Sox2 is necessary for androgen ablation-induced neuroendocrine differentiation from Pten null Sca-1+ prostate luminal cells

Nuclear receptor TLX functions to promote cancer stemness and EMT in prostate cancer via its direct transactivation of CD44 and stem cell-regulatory transcription factors

BACKGROUND

Prostate cancer stem cells (PCSCs) play crucial roles in therapy-resistance and metastasis in castration-resistant prostate cancer (CRPC). Certain functional link between cancer stemness and epithelial-mesenchymal transition (EMT) is involved in CRPC. However, up-stream regulators controlling these two processes in PCSCs are still poorly understood. Recently, we have shown that orphan nuclear receptor TLX can promote tumour initiation and progression in CRPC by repressing androgen receptor and oncogene-induced senescence.

METHODS

PCSCs were isolated from various prostate cancer cell lines and clinical tumour tissues using multiple methods for various in vitro and in vivo oncogenic growth analyses. Direct targets of TLX involved in stemness and EMT regulation were determined by specific reporter gene assays and ligand-driven modulation of TLX activity.

RESULTS

PCSCs isolated from various sources exhibited increased expression of TLX. Functional and molecular characterisation showed that TLX could function to promote cancer stemness and EMT in prostate cancer cells via its direct transactivation of CD44, SOX2, POU5F1 and NANOG, which share certain functional crosstalk in these two cellular processes.

CONCLUSIONS

TLX could act as a key up-stream regulator in transcriptional control of stemness and EMT in PCSCs, which contribute to their tumorigenicity, castration-resistance and metastasis potentials in advanced prostate cancer.

Neuroendocrine transdifferentiation in human cancer: molecular mechanisms and therapeutic targets

Neuroendocrine transdifferentiation (NEtD), also commonly referred to as lineage plasticity, emerges as an acquired resistance mechanism to molecular targeted therapies in multiple cancer types, predominately occurs in metastatic epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer treated with EGFR tyrosine kinase inhibitors and metastatic castration-resistant prostate cancer treated with androgen receptor targeting therapies. NEtD tumors are the lethal cancer histologic subtype with unfavorable prognosis and limited treatment. A comprehensive understanding of molecular mechanism underlying targeted-induced plasticity could greatly facilitate the development of novel therapies. In the past few years, increasingly elegant studies indicated that NEtD tumors share key the convergent genomic and phenotypic characteristics irrespective of their site of origin, but also embrace distinct change and function of molecular mechanisms. In this review, we provide a comprehensive overview of the current understanding of molecular mechanism in regulating the NEtD, including genetic alterations, DNA methylation, histone modifications, dysregulated noncoding RNA, lineage-specific transcription factors regulation, and other proteomic alterations. We also provide the current management of targeted therapies in clinical and preclinical practice.

Treatment-induced stemness and lineage plasticity in driving prostate cancer therapy resistance

Most human cancers are heterogeneous consisting of cancer cells at different epigenetic and transcriptional states and with distinct phenotypes, functions, and drug sensitivities. This inherent cancer cell heterogeneity contributes to tumor resistance to clinical treatment, especially the molecularly targeted therapies such as tyrosine kinase inhibitors (TKIs) and androgen receptor signaling inhibitors (ARSIs). Therapeutic interventions, in turn, induce lineage plasticity (also called lineage infidelity) in cancer cells that also drives therapy resistance. In this Perspective, we focus our discussions on cancer cell lineage plasticity manifested as treatment-induced switching of epithelial cancer cells to basal/stem-like, mesenchymal, and neural lineages. We employ prostate cancer (PCa) as the prime example to highlight ARSI-induced lineage plasticity during and towards development of castration-resistant PCa (CRPC). We further discuss how the tumor microenvironment (TME) influences therapy-induced lineage plasticity. Finally, we offer an updated summary on the regulators and mechanisms driving cancer cell lineage infidelity, which should be therapeutically targeted to extend the therapeutic window and improve patients' survival.

