p63 is a prostate basal cell marker and is required for prostate development

Digital analysis of the prostate tumor microenvironment with high-order chromogenic multiplexing

As our understanding of the tumor microenvironment grows, the pathology field is increasingly utilizing multianalyte diagnostic assays to understand important characteristics of tumor growth. In clinical settings, brightfield chromogenic assays represent the gold-standard and have developed significant trust as the first-line diagnostic method. However, conventional brightfield tests have been limited to low-order assays that are visually interrogated. We have developed a hybrid method of brightfield chromogenic multiplexing that overcomes these limitations and enables high-order multiplex assays. However, how compatible high-order brightfield multiplexed images are with advanced analytical algorithms has not been extensively evaluated. In the present study, we address this gap by developing a novel 6-marker prostate cancer assay that targets diverse aspects of the tumor microenvironment such as prostate-specific biomarkers (PSMA and p504s), immune biomarkers (CD8 and PD-L1), a prognostic biomarker (Ki-67), as well as an adjunctive diagnostic biomarker (basal cell cocktail) and apply the assay to 143 differentially graded adenocarcinoma prostate tissues. The tissues were then imaged on our spectroscopic multiplexing imaging platform and mined for proteomic and spatial features that were correlated with cancer presence and disease grade. Extracted features were used to train a UMAP model that differentiated healthy from cancerous tissue with an accuracy of 89% and identified clusters of cells based on cancer grade. For spatial analysis, cell-to-cell distances were calculated for all biomarkers and differences between healthy and adenocarcinoma tissues were studied. We report that p504s positive cells were at least 2× closer to cells expressing PD-L1, CD8, Ki-67, and basal cell in adenocarcinoma tissues relative to the healthy control tissues. These findings offer a powerful insight to understand the fingerprint of the prostate tumor microenvironment and indicate that high-order chromogenic multiplexing is compatible with digital analysis. Thus, the presented chromogenic multiplexing system combines the clinical applicability of brightfield assays with the emerging diagnostic power of high-order multiplexing in a digital pathology friendly format that is well-suited for translational studies to better understand mechanisms of tumor development and growth.

Bioinformatics in urology - molecular characterization of pathophysiology and response to treatment

The application of bioinformatics has revolutionized the practice of medicine in the past 20 years. From early studies that uncovered subtypes of cancer to broad efforts spearheaded by the Cancer Genome Atlas initiative, the use of bioinformatics strategies to analyse high-dimensional data has provided unprecedented insights into the molecular basis of disease. In addition to the identification of disease subtypes - which enables risk stratification - informatics analysis has facilitated the identification of novel risk factors and drivers of disease, biomarkers of progression and treatment response, as well as possibilities for drug repurposing or repositioning; moreover, bioinformatics has guided research towards precision and personalized medicine. Implementation of specific computational approaches such as artificial intelligence, machine learning and molecular subtyping has yet to become widespread in urology clinical practice for reasons of cost, disruption of clinical workflow and need for prospective validation of informatics approaches in independent patient cohorts. Solving these challenges might accelerate routine integration of bioinformatics into clinical settings.

Prostate lineage-specific metabolism governs luminal differentiation and response to antiandrogen treatment

Lineage transitions are a central feature of prostate development, tumourigenesis and treatment resistance. While epigenetic changes are well known to drive prostate lineage transitions, it remains unclear how upstream metabolic signalling contributes to the regulation of prostate epithelial identity. To fill this gap, we developed an approach to perform metabolomics on primary prostate epithelial cells. Using this approach, we discovered that the basal and luminal cells of the prostate exhibit distinct metabolomes and nutrient utilization patterns. Furthermore, basal-to-luminal differentiation is accompanied by increased pyruvate oxidation. We establish the mitochondrial pyruvate carrier and subsequent lactate accumulation as regulators of prostate luminal identity. Inhibition of the mitochondrial pyruvate carrier or supplementation with exogenous lactate results in large-scale chromatin remodelling, influencing both lineage-specific transcription factors and response to antiandrogen treatment. These results establish reciprocal regulation of metabolism and prostate epithelial lineage identity.

Therapeutic, diagnostic and prognostic values of TRIM proteins in prostate cancer

Prostate cancer is the second most prevalent cancer in men worldwide. The TRIM (tripartite motif) family of proteins is involved in the regulation of various cellular processes, including antiviral immunity, apoptosis, and cancer progression. In recent years, several TRIM proteins have been found to play important roles in prostate cancer initiation and progression. TRIM proteins have indicated oncogenic activity in prostate cancer by enhancing androgen or estrogen receptor signaling and promoting cancer cell growth. Inhibition of TRIM proteins has been raised as a potential therapeutic strategy for the treatment of prostate cancer. Overall, these studies suggest that TRIM family proteins exert tumor-promoting effects in prostate cancer, and targeting these proteins can provide a promising therapeutic strategy for prostate cancer treatment. On the other hand, some TRIM proteins can be differentially expressed in prostate cancer cells compared to normal cells, thus providing novel diagnostic/prognostic biomarkers for prostate cancer.

p63: a crucial player in epithelial stemness regulation

Epithelial tissue homeostasis is closely associated with the self-renewal and differentiation behaviors of epithelial stem cells (ESCs). p63, a well-known marker of ESCs, is an indispensable factor for their biological activities during epithelial development. The diversity of p63 isoforms expressed in distinct tissues allows this transcription factor to have a wide array of effects. p63 coordinates the transcription of genes involved in cell survival, stem cell self-renewal, migration, differentiation, and epithelial-to-mesenchymal transition. Through the regulation of these biological processes, p63 contributes to, not only normal epithelial development, but also epithelium-derived cancer pathogenesis. In this review, we provide an overview of the role of p63 in epithelial stemness regulation, including self-renewal, differentiation, proliferation, and senescence. We describe the differential expression of TAp63 and ΔNp63 isoforms and their distinct functional activities in normal epithelial tissues and in epithelium-derived tumors. Furthermore, we summarize the signaling cascades modulating the TAp63 and ΔNp63 isoforms as well as their downstream pathways in stemness regulation.

Basal epithelial cells in prostate development, tumorigenesis, and cancer progression

The prostate epithelium is composed of two predominant cell populations: luminal and basal epithelial cells. Luminal cells have a secretory function that supports male fertility while basal cells function in regeneration and maintenance of epithelial tissue. Recent studies in humans and mice have expanded our knowledge of the role and regulation of luminal and basal cells in prostate organogenesis, development, and homeostasis. The insights from healthy prostate biology can inform studies focused on the origins of prostate cancer, progression of the disease, and development of resistance to targeted hormonal therapies. In this review, we discuss a critical role for basal cells in the development and maintenance of healthy prostate tissue. Additionally, we provide evidence supporting a role for basal cells in oncogenesis and therapeutic resistance mechanisms of prostate cancer. Finally, we describe basal cell regulators that may promote lineage plasticity and basal cell identity in prostate cancers that have developed therapeutic resistance. These regulators could serve as therapeutic targets to inhibit or delay resistance and thereby improve outcomes for prostate cancer patients.

Novel Histopathological Biomarkers in Prostate Cancer: Implications and Perspectives

Prostate cancer (PCa) is the second most frequently diagnosed cancer in men. Despite the significant progress in cancer diagnosis and treatment over the last few years, the approach to disease detection and therapy still does not include histopathological biomarkers. The dissemination of PCa is strictly related to the creation of a premetastatic niche, which can be detected by altered levels of specific biomarkers. To date, the risk factors for biochemical recurrence include lymph node status, prostate-specific antigen (PSA), PSA density (PSAD), body mass index (BMI), pathological Gleason score, seminal vesicle invasion, extraprostatic extension, and intraductal carcinoma. In the future, biomarkers might represent another prognostic factor, as discussed in many studies. In this review, we focus on histopathological biomarkers (particularly CD169 macrophages, neuropilin-1, cofilin-1, interleukin-17, signal transducer and activator of transcription protein 3 (STAT3), LIM domain kinase 1 (LIMK1), CD15, AMACR, prostate-specific membrane antigen (PSMA), Appl1, Sortilin, Syndecan-1, and p63) and their potential application in decision making regarding the prognosis and treatment of PCa patients. We refer to studies that found a correlation between the levels of biomarkers and tumor characteristics as well as clinical outcomes. We also hypothesize about the potential use of histopathological markers as a target for novel immunotherapeutic drugs or targeted radionuclide therapy, which may be used as adjuvant therapy in the future.

