Non-cancerous Prostate Tissues Research Articles

Gelsolin-like actin-capping proteinis associated with patient prognosis, cellular apoptosis and proliferation in prostate cancer.

To investigate the role of gelsolin-like actin-capping protein (CapG) in prostate cancer (PCa). CapG expression and its correlation with clinicopathological characters and patient prognosis were analyzed in 76 cases of PCa by immunohistochemistryand qRT-PCR. Then, the influence of CapG downregulation on cell apoptosis and proliferation were assessed. CapG expression in PCa was significantly higher compared with those in matched adjacent noncancerous prostate tissues, and significantly correlated with clinicopathological characters. Survival analysis indicated that CapG could be an independent prognostic factor in PCa. Moreover, CapG depletion significantly affected cellular proliferation and apoptosis by regulating Caspase 6/Caspase 9/Bcl-2/p-Akt/Akt signaling pathway. CapG, as a potential biomarker in PCa, is associated with patient prognosis, cellular apoptosis and proliferation.

Quantitative diffusion-weighted imaging and dynamic contrast-enhanced characterization of the index lesion with multiparametric MRI in prostate cancer patients.

To compare a simplified intravoxel incoherent motion (sIVIM) model to commonly used monoexponential and biexponential models in the characterization of prostate cancer (PCa) and noncancerous prostate tissues, and to investigate combinations of diffusion-weighted imaging (DWI) measures with dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI)-derived parameters in MRI-visible index lesions, to facilitate PCa risk stratification. In this retrospective, Institutional Review Board (IRB)-approved study, 43 consecutive patients with PCa who had 3T MRI exams followed by radical prostatectomy were included. DWI and DCE parameters were measured from one index lesion per patient, and noncancerous central gland and peripheral zone. Logistic regression modeling was performed to select the optimal combination of DWI and DCE measurements for tumor risk assessment. All diffusion models showed the lowest diffusion coefficients in tumors, intermediate values in noncancerous central gland, and highest values in noncancerous peripheral zone (all P < 0.001). Ktrans and kep were higher in tumors compared to central gland (P < 0.005) and peripheral zone (P < 0.001). The initial area under the contrast concentration curve was higher in tumor than the peripheral zone (P < 0.001). The area under the receiver operating characteristic curve of the combined DWI and DCE parameters (0.78) was higher than its individual components (0.73 and 0.63, respectively) for discriminating low- and intermediate-to-high-risk tumors. The sIVIM model provided comparable results with fewer b-values and shorter image acquisition time. The combination of DWI and DCE measurements of MRI-visible index lesions improved the preoperative prostate cancer risk characterization compared to the individual parameters from either technique alone. 3 J. Magn. Reson. Imaging 2017;45:908-916.

Abstract 1100: Targeting ITGA3/ITGB1 signaling by tumor-suppressive microRNA-223 inhibits cancer cell migration and invasion in prostate cancer

Abstract BACKGROUNDS: Most patients initially respond to androgen-deprivation therapy, but eventually acquire resistance and progress to castration-resistant prostate cancer (CRPC). Several clinical trials for CRPC have shown limited benefits, eventually resulting in disease progression and metastasis. Our recent study of microRNA (miRNA) expression signature in CRPC revealed that miR-223 expression was significantly reduced in PCa tissues, suggesting miR-223 functions as a tumor suppressive miRNA in PCa cells. The aim of this study was to investigate the functional significance of miR-223 and to identify its regulated oncogenic genes in PCa. METHODS: Expression levels of miR-223 were evaluated in PCa clinical specimens and PCa cell lines (PC3 and PC3M) by quantitative real-time PCR methods. Gain-of-function studies (cell proliferation, migration and invasion assays) were performed using transfection of mature miR-223 into cancer cells. Genome-wide gene expression analysis and in silico analysis were applied to investigate molecular targets regulated by miR-223 in PCa cells. A luciferase reporter assay was carried out to determine whether 3’ UTR of target genes have actual biding sites for miR-223. To investigate the functional role of target genes in PCa cells, loss-of-function studies by silencing of these genes were performed. RESULTS: The expression levels of miR-223 were significantly reduced in PCa clinical specimens and cell lines compared to non-cancerous prostate tissues. Restoration of miR-223 significantly inhibits cancer cell migration and invasion in PCa cells. Integrin alpha-3 (ITGA3) and integrin beta-1 (ITGB1) were identified as direct target genes of miR-223 by microarray, in silico studies, and luciferase reporter assays. ITGA3 and ITGB1 interact with multiple extracellular matrix proteins and mediate several survival signaling into the cancer cells. Knockdown of ITGA3 and ITGB1 significantly inhibited cancer cell migration and invasion in PCa cells by regulating downstream signaling. CONCLUSIONS: Downregulation of miR-223 was a frequent event of PCa cells and it functions as a tumor suppressor via targeting ITGA3 and ITGB1. Overexpression of ITGA3 or ITGB1 might be contributed to PCa oncogenesis and metastasis. Elucidation of tumor-suppressive miR-223 regulated molecular pathways and targets could provide new information on potential therapeutic strategies in PCa. Citation Format: Ichiro Fukumoto, Akira Kurozumi, Yusuke Goto, Ryosuke Matsushita, Mayuko Kato, Rika Nishikawa, Shinichi Sakamoto, Tomohiko Ichikawa, Naohiko Seki. Targeting ITGA3/ITGB1 signaling by tumor-suppressive microRNA-223 inhibits cancer cell migration and invasion in prostate cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1100.

