Clinical implications of PTEN loss in prostate cancer

CHD1 dysregulation in cancer: bridging chromatin instability, therapy resistance, and immune evasion

Chromodomain-Helicase-DNA-binding protein 1 (CHD1) is a central regulator of chromatin dynamics, profoundly influencing gene expression, DNA repair, and genomic stability. This review critically explores CHD1's role in cancer biology, emphasizing its complex, context-dependent functions. In prostate cancer, CHD1 acts as both a tumour suppressor and a facilitator of neuroendocrine differentiation, with its loss linked to aggressive phenotypes, resistance to androgen receptor therapies, and synthetic lethality with PTEN loss. Beyond prostate cancer, CHD1 is implicated in breast, ovarian, and hematological cancers, where it modulates chromatin accessibility, transcription regulation, and therapy resistance. Despite its promise as a biomarker and therapeutic target, CHD1 presents challenges due to its dual roles and cancer-specific effects. The review also highlights critical gaps, including the need for high-resolution studies on CHD1's interactions with immune pathways, synthetic lethality mechanisms, and chromatin remodelling in treatment resistance. Leveraging CHD1's molecular complexities could show the way for innovative diagnostic and therapeutic strategies in cancer, but its role in non-prostate cancers remains underexplored, warranting further investigation.

Prognostic value of PARP1 and PARP2 copy number alterations in prostate cancer

PARP1/2 have overlapping yet non-redundant biological functions in DNA repair and AR-transcriptional regulation. Studies on PARP alterations in human tumors have yielded conflicting results. In prostate cancer (PCa), PARP1/2 protein overexpression has been related to androgen deprivation therapy (ADT) resistance, biochemical recurrence, and progression to metastases. PARP inhibitors (PARPi) have been approved for treating metastatic castration-resistant PCa with homologous recombination repair (HRR) gene mutations. However, the significance of PARP1/2 genomic alterations is not fully studied. We aimed to analyze PARP1/2 alterations in PCa, to assess their value as prognostic markers, and to explore their relevance for potential therapeutic stratification. PARP1/2 copy number status was evaluated in 121 PCa primary tumors through real time PCR. In 29 of them, a regional pelvic lymph node (RLN) involvement was also analyzed. BRCA1/2 somatic mutations were analyzed in 24 PCa. Relationship with clinicopathological features, progression to metastases, and PSA recurrence was assessed. PARP1 loss and PARP2 gain were detected in 34.7% and 32.2% of primary tumors, respectively, with a high frequency of co-occurrence (p<0.001). Both alterations were statistically associated with locally-advanced disease at diagnosis (p=0.036; p=0.006), metastatic dissemination (p=0.014; p=0.003), and other aggressive clinicopathological characteristics (as presence of Gleason pattern 5, high-grade, and high-stage). Cases with exclusive PARP2 gain had the shortest time to PSA recurrence, while double wt patients displayed the best outcome (p=0.007). In 29 paired primary tumors and RLN involvement, PARP1 loss showed strong concordance (p=0.001), whereas PARP2 gain did not (p=0.411). In conclusion, loss of PARP1 and gain of PARP2 show strong co-occurrence, and are associated with clinicopathological characteristics of aggressiveness. PARP2 alterations appear to have a particularly significant impact on disease prognosis. Furthermore, these data suggest that the analysis of PARP1/2 copy number status could be useful to predict PCa outcome. Its role on therapy warrants further evaluation.

Key considerations for a prostate cancer mRNA vaccine

Prostate cancer has the second highest cancer mortality rate in the UK in males. Early prostate cancer is typically asymptomatic, with diagnosis at a locally advanced or metastatic stage. In addition, the inherent heterogeneity of prostate cancer tumours differs significantly in terms of genetic, molecular, and histological features. The successful treatment of prostate cancer is therefore exceedingly challenging. Immunotherapies, particularly therapeutic vaccines, have been widely used in preclinical and clinical studies to treat various cancers. Sipuleucel-T was the first cancer vaccine approved by the FDA for the treatment of asymptomatic or minimally symptomatic metastatic castration-resistant prostate cancer (mCRPC), ushering in a new era of immunotherapy. In this review, the latest immunotherapy strategies for prostate cancer are considered with key tumour-associated antigens (TAA) and tumour-specific antigens (TSA) highlighted. The key components of mRNA vaccines include in vitro transcription, stability, and immunogenicity. Finally, strategies to circumvent in vivo mRNA degradation and approaches to optimise in vitro transcription (IVT) process are also discussed.

The Benefit of Combining Docetaxel with Androgen Deprivation Therapy in Localized and Metastatic Hormone-sensitive Prostate Cancer is Predicted by ERG Expression: An Analysis of Two GETUG Phase 3 Trials

BACKGROUND AND OBJECTIVE

Docetaxel has become a standard component of care for advanced prostate cancer (PC); however, its benefits are not universal among patients. A subset of PC cases exhibit TMPRSS2-ERG gene fusion, resulting in ERG overexpression in tumors. Our aim was to assess biomarkers for docetaxel efficacy in men with hormone-sensitive PC (HSPC).

METHODS

Pretreatment prostate biopsies were obtained from participants in two randomized phase 3 clinical trials investigating docetaxel in high-risk localized PC (GETUG 12) and metastatic HSPC (GETUG 15). Immunohistochemistry staining for Ki67, PTEN, RB, and phosphorylated RB was conducted for GETUG 12 samples, and ERG staining for GETUG 12 and GETUG 15 samples. We examined biomarker association with outcomes using univariate and multivariable analyses adjusted for other validated prognostic factors.

KEY FINDINGS AND LIMITATIONS

Among GETUG 12 patients, Ki67 was associated with a worse relapse-free survival (RFS; hazard ratio [HR] 1.72; p = 0.0092). A pooled analysis for the two trials (pinteraction = 0.056) revealed that docetaxel-based chemotherapy improved failure-free survival for patients with ERG-positive cancer (HR 0.58; p = 0.03), but not patients with ERG-negative cancer (HR 1.08; p = 0.72). In the ERG-positive subgroup in GETUG 12 (high-risk localized PC), median RFS was 7.79 yr with androgen deprivation therapy (ADT) alone, and was not reached with ADT + docetaxel. In the ERG-negative subgroup, median progression-free survival (mPFS) was 7.79 yr with ADT alone versus 7.08 yr with ADT + docetaxel. In the ERG-positive subgroup in GETUG 15 (metastatic HSPC), mPFS was 10.7 mo with ADT alone versus 18.8 mo with ADT + docetaxel. In the ERG-negative subgroup, mPFS was 10.6 mo with ADT alone versus 13.2 mo with ADT + docetaxel.

CONCLUSIONS AND CLINICAL IMPLICATIONS

Ki67 may serve as a prognostic factor in HSPC, while ERG expression appears to predict a response to docetaxel in both high-risk localized and metastatic HSPC.

PATIENT SUMMARY

We assessed factors that could predict outcomes after docetaxel chemotherapy in patients with advanced prostate cancer. We found that expression of a protein called ERG can predict a good response to docetaxel in these patients.

Targeting the TLK1-MK5 Axis Suppresses Prostate Cancer Metastasis

Background: The spread of metastatic prostate cancer (PCa) is responsible for the majority of PCa-related deaths, yet the precise mechanisms driving this process remain unclear. We have identified a novel interaction between two distinct promotility factors, tousled-like kinase 1 (TLK1) and MAPK-activated protein kinase 5 (MK5), which triggers a signaling cascade that promotes metastasis. In PCa, the TLK1-MK5 pathway may play a critical role, as androgen deprivation therapy (ADT) has been linked to increased expression of both TLK1 and MK5 in metastatic patients linked with poor survival. Objectives: In this study, we directly examined the effects of disrupting the TLK1>MK5 axis on the motility, invasiveness, and metastatic potential of PCa cells. Methods: To establish this, we used both pharmacologic and systemic approaches with genetically engineered mouse models and the use of IVIS. Results: The results of targeting the TLK1>MK5 axis support the notion that this axis is essential for the spread of metastatic cells and the development of age-related metastases.

The kinase PLK1 promotes Hedgehog signaling-dependent resistance to the antiandrogen enzalutamide in metastatic prostate cancer

Enzalutamide, a second-generation androgen receptor inhibitor (also known as an antiandrogen), is used to treat patients with metastatic castration-resistant prostate cancer (CRPC). Tumors often acquire resistance to enzalutamide. Tumor progression and enzalutamide resistance are associated with decreased abundance of the tumor suppressor PDCD4. In normal dividing cells, PDCD4 abundance is low when that of the kinase PLK1 is high. In this study, we found that PLK1 acted on PDCD4 to promote enzalutamide resistance in CRPC cells in culture and in mice via a mechanism that revealed an effective combination therapy. PLK1 phosphorylated PDCD4 at Ser239, leading to its degradation and consequently inducing the transcriptional activation of Hedgehog (Hh) signaling by c-MYC. Hh signaling supports tumor cell proliferation and stemness by inducing the enzyme UDP-glucuronosyltransferase 2B15 (UGT2B15), which promotes the metabolic clearance of drugs and steroid hormones. Thus, this pathway may circumvent androgen receptor dependence, thereby reducing cellular sensitivity to enzalutamide. Knocking down UGT2B15 enhanced enzalutamide-induced cell apoptosis and growth arrest in a PDCD4-dependent manner. Combining enzalutamide with the clinically approved Hh pathway inhibitor vismodegib inhibited cell growth and promoted apoptosis in enzalutamide-resistant cell cultures and xenografts in vivo. Our findings reveal a mechanism of PLK1-mediated enzalutamide resistance and suggest a potential therapeutic strategy to overcome this resistance in prostate cancer.

