Neutrophil diversity and plasticity in tumour progression and therapy

Fusobacterium nucleatum-driven CX3CR1+ PD-L1+ phagocytes route to tumor tissues and reshape tumor microenvironment

The intracellular bacterium Fusobacterium nucleatum (Fn) mediates tumorigenesis and progression in colorectal cancer (CRC). However, the origin of intratumoral Fn and the role of Fn-infected immunocytes in the tumor microenvironment remain unclear. Here, we observed that Fn-infected neutrophils/macrophages (PMNs/MΦs), especially PMNs, accumulate in tumor tissues and fecal Fn abundance correlates positively with an abundance of blood PD-L1+ PMNs in CRC patients. Moreover, Fn accumulates in tumor tissues of tumor-bearing mice via intragingival infection and intravenous injection. Mechanistically, Fn can survive inside PMNs by reducing intracellular ROS levels and producing H2S. Specifically, the lysozyme inhibitor Fn1792 as a novel virulence factor of Fn suppressed apoptosis of phagocytes by inducing CX3CR1 expression. Furthermore, Fn-driven CX3CR1+PD-L1+ phagocytes transfer intracellular Fn to tumor cells, which recruit PMNs/MΦs through the CXCL2/8-CXCR2 and CCL5/CCR5 axes. Consequently, CX3CR1+PD-L1+ PMNs infiltration promotes CRC metastasis and weakens the efficacy of immunotherapy. Treatment with the doxycycline eradicated intracellular Fn, thereby reducing the CX3CR1+PD-L1+ PMNs populations and slowing Fn-promoted tumor growth and metastasis in mice. These results suggest phagocytes as Fn-presenting cells use mutualistic strategies to home to tumor tissues and induce immunosuppression, and treatment with ROS-enhanced antibiotics can inhibit Fn-positive tumor progression.

Clca1 deficiency exacerbates colitis susceptibility via impairment of mucus barrier integrity and gut microbiota homeostasis

The intestinal mucus barrier has emerged as a promising therapeutic target for inflammatory bowel disease. Understanding its regulatory mechanisms is critical for elucidating ulcerative colitis (UC) pathogenesis, improving diagnostics, guiding treatments, and preventing relapse. Chloride Channel Accessory 1 (Clca1), a constituent of the mucus layer, remains understudied in colitis. Here, we investigated Clca1's role in mucosal immunity and intestinal homeostasis using experimental colitis models. Clca1-deficient (Clca1-/-) mice displayed compromised mucus layer integrity, reduced neutrophil infiltration, and gut microbiota dysbiosis. Notably, Clca1-/- mice exhibited exacerbated colitis severity following dextran sulfate sodium (DSS) challenge, accompanied by a diminished goblet cell populations. Fecal microbiota transplantation (FMT) studies revealed that gut microbiota critically modulates divergent phenotypic outcomes between genotypes. Our findings establish Clca1 as a multifunctional regulator of mucus barrier integrity through mechanisms involving goblet cell maintenance, neutrophil-mediated immunity, and host-microbiota crosstalk. These results advance the understanding of UC pathogenesis and identify Clca1-associated pathways as potential targets for barrier restoration therapies.

The role of innate immune cells in modulating vascular dynamics in skin malignancies

A developing tumor relies heavily on blood vessels to supply oxygen and nutrients. As a result, angiogenesis, the formation of new blood vessels, supports tumor growth and progression. Similarly, lymphangiogenesis, the formation of new lymphatic vessels, plays a critical role in metastatic dissemination by providing pathways for malignant cells to spread. The tumor microenvironment is crucial for establishing and maintaining these vascular networks, with innate immune cells playing a key regulatory role. Notably, immune cells are specifically enriched in barrier tissues, such as the skin, emphasizing their importance in skin malignancies. Therefore, understanding their role in regulating angiogenesis and lymphangiogenesis is essential for developing novel therapeutic strategies. This review article explores how innate immune cells influence tumor vasculature and highlights the therapeutic potential that may arise from this knowledge.

A DNA-based nanorobot for targeting, hitchhiking, and regulating neutrophils to enhance sepsis therapy

Targeted regulation of neutrophils is an effective approach for treating neutrophil-driven inflammatory diseases, but challenges remain in minimizing off-target effects and extending drug half-life. A DNA-based nanorobot was developed to target neutrophils by using an N-acetyl Pro-Gly-Pro (Ac-PGP) peptide to specifically bind to the C-X-C motif of chemokine receptor 2 (CXCR2) on neutrophil membranes. This robot (a tetrahedral framework nucleic acid modified with Ac-PGP, APT) identified and hitchhiked neutrophils to accumulate at inflammatory sites and prolong its half-lives, whilst also was internalized to influence the neutrophil cell cycle and maturation process to regulate oxidative stress, inflammation, migration, and recruitment in both in vivo and in vitro inflammation experiments. Consequently, the tissue damage caused by sepsis was greatly reduced. This novel neutrophil-based nanorobot highlights the high precision of targeting and regulating neutrophils, and presents a potential strategy for treating multiple neutrophil-driven diseases.

Neutrophils in BCR::ABL1 negative MPN: Contributors or bystanders of fibrosis?

BCR::ABL1 negative myeloproliferative neoplasms (MPNs) are a heterogenous group of disorders characterized by clonal proliferation of hematopoietic stem and progenitor cells (HSPCs) within the bone marrow. Although the identification of somatic key driver mutations significantly increased both understanding and diagnostic accuracy of MPNs, many questions about the exact pathophysiology remain unanswered. Increased neutrophil count at diagnosis is a well-recognized predictor of worse disease evolution and survival, nonetheless the exact role of neutrophilic granulocytes within MPN pathophysiology is almost unexplored. As the majority of these cells are residing within the bone marrow, they represent a non-negligible entity within the bone marrow niche and its homeostasis. This review describes how neutrophils might contribute to the development of the inflammatory bone marrow niche, and hereby also fibrosis, associated with MPNs. The versatile functions and effects in different contexts emphasize the necessity for future research oriented to bone marrow in addition to peripheral blood.

TRAIL induces cytokine production via the NFkB2 pathway promoting neutrophil chemotaxis and neutrophil-mediated immune-suppression in triple negative breast cancer cells

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a potential cancer therapeutic that induces apoptosis in cancer cells while sparing the non-malignant cells in preclinical models. However, its efficacy in clinical trials has been limited, suggesting unknown mechanisms modulating TRAIL activity in patients. We hypothesized that TRAIL treatment elicits transcriptional changes in triple negative breast cancer (TNBC) cells that alter the immune milieu. RNAseq analysis of MDA-MB-231 cells along with validation in additional cell lines demonstrated that TRAIL induced cytokines such as CXCLs 1, 2, 3, 8,11 and IL-6, which are known to modify neutrophil function. Mechanistically, TRAIL dependent induction of the cytokines was predominantly mediated by death receptor 5, caspase-8 and the non-canonical NFKB2 pathway. These cytokines produced by TRAIL-treated TNBC cells enhanced chemotaxis of normal human donor isolated neutrophils. Using TNBC xenograft models, TRAIL induced activation of NFkB2 pathway, cytokine production and increased neutrophil recruitment into the tumors. Moreover, preincubation of neutrophils in supernatants from TRAIL-treated TNBC cells significantly impaired neutrophil function as measured by reduced respiratory burst and cytotoxic effect against TNBC cells. Transcriptomic analysis of neutrophils incubated with either TRAIL alone or supernatant of TRAIL-treated TNBC cells revealed increased expression of inflammatory cytokines, immune modulatory genes, immune checkpoint genes, and genes implicated in delayed neutrophil apoptosis. Functional studies showed that these neutrophils suppress T cell proliferation and augment Treg suppressive phenotype. Collectively, our study demonstrates a novel role of TRAIL-induced NFKB2-dependent cytokine production that promotes neutrophil chemotaxis and neutrophil-mediated immune suppression.

Modeling large cell neuroendocrine carcinoma of the lung for molecular, therapeutic and microenvironmental inferences: current knowledge and future perspectives

INTRODUCTION

Large cell neuroendocrine carcinoma (LCNEC) of the lung is a high-grade non-small cell carcinoma featuring neuroendocrine morphology and neuroendocrine markers. Despite being credited since decades as an independent tumor entity, it continues to represent a diagnostic and therapeutic challenge probably because makes up a heterogeneous melting pot of genetic and epigenetic alterations closely intertwined with host microenvironment.

AREAS COVERED

LCNEC of the lung was untangled according to three converging outlooks: (i) diagnostic criteria and molecular alterations as conveyors of pathogenetic diversification; (ii) microenvironmental changes, including immune system, as culprits behind tumor development; and (iii) available clinical trials, including immune-oncology studies as clinical decision-making drivers.

