Neoplasia

Dexamethasone is widely used to control cerebral edema and inflammation in glioblastoma, but its benefits are limited by systemic toxicities and adverse prognostic associations. We evaluated local administration of dexamethasone via convection-enhanced delivery (CED) to maximize intratumoral anti-inflammatory effects by increasing local corticosteroid exposure while minimizing systemic exposure. In two glioma mouse models, continuous intraparenchymal infusion of dexamethasone was well tolerated with no adverse effects. Pharmacokinetic analyses supported preferential intratumoral distribution and reduced systemic exposure with CED compared with systemic dosing. Single-nucleus RNA sequencing (snRNA-seq) and immunohistochemistry showed attenuation of glioma-associated inflammation with downregulation of reactive microglial/macrophage programs and reduced tumor-infiltrating myeloid cells with a morphology consistent with a less activated state. Experiments in human induced pluripotent stem cell (iPSC)-derived microglia confirmed that dexamethasone directly suppresses inflammatory gene expression, indicating a conserved mechanism across species. This inflammatory suppression was recapitulated in both immortalized microglial (HMC3) and macrophage (THP1) cell lines. These findings suggest that localized dexamethasone delivered by CED reprograms the glioma immune microenvironment and achieves control of inflammation without the systemic adverse effects associated with standard systemic dexamethasone therapy. This clinically translatable strategy may improve symptom management and provide a platform for integrating local immunomodulation with future glioblastoma therapies.

BackgroundPatient-derived tumor organoids are widely used in cancer research, yet the biological impact of tissue processing during model generation remains unclear. Fragment-based and dissociation-based approaches are commonly assumed to trade fidelity for uniformity, but their molecular consequences remain incompletely defined. MethodsWe performed a proteome-wide comparison of fragment-based (CUT) and dissociation-based (DIS) glioblastoma organoid protocols using quantitative mass spectrometry. Organoids from multiple patient tumors were cultured under growth factor-free or growth factor-supplemented conditions and compared with matched primary tissue. ResultsBoth protocols produced technically robust glioblastoma organoids when maintained in their native media. However, CUT organoids matched the reproducibility of DIS cultures while preserving a broader extracellular matrix repertoire and networks linked to collagen assembly, vascular support, and cell-matrix signaling. DIS cultures were biased toward exogenous basement membrane components and proliferative, growth factor-responsive states. Across tumors, CUT organoids consistently showed greater proteomic similarity to matched primary tissue, retaining neural, glial, stromal, and extracellular features largely absent from DIS models. ConclusionsFragment-based glioblastoma organoids can be both reproducible and biologically faithful. Tissue dissociation acts as a major perturbation that reshapes extracellular matrix organization, cellular states, and tumor identity, making protocol choice a critical determinant of model fidelity and translational relevance.

Background and AimsThe tumor microenvironment in colorectal cancer (CRC) is richly innervated, yet the contribution of the enteric nervous system (ENS) to CRC biology remains poorly defined. ENS neurons express proenkephalin (PENK), which can be processed by proprotein convertase 1/3 (PCSK1) to generate Methionine-enkephalin (M-ENK), a bioactive peptide with growth-regulatory potential. We hypothesized that an ENS-derived PCSK1-M-ENK axis restrains CRC proliferation through opioid growth factor receptor (OGFr) signaling and is modulated by stress-associated glucocorticoid receptor (GR) signaling and GLP1 receptor (GLP1R) activity. MethodsPublicly available human CRC single-cell RNA-sequencing datasets were analyzed for OGFr expression. PCSK1 and M-ENK expression in murine ENS and tumor-associated tissue was assessed by immunofluorescence. Functional studies were performed using murine CRC organoids, and primary murine ENS neurons in mono- and co-culture. CRC proliferation was quantified by EdU incorporation following treatment with recombinant M-ENK, recombinant PCSK1, OGFr synthetic ligand naloxone, or PCSK1 inhibitors. Effects of dexamethasone and liraglutide on PCSK1 expression in ENS-containing murine tissue were evaluated. ResultsOGFr was enriched in CRC cells and positively associated with KRAS gene expression. A subset of adult murine colonic myenteric neurons expressed PCSK1 and M-ENK. M-ENK dose-dependently suppressed proliferation of CRC organoid cells. ENS neurons also suppressed CRC proliferation in a PCSK1-dependent manner. Dexamethasone reduced, whereas liraglutide increased, PCSK1 expression. ConclusionsThese findings define a previously unrecognized ENS-derived neuro-oncologic pathway that is associated with reduced CRC cell proliferation and identify the GR/GLP1R-PCSK1-M-ENK axis as a potentially actionable therapeutic node. SummaryThis study identifies a neuronal PCSK1 - M-ENK pathway in the ENS that directly suppresses colorectal cancer growth through local OGFr activation, revealing a previously unrecognized neuropeptidergic mechanism of tumor control within the intestinal microenvironment.

