Benign Prostate Tissue Research Articles

Human intermediate prostate cancer stem cells contribute to the initiation and development of prostate adenocarcinoma

BackgroundIntermediate cells are present in the early stages of human prostate development and adenocarcinoma. While primary cells isolated from benign human prostate tissues or tumors exhibit an intermediate phenotype in vitro, they cannot form tumors in vivo unless genetically modified. It is unclear about the stem cell properties and tumorigenicity of intermediate cells.MethodsWe developed a customized medium to culture primary human intermediate prostate cells, which were transplanted into male immunodeficient NCG mice to examine tumorigenicity in vivo. We treated the cells with different concentrations of dihydrotestosterone (DHT) and enzalutamide in vitro and surgically castrated the mice after cell transplantation in vivo. Immunostaining, qRT-PCR, RNA sequencing, and western blotting were performed to characterize the cells in tissues and 2D and 3D cultures.ResultsWe found intermediate cells expressing AR+PSA+CK8+CK5+ in the luminal compartment of human prostate adenocarcinoma by immunostaining. We cultured the primary intermediate cells in vitro, which expressed luminal (AR+PSA+CK8+CK18+), basal (CK5+P63+), intermediate (IVL+), and stem cell (CK4+CK13+PSCA+SOX2+) markers. These cells resisted castration in vitro by upregulating the expression of AR, PSA, and proliferation markers KI67 and PCNA. The intermediate cells had high tumorigenicity in vivo, forming tumors in immunodeficient NCG mice in a month without any genetic modification or co-transplantation with embryonic urogenital sinus mesenchyme (UGSM) cells. We named these cells human castration-resistant intermediate prostate cancer stem cells or CriPCSCs and defined the xenograft model as patient primary cell-derived xenograft (PrDX). Human CriPCSCs resisted castration in vitro and in vivo by upregulating AR expression. Furthermore, human CriPCSCs differentiated into amplifying adenocarcinoma cells of luminal phenotype in PrDX tumors in vivo, which can dedifferentiate into CriPCSCs in vitro.ConclusionsOur study identified and established methods for culturing human CriPCSCs, which had high tumorigenicity in vivo without any genetic modification or UGSM co-transplantation. Human CriPCSCs differentiated into amplifying adenocarcinoma cells of luminal phenotype in the fast-growing tumors in vivo, which hold the potential to dedifferentiate into intermediate stem cells. These cells resisted castration by upregulating AR expression. The human CriPCSC and PrDX methods hold significant potential for advancing prostate cancer research and precision medicine.

Dual hyperpolarized [1-13C]pyruvate and [13C]urea magnetic resonance imaging of prostate cancer

BackgroundAlthough multiparametric (mp) 1H magnetic resonance imaging (MRI) is increasingly used to detect and localize prostate cancer (PC), its correlation with tumor grade is limited. Hyperpolarized (HP) carbon-13 (13C) MR is an emerging imaging technique, which can be used to interrogate key biologic processes through in vivo detection of various HP probes. A distinct attribute of HP 13C MRI is the ability to detect multiple HP probes within a single acquisition. Here we report on the first simultaneous dual HP [1-13C]pyruvate and [13C]urea MRI with correlations to histopathologic findings in a patient with localized PC scheduled for radical prostatectomy. Material and methodsPaired HP 13C and standard mp 1H MRI were performed in a patient with biopsy-proven Gleason score 4 + 3 = 7 adenocarcinoma of the prostate scheduled for radical prostatectomy through a first-in-human pilot study of dual-agent HP MRI (NCT02526368). HP 13C MRI was performed using a clinical 3T scanner with 13C transmit-and-receive capabilities. Dynamic series of HP 13C pyruvate, lactate and urea imaging were acquired following intravenous (IV) injection of co-hyperpolarized [13C]urea (25 mM) and [1–13C]pyruvate (125 mM). The [1-13C]pyruvate-to-[1-13C]lactate conversion rate (kPL) was calculated using an inputless two-site exchange model; AUCurea was the [13C]urea signal summed over time. Following radical prostatectomy, whole-mount prostate histopathological slides were prepared and reviewed by an experienced genitourinary pathologist. ResultsFollowing informed consent, the patient underwent paired mp 1H MRI and dual-agent HP MRI. mp 1H MRI revealed a 1.2 cm lesion in the left apical posterior zone. Dual-agent HP MRI identified a focus of increased [1-13C]pyruvate-to-[1-13C]lactate conversion rate (kPL) extending from the left apical posterior peripheral zone to the right gland. A corresponding area of abnormal tissue perfusion (AUCurea) was seen in the left gland. Metabolism-perfusion mismatch (with several foci of increased kPL/AUCurea) was observed throughout the tumor. Tumor extension to the right midgland was confirmed at the time of radical prostatectomy and staining for lactate dehydrogenase-A was increased throughout the tumor relative to surrounding benign prostatic tissue. ConclusionThis first-in-human radiopathologic study demonstrates the feasibility of dual-agent HP MRI in PC patients. Simultaneous assessment of tumor metabolism and perfusion was able to detect occult disease as well as to show a significant mismatch between intra-tumoral metabolism and tissue perfusion in high-grade PC. Prospective validation of these findings is warranted.

