The cell matrix has profound effects on the phenotypic behavior of malignant and metastatic cells. These effects range from promoting cell motility, to adhesive activities and potentially stimulating the degradation of extracellular matrices themselves. An inescapable component of metastasis is the interaction of tumor cells with cell adhesion molecules and cell matrix molecules. Because of this, we will focus on the molecular structure of cell adhesion molecule, fibronectin. Fibronectin occurs in plasma, basement membranes, and in extracellular matrices throughout the body. It is a well studied molecule that will promote the adhesion of numerous cell types and a number of laboratories have implicated its role in modulating phenotypic behavior of malignant and metastatic cells. Studies in our laboratory laid the groundwork for focusing on the ability of fibronectin to promote the cell migration of metastatic cells by haptotaxis. Because of this and our experiences working on the functional domains of fibronectin, we have proposed an intensive analysis of the domain structure of fibronectin relative to the modulation of the in vitro phenotypic behavior of highly and lowly metastatic murine cells, relative to: a) cell migration, b) cell adhesion, c) metastatic ability and d) ability to clear surfaces of adsorbed fibronectin or fibronectin peptides. Specifically, we will determine whether unique cell adhesion or cell migration peptides of fibronectin will modulate experimental metastasis, cell adhesion or migration when cells have been preincubated with these peptides. Further, we will analyze whether highly directed affinity purified polyclonal antibodies or monoclonal antibodies both new and those already known, will modify a) cell adhesion, b) cell migration, c) removal or dissolution of substratum attached fibronectin in vitro and d) invasion into the amnion. Next we will determine if there is a correlation among a) the fibronectin's ability to promote cell adhesion and migration in vitro, b) the cell's ability to remove, internalize and degrade fibronectin or fibronectin coated substrates, c) tumor invasion using the amnion assay, and d) experimental metastatic behavior. Lastly, we will attempt to generate novel monoclonal antibodies to fibronectin to block the haptotactic migration of highly metastatic cells and thereby provide a reagent to isolate using affinity chromatography of the smallest peptide which maintains the biological activity of interest.
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