Neoplasia

Glioblastoma remains a highly aggressive and therapy-resistant brain tumor, with limited benefit from the current standard-of-care regimen combining surgery, radiotherapy, and temozolomide. Overcoming chemoresistance therefore represents a critical unmet clinical need. Here, we investigate the anticancer potential of Succisa pratensis and its ability to enhance TMZ efficacy in GBM models. Treatment with S. pratensis markedly reduced cell proliferation and migration while significantly increasing sensitivity to TMZ. Integrated multi-omics analyses revealed extensive metabolic rewiring, characterized by suppression of central carbon metabolism and activation of stress-adaptive pathways. Mechanistically, we identify the Pregnane X Receptor, a key regulator of drug metabolism and chemoresistance, as a central node affected by treatment. Although S. pratensis increased PXR expression, this was not accompanied by induction of canonical downstream targets, including MDR1 and ALDH1A1, indicating a functional impairment of PXR transcriptional activity. Consistently, pharmacological inhibition of PXR using the antagonist SPA70 further potentiated the cytotoxic effects of S. pratensis and TMZ. Docking analyses suggest that specific secondary metabolites, including apigenin-derived compounds, may interact with the PXR ligand-binding domain, providing a potential molecular basis for this effect. Collectively, our findings indicate that S. pratensis enhances TMZ efficacy by inducing metabolic vulnerability and functionally impairing PXR signaling. These results highlight the therapeutic potential of plant-derived metabolites as adjuvant strategies to overcome chemoresistance in glioblastoma. Article HighlightsO_LISuccisa pratensis enhances temozolomide efficacy in glioblastoma by reducing proliferation, migration, and clonogenic growth. C_LIO_LIIntegrated proteomic and metabolomic analyses reveal extensive metabolic rewiring, with suppression of central carbon metabolism and induction of stress-adaptive pathways. C_LIO_LIPregnane X Receptor (PXR), a key regulator of chemoresistance, is functionally impaired despite increased expression, resulting in reduced activation of drug-resistance genes. C_LIO_LIPharmacological inhibition of PXR further potentiates the antitumor effects of Succisa pratensis and temozolomide, promoting apoptotic cell death. C_LIO_LIApigenin-derived metabolites show high affinity for the PXR ligand-binding domain and emerge as promising candidates to overcome temozolomide resistance in glioblastoma. C_LI

Background/ObjectivesGlioblastoma is an aggressive primary brain tumor that develops within a chronically low-oxygen microenvironment, yet most preclinical studies are performed under atmospheric oxygen conditions that poorly reflect in vivo physiology. This study investigated how sustained culture under physiological oxygen tension (physioxia; 5% O{square}) influences glioblastoma cell behavior, signaling, and therapeutic response. MethodsMultiple patient-derived glioblastoma models were cultured under normoxia (21% O{square}) or sustained physioxia (5% O{square}) for at least seven days before experimentation. Cell migration, proliferation, cell cycle distribution, expression of the epithelial-to-mesenchymal transition-associated transcription factor Slug (SNAI2), PDGFR{beta}-associated signaling, and sensitivity to 5-fluorouracil were evaluated using transwell migration assays, cell counting, flow cytometry, RT-qPCR, immunoblotting, and BrdU incorporation assays. Additional patient-derived cultures established and maintained continuously under physioxia were used to examine the effects of oxygen history. ResultsSustained physioxia consistently increased migration across all glioblastoma models while reducing proliferation in normoxia-adapted cell lines through increased G0/G1 cell cycle arrest. Physioxia significantly increased Slug expression in all models and enhanced PDGFR{beta}, AKT, and ERK phosphorylation in a cell line-dependent manner. Therapeutic sensitivity to 5-fluorouracil was also altered, with physioxia conferring increased resistance in selected glioblastoma models but not universally. Patient-derived cultures maintained continuously under physioxia retained enhanced migratory capacity and exhibited increased proliferation compared with normoxia, indicating that prior oxygen exposure influences proliferative responses while the pro-migratory phenotype remains conserved. ConclusionsPhysiological oxygen tension is a major regulator of glioblastoma cell behavior, influencing migration, proliferation, signaling, and therapeutic response. These findings demonstrate that conventional normoxic culture conditions can obscure biologically relevant phenotypes and support incorporating physioxia into experimental design to improve the physiological and translational relevance of preclinical glioblastoma research.

BackgroundDysregulated cell migration leading to metastasis remains the primary cause of cancer-related mortality. It has been challenging to understand how cells regulate migration. We have previously created the first selective inhibitor of cell migration, KBU2046. Here, we use it as a probe to identify regulatory processes. MethodsMetastatic and primary human prostate cancer cells were treated for different times and at different concentrations with KBU2046. Immunofluorescent microscopy examined protein localization in cells. Label-free mass spectrometry (MS) was performed on total cell proteins, Tandem Mass Tag (TMT) labeling MS was used on membrane fractions, and temporal phosphoproteomic profiling. Results were analyzed with a suite of bioinformatic tools. ResultsKBU2046-induced migrastasis is associated with the accumulation of activated integrin {beta}1 into focal adhesions. Whole-cell proteomics demonstrated suppression of processes that mediate intracellular protein trafficking and increases in mitochondrial energy-generation signatures. Evaluation of the membrane fraction identified increases in membrane repair and maintenance processes and decreases in those that drive motility. Temporal- and concentration-dependent phosphoproteomic profiling revealed that KBU2046 initiates a dynamic, cascading sequence of transient signaling waves rather than a static block. ConclusionsKBU2046-induced migrastasis appears to operate through spatial decoupling rather than structural degradation. By restricting the intracellular trafficking machinery required for receptor recycling, KBU2046 limits focal adhesion turnover, providing a correlative framework to inhibit metastatic dissemination independent of direct cytotoxicity. O_FIG O_LINKSMALLFIG WIDTH=122 HEIGHT=200 SRC="FIGDIR/small/736165v1_ufig1.gif" ALT="Figure 1"> View larger version (39K): org.highwire.dtl.DTLVardef@1cc69d3org.highwire.dtl.DTLVardef@137b843org.highwire.dtl.DTLVardef@1225e50org.highwire.dtl.DTLVardef@15dd8d2_HPS_FORMAT_FIGEXP M_FIG Graphic Abstract C_FIG