A comparative study of histotripsy parameters for the treatment of fibrotic ex-vivo human benign prostatic hyperplasia tissue

Histotripsy is a noninvasive focused ultrasound therapy that mechanically fractionates tissue to create well-defined lesions. In a previous clinical pilot trial to treat benign prostatic hyperplasia (BPH), histotripsy did not result in consistent objective improvements in symptoms, potentially because of the fibrotic and mechanically tough nature of this tissue. In this study, we aimed to identify the dosage required to homogenize BPH tissue by different histotripsy modalities, including boiling histotripsy (BH) and cavitation histotripsy (CH). A method for histotripsy lesion quantification via entropy (HLQE) analysis was developed and utilized to quantify lesion area of the respective treatments. These data were correlated to changes in mechanical stiffness measured by ultrasound shear-wave elastography before and after treatment with each parameter set and dose. Time points corresponding to histologically observed complete lesions were qualitatively evaluated and quantitatively measured. For the BH treatment, complete lesions occurred with > = 30 s treatment time, with a corresponding maximum reduction in stiffness of −90.9 ± 7.2(s.d.)%. High pulse repetition frequency (PRF) CH achieved a similar reduction to that of BH at 288 s (−91.6 ± 6.0(s.d.)%), and low-PRF CH achieved a (−82.1 ± 5.1(s.d.)%) reduction in stiffness at dose > = 144 s. Receiver operating characteristic curve analysis showed that a > ~ 75% reduction in stiffness positively correlated with complete lesions observed histologically, and can provide an alternative metric to track treatment progression.

Establishing and Characterizing the Molecular Profiles, Cellular Features, and Clinical Utility of a Patient-Derived Xenograft Model Using Benign Prostatic Tissues

Benign prostatic hyperplasia (BPH) is a common condition marked by the enlargement of the prostate gland, which often leads to significant urinary symptoms and a decreased quality of life. The development of clinically relevant animal models is crucial for understanding the pathophysiology of BPH and improving treatment options. This study aims to establish a patient-derived xenograft (PDX) model using benign prostatic tissues to explore the molecular and cellular mechanisms of BPH. PDXs were generated by implanting fresh BPH (transition zone) and paired normal (peripheral zone) prostate tissue from 8 patients under the renal capsule of immunodeficient male mice. Tissue weight, architecture, cellular proliferation, apoptosis, prostate-specific marker expression, and molecular profiles of PDXs were assessed after 1 week and 1, 2, or 3 months of implantation by immunohistochemistry, enzyme-linked immunosorbent assay, transcriptomics, and proteomics. Responses to finasteride, a standard-of-care therapy, were evaluated. PDXs maintained histologic and molecular characteristics of the parental human tissues. BPH, but not normal PDXs, demonstrated significant increases in weight and cellular proliferation, particularly at 1 month. Molecular profiling revealed specific gene and protein expression patterns correlating with BPH pathophysiology. Specifically, an increased immune and stress response was observed at 1 week, followed by increased expression of proliferation markers and BPH-specific stromal signaling molecules, such as BMP5 and CXCL13, at 1 month. Graft stabilization to preimplant characteristics was apparent between 2 and 3 months. Treatment with finasteride reduced proliferation, increased apoptosis, and induced morphologic changes consistent with therapeutic responses observed in human BPH. Our PDX model recapitulates the morphologic, histologic, and molecular features of human BPH, offering a significant advancement in modeling the complex interactions of cell types in BPH microenvironments. These PDXs respond to therapeutic intervention as expected, providing a valuable tool for preclinical testing of new therapeutics that will improve the well-being of BPH patients.

