α6β4 and α6β1 Integrins in Astrocytomas and Other CNS Tumors

Laminin may alter the biological behavior of gliomas. Therefore, we investigated the expression of two laminin receptors, α6β1 and α6β4 integrins in normal brain, astrogliotic brain, and astrocytomas as compared to other central nervous system (CNS) tumors. In most CNS tumors, the expression of these integrins was unchanged in neoplastic as compared to normal counterpart cells. In contrast, increased numbers of reactive and neoplastic astrocytes expressed β4 integrin as compared to normal astrocytes, whereas α6 and β1 integrin expression did not change. Conversely, lower numbers of astrocytoma blood vessels expressed β4, whereas all blood vessels in normal brain expressed β4. These data suggest that the profile of laminin receptors changes in neoplastic astrocytes and in astrocytoma blood vessels; this change may play an important role in astrocytoma pathogenesis.