EXPERT OPINION

LCNEC of the lung unveils different developmental trajectories, which may account for troubles in diagnosis and clinical decision-making but, at the same time, offer a rationale for personalized targeted treatments or immunotherapy in patient subsets. Currently, the question is fascinating: are we actually ready for a radical route change in the understanding of LCNEC? The answer is still open, but future studies will need to frame LCNEC in its own overarching context among lung cancers according to a holistic vision, which does not limit us to its perception as being 'just one tumor.'

Radiomic Model Associated with Tumor Microenvironment Predicts Immunotherapy Response and Prognosis in Patients with Locoregionally Advanced Nasopharyngeal Carcinoma

Background: No robust biomarkers have been identified to predict the efficacy of programmed cell death protein 1 (PD-1) inhibitors in patients with locoregionally advanced nasopharyngeal carcinoma (LANPC). We aimed to develop radiomic models using pre-immunotherapy MRI to predict the response to PD-1 inhibitors and the patient prognosis. Methods: This study included 246 LANPC patients (training cohort, n = 117; external test cohort, n = 129) from 10 centers. The best-performing machine learning classifier was employed to create the radiomic models. A combined model was constructed by integrating clinical and radiomic data. A radiomic interpretability study was performed with whole slide images (WSIs) stained with hematoxylin and eosin (H&E) and immunohistochemistry (IHC). A total of 150 patient-level nuclear morphological features (NMFs) and 12 cell spatial distribution features (CSDFs) were extracted from WSIs. The correlation between the radiomic and pathological features was assessed using Spearman correlation analysis. Results: The radiomic model outperformed the clinical and combined models in predicting treatment response (area under the curve: 0.760 vs. 0.559 vs. 0.652). For overall survival estimation, the combined model performed comparably to the radiomic model but outperformed the clinical model (concordance index: 0.858 vs. 0.812 vs. 0.664). Six treatment response-related radiomic features correlated with 50 H&E-derived (146 pairs, |r|= 0.31 to 0.46) and 2 to 26 IHC-derived NMF, particularly for CD45RO (69 pairs, |r|= 0.31 to 0.48), CD8 (84, |r|= 0.30 to 0.59), PD-L1 (73, |r|= 0.32 to 0.48), and CD163 (53, |r| = 0.32 to 0.59). Eight prognostic radiomic features correlated with 11 H&E-derived (16 pairs, |r|= 0.48 to 0.61) and 2 to 31 IHC-derived NMF, particularly for PD-L1 (80 pairs, |r|= 0.44 to 0.64), CD45RO (65, |r|= 0.42 to 0.67), CD19 (35, |r|= 0.44 to 0.58), CD66b (61, |r| = 0.42 to 0.67), and FOXP3 (21, |r| = 0.41 to 0.71). In contrast, fewer CSDFs exhibited correlations with specific radiomic features. Conclusion: The radiomic model and combined model are feasible in predicting immunotherapy response and outcomes in LANPC patients. The radiology-pathology correlation suggests a potential biological basis for the predictive models.

Targeting circulating tumor cell‒neutrophil interactions: nanoengineered strategies for inhibiting cancer metastasis

Metastasis remains the leading cause of cancer-related mortality, with a persistently poor prognosis for metastatic cancer patients despite extensive therapeutic efforts. Circulating tumor cells (CTCs), which detach from primary tumors and enter the bloodstream, can establish distant metastatic sites. These CTCs often form heterotypic clusters with white blood cells, especially neutrophils, through various interaction mechanisms, including intercellular adhesion, cytokine secretion, protease release, and the formation of neutrophil extracellular traps (NETs). These interactions enhance CTCs survival, proliferation, invasion, and transendothelial migration while simultaneously remodeling premetastatic niches and the tumor microenvironment. Consequently, pharmacologically disrupting CTC‒neutrophil crosstalk represents a promising strategy to curb metastatic spread and improve clinical outcomes. Recent breakthroughs in nanotechnology-based drug delivery systems have shown considerable potential in antimetastatic therapies, offering significant advantages over conventional treatments, which are often associated with severe side effects and limited efficacy. This review systematically explores nanoengineered strategies targeting CTC‒neutrophil interactions, addresses the current limitations and outlines future directions for developing clinically translatable nanotherapeutics.

The heterogeneous roles of neutrophils in gastric cancer: scaffold or target?

Gastric cancer (GC) is a significant challenge for global health. Neutrophils, the predominant white blood cells in the innate immune system, are increasingly becoming known as potential contributors to either tumor-promoting or tumor-suppressive activities within different tumor biology settings. This review highlights such dual roles of neutrophils in GC, where complex interactions occur within the tumor microenvironment. Specifically, we focus on the formation and function of neutrophil extracellular traps (NETs), which have emerged as critical players in GC progression. NETs influence key processes such as inflammation, angiogenesis, and metastasis. This review offers a comprehensive analysis of the polarization of neutrophils into two of its distinct subtypes, namely N1 and N2, which exert opposing influences on tumor biology. While N1 neutrophils exert anti-tumor properties, N2 neutrophils are generally regarded as pro-tumor. We uniquely discuss how these subtypes interact with cancer cells, affecting epithelial-mesenchymal transition and immune evasion mechanisms. These interactions change the tumor microenvironment and impact overall GC progression. In addition, we underscore the potential of neutrophils and their associated molecules as biomarkers and therapeutic targets. Specific neutrophil-derived markers and neutrophil-associated signaling pathways, along with their perspectives in personalized medicine that would pave the way for neutrophil-based anti-GC therapy, have been discussed in this review. Through the integration of these perspectives, we aim to guide future research involving neutrophils and their therapeutic implications, thus establishing strategies to precisely and effectively treat GC and improve prognosis.

Neutrophil Spatiotemporal Regulatory Networks: Dual Roles in Tumor Growth Regulation and Metastasis

Neutrophils, accounting for 50-70% of circulating leukocytes, exhibit remarkable plasticity in tumor biology. Depending on tumor type and microenvironmental cues, they can exert either anti-tumor or pro-tumor effects. During tumor initiation, neutrophils exposed to chronic inflammation secrete cytokines and oncogenic microRNAs that promote genomic instability and malignant transformation. In tumor progression, neutrophils adopt context-dependent phenotypes and execute diverse functions, including polarization into anti-tumor (N1) or pro-tumor (N2) subsets; secretion of inflammatory and angiogenic mediators; formation of neutrophil extracellular traps (NETs); production of reactive oxygen and nitrogen species (e.g., H2O2 and nitric oxide); and modulation of immune cell infiltration and function within the tumor microenvironment. During metastasis, neutrophils facilitate cancer dissemination through three principal mechanisms: (1) promoting epithelial-mesenchymal transition (EMT) via inflammatory signaling, adhesion molecule interactions, and lipid metabolic support; (2) establishing pre-metastatic niches by remodeling distant organ stroma through NETs and matrix metalloproteinases; and (3) reactivating dormant tumor cells in response to chronic inflammation, viral infection, or stress hormones. Collectively, neutrophils function as central regulators across all stages of tumor evolution, influencing cancer growth, immune evasion, and metastatic progression. This review aims to provide a comprehensive synthesis of neutrophil-mediated mechanisms in the tumor microenvironment and highlight emerging strategies for neutrophil-targeted cancer therapy.

Tumor-associated neutrophils in breast cancer: an angel or a devil?

Breast cancer is the most common malignant tumor in women, ranking first globally in both incidence and mortality rates among female malignancies, posing a severe threat to women's physical and mental health. Neutrophils are recognized as the first line of host defense against pathogens and exert beneficial effects in the body. However, emerging evidence has demonstrated that tumor-associated neutrophils (TANs) exhibit a dual role in breast cancer progression and prognosis. Therefore, elucidating their molecular mechanisms may provide novel insights for targeted therapies, potentially improving clinical outcomes for breast cancer patients. This review summarizes the interplay between TANs and breast cancer, their underlying mechanisms, and their potential as immunotherapeutic targets.

Unraveling the immune mechanisms and therapeutic targets in lung adenosquamous transformation

Adenocarcinoma-to-squamous cell carcinoma transformation (AST) induces drug resistance in patients with lung adenocarcinoma (LUAD), often resulting in unfavorable clinical outcomes. In recent years, it has been found that alterations in the tumor immune microenvironment (TIME) during adenosquamous carcinoma trans-differentiation also influence the efficacy of immunotherapy. Moreover, the aberrant expression and activation of several driver genes for AST lead to abnormal infiltration and function of immune cell by remodeling the cellular inflammatory phenotype. In this review, we will systematically present the changes in the TIME and molecular regulatory mechanisms during adenosquamous carcinoma differentiation, aiming to gain a better understand of the function of immune cells during this process and the potential value of combining immunotherapy to enhance the treatment of non-small cell lung cancer (NSCLC).

