Ependymoma with RELA fusion has been defined as a novel entity of the revised World Health Organization 2016 classification of tumors of the central nervous system (CNS), characterized by fusion transcripts of the RELA gene and consequent pathological activation of the NFkB pathway.
DAL-1, a related tumor suppressor and protein 4.1 family member on 18p11.3, has also been recently implicated in meningioma pathogenesis, though its role in ependymoma remains unknown.
RASSF1A hypermethylation represents the most common gene-specific defect identified in ependymoma highlighting the importance of its further investigation in this disease.
Calcyphosine immunoreactivity was observed in 59% of the ependymomas and was most profound in ependymoma tissue showing epithelial differentiation. mRNA expression levels of stathmin, annexin A1, and calcyphosine significantly correlated (Rs = 0.65 [p < 0.0001], Rs = 0.50 [p = 0.001], and Rs = 0.72 [p < 0.0001], respectively) with protein expression levels.
LGA mRNA expression was relatively very low in cultured astrocytes, and very low to absent in astrocytoma pilocyticum, ependymoma and subependymal giant cell astrocytoma (SEGA), tumors of astrocytic origin.
C11orf95-RELA fusion proteins translocated spontaneously to the nucleus to activate NF-κB target genes, and rapidly transformed neural stem cells--the cell of origin of ependymoma--to form these tumours in mice.
NHERF1 staining was present in 35% of ependymoma cases that lacked reactivity for EMA, the routine immunohistochemical marker used for ependymoma diagnosis.
NOTCH1 expression in ST-EPN was correlated with the CSCs markers VEGFA and L1CAM overexpression and JAG1 expression was correlated with the CCND1 and CDK6 overexpression.