Cocaine and amphetamine regulated transcript (CART): a newly characterized neuropeptide in human prostate.

Cocaine and amphetamine regulated transcript (CART) is a somatostatin-like polypeptide. CART has been localized in the CNS, hypothalamo-pituitary-adrenocortical (HPA) axis, pancreatic islets and enteric nervous system. We investigated the cellular localization of CART in normal human prostate, benign prostatic hyperplasia, prostatic intraepithelial neoplasia and acinar adenocarcinoma. CART was assessed using immunohistochemistry (IHC) and in situ hybridization (ISH), and its gene expression was identified by RTqPCR. We found cellular expression of CART in both normal prostatic luminal secretory epithelial cells neuroendocrine cells (NEC) of both ducts and acini. The cellular appearance indicated a cycle of neuropeptide synthesis and secretion as validated by ISH/IHC concordance. RTqPCR analysis also validated the immunohistochemical data and gene expression, which both indicated low to moderate expression in prostatic tissues. CART expression also was increased in both neuroendocrine and glandular epithelial cell populations from samples of benign prostatic hyperplasia as validated by IHC, ISH and RTqPCR. CART expression was markedly diminished and, in some cases, entirely absent in tissues of prostatic intraepithelial neoplasia and adenocarcinoma. Owing to loss of CART expression in adenocarcinoma and its increase in benign prostatic hyperplasia, CART may prove to be an important prostate marker.

DIAGNOSTIC UTILITY OF IMMUNOHISTOCHEMICAL EXPRESSION OF KI!67, P63 AND AMACR IN PROSTATE INTRAEPITHELIAL NEOPLASIA.

OBJECTIVE: The aim: To determine malignant transformation and progression ability of high grade and low grade prostate intraepithelial neoplasia with the help of immunohistochemical method. PATIENTS AND METHODS: Materials and methods: The results of examination of 93 patients with PIN (50 patients with high grade PIN and 43 patients with low grade PIN) were assessed comparatively using immunohistochemical markers. Semiquantitative method was used to evaluate !"-67, #63 and AMACR tissue expression with four grades from "+" to "++++" or from 1 to 4 points: '+' - low reaction, '++' - poor reaction, '+++' - moderate reaction and '++++" - intense reaction. RESULTS: Results: There were statistically significant differences in immunohistochemical expression rates between HGPIN and LGPIN. Patients with HGPIN had higher Ki-67 and AMACR expression rate and lower p63 expression rate than patients with LGPIN. Intense and moderate Ki-67 expression was detected in HGPIN more often, in 24 % and 11 % respectively. Low and moderate AMACR expression was determined in HGPIN more often, in 28 % and 5 % respectively. Low and not evident p63 expression was observed in HGPIN more often, in 36 % and 8 % respectively. CONCLUSION: Conclusions: HGPIN has common morphological peculiarities with prostate adenocarcinoma. Immunohistochemical detection of Ki-67, p63 and AMACR is aimed to differentiate among patients with PIN a group of high malignant transformation risk.

High-lipid nutritional environment in different ontogenetic periods induce developmental programming of rat prostate at aging.

In brief: Maternal obesity plus high-fat diet in breastfeeding induces stromal hyperplasia and diffuse acinar atrophy in the rat prostate at aging, related to dyslipidemia and testosterone reduction. The high-lipid nutritional environment from intrauterine and throughout life favors the development of prostatic intraepithelial neoplasia and aggravated degenerative alterations in the gland. Abstract: Maternal obesity and high-fat diet (HFD) affect permanently prostate histophysiology in adulthood, but the consequences during aging are unknown. Here, we evaluated the prostate alterations in middle-aged rats subjected to a high-lipid nutritional environment (HLE) in different ontogenetic periods. Wistar rats (56 weeks of age) were assigned into groups exposed to standard nutrition (C) or HLE during gestation (G), gestation and lactation (GL), from lactation onward (L), from weaning onward (W) and from gestation onward (AL). HLE in the periods after weaning consisted of HFD (20% fat), and during gestation and lactation it also included previous maternal obesity induced by the HFD. HLE increased total cholesterol and triglyceride levels in all groups and led to insulin resistance in GL and AL and obesity in L. Serum testosterone levels decreased ~67% in GL, ~146% in L and W, and ~233% in AL. Histological and stereological analysis revealed an increment of the stromal compartment and collagen fibers in the prostates of all HLE groups, as well as degenerative lesions, such as cell vacuolation and prostate concretions. HLE aggravated acinar atrophy in G, GL, and L, and in AL it reached more than 50% of the prostate area for most animals. The foci of prostatic intraepithelial neoplasia increased in AL. Tissue expression of androgen receptor did not vary among groups, except for a higher stromal expression for G and GL. Even when restricted to gestation and lactation, HLE induces diffuse acinar atrophy in the aging prostate and worsens degenerative and premalignant lesions when it continues throughout life.

