Journal of Experimental & Clinical Cancer Research

Immune checkpoint inhibitors targeting the PD-1/PD-L1 axis have shown great promise in treating bladder cancer and are now part of the standard treatment for advanced disease. However, many patients still fail to respond to treatment and at present many biomarkers are assessed but have yet shown only limited results. Therefore, with the advent of combination treatments and the increase of immune related adverse event, the search for reliable predictive biomarkers is paramount. Using a multiplexed enhanced FRET-FLIM based technique (QF-Pro) we quantified the interaction of PD-1/PD-L1, CTLA-4/CD80 and TIGIT/CD155 immune checkpoints in a pre-treatment TMA of 46 patients treated with atezolizumab. The association between higher PD-1/PD-L1 ICP interaction state and treatment efficacy was demonstrated in the male sample cohort, where it identified patients with better PFS. Conversely, patients exhibiting higher CTLA-4/CD80 engagement had a worse response to atezolizumab. Remarkably, the dual assessment of patients with high PD-1/PD-L1 and low CTLA-4/CD80 allowed to identify the best responders. These results indicate that the monitoring of patients immune profile in urothelial carcinoma might be critical in identifying patients who may benefit from combination therapy.

Circulating tumor cells (CTCs) are the potential seeds of distant metastases; however, little is known about how they survive in the bloodstream. Using a large cohort of colorectal cancer (CRC) patients, we found that the pseudokinase receptor PTK7 is highly expressed in primary tumors and metastatic lesions. Consistent with previous reports, high PTK7 expression is associated with reduced disease-free survival and increased metastatic dissemination. Surprisingly, PTK7 is absent from most CTCs and undergoes a cell-autonomous ONtumor/OFFCTC/ONmetastasis switch that can be recapitulated in a xenografted mouse model, in in vitro systems, and a fluidic platform. PTK7-negative cancer cells exhibit increased expression of YAP1-driven genes, senescence-like features, and enhanced resistance to hemodynamic stress following loss of cell-cell and cell-matrix adhesion. This adaptive phenotype depends on metalloproteases, notably ADAM17, whose cleavage activity remodels the CTCs surfaceome. Functionally, the PTK7 OFFCTC state confers enhanced metastatic potential in vivo, and can be pharmacologically suppressed using metalloprotease inhibitors. Collectively, our findings identify a reversible, cell-autonomous, protease-driven surfaceome remodeling program that enables metastatic adaptation during hematogenous dissemination. Highlights / statement of significanceBy investigating potential markers for circulating colorectal tumor cells with strong metastatic potential, we describe a reversible and cell-autonomous remodeling of the circulating tumor cell surfaceome in patients that confers resistance to anoikis and stress induced by entry into the bloodstream. One Sentence SummaryThe dynamic regulation of PTK7 serves as a surrogate marker for tumor cell plasticity, aggressiveness, survival in the bloodstream, and efficiency in forming metastases. Trial registrationCTC colon Cohort: registered on https://ClinicalTrials.gov identifier NCT03256084; date of registration 2017-07-17 B-Org cohort: registered on https://ClinicalTrials.gov NCT05384184; date of registration 2019-06-06 Ethics statement for animal experimentsStudies on animals were conducted in accordance with the current ethical standards of the European Community (Directive 2010/63/EU), the Ethics Committee for Animal Experimentation (CEEA#14) and the French Ministry of Higher Education and Research, which approved and authorized the entire procedure described in this paper (project number APAFIS #35294).

Neutrophils display marked functional plasticity in cancer; however, it remains poorly understood how soluble factors derived from hypoxic and irradiated head and neck squamous cell carcinoma (HNSCC) cells reprogram neutrophil phenotype and function. Here, we employed a well characterized and controlled in vitro model to examine how tumor-conditioned media (TCM) from HNSCC cell lines cultured under ambient (21% O2) or hypoxic (1% O2) conditions, with or without 6 Gy gamma irradiation, modulate human neutrophil phenotype, and functional and transcriptional responses. Initial analyses were performed using TCM from three different HNSCC cell lines, whereas subsequent mechanistic characterization focused on FaDu-derived TCM. We show that TCM prolongs neutrophil survival in a cell line-dependent manner. Among the tested cell lines, hypoxia-conditioned FaDu-derived TCM promoted immunomodulatory neutrophil state characterized by enhanced survival, selective priming of ROS production, and elevated TRAIL-R3/TRAIL-R2 ratio. Induction of classical activation markers (CD11b, CD62L) was not evident. Transcriptomic analysis revealed minimal effects of normoxic TCM. Hypoxia-conditioned TCM induced a pronounced transcriptional program enriched in hypoxia- and stress-associated pathways. In contrast, irradiation of tumor cells had a limited additional impact on neutrophil reprogramming. Together, these findings indicate hypoxia-conditioned tumor secretomes as important drivers of neutrophil functional adaptation in vitro, supporting a model in which soluble factors alone are sufficient to induce a persistent, immunomodulatory neutrophil phenotype. This work provides mechanistic insight into tumor-neutrophil crosstalk, highlighting hypoxia-driven signaling as a potential therapeutic target in radioresistant HNSCC and supporting a role for neutrophil reprogramming in this context.

