Overexpression of EZH2 is associated with clinicopathological parameters and poor prognosis in gliomas.

Abstract

The histone methyltransferase enhancer of zeste homolog 2 (EZH2), which is primarily localized in the nucleus, mediates Polycomb repressive complex activity by trimethylating lysine 27 of histone H3 (H3K27me3), thereby leading to transcriptional silencing. EZH2 plays a crucial role in cell proliferation, differentiation and apoptosis. Its overexpression is frequently observed in various cancers and contributes to tumor progression. A potential prognostic role for EZH2 in glioma has been suggested. The present study aimed to evaluate the clinicopathological and prognostic significance of EZH2 expression in glioma. EZH2 mRNA levels in tumor and normal tissues were assessed using the TIMER2.0 and The Cancer Genome Atlas databases. The prognostic value of EZH2 mRNA expression was analyzed using the Kaplan-Meier plotter. Immunohistochemistry was performed on 147 clinical glioma samples to evaluate EZH2 protein expression. Cox proportional hazards models and Kaplan-Meier survival curves were used to examine the associations between EZH2 expression, clinicopathological parameters and overall survival (OS). EZH2 was significantly upregulated and amplified in tumor tissues across multiple cohorts. In high-grade gliomas, elevated EZH2 expression was significantly associated with poorer OS, disease-specific survival and progression-free interval. The results of the present study indicated that EZH2 expression may serve as a valuable prognostic biomarker in glioma.