RESUMO
Objective:To investigate the expressions and significance of tyrosine kinase receptor EphA2 and its ligand ephrinA1 in human malignant gliomas and their correlation with tumor angiogenesis. Methods:The expressions of EphA2, ephrinA1, and CD105-stained microvessel density (MVD) were detected via immunohistochemical assay in 62 glioma tissues and 8 normal brain tissues. The correlation between EphA2 and ephrinA1 expression and microvessel counts in the glioma tissues were assessed. Results:Immunohistochemical staining results revealed that variable levels of EphA2 and MVD expression were significantly higher than that of the normal brain samples. Statistical difference was observed in EphA2 and MVD expressions between human gliomas and normal brain samples (P<0.01). The positive rate of EphA2 and MVD expressions was significantly higher in high-grade gliomas (WHO III-IV) than that in low-grade gliomas (WHO I-II) (P<0.01). EphrinA1 was expressed at low levels in most malignant gliomas, and the increased ephrinA1 expression was associated with lower-grade histology. MVD was significantly positively correlated with EphA2 expression (r=0.713, P<0.01) and significantly negatively correlated with ephrinA1 expression (r=-0. 772, P<0.01). EphA2 was significantly negatively correlated with ephrinA1 expression (r=-0.912, P<0.01). Conclusion:Specifically over-expressed EphA2 and its low-expressed ligand ephrinA1 in malignant gliomas may be closely correlated with the invasion and malignant degree of gliomas. Cooperation is involved in the angiogenesis and has an important function in the initiation and progression of gliomas.