BACKGROUND & OBJECTIVE: EphrinB2 is a novel angiogenic factor. EphrinB2 and its 
receptor EphB4 express in several kinds of tumor cells,and correlate with 
tumorigenesis and neoangiogenesis. This study was designed to explore the 
characteristics of EphB4 and EphrinB2 protein expression in astrocytomas.
METHODS: Double labelling immunofluorescence was used to detect co-expression of 
EphB4/EphrinB2 with glial fibrilary acid protein (GFAP)or CD34 protein in 35 
fresh glioma specimens, and 2 kinds of human glioma cell lines (CHG-5,and 
SHG-44).
RESULTS: EphB4/EphrinB2 and CD34 proteins co-expressed in some tumor stromal 
microvessels, and mainly localizing in endothelial cells. Co-expression of 
EphB4/EphrinB2 and GFAP proteins was also noticed in tumor cells,and 2 glioma 
cell lines. In poorly-differentiated SHG-44 cells, the average fluorescence 
intensity of EphB4 was 72.48+/-33.78,and that of EphrinB2 was 96.80+/-36.98, 
both higher than those in well-differentiated CHG-5 cells (56.7+/-21.7, and 
53.6+/-18.8). But the green fluorescence intensity of GFAP in SHG-44 cells was 
22.3+/-15.3, while in CHG-5 cells was 47.5+/-16.7.
CONCLUSION: Expressions of EphB4 and EphrinB2 proteins may be related to 
differentiation degree of tumor cells.