p53 controls colorectal cancer cell invasion by inhibiting the NF-κB-mediated activation of Fascin.

p53 mutation is known to contribute to cancer progression. Fascin is an actin-bundling protein and has been recently identified to promote cancer cell migration and invasion through its role in formation of cellular protrusions such as filopodia and invadopodia. However, the relationship between p53 and Fascin is not understood. Here, we have found a new link between them. In colorectal adenocarcinomas, p53 mutation correlated with high NF-κB, Fascin and low E-cadherin expression. Moreover, this expression profile was shown to contribute to poor overall survival in patients with colorectal cancer. Wild-type p53 could inhibit NF-κB activity that repressed the expression of Fascin and cancer cell invasiveness. In contrast, in p53-deficient primary cultured cells, NF-κB activity was enhanced and then activation of NF-κB increased the expression of Fascin. In further analysis, we showed that NF-κB was a key determinant for p53 deletion-stimulated Fascin expression. Inhibition of NF-κB/p65 expression by pharmacological compound or p65 siRNA suppressed Fascin activity in p53-deficient cells. Moreover, restoration of p53 expression decreased the activation of Fascin through suppression of the NF-κB pathway. Taken together, these data suggest that a negative-feedback loop exists, whereby p53 can suppress colorectal cancer cell invasion by inhibiting the NF-κB-mediated activation of Fascin.