Hypoxia-mediated stabilization of HIF1A in prostatic intraepithelial neoplasia promotes cell plasticity and malignant progression.

Prostate cancer (PCa) is a leading cause of cancer-related deaths. The slow evolution of precancerous lesions to malignant tumors provides a broad time frame for preventing PCa. To characterize prostatic intraepithelial neoplasia (PIN) progression, we conducted longitudinal studies on Pten(i)pe-/- mice that recapitulate prostate carcinogenesis in humans. We found that early PINs are hypoxic and that hypoxia-inducible factor 1 alpha (HIF1A) signaling is activated in luminal cells, thus enhancing malignant progression. Luminal HIF1A dampens immune surveillance and drives luminal plasticity, leading to the emergence of cells that overexpress Transglutaminase 2 (TGM2) and have impaired androgen signaling. Elevated TGM2 levels in patients with PCa are associated with shortened progression-free survival after prostatectomy. Last, we show that pharmacologically inhibiting HIF1A impairs cell proliferation and induces apoptosis in PINs. Therefore, our study demonstrates that HIF1A is a target for PCa prevention and that TGM2 is a promising prognostic biomarker of early relapse after prostatectomy.

Estrogen receptor expression is modulated in human and mouse prostate epithelial cells during cancer progression.

Substantial data posit estrogen receptors (ERs) as promising targets for prostate cancer (PCa) therapeutics. However, the trials on assessing the chemo-preventive or therapeutic potential of ER targeting drugs or selective estrogen receptor modulators (SERMs) have not yet established their clinical benefits. This could be ascribed to a possible modulation in the ER expression during PCa progression. Further it is warranted to test various ER targeting drugs in appropriate preclinical models that simulate human ER expression pattern during PCa progression. The study was undertaken to revisit the existing data on the epithelial ER expression pattern in human cancerous prostates and experimentally determine whether these patterns are replicated in TRAMP (Transgenic Adenocarcinoma of Mouse Prostate) mice, a model for human PCa. Estradiol (E2) binding to the plasma membrane of the epithelial cells and its modulation during the PCa progression in TRAMP were also investigated. A reassessment of the existing data revealed a trend towards downregulation in the epithelial expression of wild-type ESR1 transcripts in high-grade PCa, compared to non-cancerous prostate in humans. Next, epithelial cell-enriched populations from TRAMP prostates (TP) displaying low-grade prostatic intraepithelial neoplasia (LGPIN), high-grade PIN (HGPIN), HGPIN with well-differentiated carcinoma (PIN + WDC), WDC (equivalent to grade 2/3 human PCa), and poorly-differentiated carcinoma (PDC-equivalent to grade 4/5 human PCa) revealed significantly higher Esr1 and Esr2 levels in HGPIN and significantly reduced levels in WDC, compared to respective age-matched control prostates. These patterns for the nuclear ERs were similar to the trend shown by E2 binding to the plasma membrane of the epithelial cells during PCa progression in TRAMP. E2 binding to epithelial cells (EpCAM+), though significantly higher in TPs displaying LGPIN, decreased significantly as the disease progressed to WDC. The study highlights a reduction in the epithelial ESR level with the PCa progression and this pattern was evident in both humans and TRAMP. These observations may have major implications in refining PCa therapeutics targeting ER.

Evaluation of angiogenic apelin/apelin receptor axis in normal prostate, high grade prostatic intraepithelial neoplasia and prostatic adenocarcinoma.

