Fig. 6
The effect of PARP-1 inhibition in combination with X-irradiation on cell cycle progression. SK-N-BE(2c) (a) and UVW/NAT (b) cells were irradiated with 3 or 10 Gy X-radiation before harvesting cells 2, 6, 12 and 24 h after irradiation. Cell cycle was analysed following by flow cytometry after staining with propidium iodide. Data are means ± SEM, n = 3; significance of differences: *p < 0.05, **p < 0.01, ***p < 0.001 compared to the unirradiated control at 0 h. SK-N-BE(2c) (c) and UVW/NAT (d) cells were treated with 10 μM rucaparib, 10 μM olaparib or 3 Gy X-radiation as single agents, or in combination. After 24 h, cells were fixed and cell cycle distribution was analysed by flow cytometry after staining with propidium iodide. Representative cell cycle profiles of UVW/NAT cells are shown in (e). Accumulation of cells in specific cell cycle phases was quantified using the Dean-Jet-Fox algorithm in FlowJo. G1, S and G2/M populations are highlighted in green, yellow and blue, respectively. Data are means ± SEM, n = 4; †p < 0.05, ††p < 0.01, †††p < 0.01 proportion of G2/M cells compared with untreated cells; *p < 0.05, **p < 0.01, ***p < 0.001 proportion of G2/M cells following combination treatment compared with each single agent treatment