Cancer stem cell in prostate cancer progression, metastasis and therapy resistance

Prostate cancer (PCa) is the most diagnosed malignancy in the men worldwide. Cancer stem cells (CSCs) are the sub-population of cells present in the tumor which possess unique properties of self-renewal and multilineage differentiation thus thought to be major cause of therapy resistance, disease relapse, and mortality in several malignancies including PCa. CSCs have also been shown positive for the common stem cells markers such as ALDH EZH2, OCT4, SOX2, c-MYC, Nanog etc. Therefore, isolation and characterization of CSCs specific markers which may discriminate CSCs and normal stem cells are critical to selectively eliminate CSCs. Rapid advances in the field offers a theoretical explanation for many of the enduring uncertainties encompassing the etiology and an optimism for the identification of new stem-cell targets, development of reliable and efficient therapies in the future. The emerging reports have also provided unprecedented insights into CSCs plasticity, quiescence, renewal, and therapeutic response. In this review, we discuss the identification of PCa stem cells, their unique properties, stemness-driving pathways, new diagnostics, and therapeutic interventions.

Seasonal changes of the prostate gland in the raccoon (Procyon lotor) inhabiting Hokkaido, Japan

In the prostate gland of the raccoon (Procyon lotor), the morphological appearance of the epithelial cells, such as basal and luminal cells, and the expressions of p63, androgen receptor (AR), and proliferating cell nuclear antigen (PCNA) were examined histologically and immunohistochemically to clarify their seasonal dynamics throughout the year. In this study, the regression with luminal cell defluxion and the regeneration process of the prostatic glandular epithelium was revealed in the seasons with declined spermatogenesis (June to August). The expression of p63 was observed only in the basal cells. AR immunoreactivity in the luminal cells was shown in the developed and regenerating (close to developed) prostates, whereas the basal cells exhibited AR immunoreactivity all year round. PCNA expression was rare in epithelial cells of the developed prostate gland. In the regressed gland, the basal cells demonstrated proliferative ability, whereas PCNA of the luminal cells appeared for the first time in the regenerating phase. This study is the first to clarify the regression with luminal cell defluxion and restoration and the seasonal dynamics of AR expression and proliferative activity in the prostate gland of seasonal breeders.

Single-cell atlas of epithelial and stromal cell heterogeneity by lobe and strain in the mouse prostate

BACKGROUND

Evaluating the complex interplay of cell types in the tissue microenvironment is critical to understanding the origin and progression of diseases in the prostate and potential opportunities for intervention. Mouse models are an essential tool to investigate the molecular and cell-type-specific contributions of prostate disease at an organismal level. While there are well-documented differences in the extent, timing, and nature of disease development in various genetically engineered and exposure-based mouse models in different mouse strains and prostate lobes within each mouse strain, the underlying molecular phenotypic differences in cell types across mouse strains and prostate lobes are incompletely understood.

METHODS

In this study, we used single-cell RNA-sequencing (scRNA-seq) methods to assess the single-cell transcriptomes of 6-month-old mouse prostates from two commonly used mouse strains, friend virus B/NIH jackson (FVB/NJ) (N = 2) and C57BL/6J (N = 3). For each mouse, the lobes of the prostate were dissected (anterior, dorsal, lateral, and ventral), and individual scRNA-seq libraries were generated. In situ and pathological analyses were used to explore the spatial and anatomical distributions of novel cell types and molecular markers defining these cell types.

RESULTS

Data dimensionality reduction and clustering analysis of scRNA-seq data revealed that basal and luminal cells possessed strain-specific transcriptomic differences, with luminal cells also displaying marked lobe-specific differences. Gene set enrichment analysis comparing luminal cells by strain showed enrichment of proto-Oncogene targets in FVB/NJ mice. Additionally, three rare populations of epithelial cells clustered independently of strain and lobe: one population of luminal cells expressing Foxi1 and components of the vacuolar ATPase proton pump (Atp6v0d2 and Atp6v1g3), another population expressing Psca and other stem cell-associated genes (Ly6a/Sca-1, Tacstd2/Trop-2), and a neuroendocrine population expressing Chga, Chgb, and Syp. In contrast, stromal cell clusters, including fibroblasts, smooth muscle cells, endothelial cells, pericytes, and immune cell types, were conserved across strain and lobe, clustering largely by cell type and not by strain or lobe. One notable exception to this was the identification of two distinct fibroblast populations that we term subglandular fibroblasts and interstitial fibroblasts based on their strikingly distinct spatial distribution in the mouse prostate.

CONCLUSIONS

Altogether, these data provide a practical reference of the transcriptional profiles of mouse prostate from two commonly used mouse strains and across all four prostate lobes.

Novel biomarkers predict prognosis and drug-induced neuroendocrine differentiation in patients with prostate cancer

Background

A huge focus is being placed on the development of novel signatures in the form of new combinatorial regimens to distinguish the neuroendocrine (NE) characteristics from castration resistant prostate cancer (CRPC) timely and accurately, as well as predict the disease-free survival (DFS) and progression-free survival (PFS) of prostate cancer (PCa) patients.

Methods

Single cell data of 4 normal samples, 3 CRPC samples and 3 CRPC-NE samples were obtained from GEO database, and CellChatDB was used for potential intercellular communication, Secondly, using the "limma" package (v3.52.0), we obtained the differential expressed genes between CRPC and CRPC-NE both in single-cell RNA seq and bulk RNA seq samples, and discovered 12 differential genes characterized by CRPC-NE. Then, on the one hand, the diagnosis model of CRPC-NE is developed by random forest algorithm and artificial neural network (ANN) through Cbioportal database; On the other hand, using the data in Cbioportal and GEO database, the DFS and PFS prognostic model of PCa was established and verified through univariate Cox analysis, least absolute shrinkage and selection operator (Lasso) regression and multivariate Cox regression in R software. Finally, somatic mutation and immune infiltration were also discussed.

Results

Our research shows that there exists specific intercellular communication in classified clusters. Secondly, a CRPC-NE diagnostic model of six genes (HMGN2, MLLT11, SOX4, PCSK1N, RGS16 and PTMA) has been established and verified, the area under the ROC curve (AUC) is as high as 0.952 (95% CI: 0.882-0.994). The mutation landscape shows that these six genes are rarely mutated in the CRPC and NEPC samples. In addition, NE-DFS signature (STMN1 and PCSK1N) and NE-PFS signature (STMN1, UBE2S and HMGN2) are good predictors of DFS and PFS in PCa patients and better than other clinical features. Lastly, the infiltration levels of plasma cells, T cells CD4 naive, Eosinophils and Monocytes were significantly different between the CRPC and NEPC groups.

Conclusions

This study revealed the heterogeneity between CRPC and CRPC-NE from different perspectives, and developed a reliable diagnostic model of CRPC-NE and robust prognostic models for PCa.