Integrated single-cell analysis defines the epigenetic basis of castration-resistant prostate luminal cells

Understanding prostate response to castration and androgen receptor signaling inhibitors (ARSI) is critical to improving long-term prostate cancer (PCa) patient survival. Here, we use a multi-omics approach on 229,794 single cells to create a mouse single-cell reference atlas for interpreting mouse prostate biology and castration response. Our reference atlas refines single-cell annotations and provides a chromatin context, which, when coupled with mouse lineage tracing, demonstrates that castration-resistant luminal cells are distinct from the pre-existent urethra-proximal stem/progenitor cells. Molecular pathway analysis and therapeutic studies further implicate AP1 (JUN/FOS), WNT/β-catenin, FOXQ1, NF-κB, and JAK/STAT pathways as major drivers of castration-resistant luminal populations with relevance to human PCa. Our datasets, which can be explored through an interactive portal (https://visportal.roswellpark.org/data/tang/), can aid in developing combination treatments with ARSI for advanced PCa patients.

Cellular plasticity in reprogramming, rejuvenation and tumorigenesis: a pioneer TF perspective

The multistep process of in vivo reprogramming, mediated by the transcription factors (TFs) Oct4, Sox2, Klf4, and c-Myc (OSKM), holds great promise for the development of rejuvenating and regenerative strategies. However, most of the approaches developed so far are accompanied by a persistent risk of tumorigenicity. Here, we review the groundbreaking effects of in vivo reprogramming with a particular focus on rejuvenation and regeneration. We discuss how the activity of pioneer TFs generates cellular plasticity that may be critical for inducing not only reprogramming and regeneration, but also cancer initiation. Finally, we highlight how a better understanding of the uncoupled control of cellular identity, plasticity, and aging during reprogramming might pave the way to the development of rejuvenating/regenerating strategies in a nontumorigenic manner.

AKAP2-anchored protein phosphatase 1 controls prostatic neuroendocrine carcinoma cell migration and invasion

Prostate cancer (PC) is the second leading cause of cancer-related death in men. The growth of primary prostate cancer cells relies on circulating androgens and thus the standard therapy for the treatment of localized and advanced PC is the androgen deprivation therapy. Prostatic neuroendocrine carcinoma (PNEC) is an aggressive and highly metastatic subtype of prostate cancer, which displays poor prognosis and high lethality. Most of PNECs develop from prostate adenocarcinoma in response to androgen deprivation therapy, however the mechanisms involved in this transition and in the elevated biological aggressiveness of PNECs are poorly defined. Our current findings indicate that AKAP2 expression is dramatically upregulated in PNECs as compared to non-cancerous prostate tissues. Using a PNEC cell model, we could show that AKAP2 is localized both intracellularly and at the cell periphery where it colocalizes with F-actin. AKAP2 and F-actin interact directly through a newly identified actin-binding domain located on AKAP2. RNAi-mediated silencing of AKAP2 promotes the phosphorylation and deactivation of cofilin, a protein involved in actin turnover. This effect correlates with a significant reduction in cell migration and invasion. Co-immunoprecipitation experiments and proximity ligation assays revealed that AKAP2 forms a complex with the catalytic subunit of protein phosphatase 1 (PP1) in PNECs. Importantly, AKAP2-mediated anchoring of PP1 to the actin cytoskeleton regulates cofilin dephosphorylation and activation, which, in turn, enhances F-actin dynamics and favors migration and invasion. In conclusion, this study identified AKAP2 as an anchoring protein overexpressed in PNECs that controls cancer cell invasive properties by regulating cofilin phosphorylation.

ASCL1 is activated downstream of the ROR2/CREB signaling pathway to support lineage plasticity in prostate cancer

Lineage plasticity is a form of therapy-induced drug resistance. In prostate cancer, androgen receptor (AR) pathway inhibitors potentially lead to the accretion of tumor relapse with loss of AR signaling and a shift from a luminal state to an alternate program. However, the molecular and signaling mechanisms orchestrating the development of lineage plasticity under the pressure of AR-targeted therapies are not fully understood. Here, a survey of receptor tyrosine kinases (RTKs) identifies ROR2 as the top upregulated RTK following AR pathway inhibition, which feeds into lineage plasticity by promoting stem-cell-like and neuronal networks. Mechanistically, ROR2 activates the ERK/CREB signaling pathway to modulate the expression of the lineage commitment transcription factor ASCL1. Collectively, our findings nominate ROR2 as a potential therapeutic target to reverse the ENZ-induced plastic phenotype and potentially re-sensitize tumors to AR pathway inhibitors.

