Single-cell RNA-seq analysis reveals BHLHE40-driven pro-tumour neutrophils with hyperactivated glycolysis in pancreatic tumour microenvironment

Advances in Sampling and Analytical Techniques for Single-Cell Metabolomics: Exploring Cellular Heterogeneity

Single-cell metabolomics is an emerging and powerful technology that uncovers intercellular heterogeneity and reveals microenvironmental dynamics in both physiological and pathological conditions. This technology enables detailed observations of cellular interactions, providing valuable insights into processes such as aging, immune responses, and disease development. Despite significant advances, the need for detailed discussions on sampling and analytical methods in single-cell metabolomics continues to grow, with increasing focus on selecting the most suitable techniques for diverse research objectives. This review addresses these challenges by exploring key sampling and analytical strategies used in single-cell metabolomics. We focus on three main approaches: the capture and isolation of specific cell types, the precise aspiration of individual cells, and in situ mass spectrometry imaging. These methods are critically assessed to highlight strategies for achieving accurate metabolite detection at the single-cell level across diverse research applications.

Integrated analysis of scRNA-seq and bulk RNA-seq data identifies BHLHE40 as a key gene in pancreatic cancer progression and gemcitabine resistance

OBJECTIVE

Pancreatic cancer is characterized by its high mortality rate and short survival periods, and novel therapeutic targets and tailor personalized strategies are urgently needed. In this study, we aim to investigate the molecular mechanisms underlying pancreatic ductal adenocarcinoma (PDAC) progression and chemoresistance, with a focus on identifying novel therapeutic targets.

METHODS

Multiomics approaches were integrated to identify novel actionable targets for PDAC. Public datasets such as TCGA and GEO were utilized to investigate the relationship between gene expression and clinical outcomes. Functional enrichment, cell-cell communication, and metabolic pathway analyses were performed to reveal PDAC heterogeneity and therapeutic resistance mechanisms.

RESULTS

BHLHE40 was identified as a hub gene linked to high-CNV PDAC cells, Gemcitabine resistance, and poor prognosis in PDAC. High BHLHE40 expression is significantly correlated with immunosuppressive tumor microenvironment (TME) features such as reduced CD8+ T infiltration, TCR richness, and lower tumor mutational burden (TMB). ChIP-seq data analysis confirmed BHLHE40 could directly bind to the SAT1 promoter, establishing a transcriptional axis promoting chemoresistance. Single-cell RNA-seq analysis further revealed that the BHLHE40+/SAT1+ subpopulation cells are resistant to Gemcitabine in PDAC.

CONCLUSIONS

BHLHE40 is significantly correlated with PDAC malignancy and chemoresistance via SAT1 regulation and immune evasion. Targeting BHLHE40 may sensitize PDACs to Gemcitabine and facilitate personalized treatment for BHLHE40+ PDAC patients.

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.

Targeting lactylation and the STAT3/CCL2 axis to overcome immunotherapy resistance in pancreatic ductal adenocarcinoma

Metabolic reprogramming in pancreatic ductal adenocarcinoma (PDAC) fosters an immunosuppressive tumor microenvironment (TME) characterized by elevated lactate levels, which contribute to immune evasion and therapeutic resistance. In this issue of the JCI, Sun, Zhang, and colleagues identified nonhistone ENSA-K63 lactylation as a critical regulator that inactivates PP2A, activates STAT3/CCL2 signaling, recruits tumor-associated macrophages (TAMs), and suppresses cytotoxic T cell activity. Targeting ENSA-K63 lactylation or CCL2/CCR2 signaling reprograms the TME and enhances the efficacy of immune checkpoint blockade (ICB) in PDAC preclinical models. This work provides critical insights into the metabolic-immune crosstalk in PDAC and highlights promising therapeutic strategies for overcoming immune resistance and improving patient outcomes.

CTCF enhances pancreatic cancer progression via FLG-AS1-dependent epigenetic regulation and macrophage polarization

CCCTC-binding factor (CTCF) regulates chromatin organization and is upregulated in pancreatic ductal adenocarcinoma (PDAC). We found that CTCF interacts with HNRNPU through a FLG-AS1-dependent mechanism, facilitating the recruitment of EP300 and activation of the m6A reader IGF2BP2. This activation promotes histone lactylation at the promoter region of IGF2BP2 stimulating the proliferation of PDAC cells. IGF2BP2 enhanced the mRNA stability of CSF1 and MYC. Moreover, FLG-AS1 directly interacts with HNRNPU to modulate alternative splicing of CSF1, thus promoting the M2 polarization of tumor associated macrophages (TAMs) in PDAC. The results indicated that CTCF-induced oncogenic modification of histone lactylation, m6A and alternative spilcing as multi-regulation modes of TAMs reprogramming in PDAC and identifies CTCF as a potential therapeutic target for PDAC immunotherapy whose inhibition M2 polarization through the IGF2BP2/CSF1/CSF1R axis. Curaxin combined with gemcitabine treatment has shown promising antitumor efficacy against PDAC.

Single-Cell Transcriptomes of Immune Cells from Multiple Compartments Redefine the Ontology of Myeloid Subtypes Post-Stroke

The activation and infiltration of immune cells are hallmarks of ischemic stroke. However, the precise origins and the molecular alterations of these infiltrating cells post-stroke remain poorly characterized. Here, a murine model of stroke (permanent middle cerebral artery occlusion [p-MCAO]) is utilized to profile single-cell transcriptomes of immune cells in the brain and their potential origins, including the calvarial bone marrow (CBM), femur bone marrow (FBM), and peripheral blood mononuclear cells (PBMCs). This analysis reveals transcriptomically distinct populations of cerebral myeloid cells and brain-resident immune cells after stroke. These include a novel CD14+ neutrophil subpopulation that transcriptomically resembles CBM neutrophils. Moreover, the sequential activation of transcription factor regulatory networks in neutrophils during stroke progression is delineated, many of which are unique to the CD14+ population and underlie their acquisition of chemotaxis and granule release capacities. Two distinct origins of post-stroke disease-related immune cell subtypes are also identified: disease inflammatory macrophages, likely deriving from circulating monocytes in the skull, and transcriptionally immature disease-associated microglia, possibly arising from pre-existing homeostatic microglia. Together, a comprehensive molecular survey of post-stroke immune responses is performed, encompassing both local and distant bone marrow sites and peripheral blood.

Glycolysis-related gene signatures and the functional role of P4HA1 in osteosarcoma prognosis

Osteosarcoma, a primary malignant bone tumor predominantly affecting children and adolescents, is characterized by aerobic glycolysis, which is intricately linked to tumor progression and metastasis, yet its prognostic implications remain underexplored. This study aimed to develop a prognostic model utilizing glycolysis-related genes and to elucidate the functional role of P4HA1, a key gene within this model, in osteosarcoma prognosis and immune cell infiltration. We collected clinical and transcriptomic data from osteosarcoma patients in the UCSC Xena and GEO databases. Through univariate Cox and LASSO regression analyses, we identified 12 glycolysis-related genes that significantly influence osteosarcoma prognosis. These genes were employed to construct a risk score model, which accurately predicted patient outcomes as demonstrated by survival analysis and ROC curves, with an AUC of 0.899, 0.881, and 0.878 for 1-year, 3-year, and 5-year survival predictions, respectively. The model was particularly effective across different clinical subgroups. Immune cell infiltration analysis revealed that CD8+ T cells, naïve CD4+ T cells, resting dendritic cells, and activated mast cells significantly contributed to the model's predictive power. The model also showed significant enrichment of immune-related signaling pathways, indicating a robust association between immune status and glycolytic-related risk scores in osteosarcoma prognosis. Notably, P4HA1 was upregulated in osteosarcoma tissues and promoted cell proliferation in a glycolysis-dependent manner, as evidenced by increased intracellular ATP levels, inhibited glucose absorption, and elevated lactate levels in P4HA1-overexpressing osteosarcoma cells. The promotion of proliferation by P4HA1 could be significantly attenuated by the glycolysis inhibitor 2-DG, highlighting the glycolysis dependency of P4HA1's action. In conclusion, we developed a prognostic model for osteosarcoma by integrating glycolysis-related genes, with a particular emphasis on the functional role of P4HA1. Our findings highlight the interplay between glycolysis and immune cell infiltration in disease prognosis. This model provides insights for targeted therapies and a foundation for further research into osteosarcoma treatment.

