Biological studies of fascin function in cancer cell invasion and cancer progression

The process of metastasis is initiated through the acquisition of inherent and autonomous motile and invasive properties by tumor cells. These phenomena are initiated through a balance between forward cancer cell membrane protrusion and tail retraction, and occur via cell cytoskeleton remodeling, actin reorganization, and coordinated focal adhesion assembly and disassembly events. Among the vast network of cytoskeletal proteins, the actin-bundling protein fascin plays a major function in cell cytoskeleton remodeling. It is a 55-kDa protein involved in the formation of filopodia and cell migration, and found to be upregulated in many cancers. We report herein key functions for fascin in the regulation of prostate and breast cancer progression. Fascin expression is upregulated in localized and hormone refractory prostate cancer, responsible for a more aggressive clinical course. In addition, functional dissection of fascin reveals a novel function in the regulation of focal adhesion turnover dynamics, by modulating the phosphorylation state of central focal adhesion proteins through a potential collaboration with the protein tyrosine phosphatase, PEST. Together, our data support the importance of fascin in cancer cell invasion and as a significant prognostic marker and a potential therapeutic target for aggressive cancers