Neutrophil profiling illuminates anti-tumor antigen-presenting potency

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.

Immune-based strategies for the treatment of biofilm infections

Biofilms are bacterial communities surrounded by a polymeric matrix that can form on implanted materials and biotic surfaces, resulting in chronic infection that is recalcitrant to immune- and antibiotic-mediated clearance. Therefore, biofilm infections present a substantial clinical challenge, as treatment often involves additional surgical interventions to remove the biofilm nidus, prolonged antimicrobial therapy to clear residual bacteria, and considerable risk of treatment failure or infection recurrence. These factors, combined with progressive increases in antimicrobial resistance, highlight the need for alternative therapeutic strategies to circumvent undue morbidity, mortality, and resource strain on the healthcare system resulting from biofilm infections. One promising option is reprogramming dysfunctional immune responses elicited by biofilm. Here, we review the literature describing immune responses to biofilm infection with a focus on targets or strategies ripe for clinical translation. This represents a complex and dynamic challenge, with context-dependent host-pathogen interactions that differ across infection models, microenvironments, and individuals. Nevertheless, consistencies among these variables exist, which could facilitate the development of immune-based strategies for the future treatment of biofilm infections.

Single-cell transcriptomics reveal the effects of chemoimmunotherapy on hypopharyngeal cancer and its tumor microenvironment

Induction chemoimmunotherapy (ICIT) has emerged as a potential treatment option for resectable hypopharyngeal cancer (HPC), while its effectiveness remains limited to a significant portion of HPC cases, and a major challenge behind lies in the lack of reliable molecular markers to identify treatment-resistant patients. In this study, we analyzed biopsy samples of HPC patients collected before and after ICIT, classifying them based on treatment response. By investigating the tumor microenvironment (TME) at the single-cell level, we demonstrated that the heterogeneity within the TME is closely linked to different treatment outcomes. Specially, a strong treatment response correlated with a subpopulation of cancer-associated fibroblasts (CAFs). Additionally, we identified that the S100A2 gene is highly expressed in tumor cells and appears to influence ICIT efficacy. Using bulk RNA sequencing, we estimated cell composition and validated these observations at the protein level. Our research provides a novel approach for identifying genes and cell populations that predict treatment responses in HPC, potentially enabling the timely identification of treatment-resistant patients. This could increase the likelihood of preserving laryngeal function and optimizing treatment strategies.

Fibrinogen-like 2 in tumor-associated macrophage-derived extracellular vesicles shapes an immunosuppressive microenvironment in colorectal liver metastases by promoting tumor stemness and neutrophil extracellular traps formation

Investigating the mechanisms underlying the development of an immunosuppressive microenvironment within colorectal liver metastases (CRLM) is important for identifying synergistic targets for immunotherapy. The regulatory role of tumor-associated macrophage-derived extracellular vesicles (TAM-EVs) in the immune microenvironment of CRLM has not yet been fully explored. Here, we found that TAM-EVs shaped the immunosuppressive microenvironment at the invasive front in murine CRLM models, thus dampening anti-PD-1 immunotherapy. This environment is characterized by an increased tumor stemness potential and abundant neutrophil extracellular traps (NETs) formation. Mechanistically, TAM-EVs-derived fibrinogen-like 2 (FGL2) interacts with the FCGR2B receptor in tumor cells, which further activates a p-STAT3/IL-1β positive feedback loop to increase the stemness potential of cancer cells, whereas IL-1β mediates the communication between cancer cells and neutrophils. The use of an anti-IL-1β monoclonal antibody can reduce NETs production and synergize with anti-PD-1 immunotherapy, which offers clinical translational significance for CRLM therapy. The FGL2/p-STAT3/IL-1β loop correlates with an immunosuppressive microenvironment and poor prognosis in human patients with CRLM. Our results revealed the potential of enhancing the efficacy of immunotherapy via the targeted clearance of NETs using anti-IL-1β monoclonal antibodies, which have significant clinical translational value in the treatment of CRLM.

Targeting mitochondrial complex I of CD177+ neutrophils alleviates lung ischemia-reperfusion injury

Primary graft dysfunction (PGD) is the leading cause of early morbidity and mortality following lung transplantation, with neutrophils playing a central role in its inflammatory pathology. Here, we employ single-cell RNA sequencing and spatial transcriptomics to investigate neutrophil subtypes in the lung ischemia-reperfusion injury (IRI) model. We identify CD177+ neutrophils as an activated subpopulation that significantly contributes to lung injury and serves as an early biomarker for predicting severe PGD in human lung transplant recipients (area under the curve [AUC] = 0.871). CD177+ neutrophils exhibit elevated oxidative phosphorylation and increased mitochondrial complex I activity, driving inflammation and the formation of neutrophil extracellular traps. Targeting mitochondrial function with the complex I inhibitor IACS-010759 reduces CD177+ neutrophil activation and alleviates lung injury in both mouse IRI and rat left lung transplant models. These findings provide a comprehensive landscape of CD177+ neutrophil-driven inflammation in lung IRI and highlight its potential value for future early diagnosis and therapeutic interventions.

Dissecting small cell carcinoma of the esophagus ecosystem by single-cell transcriptomic analysis

Small cell carcinoma of the esophagus (SCCE) is an aggressive and rare neuroendocrine malignancy with poor prognosis. Here, we firstly performed single-cell transcriptional profiling derived from 10 SCCE patients, with normal esophageal mucosa, adjacent non-malignant tissue and tumors from esophageal squamous cell carcinoma (ESCC) as reference. We observed enrichment of activated regulatory T cells and an angiogenesis-induced niche existed in SCCE compared with ESCC, revealing an immune suppressive and vessel-induced tumor microenvironment (TME) in SCCE. Totally, we identified five TME ecotypes (EC1 ~ 5). Notably, EC1 was highly enriched in SCCE, associating with molecular subtyping and survival outcomes. To dissecting heterogeneity of epithelium in SCCE, we constructed eight transcriptional metaprograms (MPs) that underscored significant heterogeneity of SCCE. High expression of MP5 was linked to neuroendocrine phenotype and poor clinical survival. Collectively, these results, for the first time, systematically deciphered the TME and epithelial heterogeneity of SCCE and provided evidences that SCCE patients might benefit from anti-angiogenesis therapy.

IL7-IL7R Interaction Mediates Fibroblast-Driven Macrophage-to-Osteoclast Differentiation in Periodontitis

Aim

To identify osteoclastogenic macrophage subsets and their regulatory mechanisms in periodontitis.

Methods

We integrated single-cell RNA sequencing datasets from human and murine periodontitis to construct a comprehensive macrophage and monocyte atlas. Employing functional enrichment, cell-cell communication, pseudotime, transcription factor, and machine learning analyses, we characterized and selected the specific macrophage subset involved in cell interactions. In vitro and in vivo experiments, including enzyme-linked immunosorbent assay, TRAP staining, micro-CT, qPCR, flow cytometry, and immunofluorescence staining, were performed to dissect the osteoclastogenic potential of specific macrophage subsets and to identify the key pathways.