Myeloid cells are involved in tumor immunity, metastasis and metabolism in tumor microenvironment

Bone marrow-derived cells in the tumor microenvironment, including macrophages, neutrophils, dendritic cells, myeloid-derived suppressor cells, eosinophils and basophils, participate in the generation, development, invasion and metastasis of tumors by producing different cytokines and interacting with other cell types, and play a pro-tumor or anti-tumor role in regulating tumor immunity. Due to the complexity of cell types in the tumor microenvironment and the unknown process of tumor development and metastasis, cancer treatment to achieve better survival status remains challenging. In this article, we summarize the effects of myeloid cells in tumor microenvironment on tumor immunity, cancer migration, and crosstalk with metabolism (including glucose metabolism, lipid metabolism, and amino acid metabolism), which will help to further study the tumor microenvironment and seek targeted therapeutic strategies for patients.

GLI2 inhibits cisplatin sensitivity in gastric cancer through DEC1/ZEB1 mediated EMT

Cisplatin (CDDP) based chemotherapy has emerged as the predominant therapeutic regimen for patients with advanced gastric cancer (GC). However, its efficacy is dampened by the development of chemoresistance, which results in poor prognosis of patients. GLI2, a key transcription factor in the Hedgehog (Hh) signaling pathway, is regarded as a target for cancer therapy. However, the significance of GLI2 for CDDP resistance in GC has not been well established. Here, we show that GLI2 expression was upregulated in EMT-type GC and associated with poor prognosis. GLI2 promotes proliferation, migration, and CDDP resistance of GC cells by inducing EMT. In terms of mechanism, GLI2 binds to the promoter region of DEC1 and enhances its expression, thereby co-transcriptionally regulating ZEB1 expression. Animal experiments have demonstrated that both GLI2 knockdown and GLI2 inhibitor significantly enhance CDDP sensitivity in GC. Our data not only identify a novel GLI2/DEC1/ZEB1/EMT pathway in GC CDDP resistance but also provide novel strategies to treat GC in the future.

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.

Near-Infrared Imaging Agent ABSi-148 Alleviates CA IX-Mediated Hypoxic Fibrosis in Inflammation-Cancer Transition

Pancreatic ductal adenocarcinoma (PDAC) remains a formidable challenge due to its late diagnosis and intrinsic treatment resistance, exacerbates by its development from chronic inflammation to cancer transition (ICT). Here, this investigation aims to develop and evaluate ABSi-148, a novel near-infrared (NIR) agent targeting hypoxic carbonic anhydrase IX (CA IX), for its potential applications in ICT imaging and even PDAC treatment. ABSi-148 is synthesized from 4-(2-Aminoethyl) benzene sulfonamide (ABS), a sulfonamide derivative, conjugating with MHI-148 dye with merits of exceptional NIR-emitting traits, high biocompatibility, and deep tissue penetration imaging capability. It selectively accumulates in CoCl2-induced pancreatic stellate cells and pancreatic cancer cells via binding with transmembrane CA IX in vitro. Meanwhile, ABSi-148 effectively visualizes the early pancreatic lesion, and its long-term administration inhibits the progression of hypoxia-related fibrosis involved in pancreatic intraepithelial neoplasias (PanINs), and even PDAC progression in vivo. Besides, ABSi-148 monitors treatment efficacy and localizes hypoxic tumor regions, enhancing survival in tamoxifen combined with caerulein-induced KPC mice. Overall, ABSi-148 emerges as a theranostic NIR agent for precise diagnosis and targeted therapy in ICT of PDAC, promising to alleviate tumor progression and enhancing outcomes.

Global trends in tumor-associated neutrophil research: a bibliometric and visual analysis

Background

Tumor-associated neutrophils (TANs) play crucial roles in tumor progression, immune response modulation, and the therapeutic outcomes. Despite significant advancements in TAN research, a comprehensive bibliometric analysis that objectively presents the current status and trends in this field is lacking. This study aims to fill this gap by visually analyzing global trends in TANs research using bibliometric and knowledge mapping techniques.

Methods

We retrieved articles and reviews related to TANs from the Web of Science core collection database, spanning the period from 2012 to2024. The data was analyzed using bibliometric tools such as Excel 365, CiteSpace, VOSviewer, and Bibliometrix (R-Tool of R-Studio) to identify key trends, influential countries and institutions, collaborative networks. and citation patterns.

Results

A total of 6l5 publications were included in the bibliometric analysis, showing a significant upward trend in TANs research over the last two decades. The United States and China emerged as the leading contributors with the highest number of publications and citations. The journal with the most publications in this field is Frontiers in Immunology, Prominent authors such as Fridlender ZG was identified as the key contributor, with his works frequently cited. The analysis highlighted major research themes. including the role of TANs in tumor microenvironment modulation, their dual functions in tumor promotion and suppression, and the exploration of TANs-targeted therapies, Emerging research hotspots include studies on TANs plasticity and their interactions with other immune cells.

Conclusion

This study is the first to employ bibliometric methods to visualize trends and frontiers in TANs research. The findings provide valuable insights into the evolution of the field, highlighting critical areas for future investigation and potential collaborative opportunities. This comprehensive analysis serves as a crucial resource for researchers and practitioners aiming to advance TAN research and its application in cancer therapy.

Microbiome dysbiosis, neutrophil recruitment and mesenchymal transition of mesothelial cells promotes peritoneal metastasis of colorectal cancer

Peritoneal metastasis (PM) is common in colorectal cancer (CRC), yet its underlying mechanisms are poorly understood. Here, we explored the transcriptional profile of CRC, PM and adjacent tissues revealing key players that facilitate PM. Single-cell analysis of 48 matched samples from 12 patients revealed that remodeling of malignant cells and the tumor microenvironment promotes CRC progression and metastasis. Multiplexed imaging confirmed depletion in PM by enrichment in CRC tissues of neutrophils associated with mucosal immunity disruption, intestinal microbiota dysbiosis and mesenchymal transition of both cancerous and mesothelial cells. Functional analyses in cell lines, organoids and in vivo models demonstrated that dysbiosis promoted inflammation and protumor neutrophil recruitment, while coupled mesenchymal transition of malignant and mesothelial cells disrupted the stromal structure and increased cancer cell invasiveness. Our findings suggest that targeting mesothelial cells and tumor microenvironment remodeling may offer therapeutic strategies for CRC-PM.

Characteristics of the Dynamic Evolutionary Pathway of ADSCs Induced Differentiation into Astrocytes Based on scRNA-Seq Analysis

We employed single-cell transcriptome sequencing to reveal the dynamic gene expression changes during the differentiation of adipose-derived stromal cells (ADSCs) into astrocytes. Single-cell RNA sequencing was conducted on cells from the ADSCs group and the induced groups at 2, 7, 14, and 21 days using the 10 × Chromium platform. Data underwent quality control and dimensionality reduction. Cell differentiation trajectories were constructed using Monocle2, and differentially expressed genes (DEGs) in each cell cluster were identified using differential selection algorithms. DEGs at each time point were annotated using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG), and regulatory intensities of transcription factors were analyzed using SCENIC. Integrating all groups, a total of five samples were divided into 13 cell clusters (0-12 clusters). DEGs between clusters and those compared with ADSCs at various induced time points showed distinct specificities. Monocle2 constructed cell differentiation trajectories; ADSCs can differentiate into mature astrocytes not only through the direct pathway from the 1 branch to the 3 branch but also through an indirect pathway, involving the 1 branch to the 2 branch before progressing to the 3 branch. SCENIC analysis highlighted the critical regulatory roles of STAT1, MYEF2, and SOX6 transcription factors during the differentiation of ADSCs into astrocytes. ADSCs can differentiate into mature astrocytes through two distinct pathways: direct and indirect. By the 14th day of induction, mature astrocytes have formed, characterized by a cell cycle arrest in mitosis. Further induction leads to degenerative senescence changes in differentiated cells.

