The research in my laboratory focuses on a specific family of cell surface receptors, the syndecans, and their role in initiating intracellular signal transduction. The syndecans are a four member family of cell surface heparan sulfate proteoglycans that mediate adhesion to the extracellular matrix. The heparan sulfate chains also bind to growth factors, such as the fibroblast growth factors, and regulate their signaling. The consequences of these activities, and their defects, are important to our understanding of cancer.
Metastatic cells show defects in cell adhesion that correlate with altered syndecan expression.
A current question in syndecan biology is how these receptors form signaling complexes at the cell surface. Numerous questions remain to be answered regarding the regulatory role of heparan sulfate in this signaling complex. As the sulfation sequence in heparan sulfates can be quite variable, their ability to bind specific FGFs and FGF receptors is equally variable. This, in turn, determines whether or not a given proteoglycan type will participate in the formation of a signaling complex. Ongoing studies that localize specific heparan sulfates in vivo show that they differ in their ability to form signaling complexes with specific FGFs.