Club-like cells in proliferative inflammatory atrophy of the prostate

Spatial profiling of ANO7 in prostate tissue: links to AR-signalling-associated lipid metabolism and inflammation

Prostate cancer (PrCa) is highly prevalent in the Western world. Currently, however, there are many unmet needs in PrCa care, for example in distinguishing between clinically significant and indolent cases in early phases of the disease. ANO7 is a prostate-specific gene associated with PrCa risk and prognosis, but its exact function in the prostate remains unclear. This study investigates the role of ANO7 in benign prostatic epithelium using spatial transcriptomics by examining differences between ANO7-expressing and non-expressing epithelial regions and their corresponding stromal compartments. A total of 18,676 protein-coding genes were assessed from prostatectomy samples collected from patients with localised prostate cancer. In the collected sample cohort, ANO7 exhibited a distinct, heterogeneous, on-off epithelial expression pattern, enabling an in-depth analysis of ANO7-dependent processes. ANO7-positive epithelium was predominantly enriched with luminal epithelial cells and a specific NK cell subtype, CD56bright. In contrast, ANO7-negative regions were characterised by enrichment of club cells, inflammation, and features of proliferative inflammatory atrophy. Gene-set enrichment analysis revealed that ANO7 expression is associated with androgen receptor (AR) signalling and lipid metabolism. A detailed analysis of differentially expressed genes identified an ANO7- signature, which consisted of genes co-expressed with ANO7 in luminal cells, that demonstrated high consistency in bulk RNA-sequencing (RNA-seq) data. The ANO7-signature was enriched for AR-regulated genes, which highlighted lipid metabolism processes, particularly arachidonic acid metabolism, as a key metabolic feature of the ANO7-positive epithelium. Furthermore, the ANO7-signature demonstrated clinical significance in low-grade PrCa, correlating with a better response to therapy. In summary, these results highlight the potential role of ANO7 in regulating lipid metabolism associated with androgen signalling in benign luminal cells and low-grade cancer, reinforcing the hypothesis that ANO7 functions as a tumour suppressor. © 2025 The Pathological Society of Great Britain and Ireland.

Diet and the microbiome as mediators of prostate cancer risk, progression, and therapy response

Complex relationships between the human microbiome and cancer are increasingly recognized for cancer sites that harbor commensal microbial communities such as the gut, genitourinary tract, and skin. For organ sites that likely do not contain commensal microbiota, there is still a substantial capacity for the human-associated microbiota to influence disease etiology across the cancer spectrum. We propose such a relationship for prostate cancer, the most commonly diagnosed cancer in males in the United States. This review explores the current evidence for a role for the urinary and gut microbiota in prostate cancer risk, via both direct interactions (prostate infections) and long-distance interactions such as via the metabolism of procarcinogenic or anticarcinogenic dietary metabolites. We further explore a newly recognized role of the gut microbiota in mediating cancer treatment response or resistance either via production of androgens and/or procarcinogenic metabolites or via direct metabolism of anticancer drugs that are used to treat advanced disease. Overall, we present the current state of knowledge relating to how the human microbiome mediates prostate cancer risk, progression, and therapy response, as well as suggest future research directions for the field.

Uncovering somatic genetic drivers in prostate cancer through comprehensive genome-wide analysis

Given that hereditary prostate cancer (PCa) accounts for only a small fraction of PCa phenotypes, there is still a substantial journey ahead in exploring the somatic genetic drivers contributing to sporadic PCa. The expression quantitative trait loci (eQTLs) data were sourced from the GTEx dataset for prostate-specific genes, and the summary statistic information was collected for 5854 genes. Genetic associations with PCa were extracted from three well-established consortiums: the UK Biobank (9131 cases and 173,493 controls), the PRACTICAL study (79,148 cases and 61,106 controls), and the FinnGen cohort (13,216 cases and 119,948 controls). To prioritize potential causal targets, additional analysis, including the protein-protein interaction (PPI), The Cancer Genome Atlas (TCGA) dataset, and the single-cell-type expression analysis, was performed. Generally, a total of 150 common significant genes with the same causal association with PCa were identified. Out of the 150 genes examined, 67.33% (101/150) were found to have protein-coding functions, while only 30.67% (46/150) of these genes had prior mentions in the scientific literature. Notably, the analysis of the TCGA dataset showed that only 44.67% (67/150) of the genes produced consistent results with the Mendelian randomization (MR) analysis. Furthermore, the evaluation of single-cell RNA-seq data and colocalization analysis singled out MSMB as a critical gene associated with the occurrence of PCa. We pinpointed a range of prostate-specific genes that display causal associations with the onset of PCa. Among these, the MSMB gene emerged as a pivotal factor linked to PCa, demonstrating robust consistency across all four assessments, including the MR, TCGA dataset, single-cell RNA-seq data, and colocalization analysis. These findings provided fresh perspectives on the pathogenesis of PCa and presented potential targets for drug development.