Single-cell transcriptomics reveals intratumor heterogeneity and the potential roles of cancer stem cells and myCAFs in colorectal cancer liver metastasis and recurrence

Metastasis and recurrence are the primary obstacles to long-term survival in colorectal cancer (CRC) patients. In this study, we employed single-cell RNA sequencing (scRNA-seq) to comprehensively delineate the transcriptomic landscape of primary and liver metastatic CRCs, and revealed novel cellular crosstalk between cancer cell subpopulation and myofibroblastic CAFs (myCAFs) at single-cell resolution. We identified a cancer cell subpopulation termed stem/transient amplifying-like (stem/TA-like) cells, which expressed genes associated with stem cell-like characteristics and metastatic potential. MyCAFs in their microenvironment showed the potential to remodel the extracellular matrix (ECM), regulate angiogenesis, and support a pro-metastatic microenvironment through paracrine signaling involving FN1, BGN, and other ECM components. Notably, we found that they may communicate through the ligand-receptor pairs FN1-CD44 and GDF15-TGFBR2, which may be linked to the liver metastatic process. Additionally, our findings suggest that both stem/TA-like cells and myCAFs could be involved in CRC recurrence following chemotherapy. A unique gene signature generated using the gene expression characteristics of stem/TA-like cells and myCAFs (SM signature) can be used to assess recurrence risk in CRC patients. Collectively, these findings highlight the intratumor heterogeneity and the potential roles of cancer stem cells and myCAFs in CRC liver metastasis and recurrence, providing new targets and insights for the prognostic assessment of CRC patients and the improved selection of effective treatment options.

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.

Therapeutic implications of endoplasmic reticulum stress gene CCL3 in cervical squamous cell carcinoma

This study investigated ERS-related gene expressions in CESC, identifying two molecular subtypes, P1 and P2, and constructing a precise prognostic model based on these subtypes. TCGA's whole-genome expression profiles were used to recognize these subtypes through the ConsensusClusterPlus method, further refining prognostic models with univariate and Lasso Cox regression analyses validated by the GSE39001 dataset. The study analyzed the expression distribution of ERS marker genes within T cell subgroups using scRNA-seq data (GSE168652), highlighting T cell diversity. The critical role of the CCL3 gene in prognostic models was examined explicitly in CD8 + T cells from healthy individuals and CESC patients. Elevated CCL3 levels were observed in patients' CD8 + T cells compared to healthy controls. Functional experiments involving CCL3 knockdown and overexpression in HeLa and SiHa CESC cell lines were conducted to investigate its impact on cell proliferation, migration, and invasion. These findings were subsequently validated in a nude mouse model. The results demonstrated that suppressing CCL3 inhibited cell proliferation, migration, and invasion significantly, while its overexpression promoted these processes. In the mouse model, CCL3 silencing reduced tumor growth and decreased Ki-67 labeling within the tumor tissues, indicating the therapeutic potential of targeting CCL3 in CESC treatment, possibly through CD8 + T cell regulation. This study contributes new prognostic assessment tools and personalized treatment options for CESC patients, paving the way for more targeted therapies in CESC by discovering the CCL3 gene, presenting significant clinical implications.

WNT inhibitor SP5-mediated SERPING1 suppresses lung adenocarcinoma progression via TSC2/mTOR pathway

The long-term outlook for patients grappling with lung cancer (LC) remains bleak, with lung adenocarcinoma (LUAD) emerging as the most predominant histological subtype. Our Mendelian randomization (MR) investigation spotlighted that heightened levels of the circulating protein serpin peptidase inhibitor family G1 (SERPING1) substantially mitigated LC risk. The fusion of multi-omics strategies unveiled that SERPING1 exhibited diminished expression in LUAD patients compared to healthy individuals both in tissues and serum, with LUAD individuals showcasing elevated SERPING1 expression demonstrating improved prognoses. Furthermore, SERPING1 expression exhibited a robust correlation with the efficacy of immunotherapy. Through meticulous in vivo and in vitro analyses, we unraveled that SERPING1 impeded the proliferation, migration, invasion and wound healing of LUAD cells via the tuberous sclerosis 2 (TSC2)/mammalian target of rapamycin (mTOR) pathway. Mechanistically, WNT inhibitor- Specificity Protein (SP5) was delineated as facilitator of SERPING1 transcription by binding to the SERPING1 gene promoter. Intriguingly, aside from the association between SERPING1 and systolic blood pressure, glycosylated hemoglobin (HbA1c), type I diabetes, no discernible link between SERPING1 overexpression and heightened risks of other cardiometabolic conditions and diseases was evident. In summary, SERPING1 emerges as a novel tumor suppressor gene and SP5/SERPING1/TSC2 is a promising therapeutic target in the context of LUAD.

Long non-coding RNAs: Emerging regulators of invasion and metastasis in pancreatic cancer

BACKGROUND

The invasion and metastasis of pancreatic cancer (PC) are key factors contributing to disease progression and poor prognosis. This process is primarily driven by EMT, which has been the focus of recent studies highlighting the role of long non-coding RNAs (lncRNAs) as crucial regulators of EMT. However, the mechanisms by which lncRNAs influence invasive metastasis are multifaceted, extending beyond EMT regulation alone.

AIM OF REVIEW

This review primarily aims to characterize lncRNAs affecting invasion and metastasis in pancreatic cancer. We summarize the regulatory roles of lncRNAs across multiple molecular pathways and highlight their translational potential, considering the implications for clinical applications in diagnostics and therapeutics.

KEY SCIENTIFIC CONCEPTS OF REVIEW

The review focuses on three principal scientific themes. First, we primarily summarize lncRNAs orchestrate various signaling pathways, such as TGF-β/Smad, Wnt/β-catenin, and Notch, to regulate molecular changes associated with EMT, thereby enhancing cellular motility and invasivenes. Second, we summarize the effects of lncRNAs on autophagy and ferroptosis and discuss the role of exosomal lncRNAs in the tumor microenvironment to regulate the behavior of neighboring cells and promote cancer cell invasion. Third, we emphasize the effects of RNA modifications (such as m6A and m5C methylation) on stabilizing lncRNAs and enhancing their capacity to mediate invasive metastasis in PC. Lastly, we discuss the translational potential of these findings, emphasizing the inherent challenges in using lncRNAs as clinical biomarkers and therapeutic targets, while proposing prospective research strategies.

Novel anti-inflammatory properties of mannose oligosaccharides in the treatment of inflammatory bowel disease via LGALS3 modulation

This study investigates the role of Gum Arabic Mannose Oligosaccharides (GA-MOS) in modulating gut microbiota and alleviating symptoms of Inflammatory Bowel Disease (IBD). Employing both in vitro and in vivo models, we explored how GA-MOS influences microbial communities, particularly focusing on their capacity to enhance health-associated bacteria and reduce pathogenic species within the gut environment. Our findings reveal that GA-MOS treatment significantly altered the gut microbiota composition, increasing the abundance of anti-inflammatory bacteria while decreasing pro-inflammatory species, thus contributing to a reduction in gut inflammation and an improvement in intestinal barrier function. Detailed molecular analyses further demonstrated that these changes in microbiota were associated with modifications in the host's immune response, particularly through the suppression of key inflammatory pathways and cytokines involved in IBD progression. These results underscore the potential of dietary polysaccharides like GA-MOS as therapeutic agents in managing dysbiosis and inflammatory conditions in the gut, offering a promising approach for enhancing microbial health and overall disease management in IBD. This study provides novel insights into the bioactive properties of MOS and their interactions with gut microbiota, suggesting broader implications for their use in microbiome-centered therapies.

Integration of single-cell and bulk RNA-sequencing data to construct and validate a signature based on NK cell marker genes to predict immunotherapy response and prognosis in colorectal cancer

We aimed to create a NK cell marker genes-based signature to predict immunotherapy response and prognosis in colorectal cancer. We integrated scRNA-seq data from four Gene Expression Omnibus (GEO) samples and performed Weighted gene correlation network analysis (WGCNA) based on 587 the Cancer Genome Atlas (TCGA) colorectal cancer samples to uncover NK cell-related genes. We identified 1080 NK cell-related core genes and 276 NK cell-related feature genes based on WGCNA and clustering and annotation of scRNA-seq data, respectively. Six key NK cell-related prognostic signature genes were obtained by univariate and LASSO regression analyses, including ADAM8, CTSD, CCL4, IL2RB, TTC38, and PLEK. Two validation cohorts from the GEO dataset, comprising 124 and 201 samples respectively, were used. The signature was significantly associated with overall survival and correlated with immune cell infiltration, immune and stromal scores, and immune checkpoint genes. Furthermore, the signature was associated with the homologous recombination deficiency (HRD) and T-cell receptor (TCR) scores. In conclusion, our study proposes a new prognostic signature based on NK cell marker genes, which may serve as a potential tool to predict overall survival and immunotherapy response for CRC patients.

