Figure 3.

A combination of photons and hydrogen peroxide induces DNA damage in BTC cells. (A) Western blots showing the level of histone H2AX Ser139 phosphorylation (γ-H2AX), ataxia-telangiectasia mutated (ATM) Ser1981 phosphorylation, and total ATM in the BTC cell lines receiving 5 Gy photons or 1 μM H₂O₂ for 4 h; α-tubulin was the loading control. (B) Top: the BTC cells receiving 5 Gy photons or 1 μM H₂O₂ for 4 h were fixed and stained with H2AX Ser139 phosphorylation (γ-H2AX) and nuclei. Scale bar = 25 µm. Bottom: the relative fluorescent intensity of γ-H2AX was measured for each field (n = 3) and expressed as the fold change relative to the level of RBE cells with the treatment of 5 Gy photons or 1 μM H₂O₂ for 4 h. The values (means ± SD) are from three independent experiments. * p < 0.05 by Student’s t-test.