177Lu-PSMA-617 (PluvictoTM, Lu-177 RLT) is an FDA-approved targeted radioligand therapy (RLT) for metastatic castration-resistant prostate cancer (mCRPC), but its durability of response to this singular approach poses a challenge to the field. Chimeric antigen receptor (CAR) T cell therapy has revolutionized clinical practice for hematological malignancies, but its clinical development for solid tumors, including mCRPC, has been encumbered by antigen heterogeneity and the immunosuppressive tumor microenvironment (TME). Here, we evaluate the therapeutic combination of Lu-177 RLT and PSCA-CAR T cells to overcome these barriers. In human xenograft and mouse syngeneic prostate cancer models with homogeneous or heterogeneous antigen expression, the sequential administration of Lu-177 RLT, cyclophosphamide (Cy), and PSCA-CAR T cells improves tumor control and prolongs survival compared to monotherapies. Mechanistically, Lu-177 RLT alone or with Cy remodels the TME by promoting pro-inflammatory myeloid responses and activating endogenous T cells, while enhancing CAR T cell activation and effector function. We additionally evaluated 225Ac-PSMA-617 RLT as an emerging approach in combination with CAR T cells and observed anti-tumor responses, supporting its potential as an alternative RLT partner. These findings support RLT as an immune priming strategy to enhance CAR T cell therapy and provide a rationale for clinical translation of this combination in mCRPC. One Sentence SummaryCombining 177Lu-PSMA-617 radioligand therapy with PSCA-CAR T cells improves tumor control and survival in prostate cancer models by overcoming the antigen heterogeneity and reshaping the immunosuppressive tumor microenvironment.

Canine hemangiosarcoma (HSA) is an aggressive endothelial malignancy with limited therapeutic options, and its progression is closely associated with vascular architecture, stromal remodeling, and inflammatory cell recruitment. Sulfoquinovosylacylpropanediol (SQAP) is a sulfoquinovosyl lipid radiosensitizer reported to affect angiogenic and tumor-microenvironmental pathways, but its effects in canine HSA are unknown. Here, we evaluated SQAP in canine HSA cell lines and patient-derived xenograft (PDX) models. SQAP showed minimal direct cytotoxicity against HSA cell lines in vitro, whereas it significantly suppressed tumor growth in three canine HSA PDX models. Transcriptome analysis of SQAP-treated HSA PDX tumors detected more SQAP-responsive genes in mouse host-derived cells than in canine tumor cells. Gene-set enrichment analysis of the mouse host-derived fraction showed positive enrichment of angiogenesis, hypoxia, and stromal remodeling-related gene sets after SQAP treatment. Subsequent tissue analysis showed that SQAP reduced host-derived CD31-positive vascular area and increased -smooth muscle actin coverage of remaining vessels in two of the three PDX models, while altering macrophage-associated marker profiles in a model-dependent manner. These findings indicate that SQAP suppresses canine HSA PDX growth primarily through vascular and macrophage-associated remodeling of the tumor microenvironment rather than direct tumor-cell cytotoxicity.

Glioblastoma (GBM) is a highly lethal brain cancer with limited therapeutic durability, where the majority of patients develop recurrent or persistent disease after standard chemoradiotherapy. Meanwhile, tRNA-derived fragments (tRFs) have become increasingly relevant to cancer biology; however, their clinical relevance in GBM remains undefined. Here, we report that a specific family of tRFs, 5-tRNA halves (tiR5s) dominates the small RNA landscape of GBM patient tumors and associates with worse overall survival, post-therapeutic disease persistence, and pro-invasive proteogenomic pathways across two independent GBM patient cohorts. This association between elevated tiR5 levels and therapeutic resistance re-emerges in radiation-resistant GBM xenograft models. Our findings reveal that tiR5s are an underappreciated molecular feature of highly aggressive GBM tumors, supporting further investigation into their biological roles and prognostic utility in GBM. HighlightsO_LItiR5s are the predominant tRF family in primary GBM patient tumors C_LIO_LIElevated tiR5 expression distinguishes primary GBM tumors that develop persistent disease after first-line therapy C_LIO_LIRadiation-resistant GBM PDX models show elevated tiR5 expression C_LIO_LIElevated tiR5 expression associates with poor overall patient survival and pro-invasive molecular programs in GBM patient tumors C_LI Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=200 SRC="FIGDIR/small/738483v1_ufig1.gif" ALT="Figure 1"> View larger version (54K): org.highwire.dtl.DTLVardef@184ddc1org.highwire.dtl.DTLVardef@1faadc2org.highwire.dtl.DTLVardef@a5ae02org.highwire.dtl.DTLVardef@1431506_HPS_FORMAT_FIGEXP M_FIG C_FIG

