Nature Cancer

Children with relapsed or refractory acute lymphoblastic leukemia (ALL) require more effective and less toxic therapies. We established a prospective, multicenter Drug Response Profiling (DRP) registry (NCT06550102) integrating functional testing into precision-guided treatment. DRP was performed for 340 patients from 17 European countries with a turn-around time of two-weeks. Image-based drug screening with over 135000 unique perturbations revealed a heterogeneous landscape of ex vivo responses to 88 drugs on average. Ranking drug responses across the patient cohort defined individual drug fingerprints, identifying "DRP twins" by similarity in sensitivity and resistance independent of genetic ALL subtypes. Of 239 high-risk patients with follow-up, DRP-informed interventions were reported for 63 patients (26%). Patients received combination therapies based on venetoclax, tyrosine kinase inhibitors, trametinib, bortezomib or selinexor, resulting in objective clinical responses in 43 cases (68%). Precision-guided treatments allowed bridging to cellular therapies in 42 patients among whom 28 (67%) were still alive with a median follow-up of 21 months after DRP (IQR: 14.7-26.6 months). Top responders to venetoclax, ranked within the first tertile of the cohort, had superior 1-year event-survival compared to venetoclax non-responders (0.57 [95% CI, 0.39-0.85] vs. 0.25 [95% CI, 0.11-0.58]). Collectively, these findings demonstrate the feasibility and clinical relevance of functional profiling within an international network. This scalable framework enables individualized therapy selection for enrolment in adaptive precision trials for high-risk pediatric ALL.

Pancreatic ductal adenocarcinoma (PDAC) is typically diagnosed at advanced stages, yet single-cell datasets that capture late-stage and treated disease remain sparse, hindering progress in understanding tumour heterogeneity and therapy resistance. Here, we have generated integrated single-cell transcriptomic atlases of human and mouse PDAC to define the cellular and molecular landscape of the disease, from early to advanced and metastatic stages, including post-treatment disease, and to enable direct cross-species comparison. Using scANVI to harmonize 16 human studies comprising 257 donors and representative mouse models (101 tumours), we compiled over 1.6 million cells and established a four-level hierarchical taxonomy of more than 60 distinct cell states spanning malignant, stromal, immune, endothelial, adipose, exocrine and endocrine compartments. We resolve ten malignant programmes linked to progression and uncover rare immune phenotypes, including CD4CD8 double-positive T cells that remain poorly characterized in PDAC. Notably, we show that radiotherapy (RT) exposure is associated with enrichment of an EMT-persistent malignant state and an immunosuppressive microenvironment characterized by expansion of tumour-associated endothelium, depletion of intratumoral T cells and heightened laminin-CD44 signalling, with RT-associated genes linked to adverse prognosis in independent cohorts. Cross-species mapping reveals that orthotopic syngeneic allografts more faithfully recapitulate the cellular diversity and EMT-enriched states of advanced human PDAC, underrepresented in autochthonous genetically engineered models, with differences driven primarily by cell-type composition rather than pathway divergence. Together, these atlases and pretrained models provide a broadly accessible reference for benchmarking PDAC model fidelity and for interrogating mechanisms of tumour progression, microenvironmental remodelling and therapy response and resistance.

