Using CT-guided stereotactic prostate radiation therapy (CT-SPRT) to assess sustained murine prostate ablation

The prostate is a hormone-responsive organ where testicular androgens drive the proliferation and survival of prostatic cells, ensuring the development and functioning of this gland throughout life. Androgen deprivation therapy leads to apoptosis of prostatic cells and organ regression, and is a cornerstone of prostate cancer and benign prostatic hypertrophy treatment. For several decades, androgen deprivation has been used as an adjuvant to external beam radiotherapy, however, emerging data suggests that the low rates of epithelial proliferation in the castrated prostate imparts radio-resistance. As proliferating cells exhibit increased sensitivity to radiation, we hypothesized that short bursts of synchronized epithelial proliferation, which can be achieved by exogeneous testosterone supplementation prior to targeted high-dose radiation, would maximize sustained prostate ablation, while minimizing damage to surrounding tissues. To test this hypothesis, we designed a novel computed-tomography (CT)-guided stereotactic prostate radiation therapy (CT-SPRT) technique to deliver a single high-dose 25 Gy fraction of X-ray radiation. Sustained prostatic cell ablation was assessed post CT-SPRT by measuring prostate weight, epithelial cell number, and relative contributions of luminal and basal epithelial populations in control and testosterone-pretreated glands. CT-SPRT was safely delivered with no observed damage to surrounding rectal and bladder tissues. Importantly, castrated mice that received a pulse of testosterone to induce synchronous cell proliferation prior to CT-SPRT exhibited significant sustained gland ablation compared to control mice. These results provide new insights in stereotactic radiotherapy sensitivity to maximize prostatic cell ablation and improve our understanding of prostate gland regeneration that can potentially lead to improved non-invasive therapies for benign prostatic hypertrophy and prostate cancer.

Cordyceps militaris Fruit Body Extract Decreases Testosterone Catabolism and Testosterone-Stimulated Prostate Hypertrophy

The androgens testosterone and dihydrotestosterone (DHT) are essential for a variety of systemic functions in mature males. Alteration of these hormones results in late-onset hypogonadism (LOH) and benign prostate hyperplasia (BPH). The fruit bodies of fungi of the genus Cordyceps have been regarded as folk medicine or health food with tonic and antifatigue effects. The extract from the fruit body of Cordyceps militaris parasitizing Samia cynthia ricini (CM) was evaluated as a novel-candidate natural product for ameliorating male andropause symptoms. To explore the effects of CM on LOH and BPH, CM was applied to rat models and cultured testicular cells and prostate cells. The concentrations of androgens in the serum and culture media were determined by ELISA. Expression of steroidogenic enzymes and androgen-related genes was evaluated by qPCR, and prostatic cell proliferation was assessed with the cell-viability assay. CM maintained the serum levels of testosterone and DHT, but inhibited testosterone-induced prostate hypertrophy. CM also increased the secretion of testosterone and DHT by primary testicular cells, with no changes in the mRNA expression of steroidogenic enzymes, but decreased the growth of prostatic cell lines. Our data suggest that CM could improve both LOH and BPH in males.

An immunohistochemical prostate cell identification key indicates that aging shifts procollagen 1A1 production from myofibroblasts to fibroblasts in dogs prone to prostate-related urinary dysfunction

