We speculate that chemotactic migration of leukemic cells to the pilocytic astrocytoma may be partly mediated through vascular endothelial growth factor (VEGF) and VEGF receptors.
Vascular endothelial growth factor (VEGF) mRNA levels are increased in GBM and moderate in PA. Immunohistochemical study showed that cytoplasmic AM, VEGF and HIF-1α nuclear immunoreactivity were recorded in GBM located near large necrotic areas whereas they were not expressed by PA tumour cells.
These findings suggest encouraging possibilities for targeting angiogenesis (for instance with anti-VEGF) as a therapeutic strategy in pilocytic astrocytoma.
In order to explore factors regulating such angiogenesis and cyst formation in pilocytic astrocytoma, we examined expression of VEGF and its receptors (KDR and Flt-1) using in situ hybridization.