INTRODUCTION AND OBJECTIVES: Prostate cancer is one of the most commonly diagnosed cancers in American men. Apelin is an endogenous peptide identified as the ligand of the G protein-associated apelin receptor. Apelin and apelin receptor have many tissues distribution and they participate in pathological processes, such as cancer. Apelin stimulates cancer angiogenesis. However, there are insufficient data in the literature regarding the role of apelin/apelin receptor in normal tissue, highgrade prostatic intraepithelial neoplasia, and prostatic adenocarcinoma tissues. Therefore, this study aimed to investigate the apelin and apelin receptor expression levels in tissues of normal prostate tissue, high-grade prostatic intraepithelial neoplasia, and prostatic adenocarcinoma. MATERIALS AND METHODS: In this study, 38 samples of patients undergoing radical prostatectomy were used. Among 38 samples; 20 patients were with prostatic adenocarcinoma, 18 patients were with high-grade prostatic intraepithelial neoplasia and adjacent normal prostatic tissue areas. The immunolocalisation of apelin and apelin receptor in these tissues were determined immunohistochemically. RESULTS: Apelin and apelin receptor expressions were higher in prostatic adenocarcinoma than normal prostate tissue and high-grade prostatic intraepithelial neoplasia. Apelin receptor expression was also increased in high-grade prostatic intraepithelial neoplasia compared to normal tissue. CONCLUSION: Apelin and apelin receptor are increase in the process of prostate carcinogenesis. This increase may adversely affect the clinical course of prostate cancer patients by stimulating angiogenesis, which is important for invasion and metastasis in prostate cancer.

Single-cell analyses unravel cell type-specific responses to a vitamin D analog in prostatic precancerous lesions.

Epidemiological data have linked vitamin D deficiency to the onset and severity of various cancers, including prostate cancer, and although in vitro studies have demonstrated anticancer activities for vitamin D, clinical trials provided conflicting results. To determine the impact of vitamin D signaling on prostatic precancerous lesions, we treated genetically engineered Pten(i)pe-/- mice harboring prostatic intraepithelial neoplasia (PIN) with Gemini-72, a vitamin D analog with reported anticancer activities. We show that this analog induces apoptosis in senescent PINs, normalizes extracellular matrix remodeling by stromal fibroblasts, and reduces the prostatic infiltration of immunosuppressive myeloid-derived suppressor cells. Moreover, single-cell RNA-sequencing analysis demonstrates that while a subset of luminal cells expressing Krt8, Krt4, and Tacstd2 (termed luminal-C cells) is lost by such a treatment, antiapoptotic pathways are induced in persistent luminal-C cells. Therefore, our findings delineate the distinct responses of PINs and the microenvironment to Gemini-72, and shed light on mechanisms that limit treatment's efficacy.

Comparative study of immunohistochemical expression of ERG and MAGI2 in prostatic carcinoma.

Diagnosis of Prostatic adenocarcinoma (PAC) is still a problematic issue. The objective of this study was to evaluate the diagnostic and prognostic value of ERG immunohistochemical (IHC) expression compared to MAGI2. MATERIALS AND METHODS: This study was conducted on 56 cases of PAC and 29 cases of nodular prostatic hyperplasia (NPH). IHC staining for ERG and MAGI2 was applied to archival formalin-fixed paraffin-embedded blocks. Semi-quantitative scoring was compared and correlated with clinicopathologic parameters and the Ki-67 index. RESULTS: Revealed positive ERG in 51.8% of PAC while all NPH cases were negative. On the other hand, MAGI2 was detected in 91.1% of PAC versus 17.2% of NPH. Using ROC curve, the ERG showed 53.6% sensitivity, 100% specificity, 76.5% diagnostic accuracy (DA) and area under the ROC curve 0.768 in comparison to MAGI2 that showed (91.1%, 86.2%, 88.25% and 0.948 respectively). Analysis of the combined use of the two markers revealed 95% sensitivity, 100% specificity, and 94% DA when tested synchronously. Moreover, a statistically significant inverse relationship could be detected between ERG expression and the Gleason grading group (P = 0.01) and Ki-67 index (P < 0.001). In addition, high-grade prostatic intraepithelial neoplasia (HGPIN) adjacent to carcinoma; showed positive expressions in (1/11 cases, 9.11%) for ERG and (6/11 cases, 54%) for MAGI2. CONCLUSION: This study recommends using both ERG and MAGI2 in a cocktail for better diagnostic validity of PAC. Only ERG expression could be a good prognostic indicator.

