Myeloid-derived cells (MDCs) are crucial in immune response and tissue homeostasis. They have high functional plasticity and can be polarized according to microenvironment signals. These cells, including macrophages, neutrophils, and dendritic cells (DCs), exhibit different functional polarization states in different pathological environments and are involved in the occurrence and development of diseases such as inflammation and tumors. Studies have shown that metabolic reprogramming plays a key role in the functional polarization of MDCs, affecting the cellular energy supply and regulating immune function. This paper reviews classification, function and polarization mechanism of MDCs and discusses metabolic reprogramming. In addition, the therapeutic strategies targeting MDC are summarized, which is expected to provide new targets for tumor immunotherapy.
Humans ; Tumor Microenvironment/immunology* ; Myeloid Cells/metabolism* ; Neoplasms/pathology* ; Animals ; Immunotherapy/methods* ; Dendritic Cells/immunology* ; Macrophages/immunology*

T cell exhaustion plays an immunosuppressive role in malignant tumors. Continuous tumor antigen stimulation, the presence of suppressive immune cells and cytokines in the tumor microenvironment, the up regulation of inhibitory receptor expression on the surface of T cells, changes in T cell related transcription factors, and metabolites in the tumor microenvironment may lead to T cell exhaustion. Reversing the exhaustion of T cells in tumor patients is a promising strategy for tumor immunotherapy. This article will review the latest research progress on T cell exhaustion status, pathogenesis, reversal methods, and clinical applications in hematological tumors.
Humans ; Hematologic Neoplasms/immunology* ; T-Lymphocytes/immunology* ; Tumor Microenvironment ; Immunotherapy ; T-Cell Exhaustion

Lung cancer is one of the most common and lethal malignancies in China. In the context of the tumor microenvironment, neutrophil extracellular traps (NETs) released by neutrophils exert a profound impact on the occurrence and progression of lung cancer. Although the exact mechanisms by which NETs promote tumor growth have not been fully elucidated, existing research has revealed their multiple roles in tumor growth, invasion, metastasis, and cancer-related thrombosis. This article will review the molecular biology mechanisms and research progress of NETs in lung cancer based on recent studies.
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Extracellular Traps/metabolism* ; Humans ; Lung Neoplasms/drug therapy* ; Neutrophils/immunology* ; Animals ; Tumor Microenvironment

Neutrophil extracellular traps (NETs), intricate reticular structures released by activated neutrophils, play a pivotal regulatory role in the pathogenesis of malignant tumors. Lung cancer is one of the most prevalent malignancies globally, with persistently high incidence and mortality rates. Recent studies have revealed that NETs dynamically modulate the tumor microenvironment through unique pathological mechanisms, exhibiting complex immunoregulatory characteristics during the progression of lung cancer, and this discovery has increasingly become a focal point in tumor immunology research. This paper provides a comprehensive review of the latest advancements in NETs research related to lung cancer, offering an in-depth analysis of their impact on lung cancer progression, their potential diagnostic value, and the current state of research on targeting NETs for lung cancer prevention and treatment. The aim is to propose novel strategies to enhance therapeutic outcomes and improve the prognosis for lung cancer patients.
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Extracellular Traps/immunology* ; Humans ; Lung Neoplasms/metabolism* ; Neutrophils/metabolism* ; Animals ; Tumor Microenvironment

Despite the groundbreaking advances in cancer immunotherapy achieved by immune checkpoint inhibitors (ICIs), their efficacy remains limited by the immunosuppressive tumor microenvironment (TME). Yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ), key effectors of the Hippo signaling pathway, play pivotal roles in tumor immune evasion. They directly regulate the expression of immune checkpoints, mediate the formation of an immunosuppressive microenvironment, inhibit T cell function, and interact with other signaling pathways to promote immune escape. Diverse strategies targeting YAP/TAZ have been developed, including direct inhibition, modulation of upstream regulators, and suppression of downstream target genes. Preclinical studies have demonstrated that combining YAP/TAZ inhibition with ICIs significantly enhances therapeutic efficacy across various tumor models. This review summarizes recent advances in understanding the role of YAP/TAZ in immune evasion within the TME and explores the potential of targeting this pathway to improve immunotherapy outcomes. Furthermore, it discusses the translational value of combination therapies based on YAP/TAZ inhibition, providing a theoretical framework and practical guidance for the development of innovative immunotherapeutic strategies and precision medicine approaches.
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Humans ; Immunotherapy/methods* ; Neoplasms/metabolism* ; Signal Transduction/drug effects* ; Adaptor Proteins, Signal Transducing/immunology* ; Animals ; Transcriptional Coactivator with PDZ-Binding Motif Proteins ; Transcription Factors/immunology* ; YAP-Signaling Proteins ; Tumor Microenvironment

