RESUMO
BACKGROUND: We have previously shown that the vimentin-positive subset of human breast cancer cell lines, which are more invasive in vitro and in vivo, can activate MMP-2 when cultured on vitrogen gels whereas the poorly invasive, poorly metastatic vimentin-negative subset cannot (J. Cell Physiol. 150: 534, 1992). METHODS: In this study, we compared the interaction of human breast cancer cell lines from each group with respect to the interaction with vitrogen. RESULTS: The cell lines capable of responding to vitrogen for MMP-2 activations showed an enhanced ability to attach to vitrogen-coated culture wells. MCF-7 (non-MMP-2 activating) and MDA-MB-231 (MMP-2 activating) cells were selected for more detailed analysis. MDA-MB-231 cells showed a greater affinity for the 3-dimensional vitrogen than MCF-7 cells. Attachment of both lines to thin coatings of vitrogen was shown to require divalent cations and to be mediated by beta1 integrins. The alpha5 subunit, however, was shown to be involved in fibronectin attachment, but not vitrogen attachment. The GRGDSP peptide dramatically inhibited fibronectin attachment of both cell lines, but did not effect the vitrogen attachment of either. In contrast, the KGDEA recognition sequence for alpha2 integrin inhibited the attachment of MDA-MB-231 cells to vitrogen, but not to fibronectin or laminin. CONCLUSIONS: These results show that the subset of human breast cancer cell lines which respond to the vitrogen gel with MMP-2 activation may interact more easily with the vitrogen, apparently through integrin-mediated recognition. Preliminary analysis reveals that the alpha2beta1 integrin, previously implicated in vitrogen interaction may mediate this response.