Exploring therapeutic applications of PTEN, TMPRSS2:ERG fusion, and tumour molecular subtypes in prostate cancer management

Background

Prostate cancer is defined by the suppression of genes that suppress tumours and the activation of proto-oncogenes. These are the hallmarks of prostate cancer, and they have been linked to numerous genomic variations, which lead to unfavourable treatment outcomes. Prostate cancer can be categorised into various risk groups of tumour molecular subtypes grounded in the idea of genomic structural variations connected to TMPRSS2:ERG fusion and loss of PTEN. Research suggests that certain genomic alterations may be more prevalent or exhibit different patterns in prostate cancer tumours across populations. Studies have reported a higher frequency of PTEN loss and TMPRSS2:ERG fusion in prostate tumours of Black/African American men, which may contribute to the more aggressive nature of the disease in this population. Thus, therapeutically important information can be obtained from these structural variations, including correlations with poor prognosis and disease severity.

Methods

Peer-reviewed articles from 1998 to 2024 were sourced from PubMed and Google Scholar. During the review process, the following search terms were employed: "Tumour suppressor genes OR variations OR alterations OR oncogenes OR diagnostics OR ethnicity OR biomarkers OR prostate cancer genomics OR prostate cancer structural variations OR tumour and molecular subtypes OR therapeutic implications OR immunotherapy OR immunogenetics."

Results

There was a total of 13,012 results for our search query: 5,903 publications from Google Scholar with the patent and citation unchecked filer options, and 7127 articles from PubMed with the abstract, free full text, and full-text options selected. Unpublished works were not involved. Except for four articles published between 1998 and 1999, all other selected articles published in 2000 and later were considered. However, papers with irrelevant information or redundant or duplicate content were not chosen for this review. Thus, 134 met the inclusion criteria and were ultimately retained for this review.

Conclusion

This review extracted 134 relevant articles about genomic structure variations in prostate cancer. Our findings demonstrate the importance of PTEN and TMPRSS2:ERG fusion and tumour molecular subtyping in prostate cancer precision medicine.

Incidental Brain Metastases From Prostate Cancer Diagnosed With PSMA PET/CT and MRI: A Case Series and Literature Review

BACKGROUND

Brain metastases (BMETS) from prostate cancer are rare. Hence, brain imaging in neurologically asymptomatic patients with advanced prostate cancer (aPC) is not routinely performed. Prostate-specific membrane antigen (PSMA) PET/CT uses a radiotracer that binds to prostate cancer epithelial cells and is FDA-approved for initial staging for high-risk prostate cancer, detecting prostate cancer recurrence, and determining eligibility for radionuclide therapy.

METHODS

We report six patients with asymptomatic BMETS from aPC found on staging PSMA PET/CT or MRI. Along with cranial MRI, PSMA PET/CT may be useful for detecting asymptomatic intracranial metastasis in select patients with prostate cancer.

RESULTS

Brain metastases were diagnosed in four patients by staging PSMA PET/CT scan-three after systemic disease progression and one during routine surveillance. In two other patients, BMETS were detected using MRI despite negative PSMA PET/CT for brain lesions. All were neurologically asymptomatic. Three patients had undetectable serum prostate-specific antigen (PSA) concentrations; one had neuroendocrine differentiation on histology.

CONCLUSION

In patients with poorly differentiated or neuroendocrine aPC, BMETS may occur without neurologic symptoms and stable PSA. PSMA PET/CT may complement brain MRI for identifying BMETS in these patients.

Extended spectrum of cancers in PTEN hamartoma tumor syndrome

PTEN hamartoma tumor syndrome (PHTS) is associated with increased lifetime risks of breast, thyroid, kidney, endometrial, and colorectal cancers, as well as melanoma (collectively, component cancers). We sought to characterize non-component cancers (NCC) in PHTS. Of 701 research participants with PHTS, 340 (49%) had cancer, with 101 (30%) having at least one NCC. Interestingly, 71 (70%) of those with NCC had at least one other PHTS component malignancy. Patients with pathogenic PTEN variants showed higher risks for prostate cancer and soft tissue sarcomas at younger ages than the general population. A literature survey showed independent cases of NCC in PHTS, with PTEN-related molecular changes including second-hit somatic PTEN alterations in a subset of various specimens. We recommend increased awareness regarding NCC in individuals with PHTS, particularly increased risks for prostate cancer and sarcoma. Further studies are needed to define age-related penetrance and accordingly, the appropriate strategies for cancer risk management.

The impact of dysregulation SUMOylation on prostate cancer

Prostate cancer (PCa) remains one of the most common malignancies in men, with its development and progression being governed by complex molecular pathways. SUMOylation, a post-translational modification (PTM) that involves the covalent attachment of small ubiquitin-like modifier (SUMO) proteins to target substrates, has emerged as a critical regulator of various cellular processes such as transcription, DNA repair, cell cycle progression, and apoptosis. Emerging evidence reveals that abnormal SUMOylation may contribute to PCa pathogenesis, and notably, SUMO-associated enzymes are commonly dysregulated in PCa. This review explores the mechanisms by which SUMOylation is implicated in the regulation of key pathways, and summary aberrant expression of SUMO-related enzymes or SUMOylation sites mutations of substrtes in PCa, as well as the therapeutic implications of targeting the SUMO-related enzymes in PCa treatment.

Decoding driver and phenotypic genes in cancer: Unveiling the essence behind the phenomenon

Gray hair, widely regarded as a hallmark of aging. While gray hair is associated with aging, reversing this trait through gene targeting does not alter the fundamental biological processes of aging. Similarly, certain oncogenes (such as CXCR4, MMP-related genes, etc.) can serve as markers of tumor behavior, such as malignancy or prognosis, but targeting these genes alone may not lead to tumor regression. We pioneered the name of this class of genes as "phenotypic genes". Historically, cancer genetics research has focused on tumor driver genes, while genes influencing cancer phenotypes have been relatively overlooked. This review explores the critical distinction between driver genes and phenotypic genes in cancer, using the MAPK and PI3K/AKT/mTOR pathways as key examples. We also discuss current research techniques for identifying driver and phenotypic genes, such as whole-genome sequencing (WGS), RNA sequencing (RNA-seq), RNA interference (RNAi), CRISPR-Cas9, and other genomic screening methods, alongside the concept of synthetic lethality in driver genes. The development of these technologies will help develop personalized treatment strategies and precision medicine based on the characteristics of relevant genes. By addressing the gap in discussions on phenotypic genes, this review significantly contributes to clarifying the roles of driver and phenotypic genes, aiming at advancing the field of targeted cancer therapy.

Cyclin-Dependent Kinase Inhibition in Prostate Cancer: Past, Present, and Future

BACKGROUND

Despite significant progress, prostate cancer remains a leading cause of death. Cyclin-dependent kinase (CDK) 4/6 inhibitors, which are already approved for the treatment of hormone receptor-positive breast cancer, are undergoing extensive testing as monotherapy and in various combinations as a potentially valuable treatment modality in prostate cancer patients. Thus far, a limited number of these studies have published results, which have been largely disappointing.

AREAS COVERED

In this review, we describe the biologic rationale for the use of CDK4/6 inhibitors in prostate cancer, the existing clinical data describing their use in prostate cancer, and ongoing clinical trials of CDK4/6 inhibitors as monotherapy and in combination for the treatment of prostate cancer. In particular, we focus on possible resistance mechanisms that may be particularly relevant in prostate cancer patients, leading to de novo and acquired resistance, and we highlight novel strategies that can overcome this resistance.

CONCLUSIONS

Current clinical trials are actively working to (1) refine the role of CDK4/6 inhibitors in prostate cancer patients; (2) develop new inhibitors of other cell-cycle targets, such as CDK2 and CDK7; and (3) explore novel combination therapies with inhibitors of other relevant pathways, such as PI3K or MAPK. Further genomic subtyping of advanced prostate cancer will likely shed light on the subsets of patients most likely to benefit from cell-cycle-targeted agents.