Macrophages expedite cell proliferation of prostate intraepithelial neoplasia through their downstream target ERK.

The risk factors for prostate cancer include a high-fat diet and obesity, both of which are associated with an altered cell environment including increased inflammation. It has been shown that chronic inflammation due to a high-fat diet or bacterial infection has the potential to accelerate prostate cancer as well as its precursor, prostatic intraepithelial neoplasia (PIN), development. However, the underlying mechanism of how chronic inflammation promotes prostate cancer development, especially PIN, remains unclear. In this study, we showed that more macrophages were present in PIN areas as compared to the normal areas of human prostate. When co-culturing PIN cells with macrophages in 3D, more PIN cells had nuclear localized cyclin D1, indicating that macrophages enhanced PIN cell proliferation. We identified ICAM-1 and CCL2 as chemoattractants expressed by PIN cells to recruit macrophages. Furthermore, we discovered that macrophage-secreted cytokines including C5a, CXCL1, and CCL2 were responsible for increased PIN cell proliferation. These three cytokines activated ERK and JNK signaling in PIN cells through a ligand-receptor interaction. However, only blockade of ERK abolished macrophage cytokines-induced cell proliferation of PIN. Overall, our results provide a mechanistic view on how macrophages activated through chronic inflammation can expedite PIN progression during prostate cancer development. The information from our work can facilitate a comprehensive understanding of prostate cancer development, which is required for improvement of current strategies for prostate cancer therapy.

Galectin-3 in Prostate Cancer Stem-Like Cells Is Immunosuppressive and Drives Early Metastasis.

Galectin-3 (Gal-3) is an extracellular matrix glycan-binding protein with several immunosuppressive and pro-tumor functions. The role of Galectin-3 in cancer stem-like cells (CSCs) is poorly investigated. Here, we show that prostate CSCs also colonizing prostate-draining lymph nodes of transgenic adenocarcinoma of the mouse prostate (TRAMP) mice overexpress Gal-3. Gal-3 contributes to prostate CSC-mediated immune suppression because either Gal-3 silencing in CSCs, or co-culture of CSCs and T cells in the presence of the Gal-3 inhibitor N-Acetyl-D-lactosamine rescued T cell proliferation. N-Acetyl-D-lactosamine also rescued the proliferation of T cells in prostate-draining lymph nodes of TRAMP mice affected by prostate intraepithelial neoplasia. Additionally, Gal-3 impacted prostate CSC tumorigenic and metastatic potential in vivo, as Gal-3 silencing in prostate CSCs reduced both primary tumor growth and secondary invasion. Gal-3 was also found expressed in more differentiated prostate cancer cells, but with different intracellular distribution as compared to CSCs, which suggests different functions of Gal-3 in the two cell populations. In fact, the prevalent nuclear and cytoplasmic distribution of Gal-3 in prostate CSCs made them less susceptible to apoptosis, when compared to more differentiated prostate cancer cells, in which Gal-3 was predominantly intra-cytoplasmic. Finally, we found Gal-3 expressed in human and mouse prostate intraepithelial neoplasia lesions and in metastatic lymph nodes. All together, these findings identify Gal-3 as a key molecule and a potential therapeutic target already in the early phases of prostate cancer progression and metastasis.

Evidence that EZH2 Deregulation is an Actionable Therapeutic Target for Prevention of Prostate Cancer.

Chemoprevention trials for prostate cancer by androgen receptor or androgen synthesis inhibition have proven ineffective. Recently, it has been demonstrated that the histone methlytransferase, EZH2 is deregulated in mouse and human high-grade prostatic intraepithelial neoplasia (HG-PIN). Using preclinical mouse and human models of prostate cancer, we demonstrate that genetic and chemical disruption of EZH2 expression and catalytic activity reversed the HG-PIN phenotype. Furthermore, inhibition of EZH2 function was associated with loss of cellular proliferation and induction of Tp53-dependent senescence. Together, these data provide provocative evidence for EZH2 as an actionable therapeutic target toward prevention of prostate cancer.