Results

We discovered that the IL7R+ macrophage subset possesses significant osteoclast differentiation potential. Our findings indicate that the IL7/IL7R signaling axis facilitates osteoclast differentiation. Genes highly expressed in IL7R+ macrophages were identified as strong predictors for periodontitis by machine learning models. In vivo and in vitro experimental validation confirmed an increase in IL7R+ macrophages, along with their enhanced osteoclastogenic capacity. confirmed an increase in IL7R+ macrophages, along with their osteoclastogenic capacity. The inhibition of the IL7/IL7R signaling pathway was found to mitigate periodontitis progression by impeding osteoclast differentiation. Furthermore, fibroblasts were found to secret IL7 interacting with IL7 receptors on macrophages.

Conclusion

Our study identifies IL7R+ macrophages as potential osteoclast precursors in periodontitis. We demonstrate that the IL7/IL7R signaling pathway is a critical driver of osteoclast differentiation. Moreover, targeting IL7R is a potential therapeutic strategy to curb periodontitis bone resorption.

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.

Cancer-nervous system crosstalk: from biological mechanism to therapeutic opportunities

A growing body of research suggests a bidirectional interaction between cancer and the nervous system. Neural cells exert their effects on tumors by secreting neurotransmitters and cell adhesion molecules, which interact with specific receptors on tumor cells to modulate their behavior. Conversely, tumor-secreted factors, particularly including inflammatory factors, can alter neural activity and increase neuronal excitability, potentially contributing to neurological manifestations such as epilepsy. The immune system also serves as a crucial intermediary in the indirect communication between cancer and the nervous system. These insights have opened promising avenues for novel therapeutic strategies targeting both tumors and their associated neurological complications. In this review, we have synthesized the key biological mechanisms underlying cancer-nervous system interactions that have emerged over the past decade. We outline the molecular and cellular pathways mediating this cross-talk and explore the clinical implications of targeting the nervous system to suppress tumor growth and metastasis, mitigate neurological complications arising from cancer progression, and modulate the immune response through neural regulation in the context of cancer therapy.

Subtypes of tumor-associated neutrophils and their roles in cancer immunotherapy

Neutrophils are essential components of the innate immune system. Tumor-associated neutrophils (TANs) are shaped by tumor microenvironment (TME), leading to significant heterogeneity in biological characteristics and functions. Recent advances in single-cell sequencing have revealed a wide array of TAN subtypes, while a comprehensive classification system is still lacking. This review aims to summarize the alterations observed in TAN subgroups following cancer immunotherapy, and identify the distinctions and commonalities between pro-tumor and anti-tumor subgroups. Current progress of preclinical and clinical studies is also highlighted, involving novel therapies targeting TANs.

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.

Deep scSTAR: leveraging deep learning for the extraction and enhancement of phenotype-associated features from single-cell RNA sequencing and spatial transcriptomics data

Single-cell sequencing has advanced our understanding of cellular heterogeneity and disease pathology, offering insights into cellular behavior and immune mechanisms. However, extracting meaningful phenotype-related features is challenging due to noise, batch effects, and irrelevant biological signals. To address this, we introduce Deep scSTAR (DscSTAR), a deep learning-based tool designed to enhance phenotype-associated features. DscSTAR identified HSP+ FKBP4+ T cells in CD8+ T cells, which linked to immune dysfunction and resistance to immune checkpoint blockade in non-small cell lung cancer. It has also enhanced spatial transcriptomics analysis of renal cell carcinoma, revealing interactions between cancer cells, CD8+ T cells, and tumor-associated macrophages that may promote immune suppression and affect outcomes. In hepatocellular carcinoma, it highlighted the role of S100A12+ neutrophils and cancer-associated fibroblasts in forming tumor immune barriers and potentially contributing to immunotherapy resistance. These findings demonstrate DscSTAR's capacity to model and extract phenotype-specific information, advancing our understanding of disease mechanisms and therapy resistance.

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.

IL-1β+ macrophages and the control of pathogenic inflammation in cancer

While highlighting the complexity and heterogeneity of tumor immune microenvironments, the application of single-cell analyses in human cancers has identified recurrent subsets of tumor-associated macrophages (TAMs). Among these, interleukin (IL)-1β+ TAMs - cells with high levels of expression of inflammatory response and tissue repair genes, but with limited capacity to stimulate cytotoxic immunity - are emerging as key drivers of pathogenic inflammation in cancer. In this review we discuss recent literature defining the phenotypical, molecular, and functional properties of IL-1β+ TAMs, as well as their temporal dynamics and spatial organization. Elucidating the biology of these cells across tumor initiation, progression, metastasis, and therapy could inform the design and interpretation of clinical trials targeting IL-1β and/or other inflammatory factors in cancer immunotherapy.

Geranyl hydroquinone alleviates rheumatoid arthritis-associated pain by suppressing neutrophil accumulation, N1 polarization and ROS production in mice

Pain hypersensitivity is a hallmark of rheumatoid arthritis (RA); however, the underlying mechanisms and effective therapies remain largely undefined. Emerging studies suggest that neutrophils play a significant role in the pathology of RA, yet their involvement in RA-associated pain is still unclear. The present study investigates whether neutrophil activity contributes to pain pathogenesis in RA. Our flow cytometry analysis reveals that the accumulation and N1 polarization (indicated by the ratio of CD45+CD66b+CD95+ subset) of neutrophils occur in synovial fluid samples from RA patients, positively correlating with pain scores. In the collagen-induced rheumatoid arthritis (CIA) model, mice demonstrate neutrophil accumulation, N1 polarization (indicated by the ratio of CD45+Ly-6G+CD95+ subset), and reactive oxygen species (ROS) production in affected paw tissues. Geranyl hydroquinone (GHQ), a natural meroterpenoid with antioxidative properties, reverses N1 polarization and ROS production in synovial neutrophils from RA patients in vitro. Moreover, a 10-day oral administration of GHQ alleviates pain hypersensitivity and reduces neutrophil accumulation, N1 polarization, and ROS production in CIA mice. Notably, GHQ treatment reverses TNF-α-evoked ROS production in neutrophils in vitro through downregulating gene expression associated with the ROS pathway. Further, liquid chromatography-tandem mass spectrometry and biochemical analyses indicate that GHQ binds to microsomal glutathione S-transferase 3 (MGST3) in neutrophils. In vitro and in vivo evidence demonstrates that the RA-specific analgesic and antioxidative effects of GHQ require MGST3. Lastly, GHQ administration exhibits superior therapeutic effects compared to methotrexate, a first-line disease-modifying antirheumatic drug, in CIA mice. Collectively, our findings indicate that neutrophil accumulation, N1 polarization and ROS production contribute to RA-associated pain, suggesting that targeting these pathways, such as with GHQ, could be a viable strategy for RA treatment.

Epigenetic modification and tumor immunity: Unraveling the interplay with the tumor microenvironment and its therapeutic vulnerability and implications

In the ever-evolving arena of molecular biology, epigenetic modifications stand out as crucial determinants in the orchestration of cellular identity, function, and fate. This review analyzes the close relationship between epigenetics and tumor immunity, emphasizing the intricate interplay with the tumor microenvironment (TME). Rooted in the knowledge that the incidence of cancer correlates strongly with the biological and genetic age, we highlight DNA methylation as a cornerstone of the "epigenetic aging" process with close ties to tumorigenesis. The TME, with its diverse cellular and acellular constituents, is an active participant in tumor biology, further complicated by epigenetic alterations. These modifications, from DNA methylation to histone changes, not only shape the TME but are reciprocally influenced by it, reinforcing a cycle that propels malignancy. Through this exploration, we underline the importance of understanding this mutual relationship, as it holds significant implications for tumor growth, heterogeneity, and therapeutic resistance. Ultimately, this review illuminates the potential of harnessing epigenetic insights for innovative cancer therapeutic strategies, pointing towards a promising avenue for future cancer management.

