional culture systems, which may not fully represent responses in 3-dimensional tissues. To gain insight into low dose responses in tissue, we have profiled global gene expression in EPI-200, a 3-dimensional tissue model from MatTek that imitates the structure and function of human epidermis, at 4, 16 and 24 hours after exposure to high (2.5 Gy) and low (0.1 Gy) doses of low LET protons. Untreated controls and samples exposed to 10 cGy or to 2.5 Gy were analyzed at three different times (4, 16 or 24 hours after exposure). Three biological repeats were performed for each condition