Triple negative breast cancer (TNBC) patients harboring residual cancer burden following completion of conventional neoadjuvant chemo-immunotherapy regimens have poor relapse-free and overall survival rates despite recent advances in immunotherapies and antibody drug conjugates. We and others have demonstrated the requirement of mitochondrial function for survival of chemo-refractory TNBC, as well as its pervasive association with chemoresistance in human and patient-derived xenograft (PDX) cohorts. We sought to gain new mechanistic insights into the mitochondrial vulnerability of TNBC. Analyses of human and PDX mass spectrometry proteomics datasets revealed that mitochondrial protein translation-related signatures were among the top significantly associated with chemoresistance. Those signatures encompassed many core mitoribosome components as well as the mitoribosome accessory protein, Oxidase (Cytochrome C) Assembly 1-Like (OXA1L), which was consistently enriched in chemoresistant versus chemosensitive TNBCs across datasets. OXA1L, while not yet characterized in cancer, has been reported to be crucial for the termination of translation of the 13 mtDNA-encoded electron transport chain (ETC) proteins and for the insertion of those proteins, as well as nDNA-encoded ETC proteins, into the inner mitochondrial membrane. Together, those functions are crucial for the proper formation and function of the ETC. Therefore, we hypothesized that mitochondrial translation supported by OXA1L supports mitochondrial dependence and chemoresistance in TNBC. Knockdown (KD) of OXA1L in human TNBC cells reduced ETC protein levels, mitochondrial respirasome supercomplex levels, ATP production, and oxidative phosphorylation (oxphos). Of note, OXA1L was required for the characteristic oxphos elevation induced by carboplatin (CRB), and KD significantly enhanced CRB sensitivity. To explore the translational potential of targeting the mitoribosome in TNBC, we leveraged the bacterial ancestry of mitochondria to repurpose the FDA-approved antibiotic tigecycline (TIG) as a chemo-sensitizing drug based on its mitoribosome inhibitory function. Direct measurement of mitochondrial nascent peptide levels revealed that, while CRB elevated mitochondrial translation, TIG potently diminished mitochondrial translation as monotherapy and when combined with CRB or docetaxel (DTX). Further, TIG abolished CRB-induced oxphos, decreased oxphos in combination with DTX, and significantly improved sensitivity to chemotherapies in human TNBC cell lines, PDX-derived spheroids, and in an in vivo PDX trial. These findings identify OXA1L-dependent mitochondrial translation and ETC formation as critical determinants of mitochondrial function that support TNBC chemoresistance, justifying further exploration of the clinical potential of repurposed antibiotics for TNBC. DISCLOSURESGVE is co-founder, Chief Scientific Officer, and an equity stakeholder of Nemea Therapeutics. G.V.E. formerly received sponsored research funding from Chimerix Inc. G.V.E. receives experimental compounds from the Lead Discovery Center of Germany and from Jazz Pharmaceuticals. MLB is a co-inventor at Nemea Therapeutics. MTL is a founder and limited partner in StemMed Ltd. and a manager in StemMed Holdings, its general partner. He is a founder and equity stakeholder in Tvardi Therapeutics Inc. Some PDX models, including BCM-4272 and BCM-7649, are exclusively licensed to StemMed Ltd., resulting in royalty income to MTL when used for commercial purposes. LED is a compensated employee of StemMed Ltd. Some PDX models, none of which are included in this study, are exclusively licensed to StemMed Ltd., resulting in royalty income to LED. All other authors have nothing to disclose.

As solid tumors progress, the tumor microenvironment (TME) becomes increasingly immunosuppressive, impairing cytotoxic T-cell activity and limiting the efficacy of the immune checkpoint blockade. However, the mechanistic drivers of this immunosuppression remain poorly understood. Here, we identify a tumor-derived lipid-neutrophil-adenosine axis as a critical regulator of immune suppression in advanced colorectal cancer (CRC). We show that fatty acids enriched in tumor interstitial fluid reprogram neutrophils to generate adenosine via PPAR activation, leading to T-cell suppression. Using AB928, a dual A2aR/A2bR adenosine receptor antagonist currently in clinical trials, we restored T-cell proliferation, effector function, and tumor-killing capacity in vitro and in vivo. Importantly, AB928 synergized with anti-PD-1 therapy to enhance survival in an autochthonous model of metastatic CRC. Our findings define a metabolic immune evasion mechanism in the TME and provide a rationale for targeting neutrophil-derived adenosine signaling to improve immunotherapy responses in CRC and other solid tumors.

