Noncancerous Prostate Research Articles

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.

Discovery of Novel N-alkyl 4-anilinofuro[2,3-b]quinoline Derivatives (CIL-102 Derivatives) Against Castration-resistant Human Prostate Cancers.

A number of N-alkylated 4-anilinofuro[2,3-b]quinoline derivatives were synthesized and evaluated in vitro against PC-3, A549, and MCF-7 cancer cells and M-10 normal human mammary epithelial cells. The known antimitotic CIL-102 was moderately active against the growth of PC-3 prostate cancer cells with an IC50 value of 2.69 μM while it was more potent against the growth of A549, MCF-7 and M-10 cells with IC50 values of 0.61, 0.31 and 0.95 μM, respectively. However, the cytotoxic profiles of its N-alkylated derivatives, 6a - 6c, were reversed and strongly inhibited PC-3 cell growth with IC50 values of less than 1.0 μM but only weakly against the growth of A549, MCF-7 and M-10 cells. These results indicated that N-alkylation of CIL-102 increased not only selectivity but also the antiproliferative potency against PC-3 cell growth. Among these derivatives synthesized, N-(4-acetylphenyl)-N-(furo[2,3-b]quinolin- 4-yl)methylamine (6a) and its N-ethyl counterpart 6b are the two most active CIL-102 derivatives against PC-3 cell growth with IC50 value of 0.22 and 0.20 μM, respectively. Compound 6a is less cytotoxic to normal human M-10 cells than 6b and therefore was selected for further mechanism studies. The flow cytometry studies clearly indicated that compound 6a induced cell accumulation in G2/M phase in a dose-dependent manner after 24 h-treatment. While the proliferation of LNCaP C-81 prostate cancer cells was also strongly suppressed by compound 6a; compound 11a exhibited better selective activity toward LNCaP C-81 prostate cancer cells over RWPE-1 non-cancerous prostate epithelia. Thus, this group of compounds has a potential of serving as therapeutic agents toward advanced castration-resistant prostate cancers.

Rapid identification by surface-enhanced Raman spectroscopy of cancer cells at low concentrations flowing in a microfluidic channel.

Reliable identification and collection of cells from bodily fluids is of growing interest for monitoring patient response to therapy and for early detection of disease or its recurrence. We describe a detection platform that combines microfluidics with surface-enhanced Raman spectroscopy (SERS) for the identification of individual mammalian cells continuously flowing in a microfluidics channel. A mixture of cancerous and noncancerous prostate cells was incubated with SERS biotags (SBTs) developed and synthesized by us, then injected into a flow-focused microfluidic channel, which forces the cells into a single file. The spectrally rich SBTs are based on a silver nanoparticle dimer core labeled with a Raman-active small reporter molecule paired with an affinity biomolecule, providing a unique barcode whose presence in a composite SERS spectrum can be deconvoluted. Individual cancer cells passing through the focused laser beam were correctly identified among a proportionally larger number of other cells by their Raman signatures. We examine two deconvolution strategies: principal component analysis and classical least-squares. The deconvolution strategies are used to unmix the overall spectrum to determine the relative contributions between two SBT barcodes, where one SBT barcode indicates neuropilin-1 overexpression, while a second SBT barcode is more universal and indicates unspecific binding to a cell's membrane. Highly reliable results were obtained for all of the cell mixture ratios tested, the lowest being 1 in 100 cells.

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.

Association of Arg462Gln Polymorphism in RNASEL Gene With the Risk of Prostate CancerAmong Iranian Population