Reduced expression of the DNA glycosylase gene MUTYH is associated with an increased number of somatic mutations via a reduction in the DNA repair capacity in prostate adenocarcinoma.

8-Hydroxyguanine (8OHG), a major oxidative DNA lesion, is known to accumulate in prostate cancer; however, the status of one of its repair enzymes, MUTYH, in prostate cancer remains to be elucidated. In this study, we showed that the expression levels of MUTYH mRNA and protein were significantly lower in prostate cancer than in non-cancerous prostatic tissue by examining two independent, publicly available databases and by performing an immunohistochemical analysis of prostate cancer specimens obtained at our hospital, respectively. About two-thirds of the prostate cancers exhibited a reduced MUTYH expression. When the effect of reduced MUTYH expression in prostate adenocarcinoma on the somatic mutation load was examined using data from the Cancer Genome Atlas (TCGA) database, the numbers of total somatic mutations and somatic G:C to T:A mutations were significantly higher in the reduced MUTYH expression group than in the other group (P < 0.0001 and P = 0.0013, respectively). To determine the reason why reduced MUTYH expression leads to somatic mutation loads in prostate adenocarcinoma, we compared the DNA repair capacities between PC-3 prostatic cell line derived clones with different MUTYH expression levels. Both the capacities to cleave DNA containing adenine:8OHG mispairs and to suppress mutations caused by 8OHG were significantly lower in prostatic cell lines with lower MUTYH expression than in prostatic cell lines with higher MUTYH expression. These results suggested that reduced MUTYH expression is associated with somatic mutation loads via a reduction in DNA repair capacity in prostate adenocarcinoma. © 2016 Wiley Periodicals, Inc.

Association of microRNA-21 expression with clinicopathological characteristics and the risk of progression in advanced prostate cancer patients receiving androgen deprivation therapy.

Despite androgen deprivation therapy (ADT) remains the mainstay therapy for advanced prostate cancer (PCa), the patients have widely variable durations of response to ADT. Unfortunately, there is limited knowledge of pre-treatment prognostic factors for response to ADT. Recently, microRNA-21 (miR-21) has been reported to play an important role in development of castration resistance of CaP. However, little is known about the expression of miR-21 in advanced PCa biopsy tissues, and data on its potential predictive value in advanced PCa are completely lacking. In this study, paraffin-embedded prostate carcinoma tissues obtained by needle biopsy from 85 advanced PCa patients were evaluated for the expression levels of miR-21 by quantitative real-time PCR (qRT-PCR). In situ hybridization (ISH) analysis was performed to further confirm the qRT-PCR results. Kaplan-Meier analysis and Cox proportional hazards regression models were performed to investigate the correlation between miR-21 expression and time to progression of advanced PCa patients. Compared with adjacent non-cancerous prostate tissues, the expression level of miR-21 was significantly increased in PCa tissues (PCa vs. non-cancerous prostate: 1.3273 ± 0.3207 vs. 0.9970 ± 0.2054, P < 0.001). By and large, in ISH analysis miR-21 was expressed at a higher level in tumor areas than in adjacent non-cancerous areas. Additionally, PCa patients with higher expression of miR-21 were significantly more likely to be of high Gleason score and high clinical stage (P < 0.05). There was no significant association between miR-21 expression and the initial prostate-specific antigen (PSA) level or age at diagnosis. Moreover, Kaplan-Meier survival analysis found that PCa patients with high miR-21 expression have shorter progression-free survival than those with low miR-21 expression. Furthermore, Multivariate Cox analysis revealed both miR-21 expression status (P = 0.040) and clinical stage (P = 0.042) were all independent predictive factor for progression-free survival for advanced PCa. These findings suggest for the first time that the up-regulation of miR-21 may serve as an independent predictor of progress-free survival in patients with advanced PCa. Prostate 76:986-993, 2016. © 2016 Wiley Periodicals, Inc.

