VEGF AND TPA COEXPRESSED IN MALIGNANT GLIOMA

Neovascularisation and migration of tumour cells are two features of h ighly malignant glioma. Vascular endothelial growth factor (VEGF) and tissue plasminogen activator (tPA) seem to be of importance in the pro cess of malignancy. In the present study a topographical co-expression of tPA mRNA and VEGF mRNA (VEGF(121) and VEGF(165) isoforms) was demo nstrated in the tumour edge of a rat malignant glioma, using in situ h ybridisation. No signs of co-expression was seen in the normal brain t issue. In the normal brain the forms of VEGF mainly expressed were VEG F(121), VEGF(165), and VEGF(189). Further studies are required to show whether VEGF and tPA are produced by the same tumour cells and to elu cidate the role of this co-expression.