Normal Prostate Epithelium Research Articles

Phosphorylation of the oncogenic transcription factor ERG in prostate cells dissociates polycomb repressive complex 2, allowing target gene activation

In ∼50% of prostate cancers, chromosomal rearrangements cause the fusion of the promoter and 5'-UTR of the androgen-regulated TMPRSS2 (transmembrane protease, serine 2) gene to the open reading frame of ERG, encoding an ETS family transcription factor. This fusion results in expression of full-length or N-terminally truncated ERG protein in prostate epithelia. ERG is not expressed in normal prostate epithelia, but when expressed, it promotes tumorigenesis via altered gene expression, stimulating epithelial-mesenchymal transition, cellular migration/invasion, and transformation. However, limited knowledge about the molecular mechanisms of ERG function in prostate cells has hampered efforts to therapeutically target ERG. ERK-mediated phosphorylation of ERG is required for ERG functions in prostate cells, but the reason for this requirement is unknown. Here, we report a mechanism whereby ERK-mediated phosphorylation of ERG at one serine residue causes a conformational change that allows ERK phosphorylation at a second serine residue, Ser-96. We found that the Ser-96 phosphorylation resulted in dissociation of EZH2 and SUZ12, components of polycomb repressive complex 2 (PRC2), transcriptional activation of ERG target genes, and increased cell migration. Conversely, loss of ERG phosphorylation at Ser-96 resulted in recruitment of EZH2 across the ERG-cistrome and a genome-wide loss of ERG-mediated transcriptional activation and cell migration. In conclusion, our findings have identified critical molecular mechanisms involving ERK-mediated ERG activation that could be exploited for therapeutic intervention in ERG-positive prostate cancers.

SHISA2 enhances the aggressive phenotype in prostate cancer through the regulation of WNT5A expression.

The present study aimed at identifying novel molecular cancer drug targets and biomarkers by analyzing the gene expression profiles of high-grade prostate cancer (PC), using a cDNA microarray combined with laser microbeam microdissection. A number of genes were identified that were transactivated in high-grade PC. First, a novel molecular target and diagnostic biomarker, shisa family member 2 (SHISA2), was identified as an overexpressed gene in high-grade PC cells. The reverse transcription-semi-quantitative polymerase chain reaction and immunohistochemical analysis validated the overexpression of SHISA2 (295 amino acids in length), specifically in high-grade PC cells with Gleason scores of between 8 and 10, relative to normal prostate epithelium. Knockdown of SHISA2 expression by short interfering RNA resulted in the marked suppression of PC cell viability. By contrast, exogenous SHISA2 expression in transfected cells promoted PC cell proliferation, indicating its oncogenic effects. Notably, as a result of cDNA microarray analysis, protein Wnt-5a (WNT5A) was focused upon and the expression of WNT5A was identified to be downregulated in SHISA2-knockdown. Western blot analysis validated significant downregulation of WNT5A by SHISA2-knockdown and upregulation of WNT5A by SHISA2 overexpression. The results of the present study indicated that SHISA2 may affect WNT5A synthesis. Furthermore, the secreted SHISA2 protein was determined in the culture medium of PC cells. We hypothesize that SHISA2 is involved in the regulation of WNT5A and in the aggressiveness of PC via the Wnt signaling pathway through WNT5A. Furthermore, SHISA2 may be a molecular target for cancer drugs, and a useful diagnostic biomarker for the prognosis and therapeutic effect in cancer.

High-Level Glyoxalase 1 (GLO1) expression is linked to poor prognosis in prostate cancer.