Targeting ITGB4/SOX2-driven lung cancer stem cells using proteasome inhibitors

This study investigates the role of integrin β4 (ITGB4) and stemness-associated factor SOX2 in platinum resistance in lung squamous cell carcinoma (LUSC). The expression of SOX2 and ITGB4 is found to be high in all LUSC subtypes, but the impact of ITGB4 expression on overall patient survival varies by subtype. Cancer stem cells (CSCs) isolated from LUSC patients were found to be resistant to cisplatin, but knocking down ITGB4 or SOX2 sensitized them to cisplatin. Carfilzomib (CFZ) synergized with cisplatin and suppressed CSC growth by inhibiting ITGB4 and SOX2 expression. Additionally, CFZ was found to inhibit SOX2 expression epigenetically by inhibiting histone acetylation at the SOX2 promoter site. CFZ also suppressed the growth of SOX2-dependent small cell lung cancer cells in vitro and in vivo. The study highlights the unique function of CFZ as a transcriptional suppressor of SOX2, independent of its proteasome inhibitory function.

Autocrine amphiregulin signaling sustains castration-resistant Ly6d+ prostate cancer cells

Mechanisms underlying the development of castration-resistant prostate cancer (CRPC) remain incompletely understood. A recent study by Steiner et al. shows that Ly6d⁺ prostate tumor cells survive androgen deprivation through an autocrine amphiregulin signaling pathway.

Defining cellular population dynamics at single-cell resolution during prostate cancer progression

Advanced prostate malignancies are a leading cause of cancer-related deaths in men, in large part due to our incomplete understanding of cellular drivers of disease progression. We investigate prostate cancer cell dynamics at single-cell resolution from disease onset to the development of androgen independence in an in vivo murine model. We observe an expansion of a castration-resistant intermediate luminal cell type that correlates with treatment resistance and poor prognosis in human patients. Moreover, transformed epithelial cells and associated fibroblasts create a microenvironment conducive to pro-tumorigenic immune infiltration, which is partially androgen responsive. Androgen-independent prostate cancer leads to significant diversification of intermediate luminal cell populations characterized by a range of androgen signaling activity, which is inversely correlated with proliferation and mRNA translation. Accordingly, distinct epithelial populations are exquisitely sensitive to translation inhibition, which leads to epithelial cell death, loss of pro-tumorigenic signaling, and decreased tumor heterogeneity. Our findings reveal a complex tumor environment largely dominated by castration-resistant luminal cells and immunosuppressive infiltrates.

Stromal FOXF2 suppresses prostate cancer progression and metastasis by enhancing antitumor immunity

Cancer-associated fibroblasts (CAFs) mediate an immunosuppressive effect, but the underlying mechanism remains incompletely defined. Here we show that increasing prostatic stromal Foxf2 suppresses the growth and progression of both syngeneic and autochthonous mouse prostate cancer models in an immunocompetent context. Mechanistically, Foxf2 moderately attenuates the CAF phenotype and transcriptionally downregulates Cxcl5, which diminish the immunosuppressive myeloid cells and enhance T cell cytotoxicity. Increasing prostatic stromal Foxf2 sensitizes prostate cancer to the immune checkpoint blockade therapies. Augmenting lung stromal Foxf2 also mediates an immunosuppressive milieu and inhibits lung colonization of prostate cancer. FOXF2 is expressed higher in the stroma of human transition zone (TZ) than peripheral zone (PZ) prostate. The stromal FOXF2 expression level in primary prostate cancers inversely correlates with the Gleason grade. Our study establishes Foxf2 as a stromal transcription factor modulating the tumor immune microenvironment and potentially explains why cancers are relatively rare and indolent in the TZ prostate.

Lin28 Regulates Cancer Cell Stemness for Tumour Progression

Tumours develop therapy resistance through complex mechanisms, one of which is that cancer stem cell (CSC) populations within the tumours present self-renewable capability and phenotypical plasticity to endure therapy-induced stress conditions and allow tumour progression to the therapy-resistant state. Developing therapeutic strategies to cope with CSCs requires a thorough understanding of the critical drivers and molecular mechanisms underlying the aforementioned processes. One such hub regulator of stemness is Lin28, an RNA-binding protein. Lin28 blocks the synthesis of let-7, a tumour-suppressor microRNA, and acts as a global regulator of cell differentiation and proliferation. Lin28also targets messenger RNAs and regulates protein translation. In this review, we explain the role of the Lin28/let-7 axis in establishing stemness, epithelial-to-mesenchymal transition, and glucose metabolism reprogramming. We also highlight the role of Lin28 in therapy-resistant prostate cancer progression and discuss the emergence of Lin28-targeted therapeutics and screening methods.

