Quantitative proteomic analysis of single or fractionated radiation-induced proteins in human breast cancer MDA-MB-231 cells

Background Radiotherapy is widely used to treat cancer alone or in combination with surgery, chemotherapy, and immunotherapy. However, damage to normal tissues and radioresistance of tumor cells are major obstacles to successful radiotherapy. Furthermore, the immune network around tumors appears to be connected to tumor progression and recurrence. Methods We investigated the cytosolic proteins produced by irradiated tumor cells by using a quantitative proteomic approach based on stable isotope labeling by amino acids in cell culture. MDA-MB-231 breast cancer cells were treated with a single or fractionated 10 Gray dose of 137 Cs γ-radiation, which was selected based on cell viability. Results Radiation-induced proteins were differentially expressed based on the fractionated times of radiation and were involved in multiple biological functions, including energy metabolism and cytoskeleton organization. We identified 46 proteins increased by at least 1.3-fold, and high ranks were determined for cathepsin D, gelsolin, arginino-succinate synthase 1, peroxiredoxin 5, and C-type mannose receptor 2. Conclusion These results suggest that a number of tumor-derived factors upregulated by γ-radiation are promising targets for modulation of the immune response during radiation treatment.