Immune checkpoint inhibitors (ICI) improved outcomes in metastatic urothelial carcinoma (mUC), but primary and acquired resistance remain poorly understood. We performed single-nuclei RNA sequencing on sequential metastatic biopsies from ICI-treated mUC patients. Tumor cells showed transcriptomic heterogeneity within individual lesions, basal cells being associated with increased immune infiltration and response. Myeloid and lymphoid compartments exhibited features of immune dysfunction in non-responders. Longitudinal analyses revealed convergent adaptive resistance mechanisms, dominated by polarization toward pro-tumoral macrophage states, but also including downregulation of the antigen presentation machinery in tumor cells, increased checkpoint expression with loss of cytotoxicity in T cells. Individual trajectories point to distinct evolutionary routes under ICI pressure. Across pivotal ICI trials, bulk expression of the M2-like macrophage marker HES1 predicted ICI resistance. Our study provides the first single-cell longitudinal atlas of ICI-treated mUC, revealing macrophage reprogramming as a dominant driver of resistance, establishing a framework for individualized immunotherapy strategies.

Although inhibitors of oncogenic KRAS have shown clinical efficacy1, resistance to KRAS inhibition is common2, and its molecular basis remains unclear. Here we show that KRASi-resistant cancer cells sustain mitochondrial bioenergetics through enhanced fatty acid (FA) metabolism, despite suppression of canonical KRAS signaling. Specifically, KRASi-resistant pancreatic cancer cells exploit macropinocytosis to scavenge FA released from adipose tissue, fueling beta-oxidation independently of KRAS-PI3K signaling. This adaptive metabolic program is driven by the adhesion G protein-coupled receptor ADGRB1, which activates non-canonical PI3K{gamma}-PAK1 signaling to stimulate macropinocytosis and maintain metabolic homeostasis under KRASi. Disruption of ADGRB1-PI3K{gamma} signaling dismantles this metabolic program and restores KRASi sensitivity. This pathway operates across multiple KRAS-mutated cancers and is associated with poor therapeutic response and outcome. These findings offer a promising strategy for overcoming KRASi resistance.

Bispecific T-cell engagers stimulating CD3 (TCEs) rapidly gain momentum in oncological therapy. We report that single-agent TCE-treatment of cancer patients induces T-cell hyporesponsiveness including abolished proliferative and lytic capacity. Single-cell RNA-sequencing identified transcriptional features of anergy/quiescence like upregulation of CBLB and BACH2, and suppression of AP-1-dependent activation programs due to isolated provision of "T-cell signal-1". To restore T-cell functionality, we engineered bispecific costimulators (BiCos) which deliver "signal-2" via highly efficient bivalent CD28-binding yet maintain strictly target-restricted activity. Preclinical analyses documented that BiCos potentiate efficacy of single-agent TCE treatment with activity exceeding that of univalent Knob-into-Hole CD28-costimulators and revert T-cell hyporesponsiveness. In humanized mice, BiCos induced elimination of established tumors in combination with very low doses of TCE. Finally, BiCos reversed molecular hallmark features of quiescence such as high expression of BACH2 and KLF2 in T-cells of TCE-treated patients resulting in complete restoration of cellular function, thereby reinstating durable antitumor immunity. Statement of significanceFirst clinical evidence that single-agent treatment with CD3-directed bsAbs induces T-cell hyporesponsiveness resulting in profoundly impaired functionality. Tumor-restricted CD28-costimulation with bsAbs can prevent and revert transcriptional features of anergy/quiescence, establishing conditional delivery of both, T-cell signal- 1 and -2 by combinatorial bsAb treatment as a strategy to improve cancer immunotherapy.

Clinical decision-making relies on understanding intersectional treatment effects across multiple patient characteristics. However, randomized controlled trials typically report one-dimensional marginal summaries, obscuring the underlying joint distributions of these characteristics. To address this, we developed MD-JoPiGo, a computational framework that reconstructs multidimensional clinical profiles from published 1D Kaplan-Meier curves. The approach utilizes the maximum entropy principle to estimate joint stratum frequencies and applies simulated annealing to generate individual-level data. We show that reconstruction fidelity depends on the underlying causal topology. Parallel predictors are resolved unconditionally, whereas interdependent structures require minimal structural priors to resolve unidentifiability. In evaluations using simulated data and empirical cohorts (lung cancer, n = 228; colon cancer, N = 929), the framework accurately recovered unobserved multivariable dynamics. Applied to fragmented and temporally misaligned reports from the CheckMate 227 trial, MD-JoPiGo reconstructed latent intersectional efficacy consistent with the clinical ground truth. By synthesizing multivariable evidence from 1D margins, this framework enables the secondary analysis of historical RCTs, supporting IPD meta-analyses and synthetic trial emulations.