CIP2A expression in high grade prostatic intraepithelial neoplasia and prostate adenocarcinoma: a tissue microarray study.

INTRODUCTION: CIP2A is an oncoprotein involved in the progression of several human malignancies. It has recently been described as a prognostic marker in many cancers. The present study aimed to investigate the immunohistochemical expression of CIP2A in benign prostatic hyperplasia (BPH), high grade prostatic intraepithelial neoplasia (HGPIN) and prostate cancer (PC), and to analyse the association with the clinicopathological parameters in PC cases to define its role in the development and progression of PC. MATERIALS AND METHODS: Immunohistochemical staining for CIP2A was performed on the tissue microarray sections of 105 PC, 27 HGPIN and 27 BPH tissues. The CIP2A expression scores were compared with several clinicopathological parameters. RESULTS: CIP2A was expressed in 96,2% of PC, 55,6% of HGPIN and 40,7% of BPH tissues. The expression of CIP2A in PC was significantly higher than in HGPIN (p<0.0001) and BPH (p<0.0001) cases. CIP2A expression score was significantly associated with Gleason score (p=0.032) and lymphovascular invasion (p=0.039). Nevertheless, there was no statistically significant association between the expression of CIP2A and perineural invasion, pT stage, metastasis and recurrence (p>0.05). Multivariate analysis indicated that GS, lymphovascular invasion, distant metastasis were independent prognostic factors for PC patients but, CIP2A expression score was not found to be a prognostic factor. Additionally, there was no significant difference between the survival times of patients according to CIP2A expression (p=0.174). CONCLUSIONS: According to our results, the expression of CIP2A protein is increased in PC and its expression may be involved in the development, differentiation, and aggressiveness of PC. However, further studies are needed to confirm our findings and to clarify the role of CIP2A in the development of PC.

ETV4 promotes late development of prostatic intraepithelial neoplasia and cell proliferation through direct and p53-mediated downregulation of p21.

BACKGROUND: ETV4 is one of the ETS proteins overexpressed in prostate cancer (PC) as a result of recurrent chromosomal translocations. In human prostate cell lines, ETV4 promotes migration, invasion, and proliferation; however, its role in PC has been unclear. In this study, we have explored the effects of ETV4 expression in the prostate in a novel transgenic mouse model. METHODS: We have created a mouse model with prostate-specific expression of ETV4 (ETV4 mice). By histochemical and molecular analysis, we have investigated in these engineered mice the expression of p21, p27, and p53. The implications of our in vivo findings have been further investigated in human cells lines by chromatin-immunoprecipitation (ChIP) and luciferase assays. RESULTS: ETV4 mice, from two independent transgenic lines, have increased cell proliferation in their prostate and two-thirds of them, by the age of 10 months, developed mouse prostatic intraepithelial neoplasia (mPIN). In these mice, cdkn1a and its p21 protein product were reduced compared to controls; p27 protein was also reduced. By ChIP assay in human prostate cell lines, we show that ETV4 binds to a specific site (-704/-696 bp upstream of the transcription start) in the CDKN1A promoter that was proven, by luciferase assay, to be functionally competent. ETV4 further controls CDKN1A expression by downregulating p53 protein: this reduction of p53 was confirmed in vivo in ETV4 mice. CONCLUSIONS: ETV4 overexpression results in the development of mPIN but not in progression to cancer. ETV4 increases prostate cell proliferation through multiple mechanisms, including downregulation of CDKN1A and its p21 protein product: this in turn is mediated through direct binding of ETV4 to the CDKN1A promoter and through the ETV4-mediated decrease of p53. This multi-faceted role of ETV4 in prostate cancer makes it a potential target for novel therapeutic approaches that could be explored in this ETV4 transgenic model.

Aluminum exposure promotes histopathological and pro-oxidant damage to the prostate and gonads of male and female adult gerbils.

