Differences in vascular endothelial growth factor receptor expression and correlation with the degree of enhancement in medulloblastoma

2014 ◽  
Vol 14 (2) ◽  
pp. 121-128 ◽  
Author(s):  
Shawn L. Hervey-Jumper ◽  
Hugh J. L. Garton ◽  
Darryl Lau ◽  
David Altshuler ◽  
Douglas J. Quint ◽  
...  

Object Vascular endothelial growth factor (VEGF) is the major proangiogenic factor in many solid tumors. Vascular endothelial growth factor receptor (VEGFR) is expressed in abundance in pediatric patients with medulloblastoma and is associated with tumor metastasis, poor prognosis, and proliferation. Gadolinium enhancement on MRI has been suggested to have prognostic significance for some tumors. The association of VEGF/VEGFR and Gd enhancement in medulloblastoma has never been closely examined. The authors therefore sought to evaluate whether Gd-enhancing medulloblastomas have higher levels of VEGFR and CD31. Outcomes and survival in patients with enhancing and nonenhancing tumors were also compared. Methods A retrospective analysis of patients with enhancing, nonenhancing, and partially enhancing medulloblastomas was performed. Primary end points included risk stratification, extent of resection, and perioperative complications. A cohort of 3 enhancing and 3 nonenhancing tumors was selected for VEGFR and CD31 analysis as well as microvessel density measurements. Results Fifty-eight patients were analyzed, and 20.7% of the medulloblastomas in these patients were nonenhancing. Enhancing medulloblastomas exhibited strong VEGFR1/2 and CD31 expression relative to nonenhancing tumors. There was no significant difference in perioperative complications or patient survival between the 2 groups. Conclusions These results suggest that in patients with medulloblastoma the presence of enhancement on MRI may correlate with increased vascularity and angiogenesis, but does not correlate with worse patient prognosis in the short or long term.

2001 ◽  
Vol 100 (5) ◽  
pp. 567-575 ◽  
Author(s):  
Funmi M. BELGORE ◽  
Andrew D. BLANN ◽  
Gregory Y. LIP

Vascular endothelial growth factor (VEGF) mediates endothelial cell mitogenesis and enhances vascular permeability. VEGF interacts with the endothelium via two membrane-spanning receptors, fms-like tyrosine kinase (Flt)-1 and kinase domain receptor. A soluble form of Flt-1 (sFlt-1) was isolated from endothelial cell media; however, its biological significance is still unknown, with limited data on plasma sFlt-1 levels in disease states. We have developed two new ELISAs for detecting free and VEGF-complexed sFlt-1, which were tested in accordance with standard validation and assessment methodologies employed in commercial settings. The intra-and inter-assay coefficients of variation are < 5% and 10% respectively, and results are highly reproducible. Applying these ELISAs in a clinical setting, we measured levels of VEGF, free and complexed sFlt-1 in citrated plasma from 40 patients with cardiovascular disease and 40 healthy controls. Median (interquartile range) plasma levels of VEGF in patients were significantly greater than controls [403 pg/ml (158–925 pg/ml) versus 113 pg/ml (33–231 pg/ml), P ⩽ 0.05]. Free sFlt-1 was significantly lower in patients compared with controls [8 ng/ml (2–22 ng/ml) versus 21 ng/ml (10–73 ng/ml), P ⩽ 0.05]. There was no significant difference in the levels of complexed sFlt-1 between the two groups. Plasma levels of VEGF-complexed sFlt-1 are minimal, despite the presence of excess free sFlt-1. Thus unbound plasma VEGF detected by ELISA may represent the majority of circulating VEGF, and justifies the measurement of plasma VEGF as an indicator of circulating VEGF levels. Furthermore, these results suggest that circulating sFlt-1 may serve as a selective inhibitor of VEGF activity, and that this regulatory mechanism may be altered by pathological conditions.


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