Drug resistance to the androgen receptor (AR) antagonist is a critical obstacle in the clinic for advanced prostate cancers. Especially, AR antagonist treatment-induced neuroendocrine progression represents a lethal and therapy-resistant subtype. Although transcriptional and epigenetic lineage plasticity have been extensively implicated in treatment-induced neuroendocrine progression, the contribution of metabolic adaptation remains incompletely understood. Here, we identified a previously unrecognized metabolic reprogramming mechanism induced by AR antagonists in castration-resistant prostate cancer (CRPC) models. AR antagonist treatment markedly enhanced glycolytic activity and induced glyceraldehyde-3-phosphate dehydrogenase (GAPDH) expression. Genetic depletion of GAPDH suppressed AR antagonist-induced glycolytic activation, altered transcriptomic and metabolic programs, reduced neuroendocrine-associated marker expression, and inhibited xenograft tumor growth. Mechanistically, GAPDH promoter pulldown coupled with mass spectrometry, siRNA screening, and chromatin immunoprecipitation assays identified myeloid zinc finger-1 (MZF1) as a key transcription factor for Enzalutamide-induced GAPDH gene expression. Pharmacological inhibition of GAPDH using koningic acid (KA) or penta-O-galloyl-{beta}-D-glucopyranose (PGG) significantly suppressed tumor growth and attenuated neuroendocrine-associated molecular programs in CRPC cell-derived xenograft and patient-derived t-NEPC xenograft models. Collectively, our findings identify an AR antagonist-induced MZF1-GAPDH signaling axis that promotes glycolytic activation and neuroendocrine-associated metabolic adaptation during treatment resistance. These results support targeting GAPDH-dependent metabolic reprogramming as a potential therapeutic strategy for treatment-resistant prostate cancer. Graphic abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=112 SRC="FIGDIR/small/729867v1_ufig1.gif" ALT="Figure 1"> View larger version (58K): org.highwire.dtl.DTLVardef@180c5feorg.highwire.dtl.DTLVardef@146c015org.highwire.dtl.DTLVardef@1ece2f4org.highwire.dtl.DTLVardef@12819c0_HPS_FORMAT_FIGEXP M_FIG C_FIG

BackgroundGlioblastoma (GBM) is a sex-biased disease characterized by higher incidence and poorer survival in males. These sex differences are primarily driven by metabolic and immune signatures, with iron metabolism playing a major role. While iron is essential for tumor cell proliferation, it is also critical for T cell recruitment and function within the tumor microenvironment (TME). Clinical data indicates that iron deficiency impacts GBM survival in a sex-biased manner; however, the underlying mechanisms remain unexplored. MethodsWe employed a FTH1 heterozygous knockdown mouse model to induce tumor iron deficiency in GBM-bearing mice. TME dynamics were interrogated using flow cytometry and spatial transcriptomics (10X Xenium) to analyze immune infiltration, localization, and ligand-receptor signaling between GBM and immune cells. ResultsFTH1 knockdown resulted in iron deficiency in the GBM TME. Iron deficiency altered the TME dynamics in a sex biased manner. FTH1 knockdown in females caused an anti-inflammatory, cytokine deficient TME which failed to recruit CD4 and CD8 T cells. In males, FTH1 knockdown caused a proinflammatory environment by activating the innate immune response. Additionally, FTH1 knockdown increased the density of TAMs in the immediate surrounding of GBM cells in a sex biased manner. ConclusionThese results demonstrate that tumor iron plays a sex-biased role in immune infiltration and anti-tumor immunity.

