Functions of the Tumor Suppressors p53 and Rb in Actin Cytoskeleton Remodeling

Figure 3

Rb-dependent regulation of the molecules involved in actin cytoskeleton remodeling. In cancer cells, Rb is inactivated either by Cdk4/6- and Cdk2-dependent hyperphosphorylation or by its mutation. Rb prevents cancer progression by suppressing both invasion and cell division via the alteration of actin cytoskeleton remodeling. Conversely, under inflammatory conditions, Rb is likely to have a promoting effect on cancer cachexia, which is associated with muscle atrophy characterized by disorganization of sarcomeres. TNFα upregulates the Cdk4/6-dependent phosphorylation of Rb, which causes disorganization of sarcomeres by inhibiting mDia1-mediated actin polymerization.