Prostate Cancer Microenvironment Research Articles

Targeting the Tumor Microenvironment in Prostate Cancer: New Frontiers in Anti-Stromal Therapies

Prostate cancer is a prevalent malignancy affecting men worldwide, contributing significantly to morbidity and mortality rates. Despite advances in treatment, many patients experience disease progression, treatment resistance, and metastasis due to the complex interplay within the tumor microenvironment (TME). The TME consists of various cellular and non-cellular components, including cancer-associated fibroblasts (CAFs), immune cells, endothelial cells, and the extracellular matrix (ECM). CAFs play a crucial role in reshaping the TME by secreting growth factors, cytokines, and remodeling enzymes that enhance tumor proliferation and survival. Immune cells contribute to immune evasion and create an immunosuppressive environment, limiting the effectiveness of conventional therapies. Angiogenesis, facilitated by endothelial cells within the TME, supports tumor vascularization and provides a constant supply of nutrients and oxygen. The ECM undergoes continuous remodeling, further facilitating cancer progression. This review explores emerging anti-stromal therapeutic strategies aimed at disrupting these critical stromal components within the TME of prostate cancer. It highlights the promise of targeting CAFs, modulating the immune landscape, inhibiting angiogenesis, and remodeling the ECM to prevent metastasis. Future research should focus on innovative combination therapies that integrate anti-stromal strategies with conventional treatments to improve patient outcomes and develop more effective interventions. Keywords: Prostate cancer, tumor microenvironment, anti-stromal therapies, cancer-associated fibroblasts, angiogenesis, immune modulation

Deciphering the Tumor Microenvironment in Prostate Cancer: A Focus on the Stromal Component

Prostate cancer progression is significantly affected by its tumor microenvironment, in which mesenchymal cells play a crucial role. Stromal cells are modified by cancer mutations, response to androgens, and lineage plasticity, and in turn, engage with epithelial tumor cells via a complex array of signaling pathways and ligand–receptor interactions, ultimately affecting tumor growth, immune interaction, and response to therapy. The metabolic rewiring and interplay in the microenvironment play an additional role in affecting the growth and progression of prostate cancer. Finally, therapeutic strategies and novel clinical trials with agents that target the stromal microenvironment or disrupt the interaction between cellular compartments are described. This review underscores cancer-associated fibroblasts as essential contributors to prostate cancer biology, emphasizing their potential as prognostic indicators and therapeutic targets.

Deciphering the effects of radiopharmaceutical therapy in the tumor microenvironment of prostate cancer: an in-silico exploration with spatial transcriptomics

Deciphering the effects of radiopharmaceutical therapy in the tumor microenvironment of prostate cancer: an in-silico exploration with spatial transcriptomics

Tumor Microenvironment and Dermatological Conditions in Prostate Cancer

Tumor initiation, progression, and invasion are closely related to the tumor microenvironment. Inflammation can modulate the activity of the cells in the TME and contribute to all stages of tumor development. The etiopathogenesis of cutaneous manifestations associated with prostate cancer is unclear. The cutaneous phenotype associated with prostate cancer could be supported by intratumoral heterogeneity, the remodeling of interactions in the tumor microenvironment, and the dynamics of the epithelial–mesenchymal transition. Among the urinary system cancers, prostate cancer presents few cutaneous signs and symptoms, most being diagnosed in the advanced stages of the disease. In this review, we analyze the cutaneous events associated with prostate cancer, represented by direct or indirect manifestations of the primary malignancy and the skin toxicities caused by oncological medications.

The Immune Microenvironment in Prostate Cancer: A Comprehensive Review.