Epigenetic profiling of prostate cancer reveals potential prognostic signatures

PurposeWhile epigenetic profiling discovered biomarkers in several tumor entities, its application in prostate cancer is still limited. We explored DNA methylation-based deconvolution of benign and malignant prostate tissue for biomarker discovery and the potential of radiomics as a non-invasive surrogate.MethodsWe retrospectively included 30 patients (63 [58–79] years) with prostate cancer (PCa) who had a multiparametric MRI of the prostate before radical prostatectomy between 2014 and 2019. The control group comprised four patients with benign prostate tissue adjacent to the PCa lesions and four patients with benign prostatic hyperplasia. Tissue punches of all lesions were obtained. DNA methylation analysis and reference-free in silico deconvolution were conducted to retrieve Latent Methylation Components (LCMs). LCM-based clustering was analyzed for cellular composition and correlated with clinical disease parameters. Additionally, PCa and adjacent benign lesions were analyzed using radiomics to predict the epigenetic signatures non-invasively.ResultsLCMs identified two clusters with potential prognostic impact. Cluster one was associated with malignant prostate tissue (p < 0.001) and reduced immune-cell-related signatures (p = 0.004) of CD19 and CD4 cells. Cluster one comprised exclusively malignant prostate tissue enriched for significant prostate cancer and advanced tumor stages (p < 0.03 for both). No radiomics model could non-invasively predict the epigenetic clusters.ConclusionEpigenetic clusters were associated with prognostically and clinically relevant metrics in prostate cancer. Further, immune cell-related signatures differed significantly between prognostically favorable and unfavorable clusters. Further research is necessary to explore potential diagnostic and therapeutic implications.

Prostate Type Malignancies Arising in Ovarian Teratomas - A Report of Two Patients.

The identification of benign prostatic tissue within ovarian and testicular mature teratomas is an unusual occurrence. While a few documented reports exist in the literature regarding the emergence of benign prostatic tissue within teratomas, the occurrence of prostatic-type adenocarcinoma in a mature ovarian teratoma is an exceptionally rare phenomenon. To date, only two prior reports have documented such instances, and no tumors have been previously reported with prostate-type tissue with morphologically two different malignancies. We outline our experience with two tumors involving prostatic-type carcinoma, both arising in ovarian mature teratomas. Microscopic examination of the first tumor revealed small areas of infiltrative atypical glandular proliferation within the mature teratoma. In the second tumor, prostate-type tissue exhibited a low-grade basal cell carcinoma. Additionally, adjacent minute foci of adenocarcinoma of the prostate (Gleason score 3 + 4 = 7, <5% pattern 4) were identified. Goblet cell adenocarcinoma of appendiceal type was also evident in the latter tumor. In both tumors, immunostains (NKX3.1, PSA) were performed to establish the prostatic origin of these atypical glands and PIN4 was performed to document the absence of basal cell in the atypical glands. On clinical follow-up, both patients have no signs of recurrence at 14 and 11 months after the surgery. Further reports on such neoplasms would contribute to a better understanding of the prognosis and management of such occurrences.

A Comparative Study of Histotripsy Parameters for the Treatment of Fibrotic ex-vivo Human Benign Prostatic Hyperplasia Tissue.

Histotripsy is a noninvasive focused ultrasound therapy that mechanically fractionates tissue to create well-defined lesions. In a previous clinical pilot trial to treat benign prostatic hyperplasia (BPH), histotripsy did not result in consistent objective improvements in symptoms, potentially because of the fibrotic and mechanically tough nature of this tissue. In this study, we aimed to identify the dosage required to homogenize BPH tissue by different histotripsy modalities, including boiling histotripsy (BH) and cavitation histotripsy (CH). A method for histotripsy lesion quantification via entropy (HLQE) analysis was developed and utilized to quantify lesion area of the respective treatments. These data were correlated to changes in mechanical stiffness measured by ultrasound shear-wave elastography before and after treatment with each parameter set and dose. Time points corresponding to histologically observed complete lesions were qualitatively evaluated and quantitatively measured. For the BH treatment, complete lesions occurred with >=30s treatment time, with a corresponding maximum reduction in stiffness of -90.9±7.2(s.d.)%. High pulse repetition frequency (PRF) CH achieved a similar reduction to that of BH at 288s (-91.6±6.0(s.d.)%), and low-PRF CH achieved a (-82.1±5.1(s.d.)%) reduction in stiffness at dose >=144s. Receiver operating characteristic curve analysis showed that a >~75% reduction in stiffness positively correlated with complete lesions observed histologically, and can provide an alternative metric to track treatment progression.

HMAGEA2 Accelerates the Progression of Prostate Cancer via the EFNA3-Erk1/2 Signaling Pathway.

