Microvascular density through the expression of CD 105 (Endoglin) and CD 31 and correlation with VEGF and proliferative index (Ki 67) in Glioblastoma

Background and Objectives:Angiogenesis is essential for growth and metastasis of solid malignancies. Tumor vesselcount and expression of vascular endothelial growth factor (VEGF), a potent angiogenicfactor, have been associated with prognosis. This study was designed to assess vesselsdensity by using CD31 and CD105 (Endoglin) and their correlation with expression of VEGFand proliferative index (Ki67) in Glioblastoma multiforme (GBM).Materials and Methods:We examined these parameters in GBM specimens from 50 adult patients, reffered to Al-Zahra hospital pathology lab between 2001 to 2006.These patient did not receive preoperativetherapy. Paraffin-embedded tumour specimens were immunohistochemicallystained for CD31, CD105 (Endoglin), VEGF and Ki67 (proliferation index) monoclonalantibodies. Microvessel density (MVD) was evaluated by immunostaining for CD31 andCD105.Then the results were compared between the two and also with VEGF receptors andKi67 index.Results:We showed that CD105-MVD was significantly higher in Glioblastoma compared withperitumoral normal (14.28 vs. 6.68: P=0.012). We did not find such difference for CD31. Themean of CD105-MVD was significantly higher than CD31-MVD in Glioblastoma tissue(P<0.001) although there was a significant positive relationship between them (Pearson sr=0.630 P<0.001).The VEGF scoring for tumoral tissue was 12% (score: 1), 46% (score: 2)and 42% (score: 3).For peritumoral normal tissue were 92% (score: 1) and 8% (score: 2) . Sothey reach to statistical significance (Chi Square, P = 0001).Both MVD of CD105 and CD31have significant relationship with VEGF (P<0.001).Conclusion:We suggest that Endoglin can be used as a specific and sensitive marker for evaluation ofangiogenesis in Glioblastoma which can be used in the diagnosis and treatment of this tumor.Keywords: CD105 (Endoglin), CD31, Angiogenesis, Glioblastoma Multiforme (GBM),Vascular Endothelial Growth Factor (VEGF).