Glyoxalase 1 (GLO1) is an enzyme involved in removal of toxic byproducts accumulating during glycolysis from the cell. GLO1 is up regulated in many cancer types but its role in prostate cancer is largely unknown. Here, we employed GLO1 immunohistochemistry on a tissue microarray including 11 152 tumors and an attached clinical and molecular database. Normal prostate epithelium was negative for GLO1, whereas 2059 (27.3%) of 7552 interpretable cancers showed cytoplasmic GLO1 staining, which was considered weak in 8.8%, moderate in 12.5%, and strong in 6.1% of tumors. Up regulation of GLO1 was significantly linked to high original Gleason grade, advanced pathological tumor stage and positive lymph node status (P < 0.0001 each). Comparison of GLO1 staining with several common genomic alterations of prostate cancers revealed a strong link between GLO1 up regulation and TMPRSS2:ERG fusion (P < 0.0001) and an ERG-independent association with PTEN deletion (P < 0.0001). GLO1 up regulation was strongly linked to early biochemical recurrence in univariate analysis (P < 0.0001) and predicted poor prognosis independent from most (except from nodal stage) established prognostic parameters in multivariate analysis (P ≤ 0.03). GLO1 upregulation is linked to aggressive prostate cancers characterized by ERG fusion and PTEN deletion. The strong and independent prognostic value makes it a promising candidate for routine diagnostic applications either alone or in combination with other markers.

MicroRNA-488 mediates the growth and glycolysis of human prostate cancer cells by targeting 6-phosphofructo-2-kinase 3 gene

Objective To investigate the effect of micrioRNA (miRNA, miR) -488 on glycolysis and proliferation of prostate cancer cells and the underlying mechanism. Methods Real-time quantitative polymerase chain reaction (Real-time PCR) was used to examine the expression of miR-488 in prostate cancer cells. Bioinformatics prediction and luciferase reporter gene assay were utilized for the identification of the target genes of miR-488. The expression levels of 6-phosphofructo-2-kinase 3 (PFKFB3) mRNA and protein were detected by Real-time PCR and Western blotting after the miR-488 mimic was transfected 24 h later. After miR-488 mimics was transfected, or co-transfected with PFKFB3 over-expression plasmid for 24 h, the capacity of proliferation and the glycolysis of prostate cancer cells (PC-3 and DU145) were determined by cell counting kit-8 (CCK-8), glucose uptake and lactate assay, respectively. Results Compared to the normal prostate epithelium cell RWPE-1, the expression of miR-488 in PC-3 and DU145 cell lines was 0.26±0.03 (P=0.031) and 0.19±0.04 (P=0.021), but there was no statistically significant difference in LNCaP and 22RV1 cells. The glucose uptake rate and the lactate secretion rate were 0.54±0.03 (P=0.042) and 0.52±0.01 (P=0.032), and 0.55±0.02 (P=0.037) and 0.61±0.17 (P=0.048) after up-regulating the expression of miR-488, which indicating the decline of glycolysis ability and the proliferation ability. Bioinformatics prediction and luciferase reporter gene assay showed that PFKFB3 was the target gene of miR-488. After the expression of miR-488 was up-regulated, the expression levels of PFKFB3 mRNA and protein were down-regulated. When miR-488 and PFKFB3 over-expression plasmids were co-transfected into the cells, the proliferation was elevated and the glucose uptake rate and lactate secretion rate were 0.79±0.12 and 0.82±0.11, and 0.77±0.07 (P=0.015) and 0.83±0.04 (P=0.026) respectively, indicating a higher glycolysis rate than the control. Conclusion MiR-488 can regulate the ability of proliferation and glycolsis of prostate cancer cells by targeting PFKFB3 gene. Key words: MicroRNA-488; 6-phosphofructo-2-kinase 3; Prostate cancer; Proliferation; Glycolysis

Stromal and epithelial transcriptional map of initiation progression and metastatic potential of human prostate cancer

While progression from normal prostatic epithelium to invasive cancer is driven by molecular alterations, tumor cells and cells in the cancer microenvironment are co-dependent and co-evolve. Few human studies to date have focused on stroma. Here, we performed gene expression profiling of laser capture microdissected normal non-neoplastic prostate epithelial tissue and compared it to non-transformed and neoplastic low-grade and high-grade prostate epithelial tissue from radical prostatectomies, each with its immediately surrounding stroma. Whereas benign epithelium in prostates with and without tumor were similar in gene expression space, stroma away from tumor was significantly different from that in prostates without cancer. A stromal gene signature reflecting bone remodeling and immune-related pathways was upregulated in high compared to low-Gleason grade cases. In validation data, the signature discriminated cases that developed metastasis from those that did not. These data suggest that the microenvironment may influence prostate cancer initiation, maintenance, and metastatic progression.

