G2/M checkpoint activation in MCTS treated with etoposide. (A): Capan-2 spheroids treated or not with 5 μM etoposide for 48 h. Visualization of Fucci-red and Fucci-green expressing cells. Nuclei are stained with DAPI (blue). Scale bar: 50 μm. (B) Capan-2 spheroids treated or not with 1 μM or 5 μM etoposide for 24 or 48 h. Quantification of the percentage of Fucci-red and Fucci-green expressing cells as function of the distance to the spheroid surface. For each condition, data correspond to the mean+/−SEM of percentage of positive cells on 10-30 sections from 2 or 3 independent experiments with 5 to 10 different spheroids each.