The androgen receptor (AR) is the primary therapeutic target in prostate cancer. While androgen deprivation therapy (ADT) and androgen receptor signaling inhibitors (ARSi) are effective, the disease eventually progresses to fatal castration-resistant prostate cancer (CRPC). That said, little is known about the mechanisms in residual disease that initiates tumor relapse upon ADT/ARSi. Here, we discover a crucial role for TRIM24 in supporting the survival of residual cell clusters primed for tumor relapse in vivo. Consequently, reducing TRIM24 with bifunctional degraders (dTRIM24) significantly delays or even prevents the emergence of CRPC in the context of AR reactivation and lineage plasticity in vivo. dTRIM24 not only inhibits further AR signaling under ADT/ARSi but also counteracts adaptive pathways engaged by AR inhibition itself, such as STAT3 activation and EMT. Our findings underscore the potential of TRIM24 as an effective and druggable target for preventing prostate cancer progression under AR inhibition. Daniela Bossi, Arianna Vallerga, Giuseppe Salfi, Nicolo Formaggio, Zhang Jichang, Tiziano Bernasocchi, Andrea Rinaldi, Lukas Bubendorf, Simone Mosole, Eva Corey, Marco Bolis, Matteo Pecoraro, Roger Geiger, Wouter Karthaus, Ricardo Pereira Mestre, Jinhua Wang, Jean-Philippe Paul. Theurillat. TRIM24 degradation counteracts adaptation to androgen receptor inhibition in prostate cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Innovations in Prostate Cancer Research and Treatment; 2026 Jan 20-22; Philadelphia PA. Philadelphia (PA): AACR; Cancer Res 2026;86(2_Suppl):Abstract nr B076.

Senescent cells drive ageing and age-related pathologies, including cancer. Consequently, senolytics, drugs that selectively kill senescent cells, have broad therapeutic appeal. Here we report a senolytic screen of a library of 10,480 electrophilic compounds. Among 38 identified hits, we found a subset of chloroacetamides with broad senolytic activity. Activity-based protein profiling, coupled with functional assays, identified the glutathione peroxidase GPX4 as a target. We show that senescent cells are primed for ferroptosis, displaying high levels of oxidative stress and intracellular Fe2+, but also upregulate GPX4, which prevents the accumulation of oxidized lipids. Treatment with senolytic chloroacetamides or GPX4 inhibitors selectively kills senescent cells by ferroptosis. The combination of anticancer therapies with GPX4 inhibitors eliminated senescent tumour cells in models of melanoma, prostate and ovarian cancer. Our results show that senescent cells rely on GPX4 to prevent ferroptosis and that GPX4 inhibitors kill senescent cells.

The androgen receptor (AR) is the primary therapeutic target in prostate cancer. While androgen deprivation therapy (ADT) and androgen receptor signaling inhibitors (ARSi) are effective, the disease eventually progresses to fatal castration-resistant prostate cancer (CRPC). That said, little is known about the mechanisms in residual disease that initiates tumor relapse upon ADT/ARSi. Here, we discover a crucial role for TRIM24 in supporting the survival of residual cell clusters primed for tumor relapse in vivo. Consequently, reducing TRIM24 with bifunctional degraders (dTRIM24) significantly delays or even prevents the emergence of CRPC in the context of AR reactivation and lineage plasticity. dTRIM24 not only inhibits AR signaling but also counteracts adaptive pathways engaged by AR inhibition itself, such as STAT3 activation and EMT. Our findings underscore the potential of TRIM24 as an effective and druggable target for preventing prostate cancer progression under AR inhibition. Significance Despite advances in targeting AR signaling in prostate cancer, tumor relapse remains a major concern. Here, we provide evidence that more durable responses can be achieved by pharmacologically degrading TRIM24. At the molecular level, TRIM24 degradation inhibits both AR signaling and adaptive pathways that enable tumor relapse. ### Competing Interest Statement J.P.T. and D.B. filed an Italian patent application (No. 10202400000504) relating to the manuscript's content, titled "Pharmacological degradation of TRIM24 inhibits castration-resistant prostate cancer growth and synergizes with hormonal therapy to prevent disease progression". J.P.T. has received funding for the venue of scientific conferences from Astellas, AstraZeneca, Pfizer, Janssen, Bayer, and Orion Pharma, and has received honoraria for consulting or advisory roles from Astellas. The other authors report no other disclosures related to the content of the manuscript.

