Effect of ADC on CRC cell line proliferation. (A) The indicated cell lines (Caco-2 and HCT-116) were seeded in flat-bottomed plates without (CTR, no antibody) or with 2 µg/mL of the indicated antibodies. Cell proliferation was assessed as the percentage of confluency by taking images of culture wells at the indicated time points (0, 24, 48, 72, 96, 120 h). Each point corresponds to six replicates for each experimental condition. The percentage of confluency was calculated by CellStudio 6.2 software, associated with the CellCyte XTM plate scanner. The results are expressed as mean ± SD of confluency. (B) left panel: the spheroid diameter was measured in 50 spheroids obtained with AggreWell-400 plates after 5 days of culture without (CTR) or with 2 µg/mL of the indicated antibodies. (B) right panel: the ATP content of spheroids cultured as in left panel. Results are shown as ATP content expressed in arbitrary units.