Human melanoma-associated antigen A2 (hMAGEA2) family members play several roles in many types of cancer and have been explored as potential prognostic markers. In this study, we investigated the molecular mechanism underlying hMAGEA2-mediated tumorigenesis of prostate cancer. Immunohistochemistry and western blot were used to assess protein expression whereas microarray and quantitative reverse transcription-PCR determined mRNA expression. CCK-8 assay was used to determine cell proliferation. Colony formation assay was used to examine tumorigenesis. Migration and invasion were examined using a transwell assay. Propidium iodide (PI)/Annexin V double staining was performed to measure apoptosis. Transcriptional activity was measured using Dual-luciferase reporter assay. hMAGEA2 was highly over-expressed in human prostate cancer tissues compared to benign prostatic hyperplasia tissues. To elucidate its biological function in prostate cancer, we established two stable hMAGEA2-knockdown prostate cancer cell lines, PC3M and 22RV1, and found that they presented significantly decreased proliferation, anchorage-independent colony formation, migration, and invasion. As hMAGEA2 knockdown suppressed prostate cancer cell growth, we examined its potential influence on tumor apoptosis. hMAGEA2-knockdown cell lines displayed early apoptosis. Moreover, knockdown of hMAGEA2 resulted in the down-regulation of EFNA3 expression. Luciferase assay showed that hMAGEA2 bound to the EFNA promoter region and regulated its transcription. Down-regulation of EFNA3 expression led to decreased Ras/Braf/MEK/Erk1/2 phosphorylation and, consequently, inhibited prostate cancer progression. hMAGEA2 promotes prostate cancer growth, metastasis, and tumorigenesis by regulating the EFNA3-Erk1/2 signaling pathway, indicating its potential as a therapeutic marker for prostate cancer.

Integrative analysis of ultra-deep RNA-seq reveals alternative promoter usage as a mechanism of activating oncogenic programmes during prostate cancer progression.

Transcription factor (TF) proteins regulate gene activity by binding to regulatory regions, most importantly at gene promoters. Many genes have alternative promoters (APs) bound by distinct TFs. The role of differential TF activity at APs during tumour development is poorly understood. Here we show, using deep RNA sequencing in 274 biopsies of benign prostate tissue, localized prostate tumours and metastatic castration-resistant prostate cancer, that AP usage increases as tumours progress and APs are responsible for a disproportionate amount of tumour transcriptional activity. Expression of the androgen receptor (AR), the key driver of prostate tumour activity, is correlated with elevated AP usage. We identified AR, FOXA1 and MYC as potential drivers of AP activation. DNA methylation is a likely mechanism for AP activation during tumour progression and lineage plasticity. Our data suggest that prostate tumours activate APs to magnify the transcriptional impact of tumour drivers, including AR and MYC.

Effective detection of BRAFV595E mutation in canine urothelial and prostate carcinomas using immunohistochemistry.

Canine urothelial carcinoma (UC) and prostate carcinoma (PC) frequently exhibit the BRAFV595E mutation, akin to the BRAFV600E mutation common in various human cancers. Since the initial discovery of the BRAF mutation in canine cancers in 2015, PCR has been the standard method for its detection in both liquid and tissue biopsies. Considering the similarity between the canine BRAFV595E and human BRAFV600E mutations, we hypothesized that immunohistochemistry (IHC) using a BRAFV600E-specific antibody could effectively identify the canine mutant BRAFV595E protein. We tested 122 canine UC (bladder n = 108, urethra n = 14), 21 PC, and benign tissue using IHC and performed digital droplet PCR (ddPCR) on all 122 UC and on 14 IHC positive PC cases. The results from ddPCR and IHC were concordant in 99% (135/136) of the tumours. Using IHC, BRAFV595E was detected in 72/122 (59%) UC and 14/21 (65%) PC. Staining of all benign bladder and prostate tissues was negative. If present, mutant BRAF staining was homogenous, with rare intratumour heterogeneity in three (4%) cases of UC. Additionally, the BRAFV595E mutation was more prevalent in tumours with urothelial morphology, and less common in glandular PC or UC with divergent differentiation. This study establishes that BRAFV600-specific IHC is a reliable and accurate method for detecting the mutant BRAFV595E protein in canine UC and PC. Moreover, the use of IHC, especially with tissue microarrays, provides a cost-efficient test for large-scale screening of canine cancers for the presence of BRAF mutations. This advancement paves the way for further research to define the prognostic and predictive role of this tumour marker in dogs and use IHC to stratify dogs for the treatment with BRAF inhibitors.

Abstract 5863: Double-negative prostate cancer emerges through a mixed basal, club, and hillock cell identity driven by KLF5