Lung cancer remains one of the most prevalent and deadly malignancies worldwide, with persistently low five-year survival rates. This poor prognosis is primarily attributed to challenges such as difficulties in early diagnosis, high tumor heterogeneity, and strong therapeutic resistance. Although recent advances in targeted therapies and immune checkpoint inhibitors have significantly improved the prognosis of some patients, the majority still encounter primary or secondary resistance. Galectin-3, a multifunctional glycan-binding protein, is constitutively expressed in pulmonary tissues. Its expression encompasses bronchial and alveolar epithelial cells, the pulmonary vasculature, and resident immune cells. Galectin-3 plays a central role in lung cancer progression by regulating tumor cell proliferation, immune evasion, and angiogenesis. The complex immunosuppressive mechanisms within the tumor microenvironment not only facilitate tumor growth and metastasis but also partially limit the efficacy of cancer immunotherapies. Overcoming these barriers requires the exploration of novel regulatory targets to break through therapeutic bottlenecks. This review systematically elucidates the mechanisms by which galectin-3 interacts with immune cells (e.g., T cells, macrophages) in the tumor microenvironment and evaluates its potential as a therapeutic target, including inhibitor development and combination immunotherapy strategies. The findings aim to provide a theoretical foundation for advancing galectin-3 as a novel therapeutic target in lung cancer and offer new perspectives for overcoming current immunotherapy resistance.
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Humans ; Lung Neoplasms/pathology* ; Tumor Microenvironment/immunology* ; Galectin 3/genetics* ; Animals ; Immunomodulation ; Immunotherapy