In the July issue of “Gene, Cell and Tissue”, R462Q Mutation in Prostate Cancer Specimens 1 investigated the effect of Arg462Gln polymorphism in sporadic prostate cancer patients among Iranian population. The study samples comprised of formalin fixed paraffin embedded specimen obtained from 51 histopathologically confirmed specimens from patients with prostate cancer and 70 from control individuals with non-cancerous prostate (prostatitis, hyperplasia). RNASEL Arg462Gln or G1385A polymorphism analysis performed using ARMS (Amplification Refractory Mutation System) PCR with allele specific primers were used to detect single-base substitution. This was followed by the association analysis between RNASEL genotype and prostate cancer. The authors could not find any significant association between the polymorphism and risk of disease. Few years back a worldwide epidemiological survey on prostate cancer revealed that it is the third leading causes of death in developed countries such as United States and emphasized that it is becoming a growing health concern in the developing nations as well 2. Like any other complex neoplastic disorder both genetic and non genetic factors interact in its development and progression 3. Age, ethnic background and family history are the three main epidemiological risk factors for this disease out of which family history is the strongest contributor. Based on family history, prostate cancer can be classified into sporadic, familial and hereditary. Hereditary predispositions are quite rare and contribute to less than 5% of the cases while familial cases account for 10-20% of cases. The rest are sporadic cases with typically only one person in their family who were diagnosed with the disease 4. Numerous studies have been conducted to identify the prostate cancer susceptibility genes using linkage analysis. Smith et al. identified the first susceptibility locus, designated as HPC1, which mapped to the long arm of chromosome 1 (1q24-25) (5), few years later, Carpten et al. reported RNASEL gene as one of the candidate for HPC1 (6). RNASEL is an endonuclease involving in apoptotic and antiviral activities of interferons. Along with truncating mutations in this gene, several missense variants were reported by Rokman et al. by screening the entire coding sequence of RNASEL using Single-strand conformation polymorphism (SSCP) (7). The Arg462Gln variant has a significant role in hereditary prostate cancer as the variant has three times less enzymatic activity compared to the wild genotype (8). They also reported that heterozygous individuals had double the risk of prostate cancer compared to the noncarrier cases with hereditary prostate cancer, but at the same time various studies did not find any association between sporadic prostate cancer and this variation in Caucasian and African American population (8, 9). The statistical analysis has been limited to unadjusted risk calculation. The risk calculation after adjustment to the age and clinical parameters would be a better approach. The control DNA was taken from hyperplastic prostate tissue so this tissue may not represent as a proper control sample. It is better to use DNA samples obtained from healthy individuals as the healthy control. Moreover the sample size is very small for any association study thus; a larger sample size is certainly warranted in future. Sometimes, ARMS PCR may produce incorrect genotypes, especially in homozygotes, so, it is better to recheck the genotypes by alternate sequencing methods. The authors did not find any association between Arg462Gln polymorphism and the risk of sporadic prostate cancer. Despite the limitations, this study is important as it may be first of its kind among Iranian population.

Aerobic glycolysis, motility, and cytoskeletal remodeling

Cancer cell motility and cytoskeletal remodeling are ubiquitous processes essential in cancer progression to metastasis. The role of metabolism in driving motility processes and cytoskeletal rearrangements is not fully understood, but abnormal usage of cellular energetics is a well-documented hallmark of cancer.1 Shiraishi and colleagues now provide evidence that energy utilized for cancer cell motility and cytoskeletal rearrangement processes is derived primarily from aerobic glycolysis and not mitochondrial oxidative phosphorylation, indicative of a deep metabolic compartmentalization program within cancer cells2 (Fig. 1). Figure 1. Energy for cancer cell movement is derived from glycolysis. The authors demonstrate that more aggressive mesenchymal prostate cancer cells (PC3-EMT) exhibit an increased level of basal aerobic glycolysis relative to less aggressive epithelial prostate cancer cells (PC3-Epi) and non-cancerous human prostate epithelial cells (PrECs). These findings are consistent with the Warburg effect, which describes a high rate of aerobic glycolysis as a major consequence of tumorigenesis.3 Mitochondrial respiration is unchanged between the aggressive and less aggressive prostate cancer cells but provides the bulk of cellular energy in both groups. This finding highlights a widely held misconception about the Warburg Effect; despite the increased rate of aerobic glycolysis in tumor cells, mitochondrial respiration still provides the majority of cellular ATP. In addition, a higher glycolytic capacity in PC3-EMT cells (maximal rate of glycolysis) relative to PC3-Epi and PrECs was observed. Complementary studies were executed with the breast cancer cell line MDA-MB-231 (mesenchymal) and MDA-MB-231-EPI (overexpressing the transcription factors OVOL1 and OVOL2 which drive a mesenchymal to epithelial transition). The stable expression of OVOL1 and OVOL2 led to a decrease in proton production rate (PPR), a surrogate measurement for aerobic glycolysis, in MDA-MB-231 cells. Consistent with previous findings, these studies highlight the metabolic shift toward aerobic glycolysis in cells that display an aggressive phenotype.4 Given the importance of actin polymerization and subsequent turnover during cellular motility and cellular invasion in cancer progression,5 cytoskeletal (CSK) rearrangement was measured by measuring contractile moment, cellular movement, and focal adhesion formation. PC3-EMT cells display a greater net contractile moment and a greater capacity to remodel their cytoskeleton than PC3-Epi cells. By tracking cellular displacement over time, PC3-EMT cells displayed greater motility relative to PC3-Epi cells. Cancer cell motility in both cancer cell lines is attenuated upon addition of 2-deoxy-D-Glucose (2-DG), a potent inhibitor of aerobic glycolysis, but not upon addition of oligomycin A, an inhibitor of mitochondrial respiration (Fig. 1). Focal adhesion formation and cellular contractile moment are also dramatically decreased upon addition of 2-DG but not oligomycin A. These findings are surprising given that actin is an ATPase and that mitochondrial respiration provides the majority of cellular ATP for these cells.2,6 Taken together, these findings indicate that aerobic glycolysis but not mitochondrial respiration is necessary for cellular movement (Fig. 1). Additionally, these studies underscore the importance of aerobic glycolysis in CSK rearrangement and focal adhesion formation. This study demonstrates a direct link between aerobic glycolysis and cellular movement consistent with previous studies that describe glycolytic enzyme co-localization at sites of active actin turnover.7 Surprisingly, the source of fuel for motility appears to be more important than the amount of energy provided by a given fuel type (Fig. 1) indicative of cellular compartmentalization of metabolic flux. These findings suggest that targeting aerobic glycolysis therapeutically could curb cancer cell motility and subsequent metastasis.