Abstract The purpose of this study was to characterize the phenotypes and drivers of therapy-induced lineage plasticity during the development of castration resistant prostate cancer (CRPC). While the majority of localized prostate cancer can be cured with surgery or radiation, metastatic disease is lethal. Therapies targeting the androgen receptor (AR) are initially effective, but eventually men will develop CRPC. About 70-75% of CRPC displays restored AR signaling (ARPC), while the remaining 25-30% display lineage plasticity evidenced by the emergence of AR-negative subtypes including those that display neuroendocrine (NE) markers, or double negative CRPC (DNPC) lacking both AR and NE markers. AR independent manifestations of CRPC represent a clinical challenge because no effective therapies are available and therapeutic targets are largely unknown. We analyzed publicly available bulk and single-cell RNA-seq datasets derived from clinical CRPC specimens to characterize the cellular identity of AR-negative tumors. Using a database of all known transcriptional regulators, we identified potential drivers of these phenotypes. We performed siRNA-mediated knockdown experiments in a model of DNPC to explore the extent to which the candidate regulators maintain AR-negative cell identity and sustain growth of DNPC prostate cancer cells. We identified a subset of CRPC tumors that co-express gene sets defining basal, club, and hillock cells in the benign prostate. This data supports the existence of epithelial cell lineage plasticity manifesting within CRPC tumors, as well as individual CRPC tumor cells, wherein AR-positive tumor cells transform to a phenotype encompassing basal, club, and hillock cell identities. We nominated the stem cell transcription factor KLF5 as a regulator of basal, club, and hillock cell identities in CRPC. In cell line models of DNPC, knock down of KLF5 inhibited cell growth and reduced the expression of genes defining basal, club, and hillock cell identities. This work links a prevalent and poorly-defined subtype of AR-negative CRPC to AR-negative epithelial cell types in benign prostate tissue. Inhibition of KLF5 and its downstream effectors could represent a therapeutic strategy to prevent or delay lineage plasticity and thereby extend patient response to AR-targeted therapies. Citation Format: Samuel Pitzen, Yinjie Qiu, Sarah Munro, Scott Dehm. Double-negative prostate cancer emerges through a mixed basal, club, and hillock cell identity driven by KLF5 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5863.

Abstract 5968: CDC7 is a targetable regulator of advanced prostate cancer

Abstract Prostate cancer is estimated to contribute to over 34,000 deaths in men residing in the United States, with the majority fatality due to metastatic disease. CDC7 is a kinase that regulates DNA replication and is an emerging cancer biomarker for poor prognosis in carcinomas such as Wilms tumor and hepatocellular carcinomas. In this study, we demonstrated that high level of CDC7 is associated with metastatic prostate cancer when compared to benign prostate tissues or localized prostate cancer. Furthermore, we found that CDC7 expression is highest in prostate cancer patient-derived xenografts (PDX) models of adenocarcinomas with neuroendocrine features. In vitro, we showed that inhibition of CDC7 with TAK-931, a CDC7 specific inhibitor, reduced the ability of aggressive prostate cancer cells to proliferate, migrate, and invade. Similarly, knock-down of CDC7 in prostate cancer cell lines inhibited cell growth in a colony formation assay. TAK-931 treated prostate cancer cell lines also showed an abnormal cell cycle profile, indicating that inhibiting CDC7 in aggressive prostate cancer could contribute to replication stress and promote apoptosis. Overall, this study demonstrates that CDC7 is a targetable protein that regulates advanced and aggressive prostate cancer growth. Citation Format: Alifiani Bonita Hartono, Sidharth Paparaju, Chung Lee, Shiqin Liu, Busola R. Alabi, En-Chi Hsu, James D. Brooks, Eva Corey, Tanya Stoyanova. CDC7 is a targetable regulator of advanced prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5968.

AtPCa-Net: anatomical-aware prostate cancer detection network on multi-parametric MRI

Multi-parametric MRI (mpMRI) is widely used for prostate cancer (PCa) diagnosis. Deep learning models show good performance in detecting PCa on mpMRI, but domain-specific PCa-related anatomical information is sometimes overlooked and not fully explored even by state-of-the-art deep learning models, causing potential suboptimal performances in PCa detection. Symmetric-related anatomical information is commonly used when distinguishing PCa lesions from other visually similar but benign prostate tissue. In addition, different combinations of mpMRI findings are used for evaluating the aggressiveness of PCa for abnormal findings allocated in different prostate zones. In this study, we investigate these domain-specific anatomical properties in PCa diagnosis and how we can adopt them into the deep learning framework to improve the model’s detection performance. We propose an anatomical-aware PCa detection Network (AtPCa-Net) for PCa detection on mpMRI. Experiments show that the AtPCa-Net can better utilize the anatomical-related information, and the proposed anatomical-aware designs help improve the overall model performance on both PCa detection and patient-level classification.