Resistance to anti-LAG-3 plus anti-PD-1 therapy in head and neck cancer is mediated by Sox9+ tumor cells interaction with Fpr1+ neutrophils

Relatlimab and nivolumab combination therapy shows significant efficacy in treating various types of cancer. Current research on the molecular mechanisms of this treatment is abundant, but in-depth investigations into post-treatment resistance remain notably lacking. In this study, we identify significant enrichment of SRY (sex determining region Y)-box 9 (Sox9)+ tumor cells in resistant samples using single cell RNA sequencing (scRNAseq) in a head and neck squamous cell carcinoma (HNSCC) mouse model. In addition, Sox9 directly regulates the expression of annexin A1 (Anxa1), mediating apoptosis of formyl peptide receptor 1 (Fpr1)+ neutrophils through the Anxa1-Fpr1 axis, which promotes mitochondrial fission, inhibits mitophagy by downregulating BCL2/adenovirus E1B interacting protein 3 (Bnip3) expression and ultimately prevents the accumulation of neutrophils in tumor tissues. The reduction of Fpr1+ neutrophils impairs the infiltration and tumor cell-killing ability of cytotoxic Cd8 T and γδT cells within the tumor microenvironment, thereby leading to the development of resistance to the combination therapy. We further validate these findings using various transgenic mouse models. Overall, this study comprehensively explains the mechanisms underlying resistance to the anti-LAG-3 plus anti-PD-1 combination therapy and identifies potential therapeutic targets to overcome this resistance.

Unveiling the heterogeneity and immunotherapy potency of tumor-associated neutrophils in the tumor microenvironment of gastric cancer

BACKGROUND

The differentiation characteristics of neutrophils within the gastric cancer (GC) tumor microenvironment (TME) and their interactions with malignant gastric epithelial cells require further investigation. Furthermore, the therapeutic potential of tumor-associated neutrophils (TANs) in immunotherapy remains inadequately explored.

METHODS

We integrated two single-cell transcriptome datasets comprising 12 samples, including gastric primary tumors, non-tumor tissues, and metastatic tumors, to profile the epithelial cells and TANs atlas within the TME and examine their interaction modules. In addition, these data were integrated with the bulk transcriptomic including the Cancer Genome Atlas - Stomach Adenocarcinoma (TCGA-STAD) and Asian Cancer Research Group (ACRG) datasets to analyze the expression levels of neutrophil-associated genes across the tumor-associated neutrophil subsets.

RESULTS

We analyzed 3,118 gastric epithelial cells and 2,365 TANs from all samples. Epithelial cells were classified into ten subclusters, while TANs were grouped into five subclusters. In gastric primary tumors, epithelial cell subtypes included primarily MUC16 + and stem-like populations. In metastatic tumors, the epithelial cell subset with high CXCL5 expression was a characteristic subtype. TANs mainly interacted with epithelial cells via the LGALS9-CD45 and CD46-JAG1 pathways. And RGS2 was highly expressed in N4, a tumor-associated neutrophils subcluster characterized by high MMP9 expression, highlighting its potential as an immunotherapy target.

CONCLUSION

TANs exhibit robust interactions with gastric malignant epithelial cell subsets. Furthermore, RGS2, which is highly expressed in N4, could serve as a promising target for immunotherapy.

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.

Immunometabolism of Innate Immune Cells in Gastrointestinal Cancer

Cancer cells are often described as voracious consumers of nutrients, with glucose frequently cited as a key energy source; however, their metabolic plasticity allows them to adapt and utilize various substrates, including lipids and amino acids, to sustain growth and survival. However, the metabolic demands of immune cells within the tumor microenvironment (TME) are less commonly discussed despite their critical role in shaping the immune response. In this review, we explored the intricate interplay between immunometabolism and innate immunity cells in gastrointestinal cancers. We focused on how metabolic pathways, including glycolysis, fatty acid oxidation, and amino acid metabolism, drive the immunosuppressive functions of myeloid-derived suppressor cells (MDSCs) and tumor-associated neutrophils (TANs), tumor-associated macrophages (TAMs) and innate lymphocyte subsets such as NK cells. These cells contribute to a hostile immune landscape, supporting tumor growth and evasion from immune surveillance in a phenomenon of tumor-derived immunosuppression. Additionally, we investigated the influence of dietary interventions on the metabolic reprogramming of these immune cells, highlighting how nutrition can modulate the TME. Finally, we discussed emerging therapeutic strategies that target metabolic vulnerabilities in MDSCs, TANs, NK cells, and monocytes, offering a novel avenue for enhancing antitumor immunity. By dissecting these mechanisms, we aim to provide insights into how metabolic pathways can be harnessed to improve cancer treatment outcomes. This review underscores the importance of understanding immunometabolism not only as a driver of immune suppression but also as a potential therapeutic target in gastrointestinal cancer.

Spatiotemporal regulation of neutrophil heterogeneity in health and disease

Neutrophils are the most abundant leukocytes in humans and are indispensable for innate immunity. They are short-lived, terminally differentiated cells. However, mounting evidence indicates that neutrophils are heterogeneous in health and disease: they are young or aged in a steady state, while their heterogeneity becomes more diverse in disease conditions, such as cancer, sepsis, and thromboinflammation. Although the presence of distinct neutrophil subsets is well recognized, it is not fully understood how neutrophils have functional and phenotypic heterogeneity and what mechanisms control it. This review will focus on our current understanding of the molecular basis for neutrophil heterogeneity in pathophysiological conditions. In addition, we will discuss the possibility of targeting a specific subset of neutrophils to attenuate inflammation and tissue damage without compromising innate immune responses.

YEATS2: a novel cancer epigenetic reader and potential therapeutic target

YEATS2, an evolutionarily conserved reader of histone acylation marks (H3K27ac, H3K27cr, H3K27bz), functions as a central oncogenic driver in diverse cancers, including non-small cell lung cancer (NSCLC), pancreatic ductal adenocarcinoma (PDAC), and hepatocellular carcinoma (HCC). Its structurally plastic YEATS domain bridges acyl-CoA metabolism to chromatin remodeling, amplifying transcription of survival genes such as MYC, BCL2, and PD-L1. YEATS2 orchestrates malignancy-specific programs-sustaining ribosome biogenesis in NSCLC through ATAC complex recruitment, enhancing NF-κB-dependent immune evasion in PDAC, and activating PI3K/AKT-driven metabolic rewiring in HCC. Structural studies demonstrate a unique aromatic cage architecture that selectively engages diverse acylated histones. Although pyrazolopyridine-based inhibitors targeting the YEATS domain show preclinical efficacy, developing isoform-selective agents remains challenging. Clinically, YEATS2 overexpression correlates with therapy resistance and may synergize with immune checkpoint blockade. This review integrates mechanistic insights into the role of YEATS2 in epigenetic regulation, evaluates its therapeutic potential, and proposes future directions: elucidating full-length complex topologies, mapping synthetic lethal interactors, and optimizing selective inhibitors. Disrupting YEATS2-mediated epigenetic adaptation presents novel opportunities for precision cancer therapy.