Tumor-derived exosomes induce neutrophil infiltration and reprogramming to promote T-cell exhaustion in hepatocellular carcinoma

Rationale: High neutrophil infiltration in hepatocellular carcinoma (HCC) is associated with a poor prognosis in patients with HCC. Tumor-derived exosomes (TDEs) have been proven to be important in the reprogramming of tumor-associated neutrophils (TANs), but the roles and mechanisms have not been fully clarified. Methods: The roles of HCC-exosome-reprogrammed neutrophils on tumor progression were evaluated in the DEN/CCl4-induced HCC mouse model by blocking neutrophil infiltration, depleting neutrophil, and neutrophil adoptive transfer. Transcriptome sequencing and flow cytometry were performed to investigate the effects of HCC exosomes on the phenotype and function of neutrophils. The mobilization and apoptosis of neutrophils were evaluated by the Transwell experiment and Annexin V/7-AAD staining, respectively. Moreover, we detected the effects of HCC-exosome-reprogrammed neutrophils on T cells by flow cytometry. Next, we used the NF-κB pathway inhibitor JSH-23 and miR-362-5p inhibitor or mimic to determine the molecular mechanisms. Lastly, we constructed the miR-362-5p sponge to validate its targeted therapeutic potential. Results: We found that HCC exosomes induced neutrophil infiltration and T-cell exhaustion in the livers of DEN/CCl4-induced HCC mice and promoted tumor progression. Blocking neutrophil infiltration and depleting neutrophils diminished these promotive effects of HCC exosomes. In addition, HCC exosome-reprogrammed neutrophils display proinflammatory and protumor phenotypes, and can directly induce T-cell exhaustion in vitro. The transfer of HCC exosome-reprogrammed neutrophils exacerbated tumor progression and induced T-cell exhaustion, as evidenced by the downregulation of IFN-γ and TNF-α, and the upregulation of PD-1 and Tim3 in T cells. Mechanistically, we found that HCC exosomes upregulate the expression of miR-362-5p in neutrophils and activate the NF-κB signaling pathway by targeting CYLD, promoting the survival and recruitment of neutrophils. In HCC mice, blocking miR-362-5p suppressed neutrophil infiltration, attenuated T-cell exhaustion, and suppressed HCC progression. Conclusions: This study clarified the roles of HCC exosomes on neutrophil infiltration and reprogramming and identified a potential target miR-362-5p for HCC treatment.

CXCL16/CXCR6/TGF-β Feedback Loop Between M-MDSCs and Treg Inhibits Anti-Bacterial Immunity During Biofilm Infection

Staphylococcus aureus (S. aureus) is a leading cause of Periprosthetic  joint  infection (PJI), a severe complication after joint arthroplasty. Immunosuppression is a major factor contributing to the infection chronicity of S. aureus PJI, posing significant treatment challenges. This study investigates the relationship between the immunosuppressive biofilm milieu and S. aureus PJI outcomes in both discovery and validation cohorts. This scRNA-seq analysis of synovium from PJI patients reveals an expansion and heightened activity of monocyte-related myeloid-derived suppressor cells (M-MDSCs) and regulatory T cells (Treg). Importantly, CXCL16 is significantly upregulated in M-MDSCs, with its corresponding CXCR6 receptor also elevated on Treg. M-MDSCs recruit Treg and enhance its activity via CXCL16-CXCR6 interactions, while Treg secretes TGF-β, inducing M-MDSCs proliferation and immunosuppressive activity. Interfering with this cross-talk in vivo using Treg-specific CXCR6 knockout PJI mouse model reduces M-MDSCs/Treg-mediated immunosuppression and alleviates bacterial burden. Immunohistochemistry and recurrence analysis show that PJI patients with CXCR6high synovium have poor prognosis. This findings highlight the critical role of CXCR6 in Treg in orchestrating an immunosuppressive microenvironment and biofilm persistence during PJI, offering potential targets for therapeutic intervention.

KMO-driven metabolic reconfiguration and its impact on immune cell infiltration in nasopharyngeal carcinoma: a new avenue for immunotherapy

BACKGROUND

Nasopharyngeal carcinoma (NPC), a malignant epithelial tumor, is characterized by a complex tumor microenvironment (TME) and closely associated with metabolic dysfunction. Mitochondrial metabolism plays a crucial role in supporting the rapid proliferation of tumor cells. However, the specific response of mitochondria to the NPC microenvironment and their role in regulating the metabolic heterogeneity of the tumor remain poorly understood.

METHODS

Tissue samples and corresponding clinicopathological data were collected from 72 primary NPC patients and 36 non-tumor controls. Histological analysis, coupled with public transcriptomic database interrogation, was utilized to investigate mitochondrial dynamics and metabolism across different cell types. Characterizing the interactions within the tumor-immune microenvironment (TME), we identified mitochondrial genes associated with prognosis in NPC. Additionally, we explored the relationship between key mitochondrial genes, the TME, and the response to immunotherapy.

RESULTS

Malignant epithelial cells in NPC exhibited altered mitochondrial metabolism, including dysregulation of amino acid and glucose metabolism, when compared to non-malignant cells. The mitochondrial-related hub gene KMO was significantly downregulated in NPC tissues relative to normal controls. Low expression of KMO was associated with poorer survival outcomes in patients. Furthermore, KMO expression was negatively correlated with DNA repair mechanisms and hypoxia. In addition, KMO levels were inversely associated with the upregulation of both oxidative phosphorylation (OXPHOS) and glycolysis pathways within the NPC tumor microenvironment (TME). Single-cell transcriptomic analysis revealed that KMO was primarily expressed in B cells, with some contribution from myeloid cells. Importantly, KMO levels positively correlated with the infiltration of various immune cell populations, including B cells, T cells, and macrophages, as well as inflammatory signatures. Further investigation indicated that individuals with elevated KMO expression may exhibit heightened sensitivity to immune checkpoint blockade (ICB) therapy compared to those with lower KMO expression.

CONCLUSION

The mitochondrial hub gene KMO plays a pivotal role in regulating mitochondrial metabolism and modulating the immune microenvironment in NPC. As a potential prognostic biomarker, KMO may offer valuable predictive insights, and targeting KMO could represent a promising therapeutic strategy for NPC, potentially enhancing the efficacy of immunotherapies.

Adaptations of neutrophils in cancer

There is a renewed interest in neutrophil biology, largely instigated by their prominence in cancer. From an immunologist's perspective, a conceptual breakthrough is the realization that prototypical inflammatory, cytotoxic leukocytes can be tamed to promote the survival and growth of other cells. This has sparked interest in defining the biological principles and molecular mechanisms driving the adaptation of neutrophils to cancer. Yet, many questions remain: is this adaptation mediated by reprogramming mature neutrophils inside the tumoral mass, or rather by rewiring granulopoiesis in the bone marrow? Why, in some instances, are neutrophils beneficial and in others detrimental to cancer? How many different functional programs can be induced in neutrophils by tumors, and is this dependent on the type of tumor? This review summarizes what we know about these questions and discusses therapeutic strategies based on our incipient knowledge of how neutrophils adapt to cancer.

Revisiting of Cancer Immunotherapy: Insight from the Dialogue between Glycolysis and PD-1/PD-L1 Axis in the Tumor Microenvironment

The interplay between metabolic pathways and immune escape has emerged as a captivating research area in oncobiology. Among these, the Warburg effect stands out as a hallmark metabolic reprogramming in cancer, characterized by elevated glucose utilization and excessive lactic acid production through anaerobic glycolysis. Key glycolytic enzymes not only fulfill the bioenergetic demands of cancer cells but also exhibit moonlighting roles, including regulation of epigenetic modifications, protein kinase activity, and immune escape mechanisms, thereby reshaping the tumor microenvironment. Tumor-specific vascular architecture facilitates lactate accumulation, which drives tumor progression by impairing immune cell function and acting as a signaling molecule to recruit immunosuppressive cells and modulate immune checkpoint pathways. The PD-1/PD-L1 co-stimulatory pathway plays a crucial role in negatively modulating the activation, proliferation, and cytokine secretion by T-lymphocytes. This review primarily focuses on elucidating the regulation and mechanisms underlying PD-1/PD-L1 signaling axis during glycolysis in tumor cells as well as surrounding cells. In the era of precision medicine, there is a particular interest in leveraging 18F-FDG PET/CT imaging as a valuable tool to assess PD-L1 expression status for more targeted therapeutic interventions. Additionally, the development of natural compounds capable of modulating metabolism opens new avenues for metabolism-based immunotherapy, though further studies are required to validate their in vivo efficacy.

