Assessment of angiogenesis by CD105 and nestin expression in peritumor tissue of glioblastoma

Angiogenesis in the peritumor tissue of glioblastoma (GBM) is still an open field of research. This study investigates neovascularization in the tumor surrounding areas by examining CD 105 and nestin expression along with microvessel density (MVD) with the aim of establishing their possible prognostic significance. Angiogenesis was also confirmed by investigating, in vessel walls, the presence of pericytes, which are multipotent stem cells, expressing alpha-smooth muscle actin (alpha-SMA). In our study, including 40 GBM patients, tissue samples were obtained from tumors (first area) and white matter at a distance <1 cm (second area) and between 1 and 3.5 cm (third area) from the tumor margin. CD105 and nestin were detected by immunohistochemistry in hyperplastic endothelium of GBM and peritumor tissue, and occasionally coexpressed or colocalized. Pericytes encircling hyperplastic endothelium were evident in all three areas. Univariate analysis revealed that patients with a CD105-MVD value >= 8 in the third area have a significantly shorter survival time and Cox analysis indicated an about 3.5-fold increase in death risk in the same patients. These results demonstrate that a tumor neoangiogenesis occurs in GBM peritumor tissue with intimate involvement of pericytes. CD105-MVD in the area located at a greater distance from the tumor margin carries prognostic significance.