Moving Aggressively: S100A4 and Tumor Invasion

Tumor cell invasion and metastasis are complex multi-step cellular ­processes that involve the ability of malignant cells to escape the primary tumor, migrate to distant sites within the body and establish secondary tumors. S100A4, a member of the S100 family of Ca2+-binding proteins, is a prognostic marker in a number of human cancers and has a direct role in promoting metastatic disease. S100A4’s metastasis promoting properties are attributed to diverse biological ­functions including the regulation of apoptosis, cell motility, invasion and angiogenesis. In this chapter we discuss the contribution of tumor and stromal-derived S100A4 in supporting metastatic dissemination and examine the biochemical properties of S100A4 and the S100A4/target protein interactions that may contribute to its function as a metastasis factor.