Recent studies demonstrate that the gut mycobiota plays a key role in several tumors. However, the contribution of commensal fungi to prostate cancer initiation and progression remains understudied. Here we find that Nakaseomyces glabratus is enriched in fecal, blood and tumor samples of patients with castration-resistant prostate cancer, correlating with patients’ poor overall survival. Oral administration of N. glabratus to castrated mice accelerated cancer progression by promoting infiltration and activation of polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs). Mechanistically, androgen deprivation therapy increases intestinal permeability, resulting in the leakage of N. glabratus from the gut to the tumor site, activating PMN-MDSCs via the Dectin-2 receptor. Treatment of mice with a negatively charged intestinal hydrogel blocks N. glabratus translocation to tumor, reducing PMN-MDSCs’ intratumoral infiltration and activation. Taken together, these findings reveal that the gut-to-tumor translocation of N. glabratus contributes to endocrine resistance in prostate cancer by enhancing the immunosuppressive microenvironment of these tumors. Lai et al. show that Nakaseomyces glabratus is enriched in fecal and tumor samples of patients with castration-resistant prostate cancer and that administration of the fungus accelerates cancer progression in prostate cancer-bearing castrated mice.

Regulatory factor X 7 (RFX7) nonsense mutations have been found in different human B cell malignancies. We therefore set out to study the role of RFX7 in B cell activation and lymphomagenesis. Here we show that RFX7 truncations cause loss-of-function and dominant-negative effects. Moreover, low RFX7 mRNA levels correlate with worse diffuse large B cell lymphoma prognosis. Accordingly, Rfx7 deletion in B cells accelerates pathogenesis in mouse Bcl6- and p53-loss-driven B cell lymphoma models. Rfx7-deficient B cells exhibit increased Myc activity and enhanced germinal center B cell and plasmablast responses. These alterations are reverted by Myc haploinsufficiency, which provides partial protection from nonsymptomatic p53-/-Rfx7-/- B cell lymphoma, but does not prevent detrimental Myc deregulation in aggressive disease. Deletion of Aicda, which favors genomic alterations in activated B cells, limits lymphoma development in the p53-/-Rfx7-/- double-hit mouse model. These results indicate that Rfx7 represses B cell activation, Myc activity, and Myc- and activation-induced cytidine deaminase (AID)-dependent pro-lymphomagenic processes.

