Expression of Vascular Endothelial Growth Factor and Its Relation with Neovascularization and Apoptosis in Grading of Astrocytic Tumors

Kim, Sei Jong; Kim, Du Cheun; Lee, Min Choel

Abstract

BACKGROUND: The vascular endothelial growth factor (VEGF) is known as a potent mediator of brain tumor angio-genesis, vascular permeablity, and glioma growth. This study was designed to study the balance between growth and death signals in different grades of astrocytic tumors.
METHODS
Using immunohistochemistry, the relationship between the expression of VEGF and microvessel count and density were evaluated in 62 cases of astrocytic tumors including 33 low grade astrocytomas, 6 anaplastic astrocytomas, and 23 glioblastomas. In order to determine the apoptotic index (AI), the in situ end-labeling method was applied.
RESULTS
VEGF was expressed on the tumor cell cytoplasm. Of 62 tumors, 44 (77%) were weak to strong postive for VEGF, but 18 cases were not reactive. VEGF positivity was correlat-ed with WHO grades of the astrocytic tumors; low grade astrocytomas (52%), anaplastic astrocytomas (83%), and glioblastomas (96%). Mean microvessel count and density were significantly higher in VEGF-positive tumors (75.7 and 4.1%) than in VEGF-negative tumors (43.9 and 2.5%). Apoptotic cells were readily found in the astrocytic tumors; the highest value of AI was observed in glioblastomas (8.6%) and the lowest in anaplastic astrocytomas (1.9%). It seemed that the grade of malignancy was not related with AI values.
CONCLUSIONS
These results suggest that VEGF promotes angiogenesis with tumor cell growth against apoptotic cell death in the human astrocytomas.