Neutrophil single-cell analysis identifies a type II interferon-related subset for predicting relapse of autoimmune small vessel vasculitis

To identify the dynamics of neutrophil autoimmunity, here we focus on anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis and perform single-cell transcriptome and surface proteome analyses on peripheral white blood cells from patients with new-onset microscopic polyangiitis (MPA). Compared with controls, two neutrophil populations, immature neutrophils and neutrophils with type II interferon signature genes (Neu_T2ISG), are increased in patients with MPA. Trajectory and cell-cell interaction analyses identify Neu_T2ISG as a subset that differentiates from mature neutrophils upon stimulation with IFN-γ and TNF, which synergize to induce myeloperoxidase and Fcγ receptors expression on the neutrophil cell surface and promote ANCA-induced neutrophil extracellular trap formation. Case-by-case analysis indicates that patients with a high proportion of the Neu_T2ISG subset are associated with persistent vasculitis symptoms. A larger cohort analysis shows that serum IFN-γ levels at disease onset correlate with susceptibility to disease relapse. Our findings thus identify neutrophil diversity at the single cell level and implicate a biomarker for predicting relapse in small vessel vasculitis.

Metabolic reprogramming of tumor-associated neutrophils in tumor treatment and therapeutic resistance

Tumor-associated neutrophils (TANs), pivotal immune cells within the tumor microenvironment (TME), exhibit dual potential in both pro- and anti-tumorigenic effects. These cells display remarkable heterogeneity and plasticity within the TME, adapting to hypoxic and nutrient-deprived conditions through metabolic reprogramming while critically influencing tumor progression, metastasis, and immune evasion. The metabolic reprogramming of TANs not only modulates their functional phenotypes but also reshapes tumor biological behaviors and therapeutic responses by regulating metabolic intermediates and cellular interactions within the TME. Therefore, elucidating the mechanisms underlying TANs metabolic reprogramming has significant implications for deciphering the molecular basis of tumorigenesis, identifying novel therapeutic targets, and optimizing immunotherapeutic strategies. This review systematically summarizes current knowledge regarding metabolic reprogramming mechanisms of TANs in the TME and their impact on tumor progression. We particularly focus on: 1) TAN-specific alterations in glucose, lipid, and amino acid metabolism within the TME; 2) Emerging immunotherapeutic strategies targeting TANs metabolic pathways; 3) Recent advances in understanding TAN-mediated immune evasion and therapy resistance. Furthermore, this review discusses potential challenges and corresponding solutions in targeting TANs metabolic reprogramming for therapeutic intervention, aiming to provide novel insights for advancing cancer immunotherapy.

Role of Neutrophils in Anti-Tumor Activity: Characteristics and Mechanisms of Action

As one of the leading components in the immune system, neutrophils in the tumor microenvironment (TME) have received considerable attention in recent years. The tumor-killing effects of neutrophils in a variety of tumors have been reported. However, the functions of neutrophils in tumors remain to be completely elucidated, and both anti-tumor and tumor-promotion activities have been reported. This review focuses on the characteristics of neutrophils and their mechanisms of action in the TME, with an emphasis on their anti-tumor activity, including reactive oxygen species (ROS)-induced tumor killing, cytotoxic T lymphocytes (CTLs)-induced tumor killing, trogocytosis, cytotoxic enzymes, and trained immunity. Furthermore, the possible targets and methods of tumor treatment regimens for neutrophils are explored, with the aim of exploring the use of neutrophils in the future as a potential anti-tumor treatment strategy.

ARL8B regulates lysosomal function and predicts poor prognosis in hepatocellular carcinoma

Adenosine 5'-diphosphate ribosylation factor-like 8B (ARL8B), a small GTPase, is involved in lysosome motility. Our study investigates the role of ARL8B in hepatocellular carcinoma (HCC) using in vitro and in vivo experiments, bioinformatics, and clinical data. We found that ARL8B expression is abnormally elevated in HCC and correlates with poor prognosis. ARL8B knockdown triggered lysosomal dysfunction-manifesting as abnormal morphology, decreased pH, reduced hydrolase activity, and impaired autophagic degradation-which subsequently led to cell cycle arrest and reduced cell viability. Additionally, tumors with high ARL8B expression (ARL8Bhigh) exhibited notable differences in tumor microenvironment composition compared to those with low ARL8B expression (ARL8Blow). ARL8Bhigh HCCs had significantly increased infiltration of NFKBIZ+/HIF1A+ and VEGFA+/SPP1+ neutrophils. EcoTyper analysis indicated that ARL8Bhigh HCCs had a lower proportion of carcinoma ecotype 6, a cellular ecosystem common in normal tissues but rare in tumors. Bioinformatics and real-world analysis showed a positive correlation between ARL8B and PD-L1 expression. Patients with high ARL8B expression exhibited increased sensitivity to sorafenib and immune checkpoint blockade therapy. In conclusion, our findings identify ARL8B as a key lysosomal regulator associated with tumor microenvironment composition in HCC, suggesting its potential as both a therapeutic target and a biomarker for predicting treatment response.

PRMT5 deficiency in myeloid cells reprograms macrophages to enhance antitumor immunity and synergizes with anti-PD-L1 therapy

BACKGROUND

Arginine methyltransferase protein arginine methyltransferase 5 (PRMT5) plays a significant role in immune regulation, particularly within the tumor microenvironment (TME). Macrophages are crucial modulators of both innate and adaptive immune responses, and their differentiation into tumor-associated macrophages is critical in shaping the TME. Despite ongoing clinical trials of small molecule inhibitors of PRMT5 for cancer therapy, their effects on macrophages, a key component of the immune system, remain poorly understood.

METHODS

A pan-cancer single-cell transcriptional analysis was initially conducted to investigate the expression of PRMT5 in tumor-infiltrating myeloid cells. Myeloid-specific deletion of Prmt5 in mice, as well as the use of a PRMT5-specific inhibitor, was performed to evaluate the impact of PRMT5 on macrophage polarization and tumor progression. Bulk and single-cell transcriptomics were employed to explore the mechanistic roles of PRMT5 in regulating lipid metabolism and macrophage polarization. Additionally, the therapeutic potential of combining Prmt5 deletion with anti-programmed death-ligand 1 (PD-L1) therapy was assessed to study its effects on antitumor immunity in vivo.

RESULTS

The pan-cancer single-cell transcriptional analysis revealed that PRMT5 is highly expressed in the PPARG-macrophage subset, which correlates with poor patient survival. Myeloid-specific deletion of Prmt5 reprogrammed macrophages towards an antitumor phenotype, effectively inhibiting tumor progression. Mechanistically, PRMT5 was found to regulate lipid metabolism and drive macrophage polarization toward an anti-inflammatory state via the STAT6-PPARγ pathway, fostering an immunosuppressive TME conducive to tumor growth. Notably, Prmt5 deletion induced PD-L1 expression on myeloid cells. Combining Prmt5 deletion with anti-PD-L1 therapy significantly enhanced antitumor efficacy, demonstrating a synergistic therapeutic effect.

