Lymph node (LN) function requires the organization of cells into higher-order spatial units. However, the principles governing LN architecture in health and disease remain poorly understood. Here, we used single-cell and spatial mapping to investigate the mechanisms directing immune cell organization in human LNs and its disruption in architecturally distinct lymphoma entities: indolent follicular lymphoma (FL) and aggressive diffuse large B cell lymphoma (DLBCL). Our data substantiate the central role of LN-resident stromal cells in chemokine-driven lymphocyte zonation and reveal an inflammatory feedback loop fueled by tumor-reactive T cells that triggers stromal remodeling, progressive loss of homeostatic chemokine gradients, and tissue disorganization from a non-malignant state to FL and DLBCL. Loss of homeostatic chemokines was associated with adverse patient survival, identifying the underlying architectural rearrangement as a key event during lymphomagenesis. Collectively, our results highlight the principles of LN organization and suggest how lymphoma-induced microenvironmental reprogramming drives the loss of tissue organization.

TET2-CH colorectal and melanoma cancer patients show enhanced immune infiltration

T cell-mediated immune surveillance is critical for cancer control, yet its role in bone marrow malignancies remains poorly understood. Here, we integrate TCR profiling, HLA immunopeptidomics, and functional screening to characterize tumor-reactive T cells in the bone marrow of patients with multiple myeloma (MM) and acute myeloid leukemia (AML). These cells are transcriptionally defined by a conserved effector program distinct from the exhausted phenotype of tumor-reactive T cells in solid cancers. Immunopeptidomic profiling reveals a partially shared antigen landscape enriched for noncanonical peptides driving convergent TCR responses. We develop TFiT (tumor-reactive features in T cells), a transcriptional classifier that identifies these cells and stratifies immunotherapy, but not chemotherapy, response across independent MM and AML cohorts, supporting its specificity for T cell-mediated tumor control. These findings reveal a latent but activatable anti-tumor T cell compartment in bone marrow malignancies and provide a framework for engaging endogenous immunity in MM and AML.

Metabolic reprogramming is a hallmark of cancer, and the field has predominantly focused on investigating metabolic alterations in tumour cells. However, the relevance, mechanism and consequences of metabolic adaptations in stromal cells remain understudied. Here, we identify aspartoacylase (ASPA) as a metabolic enzyme consistently repressed in tumour stroma and cancer-associated fibroblasts (CAFs). Importantly, we report a reciprocal crosstalk between ASPA and Transforming Growth Factor Beta (TGFβ) signalling that influences fibroblast behaviour. TGFβ suppresses ASPA expression in fibroblasts, whereas ASPA restrains TGFβ-dependent myofibroblast conversion, extracelullar cell matrix (ECM) remodelling, angiogenesis and pro-tumoral macrophage phenotypes. Analyses of human specimens revealed a strong negative prognostic value for ASPA in different tumour types, associated with TGFβ signalling levels and the generation of aggressive pro-tumoral responses. Our findings unveil ASPA expression in fibroblasts as a gatekeeper of TGFβ responses and activation in cancer progression.

Peripheral nerves are emerging regulators of the tumor microenvironment, but how sensory innervation shapes breast cancer immunity remains poorly defined. Here we show that triple-negative breast cancers (TNBCs) co-opt nociceptor neurons to suppress antitumor immunity and promote disease progression. Across orthotopic TNBC models, we found that primary tumors and tumor-draining lymph nodes were densely innervated by CGRP⁺ sensory fibers. Tumor-derived cues directly activated dorsal root ganglion neurons, increased calcium responsiveness, induced Ngfr and Atf3, and triggered release of CGRP and substance P. Mechanistically, a tumor-derived proNGF-NGFR axis reprogrammed nociceptors and promoted neuropeptide secretion. Soluble mediators from activated nociceptors suppressed CD8⁺ T cell-mediated tumor-cell killing, whereas sensory-neuron silencing or ablation curtailed tumor growth and remodeled the immune microenvironment toward dendritic-cell activation, myeloid reprogramming, and enhanced CD8⁺ T cell and NK-cell effector states. Subset-specific analysis revealed nonredundant sensory control of immune states, with MrgD⁺ neurons selectively shaping macrophage-centered programs. Finally, blockade of CGRP signaling through RAMP1 reduced tumor growth and markedly enhanced PD-1 blockade, nearly eliminating primary tumor burden and lung metastasis in vivo. T cell-specific Ramp1 deletion similarly restrained tumor growth, and RAMP1⁺ CD8⁺ T cells in human TNBC displayed an exhaustion-associated phenotype. Together, these findings define a tumor-promoting proNGF-nociceptor-CGRP-RAMP1 axis and identify neuroimmune signaling as a therapeutically actionable vulnerability in TNBC.