BackgroundSurvivin is a mitotic regulator frequently overexpressed in human cancers and an attractive therapeutic target. However, how Survivin inhibition influences tumor immune regulation remains incompletely understood. This study aimed to investigate whether Survivin inhibition modulates antitumor immunity and to elucidate the underlying mechanisms. MethodsProgrammed death-ligand 1 (PD-L1) expression was evaluated in multiple tumor cell lines following pharmacological or genetic inhibition of Survivin. Mechanistic studies included RNA sequencing, immunoblotting, flow cytometry, cGAS knockdown, and NF-{kappa}B inhibition. Immune profiling was performed using CD8 T-cell cytotoxicity assays, mass cytometry, flow cytometry, immunofluorescence and single-cell RNA sequencing. Clinical relevance was assessed using patient tumor specimens and public immunotherapy cohorts. ResultsSurvivin inhibition, either by YM155 treatment or genetic depletion, increased PD-L1 expression at both mRNA and protein levels in tumor cells. Mechanistically, Survivin inhibition stabilized cyclic GMP - AMP synthase (cGAS) by reducing its ubiquitination and activated NF-{kappa}B signaling, thereby promoting transcriptional upregulation of PD-L1. Functionally, the induced PD-L1 enhanced PD-1 engagement and suppressed CD8 T-cell cytotoxicity, promoting immune evasion. In immunocompetent ovarian cancer models, pharmacological inhibition of Survivin increased PD-L1 expression in tumor and immune compartments and attenuated cytotoxic immune activity. PD-L1 blockade restored antitumor immunity and significantly enhanced the therapeutic efficacy of Survivin inhibition. In addition, analyses of patient samples and public single-cell datasets revealed an inverse association between Survivin and PD-L1 expression, and high Survivin expression was associated with reduced benefit from PD-1/PD-L1 blockade. ConclusionsThese findings identify a Survivin-cGAS-PD-L1 axis linking mitotic stress to immune suppression and provide a mechanistic rationale for combining Survivin-targeted therapy with immune checkpoint blockade.

