Fig. 5

Clonogenic survival following the treatment of SK-N-BE(2c) and UVW/NAT cells with rucaparib or olaparib and X-radiation or ¹³¹I-MIBG as single agent modalities or in combination. SK-N-BE(2c) (a, c) and UVW/NAT cells (b, d) were treated with 10 μM rucaparib (black bars), 10 μM olaparib (white bars), 3 Gy X-radiation (a, b) or 1 MBq/ml ¹³¹I-MIBG (c, d), as single agents or in combination. The outcome of the latter treatment is designated as ‘combination observed’ in the figure. Cells were incubated for 24 h and survival was assessed by clonogenic assay. The expected surviving fraction, if the two treatments had an additive effect with respect to clonogenic cell kill, was calculated as the product of the surviving fractions resulting from single agent treatments. This is designated as ‘combination expected’ in the figure. Data are means ± SEM, n = 4; **p < 0.01, *** p < 0.001 compared to 3 Gy X-irradiation (a, b) or 1 MBq/ml ¹³¹I-MIBG treatment (c, d)