Association of High miR-182 Levels with Low-Risk Prostate Cancer.

A subset of men with prostate cancer develops aggressive disease. We sought to determine whether miR-182, an miRNA with reported oncogenic functions in the prostate, is associated with biochemical recurrence and aggressive disease. Prostate epithelial miR-182 expression was quantified via in situ hybridization of two prostate tissue microarrays and by laser-capture microdissection of prostate epithelium. miR-182 was significantly higher in cancer epithelium than adjacent benign epithelium (P < 0.0001). The ratio of cancer to benign miR-182 expression per patient was inversely associated with recurrence in a multivariate logistic regression model (odds ratio = 0.18; 95% CI, 0.03-0.89; P = 0.044). Correlation of miR-182 with mRNA expression in laser-capture microdissected benign prostate epithelium was used to predict prostatic miR-182 targets. Genes that were negatively correlated with miR-182 were enriched for its predicted targets and for genes previously identified as up-regulated in prostate cancer metastases. miR-182 expression was also negatively correlated with genes previously identified as up-regulated in primary prostate tumors from African American patients, who are at an increased risk of developing aggressive prostate cancer. Taken together, these results suggest that although miR-182 is expressed at higher levels in localized prostate cancer, its levels are lower in aggressive cancers, suggesting a biphasic role for this miRNA that may be exploited for prognostic and/or therapeutic purposes to reduce prostate cancer progression.

The Role of RB in Prostate Cancer Progression.

The RB tumor suppressor is one of the most commonly deleted/mutated genes in human cancers. In prostate cancer specifically, mutation of RB is most frequently observed in aggressive, metastatic disease. As one of the earliest tumor suppressors to be identified, the molecular functions of RB that are lost in tumor development have been studied for decades. Earlier work focused on the canonical RB pathway connecting mitogenic signaling to the cell cycle via Cyclin/CDK inactivation of RB, thereby releasing the E2F transcription factors. More in-depth analysis revealed that RB-E2F complexes regulate cellular processes beyond proliferation. Most recently, "non-canonical" roles for RB function have been expanded beyond its E2F interactions, which may play a particular role in advanced prostate cancer. For example, in mouse models of prostate cancer, loss of RB has been shown to induce lineage plasticity, which enables resistance to androgen deprivation therapy. This increased understanding of the potential downstream functions of RB in prostate cancer may lead the way to identifying therapeutic vulnerabilities in cells following RB loss.

Outcomes in Retinal Detachment Repair and Laser Prophylaxis for Syndromes with Optically Empty Vitreous.

PURPOSE: To evaluate and compare surgical outcomes for syndromes with optically empty vitreous (SOEV)-associated rhegmatogenous retinal detachments. DESIGN: A retrospective, cross-sectional, 2-arm study of a single pediatric vitreoretinal surgeon's patients from a quaternary referral center with SOEV was performed to examine visual and anatomical outcomes of rhegmatogenous retinal detachment and laser prophylaxis. SUBJECTS: Patients identified either through slit-lamp examination (presence of an optically empty or void space in the vitreous gel structure) or genetic testing. Fifty-six eyes of 49 patients were identified in the retinal detachment arm. Sixty eyes of 48 patients were identified in the laser prophylaxis arm. METHODS: Comparison of initial retinal detachment (RD) surgical repair via pars plana vitrectomy (PPV), scleral buckle (SB), or PPV-SB with final anatomical success, best-corrected visual acuity (BCVA), and number of surgical procedures. Secondary analysis was performed looking at eyes failing their initial SB, eyes with a giant retinal tear at presentation, eyes failing RD repair within specific time intervals, and eyes where hyaloid was elevated during initial vitrectomy. An additional study arm examined the outcomes of final BCVA and the presence and timing of developing a retinal tear or RD in eyes who received laser prophylaxis. MAIN OUTCOME MEASURES: Visual acuity, surgical repair techniques (PPV, SB, PPV-SB), number of surgeries, anatomical retinal reattachment success. RESULTS: Initial SB had statistically significant better final BCVA (P < 0.01) and better final anatomical success (P < 0.01). No statistical difference in the number of surgeries needed to achieve anatomical success between the initial SB versus initial PPV-SB/PPV. Hyaloidal elevation during the initial vitrectomy was associated with improved final BCVA and higher final anatomical success without the use of silicone oil (P < 0.01 and 0.04 respectively). Lastly, eyes that developed RDs after laser prophylaxis had better final BCVA than untreated eyes (P < 0.05). CONCLUSION: Initial SB yields better overall outcomes in SOEV presenting with rhegmatogenous retinal detachment. Stickler Type-1 patients had similar outcomes compared with other SOEV, suggesting both populations should be treated with similar approaches. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Regulation of Prostate Androgens by Megalin and 25-hydroxyvitamin D Status: Mechanism for High Prostate Androgens in African American Men.