Effect of neutrophils on tumor immunity and immunotherapy resistance with underlying mechanisms

Neutrophils are key mediators of the immune response and play essential roles in the development of tumors and immune evasion. Emerging studies indicate that neutrophils also play a critical role in the immunotherapy resistance in cancer. In this review, firstly, we summarize the novel classification and phenotypes of neutrophils and describe the regulatory relationships between neutrophils and tumor metabolism, flora microecology, neuroendocrine and tumor therapy from a new perspective. Secondly, we review the mechanisms by which neutrophils affect drug resistance in tumor immunotherapy from the aspects of the immune microenvironment, tumor antigens, and epigenetics. Finally, we propose several promising strategies for overcoming tumor immunotherapy resistance by targeting neutrophils and provide new research ideas in this area.

Pinpointing the integration of artificial intelligence in liver cancer immune microenvironment

Liver cancer remains one of the most formidable challenges in modern medicine, characterized by its high incidence and mortality rate. Emerging evidence underscores the critical roles of the immune microenvironment in tumor initiation, development, prognosis, and therapeutic responsiveness. However, the composition of the immune microenvironment of liver cancer (LC-IME) and its association with clinicopathological significance remain unelucidated. In this review, we present the recent developments related to the use of artificial intelligence (AI) for studying the immune microenvironment of liver cancer, focusing on the deciphering of complex high-throughput data. Additionally, we discussed the current challenges of data harmonization and algorithm interpretability for studying LC-IME.

Copper chelation redirects neutrophil function to enhance anti-GD2 antibody therapy in neuroblastoma

Anti-disialoganglioside (GD2) antibody therapy has provided clinical benefit to patients with neuroblastoma however efficacy is likely impaired by the immunosuppressive tumor microenvironment. We have previously defined a link between intratumoral copper levels and immune evasion. Here, we report that adjuvant copper chelation potentiates anti-GD2 antibody therapy to confer durable tumor control in immunocompetent models of neuroblastoma. Mechanistic studies reveal copper chelation creates an immune-primed tumor microenvironment through enhanced infiltration and activity of Fc-receptor-bearing cells, specifically neutrophils which are emerging as key effectors of antibody therapy. Moreover, we report copper sequestration by neuroblastoma attenuates neutrophil function which can be successfully reversed using copper chelation to increase pro-inflammatory effector functions. Importantly, we repurpose the clinically approved copper chelating agent Cuprior as a non-toxic, efficacious immunomodulatory strategy. Collectively, our findings provide evidence for the clinical testing of Cuprior as an adjuvant to enhance the activity of anti-GD2 antibody therapy and improve outcomes for patients with neuroblastoma.

Neutrophil diversity and function in health and disease

Neutrophils, the most abundant type of granulocyte, are widely recognized as one of the pivotal contributors to the acute inflammatory response. Initially, neutrophils were considered the mobile infantry of the innate immune system, tasked with the immediate response to invading pathogens. However, recent studies have demonstrated that neutrophils are versatile cells, capable of regulating various biological processes and impacting both human health and disease. Cytokines and other active mediators regulate the functional activity of neutrophils by activating multiple receptors on these cells, thereby initiating downstream signal transduction pathways. Dysfunctions in neutrophils and disruptions in neutrophil homeostasis have been implicated in the pathogenesis of numerous diseases, including cancer and inflammatory disorders, often due to aberrant intracellular signaling. This review provides a comprehensive synthesis of neutrophil biological functions, integrating recent advancements in this field. Moreover, it examines the biological roles of receptors on neutrophils and downstream signaling pathways involved in the regulation of neutrophil activity. The pathophysiology of neutrophils in numerous human diseases and emerging therapeutic approaches targeting them are also elaborated. This review also addresses the current limitations within the field of neutrophil research, highlighting critical gaps in knowledge that warrant further investigation. In summary, this review seeks to establish a comprehensive and multidimensional model of neutrophil regulation, providing new perspectives for potential clinical applications and further research.

Investigating intra-tumoural heterogeneity and microenvironment diversity in primary cardiac angiosarcoma through single-cell RNA sequencing

BACKGROUND

Primary cardiac angiosarcoma (PCAS) is a rare and aggressive heart tumour with limited treatment options and a poor prognosis. Understanding cellular heterogeneity and tumour microenvironment (TME) is crucial for the development of effective therapies. Here, we investigated the intratumoural heterogeneity and TME diversity of PCAS using single-cell RNA sequencing (scRNA-seq).

METHODS

We performed scRNA-seq analysis on tumour samples from four patients with PCAS, supplemented with multicolour immunohistochemistry for identification. We used scRNA-seq data from five normal cardiac tissue samples downloaded from public databases for comparative analyses. Bioinformatic analyses, including Cell Ranger, Seurat, Monocle2, hdWGCNA, SCENIC and NicheNet, were utilized to identify distinct cell populations, transcriptional patterns, and co-regulating gene modules.

RESULTS

Our analysis revealed significant intratumoural heterogeneity in PCAS driven by diverse biological processes such as protein synthesis, degradation, and RIG-I signalling inhibition. The SCENIC analysis identified three primary transcription factors' clusters (CEBPB, MYC and TAL1). T-cell subset analysis showed exhausted antigen-specific T-cells, complicating the efficacy of immune checkpoint blockade. Furthermore, we observed suppressive macrophages (SPP1+ and OLR1+) and reduced mitochondrial gene MT-RNR2 (MTRNR2L12) expression in TME-infiltrating cells, indicating impaired mitochondrial function.

CONCLUSION

This study elucidates the complex cellular landscape and immune microenvironment of PCAS, highlighting potential molecular targets for the development of novel therapies. These findings underscore the importance of a multifaceted therapeutic approach for addressing the challenges posed by PCAS's heterogeneity and immune evasion.

KEY POINTS

Insights into the heterogeneity and transcriptional patterns of sarcoma cells may explain the challenges in treating primary cardiac angiosarcoma (PCAS) using the current therapeutic modalities. Characterization of the immune microenvironment revealed significant immunosuppression mediated by specific myeloid cell populations (SPP1+ and OLR1+ macrophages). Identification of mitochondrial dysfunction in immune cells within the PCAS microenvironment, particularly the notable downregulation of the MTRNR2L12 protein, suggests a new avenue for therapeutic targeting.

Progress in Lactate Metabolism and Its Regulation via Small Molecule Drugs

Lactate, once viewed as a byproduct of glycolysis and a metabolic "waste", is now recognized as an energy-providing substrate and a signaling molecule that modulates cellular functions under pathological conditions. The discovery of histone lactylation in 2019 marked a paradigm shift, with subsequent studies revealing that lactate can undergo lactylation with both histone and non-histone proteins, implicating it in the pathogenesis of various diseases, including cancer, liver fibrosis, sepsis, ischemic stroke, and acute kidney injury. Aberrant lactate metabolism is associated with disease onset, and its levels can predict disease outcomes. Targeting lactate production, transport, and lactylation may offer therapeutic potential for multiple diseases, yet a systematic summary of the small molecules modulating lactate and its metabolism in various diseases is lacking. This review outlines the sources and clearance of lactate, as well as its roles in cancer, liver fibrosis, sepsis, ischemic stroke, myocardial infarction, and acute kidney injury, and summarizes the effects of small molecules on lactate regulation. It aims to provide a reference and direction for future research.