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

BackgroundCytokines are immunomodulatory proteins that play central roles in regulating immune responses and represent attractive targets for cancer therapy. However, as single agents, cytokines have shown limited clinical benefit due to systemic toxicities and a short in vivo half-life. Our group has focused on engineering fusion cytokines (fusokines) that couple two cytokines into a single biologic to reprogram immune cell responses by enforcing non-canonical receptor engagement and signaling. A chimeric IL-6/IL-1{beta} fusokine was engineered to test the hypothesis that enforced co-engagement of IL-6 and IL-1{beta} signaling pathways would confer a gain-of-function phenotype in T cells and promote robust anti-tumor immunity. Here, we describe the immunomodulatory properties of IL6/1 fusokine and a method to deliver this fusokine to produce inhibition of ovarian tumor growth in a pre-clinical mouse model. MethodsLentiviral vectors encoding murine or human IL6/1 were designed using Vector Builder and expressed in either HEK293, CHO or ID8-F3 (p53-/-) cells depending on the downstream experiment to be conducted. IL6/1 expression was validated by ELISA and flow cytometry. Effects of human IL6/1 (hIL6/1) on T cell function (proliferation, memory phenotype, activation induced apoptosis) were monitored by flow cytometry. For in vivo studies, ID8-F3 murine ovarian cancer cells expressing mouse IL6/1 (mIL6/1) were administered intraperitoneally (I.P.) as a cell-based therapy to C57BL/6 female mice bearing established ID8-F3 luciferase tumors. Tumor progression was monitored by bioluminescence (BLI) imaging, and overall survival was evaluated. ResultshIL6/1 significantly enhanced T cell survival and selectively promoted activation and expansion of CD45RO memory T cells. mIL6/1 expressing ID8-F3 cells (ID8IL6/1) demonstrated stable transduction and sustained cytokine secretion. In vivo, ID8IL6/1 cell therapy significantly reduced tumor growth and improved overall survival compared to control groups, with 2 of 8 mice achieving complete tumor clearance. ConclusionThese findings indicate that IL6/1 fusokine enhances T cell survival and proliferation while promoting memory responses. Engineered cancer cells (ID8-F3) expressing mIL6/1 fusokine induced a strong anti-tumor response when delivered as a therapeutic vaccine in ovarian cancer mouse model. What is already known on this topicO_LIFusokines are a class of bifunctional proteins designed to achieve synergistic immune modulation. Previous studies in our lab have shown fusokine exhibit gain-of-function immunomodulating activity. Individually, IL-6 and IL-1{beta} are recognized for their roles in promoting T-cell proliferation and effector function. However, the potential for a fused IL-6/1 fusokine to reprogram the immune system and elicit a superior anti-tumor response in vivo in ovarian cancer model is not yet studied. C_LI What this study addsO_LIThis study develops a novel fusion cytokine (fusokine), combining IL-6 and IL-1{beta}, and demonstrate robust activation of T cells. In a preclinical ovarian cancer model, engineered cancer cells expressing IL6/1 used as a therapeutic vaccine showed significant tumor reduction and improved overall survival. C_LI How this study might affect research, practice or policyO_LIThis study demonstrates that in comparison to individual cytokines, fusokines have greater potential to activate T cell function and when delivered as a cell therapy, achieve clear therapeutic efficacy in an ovarian cancer model. Further translational and clinical studies may enable the development of novel and more effective fusokine cell therapy approaches for patients with ovarian cancer. C_LI

Glioblastoma (GBM) is the most aggressive primary brain tumor in adults. Cognitive impairment is a common sequela in glioblastoma survivors, yet the underlying mechanisms remain poorly understood. Extracellular vesicles (EVs) derived from glioblastoma are established mediators of intercellular signaling within the tumor microenvironment. Here, we investigated whether GBM-derived EVs released after radiation treatment (RT-EVs) regulate cognitive function. Treatment with RT-EVs was associated with cognitive deficits and neuroinflammatory responses in vivo. In vitro, RT-EVs activated the NF{kappa}B pathway and induced the release of neurotoxic H2O2. Importantly, NF{kappa}B p50 knockdown abolished the H2O2 release previously triggered by RT-EVs, demonstrating mechanistic dependence on NF{kappa}B signaling. Collectively, these findings identify GBM-derived RT-EVs as critical mediators of cognitive impairment through NF{kappa}B-dependent redox imbalance. EV-driven redox dysregulation may therefore represent a therapeutic target to mitigate GBM-associated cognitive dysfunction. Highlights- Radiation induces the release of glioblastoma-derived EVs that are biologically different from those released under non-irradiated conditions. - EVs released from glioblastoma after radiation are sufficient to impair cognition - EVs from irradiated glioblastoma can activate microglia via NF{kappa}B and induce production of neurotoxic H2O2 Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=52 SRC="FIGDIR/small/730969v1_ufig1.gif" ALT="Figure 1"> View larger version (11K): org.highwire.dtl.DTLVardef@8dc45borg.highwire.dtl.DTLVardef@156547forg.highwire.dtl.DTLVardef@c593e0org.highwire.dtl.DTLVardef@16f68f5_HPS_FORMAT_FIGEXP M_FIG C_FIG