Vitamin D deficiency is associated with an increased risk of prostate cancer mortality and is hypothesized to contribute to prostate cancer aggressiveness and disparities in African American populations. The prostate epithelium was recently shown to express megalin, an endocytic receptor that internalizes circulating globulin-bound hormones, which suggests regulation of intracellular prostate hormone levels. This contrasts with passive diffusion of hormones that is posited by the free hormone hypothesis. Here, we demonstrate that megalin imports testosterone bound to sex hormone-binding globulin into prostate cells. Prostatic loss of Lrp2 (megalin) in a mouse model resulted in reduced prostate testosterone and dihydrotestosterone levels. Megalin expression was regulated and suppressed by 25-hydroxyvitamin D (25D) in cell lines, patient-derived prostate epithelial cells, and prostate tissue explants. In patients, the relationships between hormones support this regulatory mechanism, as prostatic DHT levels are higher in African American men and are inversely correlated with serum 25D status. Megalin levels are reduced in localized prostate cancer by Gleason grade. Our findings suggest that the free hormone hypothesis should be revisited for testosterone and highlight the impact of vitamin D deficiency on prostate androgen levels, which is a known driver of prostate cancer. Thus, we revealed a mechanistic link between vitamin D and prostate cancer disparities observed in African Americans. Significance: These findings link vitamin D deficiency and the megalin protein to increased levels of prostate androgens, which may underpin the disparity in lethal prostate cancer in African America men.

Ocular malignancies treated with iodine-125 low dose rate (LDR) brachytherapy at a single high-volume institution: A retrospective review.

The aim of our study is to document our cases of choroidal melanoma treated with low dose rate (LDR) brachytherapy and to correlate the dosimetry and radiobiology with clinical effects and oncologic outcomes. Data from 157 patients treated from 2014 to 2018 with LDR brachytherapy were used for this investigation. Treatments used a collaborative ocular melanoma study eye plaque and Iodine-125 radioactive seeds. The seeds activities were chosen to deliver 85 Gy to the tumor apex or to a prescription point (if the apex < 5 mm). The plaque sizes used were 10, 12, 14, 16, 18, 20, and 22 mm including notched or deep notched. The plaques were modeled in Varian BrachyVision version 11.6 (Varian Medical Systems) with seed coordinates from the AAPM Task Group 129. The Task Group 43 from AAPM was used for brachytherapy dose planning. Dose data were extracted for the apex, prescription point, sclera, retina opposite to the implant, lens, macula, and optic disc. The radiobiological dosimetry were calculated using appropriate α/ß ratios found in the literature and then correlated to clinical side effects. Average biologically effective dose for associated organs at risk were calculated in cases where toxicity occurred. These included: radiation cataract (70.66 Gy), disc atrophy (475.49 Gy), foveal atrophy (263.07 Gy), radiation papillopathy (373.45 Gy), radiation maculopathy (213.62 Gy), vitreous hemorrhage (1437.68 Gy), vascular occlusion (1080.93 Gy), nonproliferative retinopathy (1066.89 Gy), proliferative retinopathy (1590.71 Gy), exudative retinal detachment (1364.32 Gy), and rhegmatogenous retinal detachment (2265.54 Gy). Average biologically effective dose was higher in patients who developed radiation induced long term side effects than in the whole patient population except for radiation maculopathy. In spite of the small patient population and short-term follow-up, it is of interest to correlate the radiation induced effects and create a guideline for the improvement of the treatment of patients treated with LDR brachytherapy.