Since the industrial revolution, all living beings have become susceptible to numerous sources of aluminum (Al) exposure. In addition to causing proven toxicity in many organs and systems, Al can also have estrogenic activity when absorbed by the body. The reproductive organs are commonly affected by environmental pollutants with estrogenic activity, but little is known about the effects of Al on the prostate and gonads. Therefore, the aim of this study was to evaluate the effects of subchronic Al exposure on the prostate and gonads of male and female adult gerbils. After 30 days of oral exposure to aluminum chloride (10 mg/kg/day), the animals were euthanized and the organs processed for cytochemical, ultrastructural, and biochemical assays. Ventral male prostates exposed to Al became hyperplastic and showed signs of cell aging. In addition, the male prostate showed decreased catalase (CAT) and superoxide dismutase (SOD) activity. The female prostate was structurally more affected than the ventral male prostate, since it presented hyperplasia and punctual foci of inflammation and prostatic intraepithelial neoplasia. However, CAT and SOD activities did not change in this gland. In the testis, Al promoted immature germ cell detachment and degeneration, as well as reduced CAT activity. In the ovaries, Al caused reduction in folliculogenesis and decreased SOD activity. Together, these results indicate that Al is toxic to the prostate and gonads of adult gerbils and that continuous exposure to this metal can impair the fertility of individuals of both sexes.

Plasma metabolomic profile in prostatic intraepithelial neoplasia and prostate cancer and associations with the prostate-specific antigen and the Gleason score.

INTRODUCTION: The metabolic alterations reflecting the influence of prostate cancer cells can be captured through metabolomic profiling. OBJECTIVE: To characterize the plasma metabolomic profile in prostatic intraepithelial neoplasia (PIN) and prostate cancer (PCa). METHODS: Metabolomics analyses were performed in plasma samples from individuals classified as non-cancerous control (n = 36), with PIN (n = 16), or PCa (n = 27). Untargeted [26 moieties identified after pre-processing by gas chromatography/mass spectrometry (GC/MS)] and targeted [46 amino acids, carbohydrates, organic acids and fatty acids by GC/MS, and 16 nucleosides and amino acids by ultra performance liquid chromatography-triple quadrupole/mass spectrometry (UPLC-TQ/MS)] analyses were performed. Prostate specific antigen (PSA) concentrations were measured in all samples. In PCa patients, the Gleason scores were determined. RESULTS: The metabolites that were best discriminated (p < 0.05, FDR < 0.2) for the Kruskal-Wallis test with Dunn's post-hoc comparing the control versus the PIN and PCa groups included isoleucine, serine, threonine, cysteine, sarcosine, glyceric acid, among several others. PIN was mainly characterized by alterations on steroidogenesis, glycine and serine metabolism, methionine metabolism and arachidonic acid metabolism, among others. In the case of PCa, the most predominant metabolic alterations were ubiquinone biosynthesis, catecholamine biosynthesis, thyroid hormone synthesis, porphyrin and purine metabolism. In addition, we identified metabolites that were correlated to the PSA [i.e. hypoxanthine (r = - 0.60, p < 0.05; r = - 0.54, p < 0.01) and uridine (r = - 0.58, p < 0.05; r = - 0.50, p < 0.01) in PIN and PCa groups, respectively] and metabolites that were significantly different in PCa patients with Gleason score < 7 and ≥ 7 [i.e. arachidonic acid, median (P25-P75) = 883.0 (619.8-956.4) versus 570.8 (505.6-651.8), respectively (p < 0.01)]. CONCLUSIONS: This human plasma metabolomic assessment contributes to the understanding of the unique metabolic features exhibited in PIN and PCa and provides a list of metabolites that can have the potential to be used as biomarkers for early detection of disease progression and management.

Loss of glutathione peroxidase 3 induces ROS and contributes to prostatic hyperplasia in Nkx3.1 knockout mice.

