Modulation of matrix metalloprotease-2 and invasion in human glioma cells by α3β1 integrin

We have investigated the effect of integrin antibodies to a well-characterized α5β1 (fibronectin receptor) and to a multi-specific α3β1 (laminin, collagen, and fibronectin receptor), on the expression of matrix metalloproteases and the invasion ability of two human glioblastoma cell lines, SNB19 and U251. Cell adhesion assays indicated that both cell lines adhere to fibronectin, type IV collagen and laminin. Adhesion of cells to fibronectin was inhibited by a RGD peptide. Cells treated with anti-α3β1 or anti-α5β1 antibodies expressed increased levels of MMP-2. An in vitro matrigel assay also showed that the α3β1 antibody-treated cells had greater invasive ability than the controls. Immunofluorescence data showed that glioma cells treated with either anti-α3β1 or anti-α5β1 antibodies expressed diminished α3β1 and α5β1 integrins relative to the controls. The data show that treatment of cells with α3β1 antibody diminishes the integrin expression on the cell surface and increases the MMP-2 activity and invasiveness.