Prostate-specific membrane antigen (PSMA), a type II transmembrane glycoprotein belonging to the folate receptor family, is highly expressed in metastatic castration-resistant prostate cancer (mCRPC), and increases following androgen deprivation therapy (ADT). PSMA is a validated diagnostic and therapeutic target for radioligands and antibody-drug conjugates (ADCs). TD001 is a novel ADC composed of a deimmunized anti-PSMA IgG1 monoclonal antibody (HuJ591) conjugated to a highly stable protease-cleavable proprietary linker and the potent Topo I inhibitor exatecan payload. The LD038 linker-payload leverages exatecan’s ability to stabilize Topo I-DNA complexes and induce DNA damage and cell death. We tested TD001 in 2D and 3D cell cultures and in vivo in human CRPC xenograft models with different levels of PSMA expression. We evaluated cell internalization, payload release, and drug activity by flow cytometry, immunohistochemistry, and immunofluorescence microscopy. Free payload levels were measured 24 h post treatment in plasma and tumors by LC-MS/MS. TD001 showed efficient binding and rapid internalization within 1-3 h followed by lysosomal localization and payload release in PSMA-expressing cells. Due to the quick and effective payload release, TD001 exhibited selective and potent activity with the induction of Topo I-mediated DNA damage (gamma-H2AX) and apoptosis (cleaved caspase 3). TD001 had no effect on PSMA-negative cells. This was supported by 3D cell culture models, which demonstrated rapid diffusion into the extracellular matrix, and rapid internalization of TD001 into PSMA-expressing tumor cells. TD001 was evaluated in vivo in three CRPC xenograft models with different PSMA expression patterns: the high/homogenous (∼104 ligands/cell) PSMA-expressing LNCaP-abl cell line-derived xenograft (CDX) castrated mouse model, the intermediate/heterogeneous (∼102-104 ligands/cell) PSMA-expressing 22Rv1 CDX castrated mouse model, and the AR-positive, high/homogenous (∼105 ligands/cell)-PSMA-expressing patient-derived xenograft (PDX) C5 mouse model. The LD038 linker-payload in TD001 resulted in high free payload release within tumor tissue, triggering DNA damage, cell death, and growth arrest. Notably, tumor uptake and a very high tumor/plasma ratio (70-100 fold) of exatecan were similar 24 h after IV administration in all three in vivo models despite substantial differences in PSMA expression and heterogeneity. These findings highlight the ability of TD001 to deliver effectively and selectively the payload exatecan to PSMA-positive prostate tumors, resulting in potent antitumor activity in different CRPC models, including those with intermediate and heterogenous PSMA expression. Daniela Impellizzieri, Elisa Storelli, Atik Balla, Simone Mosole, Cristina Dongilli, Federico Jauk, Roberta Frapolli, Lavinia Morosi, Maurizio D'Incalci, Jemila Houacine, Morris Rosenberg, Bérangère Deleglise, Esteban Cvitkovic, Carlo V. Catapano. Improved tumor penetration and cytotoxic payload release with TD001, a novel PSMA-targeting ADC with optimized linker-payload composition, in PSMA-expressing CRPC CDX castrated mouse models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 314.

Patients with metastatic castration-resistant prostate cancer (mCRPC) who progress on androgen deprivation therapy (ADT) have limited therapeutic options. Prostate-specific membrane antigen (PSMA) is a type II transmembrane glycoprotein highly expressed in mCRPC and is a validated target for precision medicine approaches. TD001 is a novel antibody-drug conjugate (ADC) composed of a deimmunized anti-PSMA IgG1 monoclonal antibody (HuJ591) conjugated to a highly stable protease-cleavable topoisomerase I inhibitor (exatecan) proprietary linker-payload (LD038) with a drug-to-antibody ratio (DAR) of 8. TD001 was evaluated in vivo in human cell line-derived xenograft (CDX) models with high PSMA expression (LNCaP-abl; ∼104 ligands/cell) or intermediate/heterogeneous PSMA expression (22Rv1; ∼102-104 ligands/cell) in castrated NRG mice, and in the high PSMA-expressing (∼105 ligands/cell) patient-derived xenograft (PDX) model C5 in non-castrated NRG mice. Of note, PSMA expression increased upon castration in both CDX models, mimicking the clinical condition of the target patient population. After single IV administration across a wide range of doses (up to 20 mg/kg), TD001 achieved dose-dependent, potent tumor growth inhibition (TGI) not only in the high-PSMA LNCaP-abl CDX and C5 PDX models but also in the intermediate-PSMA 22Rv1 CDX model. Rapid responses and high TGI (>90%) after a single administration at optimal doses were seen across all models. Upon tumor regrowth, PSMA expression was unchanged between treated and vehicle control groups, indicating no impact on target expression. Recurrent tumors remained similarly responsive to rechallenge with TD001. Of note, fractionation of a single TD001 dose into 2 or 3 doses administered every 10 days resulted in persistent tumor regression (TGI ≥90% for 60-70 days) and extended survival compared to the equivalent higher single dose. TD001 was well tolerated with no body weight loss or other signs of toxicity, nor mortality at all doses after single and repeated dosing regimens. Alternative dosing schedules, dose response, and tumor/plasma ratio result in a 2-3 fold increase in therapeutic index (TGI ≥90% for up to 60 days). TD001 appears as a best-in-class anti-PSMA ADC with its novel linker-payload (LD038) and exhibits potent antitumor activity in preclinical models with a broad range of PSMA expression, representing a highly promising treatment for PSMA-expressing CRPC patients. The efficacy of TD001 in preclinical in vivo castrated CDX and PDX models supports further investigation in clinical settings. Daniela Impellizzieri, Elisa Storelli, Atik Balla, Simone Mosole, Cristina Dongilli, Federico Jauk, Roberta Frapolli, Lavinia Morosi, Maurizio D'Incalci, Jemila Houacine, Morris Rosenberg, Mohamed Bekradda, Esteban Cvitkovic, Carlo V. Catapano. Long-term tumor growth inhibition and extended survival with TD001, a novel optimized PSMA-targeting ADC, in PSMA-expressing CRPC CDX castrated mouse models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 311.

