Adult Glioblastoma and the Role of DAXX (Death Domain Associated Protein) Tumor Biomarker

Abstract

It has been definitively established in pediatric research studies that DAXX negatively regulates genes involved in oncogenesis [4]. With genome sequencing identifying mutations in the H3.3-ATRX-DAXX chroma-tin remodeling pathway in 44% of the pediatric GBM tumors [8]. However, there has been limited research examining the role of DAXX in adult GBM. No large studies have identified DAXX mutations or protein expression in an adult GBM cohort. This could be because genetic alterations of DAXX are seen to be uncommon in adult GBM. It is possible that DAXX may play a role in adult GBM tumors in a similar manner to that established in pediatric models. Materials and Methods Design This study is a retrospective study of the histopathol-ogy and the biomarker expression of the patients who were diagnosed with Glioblastoma at the department of pathology and laboratory medicine, Zucker School of Medicine at Hofstra Northwell. 72 cases of GBM were included in our study. An immunohistochemical method for DAXX determination (Anti-DAXX) was performed to determine protein expression. Factors including MRI size and survival status were compared to different co-horts of Daxx-1 expression. These cohorts include limited expression < 25% and definite expression (> 25%) which were quantified according to overall, cytoplasmic and nuclear staining percentages.