MicroRNA-193a-3p inhibits cell proliferation in prostate cancer by targeting cyclin D1.

MicroRNAs (miRNAs) are small non-coding RNAs that affect various biological processes by altering the expression of a target gene. An miRNA microarray analysis has previously revealed a significant decrease in miR-193a-3p levels in prostate cancer tissues compared with that in their benign prostate hyperplasia counterparts. However, the role of miR-193a-3p has yet to be elucidated. In the present study, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to evaluate the expression levels of miR-193a-3p in two human prostate cancer cell lines. Forced overexpression of miR-193a-3p was established by transfecting mimics into DU-145 and PC3 cell lines. Cell proliferation and the cell cycle were assessed using a cell viability assay, flow cytometry and a colony formation assay. In addition, the target gene of miR-193a-3p was determined by a luciferase assay, RT-qPCR and western blot analysis. The regulation of the cell cycle by miR-193a-3p was also evaluated by western blotting. The results demonstrated that miR-193a-3p expression levels were lower in prostate cancer cell lines as compared with the RWPE normal prostate epithelium cell line. Subsequent gain-of-function studies revealed that stable miR-193a-3p transfection inhibited cell viability, proliferation and colony formation, and induced G1 phase arrest in prostate cancer cells. A luciferase assay and western blot analysis identified cyclin D1 (CCND1) as a direct target gene of miR-193a-3p. In addition, the forced expression of CCND1 was able to counter the inhibitory effects of miR-193a-3p transfection in the prostate cancer cells. In summary, the results suggest that miR-193a-3p may inhibit the viability, proliferation and survival of prostate cancer cells by regulating the expression profile of CCND1, and that miR-193a-3p may be a novel therapeutic biomarker for prostate cancer.

Kallikrein-related peptidase 4 induces cancer-associated fibroblast features in prostate-derived stromal cells.

The reciprocal communication between cancer cells and their microenvironment is critical in cancer progression. Although involvement of cancer‐associated fibroblasts (CAF) in cancer progression is long established, the molecular mechanisms leading to differentiation of CAFs from normal fibroblasts are poorly understood. Here, we report that kallikrein‐related peptidase‐4 (KLK4) promotes CAF differentiation. KLK4 is highly expressed in prostate epithelial cells of premalignant (prostatic intraepithelial neoplasia) and malignant lesions compared to normal prostate epithelia, especially at the peristromal interface. KLK4 induced CAF‐like features in the prostate‐derived WPMY1 normal stromal cell line, including increased expression of alpha‐smooth muscle actin, ESR1 and SFRP1. KLK4 activated protease‐activated receptor‐1 in WPMY1 cells increasing expression of several factors (FGF1, TAGLN, LOX, IL8, VEGFA) involved in prostate cancer progression. In addition, KLK4 induced WPMY1 cell proliferation and secretome changes, which in turn stimulated HUVEC cell proliferation that could be blocked by a VEGFA antibody. Importantly, the genes dysregulated by KLK4 treatment of WPMY1 cells were also differentially expressed between patient‐derived CAFs compared to matched nonmalignant fibroblasts and were further increased by KLK4 treatment. Taken together, we propose that epithelial‐derived KLK4 promotes tumour progression by actively promoting CAF differentiation in the prostate stromal microenvironment.

Abstract 3690: The leukocyte chemoattractant chemerin modulates PTEN via CMKLR1 in human tumors