Neutrophils in nasal polyps exhibit transcriptional adaptation and proinflammatory roles that depend on local polyp milieu

Chronic rhinosinusitis with nasal polyps (CRSwNP) is an inflammatory upper airway disease, divided into eosinophilic CRSwNP (eCRSwNP) and noneosinophilic CRSwNP (neCRSwNP) according to eosinophilic levels. Neutrophils are major effector cells in CRSwNP, but their roles in different inflammatory environments remain largely unclear. We performed an integrated transcriptome analysis of polyp-infiltrating neutrophils from patients with CRSwNP, using healthy donor blood as a control. Additional experiments, including flow cytometry and in vitro epithelial cell and fibroblast culture, were performed to evaluate the phenotypic feature and functional role of neutrophils in CRSwNP. Single-cell RNA-sequencing analysis demonstrated that neutrophils could be classified into 5 functional subsets, with GBP5+ neutrophils occurring mainly in neCRSwNP and a high proportion of CXCL8+ neutrophils in both subendotypes. GBP5+ neutrophils exhibited significant IFN-I pathway activity in neCRSwNP. CXCL8+ neutrophils displayed increased neutrophil activation scores and mainly secreted oncostatin M (OSM), which facilitates communication with other cells. In vitro experiments showed that OSM enhanced IL-13- or IL-17-mediated immune responses in nasal epithelial cells and fibroblasts. Our findings indicate that neutrophils display transcriptional plasticity and activation when exposed to polyp tissue, contributing to CRSwNP pathogenesis by releasing OSM, which interacts with epithelial cells and fibroblasts depending on the inflammatory environment.

BHLHE40-mediated transcriptional activation of GRIN2D in gastric cancer is involved in metabolic reprogramming

Gastric cancer (GC) is the third leading cause of death in developed countries. The reprogramming of energy metabolism represents a hallmark of cancer, particularly amplified dependence on aerobic glycolysis. Here, we aimed to illustrate the functional role of glutamate ionotropic receptor N-methyl-D-aspartate type subunit 2D (GRIN2D) in the regulation of glycolysis in GC and the mechanisms involved. Differentially expressed genes were analyzed using the GEO and GEPIA databases, followed by prognostic value prediction using the Kaplan-Meier Plotter database. The effect of GRIN2D knockdown on the malignant behavior and glycolysis of GC cells was explored. GRIN2D expression was upregulated in GC cells and promoted the malignant behavior of GC cells by activating glycolysis. Class E basic helix-loop-helix protein 40 (BHLHE40) was overexpressed in GC cells and mediated transcriptional activation of GRIN2D. The anti-tumor effects of BHLHE40 knockdown on GC cells in vitro and in vivo were reversed by GRIN2D overexpression. Knockdown of GRIN2D or BHLHE40 downregulated the expression of mRNA of electron transport chain subunits and phosphorylation of p38 MARK and inhibited calcium efflux in GC cells. Overexpression of GRIN2D promoted calcium efflux, phosphorylation of p38 MARK protein, and proliferation of GES1 cells. Altogether, the findings derived from this study suggest that BHLHE40 knockdown suppresses the growth, mobility, and glycolysis of GC cells by inhibiting GRIN2D transcription and disrupting the BHLHE40/GRIN2D axis may be an attractive therapeutic strategy for GC.

Targeting SPP1-orchestrated neutrophil extracellular traps-dominant pre-metastatic niche reduced HCC lung metastasis

Background

The mechanisms by which tumor-derived factors remodel the microenvironment of target organs to facilitate cancer metastasis, especially organ-specific metastasis, remains obscure. Our previous studies have demonstrated that SPP1 plays a key role in promoting metastasis of hepatocellular carcinoma (HCC). However, the functional roles and mechanisms of tumor-derived SPP1 in shaping the pre-metastatic niche (PMN) and promoting lung-specific metastasis are unclear.

Methods

Orthotopic metastasis models, experimental metastasis models, CyTOF and flow cytometry were conducted to explore the function of SPP1 in shaping neutrophil-dominant PMN and promoting HCC lung metastasis. The main source of CXCL1 in lung tissues was investigated via fluorescence activated cell sorting and immunofluorescence staining. The expression of neutrophils and neutrophil extracellular traps (NETs) markers was detected in the lung metastatic lesions of HCC patients and mouse lung specimens. The therapeutic significance was explored via in vivo DNase I and CXCR2 inhibitor assays.

Results

SPP1 promoted HCC lung colonization and metastasis by modifying pulmonary PMN in various murine models, and plasma SPP1 levels were closely associated with lung metastasis in HCC patients. Mechanistically, SPP1 binded to CD44 on lung alveolar epithelial cells to produce CXCL1, thereby attracting and forming neutrophil-abundant PMN in the lung. The recruited neutrophils were activated by SPP1 and then formed NETs-dominant PMN to trap the disseminated tumor cells and promote metastatic colonization. Moreover, early intervention of SPP1-orchestrated PMN by co-targeting the CXCL1-CXCR2 axis and NETs formation could efficiently inhibit the lung metastasis of HCC.

Conclusions

Our study illustrates that HCC-lung host cell-neutrophil interactions play important roles in PMN formation and SPP1-induced HCC lung metastasis. Early intervention in SPP1-orchestrated PMN via CXCR2 inhibitor and DNase I is a potential therapeutic strategy to combat HCC lung metastasis.

Targeting SPP1-orchestrated neutrophil extracellular traps-dominant pre-metastatic niche reduced HCC lung metastasis

BACKGROUND

The mechanisms by which tumor-derived factors remodel the microenvironment of target organs to facilitate cancer metastasis, especially organ-specific metastasis, remains obscure. Our previous studies have demonstrated that SPP1 plays a key role in promoting metastasis of hepatocellular carcinoma (HCC). However, the functional roles and mechanisms of tumor-derived SPP1 in shaping the pre-metastatic niche (PMN) and promoting lung-specific metastasis are unclear.

METHODS

Orthotopic metastasis models, experimental metastasis models, CyTOF and flow cytometry were conducted to explore the function of SPP1 in shaping neutrophil-dominant PMN and promoting HCC lung metastasis. The main source of CXCL1 in lung tissues was investigated via fluorescence activated cell sorting and immunofluorescence staining. The expression of neutrophils and neutrophil extracellular traps (NETs) markers was detected in the lung metastatic lesions of HCC patients and mouse lung specimens. The therapeutic significance was explored via in vivo DNase I and CXCR2 inhibitor assays.

RESULTS

SPP1 promoted HCC lung colonization and metastasis by modifying pulmonary PMN in various murine models, and plasma SPP1 levels were closely associated with lung metastasis in HCC patients. Mechanistically, SPP1 binded to CD44 on lung alveolar epithelial cells to produce CXCL1, thereby attracting and forming neutrophil-abundant PMN in the lung. The recruited neutrophils were activated by SPP1 and then formed NETs-dominant PMN to trap the disseminated tumor cells and promote metastatic colonization. Moreover, early intervention of SPP1-orchestrated PMN by co-targeting the CXCL1-CXCR2 axis and NETs formation could efficiently inhibit the lung metastasis of HCC.

CONCLUSIONS

Our study illustrates that HCC-lung host cell-neutrophil interactions play important roles in PMN formation and SPP1-induced HCC lung metastasis. Early intervention in SPP1-orchestrated PMN via CXCR2 inhibitor and DNase I is a potential therapeutic strategy to combat HCC lung metastasis.

Multifaceted roles of neutrophils in tumor microenvironment

Neutrophils, the most abundant leukocyte population in circulation, play a crucial role in detecting and responding to foreign cells, such as pathogens and tumor cells. However, the impact of neutrophils on cancer pathogenesis has been overlooked because of their short lifespan, terminal differentiation, and limited transcriptional activity. Within the tumor microenvironment (TME), neutrophils can be influenced by tumor cells or other stromal cells to acquire either protumor or antitumor properties via the cytokine environment. Despite progress in neutrophil-related research, a comprehensive understanding of tissue-specific neutrophil diversity and adaptability in the TME is still lacking, which poses a significant obstacle to the development of neutrophil-based cancer therapies. This review evaluated the current studies on the dual roles of neutrophils in cancer progression, emphasizing their importance in predicting clinical outcomes, and explored various approaches for targeting neutrophils in cancer treatment, including their potential synergy with cancer immunotherapy.

Comprehensive multi-omics profiling identifies novel molecular subtypes of pancreatic ductal adenocarcinoma

Pancreatic cancer, a highly fatal malignancy, is predicted to rank as the second leading cause of cancer-related death in the next decade. This highlights the urgent need for new insights into personalized diagnosis and treatment. Although molecular subtypes of pancreatic cancer were well established in genomics and transcriptomics, few known molecular classifications are translated to guide clinical strategies and require a paradigm shift. Notably, chronically developing and continuously improving high-throughput technologies and systems serve as an important driving force to further portray the molecular landscape of pancreatic cancer in terms of epigenomics, proteomics, metabonomics, and metagenomics. Therefore, a more comprehensive understanding of molecular classifications at multiple levels using an integrated multi-omics approach holds great promise to exploit more potential therapeutic options. In this review, we recapitulated the molecular spectrum from different omics levels, discussed various subtypes on multi-omics means to move one step forward towards bench-to-beside translation of pancreatic cancer with clinical impact, and proposed some methodological and scientific challenges in store.