Protein regulator of cytokinesis 1 overexpression predicts biochemical recurrence in men with prostate cancer.

Protein regulator of cytokinesis 1 (PRC1) has been reported to be implicated into the completion of cytokinesis and is dys-regulated in a cancer-specific manner. However, it roles in human prostate cancer (PCa) remain unclear. In the current study, we aimed to investigate the expression pattern of PRC1 and its clinical significance in this malignancy. PRC1 protein expression in human PCa and non-cancerous prostate tissues was detected by immunohistochemistry, which was validated by microarray-based Taylor data at mRNA level. Then, the associations of PRC1 expression with clinicopathological features and clinical outcome of PCa patients were statistically analyzed. PRC1 expression in PCa tissues, at both mRNA and protein levels, were significantly higher than those in non-cancerous prostate tissues. In addition, the PCa patients with PRC1 overexpression more frequently had high Gleason score, advanced pathological stage, positive metastasis, short overall survival time and positive PSA failure than those with low Gleason score, early pathological stage, negative metastasis, long overall survival time and negative PSA failure (all P<0.05). Moreover, PRC1 expression was identified as an unfavorable prognostic factor of biochemical recurrence-free survival in PCa patients (P<0.001). These findings suggest that the aberrant expression of PRC1 may predict biochemical recurrence in men with PCa highlighting its potential as a prognostic marker of this malignancy.

Detection of miRNAs in urine of prostate cancer patients

Background and aimProstate cancer (PCa) is the second most prevalent oncologic disease among men worldwide. Expression of various transcripts, including miRNAs, is markedly deregulated in cancerous prostate tissue. This study aimed at identifying a PCa-specific expression profile of miRNAs for subsequent use in noninvasive diagnostics. Materials and methodsMiRNA expression was profiled in 13 PCa tissues using human miRNA microarrays. Highly expressed miRNAs were selected for the analysis in urine of patients with PCa (N=143) and benign prostate hyperplasia (BPH; N=23) by means of real time PCR, while miRNAs showing the expression differences in relation to clinical variables were further analyzed in 52 PCa and 12 noncancerous prostate tissues (NPT) on TaqMan Low Density Arrays (TLDA). ResultsAnalysis of miRNA expression in prostate tissue linked miR-95 to aggressive form of PCa. This miRNA was up-regulated in high grade (P=0.041), the TMPRSS2-ERG fusion-positive tumors (P=0.026), and in patients with subsequently developed biochemical recurrence (BCR; P=0.054) after radical prostatectomy. MiRNAs highly expressed in PCa tissues were also detectable in urine from PCa patients. Moreover, the urinary levels of miR-21 had significant discriminatory power (P=0.010) to separate PCa patients from BPH, while the combined analysis of urinary miR-19a and miR-19b was prognostic for BCR. In PCa, the diagnostic potential of urinary miRNA panel (miR-21, miR-19a, and miR-19b) was higher than that of the PSA test (AUC=0.738 vs. AUC=0.514). ConclusionsMeasurement of urinary levels of PCa-specific miRNAs could assist in more specific detection of PCa and prediction of BCR.