3.0-T MR-guided transgluteal in-bore-targeted prostate biopsy under local anesthesia in patients without rectal access: a single-institute experience and review of literature

PurposeTo describe the technique and evaluate the performance of MRI-guided transgluteal in-bore-targeted biopsy of the prostate gland under local anesthesia in patients without rectal access.MethodsTen men (mean age, 69 (range 57–86) years) without rectal access underwent 13 MRI-guided transgluteal in-bore-targeted biopsy of the prostate gland under local anesthesia. All patients underwent mp-MRI at our institute prior to biopsy. Three patients had prior US-guided transperineal biopsy which was unsuccessful in one, negative in one, and yielded GG1 (GS6) PCa in one. Procedure time, complications, histopathology result, and subsequent management were recorded.ResultsMedian interval between rectal surgery and presentation with elevated PSA was 12.5 years (interquartile range (IQR) 25–75, 8–36.5 years). Mean PSA was 11.9 (range, 4.8 -59.0) ng/ml and PSA density was 0.49 (0.05 -3.2) ng/ml/ml. Distribution of PI-RADS v2.0/2.1 scores of the targeted lesions were PI-RADS 5–3; PI-RADS 4–6; and PI-RADS 3–1. Mean lesion size was 1.5 cm (range, 1.0–3.6 cm). Median interval between MRI and biopsy was 5.5 months (IQR 25–75, 1.5–9 months). Mean procedure time was 47.4 min (range, 29–80 min) and the number of cores varied between 3 and 5. Of the 13 biopsies, 4 yielded clinically significant prostate cancer (csPca), with a Gleason score ≥ 7, 1 yielded insignificant prostate cancer (Gleason score = 6), 7 yielded benign prostatic tissue, and one was technically unsuccessful. 3/13 biopsies were repeat biopsies which detected csPCa in 2 out of the 3 patients. None of the patients had biopsy-related complication. Biopsy result changed management to radiation therapy with ADT in 2 patients with the rest on active surveillance.ConclusionMRI-guided transgluteal in-bore-targeted biopsy of the prostate gland under local anesthesia is feasible in patients without rectal access.

The Impact of Inherited Genetic Variation on DNA Methylation in Prostate Cancer and Benign Tissues of African American and European American Men.

American men of African ancestry (AA) have higher prostate cancer incidence and mortality rates compared with American men of European ancestry (EA). Differences in genetic susceptibility mechanisms may contribute to this disparity. To gain insights into the regulatory mechanisms of prostate cancer susceptibility variants, we tested the association between SNPs and DNA methylation (DNAm) at nearby CpG sites across the genome in benign and cancer prostate tissue from 74 AA and 74 EA men. Genome-wide SNP data (from benign tissue) and DNAm were generated using Illumina arrays. Among AA men, we identified 6,298 and 2,641 cis-methylation QTLs (meQTL; FDR of 0.05) in benign and tumor tissue, respectively, with 6,960 and 1,700 detected in EA men. We leveraged genome-wide association study (GWAS) summary statistics to identify previously reported prostate cancer GWAS signals likely to share a common causal variant with a detected meQTL. We identified nine GWAS-meQTL pairs with strong evidence of colocalization (four in EA benign, three in EA tumor, two in AA benign, and three in AA tumor). Among these colocalized GWAS-meQTL pairs, we identified colocalizing expression quantitative trait loci (eQTL) impacting four eGenes with known roles in tumorigenesis. These findings highlight epigenetic regulatory mechanisms by which prostate cancer-risk SNPs can modify local DNAm and/or gene expression in prostate tissue. Overall, our findings showed general consistency in the meQTL landscape of AA and EA men, but meQTLs often differ by tissue type (normal vs. cancer). Ancestry-based linkage disequilibrium differences and lack of AA representation in GWAS decrease statistical power to detect colocalization for some regions.

Transcriptomic analysis of benign prostatic hyperplasia identifies critical pathways in prostatic overgrowth and 5-alpha reductase inhibitor resistance.

