STROMAL ANGIOGENESIS IN HUMAN GLIOMA - A ROLE OF PLATELET-DERIVED ENDOTHELIAL-CELL GROWTH-FACTOR

BACKGROUND Although several tumor angiogenic factors have been identif ied previously and characterized, it is not yet fully clear how tumor angiogenic factors induce endothelial cell transformation and prolifer ation. platelet-derived endothelial cell growth factor (PD-ECGF) has b een recently discovered to be an endothelial cell growth factor initia lly purified from human platelets. However,there has been no previous report describing the significance of PD-ECGF in the growth of brain t umors by angiogenic stimulation. We report the immunohistochemical loc alization of PD-ECGF in human gliomas and meningiomas, and discuss whe ther PD-ECGF could play a role in the modulation of stromal angiogenes is in human glioblastoma multiforme. METHODS Twenty-eight cases of gli oma (11 glioblastomas and 17 astrocytomas) derived from the neuroectod erm in embryogenesis and 12 meningiomas from the mesoderm were investi gated by both immunohistochemical localization of the PD-ECGF and a se miquantitative assay to determine the degree of stromal angiogenesis.R ESULTS Numerous PD-ECGF positive cells were observed within and around the blood vessels of glioblastoma multiforme, especially on the borde rs of tumor tissue. The PD-ECGF positive cells were negative for anti- von Willebrand factor (VWF) and antiglial fibrillary acidic protein (G FAP) antibodies and were positive for antimacrophage (HAM-56). The exp ression of PD-ECGF by macrophages closely correlated with the degree o f stromal vascularity in glioblastoma multiforme; no such correlation was found in either astrocytoma or meningioma. Proliferating cell nucl ear antigen (PCNA) was found to be positive in some endothelial cells of stromal vessels in glioblastoma multiforme. These findings suggest that PD-ECGF expressed by macrophages plays an important role in the g rowth of glioblastoma multiforme with stromal angiogenesis. (C) 1998 b y Elsevier Science Inc.