BackgroundOvarian cancer (OvCa) ranks as the most lethal gynecological malignancy in women worldwide. This complex disease, which can develop independently of a womans age, is characterized by late diagnosis, pronounced tumor heterogeneity, and an immunosuppressive tumor microenvironment (TME). Incremental diagnostic tools that could better inform clinicians on potential therapy resistance or subsets of patients that could benefit from new drug modalities represent a critical unmet need to improve patient care and potentially the identification of new biomarkers. ObjectiveThis study aimed to establish a reconfigurable patient-derived OvCa-on-chip platform for longitudinal functional profiling of tumor cell death, immune activation, and patient-specific responses to TIL-mediated killing, PD-L1 blockade, and sequential chemo-immunotherapy. MethodsPatient-derived OvCa microtumors (PDM) were integrated with sequential integration of autologous tumor-infiltrating lymphocytes (TILs) into a perfusable microfluidic chip in the presence of different single and combination treatment regimens of chemotherapy and immune checkpoint inhibitors (ICIs). Treatment responses were assessed by longitudinal quantification of caspase-cleaved cytokeratin 18 (ccCK18) as marker of apoptotic epithelial tumor cell death, as well as cytokine/chemokine release in chip effluents, and multiplex flow cytometry-based characterization of autologous TIL subsets. ResultsThe perfusable OvCa-on-chip platform supported long-term culture of PDM while maintaining key structural and microenvironmental features of the primary tumor. Multidimensional analyses, including time-resolved assessment of tumor cell death, secretome profiling and correlative analysis of autologous TIL subsets revealed patient-specific tumor-immune response patterns and heterogenous sensitivity to TIL-mediated killing, PD-L1 blockade, and sequential chemo-immunotherapy. Correlation analyses identified treatment-dependent associations between specific TIL phenotypes and functional tumor cell killing. PD-1-expressing CD4 TIL subsets correlated with enhanced tumor cell killing, whereas terminally exhausted CD8PD-1Tcf1- TILs negatively correlated with durvalumab responses. In contrast, tumor-reactive CD8CD39 TILs were associated with improved responses under sequential chemo-immunotherapy conditions. ConclusionCollectively, this OvCa-on-chip system represents a complex in vitro model (CIVM) that combines 3D tumor tissue with autologous immune cells in a microfluidic platform. Resembling a physiologically relevant human preclinical platform, it allows for the time-resolved functional assessment of patient-specific responsiveness to OvCa therapies, with direct implications for personalized treatment stratification.

Endometrial cancer (EC), the most common gynecologic malignancy in the USA, has seen limited improvement in patient outcomes over recent decades, underscoring the need for relevant preclinical models. To address EC heterogeneity, we established an integrated platform of patient-derived xenografts (PDXs) and matched patient-derived primary cancer cells (PDCs) for disease modeling and systematic drug sensitivity testing. Fresh tumor specimens (n=103) were collected from EC patients to generate PDXs in immunodeficient mice and corresponding PDCs. Fifty-three PDX models were successfully established (52% engraftment rate), with higher success observed in high-grade, recurrent, metastatic tumors (70%), compared with their low-grade counterparts (56%). Histopathologic and immunohistochemical analyses confirmed that PDX tumors faithfully preserved morphology, hormone receptor status, and intertumoral heterogeneity across multiple passages. Using 13 PDC models, we performed an unbiased screening of 179 FDA-approved oncology drugs, revealing marked intertumoral variability in drug response. Almost all PDC models exhibited limited sensitivity to NCCN-recommended therapies, highlighting the need for alternative treatment strategies. In contrast, multiple FDA-approved agents including epigenetic modulators, dual PI3-kinase/HDAC inhibitors, topoisomerase II inhibitors, and proteasome inhibitors demonstrated potent antitumor activity. Importantly, a low-dose combination of the DNA methyltransferase inhibitor 5-azacytidine and the histone deacetylase inhibitor romidepsin significantly suppressed tumor growth across six independent PDX models. Together, these findings establish a comprehensive PDX and PDC platform as a robust translational resource. By capturing the histopathologic and molecular diversity of EC and identifying clinically actionable therapeutic advantages, including an epigenetic combination regimen, this study offers a translational resource for preclinical drug evaluation.