Acute myeloid leukemia (AML) is an aggressive hematologic cancer characterized by proliferation of immature myeloblasts1. It shows profound molecular heterogeneity, which has been primarily studied through genetic abnormalities, providing the basis for disease classification, prognostication, and therapeutic choice2-8. However, genetic factors alone may not fully explain AML pathogenesis and diversity, while leaving the role of abnormal epigenome, particularly chromatin state, largely unexplored in a large cohort of patients. Here we show that AML is classified into 16 subgroups with distinct chromatin accessibility profiles based on ATAC-seq in 1,563 AML cases, derived from the encyclopedia of chromatin in AML (eCHROMA AML) dataset, including novel AML subgroups not previously recognized in conventional genomic classifications. By integrating multi-omics analyses of genome, transcriptome, and major histone marks, we show that these epigenetic subgroups exhibit unique features in clinical presentation, gene mutations, differentiation states, gene expression, and super-enhancer profiles, which are validated across independent cohorts. Single-cell sequencing demonstrates the presence of subgroup-specific ATAC signatures that are shared by all leukemic cells, confirming the key role of the epigenome in the ATAC-based classification. Mechanistically, each subgroup is associated with a distinct gene regulatory network centered on key transcription factors, where subgroup-specific super-enhancers play a pivotal role. These ATAC subgroups also have prognostic significance independent of genomic classification, and help reveal unexpected drug sensitivities. In summary, ATAC-based chromatin profiling in this large sample set, combined with multi-omics data, provides new insights into AML pathogenesis beyond genomic profiling and also serves as an invaluable resource for AML research.

One-carbon metabolism is frequently dysregulated in human cancer including acute myeloid leukemia. However, the mitochondrial mechanisms by which one-carbon enzymes support leukemia survival and therapeutic response remain incompletely defined. Here, we report that the one-carbon metabolism enzyme MTHFD2 is a critical regulator of acute myeloid leukemia nucleotide metabolism, redox homeostasis, and disease progression. We show that genetic ablation of MTHFD2 suppresses acute myeloid leukemia cell proliferation in vitro and significantly delays leukemia onset in a genetically engineered mouse model, while sparing healthy hematopoietic stem and progenitor cell function. Stable isotope tracing demonstrates that MTHFD2 supports de novo purine synthesis and sustains mitochondrial NADH and NADPH production. Consistent with this role, MTHFD2 inhibition increases mitochondrial superoxide levels, and combined purine supplementation and mitochondrial reactive oxygen species neutralization rescues acute myeloid leukemia cell viability. We also demonstrate that the small-molecule inhibitor DS18561882 directly inhibits mitochondrial MTHFD2 activity and phenocopies genetic deletion. DS18561882 exhibits activity across a cohort of 60 primary AML patient samples, synergizes with venetoclax in treatment-naive acute myeloid leukemia, and restores venetoclax sensitivity in resistant AML models. These findings establish mitochondrial MTHFD2 as a genetically validated, therapeutically targetable metabolic vulnerability in acute myeloid leukemia and support targeting mitochondrial one-carbon metabolism to enhance and restore venetoclax response.

An immunosuppressive tumor microenvironment limits therapeutic efficacy and worsens prognosis in melanoma. Beyond T-cell abundance and function, effective tumor control also depends on whether T cells can access malignant cells within the tumor. Although emerging evidence supports that tumor vasculature facilitates immune evasion, the vascular mechanisms that govern intratumoral T-cell positioning remain poorly defined. Using RNA sequencing of endothelial cells isolated from tumor cores versus peripheries in a mouse melanoma model, we identified intercellular adhesion molecule 1 (ICAM-1) as a candidate regulator of T-cell localization. During tumor growth, T cells shifted from a balanced core-margin distribution to marked exclusion from the core, most prominently in T cell-inflamed tumors. This spatial redistribution --less evident in other immune subsets--coincided with high expression of lymphocyte function-associated antigen-1 (LFA-1) on T cells. In parallel, endothelial ICAM-1 became enriched at the tumor periphery, where vascular integrity was compromised, as evidenced by increased vascular leakage and reduced pericyte coverage. Functionally, ICAM-1 blockade restored intratumoral T-cell infiltration, enhanced effector activity, and significantly delayed the growth of immunogenic tumors. Moreover, ICAM-1 inhibition sensitized an immune-refractory tumor to anti-PD-1 checkpoint blockade. Together, these findings identify endothelial ICAM-1 as a vascular determinant of intratumoral T-cell positioning and highlight the ICAM-1/LFA-1 axis as a modifiable checkpoint to reverse T-cell retention at the tumor periphery, thereby enhancing antitumor immunity and immunotherapy efficacy.