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.

Reciprocal regulation of PCGEM1 and miR-145 promote proliferation of LNCaP prostate cancer cells.

Prostate cancer gene expression marker 1 (PCGEM1) is a long non-coding RNA (lncRNA) overexpressed in prostate cancer (PCa) cells that promotes PCa initiation and progression, and protects against chemotherapy-induced apoptosis. The microRNA miR-145 functions as a tumor suppressor in PCa. We speculate that reciprocal regulation of PCGEM1 and miR-145 promote proliferation of LNCaP prostate cancer cells. To test this hypothesis, the interaction between PCGEM1 and miR-145 was examined using a luciferase reporter assay. Expression levels were selectively altered in LNCaP cells and noncancerous RWPE-1 prostate cells by transfection of miR-145 or small interfering RNA sequences against (siRNA) PCGEM1. Relative expression levels were detected by RT-PCR, tumor cell growth and early apoptosis by the MTT assay and flow cytometry, respectively, and tumor cell migration and invasion properties by transwell assays. The effect of siRNA PCGEM1 and miR-145 transfection on prostate cancer growth in vivo was examined in the (nu/nu) mouse model. PCGEM1 and miR-145 exhibited reciprocal regulation; downregulation of PCGEM1 expression in LNCaP cells increased expression of miR-145, while overexpression of miR-145 decreased PCGEM1 expression. Transfection of the miR-145 expression vector and siRNA PCGEM1 inhibited tumor cell proliferation, migration, and invasion, and induced early apoptosis both in vitro. In contrast, there was no effect on RWPE-1 cells. We demonstrate a reciprocal negative control relationship between PCGEM1 and miR-145 that regulates both LNCaP cell proliferation and nu/nu PCa tumor growth. The results also identify PCGEM1 and associated regulators as possible targets for PCa therapy.

