Roles of Matrix Metalloproteinase-2 and -9 on the H-ras-Induced Invasive Phenotype in Human Breast Epithelial Cells and Human Fibrosarcoma Cells

One of the most frequent dejects in human cancer is the uncontrolled activation of the ms-signaling pathways. Significant evidence has accumulated to directly implicate members of the matrix metalloproteinases (MMPs) in tumor invasion and metastasis formation. We have previously shown that MMP-9 expression was significantly enhanced in the ras-tranfected HT1080 human fibrosarcoma cells at the mRNA level. In the present study, we investigated the roles of MMP-2 and -9 on the H-ras-induced invasive phenotypes of MCF 10A human breast epithelial cells and HT 1080 human fibrosarcoma cells. We show that H-ras is able to induce or enhance a signaling pathway leading to the enhancement of an invasive phenotype in both MCF10A and HT1080 cells as determined by matrigel invasion assay. We then examined the effect of H-ras activation on the expression of MMP-2 and -9 by measuring enzymatic activities and mRNA levels. Our data clearly demonstrated that H-ras prominently induces expression of MMP-2 in MCF10A cells, while it efficiently up regulates MMP-9 in HT1080 cells. Taken together, these findings suggest that the correlation between ras-mediated invasiveness and enhanced expression of MMPs may be cell type-specific: MMP-9 is closely associated with the invasive phenotype induced by ras activation in fibrosarcoma cells, whereas MMP-2 is more likely associated with it in epithelial cells.