Background: Medulloblastoma (MB) is the most common malignant brain tumour in children, and aggressive subgroups are frequently driven by the oncoproteins MYC or MYCN. Direct therapeutic targeting of MYC/MYCN has been challenging because of their intrinsically disordered protein structures. The aim of this study was to determine whether novel SE486-11 analogues (UNSW-SCs) can therapeutically target MYC/MYCN-driven MB. Methods: The anticancer activity of UNSW-SCs was assessed in MB cell lines with differential MYC/MYCN expression. Target engagement was evaluated using surface plasmon resonance and drug affinity responsive target stability assays. Blood-brain barrier penetration, MYC/MYCN protein degradation, cell cycle effects, apoptosis, DNA damage, and synergy with histone deacetylase (HDAC) inhibitors were examined. Therapeutic efficacy was evaluated in murine models of MYC- and MYCN-driven human MB. Results: UNSW-SCs showed potent anticancer activity, with preferential selectivity toward MB cells expressing high MYC/MYCN levels and IC50 values ranging from 0.22 to 1.18 M. The lead molecule, UNSW-SC-22, directly bound MYC, crossed the blood-brain barrier, and achieved a brain-to-plasma ratio of 1.44 at peak concentrations. UNSW-SC-22 induced MYC/MYCN-dependent cytotoxicity associated with enhanced proteasomal degradation, cell cycle arrest, apoptosis, and DNA damage. Combined treatment with HDAC inhibitors further reduced MYC/MYCN protein levels, increased DNA damage, and enhanced apoptosis. In vivo, UNSW-SC-22, either alone or with entinostat, significantly suppressed intracranial tumour growth and prolonged survival. Conclusions: UNSW-SC-22 is a brain-penetrant MYC/MYCN-targeting molecule with potent preclinical activity in MYC/MYCN-driven MB, supporting its development as a monotherapy or combination strategy with HDAC inhibition.

Malignant brain tumors are among the most aggressive and difficult to treat human cancers. Glioblastomas (World Health Organization grade IV gliomas) are particularly lethal and refractory to treatment. Few drugs exist that are even somewhat effective. Our investigation of the physiologic role of fatty acid (FA) activating enzymes (acyl-CoA synthetase; ACS) identified an ACS that was widely expressed in gliomas but not in normal glial cells. Depletion of this enzyme, ACSVL3 (very long-chain ACS3), by knockdown or knockout decreased the malignant behavior of several glioma cell models including U87MG and Mayo-22 cells both in culture and when grown as xenografts. Hypothesizing that ACSVL3 is a potential therapeutic target in glioma, we conducted a search for inhibitors of this enzyme and found that CB5 (grassofermata) was a promising candidate. Treating U87MG glioma cells with CB5 slowed growth in monolayer culture; the growth rate was similar to that seen in cells in which ACSVL3 was either knocked down or knocked out. CB5 inhibited growth in a dose-dependent manner over a narrow range, and concentrations above 10 M were toxic. Treatment at the lower dose of 3 M inhibited growth of U87MG cells but was reversible, suggesting that this dose was not toxic. CB5- treated U87MG cells exhibited an altered morphology with a larger size and longer projections. In contrast, normal human fibroblasts treated with 10 M CB5, a concentration that was toxic to U87MG cells, showed no effect on either growth rate or morphology. Treating U87MG cells with 3 M CB5 induced differentiation as shown by increased expression of the astrocyte-specific marker glial fibrillary acidic protein (GFAP). In contrast, GFAP levels remained low in ACSVL3 knockdown cells. CB5- treated U87MG cells were less invasive, and thus less malignant, than either untreated cells or ACSVL3 knockout cells when assessed by a scratch wound healing assay. Acute treatment of U87MG cells with 3 M CB5 decreased the ability of these cells to degrade FA of differing chain lengths from 16-24 carbons by {beta}-oxidation, suggesting that decreased ACS enzyme activity contributes at least in part to the drugs mechanism of action. NOD/SCID mice receiving up to 32 mg/kg/day CB5 by intraperitoneal injection showed no obvious side effects, suggesting that the drug was well-tolerated. Xenografts induced by subcutaneous injection of U87MG cells in the flanks of NOD/SCID mice were allowed to grow for 8 days after which half of the mice were treated with 2 mg/kg/day CB5. After 7 days of treatment, xenograft growth slowed in the treated mice and by 12 days tumor size had begun to decrease, suggesting therapeutic efficacy. When a similar study was done using xenografts induced by subcutaneous injection of Mayo-22 cells, which are maintained as subcutaneous tumors in mice rather than in cell culture, the effect of CB5 on tumor growth or weight at sacrifice was not statistically significant. The results of these studies suggest that CB5 may have therapeutic value in malignant glioma. Additional studies using other glioma models and other drugs chemically related to CB5 seem warranted.

