Cell & Bioscience

Early pregnancy requires a tightly regulated pro-inflammatory environment shared between the primitive placenta and decidua. While immune balance supports successful implantation and placental invasion, disruptions in immune signaling during this period can impair implantation and lead to embryo loss. In this study, we investigated the molecular mechanisms underlying immune imbalance during implantation using a trophoblast stem cell (TSC) model. TSCs were cultured in either stem cell or syncytiotrophoblast (STB) differentiation medium and treated with either lipopolysaccharides (LPS) or interferon beta (IFNB). RT-qPCR and Western blotting revealed that LPS failed to induce a pro-inflammatory cytokine response in TSCs or STBs. In contrast, IFNB triggered a strong antiviral response in both TSCs and STBs. RNA-sequencing of IFNB-treated TSC and STB 3D spheroids revealed subtle differences between the TSCs and STB responses to interferons. Both TSC and STB IFNB-treated spheroids mount an interferon-mediated antiviral response; however, STB spheroid genes associated with the type I interferon response, viral RNA/DNA sensing, and antigen processing were upregulated. We also compared the interferon response between the CT27 (female) and CT29 (male) TSCs and STBs. While STBs showed minimal differences, the CT29 TSCs exhibited a markedly stronger interferon response than the CT27 TSCs. Collectively, these findings suggest that the primitive placenta is selectively responsive to interferon signaling rather than direct pathogen-associated stimuli. This implies that maternal immune activation, rather than microbial invasion, likely drives that placental immune response and embryo success at this stage. Understanding these dynamics underscores the importance of the maternal immune balance in early pregnancy success.

Importance: Non-medullary thyroid cancer (NMTC) and melanoma are associated with inherited long telomeres due to germline pathogenic/likely pathogenic variants (PV/LPV) in POT1, TINF2, and ACD resulting in long-telomere syndrome (LTS) and they commonly have somatic TERT promoter mutations. The genetic relationship between these variants and their clinical associations are defined incompletely and may inform clinical practice. Objective: To test the hypothesis that germline LTS-associated PV/LPV are exclusive from functional somatic TERT variants and assess clinical/genetic associations. Design: Retrospective observational cohort study with/without germline LTS variants, that have somatic sequencing and pathology data. Setting: Participants were enrolled through 18 cancer centers participating in the Oncology Research Information Exchange Network (ORIEN). Participants: 995 adults with NMTC and 993 with melanoma between 2013 and 2025. All adult patients at an ORIEN center were offered enrollment Exposures: All patients with NMTC or melanoma are included. There are no required exposures. Main Outcomes and Measures: The presence/absence of a germline or somatic long-telomere variant; secondary outcomes are associations with tumor stage, telomerase expression, and oncogenes. Results: Germline and somatic variants in POT1/TINF2/ACD, somatic TERT promoter variants, TERT fusions, oncogenes, and telomerase mRNA expression were evaluated in 995 NMTC and 993 melanoma patients. In NMTC, 13 (1.5%) had a germline LTS variant while 0/12 with tumor sequencing had somatic TERT promoter variants/fusions. In melanoma, 7 (0.7%) had a LTS variant; 0/2 with tumor sequencing had a TERT promoter variant/ fusion. Meta-analysis including NMTC and melanoma in the current study, a recent thyroid cancer study, and thyroid TCGA, germline LTS-associated PV/LPV and somatic TERT variants/fusions were mutually exclusive (p=0.036). High telomerase mRNA levels were associated with TERT promoter variants/fusions (p<4e-11) and larger NMTC/distant metastases (p=0.016), but not germline LTS variants. NMTCs with somatic TERT promoter variants/fusions had higher tumor mutation burden (p<0.02) versus tumors from patients with a germline LTS variant. TERT promoter mutant variant allele frequency was lower in smaller and non-metastatic vs larger/metastatic NMTC. Conclusion and Relevance: Germline LTS-associated variants appear to be exclusive from somatic TERT promoter variants/fusions but are not associated with aggressive NMTC, suggesting common roles in tumorigenesis but different biological impacts.