CONCLUSIONS

These findings uncover a crucial role for PRMT5 in macrophage biology and suggest that targeting PRMT5 in myeloid cells offers a promising new approach for cancer immunotherapy. The combination of PRMT5 inhibition with anti-PD-L1 therapy may provide a potent strategy to reprogram the TME and enhance antitumor immune responses.

Tumor‑associated neutrophils: Critical regulators in cancer progression and therapeutic resistance (Review)

Cancer is the second leading cause of death among humans worldwide. Despite remarkable improvements in cancer therapies, drug resistance remains a significant challenge. The tumor microenvironment (TME) is intimately associated with therapeutic resistance. Tumor‑associated neutrophils (TANs) are a crucial component of the TME, which, along with other immune cells, play a role in tumorigenesis, development and metastasis. In the current review, the roles of TANs in the TME, as well as the mechanisms of neutrophil‑mediated resistance to cancer therapy, including immunotherapy, chemotherapy, radiotherapy and targeted therapy, were summarized. Furthermore, strategies for neutrophil therapy were discussed and TANs were explored as potential targets for cancer treatment. In conclusion, the need to explore the precise roles, recruitment pathways and mechanisms of action of TANs was highlighted for the purpose of developing therapies that precisely target TANs and reverse drug resistance.

Neutrophils in Type 1 Diabetes: Untangling the Intricate Web of Pathways and Hypothesis

Neutrophils are increasingly recognized as key contributors to the pathogenesis of Type 1 Diabetes (T1D), yet their precise mechanistic role in disease onset and progression remains incompletely understood. While these innate immune cells reside in pancreatic tissue and support tissue homeostasis under physiological conditions, they can also drive tissue damage by triggering innate immune responses and modulating inflammation. Within the inflammatory milieu, neutrophils establish complex, bidirectional interactions with various immune cells, including macrophages, dendritic cells, natural killer cells, and lymphocytes. Once activated, they may enhance the innate immune response through direct or indirect crosstalk with immune cells, antigen presentation, and β-cell destruction or dysfunction. These mechanisms underscore the multifaceted and dynamic role of neutrophils in T1D, shaped by their intricate immunological interactions. Further research into the diverse functional capabilities of neutrophils is crucial for uncovering novel aspects of their involvement in T1D, potentially revealing new therapeutic targets to modulate disease progression.

Immune cells differentiation in osteoarthritic cartilage damage: friends or foes?

Osteoarthritis (OA) is a chronic disease primarily characterized by degenerative changes in articular cartilage and synovitis, for which there are currently no targeted or curative therapies available in clinical practice. In recent years, the in-depth analysis of OA using single-cell sequencing and immunomics technologies has revealed the presence of multiple immune cell subsets, as well as different differentiation states within the same subset, in OA. Through immune-immune and immune-joint tissue interactions, these cells collectively promote or inhibit the progression of arthritis. This complex immune network, where "friends and foes coexist," has made targeted therapeutic strategies aimed at directly eliminating immune cells challenging, highlighting the urgent need for a detailed review of the composition, distribution, functional heterogeneity, therapeutic potential, and potential risks of immune subsets within the joint. Additionally, the similarities and differences between OA and rheumatoid arthritis (RA) in terms of diagnosis and immunotherapy need to be precisely understood, in order to draw lessons from or reject RA-based immunotherapies. To this end, this review summarizes the major triggers of inflammation in OA, the differentiation characteristics of key immune cell subsets, and compares the similarities and differences between OA and RA in diagnosis and treatment. It also outlines the current immunomodulatory strategies for OA and their limitations. Furthermore, we provide a detailed and focused discussion on immune cells that act as "friends or foes" in arthritis, covering the M1/M2 polarization of macrophages, functional heterogeneity of neutrophils, unique roles of dendritic cells at different maturation states, the balance between pro-inflammatory T cells and regulatory T cells (Tregs), and the diverse functions of B cells, plasma cells, and regulatory B cells (Bregs) in OA. By interpreting the roles of these immune cells, this review clarifies the dynamic changes and interactions of immune cells in OA joints, providing a theoretical foundation for more precise targeted interventions in future clinical practice.

Immunosuppressive JAG2+ tumor-associated neutrophils hamper PD-1 blockade response in ovarian cancer by mediating the differentiation of effector regulatory T cells

BACKGROUND

Tumor-associated neutrophils (TANs) play a critical role in modulating immune responses and exhibit significant heterogeneity. Our previous study demonstrated that jagged canonical Notch ligand 2 (JAG2)+ TANs were associated with an immunosuppressive microenvironment in high-grade serous ovarian cancer (HGSOC), but the underlying mechanism remains unclear. This study aimed to elucidate the role of JAG2+ TANs in tumor immunosuppressive microenvironment in HGSOC.

METHODS

HGSOC samples were collected, with 274 samples constituting two independent cohorts (training and validation cohorts) and an additional 30 samples utilized to establish patient-derived tumor organoids (PDTOs). We characterized the number and phenotype of JAG2+ TANs by multiplex immunohistochemistry, flow cytometry, and single-cell RNA sequencing (scRNA-seq). We investigated the biological functions of JAG2 in immune evasion using in vitro co-culture systems, flow cytometry, tumor-bearing mouse models, and PDTOs.

RESULTS

JAG2+ TANs expressed elevated levels of immunosuppressive molecules, including programmed cell death ligand 1 and CD14, and had independent prognostic value for the overall survival of patients with HGSOC. scRNA-seq analysis revealed that JAG2+ TANs exhibited a terminally mature phenotype. The infiltration of JAG2+ TANs was positively correlated with the abundance of effector regulatory T cells (eTregs). Interaction with JAG2+ TANs skewed CD4+ T cells towards an eTreg phenotype, a process that was suppressed by the Notch inhibitor LY3039478 and induced by recombinant Jagged2. Furthermore, we demonstrated that JAG2+ TANs enhanced Notch signaling activation, ultimately promoting recombination signal binding protein for immunoglobulin kappa J region (RBPJ)-induced differentiation of naïve CD4+ T cells into eTregs. Clinically, JAG2+ TANs could serve as a biomarker for assessing immunotherapy resistance in various solid tumors. Pharmacological targeting of Notch signaling with LY3039478 or JAG2 neutralization antibodies enhanced the efficacy of programmed cell death protein 1 (PD-1) monoclonal antibodies (mAbs) in both xenograft and PDTO models.

CONCLUSIONS

The emergence of JAG2+ TANs is crucial for the differentiation of eTregs, which triggers immune evasion and resistance to anti-PD-1 therapy. Inhibiting Notch signaling with LY3039478 or JAG2 neutralization antibodies may overcome this anti-PD-1 resistance in HGSOC.