Cancer forms a local tumor that subsequently metastasizes to distant organs. In prostate cancer, the latter part of the trajectory is influenced by the inhibition of the androgen receptor (AR). The study of proteomic changes along disease progression may reveal insights into how prostate cancer evolves and open new therapeutic avenues. Here, we profile changes in protein abundance and post-translational modifications (PTMs) along the disease trajectory in patient-derived xenograft models. Our results suggest new therapeutic opportunities, such as USP1 inhibition and a key early involvement of the receptor tyrosine kinase (RTK)-RAS-mitogen-activated protein kinase (MAPK) pathway during disease progression. We highlight multiple alterations within the latter, including the tumor suppressors NF1 and ERF. Specific PTMs suggest changes in mitochondrial ATP synthesis, proteasomal activity, gene splicing, and transforming growth factor beta (TGF-β) signaling. Finally, we show how different transcription factors engage with disease progression. A web resource is provided, enabling the investigation of proteomic resources.

Mitochondrial dysfunction is a hallmark of cellular senescence. Here, we investigated whether senescent cells release mitochondrial (mt)DNA into the extracellular space and its impact on innate immunity. We found that both primary senescent cells and tumor cells undergoing therapy-induced senescence actively released mtDNA into the extracellular environment. mtDNA released by senescent cells was packaged within extracellular vesicles and selectively transferred to polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) in the tumor microenvironment. Upon uptake, extracellular mtDNA enhanced the immunosuppressive activity of PMN-MDSCs via cGAS-STING-NF-κB signaling, thereby promoting tumor progression. While STING activation directly induced NF-κB signaling, it also activated PKR-like endoplasmic reticulum kinase (PERK), which further amplified NF-κB activity, in PMN-MDSCs. mtDNA release from senescent cells was mediated by voltage-dependent anion channels (VDACs), and pharmacological inhibition of VDAC reduced extracellular mtDNA levels, reversed PMN-MDSC-driven immunosuppression, and enhanced chemotherapy efficacy in prostate cancer mouse models. These findings suggest that targeting mtDNA release could reprogram the immunosuppressive tumor microenvironment, improving therapeutic outcomes for chemotherapy-treated patients.