The medical therapy of prostatic symptoms (MTOPS) trial randomized men with symptoms of benign prostatic hyperplasia (BPH) and followed response of treatment with a 5α-reductase inhibitor (5ARI), an alpha-adrenergic receptor antagonist (α-blocker), the combination of 5ARI and α-blocker or no medical therapy (none). Medical therapy reduced risk of clinical progression by 66% but the reasons for nonresponse or loss of therapeutic response in some patients remains unresolved. Our previous work showed that prostatic glucocorticoid levels are increased in 5ARI-treated patients and that glucocorticoids can increased branching of prostate epithelia in vitro. To understand the transcriptomic changes associated with 5ARI treatment, we performed bulk RNA sequencing of BPH and control samples from patients who received 5ARI versus those that did not. Deconvolution analysis was performed to estimate cellular composition. Bulk RNA sequencing was also performed on control versus glucocorticoid-treated prostate epithelia in 3D culture to determine underlying transcriptomic changes associated with branching morphogenesis. Surgical BPH (S-BPH) tissue was defined as benign prostatic tissue collected from the transition zone (TZ) of patients who failed medical therapy while control tissue termed Incidental BPH (I-BPH) was obtained from the TZ of men undergoing radical prostatectomy for low-volume/grade prostatic adenocarcinoma confined to the peripheral zone. S-BPH patients were divided into four subgroups: men on no medical therapy (none: n = 7), α-blocker alone (n = 10), 5ARI alone (n = 6) or combination therapy (α-blocker and 5ARI: n = 7). Control I-BPH tissue was from men on no medical therapy (none: n = 8) or on α-blocker (n = 6). A human prostatic cell line in 3D culture that buds and branches was used to identify genes involved in early prostatic growth. Snap-frozen prostatic tissue taken at the time of surgery and 3D organoids were used for RNA-seq analysis. Bulk RNAseq data were deconvoluted using CIBERSORTx. Differentially expressed genes (DEG) that were statistically significant among S-BPH, I-BPH, and during budding and branching of organoids were used for pathway analysis. Transcriptomic analysis between S-BPH (n = 30) and I-BPH (n = 14) using a twofold cutoff (p < 0.05) identified 377 DEG (termed BPH377) and a cutoff < 0.05 identified 3377 DEG (termed BPH3377). Within the S-BPH, the subgroups none and α-blocker were compared to patients on 5ARI to reveal 361 DEG (termed 5ARI361) that were significantly changed. Deconvolution analysis of bulk RNA seq data with a human prostate single cell data set demonstrated increased levels of mast cells, NK cells, interstitial fibroblasts, and prostate luminal cells in S-BPH versus I-BPH. Glucocorticoid (GC)-induced budding and branching of benign prostatic cells in 3D culture was compared to control organoids to identify early events in prostatic morphogenesis. GC induced 369 DEG (termed GC359) in 3D culture. STRING analysis divided the large datasets into 20-80 genes centered around a hub. In general, biological processes induced in BPH supported growth and differentiation such as chromatin modification and DNA repair, transcription, cytoskeleton, mitochondrial electron transport, ubiquitination, protein folding, and cholesterol synthesis. Identified signaling pathways were pooled to create a list of DEG that fell into seven hubs/clusters. The hub gene centrality was used to name the network including AP-1, interleukin (IL)-6, NOTCH1 and NOTCH3, NEO1, IL-13, and HDAC/KDM. All hubs showed connections to inflammation, chromatin structure, and development. The same approach was applied to 5ARI361 giving multiple networks, but the EGF and sonic hedgehog (SHH) hub was of particular interest as a developmental pathway. The BPH3377, 5ARI363, and GC359 lists were compared and 67 significantly changed DEG were identified. Common genes to the 3D culture included an IL-6 hub that connected to genes identified in BPH hubs that defined AP1, IL-6, NOTCH, NEO1, IL-13, and HDAC/KDM. Reduction analysis of BPH and 3D organoid culture uncovered networks previously identified in prostatic development as being reinitiated in BPH. Identification of these pathways provides insight into the failure of medical therapy for BPH and new therapeutic targets for BPH/LUTS.

A Clinically Feasible Electrode Array for 3D Intraoperative Electrical Impedance Tomography-Based Surgical Margin Assessment in Robot-Assisted Radical Prostatectomy.

A novel small form factor circular electrode array was designed specifically for electrical impedance tomography (EIT) based assessment of surgical margins during robot assisted radical prostatectomy (RARP). The electrode array consists of 33 gold-plated electrodes arranged within a 9.5mm diameter circular footprint on the end of a surgical probe that can be introduced through a standard 12mm laparoscopic port used during RARP. The electrode array contains 8 larger, low-contact impedance outer electrodes dedicated for current drive and an internal grid of 25 smaller electrodes for simultaneous voltage measurement. Separating electrode geometry by function is designed to improve current delivery, speed, and resolution while reducing hardware requirements. Simulations demonstrated that 1mm diameter hemispherical prostate cancer inclusions could be localized within regions of adipose and benign prostate tissue; 1.5mm diameter inclusions were required for localization within muscle tissue. A 2.38mm diameter aluminum rod in 0.2 S/m saline could be localized throughout the imaging domain with a position error of less than 2.5mm for depths from the electrode array surface of up to 1.7mm. Ex vivo tissue experiments with a bovine model demonstrate visual congruence of muscle and adipose tissue locations between the sample and reconstructed images. Simulation and experimental results indicate good detection and location of inclusions. These results suggest the proposed electrode array design can provide sufficient accuracy in the detection and localization of prostate cancer against clinically relevant background tissues for use during RARP.

The Mutational and Transcriptional Landscapes of Speckle-Type POZ Protein (SPOP) and Androgen Receptor (AR) in a Single-Center pT3 Prostatectomy Cohort.