Glioblastoma (GBM) is the most aggressive primary brain malignancy, characterized by hypoxia-driven proliferation, therapeutic resistance, and poor prognosis. While hypoxia-induced transcriptional changes are well documented, the temporal regulation of cell cycle genes under sustained hypoxia remains unclear. This study profiled transcriptomic alterations in U87MG cells cultured under normoxia and graded hypoxia for one to three days. Differentially expressed genes (DEGs) were identified and analyzed using STRING, Cytoscape, MCODE, and CytoHubba to construct protein-protein interaction (PPI) networks and extract hub genes. Functional enrichment was assessed through DAVID, ClueGO, and KEGG, while prognostic relevance was evaluated using GlioVis and ONCOMINE datasets. qRT-PCR validated expression of selected hub genes. A total of 294 DEGs were identified, forming two main functional modules enriched in cell cycle regulation and chemokine signaling pathways. Eighteen hub genes (KIF20A, CCNB1, AURKA, EGR1, CDCA3, CENPF, CDCA2, ASPM, KIF11, CCL2, CCNA2, DLGAP5, RACGAP1, TPX2, PTGS2, CTGF, and KIFC1) were significantly associated with mitotic processes and GBM progression. Survival analysis demonstrated that 17 of these genes correlated with poor overall survival (p < 0.05). qRT-PCR confirmed that hub gene expression peaked during early hypoxia and declined with prolonged exposure, indicating dynamic regulatory adaptation. These findings identify key hypoxia-responsive genes governing cell cycle progression and highlight their prognostic and therapeutic potential in glioblastoma.

BackgroundGlioblastoma is an aggressive and incurable brain tumor. Clinical trials of immune checkpoint inhibitors showed no clinical benefit in glioblastoma when given after surgery. However, a clinical trial in which PD1 inhibition was given prior to second surgery did show pharmacodynamic evidence for activity. This suggests the possibility that immune checkpoint inhibitors may be more effective in a setting where large tumors are present. Here we have studied immune responses to large tumors in an autochthonous mouse model of glioblastoma. MethodsGlioblastoma was induced by transfection with oncogenic plasmids injected directly into the lateral ventricle of neonatal mice. Immune responses were assessed using a combination of spectral flow cytometry and immunohistochemistry. ResultsThere was a marked immune response to large tumors, with significant increases in CD4 T cells and dendritic cells. T cell changes occurred primarily at leptomeningeal/perivascular border sites. A large proportion of CD4 T cells expressed PD1 and half of these were regulatory T cells. NK cells were also increased in mice with large tumors, but were predominantly in immature states. The mouse model accurately recapitulates the formation of palisading necroses. These contain apoptotic cells and avidly recruit myeloid cells that are induced to express large amounts of TGF{beta}. ConclusionsLarge glioblastoma tumors generate a border site population of PD1 positive T cells that may explain the pharmacodynamic response in neoadjuvant trials, and a palisading necrosis-driven immunosuppressive mechanism that may explain why responses are insufficient to provide a significant clinical benefit. KEY POINTSThe SB mouse model accurately recapitulates immune features of human glioblastoma Large tumors induce a significant border site immune response Palisading necroses in large tumors counter this with a strong immunosuppressive response IMPORTANCE OF STUDYImmune checkpoint inhibitors have not shown efficacy in glioblastoma when used post-surgery, but do show pharmacodynamic activity when used in patients prior to second surgery (i.e. neoadjuvant). This suggest the possibility that immune checkpoint inhibition is more effective when large tumors are present. Using a clinically-relevant autochthonous mouse model, we show here that large tumors induce an immune response that is evident in leptomeningeal border sites. Large tumors in this mouse model also generate palisading necroses, a well-known diagnostic feature in glioblastoma tumors. These palisading necroses generate large amounts of TGF{beta}, providing a mechanism by which large tumors can suppress border site immune responses. This further supports the concept that palisading necroses are drivers of glioblastoma malignancy and suggests novel strategies to enhance responses to immune checkpoint inhibition in this cancer.