ΔNp63 drives dysplastic alveolar remodeling and restricts epithelial plasticity upon severe lung injury

The lung exhibits a robust, multifaceted regenerative response to severe injuries such as influenza infection, during which quiescent lung-resident epithelial progenitors participate in two distinct reparative pathways: functionally beneficial regeneration via alveolar type 2 (AT2) cell proliferation and differentiation, and dysplastic tissue remodeling via intrapulmonary airway-resident basal p63+ progenitors. Here we show that the basal cell transcription factor ΔNp63 is required for intrapulmonary basal progenitors to participate in dysplastic alveolar remodeling following injury. We find that ΔNp63 restricts the plasticity of intrapulmonary basal progenitors by maintaining either active or repressive histone modifications at key differentiation gene loci. Following loss of ΔNp63, intrapulmonary basal progenitors are capable of either airway or alveolar differentiation depending on their surrounding environment both in vitro and in vivo. Uncovering these regulatory mechanisms of dysplastic repair and lung basal cell fate choice highlight potential therapeutic targets to promote functional alveolar regeneration following severe lung injuries.

Stem Cells as Target for Prostate cancer Therapy: Opportunities and Challenges

Cancer stem cells (CSCs) and cells in a cancer stem cell-like (CSCL) state have proven to be responsible for tumor initiation, growth, and relapse in Prostate Cancer (PCa) and other cancers; therefore, new strategies are being developed to target such cellular populations. TLR3 activation-based immunotherapy using Polyinosinic:Polycytidylic acid (PIC) has been proposed to be used as a concomitant strategy to first-line treatment. This strategy is based on the induction of apoptosis and an inflammatory response in tumor cells. In combination with retinoids like 9cRA, this treatment can induce CSCs differentiation and apoptosis. A limitation in the use of this combination is the common decreased expression of TLR3 and its main positive regulator p53. observed in many patients suffering of different cancer types such as PCa. Importantly, human exposure to certain toxicants, such as iAs, not only has proven to enrich CSCs population in an in vitro model of human epithelial prostate cells, but additionally, it can also lead to a decreased p53, TLR3 and RA receptor (RARβ), expression/activation and thus hinder this treatment efficacy. Therefore, here we point out the relevance of evaluating the TLR3 and P53 status in PCa patients before starting an immunotherapy based on the use of PIC +9cRA to determine whether they will be responsive to treatment. Additionally, the use of strategies to overcome the lower TLR3, RARβ or p53 expression in PCa patients, like the inclusion of drugs that increase p53 expression, is encouraged, to potentiate the use of PIC+RA based immunotherapy in these patients.

The mTOR chromatin-bound interactome in prostate cancer

A growing number of studies support a direct role for nuclear mTOR in gene regulation and chromatin structure. Still, the scarcity of known chromatin-bound mTOR partners limits our understanding of how nuclear mTOR controls transcription. Herein, comprehensive mapping of the mTOR chromatin-bound interactome in both androgen-dependent and -independent cellular models of prostate cancer (PCa) identifies a conserved 67-protein interaction network enriched for chromatin modifiers, transcription factors, and SUMOylation machinery. SUMO2/3 and nuclear pore protein NUP210 are among the strongest interactors, while the androgen receptor (AR) is the dominant androgen-inducible mTOR partner. Further investigation reveals that NUP210 facilitates mTOR nuclear trafficking, that mTOR and AR form a functional transcriptional module with the nucleosome remodeling and deacetylase (NuRD) complex, and that androgens specify mTOR-SUMO2/3 promoter-enhancer association. This work identifies a vast network of mTOR-associated nuclear complexes advocating innovative molecular strategies to modulate mTOR-dependent gene regulation with conceivable implications for PCa and other diseases.

Molecular Markers in Urinary Bladder Cancer: Applications for Diagnosis, Prognosis and Therapy

Cancer of the urinary bladder is a neoplasm with considerable importance in veterinary medicine, given its high incidence in several domestic animal species and its life-threatening character. Bladder cancer in companion animals shows a complex and still poorly understood biopathology, and this lack of knowledge has limited therapeutic progress over the years. Even so, important advances concerning the identification of tumour markers with clinical applications at the diagnosis, prognosis and therapeutic levels have recently been made, for example, the identification of pathological BRAF mutations. Those advances are now facilitating the introduction of targeted therapies. The present review will address such advances, focusing on small animal oncology and providing the reader with an update on this field. When appropriate, comparisons will be drawn with bladder cancer in human patients, as well as with experimental models of the disease.

Blocking PI3K p110β Attenuates Development of PTEN-Deficient Castration-Resistant Prostate Cancer

A common outcome of androgen deprivation in prostate cancer therapy is disease relapse and progression to castration-resistant prostate cancer (CRPC) via multiple mechanisms. To gain insight into the recent clinical findings that highlighted genomic alterations leading to hyperactivation of PI3K, we examined the roles of the commonly expressed p110 catalytic isoforms of PI3K in a murine model of Pten-null invasive CRPC. While blocking p110α had negligible effects in the development of Pten-null invasive CRPC, either genetic or pharmacological perturbation of p110β dramatically slowed CRPC initiation and progression. Once fully established, CRPC tumors became partially resistant to p110β inhibition, indicating the acquisition of new dependencies. Driven by our genomic analyses highlighting potential roles for the p110β/RAC/PAK1 and β-Catenin pathways in CRPC, we found that combining p110β with RAC/PAK1 or tankyrase inhibitors significantly reduced the growth of murine and human CRPC organoids in vitro and in vivo. Since p110β activity is dispensable for most physiological processes, our studies support novel therapeutic strategies both for preventing disease progression into CRPC and for treating CRPC. Implications: This work establishes p110β as a promising target for preventing the progression of primary PTEN-deficient prostate tumors into CRPC, and for treating established CRPC in combination with RAC/PAK1 or tankyrase inhibitors.

Experimental challenges to modeling prostate cancer heterogeneity

Tumor heterogeneity plays a key role in prostate cancer prognosis, therapy selection, relapse, and acquisition of treatment resistance. Prostate cancer presents a heterogeneous diversity at inter- and intra-tumor and inter-patient levels which are influenced by multiple intrinsic and/or extrinsic factors. Recent studies have started to characterize the complexity of prostate tumors and these different tiers of heterogeneity. In this review, we discuss the most common factors that contribute to tumoral diversity. Moreover, we focus on the description of the in vitro and in vivo approaches, as well as high-throughput technologies, that help to model intra-tumoral diversity. Further understanding tumor heterogeneities and the challenges they present will guide enhanced patient risk stratification, aid the design of more precise therapies, and ultimately help beat this chameleon-like disease.

Exocrine gland structure-function relationships

Fluid secretion by exocrine glandular organs is essential to the survival of mammals. Each glandular unit within the body is uniquely organized to carry out its own specific functions, with failure to establish these specialized structures resulting in impaired organ function. Here, we review glandular organs in terms of shared and divergent architecture. We first describe the structural organization of the diverse glandular secretory units (the end-pieces) and their fluid transporting systems (the ducts) within the mammalian system, focusing on how tissue architecture corresponds to functional output. We then highlight how defects in development of end-piece and ductal architecture impacts secretory function. Finally, we discuss how knowledge of exocrine gland structure-function relationships can be applied to the development of new diagnostics, regenerative approaches and tissue regeneration.

On the Origin of Pancreatic Cancer: Molecular Tumor Subtypes in Perspective of Exocrine Cell Plasticity

Pancreatic ductal adenocarcinoma (PDAC) is a devastating type of cancer. While many studies have shed light into the pathobiology of PDAC, the nature of PDAC's cell of origin remains under debate. Studies in adult pancreatic tissue have unveiled a remarkable exocrine cell plasticity including transitional states, mostly exemplified by acinar to ductal cell metaplasia, but also with recent evidence hinting at duct to basal cell transitions. Single-cell RNA sequencing has further revealed intrapopulation heterogeneity among acinar and duct cells. Transcriptomic and epigenomic relationships between these exocrine cell differentiation states and PDAC molecular subtypes have started to emerge, suggesting different ontogenies for different tumor subtypes. This review sheds light on these diverse aspects with particular focus on studies with human cells. Understanding the "masked ball" of exocrine cells at origin of PDAC and leaving behind the binary acinar vs duct cell classification may significantly advance our insights in PDAC biology.