Neurofibromatosis type 1 (NF1) is a common autosomal dominant genetic tumor predisposition syndrome.1 NF1 patients display remarkable phenotypic variability, even within families carrying the same NF1 mutation.2 With few exceptions, the identification of specific genotype-phenotype correlations has remained elusive.3-6 We utilized RNA-seq data and direct DNA sequencing to determine HLA genotypes for individuals with NF1-associated high-grade glioma (HGG, n=25), low-grade glioma (LGG, n=79), and malignant peripheral nerve sheath tumors (MPNST, n=105). Odds ratios (OR), binomial p-values and false discovery values were calculated by comparing observed carrier frequencies against expected frequencies derived from ethnicity-matched population data. We find that specific HLA class I and II alleles are associated with different NF1 tumor types. For example, HLA-B*40:02 is significantly associated with NF1-MPNST (OR=3.71, p=0.001, Q=0.02), increasing the lifetime risks for MPNST from 10% to about 29%. The relative cancer risk for an individual in the general population carrying a risk allele can be high, however, that individuals absolute risk for cancer typically remains very low. In contrast, individuals that carry a risk allele and are also burdened with a tumor predisposition syndrome will have a substantially higher absolute risk to develop a tumor, simply because they start at a higher baseline susceptibility for tumors. The identification of HLA-risk alleles for NF1 tumor development is therefore important, as it will allow for a risk-adapted screening or more aggressive treatment of individuals with a specific HLA haplotype. If confirmed, this study will thus improve clinical care and potential outcomes of individuals with NF1.

Melanoma remains one of the most treatment-refractory malignancies due to immune evasion, high mutational burden, and profound tumor heterogeneity. Although immune checkpoint inhibitors have transformed frontline management, a substantial proportion of patients develop resistance or experience relapse, underscoring the need for alternative and complementary immunotherapeutic strategies. Tumor-infiltrating lymphocyte (TIL) therapy and engineered viral vector-based immunotherapies represent mechanistically distinct yet clinically promising approaches for advanced melanoma. This systematic review and Bayesian meta-analysis evaluated the comparative efficacy of TIL therapy and engineered viral vector immunotherapies in advanced melanoma. A structured search of PubMed, Embase, Scopus, and Web of Science (2015-2025) identified 13 eligible studies, including four randomized controlled trials and nine prospective single-arm studies, reporting objective response rate (ORR), progression-free survival (PFS), overall survival (OS), and treatment-related adverse events. Eight studies met criteria for inclusion in the Bayesian quantitative synthesis of ORR outcomes. Risk of bias and certainty of evidence were assessed using Cochrane and GRADE frameworks. TIL therapy demonstrated substantial standalone efficacy, particularly in PD-1-refractory populations, with reported ORRs reaching 49%, median PFS of 7.2 months, and OS extending to 25.8 months. Viral vector-based therapies, including talimogene laherparepvec (T-VEC) and RP1, showed more modest monotherapy activity but demonstrated improved responses when combined with immune checkpoint inhibitors. Among the studies included in the Bayesian quantitative synthesis, the pooled ORR estimate was 37.8% (95% highest density interval [HDI]: 30.6%-45.3%). Sensitivity analysis excluding the small-sample Cui et al. (2022) study yielded a similar pooled estimate of 38.3% (95% HDI: 30.4%-46.2%). Exploratory meta-regression supported the overall robustness of the findings. Certainty of evidence for ORR was moderate, whereas survival and safety outcomes were downgraded due to heterogeneity, sparse reporting, and inconsistent endpoint definitions. Collectively, these findings support complementary rather than competing roles for TIL and engineered viral vector immunotherapies within evolving melanoma treatment paradigms. The results further highlight the potential importance of biomarker-guided sequencing strategies, including viral immune priming followed by adoptive cellular therapy, as a framework for optimizing personalized immunotherapy in both refractory and earlier-line melanoma settings.

BackgroundRisk stratification for prostate cancer (PCa) progression or aggressiveness is often based on clinicopathologic features, some of which may be influenced by genetic factors. We developed a novel, germline polygenic risk score (PRSagg) to predict likelihood of developing aggressive PCa. MethodsPRSagg was developed using data from 38,688 patients with PCa (case-only analysis) from the Million Veteran Program (MVP) through a genome-wide search for variants associated with PCa grade group at diagnosis. We tested associations of PRSagg with grade group using the entire MVP dataset using the .632 bootstrap method. In an MVP cohort with localized PCa that was initially monitored without treatment, we tested PRSagg for association with unfavorable outcomes (subsequent development of grade group 4-5, metastasis, and/or biochemical recurrence after definitive treatment). We performed external validation in data from patients in the PRACTICAL Consortium (n=45,214) and from participants in the ProtecT randomized trial who underwent active monitoring (n=316). Odds ratios (ORs) were calculated per standard deviation (SD) increase with 95% confidence intervals, while adjusting for age, genetic ancestry, a previously developed polygenic score for risk of PCa (PHS601), and a polygenic score for benign elevated prostate-specific antigen (PRSPSA). For the outcome of metastasis, we additionally adjusted for PSA at diagnosis. ResultsIn the MVP training dataset, PRSagg (172 variants) was associated with higher grade group at diagnosis (OR = 1.53 [1.51-1.56]) and with increased risk of unfavorable outcomes during monitoring (OR = 1.13 [1.09-1.18]). These findings were confirmed in the external datasets. PRSagg was associated with greater odds of higher grade group at diagnosis (OR = 1.09 [1.06-1.11]). Among ProtecT participants undergoing active monitoring, PRSagg was associated with higher risk of metastasis (OR = 2.15 [1.02-3.88]). Among MVP participants with high polygenic risk of developing any PCa, the risk of aggressive disease was highest in men with high PRSagg and low genetic risk of PSA elevation. ConclusionsAmong men who develop PCa, a weighted sum of common germline variants (PRSagg) is independently associated with PCa aggressiveness. These findings may inform future study of germline influence on tumor evolution and risk-stratified intensity of active surveillance.

