Adhesion receptors and cell invasion: mechanisms of integrin-guided degradation of extracellular matrix

The integrins are a large family of heterodimeric cell adhesion receptors m ediating cell-matrix and cell-cell adhesion. They seem to play a central ro le in cell migration and invasion and are therefore essential in processes such as healing of tissue injuries and the progression of human cancer. Int egrins function in cell invasion by mediating cell movement on matrix molec ules and also by regulating the expression of matrix-degrading enzymes, nam ely the matrix metalloproteinases. Here we review recent findings on the me chanisms by which integrins regulate matrix degradation. A novel, multistep model of integrin-guided collagen degradation is proposed.