Neutrophils as promising therapeutic targets in pancreatic cancer liver metastasis

Pancreatic cancer is characterized by an extremely poor prognosis and presents significant treatment challenges. Liver metastasis is the leading cause of death in patients with pancreatic cancer. Recent studies have highlighted the significant impact of neutrophils on tumor occurrence and progression, as well as their crucial role in the pancreatic cancer tumor microenvironment. Neutrophil infiltration plays a critical role in the progression and prognosis of pancreatic cancer. Neutrophils contribute to pancreatic cancer liver metastasis through various mechanisms, including angiogenesis, immune suppression, immune evasion, and epithelial-mesenchymal transition (EMT). Therefore, targeting neutrophils holds promise as an important therapeutic strategy for inhibiting pancreatic cancer liver metastasis. This article provides a summary of research findings on the involvement of neutrophils in pancreatic cancer liver metastasis and analyzes their potential as therapeutic targets. This research may provide new insights for the treatment of pancreatic cancer and improve the prognosis of patients with this disease.

Single-cell RNA sequencing and spatial transcriptome reveal potential molecular mechanisms of lung cancer brain metastasis

BACKGROUND

Lung cancer is a highly aggressive and prevalent disease worldwide. By the time it is first diagnosed, distant metastases have usually already occurred. Among them, the prognosis of patients with brain metastasis from lung cancer is very poor. Therefore, it is particularly important to identify the evolutionary status of tumor cells during lung cancer brain metastases and discover the underlying mechanisms of lung cancer brain metastases.

METHODS

In this study, we analysed three types of data: single-cell RNA sequencing, bulk RNA sequencing, and spatial transcriptome. Firstly, we identified early metastatic epithelial cell clusters (EMEC) using CNV and trajectory analysis in scRNA-seq data. Secondly, we integrated scRNA-seq and spatial transcriptome data with the help of MIA (Multimodal intersection analysis) to explore the biological characteristics of EMEC. Finally, we used bulk RNA-seq data to validate the molecular characteristics of EMEC.

RESULT

A total of 55,763 single cells were obtained and divided into 9 cell types. In brain metastasis, we found a significantly higher proportion of epithelial cells. In addition, we identified a specific subpopulation of epithelial cells, which was named as "early metastatic epithelial cell clusters (EMEC)". It is enriched in oxidative phosphorylation, coagulation, complement. Moreover, we also found that EMEC underwent cellular communication with other immune cells through ligand-receptor pairs such as MIF-(CD74 + CXCR4) and MIF-(CD74 + CD44). Next, we validated that EMEC were associated with poor clinical prognosis using three independent external datasets. Finally, spatial transcriptome analysis revealed specificity in the spatial distribution of EMEC, which shifted from the peripheral regions to the central regions of the tumour as the depth of tumor invasion progressed.

CONCLUSION

This study reveals the potential molecular mechanisms of lung cancer brain metastasis from both single-cell and spatial transcriptomic perspectives, providing biological insights and clinical reference value for detecting patients suffering from lung cancer brain metastasis.

Knowledge landscape of tumor-associated neutrophil: a bibliometric and visual analysis from 2000-2024

Background

Neutrophils have long been consistently adjudged to hold a dominant position in acute inflammation, which once led people to undervalue their role in chronic malignancy. It is now acknowledged that neutrophils also infiltrate into the tumor microenvironment in substantial quantities and form a highly abundant immune population within the tumor, known as tumor-associated neutrophils (TANs). There has been a surge of interest in researching the eminent heterogeneity and plasticity of TANs in recent years, and scholars increasingly cotton on to the multifaceted functions of TANs so that strenuous endeavors have been devoted to enunciating their potential as therapeutic targets. Yet it remains much left to translate TAN-targeted immunotherapies into clinical practice. Therefore, there is great significance to comprehensively appraise the research status, focal point, and evolution trend of TAN by using bibliometric analysis.

Methods

Publications related to TAN research from 2000 to 2024 are extracted from the Web of Science Core Collection. Bibliometric analysis and visualization were performed by tools encompassing Microsoft Excel, VOSviewer, CiteSpace, R-bibliometrix, and so on.

Results

The bibliometric analysis included a total of 788 publications authored by 5291 scholars affiliated with 1000 institutions across 58 countries/regions, with relevant articles published in 324 journals. Despite China's maximum quantity of publications and top 10 institutions, the United States is the leading country with the most high-quality publications and is also the global cooperation center. FRONTIERS IN IMMUNOLOGY published the most papers, whereas CANCER RESEARCH is the highest co-cited journal. Israeli professor Fridlender, Zvi G. is the founder, pioneer, and cultivator with the highest citation counts and H-index in the TAN area. Our analysis prefigures the future trajectories: TAN heterogeneity, neutrophil extracellular trap, the crosstalk between TANs and immunocytes, and immunotherapy will likely be the focus of future research.

Conclusion

A comprehensive bibliometric and visual analysis is first performed to map the current landscape and intellectual structure of TAN, which proffers fresh perspectives for further research. The accurate identification of distinct TAN subpopulations and the precise targeting of key pro-tumor/anti-tumor subpopulations hold immense potential to develop into a TAN-targeted immunotherapy.

Engineered extracellular vesicles enable high-efficient delivery of intracellular therapeutic proteins

Developing an intracellular delivery system is of key importance in the expansion of protein-based therapeutics acting on cytosolic or nuclear targets. Recently, extracellular vesicles (EVs) have been exploited as next-generation delivery modalities due to their natural role in intercellular communication and biocompatibility. However, fusion of protein of interest to a scaffold represents a widely used strategy for cargo enrichment in EVs, which could compromise the stability and functionality of cargo. Herein, we report intracellular delivery via EV-based approach (IDEA) that efficiently packages and delivers native proteins both in vitro and in vivo without the use of a scaffold. As a proof-of-concept, we applied the IDEA to deliver cyclic GMP-AMP synthase (cGAS), an innate immune sensor. The results showed that cGAS-carrying EVs activated interferon signaling and elicited enhanced antitumor immunity in multiple syngeneic tumor models. Combining cGAS EVs with immune checkpoint inhibition further synergistically boosted antitumor efficacy in vivo. Mechanistically, scRNA-seq demonstrated that cGAS EVs mediated significant remodeling of intratumoral microenvironment, revealing a pivotal role of infiltrating neutrophils in the antitumor immune milieu. Collectively, IDEA, as a universal and facile strategy, can be applied to expand and advance the development of protein-based therapeutics.

ALDH1A3 is the switch that determines the balance of ALDH+ and CD24-CD44+ cancer stem cells, EMT-MET, and glucose metabolism in breast cancer

Plasticity is an inherent feature of cancer stem cells (CSCs) and regulates the balance of key processes required at different stages of breast cancer progression, including epithelial-to-mesenchymal transition (EMT) versus mesenchymal-to-epithelial transition (MET), and glycolysis versus oxidative phosphorylation. Understanding the key factors that regulate the switch between these processes could lead to novel therapeutic strategies that limit tumor progression. We found that aldehyde dehydrogenase 1A3 (ALDH1A3) regulates these cancer-promoting processes and the abundance of the two distinct breast CSC populations defined by high ALDH activity and CD24-CD44+ cell surface expression. While ALDH1A3 increases ALDH+ breast cancer cells, it inversely suppresses the CD24-CD44+ population by retinoic acid signaling-mediated gene expression changes. This switch in CSC populations induced by ALDH1A3 was paired with decreased migration but increased invasion and an intermediate EMT phenotype. We also demonstrate that ALDH1A3 increases oxidative phosphorylation and decreases glycolysis and reactive oxygen species (ROS). The effects of ALDH1A3 reduction were countered with the glycolysis inhibitor 2-deoxy-D-glucose (2DG). In cell culture and tumor xenograft models, 2DG suppresses the increase in the CD24-CD44+ population and ROS induced by ALDH1A3 knockdown. Combined inhibition of ALDH1A3 and glycolysis best reduces breast tumor growth and tumor-initiating cells, suggesting that the combination of targeting ALDH1A3 and glycolysis has therapeutic potential for limiting CSCs and tumor progression. Together, these findings identify ALDH1A3 as a key regulator of processes required for breast cancer progression and depletion of ALDH1A3 makes breast cancer cells more susceptible to glycolysis inhibition.