BackgroundMesothelioma (Me) is an aggressive cancer with limited response to conventional therapies. The tumors harsh microenvironment contributes to immune escape and therapy resistance and the effects of ICIs on Me are still unclear. Adenosine, an immunosuppressive molecule produced from AMP by the enzyme CD73, accumulates in hypoxic tumor areas. Elevated CD73 and adenosine receptor A2B (A2Br) levels on Me cells are linked to worse patient outcomes, indicating their important role in disease progression and potential as targets for treatment. AimThis study characterizes the Me-ME (micro environment) and evaluates the efficacy of TT-4 (A2B inibitor) and AB680 (CD73 inibitor), alone or with aPD-1, using 3D models in vitro and in vivo. MethodsCD73 and A2B receptor levels were quantified in tumor and normal samples using qRT-PCR and IHC. Cells lines were treated with CoCl2 to mimic hypoxia, then CD73, A2Br and related markers were analyzed. MSTO-211H and REN cells were silenced for CD73, grown as spheroids and adenosine release was measured. Co-culture spheroids of MSTO-211H and Jurkat cells were treated with AMP and CD73 inhibitor, then analyzed for viability and immune markers. An orthotopic Me model was established by injecting AB1-B/c-LUC cells and monitored by in vivo imaging. Proteomic analysis of spheroids was conducted to identify proteins and pathways involved. ResultsHypoxia boosts CD73 and A2Br expression in Me cells, leading to adenosine production via CD73. In 3D co-cultures, AB680 lowered Me cell viability and enhanced activation of Jurkat T cells. In mice, combining aPD-1 therapy with A2Br or CD73 inhibitors strongly reduced tumor growth. Proteomics identified 93 proteins influenced by adenosine signaling through A2B. ConclusionTargeting the adenosine pathway alongside PD-1 blockade offers a promising new immunotherapy strategy for Me.

In pediatric brain tumors medulloblastoma (MB) and diffuse midline glioma (DMG), tumor-associated myeloid cells (TAMs) support malignant progression by secreting paracrine growth factors and suppressing local immune function. We studied the potential for reversing this cancer-supportive phenotype by stimulating TAM pathogen receptors using ResiPOx, a brain-permeant, polyoxazoline nanoparticle formulation of the TLR7/8 agonist resiquimod. ResiPOx showed blood-brain barrier penetration and anti-tumor efficacy, extending progression-free survival (PFS) in mice with MB and DMG. Integrated cellular and molecular analysis including scRNA-seq showed that ResiPOx expanded TAM populations and reprogrammed TAMs toward anti-tumoral states, blocking paracrine IGF1 signaling and inducing local cytokine signaling and phagocytosis of tumor cells. In rhesus macaques, systemic ResiPOx was well tolerated and induced brain transcriptional patterns that resembled ResiPOx responses in DMG and MB mouse models, indicating effects in non-human primates that highlight translational potential. Our data show that ResiPOx reshapes the brain tumor microenvironment to inhibit tumor growth. As a systemically administered, brain penetrant immunomodulator, ResiPOx is able to reach multifocal and unresectable brain tumors, including MB and DMG.

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.

Chromophobe renal cell carcinoma (ChRCC) accounts for 5% of all renal cancer cases. Despite its generally indolent behavior and low mutational burden, there is no targeted therapy for metastatic ChRCC. Profilin-1 (Pfn1), a cytoskeletal regulator of actin and tubulin dynamics, has emerged as a potential oncogenic driver in several cancers including RCC, but its role in ChRCC, remains undefined. We observed elevated Pfn1 expression in stage IV ChRCC patients, implicating Pfn1 in advanced disease progression. To investigate this, we manipulated Pfn1 expressions in two ChRCC cell lines UOK276 and RCJ41M. Pfn1 knockdown (KD) significantly reduced proliferation, invasion, and colony formation, whereas Pfn1 overexpression (OE) in UOK276 enhanced ChRCC aggressive phenotypes. Pharmacological inhibition of Pfn1 significantly suppressed proliferation and clonogenic growth in both cell lines. Additionally, Pfn1 KD increased intracellular ROS accumulation, while overexpressed reduced ROS levels, linking cytoskeletal regulation to oxidative stress control. Together, these findings position Pfn1 as a critical mediator of ChRCC progression, linking cytoskeletal remodeling to aggressive tumor behavior. This work highlights Pfn1 as a potential therapeutic target and establishes a framework for cytoskeletal-focused strategies in advanced ChRCC.