Clinicopathologic application of lectin histochemistry: bisecting GlcNAc in glioblastoma

Glycosylation is one of the most common posttranslational modifications and changes in oligosaccharide structures are associated with many human diseases including a number of cancers. Thus, discovering aberrant glycosylation patterns that serve as markers for brain tumor progression and metastasis represents an attractive strategy to improve clinicopathologic diagnosis and to provide aids to the development of novel therapies. To identify glioblastoma (GBM) cells expressing glycoproteins that contain high levels of the bisecting N-acetylglucosamine (GlcNAc) structures, lectin histochemistry was carried out using erythroagglutinating phytohemagglutinin. Although GBM frequently expressed the bisecting GlcNAc, the lectin reactivity varied among tumor regions within individual specimens. Since detailed histopathologic analysis revealed that oligosaccharides with bisecting GlcNAc structures were preferably expressed in tumor regions with low KI67 immunopositivity, immunodetection of the bisecting GlcNAc could be useful to indicate less proliferative regions in human GBM. Our study highlights the potential use of lectin histochemistry to develop new methods for diagnosis that would improve future antiglioma therapy.