Deciphering breast cancer dynamics: insights from single-cell and spatial profiling in the multi-omics era

As one of the most common tumors in women, the pathogenesis and tumor heterogeneity of breast cancer have long been the focal point of research, with the emergence of tumor metastasis and drug resistance posing persistent clinical challenges. The emergence of single-cell sequencing (SCS) technology has introduced novel approaches for gaining comprehensive insights into the biological behavior of malignant tumors. SCS is a high-throughput technology that has rapidly developed in the past decade, providing high-throughput molecular insights at the individual cell level. Furthermore, the advent of multitemporal point sampling and spatial omics also greatly enhances our understanding of cellular dynamics at both temporal and spatial levels. The paper provides a comprehensive overview of the historical development of SCS, and highlights the most recent advancements in utilizing SCS and spatial omics for breast cancer research. The findings from these studies will serve as valuable references for future advancements in basic research, clinical diagnosis, and treatment of breast cancer.

Exosomal miR-4745-5p/3911 from N2-polarized tumor-associated neutrophils promotes gastric cancer metastasis by regulating SLIT2

Tumor cells remodel the phenotype and function of tumor microenvironment (TME) cells to favor tumor progression. Previous studies have shown that neutrophils in TME are polarized to N2 tumor-associated neutrophils (TANs) by tumor derived factors, thus promoting tumor growth and metastasis, angiogenesis, therapy resistance, and immunosuppression. Exosomes act as critical intercellular messengers in human health and diseases including cancer. So far, the biological roles of exosomes from N2 TANs in gastric cancer have not been well characterized. Herein, we represented the first report that exosomes from N2 TANs promoted gastric cancer metastasis in vitro and in vivo. We found that exosomes from N2 TANs transferred miR-4745-5p/3911 to gastric cancer cells to downregulate SLIT2 (slit guidance ligand 2) gene expression. Adenovirus-mediated overexpression of SLIT2 reversed the promotion of gastric cancer metastasis by N2 TANs derived exosomes. We further revealed that gastric cancer cells induced glucose metabolic reprogramming in neutrophils through exosomal HMGB1 (high mobility group protein B1)/NF-κB pathway, which mediated neutrophil N2 polarization and miR-4745-5p/3911 upregulation. We further employed ddPCR (droplet digital PCR) to detect the expression of miR-4745-5p/3911 in N2 TANs exosomes from human serum samples and found their increased levels in gastric cancer patients compared to healthy controls and benign gastric disease patients. Conclusively, our results indicate that N2 TANs facilitate cancer metastasis via regulation of SLIT2 in gastric cancer cells by exosomal miR-4745-5p/3911, which provides a new insight into the roles of TME cells derived exosomes in gastric cancer metastasis and offers a potential biomarker for gastric cancer diagnosis.

Barriers and opportunities in pancreatic cancer immunotherapy

Pancreatic ductal adenocarcinoma (PDAC) presents a fatal clinical challenge characterized by a dismal 5-year overall survival rate, primarily due to the lack of early diagnosis and limited therapeutic efficacy. Immunotherapy, a proven success in multiple cancers, has yet to demonstrate significant benefits in PDAC. Recent studies have revealed the immunosuppressive characteristics of the PDAC tumor microenvironment (TME), including immune cells with suppressive properties, desmoplastic stroma, microbiome influences, and PDAC-specific signaling pathways. In this article, we review recent advances in understanding the immunosuppressive TME of PDAC, TME differences among various mouse models of pancreatic cancer, and the mechanisms underlying resistance to immunotherapeutic interventions. Furthermore, we discuss the potential of targeting cancer cell-intrinsic pathways and TME components to sensitize PDAC to immune therapies, providing insights into strategies and future perspectives to break through the barriers in improving pancreatic cancer treatment.

Tumor-associated neutrophils upregulate Nectin2 expression, creating the immunosuppressive microenvironment in pancreatic ductal adenocarcinoma

BACKGROUND

Tumor-associated neutrophils (TANs) constitute an abundant component among tumor-infiltrating immune cells and have recently emerged as a critical player in pancreatic ductal adenocarcinoma (PDAC) progression. This study aimed to elucidate the pro-tumor mechanisms of TAN and identify a novel target for effective immunotherapy against PDAC.

METHODS

Microarray and cytokine array analyses were performed to identify the mechanisms underlying the function of TANs. Human and mouse TANs were obtained from differentiated HL-60 cells and orthotopically transplanted PDAC tumors, respectively. The interactions of TANs with cancer and cytotoxic T-cells were evaluated through in vitro co-culture and in vivo orthotopic or subcutaneous models. Single-cell transcriptomes from patients with PDAC were analyzed to validate the cellular findings.

RESULTS

Increased neutrophil infiltration in the tumor microenvironment was associated with poor survival in patients with PDAC. TANs secreted abundant amounts of chemokine ligand 5 (CCL5), subsequently enhancing cancer cell migration and invasion. TANs subpopulations negatively correlated with cytotoxic CD8+ T-cell infiltration in PDAC and promoted T-cell dysfunction. TANs upregulated the membranous expression of Nectin2, which contributed to CD8+ T-cell exhaustion. Blocking Nectin2 improved CD8+ T-cell function and suppressed tumor progression in the mouse model. Single-cell analysis of human PDAC revealed two immunosuppressive TANs phenotypes: Nectin2+ TANs and OLR1+ TANs. Endoplasmic reticulum stress regulated the protumor activities in TANs.

CONCLUSIONS

TANs enhance PDAC progression by secreting CCL5 and upregulating Nectin2. Targeting the immune checkpoint Nectin2 could represent a novel strategy to enhance immunotherapy efficacy in PDAC.

CD71 expressing circulating neutrophils serve as a novel prognostic biomarker for metastatic spread and reduced outcome in pancreatic ductal adenocarcinoma patients

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies, presenting a persisting global health burden. Neutrophils have a double-edged role in tumor progression exhibiting both pro-tumor and anti-tumor functions. CD71, also known as transferrin receptor 1, performs a critical role in cellular iron uptake and is highly expressed on proliferating cells, and especially on activated immune cells. CD71 is known to be elevated in various types of solid cancers and is associated with poor prognosis, however, the expression of CD71 on neutrophils in PDAC and its potential clinical impact is still unknown. Therefore, we analyzed CD71 on circulating neutrophils in PDAC and clinical control patients and found a significant increased expression in PDAC patients. High expression of CD71 on neutrophils in PDAC patients was associated with reduced outcome compared to low expression. CD71 on neutrophils correlated positively with the levels of proinflammatory cytokines IL-6, IFN-γ, and growth factor ligands CD40-L, and BAFF in plasma of PDAC patients. Finally, we have demonstrated that high expression of CD71 on neutrophils was also associated with an increased expression of CD39 and CD25 on circulating T-cells. Based on our findings, we hypothesize that CD71 on neutrophils is associated with tumor progression in PDAC. Further studies are required to investigate the distinct functionality of CD71 expressing neutrophils and their potential clinical application.

A distribution-free and analytic method for power and sample size calculation in single-cell differential expression

MOTIVATION

Differential expression analysis in single-cell transcriptomics unveils cell type-specific responses to various treatments or biological conditions. To ensure the robustness and reliability of the analysis, it is essential to have a solid experimental design with ample statistical power and sample size. However, existing methods for power and sample size calculation often assume a specific distribution for single-cell transcriptomics data, potentially deviating from the true data distribution. Moreover, they commonly overlook cell-cell correlations within individual samples, posing challenges in accurately representing biological phenomena. Additionally, due to the complexity of deriving an analytic formula, most methods employ time-consuming simulation-based strategies.

RESULTS

We propose an analytic-based method named scPS for calculating power and sample sizes based on generalized estimating equations. scPS stands out by making no assumptions about the data distribution and considering cell-cell correlations within individual samples. scPS is a rapid and powerful approach for designing experiments in single-cell differential expression analysis.

AVAILABILITY AND IMPLEMENTATION

scPS is freely available at https://github.com/cyhsuTN/scPS and Zenodo https://zenodo.org/records/13375996.