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Abstract Background Global histone modifications have been implicated in the progression of various tumour entities. Our study was designed to assess global methylation levels of histone 4 lysine 20 (H4K20me1-3) at different stages of prostate cancer (PCA) carcinogenesis. Methods Global H4K20 methylation levels were evaluated using a tissue microarray in patients with clinically localized PCA (n = 113), non-malignant prostate disease (n = 27), metastatic hormone-naive PCA (mPCA, n = 30) and castration-resistant PCA (CRPC, n = 34). Immunohistochemistry was performed to assess global levels of H4K20 methylation levels. Results Similar proportions of the normal, PCA, and mPCA prostate tissues showed strong H4K20me3 staining. CRPC tissue analysis showed the weakest immunostaining levels of H4K20me1 and H4K20me2, compared to other prostate tissues. H4K20me2 methylation levels indicated significant differences in examined tissues except for normal prostate versus PCA tissue. H4K20me1 differentiates CRPC from other prostate tissues. H4K20me1 was significantly correlated with lymph node metastases, and H4K20me2 showed a significant correlation with the Gleason score. However, H4K20 methylation levels failed to predict PSA recurrence after radical prostatectomy. Conclusions H4K20 methylation levels constitute valuable markers for the dynamic process of prostate cancer carcinogenesis.

Purpose: Earlier studies indicate that epigenetics contribute to the pathogenesis of penile squamous cell carcinoma. Histone methylation patterns are frequently altered during carcinogenesis. Therefore, we investigated the methylation pattern of the histones H3K4, H3K9 and H3K27 in penile carcinoma and normal tissue. Materials and Methods: A tissue microarray was constructed with 65 penile carcinomas, 6 metastatic lesions and 30 control tissues. Global histone methylation was assessed using immunohistochemistry. Results: Global levels of H3K4me1, H3K9me1, H3K9me2, H3K27me2 and H3K27me3 were decreased, whereas H3K9me3 was increased in penile carcinoma. Histone methylation levels defined an epigenetic entity that allowed accurate differentiation of cancer and normal samples. We observed no correlation of histone methylation levels with clinicopathological parameters or patient outcome. Conclusions: The description of a definite epigenetic entity in penile carcinoma provides a rationale for testing epigenetic agents in patients with metastatic disease. [ABSTRACT FROM AUTHOR]

Global histone modification patterns have been shown to be a predictive factor of recurrence in various cancers. We analyzed global histone-3-lysine-27 (H3K27) methylation in prostate cancer (PCA) tissues. H3K27 mono-, di-, and tri-methylation patterns were different in nonmalignant prostate tissue, localized PCA, metastatic PCA, and castration-resistant PCA. H3K27 mono-methylation was correlated with pT-stage, capsular penetration, seminal vesicle infiltration, and Gleason score in localized PCA and may therefore indicate adverse prognosis. [ABSTRACT FROM AUTHOR]

What's known on the subject? and What does the study add? Epigenetic alterations are important during carcinogenesis, and earlier studies suggested that global histone modification levels are predictive for patients' outcome in various tumor entities. We demonstrate that H3K27me1 and H3K27me3 are markers of progression-free survival in patients with renal cell carcinoma. OBJECTIVE • To evaluate if histone H3 lysine 27 (H3K27) methylation plays a role in renal cell carcinoma (RCC) tissue and whether its expression is a predictor of cancer recurrence in RCC. MATERIALS AND METHODS • A tissue microarray (TMA) with 193 RCC specimens (comprising 142 clear-cell, 31 papillary, 10 chromophobe and 10 sarcomatoid RCC), 10 oncocytoma tissue specimens and a TMA with 30 benign renal tissue samples were stained with antibodies against H3K27-monomethyl (H3K27me1), H3K27-dimethyl (H3K27me2) and H3K27-trimethyl (H3K27me3). • Sections were scored according to staining intensity and the proportion of epithelial cells showing nuclear staining. • H3K27 methylation levels were correlated with established clinical-pathological variables (tumour-node-metastasis [TNM] stage, Fuhrman grade) and progression-free/cancer-specific survival. RESULTS • H3K27me1/-me2/-me3 staining was significantly more intense in papillary RCC then in clear-cell RCC. • H3K27me3 levels were higher in oncocytoma than in RCC. • H3K27me1/-me2/-me3 methylation levels were inversely correlated with Fuhrman grading and pT-stage. • Global H3K27me1/-me2/-me3 methylation levels were always higher in benign renal tissue than in RCC with tumour relapse (H3K27me1 P < 0.001, H3K27me2 P= 0.032, H3K27me3 P= 0.004). • Progression-free survival was shorter in patients with lower levels of H3K27me1 and H3K27me3 in the univariate analysis. The newly created H3K27me score (combining the staining levels of the single modifications) was a significant and independent predictor of RCC progression-free survival. CONCLUSION • The present study on H3K27-methylation supports the hypothesis that global histone modifications are potential markers of cancer prognosis in RCC. One reason could be that decreased H3K27 indicates transcriptional activation and therefore predicts cancer activation. [ABSTRACT FROM AUTHOR]