Abstract Background: High-grade serous ovarian cancer (HGSC) is characterized by extensive genomic heterogeneity and frequent alterations that promote replication stress (RS). Although RS has emerged as a promising therapeutic vulnerability, it remains unclear whether distinct RS-associated genomic alterations generate similar tumour states or drive unique biological programs and therapeutic dependencies. Methods: We developed and characterized a panel of syngeneic HGSC models representing recurrent RS-associated alterations, including overexpression of Ccne1, Brd4, Myc, Ndrg1, Pik3ca, and Brca1 heterozygosity, alongside previously established Pten/Nf1-deficient and Myc overexpressing models. Tumour fitness, transcriptomic programs, histopathology, extracellular matrix composition, immune organization, and therapeutic vulnerabilities were assessed using subcutaneous (s.c.) and intraperitoneal (i.p.) allografts, RNA sequencing (RNAseq), mass spectrometry (MS), cyclic-immunofluorescence (Cyc-IF), and preclinical therapeutic studies. Results: RS-associated genotypes exhibited marked differences in tumour fitness and generated distinct tumour ecosystem states despite sharing a common genetic background. Tumours harbouring BRCA1 heterozygosity displayed reduced tumour fitness, mesenchymal features, extracellular matrix remodelling, stromal expansion, and immune-excluded phenotypes. In contrast, tumours co-expressing Ccne1 and Brd4 exhibited the highest RS level together with strong activation of DNA damage response pathways and limited immune infiltration. Immune characterization identified immune-desert, immune-suppressed, and immune-excluded states across models, demonstrating substantial genotype-dependent immune heterogeneity. Elevated CD47 expression emerged as a defining feature of the Ccne1/Brd4 tumour state and was confirmed in human HGSC specimens with high CCNE1 and BRD4 protein expression. Therapeutic targeting of ATR and CD47 in intraperitoneal Ccne1/Brd4 allografts reduced tumour burden and induced histopathological responses compared with either monotherapy alone, supporting the translational relevance of this RS-high tumour state. Conclusions: Distinct RS-associated alterations do not converge on a common HGSC phenotype but instead generate diverse tumour ecosystem states with unique effects on tumour fitness, stromal remodelling, immune organization, and therapeutic vulnerabilities. These findings highlight the importance of considering the genetic origin of RS when developing therapeutic strategies and establish a framework for investigating genotype-specific vulnerabilities in HGSC.

Tumor infiltrating CD8+ T cells (TILs) progress to a state of terminal exhaustion (Ttex) which have impaired functionality and are nonrenewable. However their precursors (Tpex) are renewable and can generate efficient effector cells. We started from the observation that melanoma patients undergoing therapy with checkpoint inhibitors show increased survival when their T cells have low BCL11B mRNA. In line with this, ablation of Bcl11b in CD8+ TILs conferred a superior anti-tumor response in murine melanoma and ovarian cancer models. Bcl11b KO TILs failed to progress to the Ttex state and retained elevated stemness. Bcl11b exerted its role by repressing expression of essential transcription factors (TF) controlling stemness, and conversely by promoting expression of exhaustion-associated TFs and inhibitory receptor genes, through complex epigenetic control. In addition, Bcl11b KO CD8+ T cells showed increased Ag-specific cytolytic activity and elevated Gzmb and Prf1 proteins, but no increase in their mRNAs, however presented higher expression of genes with role in translation. Furthermore, CRISPR-CAS9-mediated deletion of BCL11B in human TILs from a patient with poor response to adoptive cell therapy with autologous TILs, improved their cytolytic activity and promoted expression of the stemness-associated TF TCF1, underlying its potential therapeutic use. HIGHLIGHTS- Adoptive transfer of Bcl11b KO CD8+ TILs surpasses WT in tumor burden reduction - Bcl11b ablation reprograms TILs and impairs the progression to Ttex state - Bcl11b KO CD8+ T cells have elevated cytotoxicity and kill only Ag-MHCI targets - BCL11B deletion in nonresponder ACT-TIL improves cytolytic activity and elevates TCF1 GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=64 SRC="FIGDIR/small/742578v1_ufig1.gif" ALT="Figure 1"> View larger version (33K): org.highwire.dtl.DTLVardef@10040d4org.highwire.dtl.DTLVardef@1a045caorg.highwire.dtl.DTLVardef@145f790org.highwire.dtl.DTLVardef@8012ab_HPS_FORMAT_FIGEXP M_FIG C_FIG

