Neuro-oncology
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Vascular endothelial growth factor (VEGF) is one of the key regulators of tumor neoangiogenesis. It acts through two types of high-affinity tyrosine kinase receptors (VEGF receptor-1 [VEGFR-1]/fms-related tyrosine kinase 1 [Flt-1] and VEGFR-2/kinase domain receptor [KDR]) expressed on endothelial cells. VEGFRs have also been detected on cancer cells, suggesting a possible autocrine effect of VEGF on their growth. ⋯ In DAOY cells, VEGF(165) induced phosphorylation of VEGFR-2/KDR and of downstream proteins in the signal transduction pathway. These data suggest a possible autocrine role for VEGF in medulloblastoma growth. Targeting VEGF signaling may represent a new therapeutic option in the treatment of medulloblastoma.
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Neural stem cells with astrocyte-like characteristics exist in the human brain subventricular zone (SVZ), and these cells may give rise to glioblastoma multiforme (GBM). We therefore analyzed MRI features of GBMs in specific relation to the SVZ. We reviewed the preoperative and serial postoperative MR images of 53 patients with newly diagnosed GBM. ⋯ Group I GBMs may be most related to SVZ stem cells; these tumors were in intimate contact with the SVZ, were most likely to be multifocal at diagnosis, and recurred at great distances to the initial lesion(s). In contrast, group IV GBMs were always solitary lesions; these may arise from non-SVZ, white matter glial progenitors. Our MRI-based classification of GBMs may further our understanding of GBM histogenesis and help predict tumor recurrence pattern.