Patient-derived organoids (PDOs) have transformed translational cancer research, allowing tractable models that better represent clinical features than traditional immortalized cell lines. Here we describe two PDOs with differential responses to carboplatin derived from sequential ascites fluid collections from a patient with high-grade mullerian carcinoma, that could not be further subclassified on the omental biopsy. Uterine origin was clinically excluded by pelvic imaging/CT scan of the uterus and absence of vaginal bleeding. Successful derivation from independent collections enabled comparison of intra-patient heterogeneity across sequential ascites samples and demonstrates that PDO efficiency rate is at least partly patient-specific or tumor-dependent. We performed long-read whole genome sequencing on the two PDOs, OC104 and OC109, to better characterize the structural variant landscape while also obtaining information on single nucleotide variants and DNA methylation. In addition to confirming single nucleotide variants noted in clinical sequencing (TP53, KRAS, SPOP, PPP2R1A, KMT2D), we identified additional variants in TSC2, NCOR2, and CTNNA2 that are predicted to be likely pathogenic. The spectrum of mutations, particularly the coincident KRAS and TP53, highlighted unexpected overlap with ovarian mucinous carcinoma. We also identified larger insertions and deletions that result in non-synonymous variants in MUC5AC, TPRX1, and BMX, as well as four translocation events, including two that could not have been resolved with short-read sequencing. Differentially methylated promoters between the two PDOs include 201 oncogenes and tumor suppressor genes, with HNF1A, MSI2, and SETBP1 having methylation directions consistent with these genes' roles in platinum response differences observed between the PDOs. Notably, the clonal nature of PDOs produced from two samples taken one week apart is important for the field to appreciate, particularly since they have clonal differences in platinum response. The temporal differences in clonality may indicate a limitation of low volume sampling, however may provide opportunity to longitudinally predict clinical outcomes. We also demonstrate the ability of long-read sequencing to add detail into the genomics and epigenetics of ovarian cancer.

Pancreatic cancer (PC) exhibits a striking association with depression, with neuropsychiatric symptoms frequently preceding diagnosis. However, the biological mechanisms linking pancreatic tumor development to central nervous system dysfunction remain poorly understood. Here, we investigated the impact of PC progression on adult hippocampal neurogenesis using complementary orthotopic xenograft and genetically engineered mouse models. Tumor-bearing mice developed depressive-like behavioral abnormalities accompanied by reduced adult hippocampal neurogenesis, including depletion of neural stem cell populations and immature neurons in both dorsal and ventral dentate gyrus regions. In the genetic model, neurogenic impairment progressed in parallel with disease severity. Exposure of primary hippocampal neural stem cells to serum derived from tumor-bearing mice selectively impaired cell survival, indicating that circulating factors are sufficient to compromise neurogenic capacity. Consistent with this, cytokine profiling revealed profound systemic inflammatory alterations, with IL-6 emerging as the only cytokine consistently elevated across both models. Together, our findings identify disruption of the adult hippocampal neurogenic niche as a previously unrecognized consequence of pancreatic cancer progression and provide a biological framework for pancreatic cancer-associated depression.

PurposeCisplatin (CDDP) is the most active chemotherapy for ovarian cancer; primary or acquired resistance signals a poor prognosis. Nelfinavir (NFV), an HIV protease inhibitor, has demonstrated anti-tumor activity in multiple cancer models, but its interaction with CDDP in ovarian cancer has yet to be demonstrated. In this work, we addressed whether the combination of CDDP and NFV provides treatment advantage in platinum (Pt)-resistant ovarian cancer cells. MethodsDrug synergy between NFV and CDDP was assessed using cell vitality assays and Loewe additivity modelling. Apoptotic and pyroptotic signalling were evaluated by immunoblotting, mitochondrial membrane potential analysis, and lactate dehydrogenase (LDH) release, and caspase inhibition. Transcriptomic changes were assessed by bulk mRNA sequencing followed by differential gene expression analysis and gene set enrichment analysis. ResultsNFV synergized with CDDP to reduce the viability of Pt-resistant ovarian cancer cells, promoting a regulated lytic cell death phenotype involving apoptotic and pyroptotic features. Combination treatment induced caspase-8 and caspase-3 activation, and downstream gasdermin E (GSDME) processing. Inhibition of caspase-3 significantly attenuated cell death, and caspase-8 inhibition rescued viability and prevented Bid cleavage, caspase-3 activation, and GSDME cleavage. These effects occurred in the context of enhanced endoplasmic reticulum stress, increased DNA damage with reduced DNA repair, and impaired Akt-driven survival signalling. ConclusionsOur findings establish that NFV synergizes with CDDP in killing Pt-resistant ovarian cancer cells by promoting a caspase-8-dependent apoptotic-to-secondary pyroptotic response, supporting further investigation of NFV as a potential drug to be repurposed to increase the efficacy of Pt-based therapy.

Polo-like kinase 1 (PLK1), a key regulatory protein controlling entry into and passage through mitosis, has been targeted through its kinase domain (KD) with mixed clinical success. Inhibition through the Polo-box domain (PBD) is a viable alternative through targeting the sub-cellular localization and kinase activity of PLK1. Novel non-peptidic compounds, termed abbapolins, were discovered through the REPLACE strategy and have been lead optimized through structure-based strategies and screening analogs in the NCI-60 tumor cell panel. Proteomic analysis revealed a correlation between abbapolin activity and PLK1 protein levels in the cell lines part of the NCI-60. Prostate cell lines were identified as among the most sensitive and led to further detailed studies of their activity in prostate cancer models. Compounds were evaluated for their pharmacokinetic properties, and in vivo efficacy, and results showed significant antitumor xenograft activity with no observable gross toxicity. Treated tumors were analyzed for loss of PLK1, which was previously shown to be induced by abbapolin binding. Results obtained showed a significant degradation of PLK1 in abbapolin-treated vs untreated tumors, thereby confirming on-target action in vivo and revealing PLK1 levels as a potential pharmacodynamic marker. Lead compounds were shown to sensitize PC tumors resistant to androgen deprivation therapy paving the way for future combination studies in vivo. These data provide an alternative pathway for effective PLK1 therapeutics that avoid the reported problems of molecules targeting the KD, in vivo proof-of-concept for the REPLACE strategy and validation for targeting the PBD as an anti-tumor drug development strategy.

