Figure 5.

p38 inhibitor restores cell growth and invasion in PPM1D-knockdown K-1 cells. (A) Cell growth was determined using a CCK-8 assay in cells with diminished PPM1D expression treated with or without SB203580. Each treatment was assayed in triplicate every 24 h for a total of 3 days. (B and C) The invasive ability of the cells was assessed using a Transwell cell invasion assay. (B) Representative images and (C) quantitative results. (D) Western blot analysis of PPM1D-silenced cells treated with or without p38 inhibitor for 24 h. The drug was used at a concentration of 100 nM. The relative quantification of protein bands as the ratio to their loading control are presented at the bottom of the western blotting. Values are expressed as the mean ± SEM of three independent experiments. P-values were determined using ANOVA test followed by Tukey's post hoc test. **P<0.01, ***P<0.001. N.S., no significance; PPM1D, protein phosphatase, Mg²⁺/Mn²⁺ dependent, 1D; CCK-8, Cell Counting Kit-8.