Outcomes for posterior uveal melanoma: Validation of American Brachytherapy Society Guidelines.

PURPOSE: To assess outcomes of small and medium choroidal melanoma (less than 5.0 mm in height) following Iodine-125 episcleral brachytherapy. METHODS AND MATERIALS: Patients with small and medium choroidal melanoma that underwent Iodine-125 brachytherapy with apical height of 1.0 mm to 5.0 mm and largest basal diameter of ≤16.0 mm were included. Data were extracted from the original dosimetry plans to determine doses to vision critical structures with the prescription point to the apical height (actual dose, ABS guidelines) and, after simulation, with the prescription point to the height of 5.0 mm (simulated dose, COMS protocol). Visual acuity (VA) outcomes with actual dose and that predicted with the simulated dose were estimated along with local recurrence, ocular survival, and survival at 5 years. RESULTS: A total of 339 patients with a mean age of 61.5 years with a mean follow up duration of 43.4 months were included. The mean dose reduction for lens, optic disc, and fovea was 34%, 39.4%, and 41.4%, respectively with actual dose when compared with simulated dose. The Kaplan-Meier estimations for 3 year event free rate of VA of 20/50 or better were 56% and 31% for actual dose and simulated dose, respectively. Only 3 events of local recurrence were observed (enucleated) yielding 5 year local control and ocular survival rate of 98%. Overall survival (OS) and metastasis free survival (MFS) were 95% and 87.5% at 5 years, respectively. CONCLUSIONS: Small and medium choroidal melanoma treated according to ABS has excellent outcomes. Brachytherapy planning using ABS guidelines as compared to COMS protocol may be associated with lower rates of radiation toxicity and vision loss.

Conditioning of 3D Printed Nanoengineered Ionic-Covalent Entanglement Scaffolds with iP-hMSCs Derived Matrix.

Additive manufacturing is a promising method for producing customized 3D bioactive constructs for regenerative medicine. Here, 3D printed highly osteogenic scaffolds using nanoengineered ionic-covalent entanglement ink (NICE) for bone tissue engineering are reported. This NICE ink consists of ionic-covalent entanglement reinforced with Laponite, a 2D nanosilicate (nSi) clay, allowing for the printing of anatomic-sized constructs with high accuracy. The 3D printed structure is able to maintain high structural stability in physiological conditions without any significant swelling or deswelling. The presence of nSi imparts osteoinductive characteristics to the NICE scaffolds, which is further augmented by depositing pluripotent stem cell-derived extracellular matrix (ECM) on the scaffolds. This is achieved by stimulating human induced pluripotent stem cell-derived mesenchymal stem cells (iP-hMSCs) with 2-chloro-5-nitrobenzanilide, a PPARγ inhibitor that enhances Wnt pathway, resulting in the deposition of an ECM characterized by high levels of collagens VI and XII found in anabolic bone. The osteoinductive characteristics of these bioconditioned NICE (bNICE) scaffolds is demonstrated through osteogenic differentiation of bone marrow derived human mesenchymal stem cells. A significant increase in the expression of osteogenic gene markers as well as mineralized ECM are observed on bioconditioned NICE (bNICE) scaffolds compared to bare scaffolds (NICE). The bioconditioned 3D printed scaffolds provide a unique strategy to design personalized bone grafts for in situ bone regeneration.

Handling and Assessment of Human Primary Prostate Organoid Culture.