Lineage plasticity in prostate cancer: Looking beyond intrinsic alterations

Emergence of small cell prostate cancer is linked to the plasticity of tumour cells and avoidance of environmental pressures. This process is thought to be reversable, however to-date evidence of this has been demonstrated in small-cell prostate cancer. To study the plasticity of prostate tumours, we look to clinical cohorts of patients covering the spectra of malignancy subtypes and utilise in vitro and in vivo models of disease progression. Current models have assisted in the understanding of the extremities of this plasticity, elucidating internal mechanisms and adaptations to stressors through transition to altered cell states. By interrogating the tumour microenvironment and earlier time points, we are beginning to form a deeper understanding of the full spectra of tumour plasticity. It could be proffered that this deeper understanding will lead to better patient outcome, with earlier interventions more likely to reverse plasticity and prevent trans-differentiation to the aggressive, small cell phenotype.

Ectopic JAK-STAT activation enables the transition to a stem-like and multilineage state conferring AR-targeted therapy resistance

Emerging evidence indicates that various cancers can gain resistance to targeted therapies by acquiring lineage plasticity. Although various genomic and transcriptomic aberrations correlate with lineage plasticity, the molecular mechanisms enabling the acquisition of lineage plasticity have not been fully elucidated. We reveal that Janus kinase (JAK)-signal transducer and activator of transcription (STAT) signaling is a crucial executor in promoting lineage plasticity-driven androgen receptor (AR)-targeted therapy resistance in prostate cancer. Importantly, ectopic JAK-STAT activation is specifically required for the resistance of stem-like subclones expressing multilineage transcriptional programs but not subclones exclusively expressing the neuroendocrine-like lineage program. Both genetic and pharmaceutical inhibition of JAK-STAT signaling resensitizes resistant tumors to AR-targeted therapy. Together, these results suggest that JAK-STAT are compelling therapeutic targets for overcoming lineage plasticity-driven AR-targeted therapy resistance.

Transcriptomic Signature and Growth Factor Regulation of Castration-Tolerant Prostate Luminal Progenitor Cells

Background: The molecular and cellular mechanisms that drive castration-resistant prostate cancer (CRPC) remain poorly understood. LSCmed cells defines an FACS-enriched population of castration-tolerant luminal progenitor cells that has been proposed to promote tumorigenesis and CRPC in Pten-deficient mice. The goals of this study were to assess the relevance of LSCmed cells through the analysis of their molecular proximity with luminal progenitor-like cell clusters identified by single-cell (sc)RNA-seq analyses of mouse and human prostates, and to investigate their regulation by in silico-predicted growth factors present in the prostatic microenvironment. Methods: Several bioinformatic pipelines were used for pan-transcriptomic analyses. LSCmed cells isolated by cell sorting from healthy and malignant mouse prostates were characterized using RT-qPCR, immunofluorescence and organoid assays. Results: LSCmed cells match (i) mouse luminal progenitor cell clusters identified in scRNA-seq analyses for which we provide a common 15-gene signature including the previously identified LSCmed marker Krt4, and (ii) Club/Hillock cells of the human prostate. This transcriptional overlap was maintained in cancer contexts. EGFR/ERBB4, IGF-1R and MET pathways were identified as autocrine/paracrine regulators of progenitor, proliferation and differentiation properties of LSCmed cells. The functional redundancy of these signaling pathways allows them to bypass the effect of receptor-targeted pharmacological inhibitors. Conclusions: Based on transcriptomic profile and pharmacological resistance to monotherapies that failed in CRPC patients, this study supports LSCmed cells as a relevant model to investigate the role of castration-tolerant progenitor cells in human prostate cancer progression.

