FIGURE 4.

Ceramide synthesis may contribute to migration activity and lamellipodia formation. A, Ceramide amounts were quantitated in LNM35 cells (n = 3). The experiment was replicated, and similar results were obtained. B, Migration assays were performed with myriocin (100 nM, n = 4, mean ± SD) or fumonisin B₁ in LNM35 cells (20 µM, n = 3, mean ± SD). Myriocin and fumonisin B₁ experiments were replicated and triplicated, respectively, and similar results were obtained. C, After treatment of LNM35 cells with siCERS6‐1, migration activity was determined with C16 ceramide (1 µM) (n = 4, mean ± SD). The experiment was replicated, and similar results were obtained. D, LNM35 cells were starved and stimulated by serum for 12 hours and then subjected to immunocytochemistry using anti‐RAC1 and anti‐pPKCζ antibodies. Bar = 10 µm. E, In groups of 100 cells or more, those with RAC1‐positive lamellipodia were counted and the results plotted (percentage, mean ± SD). F, RERF‐LC‐AI cells were starved and stimulated for 12 hours and then subjected to immunocytochemistry using an anti‐RAC1 antibody. Bar = 50 µm. Representative image of triplicate experiments is shown. G, In groups of 100 cells or more, those with RAC1‐positive lamellipodia were counted and the results plotted (percentage, mean ± SD).