Study Type - Prognosis (case series) Level of Evidence 4 What's known on the subject? and What does the study add? Epigenetic alterations play an essential role during carcinogenesis. While DNA methylation has been extensively studied in bladder cancer, the relevance of histone modifications remains to be clarified. Earlier studies suggested that global histone modification levels are predictive for patients' outcome in various tumour entities (e.g. prostate, lung, breast and kidney cancer). The possibility to determine global histone modification levels easily and inexpensively using immunohistochemistry increases a potential routine use in the future. Our aim was therefore to investigate the global levels of histone H3K4 and H4K20 mono-, di- and trimethylation. For this purpose we prepared tissue microarrays with non-muscle-invasive bladder cancer (NMIBC), muscle-invasive bladder cancer (MIBC), bladder cancer metastases (METS) and normal urothelium (NU) tissue to compare global H3K4 and H4K20 methylation in these tissues, as well to assess the prognostic value of histone modifications. We show that global histone modification levels (H3K4me1, H3K4me3, H4K20me1, H4K20me2, H4K20me3) are lower in bladder cancer than in NU tissue. Furthermore, there was a decrease of histone modification levels (H3K4me1, H4K20me1, H4K20me2, H4K20me3) from NU over NMIBC and MIBCto METS. Histone modifications are correlated to advanced pathological stage in NMIBC and MIBC. Furthermore, H4K20me3 appeared to be a significant and independent prognostic predictor of bladder cancer-specific survival in patients with MIBC undergoing radical cystectomy. Our findings therefore provide a rationale for further investigation of histone modifications and their manipulation in bladder cancer. OBJECTIVE • To determine the role of global histone methylation as a prognostic parameter in patients with bladder cancer. PATIENTS AND METHODS • We used a tissue microarray with samples from patients with non-muscle-invasive bladder cancer (NMIBC; n= 161), muscle-invasive bladder cancer (MIBC, n= 127), normal urothelium (NU; n= 31) and bladder cancer metastases (METS; n= 31) to determine global histone methylation (me) levels at histone H3 lysine 4 (H3K4) and H4K20. RESULTS • Global histone modification levels (H3K4me1, H3K4me3, H4K20me1, H4K20me2, and H4K20me3) were lower in bladder cancersamples than in NU tissue • Global levels of H3K4me1, H4K20me1, H4K20me2 and H4K20me3 were decreasing from NU over NMIBC and MIBC to METS. • H4K20me1 levels were increased in patients with NMIBC with advanced pTstage and less differentiated bladder cancer. • In patients with MIBC, pTstage was negatively correlated with H3K4me1, H4K20me1 and H4K20me2 levels. • H4K20me3 levels were significantly correlated in a univariate and multivariate model with bladder cancer-specific mortality after radical cystectomy in patients with MIBC. CONCLUSION • Global histone methylation levels may help to identify patients with bladder cancerwith poor prognosis after radical cystectomy. [ABSTRACT FROM AUTHOR]