Role of the oral-gut microbiota axis in pancreatic cancer: a new perspective on tumor pathophysiology, diagnosis, and treatment

Pancreatic cancer, one of the most lethal malignancies, remains challenging due to late diagnosis, aggressive progression, and therapeutic resistance. Recent advances have revealed the presence of intratumoral microbiota, predominantly originating from the oral and gut microbiomes, which play pivotal roles in pancreatic cancer pathogenesis. The dynamic interplay between oral and gut microbial communities, termed the "oral-gut microbiota axis," contributes multifacetedly to pancreatic ductal adenocarcinoma (PDAC). Microbial translocation via anatomical or circulatory routes establishes tumor-resident microbiota, driving oncogenesis through metabolic reprogramming, immune regulation, inhibition of apoptosis, chronic inflammation, and dysregulation of the cell cycle. Additionally, intratumoral microbiota promote chemoresistance and immune evasion, further complicating treatment outcomes. Emerging evidence highlights microbial signatures in saliva and fecal samples as promising non-invasive diagnostic biomarkers, while microbial diversity correlates with prognosis. Therapeutic strategies targeting this axis-such as antibiotics, probiotics, and engineered bacteria-demonstrate potential to enhance treatment efficacy. By integrating mechanisms of microbial influence on tumor biology, drug resistance, and therapeutic applications, the oral-gut microbiota axis emerges as a critical regulator of PDAC, offering novel perspectives for early detection, prognostic assessment, and microbiome-based therapeutic interventions.

Single-cell RNA sequencing revealed changes in the tumor microenvironment induced by radiotherapy for cervical cancer and the molecular mechanism of mast cells in immunosuppression

Radiotherapy (RT) is an important treatment for cervical cancer (CC), effectively controlling tumor growth and improving survival rates. However, radiotherapy-induced cell heterogeneity and its underlying mechanisms remain unclear, which may potentially impact treatment efficacy. This study aims to investigate tumor microenvironment changes following radiotherapy for CC, hoping to provide evidence to improve the therapeutic effects of radiotherapy. For the first time, we applied single-cell RNA sequencing (scRNA-seq) to analyze tissue samples from three CC patients pre- and post-radiotherapy. We obtained gene expression data from 52,506 cells to identify the cellular changes and molecular mechanisms induced by radiotherapy. Radiotherapy significantly alters cellular composition and gene expression within the tumor microenvironment (TME), notably upregulating mast cell expression. Mast cells are involved in multiple cell axes in the CC ecosystem after radiotherapy, and play a pivotal role in tumor immunosuppression and matrix remodeling. scRNA-seq revealed gene expression variations among cell types after radiotherapy, underscoring the importance of specific cell types in modulating the TME post-treatment. This study revealed the molecular mechanism of radiotherapy for CC and the role of mast cells, providing a foundation for optimizing the personalized treatment of CC.

Neutrophil plasticity in liver diseases

The liver has critical digestive, metabolic, and immunosurveillance roles, which get disrupted during liver diseases such as viral hepatitis, fatty liver disease, and hepatocellular carcinoma. While previous research on the pathological development of these diseases has focused on liver-resident immune populations, such as Kupffer cells, infiltrating immune cells responding to pathogens and disease also play crucial roles. Neutrophils are one such key population contributing to hepatic inflammation and disease progression. Belonging to the initial waves of immune response to threats, neutrophils suppress bacterial and viral spread during acute infections and have homeostasis-restoring functions, whereas during chronic insults, they display their plastic nature by responding to the inflammatory environment and develop new phenotypes alongside longer life spans. This review summarizes the diversity in neutrophil function and subpopulations present at steady state, during liver disease, and during liver cancer.

ADT-1004: a first-in-class, oral pan-RAS inhibitor with robust antitumor activity in preclinical models of pancreatic ductal adenocarcinoma

BACKGROUND

Oncogenic KRAS mutations occur in nearly, 90% of patients with pancreatic ductal adenocarcinoma (PDAC). Targeting KRAS has been complicated by mutational heterogeneity and rapid resistance. We developed a novel pan-RAS inhibitor, ADT-1004 (an oral prodrug of ADT-007) and evaluated antitumor activity in murine and human PDAC models.

METHODOLOGY

Murine PDAC cells with KRASG12D mutation (KPC-luc or 2838c3-luc) were orthotopically implanted into the pancreas of C57BL/6J mice, and four PDX PDAC tumors with KRAS mutations were implanted subcutaneously in NSG mice. To assess potential to overcome RAS inhibitor resistance, parental and resistant MIA PaCa-2 PDAC cells (KRASG12C mutation) were implanted subcutaneously. Subcutaneously implanted RASWT BxPC-3 cells were used to assess the selectivity of ADT-1004.

RESULTS

ADT-1004 potently blocked tumor growth and RAS activation in mouse PDAC models without discernable toxicity with target engagement and reduced activated RAS and ERK phosphorylation. In addition, ADT-1004 suppressed tumor growth in PDX PDAC models with KRASG12D, KRASG12V, KRASG12C, or KRASG13Q mutations and increased CD4+ and CD8+ T cells in the TME consistent with exhaustion and increased MHCII+ M1 macrophage and dendritic cells. ADT-1004 demonstrated superior efficacy over sotorasib and adagrasib in tumor models resistant to these KRASG12C inhibitors and MRTX1133 resistant KRASG12D mutant cells. As evidence of selectivity for tumors with mutant KRAS, ADT-1004 did not impact the growth of tumors from RASWT PDAC cells.

CONCLUSION/SIGNIFICANCE

ADT-1004 has strong antitumor activity in aggressive and clinically relevant PDAC models with unique selectivity to block RAS-mediated signaling in RAS mutant cells. As a pan-RAS inhibitor, ADT-1004 has broad activity and potential efficacy advantages over allele-specific KRAS inhibitors. These findings support clinical trials of ADT-1004 for KRAS mutant PDAC.

Pyruvate metabolism enzyme DLAT promotes tumorigenesis by suppressing leucine catabolism

Pyruvate and branched-chain amino acid (BCAA) metabolism are pivotal pathways in tumor progression, yet the intricate interplay between them and its implications for tumor progression remain elusive. Our research reveals that dihydrolipoamide S-acetyltransferase (DLAT), a pyruvate metabolism enzyme, promotes leucine accumulation and sustains mammalian target of rapamycin (mTOR) complex activation in hepatocellular carcinoma (HCC). Mechanistically, DLAT directly acetylates the K109 residue of AU RNA-binding methylglutaconyl-coenzyme A (CoA) hydratase (AUH), a critical enzyme in leucine catabolism, inhibiting its activity and leading to leucine accumulation. Notably, DLAT upregulation correlates with poor prognosis in patients with HCC. Therefore, we developed an AUHK109R-mRNA lipid nanoparticles (LNPs) therapeutic strategy, which effectively inhibits tumor growth by restoring leucine catabolism and inhibiting mTOR activation in vivo. In summary, our findings uncover DLAT's unexpected role as an acetyltransferase for AUH, suppressing leucine catabolism. Restoring leucine catabolism with AUHK109R-mRNA LNP effectively inhibits HCC development, highlighting a novel direction for cancer research.

Epigenetic regulation of iron metabolism and ferroptosis in Parkinson's disease: Identifying novel epigenetic targets

Parkinson's disease (PD) is a neurodegenerative disease, and emerging evidence has shown that iron deposition, ferroptosis and epigenetic modifications are implicated in the pathogenesis of PD. However, the interplay among these factors in PD has not been fully understood. In this review, we provide an overview of the current research progress on iron metabolism, ferroptosis and epigenetic alterations associated with PD. Furthermore, we present new frontiers concerning various epigenetic modifications related to iron metabolism and ferroptosis that might contribute to the pathology of PD. Notably, epigenetic modifications of iron metabolism and ferroptosis as both diagnostic and therapeutic targets in PD have been discussed. This opens new avenues for the regulation of iron homeostasis and ferroptosis in PD from epigenetic perspectives, and provides evidence for their potential implications in the diagnosis and treatment of PD.