Prostate cancer (PCa) is a malignancy with significant immunosuppressive properties and limited immune activation. This immunosuppression is linked to reduced cytotoxic T-cell activity, impaired antigen presentation, and elevated levels of immunosuppressive cytokines and immune checkpoint molecules. Studies demonstrate that cytotoxic CD8+ T cell infiltration correlates with improved survival, while increased regulatory T cells (Tregs) and tumor-associated macrophages (TAMs) are associated with worse outcomes and therapeutic resistance. Th1 cells are beneficial, whereas Th17 cells, producing interleukin-17 (IL-17), contribute to tumor progression. Tumor-associated neutrophils (TANs) and immune checkpoint molecules like PD-1/PD-L1 and TIM-3 are also linked to advanced stages of PCa. Chemotherapy holds promise in converting the "cold" tumor microenvironment (TME) to a "hot" one by depleting immunosuppressive cells and enhancing tumor immunogenicity. This comprehensive review examines the immune microenvironment in PCa, focusing on the intricate interactions between immune and tumor cells in the TME. It highlights how TAMs, Tregs, cytotoxic T cells, and other immune cell types contribute to tumor progression or suppression and how PCa's low immunogenicity complicates immunotherapy. The infiltration of cytotoxic CD8+ T cells and Th1 cells correlates with better outcomes, while elevated Tregs and TAMs promote tumor growth, metastasis, and resistance. TANs and NK cells exhibit dual roles, with higher NK cell levels linked to better prognoses. Immune checkpoint molecules like PD-1, PD-L1, and TIM-3 are associated with advanced disease. Chemotherapy can improve tumor immunogenicity by depleting Tregs and MDSCs, offering therapeutic promise.

Steroid Hormones Modulation of the Tumor Microenvironment in Prostate Cancer

Steroid Hormones Modulation of the Tumor Microenvironment in Prostate Cancer

Genetically modified extracellular vesicles loaded with activated gasdermin D potentially inhibit prostate-specific membrane antigen-positive prostate carcinoma growth and enhance immunotherapy

Prostate cancer (PCa) is associated with poor immunogenicity and lymphocytic infiltration, and immunotherapy effective against PCa remains unavailable. Pyroptosis, a novel immunotherapeutic modality for cancer, promotes systemic immune responses leading to immunogenic cell death in solid tumors. This paper describes the preparation and analysis of PSMAscFv-EVN-GSDMD; this genetically engineered recombinant extracellular vesicle (EV) expresses a single-chain variable antibody fragment (scFv) with high affinity for prostate-specific membrane antigen (PSMA) on their surfaces and is loaded with the N-terminal domain of gasdermin D (GSDMD). Both in vitro and in vivo, PSMAscFv-EVN-GSDMD effectively targeted PSMA-positive PCa cells and induced pyroptosis through the carrier properties of EVs and the specificity of PSMAscFv. In the 22RV1 and PSMA-transfected RM-1-inoculated PCa mouse models, PSMAscFv-EVN-GSDMD efficiently inhibited tumor growth and promoted tumor immune responses. In conclusion, PSMAscFv-EVN-GSDMD can convert the immunosuppressive “cold” tumor microenvironment of PCa into an immunogenic “hot” tumor microenvironment.

Exploring the interaction between immune cells in the prostate cancer microenvironment combining weighted correlation gene network analysis and single-cell sequencing: An integrated bioinformatics analysis.

The rise of treatment resistance and variability across malignant profiles has made precision oncology an imperative in today's medical landscape. Prostate cancer is a prevalent form of cancer in males, characterized by significant diversity in both genomic and clinical characteristics. The tumor microenvironment consists of stroma, tumor cells, and various immune cells. The stromal components and tumor cells engage in mutual communication and facilitate the development of a low-oxygen and pro-cancer milieu by producing cytokines and activating pro-inflammatory signaling pathways. In order to discover new genes associated with tumor cells that interact and facilitate a hypoxic environment in prostate cancer, we conducted a cutting-edge bioinformatics investigation. This included analyzing high-throughput genomic datasets obtained from the cancer genome atlas (TCGA). A combination of weighted gene co-expression network analysis and single-cell sequencing has identified nine dysregulated immune hub genes (AMACR, KCNN3, MME, EGFR, FLT1, GDF15, KDR, IGF1, and KRT7) that are believed to have significant involvement in the biological pathways involved with the advancement of prostate cancer enviriment. In the prostate cancer environment, we observed the overexpression of GDF15 and KRT7 genes, as well as the downregulation of other genes. Additionally, the cBioPortal platform was used to investigate the frequency of alterations in the genes and their effects on the survival of the patients. The Kaplan-Meier survival analysis indicated that the changes in the candidate genes were associated with a reduction in the overall survival of the patients. In summary, the findings indicate that studying the genes and their genomic changes may be used to develop precise treatments for prostate cancer. This approach involves early detection and targeted therapy.

The biological function of extracellular vesicles in prostate cancer and their clinical application as diagnostic and prognostic biomarkers.

