The role of integrin receptors in aspects of glioma invasion in vitro

Integrins are heterodimers consisting of non-covalently associated alpha and beta subunits. They mediate adherence of normal and tumour cells to the extracellular matrix, a property which is essential for migration of neoplastic astrocytes as they invade into the normal brain parenchyma. Flow cytometry and immunocytochemical analysis of cultured cells derived from 10 gliomas (1 pilocytic astrocytoma, 1 astrocytoma, 1 oligoastrocytoma, 1 anaplastic oligoastrocytoma, 4 anaplastic astrocytomas and 2 glioblastoma multiforme) revealed that the beta(1) integrin subunit was generally expressed more strongly than alpha(4) or alpha(v) integrin subunits. Subsequent studies with function-blocking antibodies against the beta(1) subunit inhibited adhesion, motility and invasion of the gliomas in vitro, to varying degrees, on all extracellular matrix substrates investigated (laminin, collagen type IV, fibronectin and vitronectin), the inhibition by beta(1) subunit was greatest on collagen type IV. These studies therefore substantiate the case for a role of the beta(1) integrin subunit in neoplastic glial cell invasion of the brain. (C) 1999 ISDN. Published by Elsevier Science Ltd. All rights reserved.