Figure 2

Caspase-3 activation increased and radiation-induced γH2AX fluorescence decreased in a time-dependent manner. (A) NP18 cell-plugs were irradiated with 45 Gy and incubated to allow for 0, 1, 2 or 4 h of repair. Illustrative DAPI stained nuclei (blue), fluorescence from caspase-activated cells (red), and γH2AX fluorescence (green) pictures are shown at 0 and 4 hours incubation times. Regions of interest (ROI) are depicted (original magnification, ×1000). (B) NP18 cell-plugs were irradiated (white bars) or not (black bars) and anoikis (% of cells showing activated caspase in 100 cells counted per time point) were determined. (C) In the same cells as in panel B, γH2X fluorescence (within DAPI-ROI in 150 nuclei counted per time point) was measured in caspase-negative cells. Data were obtained from 2 independent experiments. P-values were calculated using the Mann-Whitney test.