MYO1F in neutrophils is required for the response to immune checkpoint blockade therapy

Tumor-associated neutrophils (TANs) represent a significant barrier to the effectiveness of immune checkpoint blockade (ICB) therapy. A comprehensive understanding of TANs' regulatory mechanisms is therefore essential for predicting ICB efficacy and improving immunotherapy strategies. Our study reveals that MYO1F is selectively downregulated in neutrophils within both human cancers and murine tumor models, showing a negative correlation with ICB response. Mechanistically, MYO1F normally inhibits neutrophil immunosuppression and proliferation by restraining STAT3 activity. However, during tumorigenesis, tumor-derived TGF-β1 disrupts the binding of SPI1 to intron 8 of Myo1f via DNA methylation, thereby suppressing Myo1f transcription. The resultant decrease in MYO1F reprograms neutrophils into an immunosuppressive state through the STAT3-dependent signaling pathways. This immunosuppressive state further contributes to tumor microenvironment (TME) remodeling by inducing CTL exhaustion. These findings establish MYO1F as a critical regulator within TANs, highlighting its significant role in modulating ICB therapy efficacy.

Tumor-infiltrating myeloid cells; mechanisms, functional significance, and targeting in cancer therapy

Tumor-infiltrating myeloid cells (TIMs), which encompass tumor-associated macrophages (TAMs), tumor-associated neutrophils (TANs), myeloid-derived suppressor cells (MDSCs), and tumor-associated dendritic cells (TADCs), are of great importance in tumor microenvironment (TME) and are integral to both pro- and anti-tumor immunity. Nevertheless, the phenotypic heterogeneity and functional plasticity of TIMs have posed challenges in fully understanding their complexity roles within the TME. Emerging evidence suggested that the presence of TIMs is frequently linked to prevention of cancer treatment and improvement of patient outcomes and survival. Given their pivotal function in the TME, TIMs have recently been recognized as critical targets for therapeutic approaches aimed at augmenting immunostimulatory myeloid cell populations while depleting or modifying those that are immunosuppressive. This review will explore the important properties of TIMs related to immunity, angiogenesis, and metastasis. We will also document the latest therapeutic strategies targeting TIMs in preclinical and clinical settings. Our objective is to illustrate the potential of TIMs as immunological targets that may improve the outcomes of existing cancer treatments.

Neutrophil-Mimicking Nanomedicine Eliminates Tumor Intracellular Bacteria and Enhances Chemotherapy on Liver Metastasis of Colorectal Cancer

Fusobacterium nucleatum (Fn) enrichment has been identified in colorectal cancer and its liver metastases. In this study, we found that Fn predominantly accumulated within colorectal cancer cells, correlating with colorectal cancer liver metastasis. Clinically, the administration of high doses of antibiotics and chemotherapeutic agents can disrupt the balance of the host microbiota. To address this clinical challenge, metronidazole (MTI) and oxaliplatin (OXA) are encapsulated within poly (lactic-co-glycolic acid) (PLGA) nanoparticles. Neutrophil membrane vesicles are extracted from murine bone marrow and coated with these nanoparticles (NM@PLGA-MTI-OXA), creating neutrophil-mimetic nanoparticles with dual targeting capabilities for antibacterial and anticancer purposes. The neutrophil membrane coating, compared with free drugs, is found to enhance nanoparticle uptake by tumor cells, facilitating intracellular bacterial elimination and tumor cell death. Further experiments reveal that NM@PLGA-MTI-OXA reverses the Fn-induced epithelial-mesenchymal transition (EMT) in tumor cells during metastasis and remodels the immunosuppressive microenvironment, suppressing colorectal cancer and liver metastasis development while minimizing broad-spectrum damage to the commensal microbiota.

Immunotyping the Tumor Microenvironment Reveals Molecular Heterogeneity for Personalized Immunotherapy in Cancer

The tumor microenvironment (TME) significantly influences cancer prognosis and therapeutic outcomes, yet its composition remains highly heterogeneous, and currently, no highly accessible, high-throughput method exists to define it. To address this complexity, the TMEclassifier, a machine-learning tool that classifies cancers into three distinct subtypes: immune Exclusive (IE), immune Suppressive (IS), and immune Activated (IA), is developed. Bulk RNA sequencing categorizes patient samples by TME subtype, and in vivo mouse model validates TME subtype differences and differential responses to immunotherapy. The IE subtype is marked by high stromal cell abundance, associated with aggressive cancer phenotypes. The IS subtype features myeloid-derived suppressor cell infiltration, intensifying immunosuppression. In contrast, the IA subtype, often linked to EBV/MSI, exhibits robust T-cell presence and improved immunotherapy response. Single-cell RNA sequencing is applied to explore TME cellular heterogeneity, and in vivo experiments demonstrate that targeting IL-1 counteracts immunosuppression of IS subtype and markedly improves its responsiveness to immunotherapy. TMEclassifier predictions are validated in this prospective gastric cancer cohort (TIMES-001) and other diverse cohorts. This classifier could effectively stratify patients, guiding personalized immunotherapeutic strategies to enhance precision and overcome resistance.

Machine learning prediction of perineural invasion in intrahepatic cholangiocarcinoma

OBJECTIVE

Perineural invasion (PNI) significantly influences postoperative recurrence and survival in intrahepatic cholangiocarcinoma (ICC) patients. This study aims to develop and validate an interpretable model that can be used to predict PNI in ICC cases before surgery.

METHODS

Retrospective clinical information was gathered from ICC patients (n = 250) at our hospital, covering the period from January 2012 to January 2022. The patients were randomly assigned to the training group (n = 176, 70.4 %) and validation group (n = 74, 29.6 %). We employed four machine learning algorithms to establish prediction models, each model's performance was assessed via a receiver operating characteristic (ROC) curve. Decision Curve Analysis (DCA) was performed to evaluate the models' risks and benefits. SHapley Additive exPlanations (SHAP) were used to quantify the contributions of model features, providing both global and local interpretations.

RESULTS

Significant differences in tumor size, tumor number, lymph node metastasis, CA199, distant metastasis ratio, HBsAg, PLR, and NLR were observed between the PNI[-] (n = 172, 68.8 %) and PNI[+](n = 78, 31.2 %) groups. The PFS and OS rates in the PNI[-] group were better than those in the PNI[+] group. Based on the evaluation of the validation group, the XGBoost model demonstrated the best predictive performance. SHAP analysis identified tumor number, tumor size, and lymph node metastasis as the top three factors predicting PNI in ICC patients.

CONCLUSION

We developed a reliable predictive model that effectively predicts PNI status in patients with ICC and facilitates personalized clinical decision-making.

Harnessing Exosomes: From Tumor Immune Escape to Therapeutic Innovation in Gastric Cancer Immunotherapy

Gastric cancer ranks fifth among the most prevalent cancers globally, with a dismal prognosis. In recent years, immunotherapy, particularly immune checkpoint inhibitors, has emerged as a glimmer of hope for advanced gastric cancer patients. However, not all patients can benefit from this treatment modality, as the tumor microenvironment significantly influences treatment efficacy. Exosomes, pivotal mediators of intercellular communication, exert intricate and diverse effects in shaping and regulating the tumor microenvironment. This review provides a comprehensive overview of the functional mechanisms of exosomes within the gastric cancer tumor microenvironment. It delves into their biogenesis, functions, and impact on innate and adaptive immune cells (such as dendritic cells, myeloid-derived suppressor cells, and T cells) and cancer-associated fibroblasts. Additionally, the potential applications of exosomes in gastric cancer immunotherapy are explored, including their use as biomarkers to predict responses to immune checkpoint inhibitors, and drug delivery vectors, and in the development of exosome-based vaccines and gene therapy. Notably, this review emphasizes the dual nature of exosomes: they can facilitate tumor immune escape, yet they also serve as promising targets for innovative therapeutic strategies. It also compares potential exosome-based strategies with existing immunotherapies like ICIs and emerging CAR-T cell therapies. Finally, insights into the future of exosomes in precision immunotherapy for gastric cancer are offered, presenting a forward-looking perspective on this emerging field.