BACKGROUND: Lung adenocarcinoma (LUAD) remains one of the leading causes of cancer morbidity and mortality worldwide, and its initiation and progression are closely associated with the tumor immune microenvironment. Increasing evidence suggests that environmental exposure is a critical factor influencing lung cancer development. Among these factors, fine particulate matter (PM2.5), a major component of air pollution, has been strongly linked to elevated lung cancer risk and unfavorable prognosis. However, the underlying immunoregulatory mechanisms by which PM2.5 drives LUAD progression remain poorly understood. Tumor-associated macrophages (TAMs), especially those polarized toward the M2 phenotype, are key components of the tumor microenvironment and play crucial roles in tumor growth, angiogenesis, and immune evasion. This study aims to investigate the effects of PM2.5 exposure on TAMs and to identify the key pro-tumorigenic factors mediating this process. METHODS: A mouse orthotopic lung cancer model under PM2.5 exposure was established to assess lung tumor growth and macrophage phenotypic alterations using in vivo imaging and flow cytometry. A subcutaneous tumor model involving co-inoculated macrophages and tumor cells was used to further verify the effects of PM2.5 on the function of TAMs and tumor malignancy. Combining in vitro experiments, flow cytometry, Western blot, reverse transcription quantitative polymerase chain reaction (RT-qPCR), cell counting kit-8 (CCK-8) assay, colony formation assay, and wound healing assay were employed to evaluate the regulatory effects of PM2.5 on the polarization of bone marrow-derived macrophages (BMDMs) as well as tumor cell proliferation, migration, and colony-forming ability. Transcriptome sequencing integrated with TISIDB (Tumor-immune System Interactions Database) and GEPIA (Gene Expression Profiling Interactive Analysis) databases was performed to identify key cytokines for further functional validation. RESULTS: In the mouse orthotopic lung cancer model, PM2.5 exposure significantly promoted tumor growth and increased the proportion of M2-type TAMs (P<0.05). Subcutaneous co-inoculation with PM2.5-treated BMDMs markedly enhanced tumor proliferation and elevated the intratumoral M2-type TAMs. PM2.5-pretreated BMDMs exhibited an immunosuppressive programmed cell death ligand 1 (PD-L1)+/arginase 1 (Arg1)+ phenotype, and their conditioned media significantly promoted proliferation, migration, and colony formation of Lewis lung carcinoma cells (LLC) and B16 melanoma cells (B16) (P<0.05). Transcriptome analysis revealed that PM2.5 substantially altered macrophage gene expression, with IL-1α identified as a key upregulated secreted cytokine enriched in immunosuppressive related signaling pathways. Clinical database analyses further indicated that IL-1α expression was positively correlated with macrophage and regulatory T cells (Treg) infiltration in the LUAD immune microenvironment, and that high IL-1α expression was associated with worse overall survival in LUAD patients (HR=1.5, P=0.0053). Western blot, RT-qPCR, and immunofluorescence confirmed that PM2.5 exposure significantly upregulated IL-1α expression and secretion in TAMs. CONCLUSIONS PM2.5 exposure facilitates LUAD progression by inducing an immunosuppressive phenotype in macrophages and enhancing the malignant behaviors of tumor cells. Mechanistically, IL-1α may serve as a key pro-tumorigenic cytokine secreted by macrophages under PM2.5 exposure. This study provides new insights into the pathogenesis of PM2.5-associated LUAD and suggests that IL-1α could serve as a potential therapeutic target.
Animals ; Mice ; Tumor-Associated Macrophages/immunology* ; Particulate Matter/toxicity* ; Adenocarcinoma of Lung/metabolism* ; Lung Neoplasms/genetics* ; Humans ; Disease Progression ; Tumor Microenvironment/drug effects* ; Cell Proliferation/drug effects* ; Cell Line, Tumor

Recent data suggest that vascular endothelial growth factor receptor inhibitor (VEGFRi) can enhance the anti-tumor activity of the anti-programmed cell death-1 (anti-PD-1) antibody in colorectal cancer (CRC) with microsatellite stability (MSS). However, the comparison between this combination and standard third-line VEGFRi treatment is not performed, and reliable biomarkers are still lacking. We retrospectively enrolled MSS CRC patients receiving anti-PD-1 antibody plus VEGFRi (combination group, n=54) or VEGFRi alone (VEGFRi group, n=32), and their efficacy and safety were evaluated. We additionally examined the immune characteristics of the MSS CRC tumor microenvironment (TME) through single-cell and spatial transcriptomic data, and an MSS CRC immune cell-related signature (MCICRS) that can be used to predict the clinical outcomes of MSS CRC patients receiving immunotherapy was developed and validated in our in-house cohort. Compared with VEGFRi alone, the combination of anti-PD-1 antibody and VEGFRi exhibited a prolonged survival benefit (median progression-free survival: 4.4 vs. 2.0 months, P=0.0024; median overall survival: 10.2 vs. 5.2 months, P=0.0038) and a similar adverse event incidence. Through single-cell and spatial transcriptomic analysis, we determined ten MSS CRC-enriched immune cell types and their spatial distribution, including naive CD4⁺ T, regulatory CD4⁺ T, CD4⁺ Th17, exhausted CD8⁺ T, cytotoxic CD8⁺ T, proliferated CD8⁺ T, natural killer (NK) cells, plasma, and classical and intermediate monocytes. Based on a systemic meta-analysis and ten machine learning algorithms, we obtained MCICRS, an independent risk factor for the prognosis of MSS CRC patients. Further analyses demonstrated that the low-MCICRS group presented a higher immune cell infiltration and immune-related pathway activation, and hence a significant relation with the superior efficacy of pan-cancer immunotherapy. More importantly, the predictive value of MCICRS in MSS CRC patients receiving immunotherapy was also validated with an in-house cohort. Anti-PD-1 antibody combined with VEGFRi presented an improved clinical benefit in MSS CRC with manageable toxicity. MCICRS could serve as a robust and promising tool to predict clinical outcomes for individual MSS CRC patients receiving immunotherapy.
Humans ; Colorectal Neoplasms/drug therapy* ; Male ; Female ; Immunotherapy ; Middle Aged ; Aged ; Tumor Microenvironment/immunology* ; Retrospective Studies ; Microsatellite Instability ; Transcriptome ; Single-Cell Analysis ; Programmed Cell Death 1 Receptor/immunology* ; Gene Expression Profiling ; Immune Checkpoint Inhibitors/therapeutic use* ; Adult ; Receptors, Vascular Endothelial Growth Factor/antagonists & inhibitors*

