Bystander Effects Induced by the Monolayer and Three Dimensional Cultures Exposed to Ionizing Radiation

Abstract

Although monolayer cells culture model has played great role in the study of biological phenomena and mechanisms about bystander effect, three dimensional (3D) culture model is believed to be much more appropriate in mimicking the in vivo physiological processes. In this study, human lung bronchial epithelial cells were firstly cultured in both 3D and monolayer model, then irradiated by X-rays and high-LET carbon ions, and finally co-cultured with normal lung fibroblast cell. The bystander γH2AXfoci were found in both recipient fibroblast cells co-cultured with irradiated monolayer and 3D cells. It is of interest that significantly more bystander γH2AXfoci were induced by the monolayer cells than by the 3D cells after X-ray irradiation, while the numbers of bystander γH2AXfoci induced by both donor cells were comparative after carbon ion irradiation. Our results suggest that the magnitude of the bystander effect depended on the culture morphology and radiation quality.