Intratumoral Fusobacterium nucleatum Recruits Tumor-Associated Neutrophils to Promote Gastric Cancer Progression and Immune Evasion

Intratumoral microbiota can affect the development and progression of many types of cancer, including gastric cancer. A better understanding of the precise mechanisms by which microbiota support gastric cancer could lead to improved therapeutic approaches. In this study, we investigated the effect of intratumoral microbiota on the tumor immune microenvironment during gastric cancer malignant progression. Analysis of human gastric cancer tissues with 16S rRNA amplicon sequencing revealed that Fusobacterium nucleatum was significantly enriched in gastric cancer tissues with lymph node metastasis and correlated with a poor prognosis. F. nucleatum infection spontaneously induced chronic gastritis and promoted gastric mucosa dysplasia in mice. Furthermore, gastric cancer cells infected with F. nucleatum showed accelerated growth in immunocompetent mice compared with immunodeficient mice. Single-cell RNA sequencing uncovered that F. nucleatum recruited tumor-associated neutrophils (TAN) to reshape the tumor immune microenvironment. Mechanistically, F. nucleatum invaded gastric cancer cells and activated IL17/NF-κB/RelB signaling, inducing TAN recruitment. F. nucleatum also stimulated TAN differentiation into the protumoral subtype and subsequent promotion of PD-L1 expression, further facilitating gastric cancer immune evasion while also enhancing the efficacy of anti-PD-L1 antibody therapy. Together, these data uncover mechanisms by which F. nucleatum affects gastric cancer immune evasion and immunotherapy efficacy, providing insights for developing effective treatment strategies. Significance: Intratumoral F. nucleatum activates NF-κB signaling to facilitate gastric cancer immune evasion by promoting tumor-associated neutrophil recruitment that sensitizes tumors to immune checkpoint blockade therapy.

Unraveling the immunosuppressive microenvironment of glioblastoma and advancements in treatment

Glioblastoma, the most common and aggressive primary brain tumor, remains a significant challenge in oncology due to its immunosuppressive tumor microenvironment (TME). This review summarizes the complex interplay of immune cells and cytokines within the TME, which contribute to immune evasion and tumor progression. We further emphasize the synergistic crosstalk among these components and how it shapes therapeutic vulnerability. Besides, we highlight recent advancements in immunotherapy, including immune checkpoint inhibitors, CAR-T cell therapy, NK cell therapy, oncolytic viruses, and vaccine-based strategies. Despite promising preclinical and clinical results, overcoming the immunosuppressive TME remains a critical hurdle. This review underscores the potential of targeting the TME to enhance therapeutic outcomes in glioblastoma.

Targeting neutrophils for cancer therapy

Neutrophils are among the most abundant immune cell types in the tumour microenvironment and have been associated with poor outcomes across multiple cancer types. Yet despite mounting evidence of their role in tumour progression, therapeutic strategies targeting neutrophils have only recently gained attention and remain limited in scope. This is probably due to the increasing number of distinct neutrophil subtypes identified in cancer and the limited understanding of the mechanisms by which these subsets influence tumour progression and immune evasion. In this Review, we discuss the spectrum of neutrophil subtypes - including those with antitumour activity - and their potential to polarize towards tumour-suppressive phenotypes. We explore the molecular pathways and effector functions by which neutrophils modulate cancer progression, with an emphasis on identifying tractable therapeutic targets. Finally, we examine emerging clinical trials aimed at modulating neutrophil lineages and consider their implications for patient outcomes.

Glycosylation-driven programs coordinate immunoregulatory and pro-angiogenic functions of myeloid-derived suppressor cells

Myeloid-derived suppressor cells (MDSCs) promote tumor progression by suppressing antitumor immunity and inducing angiogenesis; however, the mechanisms linking these processes remain uncertain. Here, we identified a glycosylation-dependent program driven by galectin-1 (GAL1) that imparted both immunoregulatory and pro-angiogenic functions to MDSCs through shared receptor signaling pathways. GAL1 expression was associated with enhanced MDSC phenotypes and poor prognosis in diverse human cancers. Analysis of monocytic and polymorphonuclear MDSCs from tumor-bearing mice revealed niche-specific glycan signatures that selectively regulated GAL1 binding. Through glycosylation-dependent interactions with the CD18-CD11b-CD177 receptor complex and STAT3 signaling, GAL1 simultaneously orchestrated immunosuppressive and pro-angiogenic programs in MDSCs, driving tumor growth in vivo. Myeloid-specific deletion of β-galactoside α(2,6)-sialyltransferase 1, which prevented α(2,6)-linked sialic acid incorporation, enhanced GAL1-driven regulatory circuits and accelerated tumor progression, effects that were mitigated by GAL1-neutralizing antibodies. Thus, targeting GAL1-glycan interactions may offer opportunities to reprogram MDSCs and enhance the efficacy of immunotherapeutic and anti-angiogenic strategies.

Role of tumor microenvironment in ovarian cancer metastasis and clinical advancements

Ovarian cancer (OC) is the most lethal gynecological malignancy worldwide, characterized by heterogeneity at the molecular, cellular and anatomical levels. Most patients are diagnosed at an advanced stage, characterized by widespread peritoneal metastasis. Despite optimal cytoreductive surgery and platinum-based chemotherapy, peritoneal spread and recurrence of OC are common, resulting in poor prognoses. The overall survival of patients with OC has not substantially improved over the past few decades, highlighting the urgent necessity of new treatment options. Unlike the classical lymphatic and hematogenous metastasis observed in other malignancies, OC primarily metastasizes through widespread peritoneal seeding. Tumor cells (the "seeds") exhibit specific affinities for certain organ microenvironments (the "soil"), and metastatic foci can only form when there is compatibility between the "seeds" and "soil." Recent studies have highlighted the tumor microenvironment (TME) as a critical factor influencing the interactions between the "seeds" and "soil," with ascites and the local peritoneal microenvironment playing pivotal roles in the initiation and progression of OC. Prior to metastasis, the interplay among tumor cells, immunosuppressive cells, and stromal cells leads to the formation of an immunosuppressive pre-metastatic niche in specific sites. This includes characteristic alterations in tumor cells, recruitment and functional anomalies of immune cells, and dysregulation of stromal cell distribution and function. TME-mediated crosstalk between cancer and stromal cells drives tumor progression, therapy resistance, and metastasis. In this review, we summarize the current knowledge on the onset and metastatic progression of OC. We provide a comprehensive discussion of the characteristics and functions of TME related to OC metastasis, as well as its association with peritoneal spread. We also outline ongoing relevant clinical trials, aiming to offer new insights for identifying potential effective biomarkers and therapeutic targets in future clinical practice.

Single-cell and spatial transcriptomics reveals an anti-tumor neutrophil subgroup in microwave thermochemotherapy-treated lip cancer

Microwave thermochemotherapy (MTC) has been applied to treat lip squamous cell carcinoma (LSCC), but a deeper understanding of its therapeutic mechanisms and molecular biology is needed. To address this, we used single-cell transcriptomics (scRNA-seq) and spatial transcriptomics (ST) to highlight the pivotal role of tumor-associated neutrophils (TANs) among tumor-infiltrating immune cells and their therapeutic response to MTC. MNDA+ TANs with anti-tumor activity (N1-phenotype) are found to be abundantly infiltrated by MTC with benefit of increased blood perfusion, and these TANs are characterized by enhanced cytotoxicity, ameliorated hypoxia, and upregulated IL1B, activating T&NK cells and fibroblasts via IL1B-IL1R. In this highly anti-tumor immunogenic and hypoxia-reversed microenvironment under MTC, fibroblasts accumulated in the tumor front (TF) can recruit N1-TANs via CXCL2-CXCR2 and clear N2-TANs (pro-tumor phenotype) via CXCL12-CXCR4, which results in the aggregation of N1-TANs and extracellular matrix (ECM) deposition. In addition, we construct an N1-TANs marker, MX2, which positively correlates with better prognosis in LSCC patients, and employ deep learning techniques to predict expression of MX2 from hematoxylin-eosin (H&E)-stained images so as to conveniently guide decision making in clinical practice. Collectively, our findings demonstrate that the N1-TANs/fibroblasts defense wall formed in response to MTC effectively combat LSCC.

Gut microbiota influences colorectal cancer through immune cell interactions: a Mendelian randomization study

BACKGROUND

Colorectal cancer (CRC) is the most prevalent malignant tumor of the digestive system globally, posing a significant threat to human health and quality of life. Recent studies have established associations between gut microbiota and immune cells with CRC; however, the mechanisms by which gut microbiota influence the development and progression of CRC through immune mediators remain poorly understood.

METHODS

We conducted a two-sample, bidirectional Mendelian randomization analysis. We utilized 731 immune cell types and 473 gut microbial species along with colorectal cancer statistics from published summary statistics from genome-wide association studies (GWAS).The analysis employed several methodologies, including inverse variance-weighted (IVW) analysis, MR-Egger regression, the weighted median method, and both weighted and simple model approaches.Sensitivity analyses were performed to confirm the reliability of the Mendelian randomization results, and reverse Mendelian randomization was used to assess the overall impact of CRC on gut microbiota and immune cells.