Poor intratumoral drug penetration and short-lived therapeutic exposure limit durable responses to cytotoxic therapies. We developed a strategy that redirects an evolutionarily optimized clotting cascade to achieve selective, sustained drug deposition within solid tumors. A vascular disrupting agent induces tumor-specific endothelial injury and platelet activation, exposing GPIIb/IIIa. Systemically administered fibrinogen-drug nanoparticles (FDNs) bind activated platelets with multivalent avidity, amplify thrombus formation, and become immobilized within tumor vessels, creating an intratumoral drug depot that maintained paclitaxel above cytotoxic levels for over 10 days. A single 15-minute treatment eradicated advanced triple-negative breast tumors in 88% of mice, while docetaxel-based FDNs produced durable eradication of pancreatic tumors in all treated mice (9/9). These findings establish a clinically translatable clot-guided platform for sustained therapeutic exposure in refractory cancers.

Although small cell lung cancer (SCLC) comprises transcription factor (TF)-defined molecular subtypes (ASCL1, NEUROD1, POU2F3), the extent to which these subtypes predict response to clinically effective therapy in patients--and whether therapy can select for subtype switching--remains unknown. The recent approval of the DLL3xCD3 bispecific T-cell engager tarlatamab represents one of the first meaningful advances in relapsed small cell lung cancer (SCLC) in decades, yet responses remain heterogeneous and resistance is inevitable. Here, we inferred SCLC gene expression from circulating chromatin in prospectively collected patient plasma (46 patients; 167 samples), enabling interrogation of response and acquired resistance to tarlatamab. Parallel development of the first immunocompetent syngeneic mouse model to study tarlatamab response and resistance enabled functional validation. Across species, findings converged on a central principle: TF subtype governs both initial response and acquired resistance. Therapeutic response was significantly associated with ASCL1-subtype tumors, whereas NEUROD1-subtype tumors exhibited inferior responses and POU2F3-subtype tumors were uniformly resistant, consistent with DLL3 being a direct ASCL1 transcriptional target and most highly expressed in ASCL1-positive tumors. Strikingly, one mode of acquired resistance revealed therapeutic selection for a NEUROD1-high state with concomitant DLL3 downregulation. Other resistant tumors exhibited enrichment of regulatory and exhausted T-cell programs, highlighting tarlatamabs dual-targeting mechanism of action. Together, these results reveal that tarlatamab exerts selective pressure against ASCL1-driven lineages, facilitating resistance through loss of an antigen intrinsically linked to that state. These findings underscore the clinical relevance of TF-defined molecular subtypes in human SCLC. More broadly, they highlight the power of integrating longitudinal in vivo plasma transcriptional profiling from patient plasma with functional mouse modeling to uncover clinical and biological mechanisms of response and resistance to cell-surface-targeted therapies.

The high heterogeneity of pediatric cancers presents significant diagnostic challenges, underscoring the need for accurate classification. Although molecular profiling supports first-line diagnostics and guides treatment, it can delay final diagnosis. While Nanopore-based methylation analysis has enabled rapid CNS tumor diagnosis, its application to pediatric solid tumors and lymphomas has remained largely unexplored. We developed Tucan, a deep-learning classifier trained on 3,818 methylation array profiles representing 84 subtypes, designed to classify tumors from sparse Nanopore methylation data. In retrospective validation (n=514), Tucan generated confident predictions (CFT[≥] 0.7) within 30 minutes of sequencing in 385 cases, achieving 372 correct diagnoses (F1-score: 0.98). In prospective testing (n=74; 63 classifiable), 52 samples reached the confidence threshold with 96% accuracy, confirming the original diagnosis in 47 cases and correctly refining or revising it in three. Together, Tucan enables rapid, high-confidence molecular classification of pediatric solid tumors and lymphomas.

