VEGF expression correlates with neuronal differentiation and predicts a favorable prognosis in patients with neuroblastoma

Wen-Chin Weng,Wang-Tso Lee,Hsinyu Lee,Yen-Lin Liu,Bo-Jeng Wang,Yueh-Chien Lin,Chien-Chin Chen,Ya-Hsuan Ho,Kuan-Hung Lin,Pei-Yi Wu,Yung-Feng Liao,Wen-Ming Hsu

doi:10.1038/s41598-017-11637-8

Abstract

Neuroblastoma (NB) is a childhood cancer with a low survival rate and great metastatic potential. Vascular endothelial growth factor (VEGF), an angiogenesis factor, has been found to be involved in CRT-related neuronal differentiation of NB cells. In this study, we further confirmed the role VEGF in NB through mouse xenograft model and clinical analysis from NB patients. In xenograft experiments, CRT overexpression effectively inhibited the tumor growth. In addition, the mRNA and protein levels of VEGF and differentiation marker GAP-43 were upregulated by induced CRT expression. However, no significant correlation between the expression level of VEGF and microvessel density was observed in human NB tumors, suggesting a novel mechanism of VEGF participating in NB tumorigenesis through an angiogenesis-independent pathway. In NB patients’ samples, mRNA expression levels of CRT and VEGF were positively correlated. Furthermore, positive VEGF expression by immunostaining of NB tumors was found to correlate well with histological grade of differentiation and predicted a favorable prognosis. In conclusion, our findings suggest that VEGF is a favorable prognostic factor of NB and might affect NB tumor behavior through CRT-driven neuronal differentiation rather than angiogenesis that might shed light on a novel therapeutic strategy to improve the outcome of NB.

Highlights

Neuroblastoma (NB) is the most frequently diagnosed malignancy in infancy and the second most common extracranial solid tumor in childhood in Taiwan[1, 2]
To better understand the role of Vascular endothelial growth factor (VEGF) expression in the angiogenesis, neuronal differentiation, as well as tumor behavior in NB, we investigated the expression of VEGF in human NB tumors, mouse xenografts, and NB cells
VEGF expression was positively correlated with CRT expression and other neuronal differentiation markers in human NB tumors, xenografts, and cells

Summary

Introduction

Neuroblastoma (NB) is the most frequently diagnosed malignancy in infancy and the second most common extracranial solid tumor in childhood in Taiwan[1, 2]. We have shown that CRT could positively regulate VEGF protein expression and secretion levels in condition media of various NB cell lines[10], and the evidence that blockage of VEGF signaling could suppress neuronal differentiation in CRT-overexpressed NB cells, indicates that VEGF could be involved in CRT-regulated neuronal differentiation and might predict a favorable tumor behavior in NB. VEGF-driven angiogenesis has been shown to play a critical role in the pathogenesis of NB formation and metastasis[14, 15], various studies demonstrate conflicting results regarding the role of VEGF in the tumor behavior of NB11, 12, 16–19. To better understand the role of VEGF expression in the angiogenesis, neuronal differentiation, as well as tumor behavior in NB, we investigated the expression of VEGF in human NB tumors, mouse xenografts, and NB cells.

Methods

Results

Conclusion