MMP-2 is a Determinant for Cell Migration and Invasion

Cellular migration and invasion are central to biological processes. In addition to intricate interactions between cell membrane receptors and extracellular matrix (ECM) molecules, matrix metalloproteinases (MMPs) may modify the behavior of cells, likely via proteolytic modification of the substrates. Objectives: To determine the potential contribution of MMP-2 to cell migration and invasion. Methods: We generated a series of recombinant (r) proteins from MMP-2 and fibronectin (FN) that contained FN type II modules with different homology to the type II modules of the MMP-2 collagen binding domain (CBD). From engineered expression constructs containing the coding sequences for the different recombinant domains, proteins were expressed in E. coli, affinity-purified by Zn2+- and gelatin-affinity chromatography, and verified by SDS-Page, Western blotting, and mass spectrometry. An assay was devised and optimized to measure cell migration on collagen-coated slides. In cell invasion assays, the numbers of cells penetrating 8 mm pores in collagen-coated polycarbonate filters were counted. Results: The cell migration assay efficiently quantified cell migration over 2-3 days. Although HT1080 fibrosarcoma cells migrated well in 0.1% serum, human gingival fibroblasts (hGF) required 0.25% serum. Whereas a broad MMP inhibitor reduced migration of HT1080 cells by ~50%, soluble recombinant type II modules did not significantly alter the migration of hGF or HT1080 on collagen. Yet, rCBD induced changes in cell morphology pointing a modified attachment mechanisms. Inhibition of MMPs also strongly reduced cell invasion of HT1080 cells (>60%). That MMP-2 contributes to invasive cell behavior was suggested by a ~ 45% reduction in cell invasion in the presence of 2.2 mM rCBD, an effect not observed for acetylated, non-functional rCBD. Conclusions: These data clearly implicate MMP-2 is a determinant in controlling the behavior of hGF and HT1080 on collagen surfaces. (Supported by NIDCR grants DE14236 and 12818).