Abstract Background: Recent data in preclinical models has shown that phosphatase and tensin homolog (PTEN) loss correlated with decreased tumor immune cell infiltration as well as decreased response to T cell-based immunotherapy. Chemerin (RARRES2) is a recently identified endogenous leukocyte chemoattractant shown to recruit innate immune cells through its G-protein coupled receptor CMKLR1. Chemerin/RARRES2 is commonly downregulated in prostate and other cancers (e.g. sarcoma) compared to their normal tissue counterparts. Methylome-wide studies in multiple tumor types have identified RARRES2 as being one of the most hypermethylated genes, potentially leading to decreased chemerin expression. Our previous preclinical studies showed that forced overexpression of chemerin in tumors was capable of recruiting immune effector cells, including T cells, into the tumor microenvironment and suppressing tumor growth. Methods: In order to study the effects of chemerin overexpression on tumor cell intrinsic processes we exposed prostate and sarcoma tumor lines to exogenous recombinant chemerin in vitro. Evaluation of PTEN was performed at both the mRNA and protein levels, using both quantitative PCR and Western blotting, in comparison with normal prostate epithelia RWPE-1 as well as PTEN-null PC3 cells as controls. in vitro invasion assays were performed to investigate the functional impact of chemerin exposure on tumor intrinsic activity. Knockdown of CMKLR1 using siRNA was performed to determine its role in tumor response. Results: Using both prostate and sarcoma tumor lines, we found exogenous chemerin was able to significantly upregulate PTEN expression at both the mRNA and protein levels in a dose-response manner. Exposure to chemerin did not result in increased apoptosis or altered in vitro proliferation. Importantly, chemerin treatment significantly decreased in vitro tumor invasion. Knockdown studies showed CMKLR1 abrogation resulted in restored tumor migration, suggesting a link between this GPCR and PTEN expression and activity. Conclusions: For the first time, to our knowledge, we have shown a link between chemerin and PTEN expression and activity in both prostate and sarcoma tumor lines. Our collective study shows chemerin’s ability to upregulate PTEN activity and to mitigate tumor cell migration via CMKLR1. This work has functional implications on both tumor cell intrinsic and extrinsic responses to chemerin-based immunotherapeutic strategies. Further studies are needed to investigate the interaction between chemerin and PTEN signaling, and its connection to oncogenic signaling pathways manipulated in malignant tumors. Additionally, future in vivo studies using these tumor lines will help further elucidate the chemerin-PTEN axis and its role in tumor immunosurveillance. We hypothesize that increased chemerin-driven PTEN activity may help facilitate an improved immunotherapy response and functional ability to attack cancer cells. Citation Format: Keith R. Rennier, Ping Wang, Robert Crowder, Russell K. Pachynski. The leukocyte chemoattractant chemerin modulates PTEN via CMKLR1 in human tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3690. doi:10.1158/1538-7445.AM2017-3690

Dual action of high estradiol doses on MNU-induced prostate neoplasms in a rodent model with high serum testosterone: Protective effect and emergence of unstable epithelial microenvironment.

Estrogens are critical players in prostate growth and disease. Estrogen therapy has been the standard treatment for advanced prostate cancer for several decades; however, it has currently been replaced by alternative anti-androgenic therapies. Additionally, studies of its action on prostate biology, resulting from an association between carcinogens and estrogen, at different stages of life are scarce or inconclusive about its protective and beneficial role on induced-carcinogenesis. Thus, the aim of this study was to determine whether estradiol exerts a protective and/or stimulatory role on N-methyl-N-nitrosurea-induced prostate neoplasms. We adopted a rodent model that has been used to study induced-prostate carcinogenesis: the Mongolian gerbil. We investigated the occurrence of neoplasms, karyometric patterns, androgen and estrogen receptors, basal cells, and global methylation status in ventral and dorsolateral prostate tissues. Histopathological analysis showed that estrogen was able to slow tumor growth in both lobes after prolonged treatment. However, a true neoplastic regression was observed only in the dorsolateral prostate. In addition to the protective effects against neoplastic progression, estrogen treatment resulted in an epithelium that exhibited features distinctive from a normal prostate, including increased androgen-insensitive basal cells, high androgens and estrogen receptor positivity, and changes in DNA methylation patterns. Estrogen was able to slow tumor growth, but the epithelium exhibited features distinct from a normal prostatic epithelium, and this unstable microenvironment could trigger lesion recurrence over time.

Xyloglucan, hibiscus and propolis for the prevention of urinary tract infections: results of in vitro studies.