Overcoming drug resistance in castrate-resistant prostate cancer: current mechanisms and emerging therapeutic approaches

Metastatic castration-resistant prostate cancer (mCRPC) is driven by a complex network of resistance mechanisms against standard-of-care therapies, resulting in poor long-term outcomes. This review offers a uniquely comprehensive and integrative perspective on these resistance pathways, systematically examining both androgen receptor (AR)-dependent factors (including AR overexpression, point mutations, glucocorticoid receptor signaling, splice variants, post-translational modifications, altered coregulators, and intratumoral hormone biosynthesis) and AR-independent pathways (such as neuroendocrine differentiation, lineage plasticity, and alternative growth factor signaling). We also highlight resistance mechanisms influencing immunotherapy, chemotherapy, radiopharmaceutical therapy and targeted therapy. By synthesizing emerging insights across these domains, this review not only clarifies the underlying biology of mCRPC resistance but also identifies key leverage points for more effective interventions. Building on this foundation, we propose a forward-looking framework for overcoming mCRPC drug resistance, emphasizing the importance of biomarker-guided patient selection, combination strategies that simultaneously target multiple resistance mechanisms, and novel therapies under investigation. These recommendations are intended to guide future clinical trial designs and research priorities that move beyond incremental improvements. Ultimately, this comprehensive synthesis aims to serve as a resource for clinicians and researchers to accelerate the development of durable, precision-based treatment strategies in mCRPC.

Unveiling Racial Disparities in Localized Prostate Cancer: A Systems-Level Exploration of the lncRNA Landscape

BACKGROUND/OBJECTIVES

Prostate cancer (PC) is the most common non-cutaneous cancer in men globally, and one which displays significant racial disparities. Men of African descent (AF) are more likely to develop PC and face higher mortality compared to men of European descent (EU). The biological mechanisms underlying these differences remain unclear. Long non-coding RNAs (lncRNAs), recognized as key regulators of gene expression and immune processes, have emerged as potential contributors to these disparities. This study aimed to investigate the regulatory role of lncRNAs in localized PC in AF men relative to those of EU and assess their involvement in immune response and inflammation.

METHODS

A systems biology approach was employed to analyze differentially expressed (DE) lncRNAs and their roles in prostate cancer (PC). Immune-related pathways were investigated through over-representation analysis of lncRNA-mRNA networks. The study also examined the effects of vitamin D supplementation on lncRNA expression in African descent (AF) PC patients, highlighting their potential regulatory roles in immune response and inflammation.

RESULTS

Key lncRNAs specific to AF men were identified, with several being implicated for immune response and inflammatory processes. Notably, 10 out of the top 11 ranked lncRNAs demonstrated strong interactions with immune-related genes. Pathway analysis revealed their regulatory influence on antigen processing and presentation, chemokine signaling, and ribosome pathways, suggesting their critical roles in immune regulation.

CONCLUSIONS

These findings highlight the pivotal role of lncRNAs in PC racial disparities, particularly through immune modulation. The identified lncRNAs may serve as potential biomarkers or therapeutic targets to address racial disparities in PC outcomes.

Pan-cancer analysis of biallelic inactivation in tumor suppressor genes identifies KEAP1 zygosity as a predictive biomarker in lung cancer

The canonical model of tumor suppressor gene (TSG)-mediated oncogenesis posits that loss of both alleles is necessary for inactivation. Here, through allele-specific analysis of sequencing data from 48,179 cancer patients, we define the prevalence, selective pressure for, and functional consequences of biallelic inactivation across TSGs. TSGs largely assort into distinct classes associated with either pan-cancer (Class 1) or lineage-specific (Class 2) patterns of selection for biallelic loss, although some TSGs are predominantly monoallelically inactivated (Class 3/4). We demonstrate that selection for biallelic inactivation can be utilized to identify driver genes in non-canonical contexts, including among variants of unknown significance (VUSs) of several TSGs such as KEAP1. Genomic, functional, and clinical data collectively indicate that KEAP1 VUSs phenocopy established KEAP1 oncogenic alleles and that zygosity, rather than variant classification, is predictive of therapeutic response. TSG zygosity is therefore a fundamental determinant of disease etiology and therapeutic sensitivity.

Unveiling RACK1: a key regulator of the PI3K/AKT pathway in prostate cancer development

The dysregulated PI3K/AKT pathway is pivotal in the onset and progression of various cancers, including prostate cancer. However, targeting this pathway directly poses challenges due to compensatory upregulation of alternative oncogenic pathways. This study focuses on the novel regulatory activity of the Receptor for Activated Protein Kinase (RACK1), a scaffolding/adaptor protein, in governing the PI3K/AKT pathway within prostate cancer. Through a genetic mouse model, our research unveils RACK1's pivotal role in orchestrating AKT activation and the genesis of prostate cancer. RACK1 deficiency hampers AKT activation, effectively impeding prostate tumor formation induced by PTEN and p53 deficiency. Mechanistically, RACK1 facilitates AKT membrane translocation and fosters its interaction with mTORC2, thereby promoting AKT activation and subsequent tumor cell proliferation and tumor formation. Notably, inhibiting AKT activation via RACK1 deficiency does not trigger feedback upregulation of HER3 and androgen receptor (AR) expression and activation, distinguishing it from direct PI3K or AKT targeting. These findings position RACK1 as a critical regulator of the PI3K/AKT pathway and a promising target for curtailing prostate cancer development arising from pathway aberrations.

Effects of long-term treatment with low concentration butylparaben on prostate organoids

Endocrine-disrupting compounds (EDCs), such as butylparaben (BP), which are used as preservatives in food and cosmetics, have been shown to negatively affect male reproductive health. Organs under the control of hormones such as androgens and estrogens, such as the prostate, are vulnerable to EDC stimulation. It is well known that BP can cause hormonal imbalances in the prostate and lead to various prostate diseases. However, studies on the long-term exposure of low-dose BP, which is common in daily life, are lacking, and existing studies rely heavily on in vitro tests to assess the risk of EDCs. Therefore, in this study, we investigated the long-term exposure effects of low-dose BP using a prostate organoid model that more closely resembles the target organ. When prostate organoids were treated with BP for a long period, hormonal imbalance was confirmed through differences in the expression of hormone receptors. In addition, reactive oxygen species (ROS) production was confirmed by DCFDA staining, and the protective effect of prostate organoids against stimulation was confirmed by increased protein levels of antioxidant factors. Through transcriptome analysis, we confirmed the occurrence of reproductive toxicity caused by BP. The long-term treatment of prostate organoids with BP causes hormonal imbalance and increased ROS exhibits reproductive toxicity and exerts a protective mechanism against BP through the expression of antioxidant factors. Our results highlight the potential of prostrate organoids as an alternative to animal experimental model and the need for further research on the effects of low EDC concentrations on male reproductive function.

Final Overall Survival and Molecular Data Associated with Clinical Outcomes in Patients Receiving Ipatasertib and Abiraterone in the Phase 3 IPATential150 Trial

BACKGROUND AND OBJECTIVE

In the phase 3 IPATential150 trial, ipatasertib addition to abiraterone significantly reduced the risk of disease progression in men with metastatic castration-resistant prostate cancer (mCRPC) with PTEN loss on immunohistochemistry (IHC), but not in the intention-to-treat (ITT) population. Here we report the final overall survival (OS) analysis and present results for prespecified and exploratory biomarker analyses.

METHODS

Patients were randomized to receive ipatasertib (400 mg once daily) or placebo. All patients received abiraterone (1000 mg once daily) and prednisone (5 mg twice daily). OS was assessed in patients with PTEN loss on IHC and the ITT population. Exploratory biomarker analyses included PTEN status via next-generation sequencing (NGS) and other key genomic alterations.

KEY FINDINGS AND LIMITATIONS

At final analysis (median follow-up 33.9 mo), ipatasertib addition did not improve OS for patients with PTEN loss in IHC (n = 521; stratified hazard ratio [sHR] 0.94, 95% confidence interval [CI] 0.76-1.17; p = 0.57) or the ITT population (n = 1101; sHR 0.91, 95% CI 0.79-1.07; not formally tested). Exploratory NGS assessments identified subgroups with genomic PTEN loss (n = 208) or PIK3CA/AKT1/PTEN alterations (n = 250), with potentially better outcomes from ipatasertib (HR 0.76, 95% CI 0.54-1.07; and HR 0.70, 95% CI 0.51-0.96, respectively). Limitations include the exploratory nature of the analysis, incomplete availability of NGS data, and potential intrapatient heterogeneity.