The Role of Epigenetic Change in Therapy-Induced Neuroendocrine Prostate Cancer Lineage Plasticity

The androgen receptor (AR) signaling pathway is critical for growth and differentiation of prostate cancer cells. For that reason, androgen deprivation therapy with medical or surgical castration is the principal treatment for metastatic prostate cancer. More recently, new potent AR signaling inhibitors (ARSIs) have been developed. These drugs improve survival for men with metastatic castration-resistant prostate cancer (CRPC), the lethal form of the disease. However, ARSI resistance is nearly universal. One recently appreciated resistance mechanism is lineage plasticity or switch from an AR-driven, luminal differentiation program to an alternate differentiation program. Importantly, lineage plasticity appears to be increasing in incidence in the era of new ARSIs, strongly implicating AR suppression in this process. Lineage plasticity and shift from AR-driven tumors occur on a continuum, ranging from AR-expressing tumors with low AR activity to AR-null tumors that have activation of alternate differentiation programs versus the canonical luminal program found in AR-driven tumors. In many cases, AR loss coincides with the activation of a neuronal program, most commonly exemplified as therapy-induced neuroendocrine prostate cancer (t-NEPC). While genetic events clearly contribute to prostate cancer lineage plasticity, it is also clear that epigenetic events-including chromatin modifications and DNA methylation-play a major role. Many epigenetic factors are now targetable with drugs, establishing the importance of clarifying critical epigenetic factors that promote lineage plasticity. Furthermore, epigenetic marks are readily measurable, demonstrating the importance of clarifying which measurements will help to identify tumors that have undergone or are at risk of undergoing lineage plasticity. In this review, we discuss the role of AR pathway loss and activation of a neuronal differentiation program as key contributors to t-NEPC lineage plasticity. We also discuss new epigenetic therapeutic strategies to reverse lineage plasticity, including those that have recently entered clinical trials.

Understanding and targeting prostate cancer cell heterogeneity and plasticity

Prostate cancer (PCa) is a prevalent malignancy that occurs primarily in old males. Prostate tumors in different patients manifest significant inter-patient heterogeneity with respect to histo-morphological presentations and molecular architecture. An individual patient tumor also harbors genetically distinct clones in which PCa cells display intra-tumor heterogeneity in molecular features and phenotypic marker expression. This inherent PCa cell heterogeneity, e.g., in the expression of androgen receptor (AR), constitutes a barrier to the long-term therapeutic efficacy of AR-targeting therapies. Furthermore, tumor progression as well as therapeutic treatments induce PCa cell plasticity such that AR-positive PCa cells may turn into AR-negative cells and prostate tumors may switch lineage identity from adenocarcinomas to neuroendocrine-like tumors. This induced PCa cell plasticity similarly confers resistance to AR-targeting and other therapies. In this review, I first discuss PCa from the perspective of an abnormal organ development and deregulated cellular differentiation, and discuss the luminal progenitor cells as the likely cells of origin for PCa. I then focus on intrinsic PCa cell heterogeneity in treatment-naïve tumors with the presence of prostate cancer stem cells (PCSCs). I further elaborate on PCa cell plasticity induced by genetic alterations and therapeutic interventions, and present potential strategies to therapeutically tackle PCa cell heterogeneity and plasticity. My discussions will make it clear that, to achieve enduring clinical efficacy, both intrinsic PCa cell heterogeneity and induced PCa cell plasticity need to be targeted with novel combinatorial approaches.

Prostate organogenesis

Prostate organogenesis begins during embryonic development and continues through puberty when the prostate becomes an important exocrine gland of the male reproductive system. The specification and growth of the prostate is regulated by androgens and is largely a result of cell-cell communication between the epithelium and mesenchyme. The fields of developmental and cancer biology have long been interested in prostate organogenesis because of its relevance for understanding prostate diseases, and research has expanded in recent years with the advent of novel technologies, including genetic-lineage tracing, single-cell RNA sequencing and organoid culture methods, that have provided important insights into androgen regulation, epithelial cell origins and cellular heterogeneity. We discuss these findings, putting them into context with what is currently known about prostate organogenesis.

Paracrine Wnt signaling is necessary for prostate epithelial proliferation

INTRODUCTION

The Wnt proteins play key roles in the development, homeostasis, and disease progression of many organs including the prostate. However, the spatiotemporal expression patterns of Wnt proteins in prostate cell lineages at different developmental stages and in prostate cancer remain inadequately characterized.