This paper describes a detailed protocol for three-dimensional (3D) culturing, handling, and evaluation of human primary prostate organoids. The process involves seeding of epithelial cells sparsely in a 3D matrix gel on a 96-well microplate with media changes to cultivate expansion into organoids. Morphology is then assessed by whole-well capturing of z-stack images. Compression of z-stacks creates a single in-focus image from which organoids are measured to quantify a variety of outputs, including circularity, roundness, and area.DNA, RNA, and protein can be collected from organoids recovered from the matrix gel. Cell populations of interest can be assessed by organoid dissociation and flow cytometry. Formalin-fixation-paraffin-embedding (FFPE) followed by sectioning is used for the histological assessment and antibody staining. Whole-mount immunofluorescent staining preserves organoid morphology and facilitates observation of protein localization in organoids in situ. Commercial assays that are traditionally used for 2D monolayer cells can be modified for 3D organoids. Used together, the techniques in this protocol provide a robust toolbox to quantify prostate organoid growth, morphologic characteristics, and expression of differentiation markers.

Prostate Stroma Increases the Viability and Maintains the Branching Phenotype of Human Prostate Organoids.

The fibromuscular stroma of the prostate regulates normal epithelial differentiation and contributes to carcinogenesis in vivo. We developed and characterized a human 3D prostate organoid co-culture model that incorporates prostate stroma. Primary prostate stromal cells increased organoid formation and directed organoid morphology into a branched acini structure similar to what is observed in vivo. Organoid branching occurred distal to physical contact with stromal cells, demonstrating non-random branching. Stroma-induced phenotypes were similar in all patients examined, yet they maintained inter-patient heterogeneity in the degree of response. Stromal cells expressed growth factors involved in epithelial differentiation, which was not observed in non-prostatic fibroblasts. Organoids derived from areas of prostate cancer maintained differential expression of alpha-methylacyl-CoA racemase and showed increased viability and passaging when co-cultured with stroma. The addition of stroma to epithelial cells in vitro improves the ability of organoids to recapitulate features of the tissue and enhances the viability of organoids.

The miR-183 family cluster alters zinc homeostasis in benign prostate cells, organoids and prostate cancer xenografts.

The miR-183 cluster, which is comprised of paralogous miRs-183, -96 and -182, is overexpressed in many cancers, including prostate adenocarcinoma (PCa). Prior studies showed that overexpression of individual pre-miRs-182, -96 and -183 in prostate cells decreased zinc import, which is a characteristic feature of PCa tumours. Zinc is concentrated in healthy prostate 10-fold higher than any other tissue, and an >80% decrease in zinc is observed in PCa specimens. Here, we studied the effect of overexpression of the entire 4.8 kb miR-183 family cluster, including the intergenic region which contains highly conserved genomic regions, in prostate cells. This resulted in overexpression of mature miR-183 family miRs at levels that mimic cancer-related changes. Overexpression of the miR-183 cluster reduced zinc transporter and intracellular zinc levels in benign prostate cells, PCa xenografts and fresh prostate epithelial organoids. Microarray analysis of miR-183 family cluster overexpression in prostate cells showed an enrichment for cancer-related pathways including adhesion, migration and wound healing. An active secondary transcription start site was identified within the intergenic region of the miR-183 cluster, which may regulate expression of miR-182. Taken together, this study shows that physiologically relevant expression of the miR-183 family regulates zinc levels and carcinogenic pathways in prostate cells.

Prostatic compensation of the vitamin D axis in African American men.

