Published in:
01-03-2008 | Original Paper
Expression of the polycomb group protein EZH2 and its relation to outcome in patients with urothelial carcinoma of the bladder
Published in: Journal of Cancer Research and Clinical Oncology | Issue 3/2008
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Purpose
The polycomb group protein Enhancer of Zeste Homolg 2 (EZH2), a repressor of gene transcription, has been linked to the progression of various malignancies. This study was done to examine a potential correlation of EZH2 mRNA expression with clinicopathological parameters and outcome in patients with urothelial carcinoma (UC) of the bladder.
Methods
We determined the relative EZH2 gene expression by quantitative RT-PCR in tumor specimens from a cohort of 100 patients with UC (mean follow-up 44.2 months). EZH2 expression levels were correlated to pathological tumor features and outcome.
Results
Enhancer of Zeste Homolg 2 was expressed in 90% of the tumor samples. Expression levels increased in parallel with tumor stage (P = 0.002). High grade UC displayed significantly elevated EZH2 levels compared to low grade disease (P < 0.0001). High EZH2 expression was related to an abbreviated time to recurrence in muscle invasive carcinomas (pT ≥ 2) (P = 0.028). No such correlation was detected in the group of superficial tumors (pT ≤ 1) (P = 0.191). High EZH2 expression levels were associated with an increased risk of tumor related death in the univariate analysis (relative risk, 3.1; P = 0.029). This association became non-significant when the prognostic effect of tumor stage was considered in a multivariate model.
Conclusions
Enhancer of Zeste Homolg 2 expression is related to an aggressive tumor behavior but due to its strong association with pathological features, EZH2 levels do not provide independent prognostic information.