METHODS

We isolated the epithelial and stromal cells in the developing and mature mouse prostate by flow cytometry and determined the expression levels of Wnt ligands. We used Visium spatial gene expression analysis to determine the spatial distribution of Wnt ligands in the mouse prostatic glands. Using laser-capture microscopy in combination with gene expression analysis, we also determined the expression patterns of Wnt signaling components in stromal and cancer cells in advanced human prostate cancer specimens. To investigate how the stroma-derived Wnt ligands affect prostate development and homeostasis, we used a Col1a2-CreERT2 mouse model to disrupt the Wnt transporter Wntless specifically in prostate stromal cells.

RESULTS

We showed that the prostate stromal cells are a major source of several Wnt ligands. Visium spatial gene expression analysis revealed a distinct spatial distribution of Wnt ligands in the prostatic glands. We also showed that Wnt signaling components are highly expressed in the stromal compartment of primary and advanced human prostate cancer. Blocking stromal Wnt secretion attenuated prostate epithelial proliferation and regeneration but did not affect cell survival and lineage maintenance.

DISCUSSION

Our study demonstrates a critical role of stroma-derived Wnt ligands in prostate development and homeostasis.

Aging of the progenitor cells that initiate prostate cancer

Many organs experience a loss of tissue mass and a decline in regenerative capacity during aging. In contrast, the prostate continues to grow in volume. In fact, age is the most important risk factor for prostate cancer. However, the age-related factors that influence the composition, morphology and molecular features of prostate epithelial progenitor cells, the cells-of-origin for prostate cancer, are poorly understood. Here, we review the evidence that prostate luminal progenitor cells are expanded with age. We explore the age-related changes to the microenvironment that may influence prostate epithelial cells and risk of transformation. Finally, we raise a series of questions about models of aging and regulators of prostate aging which need to be addressed. A fundamental understanding of aging in the prostate will yield critical insights into mechanisms that promote the development of age-related prostatic disease.

The heterogeneity of prostate cancers lacking AR activity will require diverse treatment approaches

The use of androgen deprivation therapy and second-line anti-androgens in prostate cancer has led to the emergence of tumors employing multiple androgen receptor (AR)-dependent and AR-independent mechanisms to resist AR-targeted therapies in castration-resistant prostate cancer (CRPC). While the AR signaling axis remains the cornerstone for therapeutic development in CRPC, a clearer understanding of the heterogeneous biology of CRPC tumors is needed for innovative treatment strategies. In this review, we discuss the characteristics of CRPC tumors that lack AR activity and the temporal and spatial considerations for the conversion of an AR-dependent to an AR-independent tumor type. We describe the more prevalent treatment-emergent phenotypes arising in the CRPC disease continuum, including amphicrine, AR-low, double-negative, neuroendocrine and small cell phenotypes. We discuss the association between the loss of AR activity and tumor plasticity with a focus on the roles of transcription factors like SOX2, DNA methylation, alternative splicing, and the activity of epigenetic modifiers like EZH2, BRD4, LSD1, and the nBAF complex in conversion to a neuroendocrine or small cell phenotype in CRPC. We hypothesize that only a subset of CRPC tumors have the propensity for tumor plasticity and conversion to the neuroendocrine phenotype and outline how we might target these plastic and emergent phenotypes in CRPC. In conclusion, we assess the current and future avenues for treatment and determine that the heterogeneity of CRPCs lacking AR activity will require diverse treatment approaches.

The role of Trop2 in prostate cancer: an oncogene, biomarker, and therapeutic target

Prostate cancer remains the second leading cause of cancer-associated deaths amongst American men. Trop2, a cell surface glycoprotein, correlates with poor clinical outcome and is highly expressed in metastatic, treatment-resistant prostate cancer. High levels of Trop2 are prognostic for biochemical recurrence. Trop2 regulates tumor growth and metastatic ability of prostate cancer. Moreover, overexpression of Trop2 drives the transdifferentiation to neuroendocrine phenotype in prostate cancer. In addition, Trop2 is overexpressed across epithelial cancers and has emerged as a promising therapeutic target in various solid epithelial cancers. The FDA (Food and Drug Administration) recently approved the use of a Trop2-targeting ADC (antibody-drug conjugate), Sacituzumab Govitecan (IMMU-132), for metastatic, triple-negative breast cancer with at least two prior therapies. Here, we review the role of Trop2 in prostate tumorigenesis and its potential as a promising biomarker and therapeutic target for prostate cancer.