Collagen deposition correlates with loss of E-cadherin and increased p63 expression in dysplastic conditions of oral submucous fibrosis

This paper focuses on the status of epithelial markers, E-cadherin, and p63 in the backdrop of an abnormal amount of collagen in the sub-mucosa of dysplastic and non-dysplastic grades of OSF. Histologically confirmed OSF and normal oral mucosa samples were procured. Samples were stained by Van Gieson's stain (VG) and immunohistochemistry. The captured images were analyzed by ImageJ software to quantify their grayscale intensities. There was a gradual increase in the intensity of VG stain from normal to non-dysplastic and dysplastic OSF and the differences in their mean grayscale values were found to be significant (p < 0.00001). The intensity of E-cadherin was found to be the highest in non-dysplastic conditions and lowest in dysplastic conditions. The intensity difference of E-cadherin between normal and non-dysplastic OSF was found to be significant (p < 0.00001). The grayscale scale intensity values for p63 in whole epithelium depicted significant differences between normal and diseased conditions but for its intensity, in basal cells, significant differences were found between non-dysplastic and other classes of tissues. There was a positive correlation observed between VG and p63 staining intensity. The diseased oral epithelium demonstrated greater deposition of sub-epithelial collagen fibers along with subsequent loss of E-cadherin and an increased p63 expression.

Metabolism and biomarkers of heterocyclic aromatic amines in humans

Heterocyclic aromatic amines (HAAs) form during the high-temperature cooking of meats, poultry, and fish. Some HAAs also arise during the combustion of tobacco. HAAs are multisite carcinogens in rodents, inducing cancer of the liver, gastrointestinal tract, pancreas, mammary, and prostate glands. HAAs undergo metabolic activation by N-hydroxylation of the exocyclic amine groups to produce the proposed reactive intermediate, the heteroaryl nitrenium ion, which is the critical metabolite implicated in DNA damage and genotoxicity. Humans efficiently convert HAAs to these reactive intermediates, resulting in HAA protein and DNA adduct formation. Some epidemiologic studies have reported an association between frequent consumption of well-done cooked meats and elevated cancer risk of the colorectum, pancreas, and prostate. However, other studies have reported no associations between cooked meat and these cancer sites. A significant limitation in epidemiology studies assessing the role of HAAs and cooked meat in cancer risk is their reliance on food frequency questionnaires (FFQ) to gauge HAA exposure. FFQs are problematic because of limitations in self-reported dietary history accuracy, and estimating HAA intake formed in cooked meats at the parts-per-billion level is challenging. There is a critical need to establish long-lived biomarkers of HAAs for implementation in molecular epidemiology studies designed to assess the role of HAAs in health risk. This review article highlights the mechanisms of HAA formation, mutagenesis and carcinogenesis, the metabolism of several prominent HAAs, and the impact of critical xenobiotic-metabolizing enzymes on biological effects. The analytical approaches that have successfully biomonitored HAAs and their biomarkers for molecular epidemiology studies are presented.

Tissue clearing techniques for three-dimensional optical imaging of intact human prostate and correlations with multi-parametric MRI

BACKGROUND

Tissue clearing technologies have enabled remarkable advancements for in situ characterization of tissues and exploration of the three-dimensional (3D) relationships between cells, however, these studies have predominantly been performed in non-human tissues and correlative assessment with clinical imaging has yet to be explored. We sought to evaluate the feasibility of tissue clearing technologies for 3D imaging of intact human prostate and the mapping of structurally and molecularly preserved pathology data with multi-parametric volumetric MR imaging (mpMRI).

METHODS

Whole-mount prostates were processed with either hydrogel-based CLARITY or solvent-based iDISCO. The samples were stained with a nuclear dye or fluorescently labeled with antibodies against androgen receptor, alpha-methylacyl coenzyme-A racemase, or p63, and then imaged with 3D confocal microscopy. The apparent diffusion coefficient and K^trans maps were computed from preoperative mpMRI.

RESULTS

Quantitative analysis of cleared normal and tumor prostate tissue volumes displayed differences in 3D tissue architecture, marker-specific cell staining, and cell densities that were significantly correlated with mpMRI measurements in this initial, pilot cohort.

CONCLUSIONS

3D imaging of human prostate volumes following tissue clearing is a feasible technique for quantitative radiology-pathology correlation analysis with mpMRI and provides an opportunity to explore functional relationships between cellular structures and cross-sectional clinical imaging.

Histological and immunohistochemical investigation of canine prostate carcinoma with identification of common intraductal carcinoma component

A limited number of species, including men and dogs, spontaneously develop prostate cancer (PC). The histological and molecular relevance of canine PC as a model for the disease in men remains controversial. To address this challenge, this study aimed to assess the histomorphology and expression of basal cell, urothelial and neuroendocrine markers [p63, high molecular weight cytokeratin (HMWCK), Uroplakin 3 (UPIII), neuron‐specific enolase (NSE)] in canine PC (n = 41). Based on histomorphology, 10/41 (24%), 21/41 (51%) and 9/41 (22%) were classified as adenocarcinoma (AC), urothelial carcinoma (UC), and mixed carcinoma, respectively. Tumour inflammation was common, frequently severe [20/41 (49%)], and associated with neutering (p < .02) and urothelial differentiation (p < .02). Most (36/40, 90%) cancers contained only rare cells with basal cell marker expression or were negative. The expression of UPIII was absent or weak in the majority (33/38, 87%) of tumours, with moderate to strong staining in the remaining cases. NSE expression in PC was rare and limited to 2/14 (14%) cases. Tumour extension into benign ducts and glands was a common finding with presence in 17/39 (44%) of carcinomas with and without urothelial differentiation. In conclusion, we confirm that canine PC is characterized by absent or weak expression of basal cell and urothelial markers. Although rare, NSE expression, potentially indicating neuroendocrine differentiation, is reported for the first time in canine PCa. Intraductal carcinoma of the prostate with concurrent invasive PCa (IDCP‐inv) is a frequent, not previously described, finding in dogs with PC.

Linking EMT programmes to normal and neoplastic epithelial stem cells

Epithelial stem cells serve critical physiological functions in the generation, maintenance and repair of diverse tissues through their ability to self-renew and spawn more specialized, differentiated cell types. In an analogous fashion, cancer stem cells have been proposed to fuel the growth, progression and recurrence of many carcinomas. Activation of an epithelial-mesenchymal transition (EMT), a latent cell-biological programme involved in development and wound healing, has been linked to the formation of both normal and neoplastic stem cells, but the mechanistic basis underlying this connection remains unclear. In this Perspective, we outline the instances where aspects of an EMT have been implicated in normal and neoplastic epithelial stem cells and consider the involvement of this programme during tissue regeneration and repair. We also discuss emerging concepts and evidence related to the heterogeneous and plastic cell states generated by EMT programmes and how these bear on our understanding of cancer stem cell biology and cancer metastasis. A more comprehensive accounting of the still-elusive links between EMT programmes and the stem cell state will surely advance our understanding of both normal stem cell biology and cancer pathogenesis.

