Characterization of endothelial cells isolated by human meningiomas

Meningiomas are common neoplasms of central nervous system characterized by a prominent angiogenesis in some histological subtypes and in some phase of their progression. Angiogenesis is a required event for the progression of solid tumor. However there are increasing evidences that the biological features of endothelial cells in the tumor other than the microvessel number dictate the behavior of cancer disease. In the present study we have tested the hypothesis that in vitro endothelial cells originated by human meningiomas have a different phenotype from that of normal capillary endothelial.

To isolate endothelial cells we have used a new technical approach principally based on collagenase digestion of the tissues followed by capture of endothelial cells obtained through molecules recognizing specific endothelial markers conjugated to magnetic beads.

By using beads conjugated with a monoclonal antibody anti CD-36 we have separated with high efficiency and purity meningioma endothelial cells and established three cell cultures. These cells uptake acetylated LDL and express CD-31, CD-36, nitric oxide synthase type III, von Willebrand factor, which are specific markers of endothelial cells. Their mitogenic and motogenic potential in resting conditions or after stimulation with vascular endothelial growth factor-A is superimposable to that of normal capillary endothelial cells. However meningioma endothelial cells produce higher amount of interleukin-6 and of monocyte chemotactic peptide-1 than control cells.

The establishment of a new and suitable technique to isolate endothelial cells from human cancers can be useful to learn more on angiogenic mechanisms in tumor progression. Furthermore, the data shown underline the possible pathogenic role in meningioma progression of infiltrating macrophages triggered by monocyte chemotactic peptide-1 released by tumor endothelial cells.