Strong [68Ga]PSMA-HBED-CC accumulation in non-cancerous prostate tissue surrounding a PSMA-negative prostate carcinoma recurrence

Strong [68Ga]PSMA-HBED-CC accumulation in non-cancerous prostate tissue surrounding a PSMA-negative prostate carcinoma recurrence -

Differentiating cancerous tissues from noncancerous tissues using single-fiber reflectance spectroscopy with different fiber diameters.

Elastic light-scattering spectra acquired with single-fiber optical probes with diameters of 100, 200, 400, 600, 800, 1000, 1200, and 1500 μm were used to differentiate cancerous from noncancerous prostate tissues. The spectra were acquired ex vivo on 24 excised prostate tissue samples collected from four patients. For each probe, the spectra and histopathology results were compared in order to investigate the correlation between the core diameters of the single-fiber optical probe and successful differentiation between cancerous and noncancerous prostate tissues. The spectra acquired using probes with a fiber core diameter of 400 μm or smaller successfully differentiated cancerous from noncancerous prostate tissues. Next, the spectra were acquired from monosized polystyrene microspheres with a diameter of 5.00±0.01 μm to investigate the correlation between the core diameters of the probes and the Mie oscillations on the spectra. Monte Carlo simulations of the light distribution of the tissue phantoms were run to interrogate whether the light detected by the probes with different fiber core diameters was in the ballistic or diffusive regime. If the single-fiber optical probes detect light in the ballistic regime, the spectra can be used to differentiate between cancerous and noncancerous tissues.

Prognostic value of ZFP36 and SOCS3 expressions in human prostate cancer.

ZFP36 ring finger protein (ZFP36) and the suppressor of cytokine signaling 3 (SOCS3) have been reported to, respectively, regulate NF-κB and STAT3 signaling pathways. To better understand the correlation of NF-κB and STAT3 negative regulates pathway, we have investigated the involvement of ZFP36 and SOCS3 expressions in human prostate cancer (PCa). In the present study, paired patient tissue microarrays were analyzed by immunohistochemistry, and the ZFP36 protein expression was quantitated as immunoreactive scores in patients with PCa. Associations between ZFP36/SOCS3 expression and various clinicopathological features and prognosis of PCa patients were statistically analyzed based on the Taylor database. Then, the functions of ZFP36 and SOCS3 in cancerous inflammation were determined using qPCR and immunohistochemistry in vitro and in vivo. ZFP36 protein expression in PCa tissues was significantly lower than those in non-cancerous prostate tissues (P<0.05). In mRNA level, ZFP36 and SOCS3 had a close correlation with each other (P<0.01, Pearson r=0.848), and its upregulation was both significantly associated with low Gleason score (P<0.001 and P<0.001, respectively), negative metastasis (P<0.001 and P<0.001, respectively), favorable overall survival (P<0.001 and P<0.05, respectively), and negative biochemical recurrence (P<0.001 and P<0.001, respectively). Functionally, LPS treatment could lead to the overexpression of ZFP36 and SOCS3 in vitro and vivo. Our data offer the convincing evidence for the first time that the aberrant expressions of ZFP36 and SOCS3 may be involved into the progression and patients' prognosis of PCa, implying their potentials as candidate markers of this cancer.

Frequent down-regulation of ABC transporter genes in prostate cancer.

BackgroundATP-binding cassette (ABC) transporters are transmembrane proteins responsible for the efflux of a wide variety of substrates, including steroid metabolites, through the cellular membranes. For better characterization of the role of ABC transporters in prostate cancer (PCa) development, the profile of ABC transporter gene expression was analyzed in PCa and noncancerous prostate tissues (NPT).MethodsTaqMan Low Density Array (TLDA) human ABC transporter plates were used for the gene expression profiling in 10 PCa and 6 NPT specimens. ABCB1 transcript level was evaluated in a larger set of PCa cases (N = 78) and NPT (N = 15) by real-time PCR, the same PCa cases were assessed for the gene promoter hypermethylation by methylation-specific PCR.ResultsExpression of eight ABC transporter genes (ABCA8, ABCB1, ABCC6, ABCC9, ABCC10, ABCD2, ABCG2, and ABCG4) was significantly down-regulated in PCa as compared to NPT, and only two genes (ABCC4 and ABCG1) were up-regulated. Down-regulation of ABC transporter genes was prevalent in the TMPRSS2-ERG-negative cases.A detailed analysis of ABCB1 expression confirmed TLDA results: a reduced level of the transcript was identified in PCa in comparison to NPT (p = 0.048). Moreover, the TMPRSS2-ERG-negative PCa cases showed significantly lower expression of ABCB1 in comparison to NPT (p = 0.003) or the fusion-positive tumors (p = 0.002). Promoter methylation of ABCB1 predominantly occurred in PCa and was rarely detected in NPT (p < 0.001).ConclusionsThe study suggests frequent down-regulation of the ABC transporter genes in PCa, especially in the TMPRSS2-ERG-negative tumors.Electronic supplementary materialThe online version of this article (doi:10.1186/s12885-015-1689-8) contains supplementary material, which is available to authorized users.

