Variable expression of CXCR4 in molecular subtypes of infiltrating gliomas.

Abstract

Glioblastomas (GBMs) and diffuse intrinsic pontine gliomas (DIPGs) are infiltrating gliomas with poor prognosis. CXCR4 has been linked to glioma cell invasion, survival, proliferation, and angiogenesis. This study aimed to evaluate the expression of CXCR4 in molecular subtypes of adult and pediatric infiltrating gliomas. We evaluated the expression of CXCR4 in 21 DIPGs and 44 adult infiltrating gliomas (25 GBM, 8 astrocytomas, and 11 oligodendrogliomas) by immunohistochemistry. Mutations in 315 cancer genes and rearrangements in 28 genes were evaluated by next-generation sequencing. CXCR4 was expressed in -DIPGs and adult infiltrating gliomas in tumor cells (28.6% and 5.6%, respectively) and endothelial cells (14.3% and 19.4%?, respectively). In adult gliomas, there was a correlation between CXCR4 expression and mutations in EGFR, PIK3CA, TERT promoter, and CDKN2A/B loss. In contrast, CXCR4 expression was not detected in IDH1/IDH2 mutant gliomas. These associations were confirmed using The Cancer Genome Atlas (TCGA) database. CXCR4 is expressed in a subset of DIPGs and GBMs, but it is not expressed in astrocytomas or oligodendrogliomas. CXCR4 expression is variable and it is influenced by tumor genomic alterations. It is important to consider CXCR4 expression in clinical trials that evaluate the efficacy of CXCR4 inhibitors in the treatment of gliomas.