Prostate cancer (PCa) is one of the most commonly diagnosed malignancies and main causes of cancer-related deaths worldwide. It is characterized by high heterogeneity, ranging from slow-growing tumor to metastatic disease. Since both therapy selection and outcome strongly rely on appropriate patient stratification, it is crucial to differentiate benign from more aggressive conditions using new and improved diagnostic and prognostic biomarkers. Extracellular vesicles (EVs) are membrane-coated particles carrying a specific biological cargo composed of nucleic acids, proteins, and metabolites. Here, we provide an overview of the role of EVs in PCa, focusing on both their biological function and clinical value. Specifically, we summarize the oncogenic role of EVs in mediating the interactions with PCa microenvironment as well as the horizontal transfer of metastatic traits and drug resistance between PCa cells. Furthermore, we discuss the potential usage of EVs as innovative tools for PCa diagnosis and prognosis.

Abstract C118: Modulation of Prostate Cancer Microenvironment and Immune Responses by SPDEF

Abstract Introduction: The prostate cancer (PCa) microenvironment plays a pivotal role in modulating immune responses, potentially impacting disease progression and treatment outcomes. SPDEF, a transcription factor, has been implicated in PCa progression, yet its influence on the tumor immune microenvironment remains incompletely understood. Methods: To comprehensively evaluate the impact of SPDEF-mediated changes in the PCa microenvironment on immune cells, we employed multiple experimental approaches. Firstly, utilizing the ProcartaPlex Human Cytokine & Chemokine Panel 1 16plex assay, we analyzed cytokine and chemokine alterations in cell culture supernatants from various PCa cell line models—PC3-VC, PC3-SPDEF, RC77/T-VC, RC77/T-SPDEF, LNCaP-VC, and LNCaP-shSPDEF. Subsequently, human primary T cells were exposed to PCa cell-derived conditioned media to assess their proliferation and activation status, using IncuCyte cell imaging and flow cytometry, respectively. Results: Our ProcartaPlex assay validated transcriptomic observations from RNA-seq experiment, confirming elevated cytokine/chemokine levels in SPDEF-overexpressing models and decreased levels in SPDEF-suppressed conditions. Notably, T cell proliferation assays demonstrated increased proliferation in response to SPDEF-overexpressing PCa conditional media and diminished proliferation in SPDEF-suppressed conditions. Moreover, SPDEF downregulation led to decreased proliferation in both CD4+ and CD8+ T cells. Assessing CD8+ T cell activation markers revealed varying impacts on IFN-γ expression, showing reduced levels in LNCaP-shSPDEF but inconclusive effects in PC3-SPDEF overexpression models. Conclusions: These findings highlight the complex interplay between SPDEF alterations in the PCa microenvironment and immune cell behavior, particularly T cell proliferation and activation. The observed effects underscore the complexity of SPDEF-mediated alterations on immune responses within the tumor milieu. Further investigations into the divergent effects of SPDEF on T cell dynamics are warranted to elucidate the precise mechanisms governing these interactions, potentially offering insights into novel therapeutic targets for PCa. Citation Format: Mousa K. Vatanmakanian, Maria Sanchez-Pino, Guanyi K. Zhang, Sweaty Koul, Ramesh T. Puttalingaiah, Mathew Dean, Dorota K. Wyczechowska, Augusto Ochoa, Hari K Koul. Modulation of Prostate Cancer Microenvironment and Immune Responses by SPDEF [abstract]. In: Proceedings of the 17th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2024 Sep 21-24; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2024;33(9 Suppl):Abstract nr C118.

NDR1 mediates PD-L1 deubiquitination to promote prostate cancer immune escape via USP10

Prostate cancer (PCa) is one of the most common male genitourinary system malignancies. Despite the significant benefits of anti-PD-L1 immune checkpoint inhibitor therapy in other cancers, the reasons for its poor therapeutic efficacy in prostate cancer (PCa) remain unclear.NDR1 plays an important role in innate immunity, but its role in tumor immunity and immunotherapy has not been investigated. The role of NDR1 in the immune microenvironment of PCa and the related mechanisms are unknown. Here, we found a positive correlation between NDR1 and PD-L1 expression in PCa. NDR1 significantly inhibits CD8 + T cell infiltration and function, thereby promoting immune escape in prostate cancer.More importantly, NDR1 inhibition significantly enhanced CD8 + T cell activation, which enhanced the therapeutic effect of anti-PD-L1. Mechanistic studies revealed that NDR1 inhibits ubiquitination-mediated PD-L1 degradation via the deubiquitinase USP10, upregulates PD-L1, and promotes PCa immune escape. Thus, our study suggests a unique PD-L1 regulatory mechanism underlying PCa immunotherapy failure. The significance of NDR1 in PCa immune escape and its mechanism of action were clarified, and combined NDR1/PD-L1 inhibition was suggested as an approach to boost PCa immunotherapy effectiveness.Graphical

Ferroptosis-related gene signature predicts prognosis and immune microenvironment in prostate cancer.