Tuberculosis (TB) remains a leading global cause of infectious mortality due, in part, to the limited efficacy of the Mycobacterium bovis BCG vaccine against pulmonary TB. Previous studies in mice have shown that stimulating type I interferon (IFN) signaling during BCG vaccination can bolster protection against Mycobacterium tuberculosis, yet clinically feasible delivery strategies for this approach are lacking. Adenoviral vectors, which induce potent type I IFN responses and are utilized in approved vaccine platforms, represent a promising adjuvant strategy. To evaluate the host immune response to this combination, bone marrow-derived murine macrophages were co-infected with replication-deficient adenovirus and BCG. Adenovirus-infected macrophages elicited a robust type I IFN response via the cGAS/STING pathway. Compared to BCG infection alone, co-infected macrophages exhibited additive expression of genes with known host-protective roles against M. tuberculosis. Conversely, co-infection with BCG suppressed adenovirus-induced type I IFN signaling and diminished the production of IFN-stimulated genes compared to adenovirus infection alone. Together, these findings reveal a complex regulatory interplay during adenovirus and BCG co-infection. While BCG partially restricts adenoviral IFN induction, the co-infection still drives an enhanced host-protective gene profile, suggesting that adenoviral vectors could serve as a viable platform to modulate innate immunity and improve BCG vaccine efficacy. IMPORTANCETuberculosis (TB) remains the leading cause of death by a single infectious organism with approximately 1.25 million deaths annually. M. bovis BCG remains the only approved vaccine for TB; however, its efficacy against the contagious and most common pulmonary form of the disease is limited. There have been numerous attempts to improve BCG efficacy, but these approaches have not resulted in any clinically approved vaccine. We propose that BCG combined with a replication-deficient adenovirus presents a way to bolster vaccine-conferred protection as the combination may elicit a robust innate immune response and drive a more protective T cell response. Moreover, BCG and replication-deficient adenoviruses have well-assessed safety profiles and decades of studies regarding their use in patients. The significance of our work is in leveraging their complementary immunology to function as a combined vaccine platform. This approach presents a novel and clinically feasible approach to improve the BCG vaccine.

Abstract Background: The lack of effective biomarkers and therapeutic targets to overcome radioresistance in cervical cancer remains a major clinical challenge. Tumor necrosis factor receptor-associated factor 6 (TRAF6), an E3 ubiquitin ligase pivotal in immune and inflammatory signaling, has been implicated in various malignancies. However, its role in radioresistance in cervical cancer remains unclear. Methods: TRAF6 expression was evaluated in cervical cancer tissues from 162 patients who underwent postoperative radiotherapy at our institution and in 304 cases from the TCGA-CESC cohort. The prognostic significance of TRAF6 was assessed using Kaplan-Meier and Cox regression analyses. A nomogram integrating TRAF6 expression with clinicopathological factors was constructed to predict overall survival (OS) and progression-free survival (PFS). The functional role of TRAF6 in malignant phenotypes and radiosensitivity was investigated using shRNA-mediated knockdown in HeLa and C33A cervical cancer cells. Immune cell infiltration patterns associated with TRAF6 expression were analyzed using ssGSEA and xCELL algorithms based on TCGA data. Results: TRAF6 expression was significantly elevated in cervical cancer tissues compared with adjacent normal tissues (70.99% vs. control, P < 0.001) and was higher in radioresistant than in radiosensitive patients (P < 0.001). High TRAF6 expression was associated with shorter OS (HR = 18.73, P = 0.004) and PFS (HR = 8.44, P < 0.001) and was identified as an independent risk factor for radiotherapy resistance (OR = 8.44, P < 0.001). The TRAF6-integrated nomogram demonstrated good predictive accuracy for OS (C-index = 0.7351) and PFS (C-index = 0.7444). TRAF6 knockdown in cervical cancer cells significantly suppressed proliferation, migration, and invasion, while substantially enhancing radiosensitivity of tumor cells. Functional enrichment analysis revealed that TRAF6-related genes were enriched in autophagy, mitophagy, and HPV infection pathways. Immune cell infiltration analysis showed that TRAF6 expression correlated with distinct immune cell profiles, characterized by enrichment of activated dendritic cells, M1 macrophages, and regulatory T cells, alongside depletion of cytotoxic effectors such as CD8+ T cells and {gamma}{delta} T cells. Conclusions: TRAF6 could be a prognostic biomarker associated with poor outcomes and indicator of radiotherapy resistance in cervical cancer, TRAF6 represents a potential therapeutic target for overcoming radioresistance in cervical cancer.

