TUMOR PROGRESSION - THE ROLE OF CADHERINS AND INTEGRINS

Established cadherin and integrin-containing adherens junctions mainta in the integrity of normal tissues. Signalling via adhesion-molecule s ystems is an important factor in the control of cellular growth and di fferentiation, in transformed cells, destructive changes in the adhesi on systems lead to abnormal relationships among neighbouring cells and the extracellular matrix. Adhesion molecules may prevent tumour progr ession by firmly attaching cells to each other, and by anchoring them in the extracellular matrix. In addition, cadherins and integrins may have a direct role in tumour suppression by participating in growth co ntrol. Dissemination of cancer cells, i.e. invasion and metastasis, re quires movement of cells, as well as adhesion to extracellular matrice s and to other cells. Particular integrins have been implicated in sev eral aspects of this multistep process. In this article, the possible roles of cadherins and integrins in tumour progression are summarized.