Ferroptosis, an intracellular iron-catalyzed form of programmed cell death (PCD) driven by lipid reactive oxygen species induced membrane damage, is mechanistically uncharacterized in its execution process. Here, we investigated ferroptosis execution in mesenchymal-like ovarian cancer cells treated with ferroptosis inducers ML162 and erastin. We showed that YVAD (a pyroptosis-associated inflammatory caspase inhibitor) and disulfiram (preventing gasdermin pore formation on plasma membrane) deterred ferroptotic cell death. Moreover, we also observed LDH release and IL-1{beta} secretion from ferroptotic cells, suggesting that ferroptosis involves a pore-forming process. Intriguingly, ferroptosis is independent of the canonical inflammasome pathway because caspase-1 is dispensable and not activated upon ferroptosis induction. In contrast, we found that caspase-5 was activated while caspase-4 was not during ferroptosis. In addition, depletion of caspase-5 rendered cells not responding to ferroptosis inducers. Also intriguingly, GSDMD, the well-established caspase-5 substrate, was not involved in ferroptosis. We instead detected GSDME cleavage upon ferroptosis induction and knockdown of GSDME reduced cell death induced by ferroptosis inducers. As caspase-5 activity was necessary for ferroptosis and caspase-5 directly cleaved GSDME, we conclude that the axis of caspase-5/GSDME executes ferroptosis in ovarian cancer cells.

BackgroundTumor-associated neutrophils (TANs) are emerging as functionally heterogeneous and plastic cells in the tumor microenvironment. In immunologically cold tumors, elevated neutrophil abundance correlates with poor prognosis and resistance to immune checkpoint inhibition (ICI). Whether distinct anti-tumoral neutrophil states can be induced by different immunotherapies and how they relate to treatment efficacy remains unclear. MethodsUsing the syngeneic MOC2-huEGFR (M2h) mouse model of head and neck squamous cell cancer (HNSCC), we treated tumor-bearing mice with agonistic anti-CD40 monoclonal antibody (mAb) (aCD40), TNF, Cetuximab, or a combination of all three, designated Neutrophil Activating Therapy (NAT). In addition to evaluating anti-tumor efficacy, we performed single-cell multiomics RNA and protein sequencing, followed by bioinformatics analyses and flow cytometry validation. NAT-induced anti-tumor efficacy and related neutrophil states were also assessed in another cold tumor model, 9464D-GD2 neuroblastoma. Murine treatment-induced neutrophil gene signatures were then evaluated using clinical, proteomic, and transcriptomic data from HNSCC patients. ResultsFive transcriptionally distinct neutrophil states (N0-N4), including precursor state CD49d+ N4, were identified using the M2h model. N0 neutrophils (immunosuppressive/quiescent) dominated untreated tumors, but not in successful treatments. ISG+ N1 neutrophils and CCR3+ N3 neutrophils expanded by aCD40, TNF, and NAT treatment with anti-tumoral gene signatures and found more interacting with CD8+ T cells from bioinformatics analysis. N2 neutrophils reflected a recently established hypoxia-adapted state found in all treatments. ICAM1 (CD54) emerged as a marker of treatment-induced neutrophil activation, discriminating N1, N2, and N3 neutrophils from N0 neutrophils, validated by flow cytometry. In the 9464D-GD2 neuroblastoma model, NAT treatment also reduced the N0 dominance seen in untreated tumors in the HNSCC model but failed to induce anti-tumoral neutrophil states. In 23 HNSCC patients who received ICI therapy, ICAM1 protein expression in neutrophils trended toward association with responder status (TMA-level p=0.029), and ICAM1 neutrophil gene expression also trended toward association with improved overall survival in TCGA data (HR=0.75, p=0.059). ConclusionsDistinct immunotherapy-induced neutrophil states are defined by transcriptional profiles enriched in different functional pathways, associated with both anti-tumor and pro-tumor signatures. ICAM1 identifies activated neutrophils and potentially serves as a biomarker of ICI response in HNSCC, warranting further clinical validation. WHAT IS ALREADY KNOWN ON THIS TOPICNeutrophil heterogeneity has received increasing attention, with studies identifying antitumoral neutrophil populations, either at baseline or induced by treatment. Several effective treatment regimens involve an anti-CD40 agonist (aCD40) antibody, among them Neutrophil Activating Therapy (NAT), which combines aCD40, TNF, and a tumor antigen binding antibody designed to reprogram neutrophils. NAT could thus be particularly effective in cold, myeloid-rich tumors that are largely unresponsive to conventional immunotherapies such as checkpoint blockade, enacting these anti-tumoral effects through similar and different mechanisms; however, this has not been tested. WHAT THIS STUDY ADDSThis study adds a single-cell multi-omics framework for defining treatment-induced neutrophil heterogeneity in MOC2-huEGFR and 9464D-GD2 tumors, two immunologically cold models. It highlights ICAM1/CD54 and interferon-stimulated genes as markers of a dominant antitumor neutrophil state, while showing that neutrophil state composition variy across tumor models. HOW THIS STUDY MIGHT AFFECT RESEARCH, PRACTICE, OR POLICYThese results support the efficacy of a myeloid-modulating therapy built around aCD40 and TNF in a cold murine head and neck cancer model, and to a lesser extent in a cold murine neuroblastoma model. ICAM1/CD54 expression in neutrophils was also identified as a promising marker of antitumor activity and treatment response. More broadly, this work suggests that incorporating aCD40 and/or TNF into existing treatment regimens could improve outcomes, while ICAM1/CD54-high neutrophils may serve as a useful therapeutic readout.