Multiple myeloma (MM) is a plasma cell malignancy shaped by dynamic interactions between MM cells and non-malignant cells in the immune microenvironment. To spatially profile the influence of cellular context on MM and immune cell expression, we developed a multimodal framework integrating 10x Genomics Visium HD, 10x Genomics Xenium, and clinically annotated single-cell RNA (scRNA-seq) sequencing datasets. Visium HD enabled unbiased, whole transcriptome, spatial discovery at 16 {micro}m resolution, Xenium provided orthogonal validation at single-cell resolution, and scRNA-seq extended findings by mapping spatial labels and leveraging the greater sequencing depth. We developed a custom framework for cell type annotation within Visium HD spatial bins. Our approach enabled identification of plasma cell-dense niches enriched for non-canonical Wnt signaling, associated with gene expression supporting cell adhesion mediated drug resistance, inferior progression-free survival, and extramedullary lesions. Immune cells within these neighborhoods exhibited suppressed transcriptional states, including increased inhibitory receptor expression such as LAG3. Utilizing the niche-driven transcriptional states in MM and immune cells, we were able to develop a 15-gene signature independently predictive of progression free survival (HR = 2.00, p < 0.0001). Collectively, this study demonstrates the potential of integrated spatial and single-cell transcriptomics to define niche-specific programs supporting MM progression.

Antibody-drug conjugates (ADCs) require high and homogeneous target expression for optimal efficacy, yet the spatial, temporal, and cellular heterogeneity of clinically approved ADC targets in high-grade serous ovarian cancer (HGSC) remains incompletely defined. We analyzed bulk RNA-sequencing, single-cell RNA-sequencing, and whole-genome sequencing data from 867 samples across 304 patients enrolled in the real-world DECIDER cohort to systematically evaluate 11 approved ADC targets. FOLR1, TACSTD2, and ERBB2 emerged as highly expressed candidates. Inter-patient variability exceeded intra-patient heterogeneity, which further decreased following neoadjuvant chemotherapy. Target expression was highly concordant across anatomical sites and largely stable from diagnosis to relapse. Single-cell RNA-sequencing results revealed that TACSTD2 and FOLR1 showed the most frequent cancer cell-restricted expression. In rare cases of gene amplification, ERBB2 and F3 emerged as potential targets alongside TACSTD2 and FOLR1. Overall, 80% of patients displayed homogeneous expression of at least one actionable target, with frequent co-expression of TACSTD2 and FOLR1. These findings indicate that ADC target expression in HGSC is broadly stable across space and time and support the prioritization and strategic integration of TACSTD2- and FOLR1-directed ADCs in this disease.

Thermal ablation is increasingly used for local control of pancreatic ductal adenocarcinoma (PDAC), but its capacity to induce systemic antitumor immunity and the mechanisms limiting this response remain incompletely defined. Using a bilateral LSL-KrasG12D/+; LSL-Trp53R172H/+; Pdx1-Cre (KPC) flank tumor model, we show that serial radiofrequency ablation (RFA) enhances local tumor control and induces a robust abscopal response. This effect was associated with increased activation of CD8 T cells and natural killer cells, and was abrogated by CD8 T cell depletion. Single-cell RNA sequencing revealed expansion of cytotoxic immune programs alongside induction of a CSF1-driven myeloid response consistent with adaptive immune resistance. Although CSF1R inhibition alone was insufficient to improve tumor control, combinatorial blockade of PD-L1 and CD73 augmented systemic antitumor responses, and the addition of CSF1R inhibition in this context further enhanced both local and distant tumor control. These findings identify a CSF1-dependent myeloid resistance program that constrains ablation-induced systemic immunity and demonstrate that rational combination immunotherapy can potentiate the systemic efficacy of tumor ablation in PDAC.

