Evaluation of in Vitro Reconstituted Basement Membrane Assay to Assess the Invasiveness of Tumor Cells

The crossing of tumor cells through basement membranes represents a critical step in the metastatic process. We have used a reconstituted basement membrane (matrigel) coated on filter in a Boyden chamber to assess the invasive potential of tumor and normal cells. No correlation was found between chemoinvasion in vitro and the metastatic potential in vivo. Normal human fibroblasts and murine 3T3 fibroblasts penetrated filters coated with matrigel. On the other hand, the tumoral cells (MCF7, MCF7 gpt, MCF7 ras, BeWo, JAR, NUC-1 cells) were unable to cross the matrix. Our results suggest that in our conditions, this widely used model to assess tumoral invasion does not provide a universal assay to test the invasiveness of tumor cells. Penetration of the matrigel appears to be related to chemotactic or haptotactic responses depending upon cell types. Our data emphasize the variability of molecular events associated with basement membrane invasion.