Mechanism(S) of Three-Dimensional Intercellular Signaling in Mammary Epithelial Cells in Response to Low Dose, Low-LET Radiation: Implications for the Radiation-Induced Bystander Effect
Sponsor: DOE Office of Biological and Environmental Research Low Dose Radiation Research Program
Contact: Lee Opresko
This research makes use of novel imaging protocols for in situ visualization of 3D radiation-induced bystander signaling. It is now well established that radiation induced bystander effects (RIBE) can be evoked in vitro using cells in two-dimensional culture, however, entirely different types or levels of signaling may be occurring in three-dimensional systems. We will use model 3D mammary epithelial cell systems (184 A1 and MCF 10A) for the investigation of the mechanism of low-linear energy transfer (LET) RIBE. The combination of these 3D cell systems and our newly developed, high-speed confocal microscope will enable the real-time 3D visualization of cell signaling.
We are developing the tools to monitor signals in living cells in real time and characterize the response pattern in these cells. Using these methods, we will examine the signaling initiated in intact structures and monolayers by various doses of low-LET gamma radiation (0.1-10 cGy) and through the localized delivery of radiomimetic agents. The contribution made by gap junction and diffusion-mediated signaling pathways will be investigated. The long-term consequences of the low-LET RIBE in both 2D and 3D culture will be examined by mixing irradiated and non-irradiated cells. The effect of dose and the proportion of irradiated cells on cell survival and growth, cell differentiation, activation of signaling pathways, and the pattern of gene induction will be determined. This study of bystander-induced signaling in 3D systems will give new insight for evaluating the importance of RIBE for low-dose risk assessment.