Abstract Background: Cytolytic activity (CYT), a widely used transcriptomic surrogate of anti-tumor immune cytotoxicity derived from GZMA (granzyme A) and PRF1 (Perforin 1) expression, is associated with clinical outcomes across cancers. MicroRNAs (miRNAs) are key post-transcriptional regulators of tumor immunity, yet their pan-cancer roles in modulating cytolytic activity remain incompletely understood. Objective: This study aimed to identify conserved miRNA regulators of tumor cytolytic activity and their downstream gene-mediated networks across diverse cancer types, while evaluating their clinical and therapeutic relevance. Methods: Matched miRNA and mRNA expression profiles from 9,288 primary tumors across 31 TCGA cancer types were analyzed. A multi-stage framework was applied: per-cancer Spearman correlations (|{rho}| >= 0.30, FDR < 0.05) identified recurrent CYT-associated miRNAs (at least 3 cancer types); these were integrated with TargetScan-predicted targets and subjected to pan-cancer and cross-cancer triple filtering (miRNA-gene and gene-CYT associations). All associations underwent tumor purity adjustment using Consensus Purity Estimate (CPE), with LUMP (Leukocytes Unmethylation for Purity) as sensitivity analysis. Candidates were further prioritized by random forest modeling with bootstrap stability, cancer-type-adjusted Cox regression, mediation analysis, immune cell deconvolution, k-means molecular subtyping, pathway enrichment, and DGIdb-based drug-target prioritization. Results: The analysis converged on 38 high-confidence miRNA-gene-CYT regulatory triplets involving 9 conserved miRNAs and 31 target genes after stringent purity adjustment and multi-layer validation. All nine miRNAs exhibited complete bootstrap stability. Mediation analysis confirmed significant gene-level mediation in 37 of 38 triplets (FDR < 0.01), with mediated proportions up to 94%. The final miRNA signature defined two distinct pan-cancer immune subtypes (immune-hot vs. immune-cold) with significantly different cytolytic activity and overall survival (OS) (HR = 0.754, FDR = 1.12 x 10^-4). The network was enriched for T-cell activation and lymphocyte differentiation pathways and highlighted multiple druggable targets, including CTLA4 and CD274 (PD-L1), nominating 124 candidate compounds. Conclusions: In conclusion, this tumor purity-adjusted pan-cancer study defines a compact, reproducible, and clinically relevant miRNA network that regulates cytolytic activity across diverse malignancies. By linking miRNA biology to immune subtyping and actionable therapeutic targets, the present work provides a valuable foundation for advancing precision immuno-oncology.

Background: Liquid biopsy-based monitoring of circulating tumor DNA (ctDNA) holds promises for real-time assessment of tumor burden and treatment response in precision oncology. However, mutation-based approaches alone show limited sensitivity, particularly in low-shedding tumors. We evaluated whether integrating epigenomic biomarkers (specifically LINE-1 retrotransposon (L1PA) hypomethylation and copy number variation (CNV)) with standard mutation-based ctDNA analysis could improve cancer detection and longitudinal monitoring in patients enrolled in the SHIVA02 precision oncology trial. Methods: We performed a retrospective analysis of 32 patients with advanced or metastatic solid tumors who received molecularly matched targeted therapies within the SHIVA02 trial (NCT03084757). Plasma samples were collected at baseline and longitudinally every two months and at progression. Multimodal ctDNA profiling was performed using the DRAGON targeted NGS panel covering SNVs, indels and focal CNVs in 571 genes and the DIAMOND assay profiling L1PA methylation and genome-wide CNV. A three-step classification algorithm integrating maximum variant allele frequency (MaxVAF), L1PA methylation-based cancer probability (MethPCancer), and genome-wide CNV scores was developed to maximize ctDNA detectability. Results: At baseline, mutation-based profiling detected ctDNA in 62.5% of patients. L1PA hypomethylation alone identified ctDNA in 78.1% of patients, including cases with undetectable mutations. The three-step integrative model increased overall detectability to 93.8%. Concordance analyses between tumor tissue and plasma revealed that 80.6% of mutations and 60% of CNVs identified in tumor biopsies were detectable in matched ctDNA. The three modalities showed limited pairwise correlation at baseline, supporting their complementarity. Longitudinal analysis demonstrated that changes in MaxVAF, MethPCancer, and L1PA CNV scores over time were informative on treatment response across tumor types, with ctDNA detected in 94.5% of samples collected at disease progression. In selected patients, ctDNA alterations preceded radiological progression by four months. Conclusions: Multimodal ctDNA profiling integrating mutation analysis, CNV profiling, and LINE-1 hypomethylation substantially improves ctDNA detection at baseline and during treatment in a pan-cancer precision oncology setting. These complementary genomic and epigenomic biomarkers provide a more comprehensive and dynamic assessment of tumor burden than single-modality approaches, supporting prospective validation in larger cohorts for integration into precision oncology workflows.