Overexpression of fibroblast activation protein (FAP) in the stroma of proliferative inflammatory atrophy (PIA) and primary adenocarcinoma of the prostate

Fibroblast activation protein (FAP) is a serine protease upregulated at sites of tissue remodelling and cancer that represents a promising therapeutic and molecular imaging target. In prostate cancer, studies of FAP expression using tissue microarrays are conflicting, such that its clinical potential is unclear. Furthermore, little is known regarding FAP expression in benign prostatic tissues. Here we demonstrated, using a novel iterative multiplex immunohistochemistry assay in standard tissue sections, that FAP was nearly absent in normal regions ​but was increased consistently in regions of proliferative inflammatory atrophy (PIA). In carcinoma, FAP was expressed in all cases ​but was highly heterogeneous. High FAP levels were associated with increased pathological stage and cribriform morphology. We verified that FAP levels in cancer correlated with CD163+ M2 macrophage density. In this first report to quantify FAP protein in benign prostate and primary tumours, using standard large tissue sections, we clarify that FAP is present in all primary prostatic carcinomas, supporting its potential clinical relevance. The finding of high levels of FAP within PIA supports the injury/regeneration model for its pathogenesis and suggests that it harbours a protumourigenic stroma, yet ​high levels of FAP in benign regions could lead to false-positive FAP-based molecular imaging results in clinically localised prostate cancer.

Single cell and spatial transcriptomics highlight the interaction of club-like cells with immunosuppressive myeloid cells in prostate cancer

Prostate cancer treatment resistance is a significant challenge facing the field. Genomic and transcriptomic profiling have partially elucidated the mechanisms through which cancer cells escape treatment, but their relation toward the tumor microenvironment (TME) remains elusive. Here we present a comprehensive transcriptomic landscape of the prostate TME at multiple points in the standard treatment timeline employing single-cell RNA-sequencing and spatial transcriptomics data from 120 patients. We identify club-like cells as a key epithelial cell subtype that acts as an interface between the prostate and the immune system. Tissue areas enriched with club-like cells have depleted androgen signaling and upregulated expression of luminal progenitor cell markers. Club-like cells display a senescence-associated secretory phenotype and their presence is linked to increased polymorphonuclear myeloid-derived suppressor cell (PMN-MDSC) activity. Our results indicate that club-like cells are associated with myeloid inflammation previously linked to androgen deprivation therapy resistance, providing a rationale for their therapeutic targeting.

Convergent alterations in the tumor microenvironment of MYC-driven human and murine prostate cancer

How prostate cancer cells and their precursors mediate changes in the tumor microenvironment (TME) to drive prostate cancer progression is unclear, in part due to the inability to longitudinally study the disease evolution in human tissues. To overcome this limitation, we perform extensive single-cell RNA-sequencing (scRNA-seq) and molecular pathology of the comparative biology between human prostate cancer and key stages in the disease evolution of a genetically engineered mouse model (GEMM) of prostate cancer. Our studies of human tissues reveal that cancer cell-intrinsic activation of MYC signaling is a common denominator across the well-known molecular and pathological heterogeneity of human prostate cancer. Cell communication network and pathway analyses in GEMMs show that MYC oncogene-expressing neoplastic cells, directly and indirectly, reprogram the TME during carcinogenesis, leading to a convergence of cell state alterations in neighboring epithelial, immune, and fibroblast cell types that parallel key findings in human prostate cancer.

Innovative Drug Modalities for the Treatment of Advanced Prostate Cancer

Prostate cancer, a prevalent malignancy affecting the prostate gland, is a significant global health concern. Androgen-deprivation therapy (ADT) has proven effective in controlling advanced disease, with over 50% of patients surviving at the 10-year mark. However, a diverse spectrum of responses exists, and resistance to ADT may emerge over time. This underscores the need to explore innovative treatment strategies for effectively managing prostate cancer progression. Ongoing research endeavors persist in unraveling the complexity of prostate cancer and fostering the development of biologic and innovative approaches, including immunotherapies and targeted therapies. This review aims to provide a valuable synthesis of the dynamic landscape of emerging drug modalities in this context. Interestingly, the complexities posed by prostate cancer not only present a formidable challenge but also serve as a model and an opportunity for translational research and innovative therapies in the field of oncology.