High-grade serous carcinoma (HGSOC) is the deadliest subtype of ovarian cancer, characterized by high metastatic rates. HGSOC is typically diagnosed at late stages, and treatment options are limited, resulting in a 60% recurrence rate. HGSOC cells exhibit metabolic plasticity, dynamically shifting between glycolysis and oxidative phosphorylation (OXPHOS) to meet energy demands for tumor progression. To evaluate therapeutic strategies that target metabolic vulnerabilities, we developed a microphysiological system (MPS) that recapitulates the heterogenous cell states and bioenergetic distribution of HGSOC solid tumors. Our platform utilized HGSOC spheroids embedded in a collagen hydrogel that mimics the extracellular matrix to capture tumor progression in the ovary. We used atovaquone (ATO), an FDA-approved OXPHOS inhibitor, to prototype the capabilities of our platform to investigate metabolic plasticity in HGSOC. Treatment with ATO decreased viability and invasion of HGSOC spheroids. Crucially, ATO exhibited no cytotoxicity toward biomimetic blood vessels, preserving their integrity and permeability. Metabolic imaging revealed that ATO induces an oxidative state in the outer region of the spheroids. At the invasive front, ATO disrupted mitochondrial organization, forcing collective cell migration and eventually inducing breakdown of mitochondrial networks. Furthermore, ATO decreased YAP/TAZ pathway activity in the outer region of the spheroid, providing a potential mechanism for hindered cell invasion. Collectively, our data demonstrates that a low-potency OXPHOS inhibitor like ATO can effectively target metabolic plasticity to suppress HGSOC spheroid progression. Overall, this platform successfully recapitulated metabolic heterogeneity and provided a workflow for safely testing other drugs that target cancer metabolism.

BackgroundDiffuse midline glioma (DMG) is a lethal pediatric brain tumor driven by the H3K27M oncohistone, which disrupts epigenetic regulation and promotes tumor proliferation. While prior studies show that H3K27M is essential for tumor initiation, its role in established tumors, tumor microenvironment (TME) regulation, and therapeutic response remain unclear. MethodsHere, we developed inducible and reversible H3.3K27M and H3.1K27M cell and mouse models to study oncohistone-dependent effects on tumor growth, recurrence, and the immune/stromal microenvironment. We generated a tetracycline-inducible PiggyBac-based oncohistone expression cassette in patient- and murine-derived models and validated inducible and reversible H3K27M expression. ResultsRe-expression of H3K27M in knockout cells induced morphological changes and suppressed astrocytic markers. Chromatin accessibility profiling revealed distinct states between ON, OFF, and OFF-ON groups, including PD1-mediated immunosuppressive mechanisms associated with H3K27M expression. Single-cell RNA sequencing demonstrated that the oncohistone reshapes the TME. H3K27M expression promotes tumor-neuron interactions, enhances neuronal excitability, excitatory/inhibitory imbalance, and synaptic connectivity that supports tumor proliferation. These effects are associated with increased glutamatergic signaling and enhanced tumor-neuron coupling through glutamate transport and receptor pathways, including EAAT1 (SLC1A3) and AMPARs (GRIA3). Conversely, H3K27M inhibition reduces neuronal excitation, disrupts tumor-associated signaling, and partially restores neuron-neuron and neuron-immune communications. These findings identify H3K27M as a key driver of excitatory neuron-to-tumor coupling and immunosuppression in DMG. ConclusionsOverall, our findings demonstrate that H3K27M extensively reshapes TME in DMG and support direct oncohistone targeting as a potential therapeutic strategy, including potential CRISPR-based or small-molecule approaches for patients with H3K27M-mutant DMG. Key PointsO_LIWe developed inducible and reversible H3K27M DMG models to investigate the role of H3K27M in the tumor microenvironment. C_LIO_LIH3K27M promotes tumor-neuron communication, while its inhibition disrupts these interactions, supporting H3K27M-targeted therapies for DMG. C_LI Importance of StudyDiffuse midline glioma (DMG) remains one of the deadliest pediatric brain tumors, with limited effective treatment options and poor patient survival. Although the H3K27M oncohistone is recognized as a key driver of tumor initiation, its role in maintaining tumor progression and shaping the tumor microenvironment is unclear. In this study, we developed inducible and reversible H3.3K27M and H3.1K27M murine and patient-derived DMG cell- and mouse-models that enabled precise control of the oncohistone expression. Using these models, we demonstrate that H3K27M actively promotes tumor-neuron interactions, neuronal excitability, and glutamatergic signaling pathways that support tumor growth. Importantly, inhibition of H3K27M disrupted these tumor-associated signaling networks and partially restored neuron-immune communication within the tumor microenvironment. Together, these findings demonstrate that H3K27M extensively reshapes the tumor microenvironment in these Diffuse Midline Gliomas and provides strong rationale for directly targeting the oncohistone as a therapeutic strategy for patients with H3K27M-mutant DMG. Lay SummaryDiffuse Midline Glioma (DMG) is a devastating childhood brain cancer. Despite decades of research, radiation remains the primary treatment and provides only temporary benefit. Most DMGs carry a mutation called H3K27M, which is an attractive target for new treatments such as directly inhibiting or removing this mutation using gene-editing. However, it remains unclear whether inhibiting H3K27M alone will be sufficient to stop the growth of established tumors. In this study, we developed human and mouse models that allow H3K27M to be turned on and off. We found that H3K27M helps tumors communicate with surrounding cells, particularly neurons. Inhibiting H3K27M disrupted tumor-promoting interactions and partially restored normal communication, supporting direct H3K27M-targeted therapies as a promising strategy for children with DMG.

