Collagen-induced rapid morphogenesis of human mammary epithelial cells: The role of the α 2 β 1 integrin

Abstract

The cell line MTSVl-7, originally derived by immortalizing mammary epithelial cells cultured from human milk was able to form three-dimensional structures in collagen gel. We have now found that these cells, cultured as a monolayer, are able to undergo rapid morphogenesis forming ridges and balls around collagen fibres, when soluble collagen type I is added to the medium. Monoclonal antibodies to the α2(PlE6) and β1(mAB13) subunits of VLA-2, but not to the α3-subunit (P1B5) of VLA-3, could block this collagen-induced rapid morphogenesis (CIRM). The effect of the antibodies on cell attachment, spreading, and migration on collagen gels was analyzed to identify α2β1 dependent steps which might be involved in CIRM. The results suggest that while other proteins, besides α2α1, are also involved in cell attachment and migration, cell spreading was specifically blocked by antibodies to the VLA-2, but not to the VLA-3 integrin. The results demonstrate that the α2α1 integrin plays a crucial role in the collagen-induced morphogenesis of human mammary epithelial cells and implicate the process of VLA-2-dependent cell spreading as an important step in this morphogenesis.