Fascin: Invasive filopodia promoting metastasis.

Fascin is an evolutionarily conserved actin bundling protein that localizes to microspikes, filopodia and actin-based protrusions underneath the plasma membrane. fascin has received a lot of attention among cytoskeletal proteins because multiple clinical studies have implicated its expression in cancer progression and metastasis. this may be because fascin is not normally expressed in epithelial tissues and when it is upregulated as a part of a program of cancer cell epithelial to mesenchymal progression it confers special motility and invasion properties on cancer cells. in normal adult tissues, fascin expression is high in neurons and dendritic cells; both cell types have striking large filopodia and are highly motile. it is not clear how fascin promotes invasive motility in cancer cells, but many studies have implicated filopodia formation in motility and we have recently provided new evidence that fascin stabilizes actin bundles in invasive foot structures termed invadopodia in cancer cells Figure 1.1 Here we review some of the evidence implicating fascin in motility, invasion and cancer aggressiveness, and we speculate that by stabilizing actin, fascin provides cells with powerful invasive properties that may confer increased metastatic potential.