Ferroptosis, an iron-dependent form of programmed cell death, significantly impacts cancer, yet its link to prostate cancer (PCa) prognosis remains underexplored. This study aims to develop and validate a ferroptosis-related gene signature to predict PCa prognosis and immune microenvironment differences, potentially identifying therapeutic targets. RNA-sequencing data of 478 PCa patients and corresponding clinical data were downloaded from The Cancer Genome Atlas (TCGA) database. We investigated the disease-free survival (DFS) rates of the high- and low-risk groups using the Kaplan-Meier method. Functional differences between the high- and low-risk groups were investigated by a gene set enrichment analysis (GSEA), and Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. The link between ferroptosis risk score and immune status was examined using CIBERSORT. The expression levels of core prognostic genes in benign prostatic hyperplasia (BPH) and PCa were verified using quantitative real-time polymerase chain reaction (qRT-PCR), Western blot, and immunohistochemistry (IHC). A novel ferroptosis-related prognostic gene signature was established and tested in the Gene Expression Omnibus (GEO) database based on univariate and multivariate Cox regression analyses. Patients with PCa were classified into high- and low-risk groups based on this ferroptosis signature. Patients in the high-risk group had worse outcomes than those in the low-risk group. The predictive accuracy of the model was demonstrated by a receiver operating characteristic (ROC) analysis. An additional enrichment analysis of TCGA cohort revealed the immune-related pathways were significantly upregulated in the high-risk group, with areas under the curve (AUCs) of 0.85 at 1 year, 0.82 at 3 years, and 0.76 at 5 years. In the GEO cohort, the AUCs reached 0.69 at 1 year, 0.74 at 3 years, and 0.75 at 5 years. An additional enrichment analysis indicated a significant upregulation of cytokine-related pathways, immune receptor activity, and other immune-related pathways in the high-risk group. Furthermore, the analysis revealed that the proportions of mast cells and plasma cells were significantly lower in the high-risk group compared to the low-risk group of PCa patients. Conversely, the proportion of regulatory T cells (Tregs) was significantly higher in the high-risk group than in the low-risk group. According to the qRT-PCR, Western blot, and IHC results, DRD4, SRC, AKR1C2, and AIFM2 expression was significantly higher in PCa than BPH. We also showed that the ferrostatin 1-treated LNCaP cells had higher expression levels of DRD4, SRC, and AKR1C2. A prognostic signature of eight ferroptosis-related genes (FRGs) that may accurately predict PCa patient outcomes was constructed and validated. FRGs may contribute to anti-tumor immunity and serve as therapeutic targets in PCa.

Machine learning-based cell death marker for predicting prognosis and identifying tumor immune microenvironment in prostate cancer

BackgroundProstate cancer (PCa) incidence and mortality rates are rising, necessitating precise prognostic tools to guide personalized treatment. Dysregulation of programmed cell death pathways in tumor suppression and cancer development has garnered increasing attention, providing a new research direction for identifying biomarkers and potential therapeutic targets. MethodsIntegrating multiple database resources, we constructed and optimized a prognostic signature based on the expression of programmed cell death-related genes (PCDRG) using ten machine learning algorithms. Model performance and prognostic effects were further evaluated. We analyzed the relationships between signature and clinicopathological features, somatic mutations, drug sensitivity, and the tumor immune microenvironment, and constructed a nomogram. The expression level of PCDRGs were evaluated and compared. ResultsOf 1560 PCDRGs, 149 were differentially expressed in PCa, with 34 associated with biochemical recurrence. The PCDRG-derived index (PCDI), constructed using the random forest algorithm, exhibited optimal prognostic performance, successfully stratifying PCa patients into two groups with significant prognostic differences. Patients with high PCDI scores exhibited poorer survival and lower immunotherapy benefit. PCDI was closely associated with the infiltration of specific immune cells, particularly positive correlations with macrophages and T helper cells, and negative correlations with neutrophils, suggesting that PCDI may influence the tumor immune microenvironment, thereby affecting patient prognosis and treatment response. PCDI was associated with age, pathological stage, somatic mutations, and drug sensitivity. The PCDI-based nomogram demonstrated excellent performance in predicting biochemical recurrence in PCa patients. Finally, the differential expression of these PCDRGs was verified based on cell lines and PCa patient expression profile data. ConclusionThis study developed an effective prognostic indicator for prostate cancer, PCDI, using machine learning approaches. PCDI reflects the link between aberrant programmed cell death pathways and disease progression and treatment response.