RESULTS

Our findings suggest a causal relationship involving nine immunophenotypes and five specific gut microbial taxa with CRC. Notably, the gut microbes Alloprevotella and Holdemania, along with immune cell types CD3 on CD28- CD8br and CD4 + T cells, demonstrated significant causal associations with CRC. Mediation analysis revealed that the association between Alloprevotella and CRC was mediated by CD4 + T cells, with a mediation effect of 6.48%. Additionally, Holdemania was found to mediate its association with CRC through CD3 on CD28- CD8br, exhibiting a mediation effect of 9.29%. Reverse Mendelian randomization did not indicate any causal effect of CRC on specific immune cells or gut microbiota. Two-sided sensitivity analyses revealed no evidence of heterogeneity or horizontal pleiotropy in our findings.

CONCLUSIONS

This comprehensive Mendelian randomization study enhances our understanding of the mechanisms by which gut microbiota affects CRC through immune cell interactions. Further investigations are warranted to unravel the underlying mechanisms linking gut microbiota, immune cells, and colorectal cancer.

Predicting the risk of lymph node metastasis in colon cancer: development and validation of an online dynamic nomogram based on multiple preoperative data

BACKGROUND

Predicting lymph node metastasis (LNM) in colon cancer (CC) is crucial to treatment decision-making and prognosis. This study aimed to develop and validate a nomogram that estimates the risk of LNM in patients with CC using multiple clinical data from patients before surgery.

METHODS

Clinicopathological data were collected from 412 CC patients who underwent Radical resection of CC. The training cohort consisted of 300 cases, and the external validation cohort consisted of 112 cases. The LASSO and multivariate logistic regression were used to select the predictors and construct the nomogram. The discrimination and calibration of the nomogram were evaluated by the ROC curve and calibration curve, respectively. The clinical application of the nomogram was assessed by decision curve analysis(DCA) and clinical impact curves(CIC).

RESULTS

Eight independent factors associated with LNM were identified by multivariate logistic analysis: LN status on CT, tumor diameter on CT, differentiation, ulcer, intestinal obstruction, anemia, blood type, and neutrophil percentage. The online dynamic nomogram model constructed by independent factors has good discrimination and consistency. The AUC of 0.834(95% CI: 0.755-0.855) in the training cohort, 0.872(95%CI: 0.807-0.937) in the external validation cohort, and Internal validation showed that the corrected C statistic was 0.810. The calibration curve of both the training set and the external validation set indicated that the predicted outcome of the nomogram was highly consistent with the actual outcome. The DCA and CIC indicate that the model has clinical practical value.

CONCLUSION

Based on various simple parameters collected preoperatively, the online dynamic nomogram can accurately predict LNM risk in CC patients. The high discriminative ability and significant improvement of NRI and IDI indicate that the model has potential clinical application value.

Evoking the Cancer-immunity cycle by targeting the tumor-specific antigens in Cancer immunotherapy

Cancer-related deaths continue to rise, largely due to the suboptimal efficacy of current treatments. Fortunately, immunotherapy has emerged as a promising alternative, offering new hope for cancer patients. Among various immunotherapy approaches, targeting tumor-specific antigens (TSAs) has gained particular attention due to its demonstrated success in clinical settings. Despite these advancements, there are still gaps in our understanding of TSAs. Therefore, this review explores the life cycle of TSAs in cancer, the methods used to identify them, and recent advances in TSAs-targeted cancer therapies. Enhancing medical professionals' understanding of TSAs will help facilitate the development of more effective TSAs-based cancer treatments.

The cGAS-STING pathway promotes acute ischemia-induced neutropoiesis and neutrophil priming in the bone marrow

Our previous work demonstrated that the DNA-sensing receptor cyclic GMP-AMP synthase (cGAS) negatively affects post-infarct repair by promoting pro-inflammatory macrophages. However, whether cGAS and its downstream partner STING (Stimulator of Interferon Genes) regulate neutrophil production and function in the context of acute myocardial ischemia remains unclear. This study investigated the role of the cGAS-STING pathway in neutropoiesis (neutrophil production and differentiation) and examined whether ischemia primes neutrophils in the bone marrow via this pathway, enhancing their functionality and contributing to cardiac inflammatory injury. Using myocardial infarction (MI) models in wild-type (WT), Cgas-/-, and Sting-/- mice, we analyzed neutrophils from the bone marrow, peripheral blood, and infarcted tissue. Additionally, we generated neutrophil-specific conditional knockouts of Cgas and performed adoptive transfer experiments with Cgas-deficient neutrophils. RNA sequencing revealed that ischemia increased neutrophil production in the bone marrow and activated pathways involved in cytokine signaling, phagocytosis, chemotaxis, and degranulation. Inhibiting the cGAS-STING pathway reduced neutrophil production by decreasing lineage committed neutrophil precursors including early neutrophil precursors (eNP) and preNeu and downregulated ischemia-induced pathways. Neutrophil conditional Cgas deletion or adoptive transfer of Cgas-deficient neutrophils improved survival but did not significantly impact ischemia-induced remodeling. In conclusion, we demonstrate for the first time that ischemia enhanced neutrophil functionality before recruitment to infarcted tissue, and the cGAS-STING pathway played an important role in neutrophil production and priming. Furthermore, our findings demonstrate a neutrophil-specific role of cGAS in promoting cardiac rupture and mortality in MI. This study provides a more comprehensive understanding of the cGAS-STING pathway in acute ischemia and may support the translation of cGAS-STING modulators, an emerging therapeutic field.

Sialic Acids: Sweet modulators fueling cancer cells and domesticating the tumor microenvironment

Tumor microenvironment (TME) can shift towards either immune activation or immunosuppression, influenced by various factors. Recent studies have underscored the pivotal role of sialic acids, a group of monosaccharides with a 9-carbon backbone, in modulating the TME. Aberrant expression or abnormal addition of sialic acids to the surface of cancer cells and within the tumor stroma has been identified as a key contributor to tumor progression. Abnormal sialylation on cancer cell surfaces can inhibit apoptosis, enhance cell proliferation, and facilitate metastasis. Notably, recent findings suggest that dysregulated sialic acid expression in the TME actively contributes to shaping an immunosuppressive niche by reducing the population of anti-tumor immune cells and impairing immune cell function. The mechanisms by which sialic acids foster immune escape and shape the immunosuppressive TME have been partially unraveled, particularly through interactions with sialic acid receptors on immune cells. Importantly, several sialic acid-targeted therapies are currently advancing into clinical trials, offering promising prospects for clinical translation. This dysregulated sialylation represents a significant opportunity for molecular diagnostics and therapeutic interventions in oncology. Targeting aberrant sialylation or disrupting the interaction between sialic acids and their receptors offers potential strategies to reprogram the TME towards an anti-tumor phenotype, thereby facilitating the advancement of innovative cancer therapies.

From Ulcerative Colitis to Metastatic Colorectal Cancer: The Neutrophil Contribution

Ulcerative colitis (UC) is an inflammatory colon and rectum disease affecting approximately 5 million people worldwide. There is no cure for UC, and approximately 8% of patients with UC develop colorectal cancer (CRC) by gradual acquisition of mutations driving the formation of adenomas and their progression to adenocarcinomas and metastatic disease. CRC constitutes 10% of total cancer cases worldwide and 9% of cancer deaths. Both UC and CRC have an increasing incidence worldwide. Although the epithelium has been well studied in UC and CRC, the contribution of neutrophils is less clear. Neutrophils are rapidly recruited in excessive amounts from peripheral blood to the colon during UC, and their overactivation in the proinflammatory UC tissue environment contributes to tissue damage. In CRC, the role of neutrophils is controversial, but emerging evidence suggests that their role depends on the evolution and context of the disease. The role of neutrophils in the transition from UC to CRC is even less clear. However, recent studies propose neutrophils as therapeutic targets for better clinical management of both diseases. This review summarizes the current knowledge on the roles of neutrophils in UC and CRC.

X-ray-activated nanoscintillators integrated with tumor-associated neutrophils polarization for improved radiotherapy in metastatic colorectal cancer

Radiotherapy, employing high-energy rays to precisely target and eradicate tumor cells, plays a pivotal role in the treatment of various malignancies. Despite its therapeutic potential, the effectiveness of radiotherapy is hindered by the tumor's inherent low radiosensitivity and the immunosuppressive microenvironment. Here we present an innovative approach that integrates peroxynitrite (ONOO-)-mediated radiosensitization with the tumor-associated neutrophils (TANs) polarization for the reversal of immunosuppressive tumor microenvironment (TME), greatly amplifying the potency of radiotherapy. Our design employs X-ray-activated lanthanide-doped scintillators (LNS) in tandem with photosensitive NO precursor to achieve in-situ ONOO- generation. Concurrently, the co-loaded TGF-β inhibitor SB525334, released from the LNS-RS nanoplatform in response to the overexpressed GSH in tumor site, promotes the reprogramming of TANs from N2 phenotype toward N1 phenotype, effectively transforming the tumor-promoting microenvironment into a tumor-inhibiting state. This 'one-two punch' therapy efficiently trigger a robust anti-tumor immune response and exert potent therapeutic effects in orthotopic colorectal cancer and melanoma mouse model. Meanwhile, it also significantly prevents liver metastasis and recurrence in metastatic colorectal cancer. The development of X-ray-controlled platforms capable of activating multiple therapeutic modalities may accelerate the clinical application of radiotherapy-based collaborative therapy.