EpCAM is overexpressed in local and metastatic prostate cancer, suppressed by chemotherapy and modulated by MET-associated miRNA-200c/205

Background:Expression of epithelial cell adhesion molecule (EpCAM) is deregulated in epithelial malignancies. Beside its role in cell adhesion, EpCAM acts as signalling molecule with tumour-promoting functions. Thus, EpCAM is part of the molecular network of oncogenic receptors and considered an interesting therapeutic target.Methods:Here, we thoroughly characterised EpCAM expression on mRNA and protein level in comprehensive tissue studies including non-cancerous prostate specimens, primary tumours of different grades and stages, metastatic lesions, and therapy-treated tumour specimens, as well as in prostate cancer cell lines.Results:Epithelial cell adhesion molecule was overexpressed at mRNA and at protein level in prostate cancer tissues and cell lines. Altered EpCAM expression was an early event in prostate carcinogenesis with an upregulation in low-grade cancers and further induction in high-grade tumours and metastatic lesions. Interestingly, EpCAM was repressed upon induction of epithelial-to-mesenchymal transition (EMT) following chemotherapeutic treatment with docetaxel. Oppositely, re-induction of the epithelial phenotype through miRNAs miR-200c and miR-205, two inducers of mesenchymal-to-epithelial transition (MET), led to re-induction of EpCAM in chemoresistant cells. Furthermore, we prove that EpCAM cleavage, the first step of EpCAM signalling takes place in prostate cancer cells but in contrast to other cancer entities, EpCAM has no measurable impact on the proliferative behaviour of prostate cells, in vitro.Conclusions:In conclusion, our data confirm that EpCAM overexpression is an early event during prostate cancer progression. Epithelial cell adhesion molecule displays a dynamic, heterogeneous expression and associates with epithelial cells rather than mesenchymal, chemoresistant cells along with processes of EMT and MET.

Prognostic Value of RASSF1 Promoter Methylation in Prostate Cancer

Patients with prostate cancer who have biochemical recurrence after curative therapy are at higher risk for distant metastasis and cancer specific death. Assessment of aberrant DNA methylation in urine might complement currently used clinical prognostic factors and serve as a noninvasive tool for early prediction of biochemical recurrence after radical prostatectomy. Promoter methylation of 7 genes was evaluated by methylation sensitive polymerase chain reaction in 149 prostate cancer tissues, 37 noncancerous prostate tissues and 17 benign prostatic hyperplasia samples. Quantitative polymerase chain reaction was used for DNA methylation analysis of the urine of 253 patients with prostate cancer and 32 with benign prostatic hyperplasia. In prostate cancer tissue the most frequently methylated genes were RASSF1, GSTP1 and RARB, which combined were positively identified in 85% ofcases. These genes were also methylated in the urine of 60% of patients withprostate cancer. RASSF1 was methylated in 45% of prostate cancer urine samples with methylation intensity significantly higher in prostate cancer thanin benign prostatic hyperplasia cases (p = 0.018). In a univariate model RASSF1 methylation and the total number of methylated genes in prostate cancer tissue were predictive of time to biochemical recurrence (p = 0.019 and 0.043, respectively). On multivariate analysis RASSF1 methylation together with pathological stage was the most significant predictor of biochemical recurrence in patients with Gleason score 6 tumors when analyzed in tissue and urine (p ≤0.001). Hypermethylation of RASSF1 in cancerous tissue and urine from patients with prostate cancer correlated with biochemical recurrence after radical prostatectomy. The prognostic potential of this biomarker deserves further investigation.

DNA methylation status is more reliable than gene expression at detecting cancer in prostate biopsy

Background:We analysed critically the potential usefulness of RNA- and DNA-based biomarkers in supporting conventional histological diagnostic tests for prostate carcinoma (PCa) detection.Methods:Microarray profiling of gene expression and DNA methylation was performed on 16 benign prostatic hyperplasia (BPH) and 32 cancerous and non-cancerous prostate samples extracted by radical prostatectomy. The predictive value of the selected biomarkers was validated by qPCR-based methods using tissue samples extracted from the 58 prostates and, separately, using 227 prostate core biopsies.Results:HOXC6, AMACR and PCA3 expression showed the best discrimination between PCa and BPH. All three genes were previously reported as the most promising mRNA-based markers for distinguishing cancerous lesions from benign prostate lesions; however, none were sufficiently sensitive and specific to meet the criteria for a PCa diagnostic biomarker. By contrast, DNA methylation levels of the APC, TACC2, RARB, DGKZ and HES5 promoter regions achieved high discriminating sensitivity and specificity, with area under the curve (AUCs) reaching 0.95−1.0. Only a small overlap was detected between the DNA methylation levels of PCa-positive and PCa-negative needle biopsies, with AUCs ranging between 0.854 and 0.899.Conclusions:DNA methylation-based biomarkers reflect the prostate malignancy and might be useful in supporting clinical decisions for suspected PCa following an initial negative prostate biopsy.