Exosomes That Have Different Cellular Origins Followed by the Impact They Have on Prostate Tumor Development in the Tumor Microenvironment.

Prostate cancer (PCa) is the most common urinary tumor with the highest incidence rate and the second among the leading causes of death worldwide for adult males. In the worldwide cancer incidence rate, PCa is on the increase. The cancerous cells in the prostate and cells in the microenvironment surrounding the tumor communicate through signal transduction, which is crucial for the development and spread of PCa. Exosomes are nanoscale vesicles released into body fluids by various cells that can aid intercellular communication by releasing nucleic acids and proteins. Exosomes published by different types of cells in the tumor microenvironment can have varying impacts on the proliferation and growth of tumor cells via various signaling pathways, modes of action, and secreted cytokines. The main purpose of this review is to describe the effects of different cell-derived exosomes in the tumor microenvironment of PCa on the progression of tumor cells, as well as to summarize and discuss the prospects for the application of exosomes in the treatment and diagnosis of PCa.

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.

The reactive stroma response regulates the immune landscape in prostate cancer

Prostate cancer remains the most commonly diagnosed and the second leading cause of cancer-related deaths in men in the United States. The neoplastic transformation of prostate epithelia, concomitant with modulations in the stromal compartment, known as reactive stromal response, is critical for the growth, development, and progression of prostate cancer. Reactive stroma typifies an emergent response to disrupted tissue homeostasis commonly observed in wound repair and pathological conditions such as cancer. Despite the significance of reactive stroma in prostate cancer pathobiology, our understanding of the ontogeny, phenotypic and functional heterogeneity, and reactive stromal regulation of the immune microenvironment in prostate cancer remains limited. Traditionally characterized to have an immunologically "cold" tumor microenvironment, prostate cancer presents significant challenges for advancing immunotherapy compared to other solid tumors. This review explores the detrimental role of reactive stroma in prostate cancer, particularly its immunomodulatory function. Understanding the molecular characteristics and dynamic transcriptional program of the reactive stromal populations in tandem with tumor progression could offer insights into enhancing immunotherapy efficacy against prostate cancer.

Notch signaling suppresses neuroendocrine differentiation and alters the immune microenvironment in advanced prostate cancer.

Notch signaling can have either an oncogenic or tumor suppressive function in cancer depending on the cancer type and cellular context. While Notch can be oncogenic in early prostate cancer, we identified significant downregulation of the Notch pathway during prostate cancer progression from adenocarcinoma to neuroendocrine prostate cancer where it functions as a tumor suppressor. Activation of Notch in neuroendocrine and Rb1/Trp53-deficient prostate cancer models led to phenotypic conversion towards a more indolent non-neuroendocrine state with glandular features and expression of luminal lineage markers. This was accompanied by up-regulation of MHC and type I interferon and immune cell infiltration. Overall, these data support Notch signaling as a suppressor of neuroendocrine differentiation in advanced prostate cancer and provides insights into how Notch signaling influences lineage plasticity and the tumor microenvironment.

Binding of interleukin-1 receptor antagonist to cholinergic receptor muscarinic 4 promotes immunosuppression and neuroendocrine differentiation in prostate cancer