Abstract 1483: Lipid oxidation via CPT1 as a target for prostate cancer imaging and therapy

Abstract Introduction: Prostate cancer (PCa) is the most common cancer in males and is currently treated medically with androgen deprivation therapy. However, resistance to androgen receptor (AR) targeted therapy develops in almost all patients over time. Simultaneously targeting multiples pathways may prevent the development of this resistance. Recent studies suggest PCa relies on lipid fuel over glycolysis. Blocking the ability of PCa to use lipids inhibits its growth and leads to apoptosis but enhances glucose uptake initially, potentially enhancing glucose-based FDG-PET (18F-dexyglucose-Positron Emission Tomography) imaging of PCa tumors. Experimental approach: To address the role of lipid metabolism in PCa we have used etomoxir, a clinically utilized drug that blocks lipid oxidation by inhibiting carnitine palmitoyltransferase (CPT1) in the mitochondria. Enzalutamide is a clinically available anti-androgen, which was used by itself or in combination with etomoxir. The gene/drug interaction was studied in LNCaP cells with decreased expression of CPT1A (via shRNA). PET-FDG of mouse xenografts were used to evaluated the glycolytic switch induced by systemic etomoxir treatment in 24 hours and the therapeutic effect over time. Results: Treatment with etomoxir alone significantly decreased cell viability and AR content, including ARv7 variant. Combinatorial treatment with enzalutamide synergistically enhanced this effect on viability. CPT1A Knockdown clones were also more sensitive to enzalutamide (2 fold, p&amp;lt;0.001) compared to control clones, and this effect was associated with reduced AR expression. Systemic treatment with etomoxir alone in nude mice resulted in decreased xenograft growth over 21 days, underscoring the therapeutic potential of blocking lipid catabolism to decrease PCa tumor growth. Interestingly, FDG uptake by VCaP xenografts was increased with systemic etomoxir in 24 hours (∼1.5 fold, P&amp;lt;0.05), enhancing the visualization of the tumors in the PET scans. FDG uptake in the mouse non-cancerous prostate tissue was negligible with etomoxir. Conclusions: Safely blocking lipid oxidation in PCa results in decreased viability with temporarily increased glucose uptake, due to a flare of glucose uptake to compensate for the fat oxidation blockade. Validation in human PCa patients with localized disease is needed to confirm these preclinical studies. Additionally, the decreased viability over time suggests that lipid metabolism is needed to maintain AR expression and combination of fat burning inhibitors and enzalutamide may offer novel approach to anti-AR resistance in PCa. Citation Format: Isabel R. Schlaepfer, Maren Salzmann-Sullivan, Lih-Jen Su, L.Michael Glode, Thomas Flaig. Lipid oxidation via CPT1 as a target for prostate cancer imaging and therapy. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1483. doi:10.1158/1538-7445.AM2015-1483

Prostate carcinoma: Accuracy of diagnosis and differentiation with Dynamic Contrast-Enhanced MRI and Diffusion Weighted Imaging