To assess the properties of a medical device containing xyloglucan, propolis and hibiscus to create a bioprotective barrier to avoid the contact of uropathogenic Escherichia coli strains on cell walls in models of intestinal (CacoGoblet) and uroepithelial (RWPE-1) cells (derived from normal human prostate epithelium). Two uropathogenic E. coli strains (expressing type 1 fimbriae and P fimbriae) were used to assess, by electronic microscopy and ELISA, the barrier properties of the medical device. The antimicrobial activity was assessed in broth dilution assays. The three components (xyloglucan, propolis and hibiscus) did not alter E. coli cell integrity in intestinal and uroepithelial cell models and were devoid of antibacterial activity. The three components avoided bacterial contact in both cell monolayers. The nonpharmacological barrier properties of xyloglucan, propolis and hibiscus confirm the role of the medical device for the management of urinary tract infections.

Analysis of spatial heterogeneity in normal epithelium and preneoplastic alterations in mouse prostate tumor models

Cancer involves histological changes in tissue, which is of primary importance in pathological diagnosis and research. Automated histological analysis requires ability to computationally separate pathological alterations from normal tissue with all its variables. On the other hand, understanding connections between genetic alterations and histological attributes requires development of enhanced analysis methods suitable also for small sample sizes. Here, we set out to develop computational methods for early detection and distinction of prostate cancer-related pathological alterations. We use analysis of features from HE stained histological images of normal mouse prostate epithelium, distinguishing the descriptors for variability between ventral, lateral, and dorsal lobes. In addition, we use two common prostate cancer models, Hi-Myc and Pten+/− mice, to build a feature-based machine learning model separating the early pathological lesions provoked by these genetic alterations. This work offers a set of computational methods for separation of early neoplastic lesions in the prostates of model mice, and provides proof-of-principle for linking specific tumor genotypes to quantitative histological characteristics. The results obtained show that separation between different spatial locations within the organ, as well as classification between histologies linked to different genetic backgrounds, can be performed with very high specificity and sensitivity.

Overexpression of the A Disintegrin and Metalloproteinase ADAM15 is linked to a Small but Highly Aggressive Subset of Prostate Cancers

The A Disintegrin and Metalloproteinase (ADAM) family of endopeptidases plays a role in many solid cancers and includes promising targets for anticancer therapies. Deregulation of ADAM15 has been linked to tumor aggressiveness and cell line studies suggest that ADAM15 overexpression may also be implicated in prostate cancer. To evaluate the impact of ADAM15 expression and its relationship with key genomic alterations, a tissue microarray containing 12,427 prostate cancers was analyzed by immunohistochemistry. ADAM15 expression was compared to phenotype, prognosis and molecular features including TMPRSS2:ERG fusion and frequent deletions involving PTEN, 3p, 5q and 6q. Normal prostate epithelium did not show ADAM15 staining. In prostate cancers, negative, weak, moderate, and strong ADAM15 staining was found in 87.7%, 3.7%, 5.6%, and 3.0% of 9826 interpretable tumors. Strong ADAM15 staining was linked to high Gleason grade, advanced pathological tumor stage, positive nodal stage and resection margin. ADAM15 overexpression was also associated with TMPRSS2:ERG fusions and PTEN deletions (P<.0001) but unrelated to deletions of 3p, 5q and 6q. In univariate analysis, high ADAM15 expression was strongly linked to PSA recurrence (P<.0001). However, in multivariate analyses this association was only maintained if the analysis was limited to preoperatively available parameters in ERG-negative cancers. The results of our study demonstrate that ADAM15 is strongly up regulated in a small but highly aggressive fraction of prostate cancers. In these tumors, ADAM15 may represent a suitable drug target. In a preoperative scenario, ADAM15 expression measurement may assist prognosis assessment, either alone or in combination with other markers.

High-Level γ-Glutamyl-Hydrolase (GGH) Expression is Linked to Poor Prognosis in ERG Negative Prostate Cancer.