CONCLUSIONS AND CLINICAL IMPLICATIONS

Ipatasertib addition to abiraterone did not improve OS for men with mCRPC, regardless of PTEN status on IHC. Exploratory biomarker analyses identified additional genomic alterations of potential clinical relevance for AKT blockade in mCRPC that require further validation in prospective studies.

p53-loss induced prostatic epithelial cell plasticity and invasion is driven by a crosstalk with the tumor microenvironment

Prostate cancer is a heterogeneous disease with a slow progression and a highly variable clinical outcome. The tumor suppressor genes PTEN and TP53 are frequently mutated in prostate cancer and are predictive of early metastatic dissemination and unfavorable patient outcomes. The progression of solid tumors to metastasis is often associated with increased cell plasticity, but the complex events underlying TP53-loss-induced disease aggressiveness remain incompletely understood. Using genetically engineered mice, we show that Trp53 deficiency in Pten-null prostatic epithelial cells (PECs) does not impact early cell proliferation and neoplasia formation, nor growth arrest and senescence entry at a later time. However, Trp53-deficiency enhances invasive adenocarcinoma development and promotes metastatic cell dissemination. Importantly, our single-cell transcriptomic and chromatin accessibility analyses combined with histological examinations uncovered an epithelial cell population characterized by an induction of Jak/Stat3 signaling and displaying mesenchymal features. Moreover, we show that the transcriptomic signature of this cell population is prominent in tumors of patients with high-risk prostate cancer or metastatic disease. In addition, our in vivo and organoid-based experiments provide evidence that PEC plasticity occurs through bi-directional communication with cancer-associated fibroblasts (CAFs). Thus, our study demonstrates that p53 loss induces a protumorigenic crosstalk between PECs and CAFs, and identifies new vulnerabilities that might be targeted to limit cancer progression.

Epigenomics-guided precision oncology: Chromatin variants in prostate tumor evolution

Prostate cancer is a common malignancy that in 5%-30% leads to treatment-resistant and highly aggressive disease. Metastasis-potential and treatment-resistance is thought to rely on increased plasticity of the cancer cells-a mechanism whereby cancer cells alter their identity to adapt to changing environments or therapeutic pressures to create cellular heterogeneity. To understand the molecular basis of this plasticity, genomic studies have uncovered genetic variants to capture clonal heterogeneity of primary tumors and metastases. As cellular plasticity is largely driven by non-genetic events, complementary studies in cancer epigenomics are now being conducted to identify chromatin variants. These variants, defined as genomic loci in cancer cells that show changes in chromatin state due to the loss or gain of epigenomic marks, inclusive of histone post-translational modifications, DNA methylation and histone variants, are considered the fundamental units of epigenomic heterogeneity. In prostate cancer chromatin variants hold the promise of guiding the new era of precision oncology. In this review, we explore the role of epigenomic heterogeneity in prostate cancer, focusing on how chromatin variants contribute to tumor evolution and therapy resistance. We therefore discuss their impact on cellular plasticity and stochastic events, highlighting the value of single-cell sequencing and liquid biopsy epigenomic assays to uncover new therapeutic targets and biomarkers. Ultimately, this review aims to support a new era of precision oncology, utilizing insights from epigenomics to improve prostate cancer patient outcomes.

Early Detection of the Pathogenetic Variants of Homologous Recombination Repair Genes in Prostate Cancer: Critical Analysis and Experimental Design

It has been shown that the pathogenic variants (PVs) of the DNA Damage Response (DDR) genes, whether of a germinal or somatic nature, represent a predictive biomarker of high sensitivity to treatment with inhibitors of the enzyme poly-ADP-ribose polymerase (PARP) in patients with hormone-resistant metastatic prostate cancer (HRPCa). Moreover, the detection of PVs of the Homologous Recombination Repair (HRR) genes in PCa patients can help to define the patient's prognosis and the choice of the therapeutic procedure. Among men with metastatic PCa, the frequency of PVs in HRR genes ranges from 11% to 33%, which is a significantly higher rate compared to non-metastatic PCa, where the incidence is between 5% and 10%. Next-Generation Sequencing (NGS) results were more commonly obtained from newly acquired somatic samples compared to archived samples (prostate biopsy or prostatectomy). We developed an experimental multidisciplinary prospective study in patients with a new diagnosis of high-risk PCa at biopsy. The aim was to evaluate the presence of PVs of different HRR genes in patients with the first diagnosis of PCa in relation to a metastatic or non-metastatic stage, tumor aggressiveness, and early risk of progression. Among 43 initial tumor samples from 22 patients, 25 samples from 12 patients were selected for library preparation based on their DNA concentration and quality. After the NGS, 14 different DNA variants were prioritized. Oncogenetic and likely oncogenetic variants were found in the ATM, BRCA1, PTEN, KMT2D, and CDH1 genes. Moreover, variants of uncertain significance were found in ATM, DDR2, FANCA, FOXA1, PLCB4, PTCH1, and RB1.

Interactions between key genes and pathways in prostate cancer progression and therapy resistance

Prostate cancer is one of the most prevalent malignant tumors in men, particularly in regions with a high Human Development Index. While the long-term survival rate for localized prostate cancer is relatively high, the mortality rate remains significantly elevated once the disease progresses to advanced stages, even with various intensive treatment modalities. The primary obstacle to curing advanced prostate cancer is the absence of comprehensive treatment strategies that effectively target the highly heterogeneous tumors at both genetic and molecular levels. Prostate cancer development is a complex, multigenic, and multistep process that involves numerous gene mutations, alteration in gene expression, and changes in signaling pathways. Key genetic and pathway alterations include the amplification and/or mutation of the androgen receptor, the loss of Rb, PTEN, and p53, the activation of the WNT signaling pathway, and the amplification of the MYC oncogene. This review summarizes the mechanisms by which these genes influence the progression of prostate cancer and highlights the interactions between multiple genes and their relationship with prostate cancer. Additionally, we reviewed the current state of treatments targeting these genes and signaling pathways, providing a comprehensive overview of therapeutic approaches in the context of prostate cancer.

IL-1β in Neoplastic Disease and the Role of Its Tumor-Derived Form in the Progression and Treatment of Metastatic Prostate Cancer

Since its discovery, IL-1β has taken center stage as a key mediator of a very broad spectrum of diseases revolving around immuno-mediated and inflammatory events. Predictably, the pleiotropic nature of this cytokine in human pathology has led to the development of targeted therapeutics with multiple treatment indications in the clinic. Following the accumulated findings of IL-1β's central modulatory role in the immune system and the implication of inflammatory pathways in cancer, the use of IL-1β antagonists was first proposed and then also pursued for oncology disorders. However, this approach has consistently relied on the perceived need of interfering with IL-1β synthesized and secreted by immune cells. Herein, we discuss the importance of IL-1β derived from cancer cells which impacts primary tumors, particularly metastatic lesions, separately from and in addition to its more recognized role in immune-mediated inflammatory events. To this end, we focus on the instrumental contribution of IL-1β in the establishment and progression of advanced prostate adenocarcinoma. Special emphasis is placed on the potential role that the standard-of-care treatment strategies for prostate cancer patients have in unleashing IL-1β expression and production at metastatic sites. We conclude by reviewing the therapeutics currently used for blocking IL-1β signaling and propose a rationale for their concomitant use with standard-of-care treatments to improve the clinical outcomes of advanced prostate cancer.

Microbially produced imidazole propionate impairs prostate cancer progression through PDZK1

BACKGROUND

A close relationship exists between castration-resistant prostate cancer (CRPC) and histidine metabolism by gut microbes. However, the effects of the histidine metabolite imidazole propionate (IMP) on prostate cancer (PCa) and its underlying mechanisms are not well understood.

METHODS

We first assessed the effects of IMP on cell proliferation and migration at the cellular level. Subsequently, we investigated the mechanism of action of IMP using transcriptome sequencing, qPCR, and Western blot analysis. Finally, we validated our findings in vivo using a mouse model.

RESULTS

Histidine had no effect on PCa cell proliferation; however, IMP significantly inhibited the proliferation and migration of PC3 and DU145 cells. Mechanistic studies indicate that IMP exerts its effects by upregulating PDZK1 expression, which subsequently inhibits the phosphorylation of the PI3K-AKT pathway.

CONCLUSIONS

In conclusion, IMP significantly inhibits the progression of PCa, offering new insights into potential treatments for CRPC.

Adaptive Treatment of Metastatic Prostate Cancer Using Generative Artificial Intelligence

Despite the expanding therapeutic options available to cancer patients, therapeutic resistance, disease recurrence, and metastasis persist as hallmark challenges in the treatment of cancer. The rise to prominence of generative artificial intelligence (GenAI) in many realms of human activities is compelling the consideration of its capabilities as a potential lever to advance the development of effective cancer treatments. This article presents a hypothetical case study on the application of generative pre-trained transformers (GPTs) to the treatment of metastatic prostate cancer (mPC). The case explores the design of GPT-supported adaptive intermittent therapy for mPC. Testosterone and prostate-specific antigen (PSA) are assumed to be repeatedly monitored while treatment may involve a combination of androgen deprivation therapy (ADT), androgen receptor-signalling inhibitors (ARSI), chemotherapy, and radiotherapy. The analysis covers various questions relevant to the configuration, training, and inferencing of GPTs for the case of mPC treatment with a particular attention to risk mitigation regarding the hallucination problem and its implications to clinical integration of GenAI technologies. The case study provides elements of an actionable pathway to the realization of GenAI-assisted adaptive treatment of metastatic prostate cancer. As such, the study is expected to help facilitate the design of clinical trials of GenAI-supported cancer treatments.