Chondrosarcoma is a hyper-vascularised, chemoresistant cartilage malignancy driven by VEGF-centred angiogenesis, and local adipose depots are increasingly recognised as paracrine drivers of tumour angiogenesis via adipokines and extracellular vesicles (EVs). The infrapatellar fat pad (IFP), an inflammatory adipose depot within the articular joint in direct cartilage contact, is a key local source of adipose-derived EVs, and thus a candidate driver of angiogenesis in chondrosarcoma. The aim of this study was to determine whether the IFP is a productive source of EVs, and whether IFP-derived EVs induce angiogenesis in articular chondrocytes. The IFP released significantly more EVs than subcutaneous fat (n = 8 per depot; p = 0.027). Treating primary human articular chondrocytes with IFP EVs for 24 h upregulated VEGFA (+1.6-fold, p = 0.036) and downregulated BMP4 (-2.4-fold, p = 0.011), engaging the VEGF/eNOS/ERK axis that drives chondrosarcoma angiogenesis. Re-analysis of a previously published phospho-kinase dataset from the same donor EVs, corroborated by a pooled donor-group analysis (n = 3), supported activation of eNOS, ERK1/2, PLC-{gamma}1 and HSP27. These findings identify the IFP as a dominant source of EVs within the articular joint, which can induce a pro-angiogenic, VEGF-axis switch in articular cartilage cells, supporting a signalling model relevant to chondrosarcoma angiogenesis.

Oral squamous cell carcinoma (OSCC), a highly aggressive subtype of head and neck cancer, remains a major clinical challenge with limited therapeutic options and poor survival outcomes. The Protein Inhibitor of Activated STAT1 (PIAS1), a SUMO E3 ligase involved in transcriptional regulation, DNA repair, and epithelial-mesenchymal transition (EMT), exhibits cancer type-specific roles, but its function in OSCC has not been well characterized. Here, we investigated the molecular and functional role of PIAS1 in OSCC progression and prognosis. All patient cohorts analysed here comprise HPV-negative disease. Analysis across multiple cohorts revealed that PIAS1 mRNA expression is significantly lower in tumor tissues than in normal oral cavity squamous epithelium, including in a cohort of 60 patient-matched tumor and normal pairs. Within the tumor compartment, protein abundance of PIAS1 correlated positively with patient survival. Functional assays using OSCC cell lines demonstrated that PIAS1 acts in a SUMO E3-dependent manner to suppress TGF{beta}-induced migration and invasion. Transcriptomic profiling of PIAS1-depleted cells revealed alterations in expression of genes with relevance in TGF{beta} signaling and pro-invasive cellular responses. Further analyses showed that 46 of these differentially altered hits intersected with The Cancer Genome Atlas (TCGA)-OSCC datasets, where four of these genes, including INHBA, associated with cell stemness-pathway. Spatial analysis of the mRNA abundance of INHBA within OSCC-derived surgical specimens showed increased abundance at the invasive front, and positively associated with aggressive tumor phenotypes, poor patients' outcomes, and resistance to immunotherapy. Single-cell RNA-seq analyses of INHBA revealed increased levels within tumor cells and cancer-associated fibroblasts (CAFs), suggesting potential tumor-intrinsic and extrinsic (tumor microenvironment) sources and hence actions. Collectively, our findings establish PIAS1 as a tumor suppressor in OSCC that restrains TGF{beta}-driven aggressive behaviour. Furthermore, we identify INHBA as a potential therapeutic target, among other genes characterized by spatially restricted, invasive tumor phenotypes.

Purpose: Whether host germline genetic variation determines tumor drug response remains underexplored. We evaluated whether EPAS1 (HIF-2) adaptive loss-of-function variants, enriched in high-altitude-adapted populations, predispose HCC to primary antiangiogenic TKI resistance through a HIF-2/STC2 signaling axis. Experimental Design: We integrated five independent data sources: the QHRCH-HCC retrospective cohort (n = 1,396), multi-ancestry iPSC-derived endothelial cell transcriptome data (GSE160906), TCGA pan-cancer data (LIHC, KIRC, LUAD, BRCA), GDSC2 pharmacogenomics (n = 951 cell lines; 11 antiangiogenic TKIs), and DepMap dependency data. The AESI_score integrated altitude, AFP-PIVKA-II inversion, platelet-altitude, and hemoglobin-altitude dimensions. Bayesian evidence integration employed the Effective Number of Independent Pieces of Evidence (ENIPE) method ({delta} = 0.504). Results: In QHRCH-HCC, altitude correlated positively with PIVKA-II ({rho} = +0.244, p = 0.0003) and with an altitude-adaptive genetic background score ({rho} = +0.517, p = 5.59x10-49). Under hypoxia, EPAS1 expression in high-altitude-adapted iPSC-ECs was reduced to 61.4% of controls (p = 0.0006), while STC2 remained relatively unaffected (89.2%, p = 0.180). In TCGA-LIHC, EPAS1[-&gt;]STC2 was weak ({rho} = 0.092) compared with HIF1A[-&gt;]STC2 ({rho} = 0.379, p = 2.21x10-14), establishing a negative control. Cross-cancer validation revealed strong EPAS1[-&gt;]STC2 in ccRCC ({rho} = 0.320, p = 3.47x10-14) but not in LUAD or BRCA. In GDSC2, EPAS1 correlated positively with IC50 of all 11 antiangiogenic TKIs (sign test p = 0.0005). Bayesian updating yielded posterior probability 0.970 (Log10BF = 1.99). Conclusions: EPAS1 LoF represents a germline determinant of TKI response, independent of tumor-acquired mutations. The AESI_score and HIF-2 inhibitor belzutifan constitute a predictive biomarker-therapeutic pair for genotype-stratified clinical validation. This hypothesis-generating study establishes a germline determinant framework for TKI resistance; definitive mechanistic validation will require prospective EPAS1 genotype-stratified cohorts (2023-ZJ-786).