Integrative analysis of single-cell and bulk RNA sequencing reveals the oncogenic role of ANXA5 in gastric cancer and its association with drug resistance

Background

Gastric cancer (GC) remains a leading cause of cancer-related mortality, with over one million new cases and 769,000 deaths reported in 2020. Despite advancements in chemotherapy, surgery, and targeted therapies, delayed diagnosis due to overlooked early symptoms leads to poor prognosis.

Methods

We integrated bulk RNA sequencing and single-cell RNA sequencing datasets from TCGA, GEO, and OMIX001073, employing normalization, batch effect correction, and dimensionality reduction methods to identify key cell populations associated with GC invasion and epithelial-mesenchymal transition (EMT), as well as analyze the tumor immune microenvironment.

Results

Our analysis identified the MUC5AC+ malignant epithelial cell cluster as a significant player in GC invasion and EMT. Cluster 1, representing this cell population, exhibited higher invasion and EMT scores compared to other clusters. Survival analysis showed that high abundance in cluster 0 correlated with improved survival rates (P=0.012), whereas cluster 1 was associated with poorer outcomes (P=0.045). A prognostic model highlighted ANXA5 and GABARAPL2 as two critical genes upregulated in GC tumors. High-risk patients demonstrated increased immune cell infiltration and worse prognosic. Analysis of tumor mutation burden (TMB) indicated that patients with low TMB in the high-risk group had the worst prognosis. Wet-lab validation experiments confirmed the oncogenic role of ANXA5, showing its facilitation of cell proliferation, invasion, and migration while suppressing apoptosis.

Conclusion

This study offers novel insights into the subpopulations of malignant epithelial cells in GC and their roles in tumor progression. It provides a prognostic model and potential therapeutic targets to combat GC, contributing crucial understanding to the fundamental mechanisms of drug resistance in gastrointestinal cancers.

Enhancer reprogramming: critical roles in cancer and promising therapeutic strategies

Transcriptional dysregulation is a hallmark of cancer initiation and progression, driven by genetic and epigenetic alterations. Enhancer reprogramming has emerged as a pivotal driver of carcinogenesis, with cancer cells often relying on aberrant transcriptional programs. The advent of high-throughput sequencing technologies has provided critical insights into enhancer reprogramming events and their role in malignancy. While targeting enhancers presents a promising therapeutic strategy, significant challenges remain. These include the off-target effects of enhancer-targeting technologies, the complexity and redundancy of enhancer networks, and the dynamic nature of enhancer reprogramming, which may contribute to therapeutic resistance. This review comprehensively encapsulates the structural attributes of enhancers, delineates the mechanisms underlying their dysregulation in malignant transformation, and evaluates the therapeutic opportunities and limitations associated with targeting enhancers in cancer.

Exploring Neutrophil Heterogeneity and Plasticity in Health and Disease

Neutrophils, the most abundant polymorphonuclear leukocytes, are critical first responders to infection, and have historically been underappreciated in terms of their functional complexity within the immune response. Once viewed primarily as short-lived, innate immune cells with limited functional plasticity, recent research has illuminated their considerable heterogeneity and diverse functional roles, which extend beyond their involvement in steady-state immunity. This review seeks to provide an updated analysis of neutrophil development, maturation, heterogeneity, and plasticity, with a focus on how these characteristics influence immune modulation in both healthy and diseased tissues. Beginning with the origin of neutrophils, we explore their maturation into effector cells and their evolving roles in immune defense under homeostatic and disease-associated conditions. We then delve into their heterogeneity, discussing recent breakthroughs in neutrophil research that challenge the traditional view of neutrophils as a uniform population. We address the significant advances that have been made in identifying distinct neutrophil subsets, the emerging complexities of their plasticity, and the challenges that remain in fully understanding their functional diversity. Finally, we highlight future directions and opportunities for continued exploration in this rapidly advancing field, shedding light on how these insights could open new avenues for therapeutic interventions.

Tumor Metastasis: Mechanistic Insights and Therapeutic Intervention

Metastasis remains a leading cause of cancer‐related deaths, defined by a complex, multi‐step process in which tumor cells spread and form secondary growths in distant tissues. Despite substantial progress in understanding metastasis, the molecular mechanisms driving this process and the development of effective therapies remain incompletely understood. Elucidating the molecular pathways governing metastasis is essential for the discovery of innovative therapeutic targets. The rapid advancements in sequencing technologies and the expansion of biological databases have significantly deepened our understanding of the molecular drivers of metastasis and associated drug resistance. This review focuses on the molecular drivers of metastasis, particularly the roles of genetic mutations, epigenetic changes, and post‐translational modifications in metastasis progression. We also examine how the tumor microenvironment influences metastatic behavior and explore emerging therapeutic strategies, including targeted therapies and immunotherapies. Finally, we discuss future research directions, stressing the importance of novel treatment approaches and personalized strategies to overcome metastasis and improve patient outcomes. By integrating contemporary insights into the molecular basis of metastasis and therapeutic innovation, this review provides a comprehensive framework to guide future research and clinical advancements in metastatic cancer.

Analyze the Diversity and Function of Immune Cells in the Tumor Microenvironment From the Perspective of Single-Cell RNA Sequencing

BACKGROUND

Cancer development is closely associated with complex alterations in the tumor microenvironment (TME). Among these, immune cells within the TME play a huge role in personalized tumor diagnosis and treatment.

OBJECTIVES

This review aims to summarize the diversity of immune cells in the TME, their impact on patient prognosis and treatment response, and the contributions of single-cell RNA sequencing (scRNA-seq) in understanding their functional heterogeneity.

METHODS

We analyzed recent studies utilizing scRNA-seq to investigate immune cell populations in the TME, focusing on their interactions and regulatory mechanisms.

RESULTS

ScRNA-seq reveals the functional heterogeneity of immune cells, enhances our understanding of their role in tumor antibody responses, and facilitates the construction of immune cell interaction networks. These insights provide guidance for the development of cancer immunotherapies and personalized treatment approaches.

CONCLUSION

Applying scRNA-seq to immune cell analysis in the TME offers a novel pathway for personalized cancer treatment. Despite its promise, several challenges remain, highlighting the need for further advancements to fully integrate scRNA-seq into clinical applications.

