Phenotypic and functional characteristics of tumour-derived microvascular endothelial cells

We recently developed a method for the isolation and purification of tumour -derived endothelium. In this study the phenotypic and functional propertie s of human tumour-derived microvascular endothelial cells (TdMEC) were exam ined. Endothelium obtained from human adrenal gland specimens (HAMEC) was u sed as a reference microvascular endothelial cell population. TdMEC formed a confluent monolayer with the typical morphological appearance of endothel ium and were positive for endothelial markers such as Ulex-1 lectin, CD31 a ntigen, von Willebrand Factor and VE-cadherin. The addition of acidic Fibro blast Growth Factor (aFGF), basic FGF (bFGF) or Vascular Endothelial Growth Factor (VEGF) substantially improved proliferation of TdMEC; and kidney ca rcinoma derived endothelial cells were more responsive to FGFs, whereas gli oblastoma derived endothelial cells greatly responded to VEGF. TdMEC expres sed high levels of the VEGF receptors, KDR/flk-1 and Flt-1, as shown by nor thern blot analysis. TdMEC expressed the adhesion molecules ICAM-1, VCAM-1 and E-selectin that could be further increased by exposing TdMEC culture to interleukin-1. All the TdMEC expressed interleukin-8 mRNA. These findings show that TdMEC in vitro maintain several of the features described for mic rovasculature. Thus, TdMEC represent a useful tool to study markers for tum or vasculature.