Purpose: DNA hypermethylation is a common cancer associated alteration. We analyzed methylation patterns of cell-free serum DNA in patients with testicular cancer. Materials and Methods: Hypermethylation at APC, GSTP1, PTGS2, p14(ARF), p16(INK) and RASSF1A was analyzed using real-time polymerase chain reaction following methylation sensitive restriction endonuclease treatment in 73 patients with testicular cancer and 35 healthy individuals. Results: Hypermethylation was more common in patients with testicular cancer than in healthy individuals, including APC 57% and 6%, p16(INK) 53% and 17%, p14(ARF) 53% and 0%, RASSF1A 47% and 0%, PTGS2 45% and 0%, and GSTP1 25% and 0%, respectively (each p <0.01). Methylation frequencies at the investigated gene sites were similar in nonseminoma and seminoma cases (p >0.05). Diagnostic information was increased when multiple gene sites were analyzed in combination (ROC AUC 0.834, 67% sensitivity and 97% specificity). Diagnostic information was superior to the analysis of AFP/HCG/PLAP/LDH (combined sensitivity 58% and AUC 0.791). The sensitivity of hypermethylation in patients with unsuspicious conventional tumor markers was 71% (AUC 0.871, 97% specificity). Hypermethylation at PTGS2 was more common in patients with pT1 stage tumors (p = 0.011). Conclusions: The detection of hypermethylated cell-free serum DNA has the potential of a useful additional diagnostic parameter in patients with testicular germ cell cancer. Furthermore, in cases without conventional tumor marker increases testing CpG island hypermethylation in cell-free circulation DNA may improve the ability to detect early and/or recurrent testicular cancer. [Copyright &y& Elsevier]

Purpose: CpG island hypermethylation is a frequent event in bladder carcinogenesis and progression. We investigated the diagnostic and prognostic value of hypermethylation in cell-free serum DNA of patients with bladder cancer. Materials and Methods: The study cohort consisted of 45 patients with bladder cancer undergoing cystectomy and 45 with histologically confirmed benign prostatic hyperplasia serving as controls. Hypermethylation at APC, DAPK, GSTP1, PTGS2, TIG1 and Reprimo was analyzed using real-time polymerase chain reaction following methylation sensitive restriction endonuclease treatment. Results: Hypermethylation at the APC and GSTP1 promoter was detected in 59% of cases, whereas TIG1 (32%), PTGS2 (24%) and DAPK (2%) were less frequently hypermethylated. In the benign prostatic hyperplasia group 3 patients also harbored methylated GSTP1 DNA, whereas none of the other gene sites was methylated. Hypermethylation at APC, GSTP1 or TIG1 distinguished patients with bladder cancer and controls most accurately with 80% sensitivity and 93% specificity. Hypermethylation significantly correlated with prognostic unfavorable clinicopathological parameters, including APC with pT stage, GSTP1, or GSTP1 or TIG1 with multifocal bladder cancer and APC, or APC or TIG1 with surgical margin positivity. Bladder cancer specific mortality was significantly increased in patients with APC hypermethylation. Conclusions: The detection of hypermethylation in cell-free serum DNA provides valuable diagnostic and prognostic information that can still be improved by combining the results of 3 gene sites (APC, GSTP1 and TIG1). The presence of hypermethylated DNA in the serum of patients with bladder cancer is associated with a worse outcome. Our results suggest that measuring hypermethylation in the serum of patients with bladder cancer is a useful biomarker. [Copyright &y& Elsevier]

Gene silencing by promoter DNA hypermethylation is common in PCA. The role of HXKy methylation as an up-/downstream or parallel silencing mechanism is not yet clear. We analyzed HXKy methylation at gene sites that are aberrantly DNA-methylated in PCA (i.e. GSTP1, RARβ, APC and PTGS2). Cancerous (PC3, DU145, LNCaP) and benign prostate hyperplasia (BPH1) cell lines were studied using chromatin immunoprecipitation and methylation specific PCR. Gene expression was analyzed using quantitative RT-PCR. In PCA, histone modifications characteristic of gene repression (di-/tri-methylated H3K9, H3K27, H4K20) were predominantly observed at the studied gene sites and paralleled aberrant DNA hypermethylation. In BPH, no aberrant DNA hypermethylation and mostly histone modifications supporting active gene expression (H3K4, H3K79 di-/tri methylation) were seen at the respective gene sites. Mono-methylated H3K4 and H3K9 modifications that have moderate effects on gene expression were frequent in both PCA and BPH. PC3 cells grown in the presence of the DNA methyltransferase inhibitor 5-aza-2′-deoxycytidine (aza) resulted in DNA demethylation and moderate gene reexpression whereas repressive HXKy di-methylation increased 1.5-3 fold and tri-methylation was mostly unchanged. Removal of aza reverses gene expression. These findings suggest that HXKy methylation is upstream to DNA hypermethylation in PCA. [ABSTRACT FROM AUTHOR]