CAR-T-cell-associated on-target off-tumor (OTOT) toxicity represents a major safety concern, as recognition of target antigens on healthy tissues can trigger severe and potentially life-threatening complications. Predicting OTOT toxicity remains a challenge because current preclinical models fail to capture the complexity of native human tissues. Here, we developed a human organotypic tissue platform that enables functional assessment of CAR-T-cell activity in intact human tissues across organ-specific and inflammatory contexts. Using a panel of clinically relevant CAR-T-cell products with known OTOT toxicities, we demonstrate that the platform faithfully recapitulates clinically observed tissue-specific toxicity profiles. CAR-T cells targeting EGFR, HER2, and mesothelin induced inflammatory and cytotoxic responses in healthy human lung tissue, whereas CD19 CAR-T cells remained inactive. We further show that OTOT toxicity cannot be reliably predicted from antigen abundance alone but instead results from the integration of multiple target-dependent determinants, including CAR affinity, inflammatory context, antigen accessibility, and effector-cell dose. The platform also enables quantitative assessment of inflammatory and cytotoxic responses and supports evaluation of pharmacological and CAR design-based strategies to mitigate toxicity. Together, this work establishes the first human organotypic platform for functional modeling of CAR-T-cell-associated OTOT toxicity, providing a clinically relevant framework for preclinical safety evaluation and the rational development of safer engineered cell therapies. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=167 SRC="FIGDIR/small/740527v1_ufig1.gif" ALT="Figure 1"> View larger version (38K): org.highwire.dtl.DTLVardef@2b47e2org.highwire.dtl.DTLVardef@17c7ce2org.highwire.dtl.DTLVardef@1eaf9feorg.highwire.dtl.DTLVardef@1c295bb_HPS_FORMAT_FIGEXP M_FIG C_FIG

Soft tissue sarcomas (STS) are a heterogeneous group of mesenchymal malignancies with generally poor prognosis, raising a continued interest in novel therapeutic targets. The TAM-family receptor tyrosine kinase AXL has been proposed as a therapeutic target across several cancer types, including STS. Here we revisit the clinical relevance of AXL in STS by combining in silico analyses with functional and transcriptomic characterisation of two representative AXL inhibitors, dubermatinib and bemcentinib, in the HT-1080 and SK-LMS-1 STS-derived cell models. STS ranked among the tumour types with the highest median AXL mRNA expression across The Cancer Genome Atlas, yet AXL expression was not associated with patient survival. Both dubermatinib and bemcentinib reduced cell viability and induced apoptosis but, unexpectedly, shRNA-mediated AXL knockdown failed to reproduce the antiproliferative effect of either inhibitor and did not modify cellular sensitivity to drugs treatment. Transcriptomic profiling after AXL genetic knockdown showed weak correlation with drug-induced transcriptional changes, with the large majority of drug-regulated genes being AXL-independent and largely specific to each cell line. Our data indicate that although dubermatinib and bemcentinib show clear antitumour activity in STS models, this activity is largely independent from AXL inhibition, suggesting the rationale for AXL-directed therapy may be reconsidered.

Pancreatic ductal adenocarcinoma (PDAC) is characterized by an immunosuppressive tumor microenvironment (TME) with pancreatic myofibroblasts (PMF) and macrophages being two prominent cell populations essentially impairing tumor responses to (immuno)therapies. L1 cell adhesion molecule (L1CAM) is upregulated in PDAC cells in primary and metastatic tissues and associated with tumor progression and therapy resistance. Using L1CAM as tumor-associated antigen, two bispecific antibodies (bsAB) targeting L1CAM and CD3 were developed in the IgG-(L)-ScFv format and their anti-tumorigenic activity was investigated in different preclinical PDAC models. In 2D models, both L1-bsAB exerted L1CAM-specific anti-PDAC cell activity when co-cultured with activated CD8+ T cells. Strong anti-PDAC cell effects along with elevated release of T cell effector molecules were also observed upon co-culture with peripheral blood mononuclear cells (PMBC) from healthy donors and PDAC patients. Of note, both L1-bsAB were also effective in 3D PDAC cell spheroids and neither impaired by PMF nor macrophages. Finally, application of L1-bsAB on organotypic tissue slice cultures from PDAC tissues comprising the entire complex TME also induced PDAC cell apoptosis and release of T cell effector molecules. Overall, our results highlight relevant anti-PDAC cell activity of L1-bsAB in immunosuppressive contexts supporting their potential as immunotherapeutic strategy for PDAC.