Overexpression of Fibroblast Activation Protein (FAP) in stroma of proliferative inflammatory atrophy (PIA) and primary adenocarcinoma of the prostate

Fibroblast activation protein (FAP) is a serine protease upregulated at sites of tissue remodeling and cancer that represents a promising therapeutic and molecular imaging target. In prostate cancer, studies of FAP expression using tissue microarrays are conflicting, such that its clinical potential is unclear. Furthermore, little is known regarding FAP expression in benign prostatic tissues. Here we demonstrated, using a novel iterative multiplex IHC assay in standard tissue sections, that FAP was nearly absent in normal regions, but was increased consistently in regions of proliferative inflammatory atrophy (PIA). In carcinoma, FAP was expressed in all cases, but was highly heterogeneous. High FAP levels were associated with increased pathological stage and cribriform morphology. We verified that FAP levels in cancer correlated with CD163+ M2 macrophage density. In this first report to quantify FAP protein in benign prostate and primary tumors, using standard large tissue sections, we clarify that FAP is present in all primary prostatic carcinomas, supporting its potential clinical relevance. The finding of high levels of FAP within PIA supports the injury/regeneration model for its pathogenesis and suggests that it harbors a protumorigenic stroma. Yet, high levels of FAP in benign regions could lead to false positive FAP-based molecular imaging results in clinically localized prostate cancer.

Prostatic proliferative inflammatory atrophy: welcome to the club†

Single-cell RNA sequencing studies in the human prostate have defined a population of epithelial cells with transcriptional similarities to club cells in the lung. However, the localization of club-like cells in the human prostate, and their relationship to prostate cancer, is poorly understood. In a new article in The Journal of Pathology, RNA in situ hybridization was used to demonstrate that club cell markers are expressed in luminal cells adjacent to inflammation in the peripheral zone of the human prostate, where prostate cancer tends to arise. These club-like cells are commonly found in proliferative inflammatory atrophy (PIA) lesions and express markers consistent with an intermediate epithelial cell-type. Future studies will be needed to understand the functional role of club-like cells in human prostate inflammation, regeneration, and disease. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Convergent alterations in the tumor microenvironment of MYC-driven human and murine prostate cancer

The tissue microenvironment in prostate cancer is profoundly altered. While such alterations have been implicated in driving prostate cancer initiation and progression to aggressive disease, how prostate cancer cells and their precursors mediate those changes is unclear, in part due to the inability to longitudinally study the disease evolution in human tissues. To overcome this limitation, we performed extensive single-cell RNA-sequencing (scRNA-seq) and rigorous molecular pathology of the comparative biology between human prostate cancer and key time points in the disease evolution of a genetically engineered mouse model (GEMM) of prostate cancer. Our studies of human tissues, with validation in a large external data set, revealed that cancer cell-intrinsic activation of MYC signaling was the top up-regulated pathway in human cancers, representing a common denominator across the well-known molecular and pathological heterogeneity of human prostate cancer. Likewise, numerous non-malignant cell states in the tumor microenvironment (TME), including non-cancerous epithelial, immune, and fibroblast cell compartments, were conserved across individuals, raising the possibility that these cell types may be a sequelae of the convergent MYC activation in the cancer cells. To test this hypothesis, we employed a GEMM of prostate epithelial cell-specific MYC activation in two mouse strains. Cell communication network and pathway analyses suggested that MYC oncogene-expressing neoplastic cells, directly and indirectly, reprogrammed the TME during carcinogenesis, leading to the emergence of cascading cell state alterations in neighboring epithelial, immune, and fibroblast cell types that paralleled key findings in human prostate cancer. Importantly, among these changes, the progression from a precursor-enriched to invasive-cancer-enriched state was accompanied by a cell-intrinsic switch from pro-immunogenic to immunosuppressive transcriptional programs with coinciding enrichment of immunosuppressive myeloid and Treg cells in the immune microenvironment. These findings implicate activation of MYC signaling in reshaping convergent aspects of the TME of prostate cancer as a common denominator across the otherwise well-documented molecular heterogeneity of human prostate cancer.