Movie 1.

The Sustained Plasma Membrane Macropinosome Ruffles Characteristic of Cancer Cells with Activating Wnt Pathway Mutation Stop within Minutes of Addition of Ouabain; Related to Fig. 3. SW480 cells have sustained macropinocytosis [5] that involves the uptake of significant extracellular fluid and solutes by forming large vesicles (>0.2 μm) called macropinosomes (arrow) that were reduced rapidly after treatment with Ouabain (200 nM). Since macropinocytosis is required for Wnt signaling [50]–[54], blocking macropinocytosis explains the potent inhibitory effects of Ouabain on canonical Wnt signaling.