Fig. 4

AUY922 abrogates ATR-CHK1 signaling allowing increased chromosomal fragmentation in response to CCRT. a Scheduling showing 0 h time point post 16 h AUY922 addition but pre-RT, cisplatin or combined CCRT addition and subsequent time point analysis post as used in panels b-f. b AUY922 disruption of ATR-CHK1 signaling in response to CCRT alongside depletion of total RAD51. c Mitotic accumulation as measured by FACS analysis of phospho-histone H3 positive cells. d Co-staining for phospho-histone H3 and γH2Ax was analyzed by FACS. Population plotted is the percentage of the total cell number positive for both high γH2Ax levels and the mitotic marker phospho-histone H3. e γH2Ax staining in mitotic cells was confirmed in HNSCC cell lines by confocal microscopy, DAPI as nuclear stain. Nuclei with mitotic morphology indicated by arrows. f Micronuclei quantification of DAPI stained confocal images at 24 h in response to CCRT and AUY922. Values are mean ± SEM of at least three independent experiments. Statistical analysis by 2-tailed t-test; *p < 0.05, **p < 0.01, ***p < 0.001