Design, synthesis and systematic evaluation of cytotoxic 3-heteroarylisoquinolinamines as topoisomerases inhibitors

A series of 3-heteroarylisoquinolinamines were designed, synthesized and evaluated for cytotoxicity, topoisomerases (topos) inhibitory activities and cell cycle inhibition. Several of the 3-heteroarylisoquinolines exhibited selective cytotoxicity against human ductal breast epithelial tumor (T47D) cells over non-cancerous human breast epithelial (MCF-10A) and human prostate cancer (DU145) cells. Most of the derivatives showed greater cytotoxicity in human colorectal adenocarcinoma (HCT-15) cells than camptothecin (CPT), etoposide and doxorubicin (DOX). Generally, 3-heteroarylisoquinolinamines displayed greater affinity for topo I than topo II. 3-Heteroarylisoquinolinamines with greater topo I inhibitory effect exhibited potent cytotoxicity. Piperazine-substituted derivative, 5b, with potent topo I and moderate topo II activities intercalated between DNA bases and interacted with topos through H-bonds at the DNA cleavage site of a docking model. Moreover, flow cytometry indicated that cytotoxic 3-heteroarylisoquinolinamines led to accumulation of human cervical (HeLa) cancer cells in the different phases of the cell cycle before apoptosis. Taken together, 3-heteroarylisoquinolinamines possessed potent cytotoxicity with topos and cell cycle inhibitory activities.

Prognostic value of matrix metalloprotease-1/protease-activated receptor-1 axis in patients with prostate cancer.

The aim of this study was to investigate the associations of matrix metalloprotease-1 (MMP-1) and its receptor protease-activated receptor-1 (PAR-1) coexpression with the clinicopathological characteristics and prognosis of patients with prostate cancer (PCa). Immunohistochemistry was performed to detect the expression changes of MMP-1 and PAR-1 proteins in 180 pairs of human PCa tissues and matched non-cancerous prostate tissues. Then, the associations of combined MMP-1 and PAR-1 expression with selected clinicopathological characteristics and patient prognosis were evaluated. Both MMP-1 and PAR-1 proteins were positively localized in cytoplasm of tumor cells in PCa tissues. Compared with non-cancerous prostate tissues, MMP-1 (PCa vs. Normal: 4.15 ± 1.28 vs. 2.37 ± 1.16, P < 0.001) and PAR-1 (PCa vs. Normal: 3.71 ± 1.21 vs. 1.55 ± 1.12, P < 0.001) protein expression were both significantly upregulated. More interestingly, the expression levels of MMP-1 in PCa tissues were positively correlated with those of PAR-1 significantly (Spearman correlation coefficient r = 0.88, P < 0.001). In addition, the coexpression of MMP-1 and PAR-1 (MMP-1-high/PAR-1-high) in PCa tissues was significantly associated with the higher Gleason score (P < 0.001), the presence of metastasis (P < 0.001) and the advanced pathological stage (P = 0.009). Furthermore, both univariate and multivariate analyses showed that MMP-1-high/PAR-1-high expression was an independent predictor for both unfavorable overall survival and biochemical recurrence-free survival. These findings confirmed for the first time that the upregulation of MMP-1 protein combined with the overexpression of PAR-1 protein may contribute to the malignant progression of PCa. More importantly, MMP-1/PAR-1 axis may be a negative prognostic factor for patients with PCa.

Confocal SERS mapping of glycan expression for the identification of cancerous cells.

Lectin-functionalized silver nanoparticles have been successfully designed for use as molecular imaging agents to investigate carbohydrate-lectin interactions at the surface of mammalian cells, using surface-enhanced Raman scattering (SERS). Carbohydrate-lectin interactions are key to many cellular processes and are responsible for controlling an array of cellular interactions. In this study, lectin-functionalized silver nanoparticles were used to detect the expression of carbohydrate species at the cellular interface. The carbohydrate-lectin interactions were demonstrated using three different lectin species for three distinct cell types. Due to the known difference between the expressions of glycans in cancerous versus noncancerous cells of the same origin, this approach has been expanded to study both cancerous and noncancerous prostate cells. This has been achieved via confocal SERS mapping of the expression of the key glycan, sialic acid, on the surface of each of these cell types. In achieving such discrimination, a novel method has been created by which glycan expression can be reproducibly monitored. Comparative studies were performed using both fluorescence and SERS. SERS provided an increased discrimination over fluorescence when analyzing cell subsets to discriminate between cancerous and noncancerous cells. The success of this method means that it could be used to complement the current gold standard histopathological techniques.

