Fig. 3

The expression levels of DAB2IP modulate the radiosensitivity of ESCC cells in vitro. A Left, clonogenic survivals of DAB2IP overexpressed cells of Kyse150 cell lines were reduced compared to parental cells after a single dose radiation (0, 2, 4, 6, 8 and 10 Gy). Right, knockdown of DAB2IP increased clonogenic survival fraction of EC109. All data were from three independent experiments, and were fitted according to the linear quadratic mode. B Left panels, Kyse150-DAB2IP and control Kyse150-vector cells were treated with or without IR (3 Gy), and 48 h later, the cell apoptotic death events were monitored by Annexin V/PI staining cells. Right panels, EC109 cells, initially infected with DAB2IP-shRNA and Luc-shRNA, were treated with or without IR. After 48 h, Annexin V/PI staining was used to determine the percentage of cells undergoing apoptosis. All data described are the mean ± SD of three independent experiments. *p < 0.05. All data are reported as mean ± SD. C Forty-eight hours after the cells were treated with IR (3 Gy), the cleavages PARP and cleaved casepase-3 were detected in Kyse150-vector/Kyse150-DAB2IP (left) and EC109-shluc/EC109-shDAB2IP (right) cells by Western blot analysis. Experiments were performed three times and a representative result is shown. D The levels of DAB2IP affect IR-induced DNA damage in ESCC cells. Kyse150-vector/Kyse150-DAB2IP (upper panels) and EC109-shluc/EC109-shDAB2IP (lower panels) were irradiated with 3 Gy and immunostained for 53BP1 (red) and phospho-γH2AX (green) foci at the indicated time points after radiation. Colocalized foci (yellow) were used as a measure of DSB. Nuclei were counterstained with DAPI (blue). Columns (right) indicate quantification of average numbers of IR-induced colocalized foci per cell (0 or 36 h after IR). A total of 100 cells from three independent experiments were counted for each group. The data represent mean ± SD. (*p < 0.05, p-value was according to Student’s t test)