Metastasis is a complex pathophysiological event which involves proteolytic degradation of extracellular matrix components and migration of tumor cells to specific organs located at a distance from the primary tumor. Extracellular matrix turnover is controlled by specific metalloproteinases, including collagenase and stromelysin. The activity of these enzymes is regulated by proenzyme activation, by the action of a specific tissue inhibitor of metalloproteinase (TIMP), and by transcriptional modulation. In experimental animal models, stimulation of extracellular matrix formation or inhibition of matrix degrading proteases has ben shown to strongly inhibit tumor formation. Experimental evidence has demonstrated the existence of coordinately regulated signalling pathways which stimulate matrix formation and inhibit matrix degradation. In Phase I we intend to develop reporter plasmids which measure (1) attenuation in transcription of the collagenase type IV gene (encoding a protease responsible for the degradation of extracellular matrix) and (2) increased transcription of the tissue inhibitor of metalloproteinases (TIMP). Cell lines obtained by transfection of these plasmids will become incorporated into a high throughput screen for anti-metastatic compounds using a novel robotic cellular transcription screening system.