BackgroundDiffusion weighted image (DWI) and dynamic contrast enhanced MR imaging (DCE-MRI) provide excellent parameters that are useful for differentiating cancer from normal tissue in prostatic cancer patients. PurposeTo define the diagnostic value of diffusion weighted image (DWI) and dynamic contrast enhanced MR imaging (DCE-MRI) and determine whether the combination of the two techniques provides higher diagnostic accuracy for prostate cancer than each technique alone. Material and methods30 patients suggested to have prostate cancer based on high PSA value underwent MRI examination including axial T2-WI, diffusion weighted image (DWI), apparent diffusion coefficient (ADC) and dynamic contrast enhanced MRI (DCE-MRI). The final diagnosis was confirmed by histopathological study of the TRUS-guided biopsies. ResultsThe sensitivity of DCE-MRI, ADC at 1.2 and ADC at 1.4 in detection of prostatic carcinoma was 100%, 84.6% and 100% respectively (P=0.000). The highest validity for cancer prostate is DCE-MRI (Kappa=0.93) followed by ADC at 1.4 (Kappa=0.86) then ADC at 1.2 (Kappa=0.79). ConclusionsDCE-MRI and DWI have high sensitivity to differentiate cancerous from non-cancerous prostatic tissue, and the combination of both techniques increase the diagnostic accuracy of prostatic cancer than each one alone.

Haralick texture analysis of prostate MRI: utility for differentiating non-cancerous prostate from prostate cancer and differentiating prostate cancers with different Gleason scores.

To investigate Haralick texture analysis of prostate MRI for cancer detection and differentiating Gleason scores (GS). One hundred and forty-seven patients underwent T2- weighted (T2WI) and diffusion-weighted prostate MRI. Cancers ≥0.5ml and non-cancerous peripheral (PZ) and transition (TZ) zone tissue were identified on T2WI and apparent diffusion coefficient (ADC) maps, using whole-mount pathology as reference. Texture features (Energy, Entropy, Correlation, Homogeneity, Inertia) were extracted and analysed using generalized estimating equations. PZ cancers (n = 143) showed higher Entropy and Inertia and lower Energy, Correlation and Homogeneity compared to non-cancerous tissue on T2WI and ADC maps (p-values: <.0001-0.008). In TZ cancers (n = 43) we observed significant differences for all five texture features on the ADC map (all p-values: <.0001) and for Correlation (p = 0.041) and Inertia (p = 0.001) on T2WI. On ADC maps, GS was associated with higher Entropy (GS 6 vs. 7: p = 0.0225; 6 vs. >7: p = 0.0069) and lower Energy (GS 6 vs. 7: p = 0.0116, 6 vs. >7: p = 0.0039). ADC map Energy (p = 0.0102) and Entropy (p = 0.0019) were significantly different in GS ≤3 + 4 versus ≥4 + 3 cancers; ADC map Entropy remained significant after controlling for the median ADC (p = 0.0291). Several Haralick-based texture features appear useful for prostate cancer detection and GS assessment. • Several Haralick texture features may differentiate non-cancerous and cancerous prostate tissue. • Tumour Energy and Entropy on ADC maps correlate with Gleason score. • T2w-image-derived texture features are not associated with the Gleason score.

Selenium, nickel, and calcium levels in cancerous and non-cancerous prostate tissue samples and their relation with some parameters.

In the present study, tissue samples of patients with cancerous and non-cancerous prostate were analyzed for their Se, Ni, and Ca contents. Possible relationship between Se, Ni, and Ca concentrations and some parameters including preoperative prostate-specific antigen (PSA) levels, histopathological neurovascular invasion, extra-capsular extension, seminal vesicle invasion, positive surgical margins, PSA relapse after radical prostatectomy, and total Gleason scores were obtained. Inductively coupled plasma (ICP) optical emission spectrometry and ICP-mass spectrometry instruments were used for the determination of analytes interested. All the system parameters in digestion and measurement steps were optimized to obtain efficient digestion and sensitive measurements. There was no statistically meaningful difference observed in the concentration of selenium in cancerous and benign prostatic tissues (p = 0.347) while nickel levels in cancerous tissues were observed as significantly lower than benign tissues (p < 0.001). In addition, calcium concentration in cancerous tissue samples were found to be statistically lower than those in benign tissues (p < 0.001) with mean values of 657 and 1,431mg/kg, respectively.

Aberrant hypomethylation-mediated CD147 overexpression promotes aggressive tumor progression in human prostate cancer.