BackgroundBevacizumab resistance severely limits long-term efficacy in metastatic colorectal cancer (CRC). This study aimed to develop and validate a bevacizumab resistance-associated gene signature for prognosis prediction and immune microenvironment characterization in CRC. MethodsTwo GEO datasets (GSE19862, GSE86582) with bevacizumab response data and TCGA-COAD/READ RNA-seq data were analyzed. Overlapping differentially expressed genes (DEGs) linked to both CRC progression and bevacizumab resistance were identified. An 8-gene signature (AXIN2, PSORS1C1, KRT74, SLC2A3, STIL, IL33, GALNT6, HSD11B2) was constructed via univariate Cox and LASSO-Cox regression. ResultsIn the TCGA cohort, high-risk patients had shorter overall survival (OS; log-rank P < 0.0001). Time-dependent ROC yielded 1-year AUC = 0.638, 3-year AUC = 0.657, and 5-year AUC = 0.757. Multivariate Cox regression confirmed the risk score as an independent prognostic factor. External validation in GSE39582 (optimal cutoff = -1.49) replicated these findings: high-risk patients had inferior OS (P = 0.0016) with acceptable 1/3/5-year AUCs and retained independent prognostic value (HR = 1.634, P = 0.00415). CIBERSORT and ESTIMATE analyses showed that the high-risk group was characterized by increased M2 macrophages and neutrophils, higher immune and stromal scores, and reduced activated memory CD4+ T cells, monocytes, and activated dendritic cells (all P < 0.05). GSEA highlighted enrichment of TNF-/NF-{kappa}B, IL-6/JAK/STAT3, and immune checkpoint pathways in the high-risk group. AXIN2 (HR = 0.829, P = 0.032) was an independent protective factor, while PSORS1C1 (HR = 1.356, P = 0.048) was an independent risk factor. ConclusionThe 8-gene bevacizumab resistance signature robustly predicts prognosis and reflects an immunosuppressive microenvironment closely linked to bevacizumab failure in CRC. These findings provide novel insights into immune-mediated resistance and support clinical risk stratification.

An autocrine pro-adhesive/pro-contractile signaling loop, through the mechanosensitive transcriptional cofactor YAP, promotes fibrosis. The CCN family of matricellular proteins modify adhesive signaling. Of these, CCN3 is antifibrotic. We show that BLR-200, a CCN3-derived peptide, has anti-fibrotic properties in the bleomycin-induced model of scleroderma skin fibrosis. In vitro, BLR-200 delayed, but did not abolish, fibroblast adhesion to collagen and nuclear YAP localization. In vivo, BLR-200 prevented/treated bleomycin-induced skin fibrosis, and reduced bleomycin-induced expression of profibrotic genes including alpha-smooth muscle actin, CCN1 and CCN2. Lineage tracing and scRNA-seq analyses revealed that the myofibroblasts in this model were quantitatively derived from collagen-lineage Pi16+/Col15+ve fibroblasts. BLR-200 prevented myofibroblast differentiation in this model and trajectory of fibroblasts toward a Sfrp2-positive subset, a cell type associated with poor clinical outcome. BLR-200 impairs YAP activation in vitro and appearance of translationally-relevant fibroblast subtypes in vivo and is a novel anti-fibrotic agent for SSc skin fibrosis.

Background and AimsThe incidence of hepatocellular carcinoma (HCC) is increasingly driven by metabolic risk factors, including obesity and iron overload. Although high-fat and high-iron diets independently promote hepatocarcinogenesis, their shared and distinct molecular effects remain unclear. We sought to define how dietary fat and iron differentially shape HCC development. ApproachMale C3HeB/FeJ mice were exposed to long-term high-fat (HFD), high-iron (HID), or combined (HFD+HID) diets for 16.5 months. Tumor burden, hepatic iron distribution, mTOR signaling, oxidized phospholipid (OxPL) accumulation, and transcriptomic alterations across normal, adjacent non-tumor, and tumor liver tissues were analyzed using biochemical, histological, and RNA sequencing approaches. ResultsAll diets induced HCC with comparable tumor burden. HID increased iron levels in non-tumor liver tissue but resulted in relative iron depletion within tumors, indicating tumor-specific iron utilization. Tumors from all diet groups showed robust mTOR activation and increased OxPL accumulation, with stronger oxidative stress signatures in HFD and HFD+HID tumors. Transcriptomic analyses revealed conserved oncogenic programs alongside diet-specific signatures, with HFD exerting a dominant effect on metabolic reprogramming and gene dysregulation, whereas HID preferentially enhanced immune and inflammatory signaling. Progressive, monotonic changes in gene expression were observed across disease stages. Cross-species analyses linked diet-induced mouse tumors to immunologically "hot" human HCC subtypes. ConclusionsDietary fat and iron promote HCC through overlapping yet distinct molecular pathways, highlighting metabolic and immune mechanisms as key targets in diet-associated liver cancer.

