Abstract
Radiation has been reported to induce low-dose specific effects on cells. Adaptive response and low-dose hypersensitivity of some cells suggest that low-dose irradiation induces cell survival relating repair processes. However the relationship between cellular effects and molecular processes remains unknown in low-dose specific effects. Here we have tried to investigate low-dose specific cell survival induction using human breast cancer cell line (MCF7). 5 hour after the culture of MCF7 cells, the cells were irradiated at 0.1, 0.25, 0.5 and 1Gy. The cell survival rates of the irradiated cells decreased dose-dependently at 0.1, 0.5 and 1Gy. However, at 0.25Gy the cell survival rate increased significantly. Interestingly, irradiation 24 hour after the culture had no significant increase in cell survival at 0.25Gy. To study the molecular processes, phosphoproteome analysis was performed using the cells irradiated at 0.25Gy. Protein kinase C (PKC) is known to be involved in cell survival signaling cascade. Using a phospho-PKC substrate antibody, changes in PKC signaling cascade was studied as a phosphoproteome analysis in cell survival induction. Some of the substrates were phosphorylated after irradiation at 0.25Gy. Mechanisms of low–dose specific cell survival induction will be discussed with the data showing culture condition dependency.