Tumor evolution is one of the major mechanisms responsible for acquiring therapy-resistant and more aggressive cancer clones. Whether the tumor microenvironment through immune-mediated mechanisms might promote the development of more aggressive cancer types is crucial for the identification of additional therapeutic opportunities. Here, we identify a subset of tumor-associated neutrophils, defined as tumor-associated neutrophil precursors (PreNeu). These PreNeu are enriched in highly proliferative hormone-dependent breast cancers and impair DNA repair capacity. Mechanistically, succinate secreted by tumor-associated PreNeu inhibits homologous recombination, promoting error-prone DNA repair through non-homologous end-joining regulated by PARP-1. Consequently, breast cancer cells acquire genomic instability promoting tumor editing and progression. Selective inhibition of these pathways induces increased tumor cell killing in vitro and in vivo. Tumor-associated PreNeu score correlates with copy number alterations in highly proliferative hormone-dependent tumors from breast cancer patients. Treatment with PARP-1 inhibitors counteract the pro-tumoral effect of these neutrophils and synergize with endocrine therapy.

AIMS:Cardiac fibrosis in response to injury leads to myocardial stiffness and heart failure. At the cellular level, fibrosis is triggered by the conversion of cardiac fibroblasts (CF) into extracellular matrix-producing myofibroblasts. miR-24-3p regulates this process in animal models. Here, we investigated whether miR-24-3p plays similar roles in human models. METHODS AND RESULTS:Gain- and loss-of-function experiments were performed using human induced pluripotent stem cell-derived cardiomyocytes (hCM) and primary hCF under normoxic or ischaemia-simulating conditions. hCM-derived extracellular vesicles (EVs) were added to hCF. Similar experiments were performed using three-dimensional human cardiac microtissues and ex vivo cultured human cardiac slices. hCF transfection with miR-24-3p mimic prevented TGFβ1-mediated induction of FURIN, CCND1, and SMAD4-miR-24-3p target genes participating in TGFβ1-dependent fibrogenesis-regulating hCF-to-myofibroblast conversion. hCM secreted miR-24-3p as EV cargo. hCM-derived EVs modulated hCF activation. Ischaemia-simulating conditions induced miR-24-3p depletion in hCM-EVs and microtissues. Similarly, hypoxia down-regulated miR-24-3p in cardiac slices. Analyses of clinical samples revealed decreased miR-24-3p levels in circulating EVs in patients with acute myocardial infarction (AMI), compared with healthy subjects. Post-mortem RNAScope analysis showed miR-24-3p down-regulation in myocardium from patients with AMI, compared with patients who died from non-cardiac diseases. Berberine, a plant-derived agent with miR-24-3p-stimulatory activity, increased miR-24-3p contents in hCM-EVs, down-regulated FURIN, CCND1, and SMAD4, and inhibited fibrosis in cardiac microtissues. CONCLUSION:These findings suggest that hCM may control hCF activation through miR-24-3p secreted as EV cargo. Ischaemia impairs this mechanism, favouring fibrosis.

Cancer stem cells (CSCs) are pervasively present in human cancers and have a fundamental role in treatment failure and disease recurrence. Identifying critical elements that sustain the CSC phenotype may lead to novel strategies for cancer treatment. Here, we provide evidence of an essential link between the σ1 receptor (σ1R), a ligand-regulated chaperone protein residing preferentially at the endoplasmic reticulum-mitochondria contact sites, and CSCs in castration-resistant prostate cancers (CRPCs). Integrating functional assays in multiple preclinical models with transcriptomic and proteomic data, we found that σ1R controls CSC self-renewal capacity and tumorigenic proficiency by coordinating mitochondrial dynamics and mitochondrial-nuclear signaling. Inhibiting σ1R with synthetic antagonists and RNA interference led to the progressive exhaustion and loss of tumorigenicity of the CSC progeny. Mechanistically, interfering with σ1R function disrupted mitochondria homeostasis and triggered β-catenin degradation. Examining clinical CRPC samples, we found a tight correlation between σ1R and mitochondrial gene expression. Furthermore, σ1R and β-catenin protein levels were highly correlated in prostate tumors with significant upregulation in metastatic CRPCs, sustaining a role of the σ1R-mitochondria-β-catenin axis in disease progression. This σ1R-centered axis is essential for preserving the self-renewal and tumorigenic capability of CSCs and represents a critical vulnerability exploitable for discovering novel CSC-directed therapies.

