The angiogenesis marker ED-B plus fibronectin isoform in intracranial meningiomas

Fibronectins (FNs), adhesive glycoproteins mainly expressed in the extracellular matrix, are polymorphic molecules whose various isoforms are dependent on alternative splicing patterns. The isoform containing the ED-B sequence and occurring in foetal and neoplastic tissues (oncofoetal or B+FN) has been previously recognized as a marker for angiogenesis. The distribution of this isoform was analyzed in a consecutive series of 134 surgically obtained intracranial meningiomas, using specific monoclonal antibodies. Oncofoetal FN was found to be widely distributed in the vessels of anaplastic meningiomas, with its expression being restricted in the vasculature of the typical subtypes, and absent in the neighbouring cerebral tissue. The ubiquitous vascular expression of B+FN in meningiomatous malignancies might provide a potential target for the in vivo delivery of angiosuppressive agents.