Background: High ambient temperature in early pregnancy has been linked to an increased risk of childhood acute lymphoblastic leukemia (ALL). To better understand biological mechanisms, the current study evaluated potential interaction between temperature and genetic characteristics. Methods: We used data from California birth records (1982-2008) and California Cancer Registry (1988-2011) to identify ALL cases (n=3,353) diagnosed <=14 years of age and non-cancer controls (n=3,530) matched 1:1 on sex, race, ethnicity, and birth year and month. Weekly ambient temperatures throughout pregnancy were assessed on a 1-km grid around the birth address, while genetic data were available from a genome-wide association study using neonatal blood spots. We evaluated the association between ambient temperature and ALL risk by quartiles of established genetic risk score for ALL. Next, we formally tested gene-temperature interactions in the association with ALL, correcting for multiple testing, for genes previously identified with epigenetic changes due to both temperature and ALL. All analyses were adjusted for potential confounders. Results: The elevated risk of ALL per 5 degrees C increase of weekly mean ambient temperature, confined to early pregnancy, was more pronounced among children with the lowest genetic susceptibility to ALL, especially among Latino children (first quartile: odds ratio [OR] = 1.50, 95% confidence interval [CI]: 1.14-1.97); fourth quartile: OR=1.03, 95% CI: 0.83-1.28). There were significant interactions (p<0.002) between ambient temperature and polymorphisms in BNC1 among non-Latino White children, and suggestive interactions (p<0.05) with TBPL2 and NRXN1 in the full population. Conclusions: Our findings suggest that there may be interactions between ambient temperature in early pregnancy and offspring genotype in the risk of childhood ALL. Impact: If replicated, these findings could help elucidate the biological mechanisms linking high ambient temperature in early pregnancy and the risk of childhood ALL.

Bipolar androgen therapy (BAT) exploits the paradoxical vulnerability of castration-resistant prostate cancer (CRPC) cells to rapid cycling between castrate and supraphysiologic androgen concentrations, but clinical BAT uses testosterone, which can also activate wild-type androgen receptor (AR) in androgen-responsive tissues, causing systemic side effects. 5{beta}-dihydrotestosterone (5{beta}-DHT) is a naturally occurring testosterone metabolite generally considered androgenically inactive because it binds wild-type AR weakly, yet its activity against clinically relevant AR mutants has not been systematically evaluated. Here, we tested whether 5{beta}-DHT and related 5{beta}-reduced testosterone metabolites activate AR signaling and growth programs in prostate cancer models that carry AR mutations. In C4-2 cells, 5{beta}-DHT and 3{beta}-etiocholanediol (3{beta}-ecdiol) increased canonical AR target genes, including KLK3 and TMPRSS2, with weaker activity than testosterone, whereas other 5{beta} metabolites showed limited activity. In androgen-responsive LNCaP and C4-2 models, 5{beta}-DHT and 3{beta}-ecdiol promoted cell growth under androgen-depleted conditions, and this effect was suppressed by enzalutamide, supporting AR dependence. RNA-seq confirmed that 5{beta}-DHT and 3{beta}-ecdiol induced androgen-response gene sets substantially overlapping with testosterone, albeit at lower transcriptional magnitude. Further, we found that 5{beta}-DHT, but not 3{beta}-ecdiol, suppresses cell proliferation of LNCaP, C4-2, and PC-3 cells stably expressing the clinically relevant AR gain-of-function mutants W742C and H875Y through activating AR-induced senescence-like features after high-dose exposure, consistent with the therapeutic logic of BAT. These findings identify 5{beta}-DHT as an overlooked mutant-AR agonist capable of BAT-like tumor suppression and propose it as a testosterone surrogate in BAT with potentially reduced systemic androgenic side effects. HighlightsO_LI5{beta}-DHT and 3{beta}-ecdiol promote AR-dependent prostate cancer cell growth C_LIO_LIBoth are weaker AR agonists than testosterone by RNA-seq and qPCR C_LIO_LISupraphysiologic 5{beta}-DHT suppresses growth via AR-mediated senescence C_LIO_LIGrowth suppression extends to AR mutants W742C and H875Y C_LIO_LI5{beta}-DHT may be a lower-androgenicity testosterone surrogate for BAT C_LI