Tumor cells that resist neutrophil anticancer cytotoxicity acquire a prometastatic and innate immune escape phenotype

In the tumor host, neutrophils may exhibit protumor or antitumor activity. It is hypothesized that in response to host-derived or therapy-induced factors, neutrophils adopt diverse functional states to ultimately execute these differential functions. Here, we provide an alternative scenario in which the response of an individual tumor cell population determines the overall protumor versus antitumor outcome of neutrophil‒tumor interactions. Experimentally, we show that human neutrophils, which are sequentially stimulated with bacteria and secreted factors from tumor cells, kill a certain proportion of tumor target cells. However, the majority of the tumor cells remained resistant to this neutrophil-mediated killing and underwent a functional, phenotypic and transcriptomic switch that was reminiscent of partial epithelial‒to-mesenchymal transition. This cell biological switch was associated with physical escape from NK-mediated killing and resulted in enhanced metastasis to the lymph nodes in a preclinical orthotopic mouse model. Mechanistically, we identified the antimicrobial neutrophil granule proteins neutrophil elastase (NE) and matrix metalloprotease-9 (MMP-9) as the molecular mediators of this functional switch. We validated these data in patients with head and neck cancer and identified bacterially colonized intratumoral niches that were enriched for mesenchymal tumor cells and neutrophils expressing NE and MMP-9. Our data reveal the parallel execution of tumor cytotoxic and prometastatic activity by activated neutrophils and identify NE and MMP-9 as mediators of lymph node metastasis. The identified mechanism explains the functional dichotomy of tumor-associated neutrophils at the level of the tumor target cell response and has implications for superinfected cancers and the dysbiotic tumor microenvironment.

Molecular probes for in vivo optical imaging of immune cells

Advancing the understanding of the various roles and components of the immune system requires sophisticated methods and technology for the detection of immune cells in their natural states. Recent advancements in the development of molecular probes for optical imaging have paved the way for non-invasive visualization and real-time monitoring of immune responses and functions. Here we discuss recent progress in the development of molecular probes for the selective imaging of specific immune cells. We emphasize the design principles of the probes and their comparative performance when using various optical modalities across disease contexts. We highlight molecular probes for imaging tumour-infiltrating immune cells, and their applications in drug screening and in the prediction of therapeutic outcomes of cancer immunotherapies. We also discuss the use of these probes in visualizing immune cells in atherosclerosis, lung inflammation, allograft rejection and other immune-related conditions, and the translational opportunities and challenges of using optical molecular probes for further understanding of the immune system and disease diagnosis and prognosis.

Senescent neutrophils: a hidden role in cancer progression

Neutrophils have recently received increased attention in cancer because they contribute to all stages of cancer. Neutrophils are so far considered to have a short half-life. However, a growing body of literature has shown that tumor-associated neutrophils (TANs) acquire a prolonged lifespan. This review discusses recent work surrounding the mechanisms by which neutrophils can persist in the tumor microenvironment (TME). It also highlights different scenarios for therapeutic targeting of protumorigenic neutrophils, supporting the idea that, in tumors, inhibition of neutrophil recruitment is not sufficient because these cells can persist and remain hidden from current interventions. Hence, the elimination of long-lived neutrophils should be pursued to increase the efficacy of standard therapy.

Integrated analysis of single-cell RNA-seq and bulk RNA-seq unravels the molecular feature of tumor-associated neutrophils of head and neck squamous cell carcinoma

BACKGROUND

Head and neck squamous cell carcinoma (HNSCC) is a lethal malignancy with a high recurrence and distant metastasis rate, posing significant challenges to patient prognosis. Recent studies suggest that tumor-associated neutrophils (TANs) can modulate immune cell infiltration and influence tumor initiation and progression. However, the potential clinical significance of TANs in HNSCC remains insufficiently explored.

METHODS

TANs-specific marker genes were identified via single-cell sequencing data from HNSCC. Based on data from The Cancer Genome Atlas (TCGA), a prognostic risk model was constructed using TANs cell marker genes, and the model was validated with data from the Gene Expression Omnibus (GEO) database. The associations between the TANs signature and clinical characteristics, functional pathways, immune cell infiltration, immune checkpoint expression, and responses to immunotherapy and chemotherapy, were then investigated. Cell counting kit-8(CCK-8), Transwell, and wound healing assays were conducted to assess the functional role of TANs marker molecules.

RESULTS

TANs characteristic genes were identified from single-cell sequencing data from HNSCC patients. On the basis of these characteristic genes, a tumor-associated neutrophils-associated signature (NRS) was developed and validated across internal and external cross-platform cohorts through comprehensive procedures. The NRS demonstrated robust and reliable performance in predicting overall survival. Additionally, patients with a low NRS showed enhanced immune cell infiltration, active lipid metabolism, and increased sensitivity to immunotherapy. In contrast, patients with a high NRS exhibited poor prognostic outcomes, advanced clinical stages, and significant associations with HNSCC metastasis and progression. Furthermore, we identified a TANs-associated biomarker, OLR1, and validated that OLR1 promotes HNSCC proliferation, invasion, and migration through CCK-8, Transwell invasion, and wound healing assays.

CONCLUSION

This study has developed a promising TANs-based tool that may aid in personalized treatment and prognostic management for patients with HNSCC.

CD44+ cells enhance pro-tumor stroma in the spatial landscape of colorectal cancer leading edge

BACKGROUND

The heterogeneity of tumors significantly impacts on colorectal cancer (CRC) progression. However, the influence of this heterogeneity on the spatial architecture of CRC remains largely unknown.

METHODS

Spatial transcriptomic (ST) analysis of AOM/DSS-induced colorectal cancer (CRC), integrated with single-cell RNA sequencing, generated a comprehensive spatial atlas of CRC. Pseudotime trajectory, stemness evaluation, and cell-cell communication analyses explored how CD44+ tumor cells at the leading edge remodel the tumor microenvironment (TME). In vitro experiments and immunofluorescence staining of clinical samples validated pleiotrophin (PTN) signaling in promoting cancer-associated fibroblasts (CAFs) phenotypic transition and CRC progression.

RESULTS

Our findings revealed a distinctive layered ring-like structure within CRC tissues, where CD44+ tumor cells exhibiting high stemness were positioned at the tumor's leading edge. Inflammatory CAFs (iCAFs)-like, myofibroblastic CAFs (myCAFs)-like cells and pro-tumorigenic neutrophils primarily located at the tumor edge, in proximity to CD44+ tumor cells. CD44+ tumor cells then triggered the phenotypic transition of CAFs into iCAF-like and myCAF-like cells through PTN signaling.

CONCLUSIONS

Our results provide distinctive insights into how tumor heterogeneity reshapes the TME at the leading edge of tumor, thereby promoting CRC progression.

Angiogenesis and immune microenvironment in triple-negative breast cancer: Targeted therapy

Triple-negative breast cancer (TNBC) is a highly aggressive breast cancer subtype that typically lacks effective targeted therapies, leading to limited treatment options. Chemotherapy remains the primary treatment modality; however, in recent years, new immunotherapy approaches, such as immune checkpoint inhibitors, have shown positive results in some patients. Although the development of TNBC is closely associated with BRCA gene mutations, the tumor immune microenvironment (TIME) plays a crucial role in tumor progression and immune escape. Tumor angiogenesis, the accumulation of immunosuppressive cells, and alterations in immune molecules collectively shape an environment unfavorable for anti-tumor immune responses. Tumor-associated macrophages (TAMs) and myeloid-derived suppressor cells (MDSCs) promote immune escape by secreting immunosuppressive factors. Therefore, combination strategies of anti-angiogenic and immune checkpoint inhibitory therapies have shown synergistic effects in clinical trials, while new targeted therapies such as TGF-β inhibitors and IL-1β inhibitors offer new options for TNBC treatment. With the development of personalized medicine, combining immunotherapy and targeted therapies brings new hope for TNBC patients.

Pan-immune-inflammation value and its association with all-cause and cause-specific mortality in the general population: a nationwide cohort study

Introduction

The Pan-Immune-Inflammation Value (PIV) is a novel biomarker derived from counts of neutrophils, platelets, monocytes, and lymphocytes, providing a comprehensive measure of systemic immune and inflammatory status. While it has shown prognostic value in specific disease settings, its association with mortality in the general population remains unclear. This study aims to evaluate the predictive value of PIV for all-cause and cause-specific mortality, including cardiovascular, cancer, and diabetes-related deaths, within a general adult population.

