Reorganization of the actin cytoskeleton underlies cell migration in a wide variety of physiological and
pathological processes, such as embryonic development, wound healing, and
tumor cell invasion. It has been shown that actin assembly and disassembly are precisely regulated by intracellular signaling cascades that respond to changes in the cell microenvironment,
ligand binding to surface receptors, or oncogenic transformation of the cell. Actin-nucleating and actin-depolymerizing (ANFs/ADFs) and nucleation-promoting factors (NPFs) regulate cytoskeletal dynamics at the leading edge of migrating cells, thereby modulating cell shape; these
proteins facilitate cellular movement and mediate degradation of the surrounding extracellular matrix by secretion of lytic
proteases, thus eliminating barriers for
tumor cell invasion. Accordingly, expression and activity of these
actin-binding proteins have been linked to enhanced
metastasis and poor prognosis in a variety of
malignancies. In this review, we will summarize what is known about expression patterns and the functional role of actin regulators in gastrointestinal
tumors and evaluate first pharmacological approaches to prevent invasion and metastatic dissemination of malignant cells.