Tissue Transglutaminase 2 Expression and Function in Glioblastoma

Abstract

Glioblastoma is the most common and aggressive type of adult brain tumour. It is currently incurable and requires more effective treatments. Tissue transglutaminase 2 (TGM2) has previously been suggested to have a role in glioblastoma. Previous studies focused on TGM2 expression and inhibition in glioblastoma cells. Here we were interested in TGM2 expression in glioblastoma-associated microglia/macrophages and in identifying the role it plays in the tumor microenvironment. Based on data from bioinformatics, cell culture experiments, immunohistochemistry and immunofluorescence on mouse samples and human samples, we have shown that glioblastoma-associated microglia/macrophages are the major source of TGM2 in the tumor microenvironment. We also identified a novel role for TGM2 in efferocytosis in glioblastoma; this suggests a role for TGM2 in the maintenance of an immunosuppressive environment in this cancer. With this, we hope that further studies will be designed to evaluate the use of TGM2 antagonists as therapeutic agents for glioblastoma.