Our previous study revealed the potential role of CD147 in human prostate cancer (PCa). Here, we investigated the CD147 promoter methylation status and the correlation with tumorigenicity in human PCa. CD147 mRNA and protein expression levels were both significantly higher in the 4 PCa cell lines, than in the 2 non-tumorigenic benign human prostatic epithelial cell lines (all P<0.01). We showed hypomethylation of promoter regions of CD147 in PCa cell lines with significant CD147 expression as compared to non-tumorigenic benign human prostatic epithelial cell lines slowly expressing CD147. Additionally, the treatment of methylated cell lines with 5-aza-2'-deoxycytidine increased CD147 expression significantly in low-expressing cell lines and also activated the expression of matrix metalloproteinase (MMP)-2, which may be one of the most important downstream targets of CD147. Furthermore, PCa tissues displayed decreased DNA methylation in the promoter region of CD147 compared to the corresponding non-cancerous prostate tissues, and methylation intensity correlated inversely with the CD147 mRNA levels. There was a significant negative correlation between CD147 mRNA levels and the number of methylated sites in PCa tissues (r=-0.467, P<0.01). In conclusion, our data offer convincing evidence for the first time that the DNA promoter hypomethylation of CD147 may be one of the regulatory mechanisms involved in the cancer-related overexpression of CD147 and may play a crucial role in the tumorigenesis of PCa.

Enhanced expression of centromere protein F predicts clinical progression and prognosis in patients with prostate cancer.

Centromere protein F (CENPF) is a protein associated with the centromere-kinetochore complex and chromosomal segregation during mitosis. Previous studies have demonstrated that the upregulation of CENPF may be used as a proliferation marker of malignant cell growth in tumors. The overexpression of CENPF has also been reported to be associated with a poor prognosis in human cancers. However, the clinical significance of CENPF in prostate cancer (PCa) has not yet been fully elucidated. Thus, the aim of the present study was to determine the association of CENPF with tumor progression and prognosis in patients with PCa. The expression of CENPF at the protein level in human PCa and non-cancerous prostate tissues was detected by immunohistochemical analysis, which was further validated using a microarray-based dataset (NCBI GEO accession no: GSE21032) at the mRNA level. Subsequently, the association of CENPF expression with the clinicopathological characteristics of the patients with PCa was statistically analyzed. Immunohistochemistry and dataset analysis revealed that CENPF expression was significantly increased in the PCa tissues compared with the non-cancerous prostate tissues [immunoreactivity score (IRS): PCa, 177.98 ± 94.096 vs. benign, 121.30 ± 89.596, P < 0.001; mRNA expression in the dataset: PCa, 5.67 ± 0.47 vs. benign, 5.40 ± 0.11; P < 0.001]. Additionally, as revealed by the dataset, the upregulation of CENPF mRNA expression in the PCa tissues significantly correlated with a higher Gleason score (GS, P = 0.005), an advanced pathological stage (P = 0.008), the presence of metastasis (P < 0.001), a shorter overall survival (P=0.003) and prostate-specific antigen (PSA) failure (P < 0.001). Furthermore, both univariate and multivariate analyses revealed that the upregulation of CENPF was an independent predictor of poor biochemical recurrence (BCR)-free survival (P < 0.001 and P = 0.012, respectively). Our data suggest that the increased expression of CENPF plays an important role in the progression of PCa. More importantly, the increased expression of CENPF may efficiently predict poor BCR-free survival in patients with PCa.

Downregulation of EphA5 by promoter methylation in human prostate cancer.

