Angiogenic profile of childhood primitive neuroectodermal brain tumours/medulloblastomas

Primitive neuroectodermal brain tumours (PNET) including medulloblastomas ( PNET/MB) are the most common malignant brain tumours of childhood. Similar to many other brain tumours, PNET/MB often show marked neovascularisation. To determine which angiogenic factors contribute to PNET/MB angiogenesis, w e examined the expression of eight angiogenic factors (vascular endothelial growth factors ( VEGF, VEGF-B. VEGF-C), basic fibroblast growth factor (bF GF), angiopoetins (Ang-1, Ang-2), transforming growth factor (TGF-alpha). a nd platelet-derived endothelial growth factor (PDGF-A)) by semi-quantitativ e reverse transcriptase polymerase chain reaction (RT-PCR) in six PNET cell lines and 28 primary PNET/MB. Expression levels of angiogenic factors were compared with microvessel density. TrkC mRNA expression. clinical variable s and survival outcomes. Our results indicate that all PNET/MB tested produ ce a wide range of angiogenic factors that are, individually or together, l ikely to play a direct role in PNET/MB tumour growth. This suggests that an ti-angiogenesis approaches targeting VEGF alone may be insufficient in PNET /MB. (C) 2001 Elsevier Science Ltd. All rights reserved.