BackgroundThe identity and spatial distribution of prostatic cell types has been determined in humans but not in dogs, even though aging- and prostate-related voiding disorders are common in both species and mechanistic factors, such as prostatic collagen accumulation, appear to be shared between species. In this publication we characterize the regional distribution of prostatic cell types in the young intact dog to enable comparisons with human and mice and we examine how the cellular source of procollagen 1A1 changes with age in intact male dogs.MethodsA multichotomous decision tree involving sequential immunohistochemical stains was validated for use in dog and used to identify specific prostatic cell types and determine their distribution in the capsule, peripheral, periurethral and urethral regions of the young intact canine prostate. Prostatic cells identified using this technique include perivascular smooth muscle cells, pericytes, endothelial cells, luminal, intermediate, and basal epithelial cells, neuroendocrine cells, myofibroblasts, fibroblasts, fibrocytes, and other hematolymphoid cells. Corresponding images were made freely accessible through the GUDMAP database at https://doi.org/10.25548/16-WMM4.ResultsThe prostatic peripheral region harbors the largest proportion of epithelial cells. Aging does not change the density of hematolymphoid cells, fibroblasts, and myofibroblasts in the peripheral region or in the fibromuscular capsule, regions where we previously observed aging- and androgen-mediated increases in prostatic collagen abundance Instead, we observed aging-related changes the procollagen 1A1 positive prostatic cell identity from a myofibroblast to a fibroblast.ConclusionsHematolymphoid cells and myofibroblasts are often identified as sources of collagen in tissues prone to aging-related fibrosis. We show that these are not the likely sources of pathological collagen synthesis in older intact male dogs. Instead, we identify an aging-related shift in the prostatic cell type producing procollagen 1A1 that will help direct development of cell type and prostate appropriate therapeutics for collagen accumulation.

New Insights into the Role of Polybromo-1 in Prostate Cancer

The human protein Polybromo-1 (PBMR1/BAF180) is a component of the SWI/SNF chromatin-remodeling complex that has been reported to be deregulated in tumors. However, its role in prostate cancer (PCa) is largely unknown. In this study, we described the PBRM1 transcriptional levels and the protein expression/localization in tissues of PCa patients and in prostatic cell lines. Increased PBRM1 mRNA levels were found in PCa samples, when compared to benign disease, and were correlated with higher Gleason score. We also verified that only the nuclear localization of PBRM1 protein is correlated with a more aggressive disease and high Prostate-Specific Antigen (PSA) levels in tissue microarrays. Intriguing expression patterns of mRNA and protein were identified in the cell lines. Although PBRM1 protein was restricted to the nuclei, in tumor cell lines in non-neoplastic cells, it was also present in vesicular-like structures that were dispersed within the cytoplasm. We knocked-down PBRM1 in the castration-resistant PCa (CRPC) cell line PC-3 and we verified that PBRM1 promotes the expression of several markers of aggressiveness, including EpCAM, TGF-β, and N-Cadherin. Therefore, our data supported the hypothesis that PBRM1 displays a pivotal role in the promotion and maintenance of the malignant behavior of PCa, especially in CRPC.

Assessment of Global Methylation in Paraffin Embedded Prostatic Tissues and Cell Lines Using Flow Cytometry

Background. The aim of this study is to measure global 5-methylcystosine (5MeC) methylation in paraffin embedded prostatic tissues and cell lines using flow cytometry. Methods. Cell/nuclei suspension from 10 cases of benign prostatic hyperplasia (BPH), 10 cases of prostatic adenocarcinoma, and two prostatic cell lines (PNT1A and LNCaP) were prepared using modified heat pretreatment technique. 5MeC global methylation was assessed by flow cytometry of cell/nuclei suspension and immunostaining of tissue sections. Results. Higher percentage of positively stained cells (PPSC) and mean channel fluorescence (MCF) were detected in PNT1A cell line and BPH cell/nuclei suspensions as compared to LNCaP cell lines and adenocarcinoma cell/nuclei suspensions. Lower scores of 5MeC immunostaining were observed in all prostate adenocarcinoma tissue sections as compared to BPH sections indicating global hypomethylation in prostate adenocarcinoma. Two distinctive populations of cells were detected in histograms generated from most of the BPH cell/nuclei suspensions. Conclusion. The study developed a novel technique that could measure 5MeC global methylation in paraffin embedded prostatic tissues. This represents a rapid and objective assessment of methylation and when combined with tissue micro-dissection and cell sorting, this technique could be applied to larger tissue samples such as post radical prostatectomy and transurethral resected specimens.