Effect of calcium-binding protein S100A8 in macrophage cell line RAW264.7 of mouse injured by irradiation

In order to establish the stable clones of RAW264.7 cells with S100A8 gene overexpression, and directly investigate the role of S100A8 in γ-rays induced hematoiesis/immune system injury, RT-PCR method and immuno-fluorescence staining analysis were performed to measure the expression of S100A8 mRNA and protein. The cell cycle was detected by flow cytometry at 6 h after irradiation with 10 Gy γ-rays. The level of reactive oxygen intermediates (ROIs) was detected by flow cytometry at 6h after H2O2 treatment. The cell cycle analysis showed that the percentages of RAW264.7/S100A8 cells had an increase in G0/G1 phase and a decrease in S phase, and G2/M arrest didn't occur in experimental group while the level of ROIs was lower than that of the negative control cells. These results indicate that radiation resistant of RAW264.7/S100A8 cells may be related to the antioxidant role of over-expressed S100A8 in comparison to RAW264.7/pcDNA3.1+ cells. (authors)