Tumor-intrinsic regulators of the immune-cold microenvironment of prostate cancer

Prostate cancer (PC) is a notoriously immune-cold tumor in that it often lacks substantial infiltration by antitumor immune cells, and in advanced diseases such as neuroendocrine PC, it could be devoid of immune cells. A majority of PC patients thus have, unfortunately, been unable to benefit from recent advances in immunotherapies. What causes this immunosuppressive microenvironment around PC? In this review, we discuss various genetic and epigenetic regulators intrinsic to prostate tumor cells that could have profound effects on the tumor microenvironment, thus contributing to this immune-cold status. It will be essential to target the cancer cells themselves in order to change the tumor microenvironment to harness existing and developing immunotherapies that had great success in other tumors.

PI3K Signaling at the Crossroads of Lipid Metabolism and Cancer

The proto-oncogenic PI3K pathway is crucial for the integration of growth factor signaling and metabolic pathways to facilitate the coordination for cell growth. Since transformed cells have the ability to upregulate their anabolic pathways and selectively modulate a subset of metabolites functioning as anti- or pro-tumorigenic signal mediators, the question of how the levels of these metabolites are regulated has also become the center of attention for cancer researchers. Apart from its well-defined roles in glucose metabolism and peptide anabolism, the PI3K pathway appears to be a significant regulator of lipid metabolism and a potentiator of proto-oncogenic bioactive lipid metabolite signaling. In this review, we aim to describe the crosstalk between the PI3K pathway and bioactive lipid species of the three main lipid classes.

Loss of phosphatase and tensin homolog expression castration-sensitive prostate cancer predicts outcomes in men after prostatectomy

OBJECTIVES

This study aimed to investigate the potential for using the phosphatase and tensin homolog (PTEN) gene as a prognostic marker in post-prostatectomy patients with castration-sensitive prostate cancer (PCa).

METHODS

A total of 180 patients with castration-sensitive PCa who underwent radical prostatectomy at our institution were included in this study. PTEN expression was evaluated using immunohistochemistry, and patients were classified into two groups based on the staining intensity: PTEN-Normal and PTEN-Loss. The association between PTEN expression and biochemical recurrence was analyzed using the Cox proportional hazards model.

RESULTS

Patients in the PTEN-Loss group had a higher risk of biochemical recurrence (hazard ratio, 4.642; 95% confidence interval, 2.137-10.083; p < 0.001) and a lower recurrence-free rate compared to the PTEN-Normal group (35% vs. 75%). In addition to clinicopathological factors, such as the serum prostate-specific antigen level, Gleason score, and T stage, evaluation of PTEN expression improved the prediction of biochemical recurrence after prostatectomy (area under the curve, 0.577 vs. 0.688).

CONCLUSIONS

Low PTEN expression is a significant predictor of biochemical recurrence in patients with castration-sensitive PCa who have already undergone prostatectomy.

Understanding and overcoming resistance to immunotherapy in genitourinary cancers

The introduction of novel immunotherapies has significantly transformed the treatment landscape of genitourinary (GU) cancers, even becoming the standard of care in some settings. One such type of immunotherapy, immune checkpoint inhibitors (ICIs) like nivolumab, ipilimumab, pembrolizumab, and atezolizumab play a pivotal role by disturbing signaling pathways that limit the immune system's ability to fight tumor cells. Despite the profound impact of these treatments, not all tumors are responsive. Recent research efforts have been focused on understanding how cancer cells manage to evade the immune response and identifying the possible mechanisms behind resistance to immunotherapy. In response, ICIs are being combined with other treatments to reduce resistance and attack cancer cells through multiple cellular pathways. Additionally, novel, targeted strategies are currently being investigated to develop innovative methods of overcoming resistance and treatment failure. This article presents a comprehensive overview of the mechanisms of immunotherapy resistance in GU cancers as currently described in the literature. It explores studies that have identified genetic markers, cytokines, and proteins that may predict resistance or response to immunotherapy. Additionally, we review current efforts to overcome this resistance, which include combination ICIs and sequential therapies, novel insights into the host immune profile, and new targeted therapies. Various approaches that combine immunotherapy with chemotherapy, targeted therapy, vaccines, and radiation have been studied in an effort to more effectively overcome resistance to immunotherapy. While each of these combination therapies has shown some efficacy in clinical trials, a deeper understanding of the immune system's role underscores the potential of novel targeted therapies as a particularly promising area of current research. Currently, several targeted agents are in development, along with the identification of key immune mediators involved in immunotherapy resistance. Further research is necessary to identify predictors of response.

PTEN Loss Is Associated with Adverse Outcomes in the Setting of Salvage Radiation Therapy

BACKGROUND

Salvage radiation therapy (SRT) is a mainstay of treatment for biochemical relapse following radical prostatectomy; however, few studies have examined genomic biomarkers in this context.

OBJECTIVE

We characterized the prognostic impact of previously identified deleterious molecular phenotypes-loss of PTEN, ERG expression, and TP53 mutation-for patients undergoing SRT.

DESIGN, SETTING, AND PARTICIPANTS

We leveraged an institutional database of 320 SRT patients with available tissue and follow-up. Tissue microarrays were used for genetically validated immunohistochemistry assays.

INTERVENTION

All men underwent SRT with or without androgen deprivation therapy OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Univariable and multivariable Cox-proportional hazard models assessed the association of molecular phenotypes with biochemical recurrence-free (bRFS) and metastasis-free (MFS) survival after SRT.

RESULTS AND LIMITATIONS

Loss of PTEN (n = 123, 43%) and ERG expression (n = 118, 39%) were common in this cohort, while p53 overexpression (signifying TP53 missense mutation) was infrequent (n = 21, 7%). In univariable analyses, any loss of PTEN portended worse bRFS (hazard ratio [HR] 1.86; 95% confidence interval 1.36-2.57) and MFS (HR 1.89; 1.21-2.94), with homogeneous PTEN loss being associated with the highest risk of MFS (HR 2.47; 1.54-3.95). Similarly, p53 overexpression predicted worse bRFS (HR 1.95; 1.14-3.32) and MFS (HR 2.79; 1.50-5.19). ERG expression was associated with worse MFS only (HR 1.6; 1.03-2.48). On the multivariable analysis adjusting for known prognostic features, homogeneous PTEN loss remained predictive of adverse bRFS (HR 1.82; 1.12-2.96) and MFS (HR 2.08; 1.06-4.86). The study is limited by its retrospective and single-institution design.

CONCLUSIONS

PTEN loss by immunohistochemistry is an independent adverse prognostic factor for bRFS and MFS in prostate cancer patients treated with SRT. Future trials will determine the optimal approach to treating SRT patients with adverse molecular prognostic features.

PATIENT SUMMARY

Loss of the PTEN tumor suppressor protein is associated with worse outcomes after salvage radiotherapy, independent of other clinical or pathologic patient characteristics.

Efficacy and Safety of Combination AKT and Androgen Receptor Signaling Inhibition in Metastatic Castration-Resistant Prostate Cancer: Systematic Review and Meta-Analysis

BACKGROUND

Metastatic castration-resistant prostate cancer (mCRPC) has a poor prognosis with current treatment options including chemotherapy and androgen receptor signaling inhibitor (ARSI) medications. Poly-ADP ribose polymerase (PARP) inhibitors alone and in combination with ARSI has recently been incorporated in management for mCRPC deficient in BRCA1/2 genes. However, downregulating androgen-receptor signaling using ARSIs can upregulate the PI3K/AKT/mTOR pathway, promoting tumor cell survival. This creates a rationale for co-targeting both these pathways. This systematic review aimed to investigate AKT inhibitors and ARSI combination therapy.

METHODS

EMBASE, MEDLINE, and Scopus were searched from database inception to July 2023. Primary outcomes included objective response rate (ORR), prostate-specific antigen (PSA) response rate, adverse events (AEs), overall survival (OS), and radiographic progression-free survival (rPFS). Quality was assessed using the risk of bias tool (ROB2) and certainty of evidence with GRADE.

RESULTS

Six clinical trials with 3 Phase I, 1 Phase II, 1 Phase III were included with 771 patients and a median age ranging from 67 years to 70 years. The pooled ORR was 30% (n = 5 studies, 95% CI, 3%-84%) and PSA response rate was 43% (n = 5 studies, 95% CI, 15%-77%). The median duration of rPFS ranged from 8.2 to 19.2 months in the intervention compared with 6.4 to 16.6 months in the placebo group. A 16% reduction in radiographic progression or death was reported in patients receiving dual therapy compared with those receiving placebo. This reduction was greater by PTEN-loss status, ranging from 23% to 61%. The median OS ranged from 15.6 to 18.9 months. No significant difference was reported in survival relative to placebo. 98.8% (767/776) of patients experienced AEs of any grade, with GRADE ≥3 AEs occurring in 65.9% (512/776) of patients. The most common AE and GRADE ≥3 AEs were diarrhoea (pooled prevalence = 70%, 95% CI, 57%-81%), and hyperglycaemia (pooled prevalence = 12%, 95% CI, 6%-20%), respectively.