Multiplex staining is a technique that allows the identification of cell types within a single tissue section by simultaneously detecting multiple molecular markers. Generally, multiplex staining is performed using several combinations of probes, including specific antibodies, nucleic acid probes, and lectins. Here, a novel multiplex staining strategy that relies exclusively on lectin probes that target glycans is presented. Glycans have a vast variety of structural forms that vary depending on cell type-specific modifications. Furthermore, an enormous number of glycan-binding molecules, collectively known as lectins, exist in the biological world. Each lectin displays specificity for a particular glycan motif while maintaining broad affinity. Although lectin-based cell staining has been used in various applications, the partial and limited specificity of lectins has hindered the use of glycan-targeted multiplex staining with lectins. In addition, lectin probes have largely been avoided for cell-type identification because of the absence of strict cell-type-specific glycans. Here, a novel staining method, Glycan Painting, is introduced. Rather than viewing the partial specificity of lectins and the broad, non-cell-type-specific distribution of glycans as drawbacks, this approach turns these features into advantages by generating distinct color patterns that comprehensively visualize cell-type-specific glycan combinations and enable full-color imaging of tissues.

Purpose: Pathogenic or likely pathogenic (P/LP) variants are increasingly identified in genes more commonly associated with adult-onset cancer predisposition, but their prevalence and relevance to children who present with cancer remain unclear. Methods: We retrospectively analyzed 1,280 consecutive pediatric patients with cancer who underwent clinical germline sequencing, using a virtual panel, from 2021 to 2024. Genes with P/LP variants were categorized as aoCPG or pediatric-onset cancer predisposition genes (poCPG) according to cancer risk before age 18 years and pediatric surveillance recommendations. Variant relevance was adjudicated using tumor diagnosis/histopathology, immunohistochemistry, and tumor molecular features and classified as primary, secondary, or indeterminate. Results: Among 1,280 patients, 197 (15.4%) harbored 211 P/LP variants across 54 genes. Sixty-six variants (31.3%) occurred in aoCPG, 87 (41.2%) in poCPG, and 58 (27.5%) were heterozygous variants in autosomal recessive genes. Among adult-onset variants, 7 (10.6%) were primary, 54 (81.8%) secondary, and 5 (7.6%) indeterminate. Among pediatric-onset variants, 77 (88.5%) were primary and 10 (11.5%) secondary. Six patients (3 adult-onset variants; 3 pediatric-onset variants) received targeted therapy informed by germline/somatic sequencing results. Conclusion: In pediatric oncology, most variants in aoCPG are secondary rather than tumor-related findings. Tumor-informed interpretation, beyond variant classification, may improve reporting, counseling, and therapeutic decision-making

Background: Non-invasive diagnosis, reliable recurrence surveillance remain critical unmet needs in gliomas. Glioma induces profound systemic immune alterations despite its anatomical confinement to the central nervous system. Circulating immune cells, particularly monocytes, are key mediators of tumor-host crosstalk and may retain tumor-induced transcriptional imprints. However, their potential clinical utility as blood-based biomarkers for detection and monitoring, remain largely unexplored. Methods and findings: In this study, we performed integrated single-cell RNA sequencing of blood immune cells and demonstrated that circulating CD14+ monocytes are significantly expanded in glioma patients, exhibiting features of differentiation arrest and increased transcriptional plasticity. These cells harbor glioma-specific molecular signatures distinct from those observed in healthy controls and patients with other tumors. Leveraging these findings, we developed an ensemble machine learning diagnostic model based on transcriptomic profiles of circulating CD14+ monocytes (training cohort, n=107), which achieved a mean area under the receiver operating characteristic curve (AUC) of 0.971 during cross-validation. In an independent cohort of 567 participants, the model maintained high diagnostic accuracy, yielding an AUC of 0.877 for distinguishing glioma from controls and other tumors. And it achieved a recurrence detection AUC of 0.969 in 51 postoperative samples. Moreover, in a prospective follow-up study involving 30 glioma patients, lower model-derived scores of postoperation were significantly associated with prolonged progression-free survival (log-rank test, P=0.043), supporting its prognostic utility. Conclusion: We demonstrate circulating CD14+ monocytes undergo glioma-specific transcriptional reprogramming, generating systemic tumor-associated signal captured via transcriptomic profiling. This blood-based diagnostic model provides non-invasive, scalable approach for glioma detection, recurrence surveillance, outcome prediction.

