Fig. 4

Small molecule inhibition of p38, but not PI3K or ERK, blocks EGF stimulated lysosome trafficking. a DU145 cells were stimulated with 100 ng/mL EGF over time. Total cell lysates were harvested and western blot analysis was performed. b Cells were treated with 10 μM of the MAPK inhibitor, U0126, the PI3K inhibitor, LY294002, or the p38 inhibitor SB203580 for 2 h prior to 16 h 100 ng/mL EGF treatment. Cells were fixed in 4% PFA and stained for LAMP-1 (red), phalloidin (green), and DAPI (blue). Scale bar represents 30 μm, N = 3. c Quantification of lysosome distribution of 25 cells per treatment. Error bars represent standard error of the mean. * = p < 0.05 vs. respective control treatments