Methods

Data were obtained from the NHANES cohort, with 48,662 participants aged 20 and older. Participants were followed for an average of 117.44 months, with PIV quartiles calculated at baseline. Cox proportional hazard models were used to assess mortality risk across PIV quartiles, while restricted cubic spline models examined nonlinear dose-response relationships. Subgroup and sensitivity analyses further explored the robustness of PIV's associations.

Results

Higher PIV levels were significantly associated with increased risks of all-cause, cardiovascular, cancer, and diabetes mortality. Nonlinear relationships were observed between PIV and all-cause, cardiovascular, and cancer mortality, with a risk threshold at PIV values above 254.07. Subgroup analyses supported these findings, and sensitivity analyses confirmed the consistency of PIV's prognostic value.

Conclusion

Elevated PIV serves as an independent risk factor for multiple mortality outcomes in the general population. This study underscores the potential of PIV as a predictive biomarker for mortality risk, with implications for its use in clinical and epidemiological settings. Further studies are needed to confirm PIV's clinical utility across diverse populations and conditions.

Neutrophils in cancer: At the crucial crossroads of anti-tumor and pro-tumor

Neutrophils are important components of the immune system and play a key role in defending against pathogenic infections and responding to inflammatory cues, including cancer. Their dysregulation indicates potential disease risk factors. However, their functional importance in disease progression has often been underestimated due to their short half-life, especially as there is limited information on the role of intratumoral neutrophils. Recent studies on their prominent role in cancer have led to a paradigm shift in our understanding of the functional diversity of neutrophils. These studies highlight that neutrophils have emerged as key components of the tumor microenvironment, where they can play a dual role in promoting and suppressing cancer. Moreover, several approaches to therapeutically target neutrophils have emerged, and clinical trials are investigating their efficacy. In this review, we discussed the involvement of neutrophils in cancer initiation and progression. We summarized recent advances in therapeutic strategies targeting neutrophils and, most importantly, suggested future research directions that could facilitate the manipulation of neutrophils for therapeutic purposes in cancer patients.

Distinct immunophenotypic profiles and neutrophil heterogeneity in colorectal cancer

Colorectal cancer (CRC) exhibits significant molecular and immunological heterogeneity. Neutrophil infiltration patterns play a crucial yet poorly understood role in tumor progression and patient outcomes. This study presents a comprehensive single-cell atlas of the CRC tumor microenvironment (TME), integrating transcriptomic data from 388,511 cells across 98 samples from 63 patients. Employing advanced computational methods, we stratified patients based on their immune cell infiltration profiles, revealing distinct immunophenotypes with potential therapeutic implications. Our analysis focused on tissue-resident neutrophils (TRNs) and uncovered previously uncharacterized subpopulations with diverse functional states. Trajectory inference analysis revealed a dynamic differentiation path from normal-associated neutrophils to tumor-associated neutrophils, highlighting the remarkable plasticity of these cells within the tumor environment. By integrating single-cell data with bulk transcriptomic and clinical information, we identified specific neutrophil-derived gene signatures associated with poor prognosis in CRC, suggesting their potential as novel prognostic biomarkers. This study not only provides unprecedented insights into neutrophil heterogeneity in CRC but also identifies potential targets for immunomodulatory therapies. Our findings lay the groundwork for developing more nuanced, personalized immunotherapeutic strategies for CRC, potentially improving treatment efficacy for patients who currently show a limited response to existing immunotherapies.

The miR-941/FOXN4/TGF-β feedback loop induces N2 polarization of neutrophils and enhances tumor progression of lung adenocarcinoma

Background

Lung adenocarcinoma (LUAD) is a major subtype of lung cancer and one of the deadliest cancers in humans. Dysregulation of miRNA activity in tumor-associated neutrophils (TANs) in the tumor microenvironment plays an important role in the occurrence and development of LUAD.

Method

In this study, the miReact algorithm was used to analyze the single-cell RNA sequencing data of LUAD samples to reveal the miRNA profile characteristics of TANs in LUAD patients. The function of miR-941 was investigated in vivo and in vitro. The target gene and underlying signaling pathway of miR-941 were predicted and validated with qPCR, luciferase assay, WB and ELISA assay.

Results

The results indicated the crucial role of TANs, especially N2-TANs in LUAD and miR-941 activity was significantly upregulated in TANs of LUAD patients. MiR-941 overexpression promoted the proliferation, invasion, migration and anti-apoptosis of A549 and H1299. In vivo xenograft mouse model confirmed that miR-941 overexpression enhanced the growth of tumors formed by H1299 cells. Bioinformatics analysis showed that miR-941 targeted the tumor suppressor gene FOXN4, and we confirmed that FOXN4 overexpression could counteract the malignant effects of miR-941. In addition, miR-941 may drive LUAD progression through the FOXN4/TGF-β feedback signaling loop and participate in the N2-TAN polarization.

Conclusion

In summary, these findings reveal the key role of N2-TANs and the miR-941/FOXN4/TGF-β signaling loop in LUAD progression and provide potential therapeutic targets for future interventions.

From neglect to necessity: the role of innate immunity in cutaneous squamous cell carcinoma therapy

As the second most common non-melanoma skin cancer, cutaneous squamous cell carcinoma (cSCC) has experienced a significant increase in incidence. Although clinical detection is relatively easy, a considerable number of patients are diagnosed at an advanced stage, featuring local tissue infiltration and distant metastasis. Cemiplimab, along with other immune checkpoint inhibitors, enhances T cell activation by blocking the PD-1 pathway, resulting in notable improvements in clinical outcomes. Nonetheless, approximately 50% of the patients with advanced cSCC remain unresponsive to this therapeutic approach. It emphasizes the importance of finding innovative therapeutic targets and strategies to boost the success of immunotherapy across a wider range of patients. Therefore, we focused on frequently neglected functions of innate immune cells. Emerging evidence indicates that innate immune cells exhibit considerable heterogeneity and plasticity, fundamentally contributing to tumor initiation and development. The identification and eradication of cancer cells, along with the modulation of adaptive immune responses, are essential roles of these cells. Consequently, targeting innate immune cells to activate anti-tumor immune responses presents significant potential for enhancing immunotherapeutic strategies in cSCC.

Neutrophil-Mediated Tumor Discrimination Biomimetic Nanodevice for Precise Tumor Eradication and Metastasis Cascade Perturbing

The deficient discrimination of tumor cells, limited accumulation of therapeutic agents in tumor foci, and undesirable tumor metastasis result in compromised therapeutic efficacy in antitumor therapy. Neutrophils, the most abundant circulating leukocytes, are key players in tumor progression and have a high affinity to tumors. Herein, a biomimetic tumor discrimination nanodevice (NL-FSB) is developed by harboring a pH-sensitive Fenton agent (FSB) in an activated neutrophil membrane-incorporated liposome for tumor-specific ablation. Inheriting the biointerfacing properties of neutrophils, NL-FSB is endowed with high affinity to tumors. On one hand, NL-FSB can be recruited to acidic tumor sites mediated by chemotaxis attraction and selectively generate reactive oxygen species via amplified Fenton chemical reaction for specific tumor eradication. On the other hand, the biomimetic NL-FSB can also target and bind tumor vascular endothelium or circulating tumor cells (CTCs) in circulation, executing pseudo escort to perturb CTC-neutrophil cluster formation and tumor metastasis cascade. Unprecedentedly, the neutrophil-mediated nanoagent can effectively inhibit the already-formed tumor and prevent tumor metastasis with high specificity. Our study represents a promising yet simple strategy for tumor-specific killing and metastasis cascade blockage via a nanobioengineering functionalization strategy.

Targeting neutrophil extracellular traps in cancer progression and metastasis

Neutrophils serve as pivotal effectors and regulators of the intricate immune system. Their contributions are indispensable, encompassing the obliteration of pathogens and a significant role in both cancer initiation and progression. Conversely, malignancies profoundly affect neutrophil activity, maturation, and lifespans. Cancer cells manipulate their biology to enhance or suppress the key functions of neutrophils. This manipulation is one of the most remarkable defensive mechanisms used by neutrophils, including the formation of neutrophil extracellular traps (NETs). NETs are filamentous structures comprising DNA, histones, and proteins derived from cytotoxic granules. In this review, we discuss the bidirectional interplay in which cancer elicits NET formation, and NETs concurrently facilitate cancer progression. Here, we discuss how vascular dysfunction and thrombosis induced by neutrophils and NETs contribute to an elevated risk of mortality from cardiovascular complications in patients with cancer. Ultimately, we propose a series of therapeutic strategies that hold promise for effectively targeting NETs in clinical settings.