Infections are the most common cause of non-relapse mortality in multiple myeloma (MM), but the basis of persistent immune dysfunction is obscured by patient heterogeneity and complex treatment regimens, including autologous stem cell transplant (ASCT). We performed longitudinal multi-omic profiling of matched bone marrow and peripheral blood from MM patients across diagnosis, induction, ASCT, and recovery. We found the tumor imposes a compartment-specific immune program where the marrow exhibits metabolic and inflammatory changes that bias hematopoiesis and alter cytotoxic effector programs not mirrored in blood. Adaptive immune reconstitution is impaired up to two years post-ASCT. Half of patients fail to mount IgG responses to high-dose non-adjuvanted influenza vaccine, a defect overcome by the lipid nanoparticle (LNP) adjuvanted COVID mRNA vaccine, which elicited responses in all patients, supporting adjuvanted influenza vaccine strategies in MM. Together these findings define how myeloma and its treatment durably reshape immunity from the marrow outward. HighlightsO_LIMultiple Myeloma marrow and blood show opposing metabolic and inflammatory states C_LIO_LIInduction therapy selects durable myeloma plasma-cell transcriptional states C_LIO_LIB cell and follicular helper T deficits blunt antigen responses after transplant C_LIO_LICOVID-19 vaccination builds immune memory with variable responses to flu vaccination C_LI eTOCMultiple myeloma and its treatment leave a lasting imprint on the bone marrow niche. By profiling bone marrow and blood longitudinally at diagnosis, through induction, autologous transplant, and recovery, we show that marrow-local metabolic and inflammatory constraints persist and help explain why influenza vaccination often fails while mRNA vaccination succeeds.

Chemotherapy resistance in pancreatic ductal adenocarcinoma is commonly attributed to tumor cell-intrinsic mechanisms, yet how cytotoxic therapy reshapes the tumor microenvironment remains incompletely understood. Here we show that PDAC cells exposed to cytotoxic agents reprogram pancreatic stellate cells toward an inflammatory cancer-associated fibroblast phenotype. Mechanistically, chemotherapy triggers the release of ATP from dying PDAC cells, which activates P2X7 signaling in PSCs in a paracrine manner, leading ERK activation and inflammatory polarization. In turn, therapy-educated PSCs promote tumor cell proliferation, induce resistance-associated transcriptional programs and impair CD8 T cell-mediated cytotoxicity in an IL-6-dependent manner. Pharmacological inhibition of P2X7 suppressed stromal IL-6 induction and enhanced gemcitabine efficacy in vivo. These findings identify a therapy-induced ATP-P2X7-IL-6 axis that links tumor cell death to stromal reprogramming and adaptive resistance in PDAC.

Myelofibrosis in patients with myeloproliferative neoplasms (MPNs) is traditionally characterized by bone marrow fibrosis and osteosclerosis, with de novo bone formation commonly attributed to impaired osteoclast-mediated resorption. Here, we challenge this paradigm by demonstrating that a solitary clonal driver mutation simultaneously induces pathological bone formation and resorption, with osteosclerosis acting to conceal localized and active bone destruction rather than inhibiting it. Through population analysis; clinical imaging; patient-derived multi-tissue sequencing; murine models and organ-on-a-chip systems, we demonstrate that spatial and ontogeny-dependent remodeling in mesoderm- and neural crest-derived bones is mechanistically interconnected via a previously unidentified osteochondral stromal injury program. Neural crest-derived stromal cells suppress osteogenic programs and undergo injury-induced lineage plasticity with ectopic chondrogenesis, mirroring pathological remodeling in mesoderm-derived growth plate regions. This shared injury response promotes osteoclastogenesis and is mediated by a conserved Thrombospondin 1+ (THBS1+) stromal population that links fibrotic remodeling to bone loss. Combined pharmacological inhibition of THBS1 and JAK signaling reduces myeloproliferation, halts fibrosis progression, and restores two developmentally distinct bones, establishing THBS1 as a unifying therapeutic target in myelofibrosis.