Ferroptosis, a distinct form of cell death driven by lipid peroxidation, holds considerable potential as a therapeutic strategy for cancer. Its unique mechanisms, centered on the disruption of cellular systems that protect against phospholipid peroxidation, distinguish ferroptosis from apoptosis and other well-characterized forms of cell death. This creates a novel therapeutic opportunity; however, it also presents challenges, as non-cancerous cells likewise depend to some extent on ferroptosis-regulating pathways. Consequently, extensive research efforts have focused on identifying suitable molecular targets, developing targeted drug delivery strategies, defining cancer types that are particularly dependent on ferroptosis-regulatory components, and establishing effective patient stratification approaches. Furthermore, exploring combination therapies may further enhance therapeutic efficacy through additive or synergistic effects. This review highlights the potential synergistic effects of combining ferroptosis induction with conventional cancer therapies, including chemotherapy, immunotherapy, and radiation therapy. Preclinical studies indicate that promoting ferroptosis may help overcome drug resistance, a major barrier that often limits the efficacy of existing treatments. Nevertheless, the successful development of ferroptosis-based therapies will require overcoming several challenges through innovative therapeutic strategies.

CH mutational profile of NCT02644359 patients

Abstract Profiling and targeting pancreatic cancer innervating neurons. The peripheral nervous system (PNS) orchestrates organ function in health and disease. Many cancers, including pancreatic ductal adenocarcinoma (PDAC), are infiltrated by PNS neurons that contribute to the complexity of the tumor microenvironment (TME). However, the cell bodies of these neurons reside in distant PNS ganglia, causing cancer- or organ-innervating neurons to be largely absent from current tumor sequencing datasets. To molecularly characterize PDAC-innervating neurons at single-cell resolution, we developed Trace-n-seq, a strategy combining Fast Blue–mediated retrograde axonal tracing from tumors or healthy pancreas to their respective ganglia. Individual FB+ neurons are isolated from the ganglia by FACS and their transcriptomes established by single-cell RNA sequencing. Using this approach, we established transcriptomic profiles of >5,000 sympathetic and sensory neurons and >4,000 neurons innervating PDAC or healthy pancreas. Our analyses reveal previously unrecognized neuronal cell types and molecular networks that distinguish PDAC-innervating neurons from those associated with healthy pancreas or pancreatitis. Integration of neuronal and TME single-cell datasets delineates cancer-induced reprogramming of neuronal states, identifies a pancreatic cancer–nerve signature, and defines a neuro–cancer–microenvironment interactome. Functionally, pharmacological denervation induces a pro-inflammatory TME and enhances immune-checkpoint inhibitor efficacy. In addition, nab-paclitaxel induces intratumoral neuropathy by blocking sensory neuron activity, attenuating PDAC growth; when combined with sympathetic denervation, this approach results in synergistic tumor regression (Thiel et al., Nature, 2025).Together, our multidimensional analyses provide new insights into the networks and functions of pancreas- and PDAC-innervating neurons with direct clinical implications. These findings are being translated into SYNERGY, a multicenter phase I/II clinical trial combining targeting of celiac ganglion–derived innervating nerves with therapies that directly target PDAC cells. Citation Format: Andreas Trumpp. Neuronal innervation of pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(8_Suppl):Abstract nr SY04-02.