Incremental learning with SVM for multimodal classification of prostatic adenocarcinoma.

Robust detection of prostatic cancer is a challenge due to the multitude of variants and their representation in MR images. We propose a pattern recognition system with an incremental learning ensemble algorithm using support vector machines (SVM) tackling this problem employing multimodal MR images and a texture-based information strategy. The proposed system integrates anatomic, texture, and functional features. The data set was preprocessed using B-Spline interpolation, bias field correction and intensity standardization. First- and second-order angular independent statistical approaches and rotation invariant local phase quantization (RI-LPQ) were utilized to quantify texture information. An incremental learning ensemble SVM was implemented to suit working conditions in medical applications and to improve effectiveness and robustness of the system. The probability estimation of cancer structures was calculated using SVM and the corresponding optimization was carried out with a heuristic method together with a 3-fold cross-validation methodology. We achieved an average sensitivity of 0.844±0.068 and a specificity of 0.780±0.038, which yielded superior or similar performance to current state of the art using a total database of only 41 slices from twelve patients with histological confirmed information, including cancerous, unhealthy non-cancerous and healthy prostate tissue. Our results show the feasibility of an ensemble SVM being able to learn additional information from new data while preserving previously acquired knowledge and preventing unlearning. The use of texture descriptors provides more salient discriminative patterns than the functional information used. Furthermore, the system improves selection of information, efficiency and robustness of the classification. The generated probability map enables radiologists to have a lower variability in diagnosis, decrease false negative rates and reduce the time to recognize and delineate structures in the prostate.

Radiation-Induced Modulation of Costimulatory and Coinhibitory T-Cell Signaling Molecules on Human Prostate Carcinoma Cells Promotes Productive Antitumor Immune Interactions

We sought to determine if single-dose external beam radiation therapy (EBRT) could modulate the expression signature of T-cell costimulatory and coinhibitory molecules in human prostate cancer (PCa) cell lines in vitro. We investigated the functional impact of irradiated PCa cells with a modulated costimulatory profile on responder T-cell activity. We used three PCa cell lines (DU145, PC3, and LNCaP) and two epithelial cell lines from noncancerous prostate and lung tissue. After 72 hours of EBRT, surface expression of four immunostimulatory molecules (CD70, CD275/ICOSL, CD134L/OX40L, and CD137L/41BBL) and two immunosuppressive markers (CTLA-4/CD152 and PD-L1/CD274) were evaluated by flow cytometry. We evaluated the impact of several radiation doses and the longevity of modulated expression. We examined the functional impact of radiation-induced modulation of cancer cells by cytotoxic T cells (CTL) cytotoxicity and ELISPOT assay for interferon-gamma (IFN-γ) production. Last, we evaluated whether IFN-γ-induced PD-L1 expression could be reversed by EBRT. After 10 Gy EBRT, expression of OX40L and 41BBL increased in all three PCa cell lines; expression of CD70 and ICOSL increased in PC3 cells. Conversely, a decrease in PD-L1 expression in DU145 and PC3 cells was detectable up to 144 hours after EBRT. No PD-L1 was detected in LNCaP. Epithelial cells from normal prostate were not modulated by radiation. CTL cytolytic activity and IFN-γ production were enhanced by interaction with irradiated PCa cells. Finally, EBRT failed to prevent IFN-γ-induced upregulation of PD-L1. We demonstrate that a single dose of EBRT increased surface expression of costimulatory molecules and decreased the expression of coinhibitory molecules in human PCa cell lines. Changes in irradiated tumor cells led to functional enhancement of T-cell activity, despite EBRT failing to reduce IFN-γ-induced expression of PD-L1. These data suggest that combining radiotherapy with T-cell stimulating immunotherapy may be an attractive strategy for cancer treatment.