Ezh1 regulates expression of Cpg15/Neuritin in mouse cortical neurons.

Immature neurons undergo morphological and physiological maturation in order to establish neuronal networks. During neuronal maturation, a large number of genes change their transcriptional levels, and these changes may be mediated by chromatin modifiers. In this study, we found that the level of Ezh1, a component of Polycomb repressive complex 2 (PRC2), increases during neuronal maturation in mouse neocortical culture. In addition, conditional knockout of Ezh1 in post-mitotic excitatory neurons leads to downregulation of a set of genes related to neuronal maturation. Moreover, the locus encoding Cpg15/Neuritin (Nrn1), which is regulated by neuronal activity and implicated in stabilization and maturation of excitatory synapses, is a direct target of Ezh1 in cortical neurons. Together, these results suggest that elevated expression of Ezh1 contributes to maturation of cortical neurons.

Anxiety is associated with higher levels of global DNA methylation and altered expression of epigenetic and interleukin-6 genes.

OBJECTIVES: Anxiety is associated with elevated levels of the inflammatory cytokine interleukin-6 (IL-6) and an increased risk for diseases with an inflammatory aetiology. In cancer, higher levels of IL-6 have been associated with increased expression of the epigenetic enzymes DNMT1 and Enhancer of Zeste Homolog 2 (EZH2). However, the relationship between IL-6 and DNA methyltransferases (DNMTs) and EZH2 expression has not previously been examined in anxious individuals. METHODS: Global DNA methylation levels were measured using the Methylflash Methylated DNA Quantification Kit and gene expression levels of the DNMT and EZH2 genes in anxious (n=25) and nonanxious individuals (n=22) were compared using quantitative real-time PCR. Specifically, we investigated whether global DNA methylation or aberrant expression of these genes was correlated with IL-6 mRNA and protein serum levels in anxious individuals. RESULTS: Anxious participants had significantly higher levels of global DNA methylation compared with controls (P=0.001). There were no differences in the mean mRNA expression levels of the DNMT1/3A/3B, EZH2 and IL-6 genes in anxious individuals compared with controls. However, the expression of DNMT1/3A, EZH2 and IL-6 genes increases with increasing Hospital Anxiety and Depression Scale-Anxiety scores in the anxious cohort only. Interestingly, IL-6 gene expression was correlated strongly with DNMT1/3A/3B and EZH2 expression, highlighting a potential relationship between IL-6 and important epigenetic regulatory enzymes. CONCLUSION: This study provides novel insight into the relationship between anxiety, epigenetics and IL-6. Moreover, our findings support the hypothesis that changes in DNA methylation profiles may contribute to the biology of anxiety.

DOC-2/DAB2 interacting protein status in high-risk prostate cancer correlates with outcome for patients treated with radiation therapy.

PURPOSE: This pilot study investigates the role of DOC-2/DAB2 Interacting Protein (DAB2IP) and enhancer of zeste homolog 2 (EZH2) as prognostic biomarkers in high-risk prostate cancer patients receiving definitive radiation therapy. METHODS AND MATERIALS: Immunohistochemistry was performed and scored by an expert genitourinary pathologist. Clinical endpoints evaluated were freedom from biochemical failure (FFBF), castration resistance-free survival (CRFS), and distant metastasis-free survival (DMFS). Log-rank test and Cox regression were used to determine significance of biomarker levels with clinical outcome. RESULTS: Fifty-four patients with high-risk prostate cancer (stage ≥ T3a, or Gleason score ≥ 8, or prostate-specific antigen level ≥ 20 ng/mL) treated with radiation therapy from 2005 to 2012 at our institution were evaluated. Nearly all patients expressed EZH2 (98%), whereas 28% of patients revealed DAB2IP reduction and 72% retained DAB2IP. Median follow-up was 34.0 months for DAB2IP-reduced patients, 29.9 months for DAB2IP-retained patients, and 32.6 months in the EZH2 study. Reduction in DAB2IP portended worse outcome compared with DAB2IP-retained patients, including FFBF (4-year: 37% vs 89%, P=.04), CRFS (4-year: 50% vs 90%, P=.02), and DMFS (4-year: 36% vs 97%, P=.05). Stratified EZH2 expression trended toward significance for worse FFBF and CRFS (P=.07). Patients with reduced DAB2IP or highest-intensity EZH2 expression exhibited worse FFBF (4-year: 32% vs 95%, P=.02), CRFS (4-year: 28% vs 100%, P<.01), and DMFS (4-year: 39% vs 100%, P=.04) compared with the control group. CONCLUSION: Loss of DAB2IP is a potent biomarker that portends worse outcome despite definitive radiation therapy for patients with high-risk prostate cancer. Enhancer of zeste homolog 2 is expressed in most high-risk tumors and is a less potent discriminator of outcome in this study. The DAB2IP status in combination with degree of EZH2 expression may be useful for determining patients with worse outcome within the high-risk prostate cancer population.

Aberrant histone methylation in the patients with immune thrombocytopenia.

Abstract The aim of the present study was to investigate alterations in histone methylation in patients with primary immune thrombocytopenia (ITP). Global histone H3K4/H3K9 methylation in CD4+ T cells from 35 ITP patients and 15 healthy controls were measured using the EpiQuik(TM) global histone H3K4/H3K9 methylation assay kits. The mRNA expression of SUV39H1, SUV39H2 and EZH2 were detected by real-time quantitative polymerase chain reaction (RT-PCR). The results showed that global histone H3K9 hypomethylation in CD4+ T cells of active ITP, compared with ITP in remission and controls, while the global histone H3K4 methylation were not significantly different between ITP patients and healthy controls. The expression of EZH2 and SUV39H2 were significantly down-regulated in active ITP patients, when compared with ITP in remission and controls. There were not different between ITP patients and controls in the expression SUV39H1. In conclusion, the aberrant histone methylation was involved in the pathogenesis of ITP.

The end of the road for prostate specific antigen testing?

Many candidate biomarkers for diagnosis of prostate cancer have been investigated, but prostate-specific antigen (PSA) testing remains the frontline test for both mass screening and individual clinical testing. Although the PSA test is cost-effective, analytically reliable, and flexibly high throughput, it has a very weak correlation with prostate malignancy. This has resulted in over-diagnosis and over-treatment of patients leading to costly economic, social, and psychological impacts. PSA testing lacks the ability to molecularly characterize prostate diseases and define aggressiveness and lethality, which are necessary to influence choice of treatment. Therefore, newer molecular tests are beginning to replace the PSA tests. The prostate cancer antigen 3 test has shown superiority and is now widely used. The recently reported sarcosine urine test, the already delineated TMPRSS2: ETS fusion genes, the glutathione-S-transferase P1 serum marker, and enhancer of zeste homolog 2 biomarker may also help improve diagnosis and prognostication of prostate cancer. The analytical trend is toward a multiplex testing format using molecular and/or proteomic techniques that are reliable, accurate, reproducible, and ensure rapid quantitation. Therefore, validation of these newer biomarkers and their assays are necessary for both large-scale clinical trials and clinical utility.