Cancer is characterized by complex interactions across genetic, cellular, and microenvironmental scales. However, a quantitative understanding of how these interactions shape clinical trajectories remains limited. Here, we present a multi-scale single-cell dataset from 184 treatment-naive acute myeloid leukemia (AML) patients spanning all major genetic subtypes, together with an analytical framework to dissect interactions across biological scales. We show that distinct clinical outcomes are encoded by specific cross-scale, cross-compartment interactions present at diagnosis: response to induction therapy is governed by interactions between genetic alterations and leukemic differentiation state; relapse following chemotherapy is associated with non-genetic programs linked to metabolism; and relapse after allogeneic stem cell transplantation is driven by interactions between the immune microenvironment and residual healthy hematopoiesis. Together, our study provides a framework to resolve intra- and inter-patient heterogeneity in cancer and supports a model in which clinical trajectories in AML emerge from defined interactions across biological scales.

Somatic mutations inactivating Tet methylcytosine dioxygenase 2 (TET2) are among the most common drivers of clonal hematopoiesis (CH). TET2 inactivation is associated with monocyte-derived inflammation and improved chimeric antigen receptor T-cell function, suggesting that it might also affect immunotherapy response. In this study, we found that hematopoietic Tet2 mutation in mouse models enhanced the immune checkpoint blockade (ICB) response, which required the combined presence of phagocytes, CD4+, and CD8+ T cells. The effect was lost with myeloid- or T-cell-restricted Tet2 inactivation or in mice with 20% Tet2-mutant hematopoiesis. Mechanistically, in Tet2-mutant tumor-infiltrating leukocytes, ICB preferentially restricted cell states linked to tumor progression while inducing antitumor states. Tet2-mutant monocytes activated costimulatory programs, whereas Tet2-mutant T cells showed enhanced T-cell memory signatures, alongside decreased exhaustion and regulatory phenotypes. Clinically, tumors from patients with colorectal cancer and melanoma with TET2-mutant CH showed enhanced immune infiltration, inflammation, and T-cell activation. In patients with melanoma treated with ICB, TET2-mutant CH was associated with six-fold greater odds of clinical benefit. Collectively, this work demonstrates that hematopoietic TET2 inactivation primes leukocytes for antitumor states associated with immunotherapy response and provides a potential biomarker for personalized therapy. SIGNIFICANCE:TET2 mutations promote antitumor leukocyte states that can potentiate the efficacy of immunotherapy with checkpoint blockade. See related commentary by Yuan and Guryanova, p. 825.

Abstract Background: CYP3A5 expression is a basal and acquired mechanism of resistance of pancreatic ductal adenocarcinoma cells. Inhibition or knockdown of CYP3A5 restores the cells' sensitivity to paclitaxel in vitro. Hence, the addition of a CYP3A5 inhibitor to a paclitaxel-based chemotherapy regimen may re-sensitize resistant clones and confer clinical benefit. Since systemic paclitaxel exposure is determined by CYP3A and CYP2C8 activity, we anticipated the necessity to adapt the dose to account for a pharmacokinetic drug drug interaction. Methods: We conducted a single-center phase I 3+3 dose escalation trial exploring the safety, tolerability and pharmacokinetics of the novel combination of nab-paclitaxel, gemcitabine, and the CYP inhibitor cobicistat in patients with metastatic pancreatic cancer (NCT05494866). We planned with three dose levels (DL) of nab-paclitaxel (DL1: 75 m/m², DL2: 100 mg/m², DL3: 125 mg/m² d1, d8, d15, Q4W i.v.). Gemcitabine (1000 mg/m² d1, d8, d15, Q4W i.v.) and cobicistat doses (continuous 150 mg p.o. qd starting with C1D11) were the same in all DL. We collected serial plasma samples on day 1 and day 15 of cycle 1 to measure drug and metabolite plasma concentrations through UPLC MS/MS. We measured radiological response to treatment every 6-12 weeks according to RECIST 1.1. Patients were followed up for overall survival (OS). Results: We enrolled six patients in DL1. One patient was hospitalized after 6 weeks of treatment for grade 4 acute respiratory distress syndrome associated with LDH increase and lung ground-glass opacity in the CT scan. Two more asymptomatic cases of ground glass opacity associated with LDH increase were observed. We terminated the trial for safety concerns, even though none of the events formally fulfilled DLT criteria. The pharmacokinetic profile showed a minor increase in paclitaxel exposure (AUC-ratio [90% confidence interval]: 1.24 [1.06-1.45]), a moderate increase of 6-OH-paclitaxel (AUC ratio: 2.47 [1.24-4.92]), and a minor increase in gemcitabine AUC). Median progression free survival was 1.89 months and median OS was 4.54 months. Conclusions: Overall, the combination of gemcitabine and nab-paclitaxel with continuous dosing of cobicistat is not safe at the lowest explored dose. We observed pulmonary toxicity with ground glass opacity and LDH increased associated with ∼2.5-fold increased 6-OH-paclitaxel levels. Higher metabolite levels were associated with increased severity of findings. Patient outcome did not warrant continuation of the trial. The results of this trial will inform future strategies for targeting CYP3A5 in pancreatic cancer. Potential approaches may be intermittent CYP3A inhibition, use of a specific CYP3A5 inhibitors, or local target inhibition. Citation Format: Nicolas Hohmann, Martin R. Sprick, Marietta Kirchner, Lucian Le Cornet, Azaz Ahmed, Markus Kratzmann, Joge-Jossy Tonison, Jacek Stermann, Amina Cheikh Rouhou, Karen Steindorf, Stefan Delorme, Heinz-Peter Schlemmer, David Czock, Jürgen Burhenne, Jacek Hajda, Jens T. Siveke, Thomas Seufferlein, Albrecht Stenzinger, Guy Ungerechts, Dirk Jäger, Andreas Trumpp, Christoph Springfeld. Pulmonary toxicity associated with increased 6-OH-paclitaxel exposure in pancreatic cancer patients treated with nab-paclitaxel, gemcitabine and cobicistat: Results of the IntenSify trial [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(8_Suppl):Abstract nr CT186.