The tumor microenvironment (TME) of prostate cancer (PCa) is characterized by high levels of immunosuppressive molecules, including cytokines and chemokines. This creates a hostile immune landscape that impedes effective immune responses. The interleukin-1 (IL-1) receptor antagonist (IL1RN), a key anti-inflammatory molecule, plays a significant role in suppressing IL-1-related immune and inflammatory responses. Our research investigates the oncogenic role of IL1RN in PCa, particularly its interactions with muscarinic acetylcholine receptor 4 (CHRM4), and its involvement in driving immunosuppressive pathways and M2-like macrophage polarization within the PCa TME. We demonstrate that following androgen deprivation therapy (ADT), the IL1RN-CHRM4 interaction in PCa activates the MAPK/AKT signaling pathway. This activation upregulates the transcription factors E2F1 and MYCN, stimulating IL1RN production and creating a positive feedback loop that increases CHRM4 abundance in both PCa cells and M2-like macrophages. This ADT-driven IL1RN/CHRM4 axis significantly enhances immune checkpoint markers associated with neuroendocrine differentiation and treatment-resistant outcomes. Higher serum IL1RN levels are associated with increased disease aggressiveness and M2-like macrophage markers in advanced PCa patients. Additionally, elevated IL1RN levels correlate with better clinical outcomes following immunotherapy. Clinical correlations between IL1RN and CHRM4 expression in advanced PCa patients and neuroendocrine PCa organoid models highlight their potential as therapeutic targets. Our data suggest that targeting the IL1RN/CHRM4 signaling could be a promising strategy for managing PCa progression and enhancing treatment responses.

Identification of anoikis-related gene signatures and construction of the prognosis model in prostate cancer.

One of the primary reasons for tumor invasion and metastasis is anoikis resistance. Biochemical recurrence (BCR) of prostate cancer (PCa) serves as a harbinger of its distant metastasis. However, the role of anoikis in PCa biochemical recurrence has not been fully elucidated. Differential expression analysis was used to identify anoikis-related genes based on the TCGA and GeneCards databases. Prognostic models were constructed utilizing LASSO regression, univariate and multivariate Cox regression analyses. Moreover, Gene Expression Omnibus datasets (GSE70770 and GSE46602) were applied as validation cohorts. Gene Ontology, KEGG and GSVA were utilized to explore biological pathways and molecular mechanisms. Further, immune profiles were assessed using CIBERSORT, ssGSEA, and TIDE, while anti-cancer drugs sensitivity was analyzed by GDSC database. In addition, gene expressions in the model were examined using online databases (Human Protein Atlas and Tumor Immune Single-Cell Hub). 113 differentially expressed anoikis-related genes were found. Four genes (EEF1A2, RET, FOSL1, PCA3) were selected for constructing a prognostic model. Using the findings from the Cox regression analysis, we grouped patients into groups of high and low risk. The high-risk group exhibited a poorer prognosis, with a maximum AUC of 0.897. Moreover, larger percentage of immune infiltration of memory B cells, CD8 Tcells, neutrophils, and M1 macrophages were observed in the high-risk group than those in the low-risk group, whereas the percentage of activated mast cells and dendritic cells in the high-risk group were lower. An increased TIDE score was founded in the high-risk group, suggesting reduced effectiveness of ICI therapy. Additionally, the IC50 results for chemotherapy drugs indicated that the low-risk group was more sensitive to most of the drugs. Finally, the genes EEF1A2, RET, and FOSL1 were expressed in PCa cases based on HPA website. The TISCH database suggested that these four ARGs might contribute to the tumor microenvironment of PCa. We created a risk model utilizing four ARGs that effectively predicts the risk of BCR in PCa patients. This study lays the groundwork for risk stratification and predicting survival outcomes in PCa patients with BCR.

Improving cancer immunotherapy in prostate cancer by modulating T cell function through targeting the galectin-1.

Our study aimed to elucidate the role of Galectin-1 (Gal-1) role in the immunosuppressive tumor microenvironment (TME) of prostate cancer (PCa). Our previous findings demonstrated a correlation between elevated Gal-1 expression and advanced PCa stages. In this study, we also observed that Gal-1 is expressed around the tumor stroma and its expression level is associated with PCa progression. We identified that Gal-1 could be secreted by PCa cells, and secreted Gal-1 has the potential to induce T cell apoptosis. Gal-1 knockdown or inhibition of Gal-1 function by LLS30 suppresses T cell apoptosis resulting in increased intratumoral T cell infiltration. Importantly, LLS30 treatment significantly improved the antitumor efficacy of anti-PD-1 in vivo. Mechanistically, LLS30 binds to the carbohydrate recognition domain (CRD) of Gal-1, disrupting its binding to CD45 leading to the suppression of T cell apoptosis. In addition, RNA-seq analysis revealed a novel mechanism of action for LLS30, linking its tumor-intrinsic oncogenic effects to anti-tumor immunity. These findings suggested that tumor-derived Gal-1 contributes to the immunosuppressive TME in PCa by inducing apoptosis in effector T cells. Targeting Gal-1 with LLS30 may offer a strategy to enhance anti-tumor immunity and improve immunotherapy.