Metabolic reprogramming of neutrophils in the tumor microenvironment: Emerging therapeutic targets

Neutrophils are pivotal in the immune system and have been recognized as significant contributors to cancer development and progression. These cells undergo metabolic reprogramming in response to various stimulus, including infections, diseases, and the tumor microenvironment (TME). Under normal conditions, neutrophils primarily rely on aerobic glucose metabolism for energy production. However, within the TME featured by hypoxic and nutrient-deprived conditions, they shift to altered anaerobic glycolysis, lipid metabolism, mitochondrial metabolism and amino acid metabolism to perform their immunosuppressive functions and facilitate tumor progression. Targeting neutrophils within the TME is a promising therapeutic approach. Yet, focusing on their metabolic pathways presents a novel strategy to enhance cancer immunotherapy. This review synthesizes the current understanding of neutrophil metabolic reprogramming in the TME, with an emphasis on the underlying molecular mechanisms and signaling pathways. Studying neutrophil metabolism in the TME poses challenges, such as their short lifespan and the metabolic complexity of the environment, necessitating the development of advanced research methodologies. This review also discusses emerging solutions to these challenges. In conclusion, given their integral role in the TME, targeting the metabolic pathways of neutrophils could offer a promising avenue for cancer therapy.

Neutrophils in colorectal cancer: mechanisms, prognostic value, and therapeutic implications

Neutrophils, the most abundant myeloid cells in human peripheral blood, serve as the first defense line against infection and are also significantly involved in the initiation and progression of cancer. In colorectal cancer (CRC), neutrophils exhibit a dual function by promoting tumor events and exerting antitumor activity, which is related to the heterogeneity of neutrophils. The neutrophil extracellular traps (NETs), gut microbiota, and various cells within the tumor microenvironment (TME) are involved in shaping the heterogeneous function of neutrophils. This article provides an updated overview of the complex functions and underlying mechanisms of neutrophils in CRC and their pivotal role in guiding prognosis assessment and therapeutic strategies, aiming to offer novel insights into neutrophil-associated treatment approaches for CRC.

Yiqi Huayu Jiedu Decoction reduces colorectal cancer liver metastasis by promoting N1 neutrophil chemotaxis

Objective

To observe the inhibitory effect and potential mechanism of Yiqi Huayu Jiedu Decoction (YHJD) on liver metastasis of colorectal cancer (CRC).

Methods

We compared the changes of liver weight and liver index before and after YHJD treatment in CRC liver metastasis mouse models. HE staining was employed to observe the pathological changes in mouse liver tissue sections. Flow cytometry was used to analyze the number and marker of neutrophils treated with YHJD. Transcriptomics, proteomics, and multiplex cytokine array analyses were conducted to further verify the role of YHJD on CXCL1. Differential gene analysis was performed to further explore the mechanism by which YHJD inhibits liver metastasis of CRC.

Results

Animal studies demonstrated that YHJD reduces liver metastases. Flow cytometry results revealed that YHJD promotes N1 neutrophils in liver. Combining multi-omics and multiple cytokine arrays, we observed a significant increase in the expression of CXCL1 in the liver and plasma. GO and KEGG enrichment analyses indicated that YHJD may regulate the chemotaxis of neutrophils to inhibit the liver metastasis of CRC by participating in the regulation of cell adhesion molecule binding, adhesion protein binding, and multiple metabolic pathways.

Conclusions

YHJD inhibits CRC liver metastasis by upregulating CXCL1, thereby promoting N1 neutrophil chemotaxis towards the liver, and concurrently raising the expression of N1 neutrophil markers.

Sophisticated roles of tumor microenvironment in resistance to immune checkpoint blockade therapy in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) remains a serious threat to global health, with rising incidence and mortality rates. Therapeutic options for advanced HCC are quite limited, and the overall prognosis remains poor. Recent advancements in immunotherapy, particularly immune-checkpoint blockade (ICB) targeting anti-PD1/PD-L1 and anti-CTLA4, have facilitated a paradigm shift in cancer treatment, demonstrating substantial survival benefits across various cancer types, including HCC. However, only a subset of HCC patients exhibit a favorable response to ICB therapy, and its efficacy is often hindered by the development of resistance. There are many studies to explore the underlying mechanisms of ICB response. In this review, we compiled the latest progression in immunotherapies for HCC and systematically summarized the sophisticated mechanisms by which components of the tumor microenvironment (TME) regulate resistance to ICB therapy. Additionally, we also outlined some scientific rationale strategies to boost antitumor immunity and enhance the efficacy of ICB in HCC. These insights may serve as a roadmap for future research and help improve outcomes for HCC patients.

Combination therapy with lipid prodrug liposomes reshapes disease-associated neutrophils to promote the cancer-immunity cycle

Neutrophils play a critical role in the cancer-immunity cycle and are associated with poor clinical outcomes. Recent research has primarily focused on the targeted delivery, phenotypic reversal, and reprogramming of tumor-associated neutrophils, while the impact of disease-associated neutrophils (DANs) on antitumor therapy remains understudied. Since liposomes, as drug delivery carriers, possess excellent biocompatibility and stability, making them particularly suitable for combination therapy, we optimized the formulation of asymmetrically branched polyethylene glycol-modified mitomycin C lipid prodrug liposomes (PEG2,5 K@MLP-L) and prepared hyaluronic acid and sialic acid ester stearate-co-modified dexamethasone palmitate liposomes (HA*SAS@DXP-L) to study DANs in normal, obese, aged, and septic mice. An increase in mitochondria and lysosomes in Ly-6G+CXCR2high DANs accelerated drug clearance, reduced CD3+CD8+ T cell activity in tumor-draining lymph nodes, and decreased CD8+ T cell infiltration in tumors. As the proportion of DANs increased, the efficacy of PEG2,5 K@MLP-L decreased. Combination therapy with PEG2,5 K@MLP-L and HA*SAS@DXP-L can reshape DANs, promote the cancer-immunity cycle, and enhance treatment efficacy. This study identifies key characteristics and functions of DANs and presents a promising strategy for improving clinical outcomes.

Eliminating VEGFA+ tumor-associated neutrophils by antibody-drug conjugates boosts antitumor immunity and potentiates PD-1 immunotherapy in preclinical models of cervical cancer

Tumor-associated neutrophils (TANs) actively interact with antibody-drug conjugates (ADCs) within the tumor microenvironment (TME), though the detailed mechanisms governing their response to ADC treatment remain to be fully elucidated. Herein, we explored how ICAM1-targeted ADCs affect TAN dynamics in preclinical models of cervical cancer. We discovered that I-DXd, our in-house ADC targeting cervical cancer, effectively eliminates tumor cells through specific antigen recognition while concurrently depleting pro-tumor VEGFA + TANs via Fcγ receptor-mediated phagocytosis. This dual action promotes an immunologically favorable TME. Through comprehensive preclinical studies, we established a foundational understanding of the synergistic benefits of combining I-DXd treatment with PD-1 immune checkpoint inhibition, thereby opening new avenues for therapeutic intervention in advanced cervical cancer.

Harnessing amino acid pathways to influence myeloid cell function in tumor immunity

Amino acids are pivotal regulators of immune cell metabolism, signaling pathways, and gene expression. In myeloid cells, these processes underlie their functional plasticity, enabling shifts between pro-inflammatory, anti-inflammatory, pro-tumor, and anti-tumor activities. Within the tumor microenvironment, amino acid metabolism plays a crucial role in mediating the immunosuppressive functions of myeloid cells, contributing to tumor progression. This review delves into the mechanisms by which specific amino acids-glutamine, serine, arginine, and tryptophan-regulate myeloid cell function and polarization. Furthermore, we explore the therapeutic potential of targeting amino acid metabolism to enhance anti-tumor immunity, offering insights into novel strategies for cancer treatment.