Adhesion Molecules
A large family of glycoprotein molecules termed adhesion molecules
mediate the attachment of marrow precursors, leucocytes and platelets to
various components of the extracellular matrix, to endothelium, to other
surfaces and to each other. The adhesion molecules on the surface of leucocytes
are termed receptors and these interact with proteins termed ligands on the
surface of target cells, e.g. endothelium. The adhesion molecules are important
in the development and maintenance of inflammatory and immune responses, and in
platelet–vessel wall and leucocyte–vessel wall interactions.
The pattern of expression of adhesion molecules on tumour cells may
determine their mode of spread and tissue localization (e.g. the pattern of
metastasis of carcinoma cells or non‐ Hodgkin lymphoma cells into a follicular
or diffuse pattern). The adhesion molecules may also determine whether or not
cells circulate in the bloodstream or remain fixed in tissues. They may also
partly determine whether or not tumour cells are susceptible to the body’s immune defences.