Cancer patients have increased levels of serum DNA fragments (SDF) compared to most patients with non-malignant disease and healthy individuals. In PCA, DNA hypermethylation is also frequently observed (>80%) at promoter CpG islands of GSTP1, PTGS2 and TIG1. Therefore we analysed hypermethylation of these genes in SDF from patients with PCA (n=168) and benign prostate hyperplasia (BPH; n=42) and controls (n=11) for information about the cellular origin of DNA. SDF concentrations and the hypermethylated fractions were analysed using a methylation-sensitive restriction enzyme based real-time PCR. SDF levels were significantly increased in PCA vs BPH vs controls (65 vs 20 vs 7 ng/mL; p<0.001). Hypermethylation of GSTP1, TIG1 or PTGS2 was more frequently detected in PCA than in BPH patients and controls (overall 47% vs 8% vs 0%; p<0.001), but did not exceed 10% of total DNA. SDF levels distinguished PCA from BPH patients with a sensitivity of 83% and specificity of 69%. The diagnostic significance of SDF was greater than that of hypermethylation data. In conjunction with SDF, hypermethylation numbers did not contribute any further information. Both SDF levels and the hypermethylation status were not correlated to advanced tumor stage or grade (p>0.05). In summary SDF is a promising diagnostic marker in PCA. It does not primarily originate from tumor cells but from apoptotic and necrotic cells surrounding the tumor. [ABSTRACT FROM AUTHOR]

Abstract: Gene silencing by epigenetic mechanisms is frequent in prostate cancer (PCA). The link between DNA hypermethylation and histone modifications is not completely understood. We chose the GSTP1 gene which is silenced by hypermethylation to analyze the effect of the histone deacetylase inhibitor depsipeptide on DNA methylation and histone modifications at the GSTP1 promoter site. Prostate cell lines (PC-3, LNCaP, and BPH-1) were treated with depsipeptide; apoptosis (FACS analysis), GSTP1 mRNA levels (quantitative real-time PCR), DNA hypermethylation (methylation-specific PCR), and histone modifications (chromatin immunoprecipitation) were studied. Depsipeptide induced apoptosis in PCA cells, but not a cell cycle arrest. Depispeptide reversed DNA hypermethylation and repressive histone modifications (reduction of H3K9me2/3 and H3K27me2/3; increase of H3K18Ac), thereby inducing GSTP1 mRNA re-expression. Successful therapy requires both, DNA demethylation and activating histone modifications, to induce complete gene expression of epigenetically silenced genes and depsipeptide fulfils both criteria. [Copyright &y& Elsevier]

Abstract: The presence of small amounts of circulating DNA in plasma was demonstrated 60 years ago. Since then, cell-free DNA has been tested for quantity, fragmentation pattern, and tumor-specific sequences in patients with various malignancies. Recent studies have shown that cell-free DNA levels are distinctly increased in most patients with prostate cancer (PCA) and that the DNA fragmentation pattern is different from healthy individuals and patients with benign prostate disease. The origin of this circulating DNA remains largely unknown, but it is established that a small fraction of the DNA is derived from the tumor itself, and genetic (allelic imbalances) and epigenetic (DNA methylation) alterations are regularly detected in patients with PCA. The detection of increased DNA levels and tumor-specific DNA sequences may provide diagnostic and prognostic information. The recent findings in the emerging field of cell-free DNA will be discussed. [Copyright &y& Elsevier]