CONCLUSION

Combined therapy reduced the risk of rPFS, with the response higher in PTEN-loss subgroup, with a modest but not significant increase in OS. Our AE estimates showed consistency with other studies. AEs of any grade were common with the majority experiencing at least 1 AE. (PROSPERO Registration Number: CRD420202352583).

Predictors of Gleason score upgrading in patients with a biopsy diagnosis of grade group 1 prostate cancer

Background/aim

Transrectal ultrasound-guided biopsy is the most commonly used method in the diagnostic pathway of prostatic adenocarcinoma. The Gleason score of the tumor is the critical tissue-based determinant of patient management after diagnosis, and the main approach for low risk patients with grade group (GG) 1 disease is active surveillance rather than definitive interventions. However, a fair proportion of these cases are upgraded following radical prostatectomy (RP), if performed. We aimed to investigate the significance of clinicopathological parameters including phosphatase and tensin homolog (PTEN) protein in the prediction of higher final grade at RP in patients with a biopsy diagnosis of GG1 prostatic carcinoma.

Materials and methods

Thirty-three patients who underwent robotic-assisted RP for grade GG1 disease at prostate biopsy were evaluated retrospectively. Their clinical, radiological, and pathological features were explored in addition to the final histological grade in RP. Upgrade was defined as any increase in Gleason score from the initial needle biopsy to pathological analysis of the entire surgical specimen. Expression of PTEN in prostate biopsy cores was evaluated through immunohistochemistry. Multivariate logistic regression was performed to detect independent predictors of tumor upgrading from biopsy to RP.

Results

The final RP pathology revealed upgrading in 16 patients (48.5%) to GG2 disease. The statistics showed that Prostate Imaging Reporting and Data System score (≤3 vs. 4-5) of the index lesion and the number of involved cores in systematic biopsies (≤2 vs. >2) were the only independent predictors of the presence of a higher grade at RP (p < 0.05). The rate of PTEN loss for upgrading and nonupgrading patients was 25% and 5.9%, respectively, without statistical significance (p = 0.175).

Conclusion

Multiparametric magnetic resonance imaging findings and number of tumor positive needle cores are useful parameters to apply for predicting higher grade disease in the RPs of patients with a GG1 tumor diagnosis after a prostate biopsy. Immunohistochemical PTEN analysis, on the other hand, does not provide significant information in this respect.

Snake venom toxins as potential therapeutic agents in the treatment of prostate cancer

Prostate cancer is a significant global health concern and one of the leading causes of death from diseases in men. There is a growing interest in exploring new therapeutic approaches to enhance patient treatment outcomes and quality of life. Snake venom-derived compounds have emerged as promising candidates for anticancer treatment due to their potential to be selective and reduce adverse effects. In this article, we conduct a literature review on prostate cancer and discuss the investigation of snake venoms as potential alternatives in treatments to minimize toxicity and maximize efficacy. The potential of snake venom toxins in modulating key processes such as cell apoptosis, inhibition of cell migration, and angiogenesis is highlighted. This comprehensive exploration reaffirms the importance of advancing research into snake venom-based therapies to combat prostate cancer, transform treatment paradigms, and improve the well-being of affected individuals.

Comparison of Results from Two Commercially Available In-House Tissue-Based Comprehensive Genomic Profiling Solutions: Research Use Only AVENIO Tumor Tissue Comprehensive Genomic Profiling Kit and TruSight Oncology 500 Assay

Increased adoption of personalized medicine has brought comprehensive genomic profiling (CGP) to the forefront. However, differences in assay, bioinformatics, and reporting systems and lack of understanding of their complex interplay are a challenge for implementation and achieving uniformity in CGP testing. Two commercially available, tissue-based, in-house CGP assays were compared, in combination with a tertiary analysis solution in a research use only (RUO) context: the AVENIO Tumor Tissue CGP RUO Kit paired with navify Mutation Profiler (RUO) software and the TruSight Oncology 500 RUO assay paired with PierianDx Clinical Genomics Workspace software. Agreements and differences between the assays were assessed for short variants, copy number alterations, rearrangements, tumor mutational burden, and microsatellite instability, including variant categorization and clinical trial-matching (CTM) recommendations. Results showed good overall agreement for short variant, known gene fusion, and microsatellite instability detection. Important differences were obtained in tumor mutational burden scoring, copy number alteration detection, and CTM. Differences in variant and biomarker detection could be explained by bioinformatic approaches to variant calling, filtering, tiering, and normalization; differences in CTM, by underlying reported variants and conceptual differences in system parameters. Thus, distinctions between different approaches may lead to inconsistent results. Complexities in calling, filtering, and interpreting variants illustrate key considerations for implementation of any high-quality CGP in the laboratory and bringing uniformity to genomic insight results.

Cell-autonomous IL6ST activation suppresses prostate cancer development via STAT3/ARF/p53-driven senescence and confers an immune-active tumor microenvironment

BACKGROUND

Prostate cancer ranks as the second most frequently diagnosed cancer in men worldwide. Recent research highlights the crucial roles IL6ST-mediated signaling pathways play in the development and progression of various cancers, particularly through hyperactivated STAT3 signaling. However, the molecular programs mediated by IL6ST/STAT3 in prostate cancer are poorly understood.

METHODS

To investigate the role of IL6ST signaling, we constitutively activated IL6ST signaling in the prostate epithelium of a Pten-deficient prostate cancer mouse model in vivo and examined IL6ST expression in large cohorts of prostate cancer patients. We complemented these data with in-depth transcriptomic and multiplex histopathological analyses.

RESULTS

Genetic cell-autonomous activation of the IL6ST receptor in prostate epithelial cells triggers active STAT3 signaling and significantly reduces tumor growth in vivo. Mechanistically, genetic activation of IL6ST signaling mediates senescence via the STAT3/ARF/p53 axis and recruitment of cytotoxic T-cells, ultimately impeding tumor progression. In prostate cancer patients, high IL6ST mRNA expression levels correlate with better recurrence-free survival, increased senescence signals and a transition from an immune-cold to an immune-hot tumor.

CONCLUSIONS

Our findings demonstrate a context-dependent role of IL6ST/STAT3 in carcinogenesis and a tumor-suppressive function in prostate cancer development by inducing senescence and immune cell attraction. We challenge the prevailing concept of blocking IL6ST/STAT3 signaling as a functional prostate cancer treatment and instead propose cell-autonomous IL6ST activation as a novel therapeutic strategy.

Prostate Cancer: A Review of Genetics, Current Biomarkers and Personalised Treatments

BACKGROUND

Prostate cancer is the second leading cause of cancer deaths in men, second only to lung cancer. Despite this, diagnosis and prognosis methods remain limited, with effective treatments being few and far between. Traditionally, prostate cancer is initially tested for through a prostate serum antigen (PSA) test and a digital rectum examination (DRE), followed by confirmation through an invasive prostate biopsy. The DRE and biopsy are uncomfortable for the patient, so less invasive, accurate diagnostic tools are needed. Current diagnostic tools, along with genes that hold possible biomarker uses in diagnosis, prognosis and indications for personalised treatment plans, were reviewed in this article.

RECENT FINDINGS

Several genes from multiple families have been identified as possible biomarkers for disease, including those from the MYC and ETS families, as well as several tumour suppressor genes, Androgen Receptor signalling genes and DNA repair genes. There have also been advances in diagnostic tools, including MRI-targeted and liquid biopsies. Several personalised treatments have been developed over the years, including those that target metabolism-driven prostate cancer or those that target inflammation-driven cancer.

CONCLUSION

Several advances have been made in prostate cancer diagnosis and treatment, but the disease still grows year by year, leading to more and more deaths annually. This calls for even more research into this disease, allowing for better diagnosis and treatment methods and a better chance of patient survival.

DNA ploidy and PTEN as biomarkers for predicting aggressive disease in prostate cancer patients under active surveillance

BACKGROUND

Current risk stratification tools for prostate cancer patients under active surveillance (AS) may inadequately identify those needing treatment. We investigated DNA ploidy and PTEN as potential biomarkers to predict aggressive disease in AS patients.

METHODS

We assessed DNA ploidy by image cytometry and PTEN protein expression by immunohistochemistry in 3197 tumour-containing tissue blocks from 558 patients followed in AS at a Norwegian local hospital. The primary endpoint was treatment, with treatment failure (biochemical recurrence or initiation of salvage therapy) as the secondary endpoint.

RESULTS

The combined DNA ploidy and PTEN (DPP) status at diagnosis was associated with treatment-free survival in univariable- and multivariable analysis, with a HR for DPP-aberrant vs. DPP-normal tumours of 2.12 (p < 0.0001) and 1.94 (p < 0.0001), respectively. Integration of DNA ploidy and PTEN status with the Cancer of the Prostate Risk Assessment (CAPRA) score improved risk stratification (c-index difference = 0.025; p = 0.0033). Among the treated patients, those with DPP-aberrant tumours exhibited a significantly higher likelihood of treatment failure (HR 2.01; p = 0.027).

