Expression of the Chondroitin Sulphate Proteoglycan, NG2, in Paediatric Brain Tumors

Background/Aim: While neuron-glia 2 (NG2) is well-characterized in the developing brain and in adult high- grade gliomas, little is known about NG2 expression in paediatric brain tumors. Here, NG2 expression was examined in a range of paediatric brain tumors. Materials and Methods: A retrospective immunohistopathological analysis of 57 paediatric brain tumor biopsies of various tumor types was carried out. Paediatric cell lines, including two medulloblastomas and one dysembryoplastic neuroepithelial tumor, in addition to one adult high-grade glioma, were also assessed for NG2 expression. Results: NG2-positive staining was seen in all dysembryoplastic neuroepithelial tumors (DNETs) examined; however, only two of the fourteen medulloblastomas examined were NG2- positive. Compared to adult glioma, there was a lack of NG2 staining in the vasculature of paediatric brain tumors. Conclusion: NG2 expression in paediatric brain tumors differs depending upon type and, unlike adult glioma, includes expression on lower-grade tumors. Neuron-glia 2 (NG2), also known as CSPG4, is a chondroitin sulphate proteoglycan that has been well-characterized in the developing human brain and in adult malignant primary brain tumors. Indeed, NG2 is often expressed in glioma cells, which are characterized by increased proliferation rates (1) and exhibit high tumorigenic capabilities with an aggressive molecular phenotype (2). Moreover, its expression has been shown to correlate with the degree of malignancy in high-