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

Background Cancer treatment response is highly variable, even among patients with the same tumor type and treatment. Exceptional responders (ERs), who are individuals who experience unusually favorable outcomes, provide critical insights into the biological factors driving treatment success. While prior studies have highlighted the role of somatic changes, the contribution of germline rare variants remains underexplored. This study aimed to uncover the genetic underpinnings of exceptional responses by identifying rare, non-silent and predicted deleterious germline mutations enriched among ERs compared to typical cancer patients. Methods The Network of Enigmatic Exceptional Responders (NEER) project collected clinical and germline whole-genome sequencing (WGS) data from 53 ERs. After quality control procedures and ancestry background checks, 51 ERs were left for final analysis. While non-silent mutations were identified based on allele frequencies and mutation types, multiple pathogenicity predictors were applied for predicted deleterious variants. These were compared to a harmonized and comparable subset from the Pan-Cancer Analysis of Whole Genomes (PCAWG) cohort (n=414) using Fisher's exact tests. Kaplan-Meier survival analysis applied to evaluate prognostic associations in PCAWG patients. Additionally, Fisher's exact tests were conducted stratified by cancer type and treatment regimen to identify potential associations between rare germline variants and therapeutic responses. Results Variants in immune-related genes such as CCL26 and GPRC5D were prevalent, suggesting enhanced immune regulation among ERs. Fourteen genes with non-silent and eight with predicted deleterious mutations showed significantly different frequencies between NEER and PCAWG cohorts (FDR < 0.05). IRX3 emerged as a protective gene enriched in ERs, whereas OR6B2 was associated with poor survival in PCAWG lung cancer patients. Moreover, rare non-silent germline variants in drug target genes were enriched among ERs treated with cisplatin and doxorubicin, implicating altered DNA repair and drug-binding mechanisms in their remarkable outcomes. Conclusions This study reveals a distinctive germline mutation landscape in exceptional cancer responders, marked by immune-related and drug-target-associated variants that may enhance therapy response and prolong survival. The findings highlight potential novel prognostic biomarkers, such as IRX3 and OR6B2, providing a foundation for developing personalized cancer treatments informed by rare genetic variation.

The ability to generate functional B cells from human pluripotent stem cells (hPSCs) would open new opportunities to develop novel B cell-based therapies to treat a range of human diseases and disorders. Towards this goal, we established a protocol that promotes the efficient development of B lineage cells from definitive hematopoietic progenitors generated from different hPSC lines. Flow cytometric and multi-omic scRNA-seq analyses revealed that B cell development from hPSCs transitions through the well-established pro-B, pre-B and naive B cell stages, accurately recapitulating B lymphopoiesis in the human adult bone marrow. Importantly, the naive B cells generated with this approach could be induced to mature into plasma cells that secrete antibodies and undergo class switching. Analyses of signaling pathways that regulate B lymphopoiesis in these cultures uncovered a potent inhibitory effect of IL-7 on functional IgH rearrangement, resulting in the development of abnormal cells that failed to undergo pre-B cell maturation. Finally, analysis of the different hPSC-derived hematopoietic programs revealed that both definitive and yolk sac progenitors display B cell potential, indicating that there are distinct developmental sources of human B lineage cells. Taken together, these findings demonstrate the efficient generation of B cells from hPSCs and, in doing so, provide a system for further investigating the earliest stages of human B lymphopoiesis and a source of appropriately staged plasma cells for future therapeutic applications.

