Densitometry of Erk1/2 and p-Erk1/2. Western blotting analysis of cell protein lysate was from 3D cell cultures and cell monolayers. GAPDH was used as control for loading. Densitometric analyses were performed using Alliance 4.7, Unitec (Cambridge, UK) and are presented as a ratio of Erk/GAPDH and pErk/GAPDH. The (■) dark and (grey square symbol) grey bars represent multicellular structures and cell monolayers respectively. (*) P < 0.05, compared to control multicellular structures. (#) P < 0.05, compared to control cell monolayers. (■) P < 0.05, comparison of between multicellular structures and cell monolayers. The data are presented as mean ± SEM from at least four separate experiments.