Interactions of glioma cells and extracellular matrix.

The communication between tumor cells and extracellular matrix (ECM) is responsible for clinically important features of malignant gliomas, such as cerebral invasion and leptomeningeal spread. The synthesis of ECM components, ECM-degrading activities and ECM receptors as well as the interaction between ECM components and their receptors represents the molecular basis for these processes. Recent studies have shown that proteases and integrins, the major group of ECM receptors, may be over-expressed by astrocytic tumor cells. Furthermore, integrins and the hyaluronate receptor CD44 have been found to be involved in adhesion and basement membrane invasion of glioma cells. Critical issues which are poorly understood so far include the ECM composition of the normal human brain and of brain tumors, the function of individual ECM components and receptors in a neuro-oncological context, and the molecular processes mediating the diffuse invasion of glioma cells into the brain.