BACKGROUND. African American (AA) men are disproportionately affected by both prostate cancer (PCa) and vitamin D deficiency compared with European American (EA) men. Vitamin D deficiency is linked to increased PCa aggressiveness and mortality. Therefore, it has been hypothesized that vitamin D deficiency may contribute to the PCa disparity between AA and EA men. METHODS. We studied a cross sectional group of 60 PCa patients (AA, n = 31; EA, n = 29) who underwent radical prostatectomy. Vitamin D metabolites 25-hydroxyvitamin D (25(OH)D) and 1,25-dihydroxyvitamin D (1,25(OH)2D) were measured in the serum and tissue by uHPLC-MS-MS. Tissue was laser capture microdissected, and gene expression was quantified by microarray. DNA isolated from whole blood was genotyped for West African ancestry markers and vitamin D-related SNPs. RESULTS. Serum concentrations of 25(OH)D were lower in AAs, but concentrations of 1,25(OH)2D in the prostate tissue were higher compared with EAs. Expression of the vitamin D receptor was higher in prostate tissue from AAs. Expression of the extracellular receptor of vitamin D binding protein, LRP2, was positively associated with West African ancestry and inversely associated with tissue 25(OH)D concentrations in AAs. CONCLUSIONS. The relationships between vitamin D binding protein LRP2 and vitamin D metabolites suggest that the prohormone is actively transported into the prostate, followed by intraprostatic conversion to the active hormone, rather than passive diffusion. These findings support the presence of a compensatory response in prostate tissue to vitamin D deficiency in AAs and reveal a previously unknown complexity involving tissue distribution of vitamin D metabolites. FUNDING. Department of Defense Prostate Cancer Research Program Idea Award for Disparities Research PC121923 (LN and RK) and the NIH 1R01MD007105 (RK).

microRNAs and DICER1 are regulated by 1,25-dihydroxyvitamin D in prostate stroma.

Vitamin D deficiency increases the risk of lethal prostate adenocarcinomas (PCa) and the majority of older men are deficient. Although PCa arises from the epithelium, the surrounding stroma has hormonal regulatory control over the epithelium and contributes to carcinogenesis. Herein, we describe regulation of microRNAs (miRs) by the active hormone dihydroxyvitamin D (1,25(OH)2D) in human prostate stroma. 1,25(OH)2D binds the vitamin D receptor (VDR) transcription factor to regulate gene expression, including miRs, which have emerged as potent regulators of protein expression. 1,25(OH)2D-regulated miRs were identified by profiling in primary human prostatic stromal cells (PrS) and three miRs, miR-126-3p, miR 154-5p and miR-21-5p were subsequently validated in laser-capture micro-dissected prostate stromal tissue from a vitamin D3 clinical trial (N=45). Regulation of these miRs by 1,25(OH)2D was VDR-dependent. Network analysis of known and putative mRNA targets of these miRs was enriched with cancer and inflammation pathways, consistent with known roles of stroma and of vitamin D in carcinogenesis. Expression of the miR processing ribonuclease, DICER1, positively correlated with vitamin D metabolite levels in the clinical trial specimens. High epithelial/stromal ratios of DICER1 were significantly associated biochemical recurrence (OR 3.1, p=0.03) in a tissue microarray of 170 matched PCa patients. In summary, these results underscore the role of the prostate stroma in regulating responses to the hormone 1,25(OH)2D and identified miRs and DICER1 as being regulated in human prostate stroma. Regulation of stromal DICER1 by 1,25(OH)2D may also have clinical relevance in protection against aggressive PCa.

Laser-capture Microdissection of Human Prostatic Epithelium for RNA Analysis.

The prostate gland contains a heterogeneous milieu of stromal, epithelial, neuroendocrine and immune cell types. Healthy prostate is comprised of fibromuscular stroma surrounding discrete epithelial-lined secretory lumens and a very small population of immune and neuroendocrine cells. In contrast, areas of prostate cancer have increased dysplastic luminal epithelium with greatly reduced or absent stromal population. Given the profound difference between stromal and epithelial cell types, it is imperative to separate the cell types for any type of downstream molecular analysis. Despite this knowledge, the bulk of gene expression studies compare benign prostate to cancer without micro-dissection, leading to stromal bias in the benign samples. Laser-capture micro-dissection (LCM) is an effective method to physically separate different cell types from a specimen section. The goal of this protocol is to show that RNA can be successfully isolated from LCM-collected human prostatic epithelium and used for downstream gene expression studies such as RT-qPCR and RNAseq.