BackgroundEphA5 is a member of the Eph/ephrin family and plays a critical role in the regulation of carcinogenesis. A significant reduction of EphA5 transcripts in high-grade prostate cancer tissue was shown using a transcriptomic analysis, compared to the low-grade prostate cancer tissue. As less is known about the mechanism of EphA5 downregulation and the function of EphA5, here we investigated the expression and an epigenetic change of EphA5 in prostate cancer and determined if these findings were correlated with clinicopathologic characteristics of prostate cancer.MethodsSeven prostate cell lines (RWPE-1, LNCap, LNCap-LN3, CWR22rv-1, PC-3, PC-3M-LN4, and DU145), thirty-nine BPH, twenty-two primary prostate carcinomas, twenty-three paired noncancerous and cancerous prostate tissues were examined via qRT-PCR, methylation-specific PCR, bisulfite sequencing, immunohistochemistry and western blotting. The role of EphA5 in prostate cancer cell migration and invasion was examined by wound healing and transwell assay.ResultsDownregulation or loss of EphA5 mRNA or protein expression was detected in 28 of 45 (62.2%) prostate carcinomas, 2 of 39 (5.1%) hyperplasias, and all 6 prostate cancer cell lines. Methylation of the EphA5 promoter region was present in 32 of 45 (71.1%) carcinoma samples, 3 of 39 (7.7%) hyperplasias, and the 6 prostate cancer cell lines. Among 23 paired prostate carcinoma tissues, 16 tumor samples exhibited the hypermethylation of EphA5, and 15 of these 16 specimens (93.8%) shown the downregulation of EphA5 expression than that of their respectively matched noncancerous samples. Immunostaining analysis demonstrated that the EphA5 protein was absent or down-regulated in 10 of 13 (76.9%) available carcinoma samples, and 8 of these 10 samples (80.0%) exhibited hypermethylation. The frequency of EphA5 methylation was higher in cancer patients with an elevated Gleason score or T3-T4 staging. Following the treatment of 6 prostate cancer cell lines with 5-aza-2′-deoxycytidine, the levels of EphA5 mRNA were significantly increased. Prostate cancer cells invasion and migration were significantly suppressed by ectopic expression of EphA5 in vitro.ConclusionOur study provides evidence that EphA5 is a potential target for epigenetic silencing in primary prostate cancer and is a potentially valuable prognosis predictor and thereapeutic marker for prostate cancer.Electronic supplementary materialThe online version of this article (doi:10.1186/s12885-015-1025-3) contains supplementary material, which is available to authorized users.

The epigenetics of prostate cancer diagnosis and prognosis: update on clinical applications.

There is a major deficit in our ability to detect and predict the clinical behavior of prostate cancer (PCa). Epigenetic changes are associated with PCa development and progression. This review will focus on recent results in the clinical application of diagnostic and prognostic epigenetic markers. The development of high throughput technology has seen an enormous increase in the discovery of new markers that encompass epigenetic changes including those in DNA methylation and histone modifications. Application of these findings to urine and other biofluids, but also cancer and noncancerous prostate tissue, has resulted in new biomarkers. There has been a recent commercial development of a DNA methylation-based assay for identifying PCa risk from normal biopsy tissue. Other biomarkers are currently in the validation phase and encompass combinations of multiple genes. Epigenetic changes improve the specificity and sensitivity of PCa diagnosis and have the potential to help determine clinical prognosis. Additional studies will not only provide new and better biomarker candidates, but also have the potential to inform new therapeutic strategies given the reversibility of these processes.

Epigenetic regulation of EFEMP1 in prostate cancer: biological relevance and clinical potential.

Epigenetic alterations are common in prostate cancer (PCa) and seem to contribute decisively to its initiation and progression. Moreover, aberrant promoter methylation is a promising biomarker for non-invasive screening. Herein, we sought to characterize EFEMP1 as biomarker for PCa, unveiling its biological relevance in prostate carcinogenesis. Microarray analyses of treated PCa cell lines and primary tissues enabled the selection of differentially methylated genes, among which EFEMP1 was further validated by MSP and bisulfite sequencing. Assessment of biomarker performance was accomplished by qMSP. Expression analysis of EFEMP1 and characterization of histone marks were performed in tissue samples and cancer cell lines to determine the impact of epigenetic mechanisms on EFEMP1 transcriptional regulation. Phenotypic assays, using transfected cell lines, permitted the evaluation of EFEMP1’s role in PCa development. EFEMP1 methylation assay discriminated PCa from normal prostate tissue (NPT; P < 0.001, Kruskall–Wallis test) and renal and bladder cancers (96% sensitivity and 98% specificity). EFEMP1 transcription levels inversely correlated with promoter methylation and histone deacetylation, suggesting that both epigenetic mechanisms are involved in gene regulation. Phenotypic assays showed that EFEMP1 de novo expression reduces malignant phenotype of PCa cells. EFEMP1 promoter methylation is prevalent in PCa and accurately discriminates PCa from non-cancerous prostate tissues and other urological neoplasms. This epigenetic alteration occurs early in prostate carcinogenesis and, in association with histone deacetylation, progressively leads to gene down-regulation, fostering cell proliferation, invasion and evasion of apoptosis.