TP63 Is Significantly Upregulated in Diabetic Kidney

The role of tumor protein 63 (TP63) in regulating insulin receptor substrate 1 (IRS-1) and other downstream signal proteins in diabetes has not been characterized. RNAs extracted from kidneys of diabetic mice (db/db) were sequenced to identify genes that are involved in kidney complications. RNA sequence analysis showed more than 4- to 6-fold increases in TP63 expression in the diabetic mice’s kidneys, compared to wild-type mice at age 10 and 12 months old. In addition, the kidneys from diabetic mice showed significant increases in TP63 mRNA and protein expression compared to WT mice. Mouse proximal tubular cells exposed to high glucose (HG) for 48 h showed significant decreases in IRS-1 expression and increases in TP63, compared to cells grown in normal glucose (NG). When TP63 was downregulated by siRNA, significant increases in IRS-1 and activation of AMP-activated protein kinase (AMPK (p-AMPK-Th¹⁷²)) occurred under NG and HG conditions. Moreover, activation of AMPK by pretreating the cells with AICAR resulted in significant downregulation of TP63 and increased IRS-1 expression. Ad-cDNA-mediated over-expression of tuberin resulted in significantly decreased TP63 levels and upregulation of IRS-1 expression. Furthermore, TP63 knockdown resulted in increased glucose uptake, whereas IRS-1 knockdown resulted in a decrease in the glucose uptake. Altogether, animal and cell culture data showed a potential role of TP63 as a new candidate gene involved in regulating IRS-1 that may be used as a new therapeutic target to prevent kidney complications in diabetes.

ERG orchestrates chromatin interactions to drive prostate cell fate reprogramming

Although cancer is commonly perceived as a disease of dedifferentiation, the hallmark of early-stage prostate cancer is paradoxically the loss of more plastic basal cells and the abnormal proliferation of more differentiated secretory luminal cells. However, the mechanism of prostate cancer proluminal differentiation is largely unknown. Through integrating analysis of the transcription factors (TFs) from 806 human prostate cancers, we found that ERG was highly correlated with prostate cancer luminal subtyping. ERG overexpression in luminal epithelial cells inhibited those cells' normal plasticity to transdifferentiate into a basal lineage, and ERG superseded PTEN loss, which favored basal differentiation. ERG KO disrupted prostate cell luminal differentiation, whereas AR KO had no such effects. Trp63 is a known master regulator of the prostate basal lineage. Through analysis of 3D chromatin architecture, we found that ERG bound and inhibited the enhancer activity and chromatin looping of a Trp63 distal enhancer, thereby silencing its gene expression. Specific deletion of the distal ERG binding site resulted in the loss of ERG-mediated inhibition of basal differentiation. Thus, ERG, in its fundamental role in lineage differentiation in prostate cancer initiation, orchestrated chromatin interactions and regulated prostate cell lineage toward a proluminal program.

Progenitors in prostate development and disease

The prostate develops by epithelial budding and branching processes that occur during fetal and postnatal stages. The adult prostate demonstrates remarkable regenerative capacity, with the ability to regrow to its original size over multiple cycles of castration and androgen administration. This capacity for controlled regeneration prompted the search for an androgen-independent epithelial progenitor in benign prostatic hyperplasia (BPH) and prostate cancer (PCa). BPH is hypothesized to be a reawakening of ductal branching, resulting in the formation of new proximal glands, all while androgen levels are decreasing in the aging male. Advanced prostate cancer can be slowed with androgen deprivation, but resistance eventually occurs, suggesting the existence of an androgen-independent progenitor. Recent studies indicate that there are multiple castration-insensitive epithelial cell types in the proximal area of the prostate, but not all act as progenitors during prostate development or regeneration. This review highlights how recent cellular and anatomical studies are changing our perspective on the identity of the prostate progenitor.

Immune Escape in Prostate Cancer: Known and Predicted Mechanisms and Targets

Complex immune evasion mechanisms and lack of biomarkers predicting responsiveness to immune checkpoint blockade therapies compromise immunotherapy's therapeutic efficacy for patients with prostate cancer. The authors review established and nominated immune evasion mechanisms in prostate cancer and discuss how the precise treatment strategies can be developed to improve efficacy of immunotherapy.

Olfactomedin 4 mediation of prostate stem/progenitor-like cell proliferation and differentiation via MYC

Olfactomedin 4 (OLFM4) is expressed in normal prostate epithelial cells and immortalized normal human prostate epithelial cells (RWPE1), but the identity of OLFM4-expressing cells within these populations and OLFM4's physiological functions in these cells have not been elucidated. Using single-cell RNA sequencing analysis, we found here that OLFM4 was expressed in multiple stem/progenitor-like cell populations in both the normal prostate epithelium and RWPE1 cells and was frequently co-expressed with KRT13 and LY6D in RWPE1 cells. Functionally, OLFM4-knockout RWPE1 cells exhibited enhanced proliferation of the stem/progenitor-like cell population, shifts stem/progenitor-like cell division to favor symmetric division and differentiated into higher levels PSA expression cells in organoid assays compared with OLFM4-wild RWPE1 cells. Bulk-cell RNA sequencing analysis pinpointed that cMYC expression were enhanced in the OLFM4-knockout RWPE1 cells compared with OLFM4-wild cells. Molecular and signaling pathway studies revealed an increase in the WNT/APC/MYC signaling pathway gene signature, as well as that of MYC target genes that regulate multiple biological processes, in OLFM4-knockout RWPE1 cells. These findings indicated that OLFM4 is co-expressed with multiple stem/progenitor cell marker genes in prostate epithelial cells and acts as a novel mediator in prostate stem/progenitor cell proliferation and differentiation.

Oncogenic transformation of human benign prostate hyperplasia with chronic cadmium exposure

Experimentally, it has been proved that cadmium served as an effective carcinogen and able to induce tumors in rodents in a dose-specific manner. However, systemic evaluation of cadmium exposure for the transformation of prostatic hyperplasia into prostate cancer (PCa) is still unclear. In the present study, an attempt has been made to establish cadmium-induced human prostate carcinogenesis using an in vitro model of BPH cells. Wide range of cadmium concentrations, i.e., 1 nM, 10 nM, 100 nM and 1μM, were chronically exposed to the human BPH cells for transformation into PCa and monitored using cell and molecular biology approaches. After eight weeks of exposure, the cells showed subtle morphological changes and shifts of cell cycle in the G2M phase. Significant increase in expression of prostatic genes AR, PSA, ER-β, and 5αR with increased nuclear localization of AR and pluripotency markers Cmyc, Klf4 indicated the carcinogenic effect of Cd. Further, the BPH cells exposed to Cd showed a substantial increase in the secretion of MMP-2 and MMP-9, influencing migratory potential of the cells along with decreased expression of the p63 protein which further strengthen the progression towards carcinogenesis and aggressive tumor studies. Data from the present study state that Cd exhibited marked invasiveness in BPH cells. These observations established a connecting link of BPH towards PCa pathogenesis. Further, the study will also help in investigating the intricate pathways involved in cancer progression.

Tp63-expressing adult epithelial stem cells cross lineages boundaries revealing latent hairy skin competence

The formation of hair follicles, a landmark of mammals, requires complex mesenchymal–epithelial interactions and it is commonly believed that embryonic epidermal cells are the only cells that can respond to hair follicle morphogenetic signals in vivo. Here, we demonstrate that epithelial stem cells of non-skin origin (e.g. that of cornea, oesophagus, vagina, bladder, prostate) that express the transcription factor Tp63, a master gene for the development of epidermis and its appendages, can respond to skin morphogenetic signals. When exposed to a newborn skin microenvironment, these cells express hair-follicle lineage markers and contribute to hair follicles, sebaceous glands and/or epidermis renewal. Our results demonstrate that lineage restriction is not immutable and support the notion that all Tp63-expressing epithelial stem cells, independently of their embryonic origin, have latent skin competence explaining why aberrant hair follicles or sebaceous glands are sometimes observed in non-skin tissues (e.g. in cornea, vagina or thymus).

Adult stem cells are thought to be fate restricted to lineages distinct to their tissue of origin. Here, the authors demonstrate that Tp63 expressing epithelial stem cells from several disparate tissues can respond to skin morphogenetic signals and contribute to hair follicles, sebaceous glands and/or epidermis.

