Morphological change and growth of EMT-induced MKN-1 cells in 3D collagen gel.

(A) MKN-1 cells were incubated in 3D collagen with or without indicated cytokines on 3-well chamber slides for 7 days. Culture medium was changed every 3rd day. Scale bar, 50 µm. (B) After 5-day incubation, the numbers of total cell clumps and ones with protrusions were counted in a center field under a microscope, and the percentage of protrusion-positive cell clumps was calculated. Each bar indicates the mean ± SD of the relative numbers of protrusion-positive cell clumps in triplicate wells. (C) After 7-day incubation, the cells in collagen gel were stained with Dojindo cell counting kit 8 for 4 h, and the absorbance at 485 nm of each culture medium was measured. Each bar indicates the mean ± SD of the absorbance values in triplicate wells. Other experimental conditions are described in Materials and Methods.