Lung adenocarcinoma is molecularly heterogeneous, and oxidative-stress programs can support either tumor restraint or tumor adaptation depending on cellular context. This study integrated public lung adenocarcinoma transcriptomic cohorts to identify oxidative-stress-associated expression features and evaluate their prognostic relevance. Expression profiles from The Cancer Genome Atlas, Genotype-Tissue Expression project, and GEO series GSE31210, GSE40791, and GSE30219 were analyzed. Differential expression, weighted gene co-expression network analysis, functional enrichment, univariable Cox regression, and least absolute shrinkage and selection operator Cox modeling were combined to derive a risk signature. Immune-cell enrichment, gene set enrichment analysis, gene set variation analysis, and pan-cancer analyses were used for biological characterization. A total of 1,305 genes differed between tumor and control samples, including 498 upregulated and 807 downregulated genes. Intersection of differentially expressed genes, the oxidative-stress-associated co-expression module, and the oxidative-stress gene set yielded 44 genes enriched in responses to reactive oxygen species and hydrogen peroxide, antioxidant and peroxidase activities, focal adhesion, Rap1 signaling, and PI3K-Akt signaling. A seven-gene signature comprising FBLN5, HBB, FYN, HGF, TFAP2A, PLIN5, and F2RL1 stratified the 523-sample training cohort and the 207-sample internal validation cohort into groups with different overall survival. Time-dependent areas under the receiver operating characteristic curve at 1, 3, and 5 years were 0.677, 0.622, and 0.649 in training and 0.613, 0.691, and 0.706 in internal validation. In the 85-case GSE30219 external cohort, corresponding values were 0.588, 0.661, and 0.631; survival separation followed the expected direction but did not reach statistical significance (log-rank P = 0.100). Seventeen immune-cell signatures differed between risk groups, while high-risk tumors were enriched for cell-cycle, DNA-replication, mismatch-repair, glycolytic, E2F, G2M-checkpoint, MYC-target, and mTORC1-related programs. The signature therefore captures reproducible oxidative-stress-associated transcriptional variation with moderate prognostic discrimination. Its clinical utility requires prospective evaluation, complete clinical adjustment, and experimental validation.

Triple negative breast cancer (TNBC) is an aggressive disease with limited therapeutic options. Conventional treatments include neoadjuvant chemo-immunotherapy followed by surgical resection and may include further adjuvant immunotherapy and/or radiotherapy of the tumor bed and lymph nodes. Nonetheless, TNBC patients with residual disease have rapid metastatic recurrence. While the roles of metabolic and mitochondrial adaptations in chemotherapeutic resistance have been the subject of many studies, their importance in the context of ionizing radiation (IR) therapy remains poorly understood. We established longitudinal in vitro models of post-IR human TNBC, characterized by cellular regression to a residual phenotypic state, then eventual cell repopulation. This was accompanied by plastic adoption of unique metabolic, proteomic, and morphologic features that largely reverted when cells regrew. Following IR, residual cells exhibited extensive mitochondrial rewiring, including elevated mitochondrial content, oxidative phosphorylation (oxphos) rates, cristae structures, and metabolite levels. Concomitantly, levels of the short protein isoform of the mitochondrial inner membrane protein optic atrophy 1 (OPA1) were significantly elevated in residual cells, and OPA1 knockout ablated mitochondrial adaptations induced by IR. OPA1 genetic or pharmacologic perturbations led to improved cellular responses to IR. Metabolomic and proteomic analyses of radio-residual cells uncovered a coordinated program of antioxidant and redox capacity elevation with mitochondrial metabolism, which was corroborated by analyses of external datasets. Together, these findings provide evidence that TNBC cells surviving radiotherapy adopt an OPA1-dependent program of mitochondrial reorganization that supports their survival and regrowth, thereby positioning OPA1 as a therapeutic dependency that could improve radiotherapy efficacy in TNBC.