Metastasis remains the leading cause of cancer-related mortality and is driven by pronounced tumour cell plasticity1. Here we identify the transmembrane glycoprotein trophoblast cell-surface antigen 2 (TROP2) as a marker of poor-prognosis colorectal cancer (CRC) associated with WNTlow, fetal-like tumour cell states that are linked to metastasis and therapy resistance. Functional analyses demonstrate that TROP2+ cells exhibit context-dependent stem-like capacity and the ability to initiate metastatic outgrowth. Given that these detrimental tumour states converge on the cell-surface antigen TROP2, we explored therapeutic targeting of this cell population using clinically relevant TROP2-directed antibody-drug conjugates. Time-resolved analyses reveal therapy-associated dynamics in tumour cell state composition between WNThi LGR5+ states and WNTlowTROP2+ fetal-like states. Conventional chemotherapy promotes the induction of TROP2-expressing cells, whereas TROP2 antibody-drug conjugates selectively target these populations and remodel the tumour cell state landscape. Exploiting this plasticity, combined chemotherapy and TROP2 targeting enhances anti-tumour efficacy in patient-derived models. Together, our findings identify TROP2 as a therapeutic vulnerability of CRC and highlight the importance of targeting tumour cell states to improve therapeutic efficacy and overcome resistance in advanced disease.

Multidisciplinary tumor boards integrate longitudinal treatment histories, molecular profiling and rapidly evolving evidence to guide decisions in hematological malignancies, yet access to this level of subspecialty deliberation is increasingly uneven. Here we develop HemaGuide, a locally deployable, modular large language model agent that converts unstructured clinical documents into structured case representations, autonomously routes cases to specialized decision modes ('guideline', 'advanced' and 'molecular') and grounds recommendations in disease-specific guideline flowcharts and a clinical decision memory of >2,000 real-world tumor board cases. In expert-blinded benchmarking on 45 high-complexity cases across six foundation models, HemaGuide substantially improved concordance with tumor board decisions. A systematic ablation study across 11 layers confirmed that performance gains were routing-type-dependent, with no single component sufficient across case types. Automated classification of 70 clinically relevant missense variants showed high concordance with expert standards; no oncogenic variant was downgraded to benign and the whole workflow was completed under real-time conditions on commodity hardware with a median latency of 39 s rather than the hours typically required for manual molecular board workflows. In a simulated practice study, agent-assisted resident physicians achieved near-senior concordance and partially outperformed senior physicians in their subspecialty. External validation on 555 independent cases from a second academic center yielded 81.8% concordance across 47 entities, and a prospective 1-month silent trial on 64 consecutive, unselected cases achieved 82.8% concordance. Hallucinations occurred in 2 of 664 evaluated cases (0.3%). Together these data provide evidence that locally deployable, case-grounded large language model agents can deliver auditable clinical decision support across hematological malignancies, with concordance maintained across institutions and under real-time conditions on commodity hardware.