ContextImmunotherapy based on immune checkpoint inhibitors (ICI) revolutionized the treatment of triple-negative (TN) breast carcinomas (BC), but remains more challenging in HR+/HER2- BCs. Because invasive lobular carcinomas (ILC) generally exhibit low immune infiltration, ICIs were largely overlooked in this pathological type. The only clinical trial of ICIs dedicated to ILCs showed disappointing results, notably in HR+/HER2- cases. The immune landscape of HR+/HER2- ILCs has been poorly described. High level of tumor-infiltrating lymphocytes (TIL) was associated with worse prognosis in HR+/HER2- ILCs. A better characterization of the immune landscape of HR+/HER2- ILCs could clarify the poor efficiency of ICIs and the negative prognostic value of TILs, and reveal complementary targets able to increase immunotherapy efficiency. MethodWe comprehensively characterized the immune landscape of HR+/HER2- ILCs, comparatively to HR+/HER2- invasive ductal carcinomas (IDC), by applying multi-omics and multi-scale analysis (gene expression at the bulk and single-cell levels, and protein-based spatial analysis) to clinical samples. ResultsWhile the overall level of immune infiltration was comparable between both pathological types, the quality of immune infiltrate differed markedly. Comparatively to HR+/HER2- IDCs, HR+/HER2- ILCs were enriched in immune cells and tertiary lymphoid structures with anti-tumor potential, presented more spatial proximity between cancer cells and CD8+ cytotoxic T cells, and stronger theorical vulnerability to ICIs. However, in HR+/HER2- ILCs, anti-tumor response was defective; CD8+ cytotoxic T cells failed to fully unleash their cytotoxic function and CD4+ helper T cells evidenced a pro-tumoral and naive phenotype. Furthermore, antigen-presenting compartment was defective, altogether embedded in a stronger immunosuppressive environment, enriched in immunoregulatory cancer-associated fibroblasts (iCAF). ConclusionThis study contributes to explain the lesser efficiency of PD-1/PD-L1-based ICIs in HR+/HER2-ILCs by comparison with HR+/HER2- IDCs, by shedding light on a complex ecosystem where tumor cells shape a distinctive stroma that contribute to prevent anti-tumor immune response activation. Altogether, our findings further support the rationale for combining iCAF-targeting strategy with an ad hoc immunotherapy (such as an anti-VTCN1/B7-H4 antibody-drug conjugates for example). Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=150 SRC="FIGDIR/small/728418v1_ufig1.gif" ALT="Figure 1"> View larger version (26K): org.highwire.dtl.DTLVardef@c62294org.highwire.dtl.DTLVardef@86392org.highwire.dtl.DTLVardef@c10748org.highwire.dtl.DTLVardef@c543da_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_ST_ABSWHAT IS ALREADY KNOWN ON THIS TOPICC_ST_ABSO_LIImmune cells infiltrate both HR+/HER2- IDC and HR+/HER2- ILC tumors, but current ICIs are less effective in HR+/HER2- ILCs than HR+/HER2- IDCs. C_LI WHAT THIS STUDY ADDSO_LIThe anti-tumor immune response is mobilized but not effective in HR+/HER2- ILCs. C_LIO_LIA complex ecosystem - composed of immunoregulatory cancer-associated fibroblasts, high levels of TGFa, prostaglandin, acidosis, and a lack of antigen-presenting cells - prevents anti-tumor CD8+ cytotoxic T cell activation in HR+/HER2- ILCs. C_LI HOW THIS STUDY MIGHT AFFECT RESEARCH, PRACTICE, OR POLICYO_LITargeting the PD-1/PD-L1 axis is not the appropriate therapeutic strategy for HR+/HER2- ILCs. A more complex approach should be considered, notably those combining other immune-based strategies and iCAF targeting, which may offer a better chance to eradicate HR+/HER2- ILC tumor cells. C_LI

Merkel cell carcinoma (MCC) is a rare and aggressive neuroendocrine skin cancer that frequently carries integrated Merkel cell polyomavirus DNA and expresses oncogenic viral small T antigen (sTAg) and truncated large T antigen (tLTAg). We previously reported a mouse model of MCC with skin-targeted expression of sTAg, tLTAg, and the Merkel cell transcription factor ATOH1, combined with deletion of Trp53. Here, we optimized this model to achieve 100% tumor penetrance with lymph node metastases, established four mouse MCC cell lines, and selected one line, mMCC2, for pilot preclinical trials. In immunocompetent C57BL/6J mice, mMCC2 cells reliably produce MCCs and lymph node metastases following subcutaneous or intradermal (orthotopic) injection, and liver and lung metastases after tail vein injection. Mouse MCC allografts resemble parental tumors histologically and express a full complement of MCC differentiation markers. Treatment of allografted mice with anti-PD-1 resulted in variable inhibition of tumor growth. In contrast, treatment with lysine-specific histone Wdemethylase 1 (LSD1) inhibitors, with or without anti-PD-1, led to consistently lower tumor volumes by 5.7-fold in both groups (P < 0.0001) and smaller or undetectable lymph node metastases. Growth-inhibited tumors in all groups showed a marked reduction in proliferating tumor cells and increased infiltration by F4/80+ macrophages and CD8+ T cells. These findings support a role for immune-cell recruitment in treatment response and underscore the importance of immunocompetent preclinical models, even in studies using targeted therapies. This unique virus-positive MCC allograft model, which produces local tumors as well as regional and distant metastases in immunocompetent hosts, provides a critical platform for preclinical evaluation of new therapeutic strategies and sets the stage for much-needed translational studies to inform future clinical trials.

