Intense focal expression of vascular endothelial growth-factor messenger-RNA in human intracranial neoplasms - association with regions of necrosis.

To examine the potential involvement of vascular endothelial growth factor (VEGF) in vascular changes which occur in human intracranial neoplasms, we examined a series of tumor specimens for expression of VEGF mRNA by in situ hybridization. VEGF was expressed at high levels by tumor cells in discrete regions in several of the tumors examined. The highest levels were detected in glioblastomas. The presence and location of foci of intense VEGF mRNA expression were, paradoxically well correlated with the presence of necrobiosis within the tumor mass. A less consistent association was observed between VEGF expression and either the degree of vascularization or endothelial cell proliferation. Since VEGF has been shown to induce tissue factor expression, VEGF itself may be involved in the pathogenesis of necrosis. Our findings provide evidence that VEGF mRNA is highly expressed in specific intracranial malignancies and suggest that VEGF plays a complex and multifunctional role in vascular biology.