OBJECTIVES:The aim is to investigate the proteomic profile of different molecular subtypes of pancreatic ductal adenocarcinoma (PDAC) and understand their impact on patient outcomes, particularly focusing on pathways involved in xenobiotic metabolism and drug resistance. MATERIALS AND METHODS:The study utilized the serum-free PACO cell culture model and a quantitative prefractionation-based MALDI/MS approach to establish the proteomic profiles of various PDAC subtypes. Differential protein regulation was analyzed to identify systematic alterations in metabolic and drug resistance pathways. Mechanistic studies involved the knockdown and overexpression of key proteins to assess their role in drug resistance. RESULTS:Proteomic analysis revealed subtype-specific alterations, particularly in pathways associated with xenobiotic metabolism and drug resistance. Notably, CYP2S1, a member of the CYP450 family, was upregulated in the HNF1A+ PDAC subtype. CYP2S1 levels were further inducible by polyaromatic hydrocarbons (PAHs) and SN38, the active metabolite of irinotecan via AHR. Mechanistic studies demonstrated that knockdown of AHR or CYP2S1 sensitized PDAC cells to SN38, whereas overexpression of CYP2S1 increased resistance to SN38. CONCLUSIONS:The findings highlight the significant role of CYP2S1 in mediating drug resistance in certain PDAC subtypes. Targeting CYP2S1 and its regulatory pathways could enhance the efficacy of chemotherapeutic agents like irinotecan in treating PDAC. These results provide new insights into the molecular mechanisms underlying PDAC subtype-specific drug resistance and suggest potential therapeutic targets.

Both the nervous system and cancer-intrinsic neural features can govern cancer initiation, growth, progression, metastasis, and treatment resistance, while cancer can likewise influence the nervous system, promoting neural reprogramming and neuropsychiatric symptoms that worsen patient outcomes. The field of cancer neuroscience seeks to unravel this complex neuro-cancer crosstalk and holds the promise to develop neuroscience-instructed cancer therapies that improve disease control and quality of life. Here, we summarize the key discoveries of neuro-cancer crosstalk to date, including neuron-to-cancer synapses and paracrine and neuro-immuno-oncological interactions, and then explore emerging topics such as downstream effects on cancer cell pathophysiology, circadian influences, brain-body-cancer communication, and neural regulation of the metastatic cascade and the tumor microenvironment. Finally, we distill overarching principles, highlight relevant ongoing research, and outline conclusions to guide the development of cancer neuroscience, proposing hypotheses for future experimental validation.

We present Ultra-Content Screening (UCS), a novel, scalable method combining cyclic immunostaining with high-dimensional image-based single-cell proteomics. UCS utilizes fluorescein isothiocyanate-conjugated antibodies and iterative staining-photobleaching cycles to analyze up to 40 markers in up to 100,000 peripheral blood mononuclear cells per experiment. Through precise image registration, nuclear segmentation, signal harmonization, and normalization, UCS ensures the robust tracking of individual cells across all staining cycles. Data analysis via SPADE trees allows qualitative evaluation of expression patterns and cellular phenotypes. Application to samples from acute myeloid leukemia patients demonstrates UCS potential to uncover disease-specific expression profiles and immune subpopulations. The method provides unprecedented depth in single-cell proteomic analysis of blood samples, offering valuable insights for diagnostics, personalized medicine, and therapeutic approaches. ### Competing Interest Statement The authors have declared no competing interest. Helmholtz Imaging Platform HIP

Tet2het dendritic cells do not costimulate CD8 T cells more potently than their wild type counterparts