Figure 4.

Phenotypic changes of AGS-MUC4 cells compared with AGS-vector cells. (A) Cell motility assay: MUC4 expression correlates with the cell motility. Cells (1 × 10⁶) were plated in the top chamber of noncoated polyethylene teraphthalate membranes and incubated for 20 h. Cells that transversed the membranes were stained with a Diff-Quick cell staining kit. The number of cells transversing the membrane was determined by averaging 10 random fields of view at × 100 and expressed as the average number of cells/field of view and is the average of two independent experiments. Mean±s.e.; n=20; ^*P<0.005. Cell motility was significantly (P<0.005) increased in MUC4-transfected AGS cells. (B) Aggregation assay: drops of medium (20 μl each) containing 500 cells/drop were pipetted onto the inner surface of the lid of a Petri dish. After overnight incubation at 37°C, the lid of the Petri dish was inverted and photographed using a Nikon TS100 inverted tissue culture microscope at × 40 magnification. An increased cellular aggregation observed in AGS-MUC4 cells.