TP63 links chromatin remodeling and enhancer reprogramming to epidermal differentiation and squamous cell carcinoma development

Squamous cell carcinoma (SCC) is an aggressive malignancy that can originate from various organs. TP63 is a master regulator that plays an essential role in epidermal differentiation. It is also a lineage-dependent oncogene in SCC. ΔNp63α is the prominent isoform of TP63 expressed in epidermal cells and SCC, and overexpression promotes SCC development through a variety of mechanisms. Recently, ΔNp63α was highlighted to act as an epidermal-specific pioneer factor that binds closed chromatin and enhances chromatin accessibility at epidermal enhancers. ΔNp63α coordinates chromatin-remodeling enzymes to orchestrate the tissue-specific enhancer landscape and three-dimensional high-order architecture of chromatin. Moreover, ΔNp63α establishes squamous-like enhancer landscapes to drive oncogenic target expression during SCC development. Importantly, ΔNp63α acts as an upstream regulator of super enhancers to activate a number of oncogenic transcripts linked to poor prognosis in SCC. Mechanistically, ΔNp63α activates genes transcription through physically interacting with a number of epigenetic modulators to establish enhancers and enhance chromatin accessibility. In contrast, ΔNp63α also represses gene transcription via interacting with repressive epigenetic regulators. ΔNp63α expression is regulated at multiple levels, including transcriptional, post-transcriptional, and post-translational levels. In this review, we summarize recent advances of p63 in epigenomic and transcriptional control, as well as the mechanistic regulation of p63.

Improving prostate cancer classification in H&E tissue micro arrays using Ki67 and P63 histopathology

Histopathology of Hematoxylin and Eosin (H&E)-stained tissue obtained from biopsy is commonly used in prostate cancer (PCa) diagnosis. Automatic PCa classification of digitized H&E slides has been developed before, but no attempts have been made to classify PCa using additional tissue stains registered to H&E. In this paper, we demonstrate that using H&E, Ki67 and p63-stained (3-stain) tissue improves PCa classification relative to H&E alone. We also show that we can infer PCa-relevant Ki67 and p63 information from the H&E slides alone, and use it to achieve H&E-based PCa classification that is comparable to the 3-stain classification. Reported improvements apply to classifying benign vs. malignant tissue, and low grade (Gleason group 2) vs. high grade (Gleason groups 3,4,5) cancer. Specifically, we conducted four classification tasks using 333 tissue samples extracted from 231 radical prostatectomy patients: regression tree-based classification using either (i) 3-stain features, with a benign vs malignant area under the curve (AUC = 92.9%), or (ii) real H&E features and H&E features learned from Ki67 and p63 stains (AUC = 92.4%), as well as deep learning classification using either (iii) real 3-stain tissue patches (AUC = 94.3%) and (iv) real H&E patches and generated Ki67 and p63 patches (AUC = 93.0%) using a deep convolutional generative adversarial network. Classification performance was assessed with Monte Carlo cross validation and quantified in terms of the Area Under the Curve, Brier score, sensitivity, and specificity. Our results are interpretable and indicate that the standard H&E classification could be improved by mimicking other stain types.

TAp63 and ΔNp63 (p40) in prostate adenocarcinomas: ΔNp63 associates with a basal-like cancer stem cell population but not with metastasis

Like other malignancies, prostate tumors are thought to contain cancer stem-like cells (CSCs) that are responsible for growth, metastasis, and therapy resistance. ΔNp63 (also called p40) is a regulator of normal prostate stem/progenitor cell activities and a marker of normal basal epithelial cells. The levels of ΔNp63 are reduced in prostate adenocarcinomas, although there is also evidence that ΔNp63 is involved in CSC regulation and drives metastasis to the bone. We studied metastatic deposits of prostate cancers with isoform-specific ΔNp63 and TAp63 antibodies. We identified p63-positive cells in only 3 of 42 metastatic prostate tumors (7%), including 2/38 (5.3%) "usual-type" adenocarcinomas. ΔNp63 and TAp63 isoforms were present in the nuclei of a small subpopulation (< 1%) of tumor cells in these metastases. ΔNp63-positive cells showed a basal-like cell phenotype (cytokeratin 8- and androgen receptor-negative, high molecular weight cytokeratin- and cytokeratin 19-positive), distinct from the tumor bulk. TAp63-positive cells were similar but were sometimes cytokeratin 8-positive. A subset of ΔNp63-positive tumor cells were CD44-positive, a marker of "basal" CSCs but were not positive for the "epithelial" CSC marker ALDH1. TAp63 was not associated with either of these CSC markers. None of the tumors containing p63-positive cells showed evidence of bone metastasis, compared with 28% of the p63-negative tumors. These data show that both ΔNp63 and TAp63 are present in only a small proportion of prostate adenocarcinomas and do not associate with metastasis. The data suggest heterogeneity of CSCs in prostate cancer, similar to other cancer types.

CXCL12γ induces human prostate and mammary gland development

BACKGROUND

Epithelial stem cells (ESCs) demonstrate a capacity to maintain normal tissues homeostasis and ESCs with a deregulated behavior can contribute to cancer development. The ability to reprogram normal tissue epithelial cells into prostate or mammary stem-like cells holds great promise to help understand cell of origin and lineage plasticity in prostate and breast cancers in addition to understanding normal gland development. We previously showed that an intracellular chemokine, CXCL12γ induced cancer stem cells and neuroendocrine characteristics in both prostate and breast adenocarcinoma cell lines. However, its role in normal prostate or mammary epithelial cell fate and development remains unknown. Therefore, we sought to elucidate the functional role of CXCL12γ in the regulation of ESCs and tissue development.

METHODS

Prostate epithelial cells (PNT2) or mammary epithelial cells (MCF10A) with overexpressed CXCL12γ was characterized by quantitative real-time polymerase chain reaction, Western blots, and immunofluorescence for lineage marker expression, and fluorescence activated cell sorting analyses and sphere formation assays to examine stem cell surface phenotype and function. Xenotransplantation animal models were used to evaluate gland or acini formation in vivo.

RESULTS

Overexpression of CXCL12γ promotes the reprogramming of cells with a differentiated luminal phenotype to a nonluminal phenotype in both prostate (PNT2) and mammary (MCF10A) epithelial cells. The CXCL12γ-mediated nonluminal type cells results in an increase of epithelial stem-like phenotype including the subpopulation of EPCAM^Lo /CD49f^Hi /CD24^Lo /CD44^Hi cells capable of sphere formation. Critically, overexpression of CXCL12γ promotes the generation of robust gland-like structures from both prostate and mammary epithelial cells in in vivo xenograft animal models.

CONCLUSIONS

CXCL12γ supports the reprogramming of epithelial cells into nonluminal cell-derived stem cells, which facilitates gland development.

B lymphoma Moloney murine leukemia virus insertion region 1: An oncogenic mediator in prostate cancer

B lymphoma Moloney murine leukemia virus insertion region 1 (BMI1), a core member of polycomb repressive complex 1 (PRC1), has been intensely investigated in the field of cancer epigenetics for decades. Widely known as a critical regulator in cellular physiology, BMI1 is essential in self-renewal and differentiation in different lineages of stem cells. BMI1 also plays a significant role in cancer etiology for its involvement in pathological progress such as epithelial–mesenchymal transition (EMT) and cancer stem cell maintenance, propagation, and differentiation. Importantly, overexpression of BMI1 is predictive for drug resistance, tumor recurrence, and eventual therapy failure of various cancer subtypes, which renders the pharmacological targeting at BMI1 as a novel and promising therapeutic approach. The study on prostate cancer, a prevalent hormone-related cancer among men, has promoted enormous research advancements in cancer genetics and epigenetics. This review summarizes the role of BMI1 as an oncogenic and epigenetic regulator in tumor initiation, progression, and relapse of prostate cancer.