Targeting Redox Signaling Through Exosomal MicroRNA: Insights into Tumor Microenvironment and Precision Oncology

Reactive oxygen species (ROS) play a dual role in cancer progression, acting as both signaling molecules and drivers of oxidative damage. Emerging evidence highlights the intricate interplay between ROS, microRNAs (miRNAs), and exosomes within the tumor microenvironment (TME), forming a regulatory axis that modulates immune responses, angiogenesis, and therapeutic resistance. In particular, oxidative stress not only stimulates exosome biogenesis but also influences the selective packaging of redox-sensitive miRNAs (miR-21, miR-155, and miR-210) via RNA-binding proteins such as hnRNPA2B1 and SYNCRIP. These miRNAs, delivered through exosomes, alter gene expression in recipient cells and promote tumor-supportive phenotypes such as M2 macrophage polarization, CD8+ T-cell suppression, and endothelial remodeling. This review systematically explores how this ROS-miRNA-exosome axis orchestrates communication across immune and stromal cell populations under hypoxic and inflammatory conditions. Particular emphasis is placed on the role of NADPH oxidases, hypoxia-inducible factors, and autophagy-related mechanisms in regulating exosomal output. In addition, we analyze the therapeutic relevance of natural products and herbal compounds-such as curcumin, resveratrol, and ginsenosides-which have demonstrated promising capabilities to modulate ROS levels, miRNA expression, and exosome dynamics. We further discuss the clinical potential of leveraging this axis for cancer therapy, including strategies involving mesenchymal stem cell-derived exosomes, ferroptosis regulation, and miRNA-based immune modulation. Incorporating insights from spatial transcriptomics and single-cell analysis, this review provides a mechanistic foundation for the development of exosome-centered, redox-modulating therapeutics. Ultimately, this work aims to guide future research and drug discovery efforts toward integrating herbal medicine and redox biology in the fight against cancer.

Single-Cell Profiling Reveals Global Immune Responses During the Progression of Murine Epidermal Neoplasms

BACKGROUND/OBJECTIVES

Immune cells determine the role of the tumor microenvironment during tumor progression, either suppressing tumor formation or promoting tumorigenesis. This study aimed to fully characterize immune cell responses during skin tumor progression.

METHODS

Using single-cell RNA sequencing, we analyzed the profile of immune cells in the tumor microenvironment of control mouse skins and skin tumors at the single-cell level.

RESULTS

We identified 15 CD45+ immune cell clusters, which broadly represent the most functionally characterized immune cell types including macrophages, Langerhans cells (LC), conventional type 1 dendritic cells (cDC1), conventional type 2 dendritic cells (cDC2), migratory/mature dendritic cells (mDC), dendritic epidermal T cells (DETC), dermal γδ T cells (γδT), T cells, regulatory T cells (Tregs), natural killer cells (NK), type 2 innate lymphoid cells (ILC2), neutrophils (Neu), mast cells (Mast), and two proliferating populations (Prolif.1 and Prolif.2). Skin tumor progression reprogramed immune cells and led to a marked increase in the relative percentages of macrophages, cDC2, mDC, Tregs, and Neu. Macrophages, the largest cell cluster of immune cells in skin tumors. In addition, macrophages emerged as the predominant communication 'hub' in skin tumors, highlighting the importance of macrophages during skin tumor progression. In contrast, other immune cell clusters decreased during skin tumor progression, including DETC, γδT, ILC2, and LC. In addition, skin tumor progression dramatically upregulated Jak2/Stat3 expression and the interferon response across various immune cell clusters. Further, skin tumor progression activated T cells and NK cells indicated by elevated expression of IFN-γ and Granzyme B in skin tumors. Meanwhile, a pronounced infiltration of M2-macrophages and Tregs in skin tumors created an immunosuppressive microenvironment, consistent with the elevated expression of the Stat3 pathway in skin tumors.

CONCLUSIONS

Our study elucidates the immune cell landscape of epidermal neoplasms, offering a comprehensive understanding of the immune response during skin tumor progression and providing new insights into cancer immune evasion mechanisms.

Associations between neutrophil percentage-to-albumin ratio with all-cause and cause-specific mortality among US cancer survivors: evidence from NHANES 2005-2018

Background

The neutrophil percentage-to-albumin ratio (NPAR) had been suggested as a potential prognostic biomarker in various health outcomes. However, its association with mortality in cancer survivors remains unclear.

Methods

A total of 3,022 cancer survivors from the National Health and Nutrition Examination Survey (NHANES) 2005-2018 were linked to mortality outcomes from the National Death Index (NDI). Weighted Cox proportional hazards models was conducted to investigate the association between NPAR and all-cause, cancer and cardiovascular disease (CVD) mortality and the hazard ratio (HR) with 95% confidence interval (CI) were calculated. Restricted cubic spline (RCS) was used to clarify the non-linear association. Additionally, analyses for stratification and sensitivity were performed.

Results

During a median follow-up of 75 months, 790 all-cause deaths occurred, including 244 from cancer and 209 from CVD. After adjustment for covariates, higher NPAR was independently associated with increased risk of all-cause mortality (HR = 1.09, 95% CI = 1.06-1.13), cancer mortality (HR = 1.05, 95% CI = 0.99-1.12), and CVD mortality (HR = 1.13, 95% CI = 1.06-1.21). The RCS revealed a U-shaped relationship for all-cause and cancer mortality, with thresholds of 12.76 and 13.60, respectively. Below the threshold, higher NPAR was associated with a reduced risk of mortality (HR = 0.90, 95% CI = 0.82-0.99; HR = 0.87, 95% CI = 0.76-0.99), whereas above the threshold, the risk of mortality increased significantly (HR = 1.14, 95% CI = 1.09-1.18; HR = 1.15, 95% CI = 1.07-1.24). Subgroup and sensitivity analyses confirmed these findings.

Conclusion

The U-shaped association with all-cause and cancer mortality, along with the linear association with CVD mortality, underscores the potential of NPAR as a valuable prognostic marker in cancer survivors.

Fumarate integrates metabolism and immunity in diseases

Fumarate is a key metabolite produced primarily by the tricarboxylic acid (TCA) and urea cycles. In addition to having a metabolic role, its electrophilicity enables it to covalently modify cysteines; moreover, because of its α-ketoglutarate (α-KG)-like structure, it can also act as a competitive inhibitor of α-KG-dependent dioxygenases for epigenetic remodeling. Recent advances have broadened the role of fumarate as a bridge between metabolism and both innate and adaptive immunity, suggesting potentially important functions in anticancer immunity and autoimmune diseases. Here we review the connections between fumarate metabolism and immunity; we describe the mechanisms of fumarate regulation in cancer, autoimmunity, and other diseases; and we explore the clinical implications of fumarate and its esters for immunotherapy.

Assessment of lncRNA biomarkers based on NETs for prognosis and therapeutic response in ovarian cancer

Ovarian cancer (OC) usually progresses rapidly and is associated with high mortality, while a reliable clinical factor for OC patients to predict prognosis is currently lacking. Recently, the pathogenic role of neutrophils releasing neutrophil extracellular traps (NETs) in various cancers including OC has gradually been recognized. The study objective was to determine whether NETs-related biomarkers can be used to accurately predict the prognosis and guide clinical decision-making in OC. In this study, we utilized univariate and multivariate Cox regression to identify key prognostic features and developed a model with six NETs-related lncRNAs, selected via LASSO regression. The model's predictive capability was assessed through Kaplan-Meier, ROC, and Cox analyses. To understand the model's mechanisms, we conducted GO term analysis, KEGG pathway enrichment, and GSEA. We also analyzed gene mutation status, tumor mutation load, survival rates, and model correlation. Additionally, we compared immune functions, immune checkpoint expression, and chemotherapy sensitivity between risk groups. Besides, we validated the model's predictive value using test data and tissues acquired from our institution. Finally, we performed in vitro and in vivo experiments to confirm the expression of model lncRNAs and the cellular level function of GAS5. We developed a model using six NETs-associated lncRNAs: GAS5, GBP1P1, LINC00702, LINC01933, LINC02362, and ZNF687-AS1. The model's predictive performance, evaluated via ROC curve, was compared with traditional clinicopathological features. GO process analysis highlighted molecular functions related to antigen binding and immune system biological processes. Variations were observed in transcription regulators affecting immune response, inflammation, cytotoxicity, and regulation. We also predicted IC50 values for chemotherapeutic drugs (bexarotene, bicalutamide, embelin, GDC0941, and thapsigargin) in high- and low-risk groups, finding higher IC50 values in low-risk patients. The risk model's robustness was validated using OC cells, tissues, and clinical datas.