Expressions of Aquaporin4, VEGFR1 and the pattern of genetic aberrations in meningiomas have no influence on the peritumoral edema

Abstract

Objective: Despite the frequently reported assumption that VEGFR and Aquaporin4 (AQP4) expression seem to correlate with peritumoral brain edema formation in meningiomas, the molecular pathogenesis of edema formation is still elusive. Therefore, the authors analyzed meningioma edema formation in correlation to typical chromosomal deletions and the expression of VEGFR and Aquaporin4. Methods: Tissue specimens of 69 meningiomas were obtained from surgery between 2008 and 2010. Locus specific FISH analysis detecting the chromosomes 1, 9, 14, 18 and 22 were performed. Moreover, immunoblotting was performed to detect the expression of VEGFR1 and VEGFR2. Aquaporin4 expression was investigated by ELISA. The results were correlated with the peritumoral brain edema in the preoperative MRI. Statistical analysis including Pearson correlation and multivariate statistical analysis was performed. Results: In contrast to previous reports, a significant correlation to the brain edema in meningiomas could be identified only for VEGFR2 ( p <.01). Progression associated aberrations of chromosomes 1, 9, 14, 18 and 22 showed no correlation with the expression of VEGFR1, VEGFR2 and AQP4. AQP4 had nosignificant impact on brain edema formation as well. Conclusions: The current data confirm a strong correlation of VEGFR expression with formation of peritumoral brain edema only for VEGFR2. Moreover, neither the expression of VEGFR1, nor the expression of VEGFR2 nor the expression of AQP4 did correlate with any specific chromosomal aberrations. The molecular actors which can induce a peritumoral brain edema in meningiomas remain widely unclear.