Slug-expressing mouse prostate epithelial cells have increased stem cell potential

Deciphering the properties of adult stem cells is crucial for understanding of their role in healthy tissue and in cancer progression as well. Both stem cells and cancer stem cells have shown association with epithelial-to-mesenchymal transition (EMT) in various tissue types. Aiming to investigate the epithelial and mesenchymal phenotypic traits in adult mouse prostate, we sorted subpopulations of basal prostate stem cells (mPSCs) and assessed the expression levels of EMT regulators and markers with custom-designed gene expression array. The population of mPSCs defined by a Lin^-/Sca-1⁺CD49f^hi/Trop-2⁺ (LSC Trop-2⁺) surface phenotype was enriched in mesenchymal markers, especially EMT master regulator Slug, encoded by the Snai2 gene. To further dissect the role of Slug in mPSCs, we used transgenic Snai2^tm1.1Wbg reporter mouse strain. Using this model, we confirmed the presence of mesenchymal traits and increase of organoid forming capacity in Slug⁺ population of mPSCs. The Slug⁺-derived organoids comprised all prostate epithelial cell types - basal, luminal, and neuroendocrine. Collectively, these data uncover the important role of Slug expression in the physiology of mouse prostate stem cells.

Cellular organization and histogenesis of adenosquamous carcinoma of the pancreas: evidence supporting the squamous metaplasia concept

Adenosquamous carcinoma of the pancreas (ASCAP) is characterized by conventional pancreatic ductal adenocarcinoma (PDAC) and squamous carcinoma components with at least 30% of the tumour showing squamous differentiation. To get further insight into the histogenesis of these lesions, we analysed the cellular organization of ASCAP compared to PDACs. Using Immunohistochemistry and triple immunofluorescence labelling studies for keratins, p63, p40, MUC1, MUC2, MUC5AC, Ki67, and EGFR we demonstrate that many ASCAPs contain a transitional zone between the K8/18-positive adenocarcinomatous component and the p63+ /p40+ /K5/K14+ squamous component initiated by the expression of p63 in K8/18+ adenocarcinomatous cells and the appearance of basally located p63+ K5/14+ cells. p63+ K5/14+ cells give rise to fully developed squamous differentiation. Notably, 25% of conventional PDACs without histologically recognizable squamous component contain foci of p63+ p40+ and K5/14+ cells similar to the transitional zone. Our data provide evidence that the squamous carcinoma components of ASCAPs originate from pre-existing PDAC via transdifferentiation of keratin K8/18-positive glandular cells to p63-, p40-, and keratin K5/14-positive squamous carcinoma cells supporting the squamous metaplasia hypothesis. Thus our findings provide new evidence about the cellular process behind squamous differentiation in ASCAPs.

Human stroma and epithelium co-culture in a microfluidic model of a human prostate gland

The prostate is a walnut-sized gland that surrounds the urethra of males at the base of the bladder comprising a muscular portion, which controls the release of urine, and a glandular portion, which secretes fluids that nourish and protect sperms. Here, we report the development of a microfluidic-based model of a human prostate gland. The polydimethylsiloxane (PDMS) microfluidic device, consisting of two stacked microchannels separated by a polyester porous membrane, enables long-term in vitro cocultivation of human epithelial and stromal cells. The porous separation membrane provides an anchoring scaffold for long-term culturing of the two cell types on its opposite surfaces allowing paracrine signaling but not cell crossing between the two channels. The microfluidic device is transparent enabling high resolution bright-field and fluorescence imaging. Within this coculture model of a human epithelium/stroma interface, we simulated the functional development of the in vivo human prostate gland. We observed the successful differentiation of basal epithelial cells into luminal secretory cells determined biochemically by immunostaining with known differentiation biomarkers, particularly androgen receptor expression. We also observed morphological changes where glandlike mounds appeared with relatively empty centers reminiscent of prostatic glandular acini structures. This prostate-on-a-chip will facilitate the direct evaluation of paracrine and endocrine cross talk between these two cell types as well as studies associated with normal vs disease-related events such as prostate cancer.

ΔNp63 transcript loss in bladder cancer constitutes an independent molecular predictor of TaT1 patients post-treatment relapse and progression

PURPOSE

Bladder cancer represents a major cause of malignancy-related morbidity and the most expensive per-patient-to-treat cancer, due to the lifelong surveillance of the patients. Accurate disease prognosis is essential in establishing personalized treatment decisions; yet optimum tools for precise risk stratification remain a competing task. In the present study, we have performed the complete evaluation of TP63 clinical significance in improving disease prognosis.

METHODS

The levels of ΔNp63 and TAp63 transcripts of TP63 were quantified in 342 bladder tissue specimens of our screening cohort (n = 182). Hedegaard et al. (Cancer Cell 30:27-42. doi:10.1016/j.ccell.2016.05.004, 2016) (n = 476) and TCGA provisional (n = 413) were used as validation cohorts for NMIBC and MIBC, respectively. Survival analysis was performed using recurrence and progression for NMIBC or mortality for MIBC as endpoint events. Bootstrap analysis was performed for internal validation, while decision curve analysis was used for the evaluation of the clinical net benefit on disease prognosis.

RESULTS

ΔNp63 was significantly expressed in bladder tissues, and was found to be over-expressed in bladder tumors. Interestingly, reduced ΔNp63 levels were correlated with muscle-invasive disease, high-grade tumors and high-EORTC-risk NMIBC patients. Moreover, ΔNp63 loss was independently associated with higher risk for NMIBC relapse (HR = 2.730; p = 0.007) and progression (HR = 7.757; p = 0.016). Hedegaard et al. and TCGA validation cohorts confirmed our findings. Finally, multivariate models combining ΔΝp63 loss with established prognostic markers led to a superior clinical benefit for NMIBC prognosis and risk stratification.

CONCLUSIONS

ΔΝp63 loss is associated with adverse outcome of NMIBC resulting in superior prediction of NMIBC early relapse and progression.

Prostate Stem Cells and Cancer Stem Cells

Stem/progenitor cells play central roles in processes of organogenesis and tissue maintenance, whereas cancer stem cells (CSCs) are thought to drive tumor malignancy. Here, we review recent progress in the identification and analysis of normal prostate stem/progenitor cells as well as putative CSCs in both genetically engineered mouse models as well as in human tissue. We also discuss studies that have investigated the cell type of origin for prostate cancer. In addition, we provide a critical assessment of methodologies used in stem cell analyses and outline directions for future research.

Signature maps for automatic identification of prostate cancer from colorimetric analysis of H&E- and IHC-stained histopathological specimens

Prostate cancer (PCa) is a major cause of cancer death among men. The histopathological examination of post-surgical prostate specimens and manual annotation of PCa not only allow for detailed assessment of disease characteristics and extent, but also supply the ground truth for developing of computer-aided diagnosis (CAD) systems for PCa detection before definitive treatment. As manual cancer annotation is tedious and subjective, there have been a number of publications describing methods for automating the procedure via the analysis of digitized whole-slide images (WSIs). However, these studies have focused only on the analysis of WSIs stained with hematoxylin and eosin (H&E), even though there is additional information that could be obtained from immunohistochemical (IHC) staining. In this work, we propose a framework for automating the annotation of PCa that is based on automated colorimetric analysis of both H&E and IHC WSIs stained with a triple-antibody cocktail against high-molecular weight cytokeratin (HMWCK), p63, and α-methylacyl CoA racemase (AMACR). The analysis outputs were then used to train a regression model to estimate the distribution of cancerous epithelium within slides. The approach yielded an AUC of 0.951, sensitivity of 87.1%, and specificity of 90.7% as compared to slide-level annotations, and generalized well to cancers of all grades.