Chemotherapy resistance remains a critical barrier in treating osteosarcoma. Hypoxia-activated prodrugs (HAPs) target oxygen-deprived tumor regions that evade conventional chemotherapy. Here, we applied integrated spatial multimodal mass spectrometry imaging of metabolites (DESI-MSI, MALDI-MSI), targeted proteomics (IMC), and metallomics (LA-ICP-MSI) to naive and newly developed doxorubicin-resistant osteosarcoma spheroids treated with a novel HAP tirapazamine analogue, TPZ-A-X, and doxorubicin. Combination treatment selectively downregulated GLUT1 and suppressed pro-survival pAkt in doxorubicin-resistant spheroids whilst inducing comparable DNA damage ({gamma}H2AX) across both phenotypes. Metabolomics imaging identified ferroptosis pathway suppression in doxorubicin resistance, which combination treatment reversed, whilst simultaneously depleting glycolytic fuels. Integrative protein-metabolite correlation analysis uncovered functional couplings between glucose transport and CoA-dependent metabolism and spatially revealed anabolic signaling at spheroid peripheries. Combination treatment induced endogenous copper, zinc and magnesium depletion, independent of ATP/ADP collapse reflecting an adaptive survival remodeling of the metalloproteome. HAP/chemotherapy combinations exploit metabolic vulnerabilities via coordinated disruption of ferroptosis suppression, glycolytic dependence, and survival pathways underlying apoptotic resistance. These findings demonstrate a framework for informing mechanistic reasoning and combination strategy design in chemotherapy-resistant tumors.

IntroductionNectin-4 targeting antibody-drug conjugate (ADC) enfortumab vedotin (EV), in combination with pembrolizumab, is the first-line treatment for patients with locally advanced or metastatic urothelial carcinoma (UC). Optimal treatment strategies for patients who are non-responders or progress on EV with pembrolizumab remain an unmet clinical need. We sought to characterize ADC and immunotherapy (IO)-associated target expression profiles to identify candidate therapeutic vulnerabilities beyond EV. MethodsWe conducted a literature review to identify ADC and IO targets with approved or investigational relevance in UC. Unsupervised hierarchical clustering was used to identify clusters of target gene expression in RNA-seq data. Transcriptomic clustering analyses were performed in 434 patients from The Cancer Genome Atlas Bladder Urothelial Carcinoma cohort (TCGA-BLCA) and validated in an independent cohort of 478 patients from the Oncology Research Information Exchange Network (ORIEN) consortium. Proteomic interrogation of these targets was performed using mass spectrometry data from additional cohort of 116 patients. Differential gene expression analyses evaluated associations between target expression patterns, histologic variants, and consensus molecular subtypes of muscle-invasive bladder cancer (CMIBC). ResultsWe identified 13 ADC and 10 IO-associated targets with translational relevance in UC. Transcriptomic analyses revealed three reproducible clusters of overexpressed target genes across independent cohorts: 1) a luminal/epithelial-associated cluster enriched for VTCN1, SLITRK6, FGFR3, NECTIN4, TACSTD2, ERBB2, and ERBB3; 2) an immune target predominant cluster enriched for BTLA, LAG3, PDCD1, TIGIT, CTLA4, TNFRSF9, TNFRSF18, TNFRSF4; and 3) a basal/neuroendocrine-associated cluster characterized by CD274, F3, NT5E, EGFR, MET and DLL3. Similar clusters were largely conserved at the proteomic level. Adenocarcinomas overexpressed ERBB3 compared to neuroendocrine and squamous cell carcinomas. Pure squamous cell carcinomas overexpressed TACSTD2 compared to adenocarcinomas. In CMIBC subtypes, basal/squamous tumors expressed higher levels of CD274, EGFR, F3, LAG3, NT5E, and TNFRSF18, whereas luminal tumors demonstrated higher ERBB2 and ERBB3 expression. Neuroendocrine-like tumors showed higher DLL3 expression compared to all other subtypes. Tumors with low expression of NECTIN4, TACSTD2, and FGFR3 were enriched for alternative targets including DLL3, CD274, and CD276. Our findings provide a framework for hypothesis-driven therapeutic prioritization in advanced UC. Conclusions: UC is characterized by reproducible, biologically distinct patterns of ADC and IO target expressions. The degree of expression of NECTIN4 was positively associated with TACSTD2, FGFR3 and inversely associated with DLL3, CD276, and CD274, supporting alternative biologically informed treatment strategies besides EV . Histologic variants and molecular subtypes of UC also display distinct patterns of target expression. This study provides the first integrated transcriptomic framework linking ADC and IO target co-expression patterns for hypothesis-driven therapeutic prioritization. These findings provide a basis for rational ADC and immunotherapy development in advanced UC and support prospective proteomic validation in treatment stratified cohorts. Statement of Translational RelevanceEnfortumab vedotin plus pembrolizumab has redefined first-line therapy for advanced urothelial carcinoma, yet treatment selection following resistance or progression remains undefined. In this study, we integrate transcriptomic and proteomic analyses across independent cohorts to define reproducible patterns of antibody-drug conjugate (ADC) and immunotherapy target co-expression in urothelial carcinoma. We identify biologically distinct target-expression patterns that are associated with histologic and molecular subtypes and demonstrate coordinated and, in some cases, mutually exclusive relationships among therapeutically actionable targets. These findings have direct translational implications. First, they provide biologic rationale for rational sequencing and combination strategies based on co-expressed targets in NECTIN4-enriched tumors. Second, they identify alternative therapeutic vulnerabilities, including DLL3- and CD274-associated pathways, in tumors with low NECTIN4 expression, a population potentially enriched for resistance to EV-based therapy. Finally, this framework establishes a foundation for biomarker-driven clinical trials in urothelial carcinoma and supports the development of precision therapeutic approaches beyond current standards.