γ-glutamyl-hydrolase (GGH) is a ubiquitously-expressed enzyme that regulates intracellular folate metabolism for cell proliferation, DNA synthesis, and repair. Employing GGH immunohistochemistry on a tissue microarray with 12,427 prostate cancers, we found that GGH expression was negative to low in normal prostate epithelium, whereas 88.3% of our 10,562 interpretable cancers showed GGH expression. GGH staining was considered as low intensity in 49.6% and as high intensity in 38.6% of cancers. High GGH expression was linked to the TMPRSS2:ERG-fusion positive subset of cancers (p < 0.0001), advanced pathological tumor stage, and high Gleason grade (p < 0.0001 each). Further analysis revealed that these associations were merely driven by the subset of ERG-negative cancers, High GGH expression was weakly linked to early biochemical recurrence in ERG negative cancers (p < 0.0001) and independent from established histo-pathological parameters. Moreover, GGH expression was linked to features of genetic instability, including presence of recurrent deletions at 3p, 5q, 6q, and 10q (PTEN, p ≤ 0.01 each), as well as to accelerated cell proliferation as measured by Ki67 immunohistochemistry (p < 0.0001). In conclusion, the results of our study identify GGH as an ERG subtype specific molecular marker with modest prognostic relevance, which may have clinical relevance if analyzed in combination with other molecular markers.

The role of CYP17A1 in prostate cancer development: structure, function, mechanism of action, genetic variations and its inhibition.

Androgens play an important role during the development of both normal prostate epithelium and prostate cancer and variants of genes involved in androgen metabolism may be related to an increased risk of prostate disease. Cytochrome P450 17α-hydroxylase/17,20-lyase (CYP17A1) is a key regulatory enzyme in the steroidogenic pathway; it catalyses both 17α-hydroxylase and 17,20-lyase activities and is essential for the production of both androgens and glucocorticoids. In this review, we focus on the structure and enzymatic activity of CYP17A1 and the mechanism of modulation of CYP17A1 activities. We discuss the relationship between common genetic variations in CYP17A1 gene and prostate cancer risk and the main effects of these variations on the prediction of susceptibility and clinical outcomes of prostate cancer patients. The mechanism of action, the efficacy and the clinical potential of CYP17A1 inhibitors in prostate cancer are also summarized.

Characterization of an in vitro model to study the role of human Polyomavirus BK in prostate cancer

Prostate cancer (PCa) is one of the most common male neoplasm in the western world, being the most commonly diagnosed non-skin cancer and the second leading cause of cancer death. Various potential risk factors exist for the initial triggering events, including exposure to infectious agents, such as the human Polyomavirus BK (BKV). BKV is a good candidate as risk factor of PCa because it naturally infects the human reno-urinary tract, it establishes latency, and encodes oncoproteins that interfere with tumor suppressors pathways, thus altering the normal progression of cell cycle. Previous studies suggested a potential association between BKV and PCa, revealing that the prevalence of BKV was significantly higher in cancer than in control tissues, with a significant association between viral expression and cancer. However, this hypothesis is controversial because BKV is not restricted to tumor tissues but also infects healthy individuals in a high percentage. Moreover, an in vitro model of BKV infection in prostate cells is not available to understand the role for BKV in pathogenesis of PCa. Our aims were to determine whether BKV a) could infect normal epithelial prostate cells, b) affects cell phenotype and c) affects the phenotype of human prostate tumor cell line PC3. For this purpose normal epithelial prostate cell line RWPE-1 and prostate cancer cells PC3 were infected with BKV for 21 days. Cell proliferation, epithelial-to-mesenchymal markers (EMT) and invasion potential were analyzed by, respectively, MTT, immunofluorescence and SDS-zymography. Our results show that cell proliferation was increased or decreased by BKV, respectively, in RWPE-1 and PC3 cells. BKV induced E-cadherin downregulation and vimentin expression in both control and BKV-infected cells RWPE-1, suggesting that uninfected cells underwent EMT. Matrix metalloproteinase-2 and 9 activity was increased in RWPE-1 cells after BKV infection. By contrast, BKV did not significantly modified the phenotype of PC3 cells. These preliminary results suggest that normal epithelial prostate cells RWPE-1 and PC3 are susceptible and permissive to BKV infection. However, RWPE-1 cells exhibit some phenotype modifications related to EMT, possibly induced by the papilloma virus used to obtain their immortalization, thus suggesting that further experiments will be necessary to define if they represent a good experimental model to study prostate cancer.

Alternative Synthesis Route of Biocompatible Polyvinylpyrrolidone Nanoparticles and Their Effect on Pathogenic Microorganisms.