Prostate cancer (PCa) is a heterogeneous disease both clinically and genetically. According to The Cancer Genome Atlas (TCGA), the speckle‑type POZ protein (SPOP) mutant form is one of the significant core subtypes of PCa. However, the prognostic value of SPOP variations remains unknown. As a critical PCa driver and an SPOP-targeted protein, androgen receptor (AR) also plays a role in PCa initiation and progression. Thus, we aimed to analyze the mutational status of SPOP and AR with their transcriptional levels in a pathological stage 3 (pT3) prostatectomy cohort consisting of 89 Turkish PCa patients. Targeted sequence analysis and RT-qPCR were performed for SPOP and AR in the benign and malign prostate tissue samples. Our results introduced the two novel pathogenic SPOP variations, C203Y and S236R, in the BTB/POZ domain and a novel pathogenic variant in the ligand-binding domain of AR, R789W. Their predicted pathogenicities and effects on protein features were evaluated by web-based in silico analysis. The overall frequency of SPOP and AR variations for pT3 patients in our population was 3.4% (3/89) and 4.5% (4/89), respectively. The mutational results represented a possible subgroup characterized by carrying the novel variants in SPOP and AR in pT3 PCa patients. In addition to the significant clinicopathological parameters, the mutational results provide a better understanding of the molecular structure of pathologically advanced PCa in the SPOP and AR aspects.

Innervation density and types of nerves in prostate cancer.

Innervation of cancerous tissue represents an important pathway enabling the nervous system to influence the processes associated with the initiation, progression, and metastasis of a neoplastic process. In the context of prostate cancer, several papers report the presence of innervation and its modulating effect on the cancer prognosis. However, most of the data are experimental, with limited information on human prostate cancer innervation. Morphometric analysis of archival prostate specimen immunohistochemistry with neural markers PGP9.5 and S100 showed a significant decrease of nerve density in the prostate cancer (n=44) compared to the normal prostate tissue (n=18) and benign prostatic hyperplasia (n=28). Sympathetic nerves were detected with TH, parasympathetic with VAChT, and sensory nerves with SP and CGRP protein detection. Dual immunofluorescence revealed numerous sympathetic nerves in normal prostate and benign prostatic hyperplasia, especially in the peripheral parts. Only a few parasympathetic nerves were found between the glands and in the peripheral parts of the prostate and benign hyperplasia. Sporadic positivity for sensory innervation was present only in approximately 1/10 of nerve fibers, especially in the larger nerves. The pattern of innervation in prostate cancer was analogous to that in normal prostate gland and benign prostatic hyperplasia but there was a significantly lower amount of all nerve types, especially in high-grade carcinoma cases. Although not significant, there was a tendency of decreasing innervation density with increasing Gleason score. Regarding the low density of nerves in prostate carcinoma, the significantly lower PCNA counts in nerves of the cancer specimens cannot be ascribed to lower proliferation activity. Our data confirmed the lower nerve density in the prostate cancer compared to the benign prostate tissue. We could not approve an increased nerve proliferation activity in prostate cancer. All nerve types, most the sympathetic, less the parasympathetic, and the sensory nerves, are present in prostate cancer. The highest nerve density at the periphery of the cancer tissue implies this to be the result of an expansive tumor growth. It is evident that the results of experimental prostate cancer models can be applied to human pathology only to a certain extent. The relation between the range of innervation and the biology of prostate cancer is very complex and will require more detailed information to be applied in therapeutic solutions.

PiRNA-4447944 promotes castration-resistant growth and metastasis of prostate cancer by inhibiting NEFH expression through forming the piRNA-4447944-PIWIL2-NEFH complex.

Castration-resistant prostate cancer (CRPC) is the leading cause of prostate cancer (PCa)-related death in males, which occurs after the failure of androgen deprivation therapy (ADT). PIWI-interacting RNAs (piRNAs) are crucial regulators in many human cancers, but their expression patterns and roles in CRPC remain unknown. In this study, we performed small RNA sequencing to explore CRPC-associated piRNAs using 10 benign prostate tissues, and 9 paired hormone-sensitive PCa (HSPCa) and CRPC tissues from the same patients. PiRNA-4447944 (piR-4447944) was discovered to be highly expressed in CRPC group compared with HSPCa and benign groups. Functional analyses revealed that piR-4447944 overexpression endowed PCa cells with castration resistance ability in vitro and in vivo, whereas knockdown of piR-4447944 using anti-sense RNA suppressed the proliferation, migration and invasion of CRPC cells. Additionally, enforced piR-4447944 expression promoted in vitro migration and invasion of PCa cells, and reduced cell apoptosis. Mechanistically, piR-4447944 bound to PIWIL2 to form a piR-4447944/PIWIL2 complex and inhibited tumor suppressor NEFH through direct interaction at the post-transcriptional level. Collectively, our study indicates that piR-4447944 is essential for prostate tumor-propagating cells and mediates androgen-independent growth of PCa, which extends current understanding of piRNAs in cancer biology and provides a potential approach for CRPC treatment.