Background: Cancer patients face a significantly elevated risk of severe COVID-19 outcomes. Although vaccination is a cornerstone of prevention, data on vaccination coverage and association with survival among Russian cancer patients remain scarce. We assessed COVID-19 vaccination coverage and its association with overall survival in a population-based cohort of cancer patients in Northwest Russia. Methods: This retrospective registry-based cohort study integrated data from the Population-Based Cancer Registry (PBCR) of the Arkhangelsk Region and the Nenets Autonomous Okrug, regional vaccination records, and an artificial intelligence (AI)-based analysis of chest computed tomography (CT) scans. The cohort consisted of 1,144 cancer patients who underwent CT between August 2020 and April 2021. Vaccination status was ascertained via data linkage. Overall survival (OS) was compared between vaccinated and unvaccinated patients using Kaplan-Meier analysis and multivariable Cox proportional hazards regression, adjusted for demographic, clinical, and AI-derived CT biomarkers. To mitigate immortal time bias, the primary analysis used a landmark approach restricted to patients alive on March1, 2021 (N=1,136). A sensitivity analysis used a November1, 2021 landmark (N=894). Vaccination status was defined as receipt of at least one dose before the landmark date. Results: Only 6.6% (n=76) of patients received at least one dose of a COVID-19 vaccine (Sputnik V or Sputnik Light). Vaccinated patients were more likely to have earlier-stage cancer and were less likely to be receiving active treatment. In the primary landmark analysis, vaccination was associated with a significantly higher 3-year OS (80.3% vs. 45.7%, p<0.001). In multivariable analysis, vaccination was independently associated with a 60% lower hazard of all-cause mortality (adjusted HR 0.40, 95% CI 0.25-0.64). AI-detected COVID-19 pneumonia on baseline CT was also an independent predictor of poorer survival (adjusted HR 1.32, 95% CI 1.09-1.59). In the sensitivity analysis (November1, 2021 landmark), the adjusted HR for vaccination was 0.56 (95% CI 0.34-0.92), showing a consistent but attenuated association. Conclusion: This study reveals critically low COVID-19 vaccination coverage among cancer patients in Northwest Russia. Nevertheless, vaccination was strongly associated with a substantial survival benefit, underscoring its importance as a potentially lifesaving intervention for this vulnerable population.

Circulating tumor cells (CTCs) are key drivers of distant metastasis, while platelets facilitate this process by protecting them from immune surveillance. However, the detection of CTCs exhibiting platelet markers and their communication with monocytes has not been thoroughly investigated. This study seeks to identify the intercellular communication of CTCs that have acquired platelet traits by integrating single-cell RNA-seq data of 377 CTCs and 2,634 white blood cells. Trajectory analysis identified a subpopulation of CTCs with enhanced platelet-related functions, including platelet aggregation and resistance to NK cell-mediated cytotoxicity, termed Platelet-Programmed CTCs. The Dampened Weighted Least Squares method was implemented to estimate the platelet-programmed tumor cell proportion in 1,102 bulk RNA-seq samples from primary breast cancer tumors. A strong inverse association was found between platelet-programmed tumor cell proportion and overall survival (Cox-PH p-value =0.00419, HR=6 per 10% increase in proportion, 95% CI:1.76-20.7). However, this association did not differ significantly between early- and late-stage patients. Cell-cell communication analyses and molecular docking revealed the CD40LG-ITGA5:ITGB1 pair as a potential immune checkpoint candidate for monocytes in cancer (Hex score=-656.83; TNF-TNFR reference complex=-515). However, further experimental and clinical validation is required to translate these findings. In conclusion, these findings deepen our understanding of the immune evasion mechanisms of CTCs by acquiring platelet characteristics. This immune checkpoint axis offers a novel avenue for further experimental validation and future intervention.

Background Ectonucleotide pyrophosphatase/phosphodiesterase 3 (ENPP3/CD203c) is largely studied as a marker of mast cells and basophils. By depleting extracellular ATP, it prevents excessive activation of mast cells and basophils, hence reducing inflammation and allergic reactions. Recent findings have also shown that Enpp3 can deplete cGAMP, another molecule involved in STING activation and IFN-mediated pro-inflammation. Little is still known regarding the role of Enpp3 in non-immune cells although a few reports have described its expression in healthy tissues and tumors. Methods In silico analysis were performed to investigate the expression levels and the prognostic value of Enpp3 in breast cancer, together with ovarian, prostate and colon carcinoma. ENPP3 expression was evaluated in formalin-fixed, paraffin-embedded tumor samples of breast cancer patients by immunohistochemistry, and in mouse mammary cancer cell lines by western blots. Cells were treated with EGFR ligands to stimulate the EGFR/HER2 axis. A mouse-derived mammary cancer cell line was engineered by CRISPR/Cas9 to introduce a GFP sequence under the control of the Enpp3 promoter. GFP-positive and -negative cells were sorted and analyzed by gene expression profiling to identify genes and pathways associated with Enpp3 expression. Finally, wild type and Enpp3 knockout cells were injected in the fat pad of Wsh mice, which do not have mast cells, to evaluate the growth of the tumors which were further analyzed by immunohistochemistry. Results We provide evidence that HER2-positive cells express higher levels of ENPP3 in samples of breast cancer patients. Moreover, in vitro models confirmed that HER2 expression and EGFR stimulation result in up-regulation of Enpp3. We identified pathways that can concur to Enpp3 expression and showed that in vivo the absence of Enpp3 promotes tumor growth and development of tumors with a marked epithelial-to-mesenchymal phenotype. Finally, in a small cohort of HER2-positive breast cancer patients, we found that ENPP3 expression correlates with increased relapse-free survival. Conclusions Despite its potential immunosuppressive role, our findings support the notion that ENPP3 expression is promoted by HER2 in breast cancer, and that it is endowed with a positive prognostic value.