Herein we describe a novel alternative synthesis route of polyvinylpyrrolidone nanoparticles using salting-out method at a temperature close to polyvinylpyrrolidone decomposition. At elevated temperatures, the stability of polyvinylpyrrolidone decreases and the opening of pyrrolidone ring fractions occurs. This leads to cross-linking process, where separate units of polyvinylpyrrolidone interact among themselves and rearrange to form nanoparticles. The formation/stability of these nanoparticles was confirmed by transmission electron microscopy, X-ray photoelectron spectroscopy, mass spectrometry, infrared spectroscopy, and spectrophotometry. The obtained nanoparticles possess exceptional biocompatibility. No toxicity and genotoxicity was found in normal human prostate epithelium cells (PNT1A) together with their high hemocompatibility. The antimicrobial effects of polyvinylpyrrolidone nanoparticles were tested on bacterial strains isolated from the wounds of patients suffering from hard-to-heal infections. Molecular analysis (qPCR) confirmed that the treatment can induce the regulation of stress-related survival genes. Our results strongly suggest that the polyvinylpyrrolidone nanoparticles have great potential to be developed into a novel antibacterial compound.

Identification of microRNA signature and potential pathway targets in prostate cancer.

Prostate cancer (PC) is the most common and the second leading cause of cancer-related death among American men. Early diagnosis is a prerequisite to improving therapeutic benefits. However, the current clinical biomarkers for PC do not reliably decipher indolent PC from other urogenital disorders. Thus, effective clinical intervention necessitates development of new biomarkers for early detection of PC. The present study aimed to identify the miRNA signature in organ-confined (Gleason Score 6) prostate tumors. MicroRNA (miRNA/miR) array analysis identified 118 upregulated and 73 downregulated miRNAs in microdissected tumors in comparison to matched neighboring normal prostate epithelium. The miRs-Plus-A1083, -92b-5p, -18a-3p, -19a-3p, -639, -3622b-3p, -3189-3p, -155-3p, -410, -1179, 548b-5p, and -4469 are predominantly expressed (7-11-fold), whereas miRs-595, 4490, -3120-5p, -1299, -21-5p, -3677-3, -let-7b-5p, -5189, 3-121-5p, -4518, -200a-5p, -3682-5p, -3689d, -3149 represent the most downregulated (12-113-fold) miRNAs in microdissected prostate tumors. The array expression profile of selected miRNA signature and their potential mRNA targets was validated by qRT-PCR analysis in PC cell lines. Integrated in silico and computational prediction analyses demonstrated that the dysregulated miRNA signature map to key regulatory factors involved in tumorigenesis, including cell cycle, apoptosis, and p53 pathways. The newly identified miRNA signature has potential clinical utility as biomarkers, prognostic indicators, and therapeutic targets for early detection of PC. Further studies are needed to assess the functional significance and clinical usefulness of the identified miRNAs. Impact Statement To our knowledge his is the first study of identifying miRNA signatures in microdissected indolent (Gleason score 6) prostate cancer in comparison to matched normal prostate epithelium. By employing in silico and computational prediction analysis, the study provides a landscape of potential miRNA targets and key cellular pathways involved in prostate tumorigenesis. Identification if miRNAs and their relevant targets and pathways pave the way for underpinning their mechanistic role of miRNAs in human prostate tumorigenesis, and possibly other human cancers. Importantly, the outcome of the study has important clinical implications for the management of prostate cancer, including the use of miRNA(s) as biomarkers for early detection of prostate cancer.

Ornithine Decarboxylase Is Sufficient for Prostate Tumorigenesis via Androgen Receptor Signaling