CONCLUSIONS

DNA ploidy and PTEN could serve as additional biomarkers to identify AS patients at increased risk of developing aggressive disease, enabling earlier intervention for nearly 50% of the patients that will eventually receive treatment with current protocol.

From microscopes to molecules: The evolution of prostate cancer diagnostics

In the ever-evolving landscape of oncology, the battle against prostate cancer (PCa) stands at a transformative juncture, propelled by the integration of molecular diagnostics into traditional cytopathological frameworks. This synthesis not only heralds a new epoch of precision medicine but also significantly enhances our understanding of the disease's genetic intricacies. Our comprehensive review navigates through the latest advancements in molecular biomarkers and their detection technologies, illuminating the potential these innovations hold for the clinical realm. With PCa persisting as one of the most common malignancies among men globally, the quest for early and precise diagnostic methods has never been more critical. The spotlight in this endeavor shines on the molecular diagnostics that reveal the genetic underpinnings of PCa, offering insights into its onset, progression, and resistance to conventional therapies. Among the genetic aberrations, the TMPRSS2-ERG fusion and mutations in genes such as phosphatase and tensin homolog (PTEN) and myelocytomatosis viral oncogene homolog (MYC) are identified as significant players in the disease's pathology, providing not only diagnostic markers but also potential therapeutic targets. This review underscores a multimodal diagnostic approach, merging molecular diagnostics with cytopathology, as a cornerstone in managing PCa effectively. This strategy promises a future where treatment is not only tailored to the individual's genetic makeup but also anticipates the disease's trajectory, offering hope for improved prognosis and quality of life for patients.

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.

Immunohistochemical markers as predictors of prognosis in multifocal prostate cancer

The impact of tumor focality on prostate cancer (PCa) prognosis has been addressed in several studies with conflicting results. Tumor foci from multifocal (MF) PCa can show highly heterogeneous molecular features. Our aim was to analyze the protein expression of PTEN, SPOP, SLC45A3, ETV1, ERG and the "triple hit" (ERG overexpression, PTEN plus SLC45A3 loss) in unifocal (UF) and MF PCa, to evaluate their value as prognostic markers according to focality, and the role of tumor heterogeneity in MF disease. PTEN, SPOP, SLC45A3, ETV1 and ERG immunohistochemical expression was evaluated in 185 PCa from 9 TMAs, 51 UF and 134 MF. In a subset of 69 MF cases, the dominant and secondary foci (DF and SF) were compared. Heterogeneity was considered when both tumor foci presented different expression patterns. Relationship with clinicopathological features was also analyzed. MF PCa was diagnosed in significantly younger patients when compared to UF ones (p = 0.007). ETV1 overexpression was associated with UF disease (p = 0.028). A shorter time to PSA recurrence was related to SLC45A3 wt expression in UF PCa (p = 0.052), and to SPOP expression loss (p = 0.043) or "triple hit" phenotype in MF PCa (p = 0.041). In MF cases, PTEN loss, SLC45A3 loss and "triple hit" phenotype were associated with the DF and had significant heterogeneity. In conclusion, our results indicate that UF and MF PCa have relevant and consistent molecular differences. The analysis of an immunohistochemical panel, composed by PTEN, SPOP, SLC45A3, ETV1 and ERG, could be useful to predict outcome in MF cases.

Renal cancer: signaling pathways and advances in targeted therapies

Renal cancer is a highlyheterogeneous malignancy characterized by rising global incidence and mortalityrates. The complex interplay and dysregulation of multiple signaling pathways,including von Hippel-Lindau (VHL)/hypoxia-inducible factor (HIF), phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR), Hippo-yes-associated protein (YAP), Wnt/ß-catenin, cyclic adenosine monophosphate (cAMP), and hepatocyte growth factor (HGF)/c-Met, contribute to theinitiation and progression of renal cancer. Although surgical resection is thestandard treatment for localized renal cancer, recurrence and metastasiscontinue to pose significant challenges. Advanced renal cancer is associatedwith a poor prognosis, and current therapies, such as targeted agents andimmunotherapies, have limitations. This review presents a comprehensiveoverview of the molecular mechanisms underlying aberrant signaling pathways inrenal cancer, emphasizing their intricate crosstalk and synergisticinteractions. We discuss recent advancements in targeted therapies, includingtyrosine kinase inhibitors, and immunotherapies, such as checkpoint inhibitors.Moreover, we underscore the importance of multiomics approaches and networkanalysis in elucidating the complex regulatory networks governing renal cancerpathogenesis. By integrating cutting-edge research and clinical insights, this review contributesto the development of innovative diagnostic and therapeutic strategies, whichhave the potential to improve risk stratification, precision medicine, andultimately, patient outcomes in renal cancer.

Circular RNAs: Epigenetic regulators of PTEN expression and function in cancer

Epigenetic regulation of gene expression, without altering the DNA sequence, is involved in many normal cellular growth and division events, as well as diseases such as cancer. Epigenetics is no longer limited to DNA methylation, and histone modification, but regulatory non-coding RNAs (ncRNAs) also play an important role in epigenetics. Circular RNAs (circRNAs), single-stranded RNAs without 3' and 5' ends, have recently emerged as a class of ncRNAs that regulate gene expression. CircRNAs regulate phosphatase and tensin homolog (PTEN) expression at various levels of transcription, post-transcription, translation, and post-translation under their own regulation. Given the importance of PTEN as a tumor suppressor in cancer that inhibits one of the most important cancer pathways PI3K/AKT involved in tumor cell proliferation and survival, significant studies have been conducted on the regulatory role of circRNAs in relation to PTEN. These studies will be reviewed in this paper to better understand the function of this protein in cancer and explore new therapeutic approaches.

Deep learning for automated scoring of immunohistochemically stained tumour tissue sections - Validation across tumour types based on patient outcomes

We aimed to develop deep learning (DL) models to detect protein expression in immunohistochemically (IHC) stained tissue-sections, and to compare their accuracy and performance with manually scored clinically relevant proteins in common cancer types. Five cancer patient cohorts (colon, two prostate, breast, and endometrial) were included. We developed separate DL models for scoring IHC-stained tissue-sections with nuclear, cytoplasmic, and membranous staining patterns. For training, we used images with annotations of cells with positive and negative staining from the colon cohort stained for Ki-67 and PMS2 (nuclear model), the prostate cohort 1 stained for PTEN (cytoplasmic model) and β-catenin (membranous model). The nuclear DL model was validated for MSH6 in the colon, MSH6 and PMS2 in the endometrium, Ki-67 and CyclinB1 in prostate, and oestrogen and progesterone receptors in the breast cancer cohorts. The cytoplasmic DL model was validated for PTEN and Mapre2, and the membranous DL model for CD44 and Flotillin1, all in prostate cohorts. When comparing the results of manual and DL scores in the validation sets, using manual scores as the ground truth, we observed an average correct classification rate of 91.5 % (76.9-98.5 %) for the nuclear model, 85.6 % (73.3-96.6 %) for the cytoplasmic model, and 78.4 % (75.5-84.3 %) for the membranous model. In survival analyses, manual and DL scores showed similar prognostic impact, with similar hazard ratios and p-values for all DL models. Our findings demonstrate that DL models offer a promising alternative to manual IHC scoring, providing efficiency and reproducibility across various data sources and markers.

A black phosphorus nanosheet-based RNA delivery system for prostate cancer therapy by increasing the expression level of tumor suppressor gene PTEN via CeRNA mechanism

BACKGROUND

Prostate cancer (PCa) has a high incidence in men worldwide, and almost all PCa patients progress to the androgen-independent stage which lacks effective treatment measures. PTENP1, a long non-coding RNA, has been shown to suppress tumor growth through the rescuing of PTEN expression via a competitive endogenous RNA (ceRNA) mechanism. However, PTENP1 was limited to be applied in the treatment of PCa for the reason of rapid enzymatic degradation, poor intracellular uptake, and excessively long base sequence to be synthesized. Considering the unique advantages of artificial nanomaterials in drug loading and transport, black phosphorus (BP) nanosheet was employed as a gene-drug carrier in this study.

RESULTS

The sequence of PTENP1 was adopted as a template which was randomly divided into four segments with a length of about 1000 nucleotide bases to synthesize four different RNA fragments as gene drugs, and loaded onto polyethyleneimine (PEI)-modified BP nanosheets to construct BP-PEI@RNA delivery platforms. The RNAs could be effectively delivered into PC3 cells by BP-PEI nanosheets and elevating PTEN expression by competitive binding microRNAs (miRNAs) which target PTEN mRNA, ultimately exerting anti-tumor effects.

CONCLUSIONS

Therefore, this study demonstrated that BP-PEI@RNAs is a promising gene therapeutic platform for PCa treatment.

