Figure 5

YM155 suppresses radiation-induced DSB repair in ESCC cells. A. YM155 led to significant increase in γ-H2AX staining. B. YM155 inhibited the formation of radiation-induced Rad51 foci. Eca109 cells were treated with 0.1% DMSO or 10 nM YM155 and then exposed to 4 Gy of X ray. After incubation for the indicated times, the cells were fixed for immunofluorescence detection of γ-H2AX (green) and Rad51 (red) foci. Representative images of nuclei (blue) and foci were shown (left lane), scale bar, 10 μm. Data were expressed as the percentage of cells staining positive for foci and plotted as the mean SEM of 3 independent experiments (right lane). Nuclei containing ≥10 immunoreactive foci were scored as positive for γ-H2AX, and ≥5 foci as positive for RAD51. At least 100 nuclei were counted for each experiment. * and #, P < 0.05; **, P < 0.01.