p53 inhibits the PDGF-induced formation of circular dorsal ruffles in immortalized RASM cells.
(A) Expression of p53 and MDM2 in immortalized RASM cells expressing the empty retroviral vector, wtp53, shp53-1 or shp53-2 were analysed by Western blots using GAPDH as a loading control. (B) The effects of p53 expression or activity on CDR formation. RASM cells were serum starved overnight and treated with 20 ng/ml PDGF for 20 min. p53 activity was either up-regulated by 500 ng/ml doxorubicin or inhibited by 20 µM PFA for 30 min before and during PDGF treatment. CDRs were fluorescence stained for cortactin and F-Actin (phalloidin). The percentage of cells producing at least one CDR were counted, and normalized to that of the control cells expressing empty vectors or control shRNA. Error bars represent standard deviation from at least 3 separate experiments, * represents p<0.05 with respect to the control cells.