Increased polyamine synthesis is known to play an important role in prostate cancer. We aimed to explore its functional significance in prostate tumor initiation and its link to androgen receptor (AR) signaling. For this purpose, we generated a new cell line derived from normal epithelial prostate cells (RWPE-1) with overexpression of ornithine decarboxylase (ODC) and used it for invitro and invivo experiments. We then comprehensively analyzed the expression of the main metabolic enzymes of the polyamine pathway and spermine abundance in 120 well-characterized cases of human prostate cancer and high-grade prostate intraepithelial neoplasia (HGPIN). Herein, we show that the ODC-overexpressing prostate cells underwent malignant transformation, revealing that ODC is sufficient for de novo tumor initiation in 94% of injected mice. This oncogenic capacity was acquired through alteration of critical signaling networks, including AR, EIF2, and mTOR/MAPK. RNA silencing experiments revealed the link between AR signaling and polyamine metabolism. Human prostate cancers consistently demonstrated up-regulation of the main polyamine enzymes analyzed (ODC, polyamine oxidase, and spermine synthase) and reduction of spermine. This phenotype was also dominant in HGPIN, rendering it a new biomarker of malignant transformation. In summary, we report that ODC plays a key role in prostate tumorigenesis and that the polyamine pathway is altered as early as HGPIN.

Promoter methylation of the immune checkpoint receptor PD-1 (PDCD1) is an independent prognostic biomarker for biochemical recurrence-free survival in prostate cancer patients following radical prostatectomy

ABSTRACTBiomarkers that facilitate the prediction of disease recurrence in prostate cancer (PCa) may enable physicians to personalize treatment for individual patients. In the current study, PD-1 (PDCD1) promoter methylation was assessed in a cohort of 498 PCa patients included in The Cancer Genome Atlas (TCGA) and a second cohort of 300 PCa cases treated at the University Hospital of Bonn.In the TCGA cohort, the PD-1 promoter was significantly hypermethylated in carcinomas versus normal prostatic epithelium (55.5% vs. 38.2%, p < 0.001) and PD-1 methylation (mPD-1) inversely correlated with PD-1 mRNA expression in PCa (Spearman's ρ = −0.415, p < 0.001). In both cohorts, mPD-1 significantly correlated with preoperative prostate specific antigen (PSA). In univariate Cox Proportional Hazard analysis, mPD-1 served as a significant prognostic factor for biochemical recurrence (BCR)-free survival (Hazard ratio: HR = 2.35 [1.35–4.10], p = 0.003, n = 410) in the TCGA cohort. In multivariate analysis, mPD-1 was shown to add significant independent prognostic information adjunct to pathologic tumor category (pT) and Gleason grading group (HR = 2.08 [1.16–3.74], p = 0.014, n = 350).PD-1 promoter methylation analyses could thus potentially aid the identification of patients which might benefit from adjuvant treatment after radical prostatectomy. Moreover, our data suggest an intrinsic role of PD-1 in PCa carcinogenesis and disease progression, which needs to be addressed in future studies.

αvβ6 Integrin Promotes Castrate-Resistant Prostate Cancer through JNK1-Mediated Activation of Androgen Receptor.

Androgen receptor signaling fuels prostate cancer and is a major therapeutic target. However, mechanisms of resistance to therapeutic androgen ablation are not well understood. Here, using a prostate cancer mouse model, Pten(pc-/-), carrying a prostate epithelial-specific Pten deletion, we show that the αvβ6 integrin is required for tumor growth in vivo of castrated as well as of noncastrated mice. We describe a novel signaling pathway that couples the αvβ6 integrin cell surface receptor to androgen receptor via activation of JNK1 and causes increased nuclear localization and activity of androgen receptor. This downstream kinase activation by αvβ6 is specific for JNK1, with no involvement of p38 or ERK kinase. In addition, differential phosphorylation of Akt is not observed under these conditions, nor is cell morphology affected by αvβ6 expression. This pathway, which is specific for αvβ6, because it is not regulated by a different αv-containing integrin, αvβ3, promotes upregulation of survivin, which in turn supports anchorage-independent growth of αvβ6-expressing cells. Consistently, both αvβ6 and survivin are significantly increased in prostatic adenocarcinoma, but are not detected in normal prostatic epithelium. Neither XIAP nor Bcl-2 is affected by αvβ6 expression. In conclusion, we show that αvβ6 expression is required for prostate cancer progression, including castrate-resistant prostate cancer; mechanistically, by promoting activation of JNK1, the αvβ6 integrin causes androgen receptor-increased activity in the absence of androgen and consequent upregulation of survivin. These preclinical results pave the way for further clinical development of αvβ6 antagonists for prostate cancer therapy. Cancer Res; 76(17); 5163-74. ©2016 AACR.