IntroductionResistance to immunotherapy remains a major clinical challenge in TP53-mutant head and neck squamous cell carcinoma (HNSCC), a disease subset characterized by immune exclusion, high recurrence, and poor outcomes. Given the constitutive activation of PI3K/AKT/mTOR signaling in TP53-mutant HNSCC and its role in disease progression, we investigated whether the mTOR inhibition (mTORi) could overcome immune resistance and improve outcomes. MethodsWe evaluated the effects of mTOR inhibitor everolimus in TP53-mutant, anti-PD-1-resistant syngeneic HNSCC cell lines and syngeneic tumor models. Tumor microenvironment (TME) changes, including immune cell infiltration, immune checkpoint expression, and key pathways associated with immune suppression and angiogenesis were assessed to define the mechanisms underlying TME remodeling. ResultsEverolimus significantly suppressed tumor growth in syngeneic HNSCC models. At the cellular level, everolimus significantly increased intratumoral CD8+ T cell and dendritic cell (DC) infiltration while reducing the accumulation of regulatory T cells (Tregs). Mechanistically, everolimus induced a cytokine/chemokine response, marked by increased TNF-/CXCL10 expression, leading to enhanced immune infiltration. Everolimus also inhibited the HIF-1/VEGFA angiogenic axis, a central driver of immune exclusion and myeloid-derived suppressor cell (MDSC) recruitment. Furthermore, everolimus treatment attenuated PD-1/PD-L1 signaling by reducing PD-1 and PD-L1 expression, respectively, in T cells and tumor cells, thereby restoring T-cell cytotoxic competence. DiscussionThese findings demonstrate that mTORi with everolimus reverses multiple mechanisms of immune resistance in TP53-mutant HNSCC by promoting immune cell recruitment, suppressing immunosuppressive pathways, and enhancing anti-tumor T cell activity. Collectively, these results support mTORi as a mechanistically rational strategy for reprogramming immune resistance in TP53-mutant HNSCC and provide a strong preclinical rationale for combining everolimus with immune therapy in patients who are likely to fail immunotherapy.

Keloids are fibroproliferative skin disorders arising following dermal injury that extend beyond the original wound margins. Their pathogenesis remains poorly understood, and current treatments are associated with high recurrence rates. Identifying transcriptomic biomarkers that distinguish keloids from other skin and scar phenotypes may provide insight into disease mechanisms and facilitate the development of targeted therapeutic approaches. However, previous transcriptomic studies have often been limited by small sample sizes, pairwise comparisons between tissue classes, heterogeneous data-integration strategies, and a reliance on conventional differential gene expression (DGE) analysis. Here, we employed a multi-stage machine learning (ML) workflow for robust keloid biomarker discovery using transcriptomic datasets derived from both bulk RNA sequencing and single-cell RNA sequencing (scRNA-seq). We assembled and harmonized, to the best of our knowledge, the largest curated cross-study keloid transcriptomic cohort currently available, comprising 81 samples from 13 independent studies spanning four clinically relevant tissue classes: normal skin, normotrophic scar, hypertrophic scar, and keloid scar. Through study-aware cross-validation, feature selection, partition-stability analysis, and bootstrap validation across multiple ML classifiers, we identified a panel of eight highly consistent biomarkers capable of distinguishing keloid from non-keloid samples. These biomarkers were associated with dysregulation of extracellular matrix homeostasis, fibrosis-resolution pathways, vascular remodelling, and metabolic reprogramming. Comparison with conventional DGE analysis demonstrated substantial agreement while also highlighting important differences between the two approaches. In particular, FASN was consistently identified by the ML workflow as an upregulated discriminatory biomarker despite exhibiting weak, non-significant differential expression in the DGE analysis. Cell-type-specific analysis further supported this finding, revealing significant FASN upregulation in fibroblast and vascular endothelial populations. These results demonstrate that ML and DGE capture complementary aspects of transcriptomic variation. This study provides a robust strategy for cross-study transcriptomic biomarker discovery and identifies candidate genes and pathways for future mechanistic and therapeutic investigation in keloids. 1 Author SummaryKeloids are abnormal scars that continue to grow beyond the original wound and can be difficult to treat because they frequently recur after therapy. Although many studies have investigated the biology of keloids, the molecular mechanisms that distinguish them from other scar types remain incompletely understood. Identifying biomarkers involved in keloid formation may help inform improved treatment strategies. Previous transcriptomic studies have often been limited by small sample sizes and inconsistent analytical approaches. In this study, we combined gene-expression data from multiple independent studies to create, to the best of our knowledge, the largest cross-study transcriptomic collection available for keloid analysis. We then applied several machine learning approaches to identify genes that consistently distinguished keloids from other skin and scar phenotypes. The identified biomarkers were associated with extracellular matrix remodeling, fibrosis, vascular function, and cellular metabolism. One gene involved in fatty-acid synthesis, FASN, was repeatedly identified by the machine learning analyses despite being overlooked by conventional gene-expression methods. Additional single-cell analyses confirmed elevated FASN expression in specific cell populations within keloid tissue. More broadly, this work provides a strategy for discovering robust biomarkers from heterogeneous biological datasets and identifies molecular targets for future studies of keloid disease.