Phenotypic plasticity enables tumor progression and treatment resistance. However, its timing and underlying mechanisms are poorly understood. Here, we demonstrate that cell plasticity can emerge early during prostate cancer development, resulting from the knockout of the epithelial-specific ETS transcription factor EHF in prostate epithelial cells. Inspecting the transcriptome of human prostate cancers, we identified a correlation between low EHF expression, loss of luminal epithelial identity, and attenuated androgen signaling in both primary tumors and castration-resistant prostate cancers (CRPC). In EHF knockout mouse models and human epithelial cells, EHF ablation was sufficient to disrupt epithelial cell lineage integrity and promote a progenitor/stem cell-like state with both basal and luminal features, enabling high plasticity and multi-lineage phenotypic transitions. Mechanistically, EHF acted as a central node controlling a hierarchy of transcriptional regulatory factors and downstream signaling pathways (e.g., COL1A1/DDR1, JAK/STAT3), thereby regulating epithelial lineage integrity and restricting stemness and phenotypic transitions. Activation of these downstream pathways, consequent to EHF loss, promoted non-luminal cell features, attenuated androgenic response, and resistance to AR antagonists. Collectively, these data provide novel insights into the causes of phenotypic plasticity and androgen indifference already at the early stages of prostate tumorigenesis and a new perspective on the paths to cancer progression directly relevant to the development of more efficient treatment strategies. ### Competing Interest Statement The authors have declared no competing interest.

Cellular senescence can exert dual effects in tumors, either suppressing or promoting tumor progression. The senescence-associated secretory phenotype (SASP), released by senescent cells, plays a crucial role in this dichotomy. Consequently, the clinical challenge lies in developing therapies that safely enhance senescence in cancer, favoring tumor-suppressive SASP factors over tumor-promoting ones. Here, we identify the retinoic-acid-receptor (RAR) agonist adapalene as an effective pro-senescence compound in prostate cancer (PCa). Reactivation of RARs triggers a robust senescence response and a tumor-suppressive SASP. In preclinical mouse models of PCa, the combination of adapalene and docetaxel promotes a tumor-suppressive SASP that enhances natural killer (NK) cell-mediated tumor clearance more effectively than either agent alone. This approach increases the efficacy of the allogenic infusion of human NK cells in mice injected with human PCa cells, suggesting an alternative therapeutic strategy to stimulate the anti-tumor immune response in "immunologically cold" tumors.

Accumulating senescent cells within tissues contribute to the progression of aging and age-related diseases. Botanical extracts, rich in phytoconstituents, present a useful resource for discovering therapies that could target senescence and thus improve healthspan. Here, we show that daily oral administration of a standardized extract of Salvia haenkei (Haenkenium (HK)) extended lifespan and healthspan of naturally aged mice. HK treatment inhibited age-induced inflammation, fibrosis and senescence markers across several tissues, as well as increased muscle strength and fur thickness compared with age-matched controls. We also found that HK treatment reduced acutely induced senescence by the chemotherapeutic agent doxorubicin, using p16LUC reporter mice. We profiled the constituent components of HK by mass spectrometry, and identified luteolin-the most concentrated flavonoid in HK-as a senomorphic compound. Mechanistically, by performing surface plasmon resonance and in situ proximity ligation assay, we found that luteolin disrupted the p16-CDK6 interaction. This work demonstrates that administration of HK promotes longevity in mice, possibly by modulating cellular senescence and by disrupting the p16-CDK6 interaction.