Capivasertib in combination with enzalutamide for metastatic castration resistant prostate cancer after docetaxel and abiraterone: Results from the randomized phase II RE-AKT trial

BACKGROUND

PTEN loss and aberrations in PI3K/AKT signaling kinases associate with poorer response to abiraterone acetate (AA) in metastatic castration-resistant prostate cancer (mCRPC). In this study, we assessed antitumor activity of the AKT inhibitor capivasertib combined with enzalutamide in mCRPC with prior progression on AA and docetaxel.

METHODS

This double-blind, placebo-controlled, randomized phase 2 trial, recruited men ≥ 18 years with progressing mCRPC and performance status 0-2 from 15 UK centers. Randomized participants (1:1) received enzalutamide (160 mg orally, once daily) with capivasertib (400 mg)/ placebo orally, twice daily on an intermittent (4 days on, 3 days off) schedule. Primary endpoint was composite response rate (RR): RECIST 1.1 objective response, ≥ 50 % PSA decrease from baseline, or circulating tumor cell count conversion (from ≥ 5 at baseline to < 5 cells/7.5 mL). Subgroup analyses by PTENIHC status were pre-planned.

RESULTS

Overall, 100 participants were randomized (50:50); 95 were evaluable for primary endpoint (47:48); median follow-up was 43 months. RR were 9/47 (19.1 %) enzalutamide/capivasertib and 9/48 (18.8 %) enzalutamide/placebo (absolute difference 0.4 % 90 %CI -12.8 to 13.6, p = 0.58), with similar results in the PTENIHC loss subgroup. Irrespective of treatment, OS was significantly worse for PTENIHC loss (10.1 months [95 %CI: 4.6-13.9] vs 14.8 months [95 %CI: 10.8-18]; p = 0.02). Most common treatment-emergent grade ≥ 3 adverse events for the combination were diarrhea (13 % vs 2 %) and fatigue (10 % vs 6 %).

CONCLUSIONS

Combined capivasertib/enzalutamide was well tolerated but didn't significantly improve outcomes from abiraterone pre-treated mCRPC.

Metastatic Castration-Resistant Prostate Cancer: Advances in Treatment and Symptom Management

OPINION STATEMENT

The management of metastatic castrate-resistant prostate cancer (mCRPC) has evolved in the past decade due to substantial advances in understanding the genomic landscape and biology underpinning this form of prostate cancer. The implementation of various therapeutic agents has improved overall survival but despite the promising advances in therapeutic options, mCRPC remains incurable. The focus of treatment should be not only to improve survival but also to preserve the patient's quality of life (QoL) and ameliorate cancer-related symptoms such as pain. The choice and sequence of therapy for mCRPC patients are complex and influenced by various factors, such as side effects, disease burden, treatment history, comorbidities, patient preference and, more recently, the presence of actionable genomic alterations or biomarkers. Docetaxel is the first-line treatment for chemo-naïve patients with good performance status and those who have yet to progress on docetaxel in the castration-sensitive setting. Novel androgen agents (NHAs), such as abiraterone and enzalutamide, are effective treatment options that are utilized as second-line options. These medications can be considered upfront in frail patients or patients who are NHA naïve. Current guidelines recommend genetic testing in mCRPC for mutations in DNA repair deficiency genes to inform treatment decisions, as for example in breast cancer gene mutation testing. Other potential biomarkers being investigated include phosphatase and tensin homologues and homologous recombination repair genes. Despite a growing number of studies incorporating biomarkers in their trial designs, to date, only olaparib in the PROFOUND study and lutetium-177 in the VISION trial have improved survival. This is an unmet need, and future trials should focus on biomarker-guided treatment strategies. The advent of novel noncytotoxic agents has enhanced targeted drug delivery and improved treatment responses with favourable toxicity profiling. Trials should continue to incorporate and report health-related QoL scores and functional assessments into their trial designs.

IL-23 inhibitor enhances the effects of PTEN DNA-loaded lipid nanoparticles for metastatic CRPC therapy

Introduction: Metastatic castration-resistant prostate cancer (mCRPC) patients face challenges due to limited treatment options. About 50% of patients with mCRPC have a functional loss of phosphatase and tensin homology deleted on chromosome 10 (PTEN), leading to tumor progression, metastasis, and immune suppression. Moreover, elevated IL-23 produced by myeloid-derived suppressor cells (MDSCs) is found in CRPC patients, driving tumor progression. Therefore, a combination strategy based on PTEN restoration and IL-23 inhibition may block CRPC progression and metastasis. Methods: The antitumor effect of restoring PTEN expression combined with the IL-23 inhibitor Apilimod was studied in a mouse model of bone metastasis CRPC and mouse prostate cancer RM-1 cells. To verify the targeting ability of PTEN DNA coated with lipid nanoparticles (LNP@PTEN) in vitro and in vivo. In addition, RT-qPCR and flow cytometry were used to investigate the related mechanisms of the antitumor effect of LNP@PTEN combined with Apilimod. Results: LNPs exhibited significant tumor-targeting and tumor accumulation capabilities both in vitro and in vivo, enhancing PTEN expression and therapeutic efficacy. Additionally, the combination of LNP@PTEN with the IL-23 inhibitor Apilimod demonstrated enhanced inhibition of tumor growth, invasion, and metastasis (particularly secondary organ metastasis) compared to other groups, and extended the survival of mice to 41 days, providing a degree of bone protection. These effects may be attributed to the PTEN function restoration combined with IL-23 inhibition, which help reverse immune suppression in the tumor microenvironment by reducing MDSCs recruitment and increasing the CD8+/CD4+ T cell ratio. Discussion: In summary, these findings highlight the potential of LNPs for delivering gene therapeutic agents. And the combination of LNP@PTEN with Apilimod could achieve anti-tumor effects and improve tumor microenvironment. This combinational strategy opens new avenues for the treatment of mCRPC.

Cytotoxic and molecular differences of anticancer agents on 2D and 3D cell culture

BACKGROUND

Cancer and multidrug resistance are regarded as concerns related to poor health outcomes. It was found that the monolayer of 2D cancer cell cultures lacks many important features compared to Multicellular Tumor Spheroids (MCTS) or 3D cell cultures which instead have the ability to mimic more closely the in vivo tumor microenvironment. This study aimed to produce 3D cell cultures from different cancer cell lines and to examine the cytotoxic activity of anticancer medications on both 2D and 3D systems, as well as to detect alterations in the expression of certain genes levels.

METHOD

3D cell culture was produced using 3D microtissue molds. The cytotoxic activities of colchicine, cisplatin, doxorubicin, and paclitaxel were tested on 2D and 3D cell culture systems obtained from different cell lines (A549, H1299, MCF-7, and DU-145). IC50 values were determined by MTT assay. In addition, gene expression levels of PIK3CA, AKT1, and PTEN were evaluated by qPCR.

RESULTS

Similar cytotoxic activities were observed on both 3D and 2D cell cultures, however, higher concentrations of anticancer medications were needed for the 3D system. For instance, paclitaxel showed an IC50 of 6.234 µM and of 13.87 µM on 2D and 3D H1299 cell cultures, respectively. Gene expression of PIK3CA in H1299 cells also showed a higher fold change in 3D cell culture compared to 2D system upon treatment with doxorubicin.

CONCLUSION

When compared to 2D cell cultures, the behavior of cells in the 3D system showed to be more resistant to anticancer treatments. Due to their shape, growth pattern, hypoxic core features, interaction between cells, biomarkers synthesis, and resistance to treatment penetration, the MCTS have the advantage of better simulating the in vivo tumor conditions. As a result, it is reasonable to conclude that 3D cell cultures may be a more promising model than the traditional 2D system, offering a better understanding of the in vivo molecular changes in response to different potential treatments and multidrug resistance development.

Prostate cancer and liquid biopsies: Clinical applications and challenges

Liquid biopsy has emerged as a valuable and minimally invasive tool for real-time detection of clinically actionable abnormalities across various cancer types. Its applicability is particularly compelling in the realm of prostate cancer, where novel therapeutic agents, including those targeting DNA repair systems, are under development. Despite these advancements, challenges persist in effectively screening for prostate cancer, enhancing risk stratification, and determining optimal approaches for treating advanced disease. Consequently, there is a pressing need for improved biomarkers to aid clinicians in decision-making within these contexts. Cell-free DNA and extracellular vesicle analysis have demonstrated promise in diagnosis, prognostication, assessment of treatment responses, and identification of emerging mechanisms of resistance. Nevertheless, obstacles must be addressed before liquid biopsies can be integrated into routine clinical practice. These challenges encompass preanalytical considerations such as sample collection and storage, methods of extracellular vesicle isolation and enrichment, and the need for enhanced interpretation of generated sequencing data. This review provides a comprehensive overview of current clinical opportunities in managing prostate cancer through blood-based liquid biopsy, highlighting the progress made, and acknowledging the challenges that remain. Additionally, we discuss the next steps required for the effective implementation of liquid biopsies in guiding personalized treatment strategies for prostate cancer.