A pivotal role of androgen signaling in Notch-responsive cells in prostate development, maturation, and regeneration

Androgen signaling is essential for prostate development, morphogenesis, and regeneration. Emerging evidence also indicates a regulatory role of Notch signaling in prostate development, differentiation, and growth. However, the collaborative regulatory mechanisms of androgen and Notch signaling during prostate development, growth, and regeneration are largely unknown. Hairy and Enhancer of Split 1 (Hes1) is a transcriptional regulator of Notch signaling pathways, and its expression is responsive to Notch signaling. Hes1-expressing cells have been shown to possess the regenerative capability to repopulate a variety of adult tissues. In this study, we developed new mouse models to directly assess the role of the androgen receptor in prostatic Hes1-expressing cells. Selective deletion of AR expression in embryonic Hes1-expressing cells impeded early prostate development both in vivo and in tissue xenograft experiments. Prepubescent deletion of AR expression in Hes1-expressing cells resulted in prostate glands containing abnormalities in cell morphology and gland architecture. A population of castration-resistant Hes1-expressing cells was revealed in the adult prostate, with the ability to repopulate prostate epithelium following androgen supplementation. Deletion of AR in Hes1-expressing cells diminishes their regenerative ability. These lines of evidence demonstrate a critical role for the AR in Notch-responsive cells during the course of prostate development, morphogenesis, and regeneration, and implicate a mechanism underlying interaction between the androgen and Notch signaling pathways in the mouse prostate.

Sox2 Expression Marks Castration-Resistant Progenitor Cells in the Adult Murine Prostate

Identification of defined epithelial cell populations with progenitor properties is critical for understanding prostatic development and disease. Here, we demonstrate that Sox2 expression is enriched in the epithelial cells of the proximal prostate adjacent to the urethra. We use lineage tracing of Sox2-positive cells during prostatic development, homeostasis, and regeneration to show that the Sox2 lineage is capable of self-renewal and contributes to prostatic regeneration. Persisting luminal cells express Sox2 after castration, highlighting a potential role for Sox2 in cell survival and castration-resistance. In addition to revealing a novel progenitor population in the prostate, these data implicate Sox2 as a regulatory factor of adult prostate epithelial stem cells. Stem Cells 2019;37:690-700.

Spatial analysis of p63, K5 and K7 defines two groups of progenitor cells that differentially contribute to the maintenance of normal sebaceous glands, extraocular sebaceous carcinoma and benign sebaceous tumors

The histogenesis of extraocular sebaceous carcinomas is - in contrast to ocular sebaceous carcinomas - unclear, and information about the exact cellular architecture of these lesions and even of the normal sebaceous gland is still scarce. This study attempts to elucidate the histogenesis of sebaceous tumors, using multicolor immunofluorescence stainings to analyze 21 cases of sebaceous tumors (six each of extraocular sebaceous carcinoma, sebaceous adenoma and sebaceoma, and three cases of steatocystomas) and eight cases of normal sebaceous glands for p63, several keratins, androgen receptor, adipophilin, epithelial membrane antigen (EMA) and Ki-67. The data of this observational study provide evidence for the existence of two subpopulations of progenitors in normal sebaceous glands: (i) p63⁺ K5⁺ progenitors which generate the K10⁺ luminal cells of sebaceous ducts; and (ii) p63⁺ K5⁺ K7⁺ progenitors which finally generate K7⁺ adipophilin⁺ EMA⁺ sebocytes. Without exception, all types of sebaceous tumors contained p63⁺ K5⁺ cells. Furthermore, these tumors showed a cellular hierarchy and differentiation to adipophilin⁺ and/or EMA⁺ mature sebocytes and to K10⁺ ductal cells through intermediary cells. Notably, a considerable number of sebaceous tumors lack the K7 pathway of cell maintenance in the normal sebaceous lobule. Based on our data, we propose a cellular algorithmic model of the hierarchy of normal sebaceous glands and of sebocytic tumors in which p63⁺ K5⁺ cells play a major role.

LEADeR role of miR-205 host gene as long noncoding RNA in prostate basal cell differentiation

Though miR-205 function has been largely characterized, the nature of its host gene, MIR205HG, is still completely unknown. Here, we show that only lowly expressed alternatively spliced MIR205HG transcripts act as de facto pri-miRNAs, through a process that involves Drosha to prevent unfavorable splicing and directly mediate miR-205 excision. Notably, MIR205HG-specific processed transcripts revealed to be functional per se as nuclear long noncoding RNA capable of regulating differentiation of human prostate basal cells through control of the interferon pathway. At molecular level, MIR205HG directly binds the promoters of its target genes, which have an Alu element in proximity of the Interferon-Regulatory Factor (IRF) binding site, and represses their transcription likely buffering IRF1 activity, with the ultimate effect of preventing luminal differentiation. As MIR205HG functions autonomously from (albeit complementing) miR-205 in preserving the basal identity of prostate epithelial cells, it warrants reannotation as LEADeR (Long Epithelial Alu-interacting Differentiation-related RNA).

miR-205 is known to have context-dependent tumor suppressive or oncogenic roles. Here, the authors report the host gene of miR-205, MIR205HG as a nuclear lincRNA that maintains the basal identity of prostate cell and prevents luminal cell differentiation via the repression of interferon responsive genes.

Cells of Origin for Prostate Cancer

Comprehensive knowledge of the normal prostate epithelial lineage hierarchy is a prerequisite to investigate the identity of the cells of origin for prostate cancer. The basal and luminal cells constitute most of the prostate epithelium and have been the major focuses of the study on the cells of origin for prostate cancer. Much progress has been made during the past few decades, mainly using mouse models, to understand the inter-lineage relationship and intra-lineage heterogeneity in adults as well as the lineage plasticity during conditions of stress. These studies have concluded that the adult mouse prostate basal and luminal cells are largely independently sustained under physiological conditions, but both types of cells possess the capacity for bipotent differentiation under stress or artificial experimental conditions. However, the existence or the identity of the putative progenitors within each lineage warrants further investigation. Whether the human prostate lineage hierarchy is completely the same as that of the mouse remains uncertain. Experiments from independent groups have demonstrated that both types of cells in mice and humans can serve as targets for transformation. But controversies remain whether the disease from distinct cells of origin display different clinical behaviors. Further investigation of the intra-lineage heterogeneity will provide new insights into this issue. Understanding the identity of the cells of origin for prostate cancer will help identify novel prognostic markers for early detection of aggressive prostate cancers, provide insights into the therapeutic vulnerability of these tumors, and inspire novel therapeutic strategies.

Dietary Carcinogens and DNA Adducts in Prostate Cancer

Prostate cancer (PC) is the most commonly diagnosed non-cutaneous cancer and the second leading cause of cancer-related to death in men. The major risk factors for PC are age, family history, and African American ethnicity. Epidemiological studies have reported large geographical variations in PC incidence and mortality, and thus lifestyle and dietary factors influence PC risk. High fat diet, dairy products, alcohol and red meats, are considered as risk factors for PC. This book chapter provides a comprehensive, literature-based review on dietary factors and their molecular mechanisms of prostate carcinogenesis. A large portion of our knowledge is based on epidemiological studies where dietary factors such as cancer promoting agents, including high-fat, dairy products, alcohol, and cancer-initiating genotoxicants formed in cooked meats have been evaluated for PC risk. However, the precise mechanisms in the etiology of PC development remain uncertain. Additional animal and human cell-based studies are required to further our understandings of risk factors involved in PC etiology. Specific biomarkers of chemical exposures and DNA damage in the prostate can provide evidence of cancer-causing agents in the prostate. Collectively, these studies can improve public health research, nutritional education and chemoprevention strategies.