BACKGROUND: Glutathione peroxidase 3 (Gpx3) protects cells from oxidative stress, and its reduced expression in human prostate cancer has been reported. OBJECTIVES: We hypothesized that Gpx3 might play an important role in the development of prostatic intraepithelial neoplasia (PIN), a pre-cancerous state of the prostate, and aimed to highlight the underlying molecular mechanism. MATERIALS AND METHODS: The following double-knockout mice Nkx3.1-/-; Gpx3+/+, Nkx3.1-/-; Gpx3+/-, Nkx3.1-/-; Gpx3-/- were produced. Randomly divided animals were weighed, and their genitourinary tract (GUT) weights were determined after euthanasia at 4, 8, and 12 months. The mRNA expression of the genes involved in oxidative stress and Wnt signaling was analyzed in the prostate. Histopathology, ROS, and superoxide dismutase (SOD) activities were also measured. RESULTS: Loss of Gpx3 did not affect body weight and GUT weight in Nkx3.1 knockout mice. The mRNA expression of SOD3, iNOS, Hmox, and CISD2, which are associated with oxidative stress, was increased in Nkx3.1-/-; Gpx3-/- mice at 4 months but decreased at 8 and 12 months. There was no change in ß-catenin and its targets associated with Wnt signaling. Increased ROS and decreased SOD activity were observed in Nkx3.1-/-; Gpx3-/- mice at 12 months of age. The histopathologic score and epithelium thickness were increased, and lumen area was decreased in Gpx3 knockout mice. DISCUSSION AND CONCLUSIONS: Gpx3 loss increased the hyperplasia of PIN in the pre-cancerous stage of the prostate. Loss of Gpx3 induced oxidative stress. Histopathologically, no invasive carcinoma was identified, and Gpx3 loss did not increase Wnt/ß-catenin signaling. Further research on the role of GPX3 in the transition of PIN to invasive carcinoma is needed. We show, for the first time, that the antioxidant enzyme GPX3 plays a vital role in inhibiting hyperplasia in the PIN stage of the prostate gland in vivo.

Corpora amylacea in benign prostatic acini are associated with concurrent, predominantly low-grade cancer.

BACKGROUND: Corpora amylacea (CAM), in benign prostatic acini, contain acute-phase proteins. Do CAM coincide with carcinoma? METHODS: Within 270 biopsies, 83 prostatectomies, and 33 transurethral resections (TURs), CAM absence was designated CAM 0; corpora in less than 5% of benign acini: CAM 1; in 5% to 25%: CAM 2; in more than 25%: CAM 3. CAM were compared against carcinoma presence, clinicopathologic findings, and grade groups (GG) 1 to 2 vs 3 to 5. The frequency of CAM according to anatomic zone was counted. A pilot study was conducted using paired initial benign and repeat biopsies (33 benign, 24 carcinoma). RESULTS: A total of 68.9% of biopsies, 96.4% of prostatectomies, and 66.7% of TURs disclosed CAM. CAM ≥1 was common at an older age (P = .019). In biopsies, 204 cases (75%) had carcinoma; and CAM of 2 to 3 (compared to 0-1) were recorded in 25.0% of carcinomas but only 7.4% of benign biopsies (P = .005; odds ratio [OR] = 5.1). CAM correlated with high percent Gleason pattern 3, low GG (P = .035), and chronic inflammation (CI). CI correlated inversely with carcinoma (P = .003). CAM disclosed no association with race, body mass index, serum prostate specific antigen (PSA), acute inflammation (in biopsies), atrophy, or carcinoma volume. With CAM 1, the odds of GG 3 to 5 carcinoma, by comparison to CAM 0, decreased more than 2× (OR = 0.48; P = .032), with CAM 2, more than 3× (OR = 0.33; P = .005), and with CAM 3, almost 3× (OR = 0.39, P = .086). For men aged less than 65, carcinoma predictive model was: Score = (2 × age) + (5 × PSA) - (20 × degree of CAM); using our data, area under the ROC curve was 78.17%. When the transition zone was involved by cancer, it showed more CAM than in cases where it was uninvolved (P = .012); otherwise zonal distributions were similar. In the pilot study, CAM ≥1 predicted carcinoma on repeat biopsy (P < .05; OR = 8), as did CAM 2 to 3 (P < .0001; OR = 30). CI was not significant, and CAM retained significance after adjusting for CI. CONCLUSION: CAM correlate with carcinoma. Whether abundant CAM in benign biopsies adds value amidst high clinical suspicion, warrants further study.

Prostate epithelial-specific expression of activated PI3K drives stromal collagen production and accumulation.