Although hypercoagulability is commonly associated with malignancies, whether coagulation factors directly affect tumor cell proliferation remains unclear. Herein, by performing single-cell RNA sequencing (scRNA-seq) of the prostate tumor microenvironment (TME) of mouse models of castration-resistant prostate cancer (CRPC), we report that immunosuppressive neutrophils (PMN-MDSCs) are a key extra-hepatic source of coagulation factor X (FX). FX activation within the TME enhances androgen-independent tumor growth by activating the protease-activated receptor 2 (PAR2) and the phosphorylation of ERK1/2 in tumor cells. Genetic and pharmacological inhibition of factor Xa (FXa) antagonizes the oncogenic activity of PMN-MDSCs, reduces tumor progression, and synergizes with enzalutamide therapy. Intriguingly, F10high PMN-MDSCs express the surface marker CD84 and CD84 ligation enhances F10 expression. Elevated levels of FX, CD84, and PAR2 in prostate tumors associate with worse survival in CRPC patients. This study provides evidence that FXa directly promotes cancer and highlights additional targets for PMN-MDSCs for cancer therapies.

Castration-resistant prostate cancer (CRPC) is a frequently occurring disease with adverse clinical outcomes and limited therapeutic options. Here, we identify methionine adenosyltransferase 2a (MAT2A) as a critical driver of the androgen-indifferent state in ERG fusion-positive CRPC. MAT2A is upregulated in CRPC and cooperates with ERG in promoting cell plasticity, stemness and tumorigenesis. RNA, ATAC and ChIP-sequencing coupled with histone post-translational modification analysis by mass spectrometry show that MAT2A broadly impacts the transcriptional and epigenetic landscape. MAT2A enhances H3K4me2 at multiple genomic sites, promoting the expression of pro-tumorigenic non-canonical AR target genes. Genetic and pharmacological inhibition of MAT2A reverses the transcriptional and epigenetic remodeling in CRPC models and improves the response to AR and EZH2 inhibitors. These data reveal a role of MAT2A in epigenetic reprogramming and provide a proof of concept for testing MAT2A inhibitors in CRPC patients to improve clinical responses and prevent treatment resistance.

Mammalian outer radial glia (oRG) emerge as cortical progenitor cells that directly support the development of an enlarged outer subventricular zone (oSVZ) and, in turn, the expansion of the neocortex. The in vitro generation of oRG is essential to model and investigate the underlying mechanisms of human neocortical development and expansion. By activating the STAT3 pathway using LIF, which is not produced in guided cortical organoids, we developed a cerebral organoid differentiation method from human pluripotent stem cells (hPSCs) that recapitulates the expansion of a progenitor pool into the oSVZ. The structured oSVZ is composed of progenitor cells expressing specific oRG markers such as GFAP, LIFR, HOPX , which closely matches human oRG in vivo . In this microenvironment, cortical neurons showed faster maturation with enhanced metabolic and functional activity. Incorporation of hPSC-derived brain vascular LIF- producing pericytes in cerebral organoids mimicked the effects of LIF treatment. These data indicate that the cellular complexity of the cortical microenvironment, including cell-types of the brain vasculature, favors the appearance of oRG and provides a platform to routinely study oRG in hPSC-derived brain organoids.

Tumor cells promote the recruitment of immunosuppressive neutrophils, a subset of myeloid cells driving immune suppression, tumor proliferation, and treatment resistance. Physiologically, neutrophils are known to have a short half-life. Here, we report the identification of a subset of neutrophils that have upregulated expression of cellular senescence markers and persist in the tumor microenvironment. Senescent-like neutrophils express the triggering receptor expressed on myeloid cells 2 (TREM2) and are more immunosuppressive and tumor-promoting than canonical immunosuppressive neutrophils. Genetic and pharmacological elimination of senescent-like neutrophils decreases tumor progression in different mouse models of prostate cancer. Mechanistically, we have found that apolipoprotein E (APOE) secreted by prostate tumor cells binds TREM2 on neutrophils, promoting their senescence. APOE and TREM2 expression increases in prostate cancers and correlates with poor prognosis. Collectively, these results reveal an alternative mechanism of tumor immune evasion and support the development of immune senolytics targeting senescent-like neutrophils for cancer therapy.