We genetically engineered expression of an activated form of P110 alpha, the catalytic subunit of PI3K, in mouse prostate epithelium to create a mouse model of direct PI3K activation (Pbsn-cre4Prb;PI3KGOF/+ ). We hypothesized that direct activation would cause rapid neoplasia and cancer progression. Pbsn-cre4Prb;PI3KGOF/+ mice developed widespread prostate intraepithelial hyperplasia, but stromal invasion was limited and overall progression was slower than anticipated. However, the model produced profound and progressive stromal remodeling prior to explicit epithelial neoplasia. Increased stromal cellularity and inflammatory infiltrate were evident as early as 4 months of age and progressively increased through 12 months of age, the terminal endpoint of this study. Prostatic collagen density and phosphorylated SMAD2-positive prostatic stromal cells were expansive and accumulated with age, consistent with pro-fibrotic TGF-ß pathway activation. Few reported mouse models accumulate prostate-specific collagen to the degree observed in Pbsn-cre4Prb;PI3KGOF/+ . Our results indicate a signaling process beginning with prostatic epithelial PI3K and TGF-ß signaling that drives prostatic stromal hypertrophy and collagen accumulation. These mice afford a unique opportunity to explore molecular mechanisms of prostatic collagen accumulation that is relevant to cancer progression, metastasis, inflammation and urinary dysfunction. © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Conditional Deletion of Eaf1 Induces Murine Prostatic Intraepithelial Neoplasia in Mice.

ELL-associated factor 1 is a transcription elongation factor that shares significant homology and functional similarity to the androgen-responsive prostate tumor suppressor ELL-associated factor 2. EAF2 is frequently down-regulated in advanced prostate cancer and Eaf2 deletion in the mouse induced the development of murine prostatic intraepithelial neoplasia. Here we show that similar to EAF2, EAF1 is frequently down-regulated in advanced prostate cancer. Co-downregulation of EAF1 and EAF2 occurred in 40% of clinical specimens with Gleason score >7. We developed and characterized a murine model of prostate-epithelial specific deletion of Eaf1 in the prostate and crossed it with our previously generated mouse with conventional deletion of Eaf2. The prostates of Eaf1 deletion mice displayed murine prostatic intraepithelial neoplasia lesions with increased proliferation and inflammation. Combined deletion of Eaf1 and Eaf2 in the murine model induced an increased incidence in mPIN lesions characterized by increased proliferation and CD3+ T cells and CD19+ B cells infiltration compared to individual deletion of either Eaf1 or Eaf2 in the murine prostate. These results suggest that EAF1 may play a tumor suppressive role in the prostate. Cooperation between EAF1 and EAF2 may be important for prostate maintaining prostate epithelial homeostasis, and concurrent loss of these two tumor suppressors may promote prostate tumorigenesis and progression.

Relationship between ETS Transcription Factor ETV1 and TGF-ß-regulated SMAD Proteins in Prostate Cancer.

The ETS transcription factor ETV1 is frequently overexpressed in aggressive prostate cancer, which is one underlying cause of this disease. Accordingly, transgenic mice that prostate-specifically overexpress ETV1 develop prostatic intraepithelial neoplasia. However, progression to the adenocarcinoma stage is stifled in these mice, suggesting that inhibitory pathways possibly preclude ETV1 from exerting its full oncogenic potential. Here we provide evidence that TGF-ß/SMAD signaling represents such an inhibitory pathway. First, we discovered that ETV1 forms complexes with SMAD4. Second, SMAD2, SMAD3 and SMAD4 overexpression impaired ETV1's ability to stimulate gene transcription. Third, TGF-ß1 inhibited ETV1-induced invasion by benign RWPE-1 prostate cells. Fourth, increased expression of SMAD3 and SMAD4 was observable in prostates of ETV1 transgenic mice. Conversely, we found that ETV1 may enhance TGF-ß signaling in PC3 prostate cancer cells, revealing a different facet of the ETV1/TGF-ß interplay. Altogether, these data provide more insights into the regulation and action of ETV1 and additionally suggest that TGF-ß/SMAD signaling exerts its tumor suppressive activity, at least in part, by curtailing the oncogenic potential of ETV1 in prostatic lesions.