OBJECTIVES: To explore the association of the expression of WW domain-containing ubiquitin E3 ligase 1 (WWP1) with immune infiltration in tumor microenvironment (TME) of ovarian cancer. METHODS: Ovarian cancer patient data from The Cancer Genome Atlas (TCGA) were used to analyze the association of WWP1 expression with patient prognosis. TISCH2 was utilized to analyze the changes in immune cell subtypes in TME of metastatic tumor and after chemotherapy. The impact of WWP1 on immune cell infiltration, somatic copy number alterations of WWP1 and evolution of immune cell subtypes was evaluated using TIMER and TIGER pseudo-time analysis. A deep learning model was used to analyze TCGA pathological images to investigate the effect of WWP1 on TME of ovarian cancer. RNA-seq analysis was conducted to identify the differentially expressed genes in WWP1-overexpressing SKOV3 cells and validate immune infiltration. Multicolor immunofluorescence assay was used to analyze the immune markers in SKOV3 and SKOV3/DDP cell xenografts in nude mice. RESULTS: The patients with high WWP1 expression levels had significantly lower overall survival rate (P=0.0012). High WWP1 expression levels and Stage IV disease were both associated with a poor prognosis (P<0.05). In metastatic ovarian cancer or after chemotherapy, the percentages of malignant tumor cells and tumor-associated fibroblasts increased in the TME, accompanied by elevated WWP1 levels. WWP1 expression level was positively correlated with pro-tumorigenic immunosuppressive cells (r=0.1323-0.3955, P<0.05) and negatively with tumor-inhibiting immune cells (r=-0.1949- -0.1333, P<0.05). Specific copy number alterations of WWP1 also influenced CD8⁺ T cell percentage and neutrophil infiltration levels in the TME. RNA-seq analysis of WWP1-overexpressing SKOV3 cells and immunofluorescence assay of the tumor-bearing mice yielded findings consistent with those of bioinformatics analysis. CONCLUSIONS WWP1 may serve as a prognostic biomarker and a potential target for immune regulation in the TME of ovarian cancer.
Female ; Ovarian Neoplasms/genetics* ; Humans ; Ubiquitin-Protein Ligases/metabolism* ; Tumor Microenvironment/immunology* ; Animals ; Mice ; Cell Line, Tumor ; Mice, Nude ; Prognosis ; Gene Expression Regulation, Neoplastic

Immune suppression in the tumor microenvironment (TME) is closely related to abnormal glycolysis. Tumor cells gain metabolic advantages and suppress immune responses through the "Warburg effect". Traditional Chinese medicine (TCM) has been shown to regulate key glycolysis enzymes (such as HK2 and PKM2), metabolic signaling pathways (such as PI3K/AKT/mTOR, HIF-1α) and non-coding RNAs at multiple targets, thus synergistically inhibiting lactate accumulation, improving vascular abnormalities, and relieving metabolic inhibition of immune cells. Studies have shown that TCM monomers and formulas can promote immune cell infiltration and functions, improve metabolic microenvironment, and with the assistance by the nano-delivery system, enhance the precision of treatment. However, the dynamic mechanism of the interaction between TCM-regulated glycolysis and TME has not been fully elucidated, for which single-cell sequencing and other technologies provide important technical support to facilitate in-depth analysis and clinical translational research. Future studies should be focused on the synergistic strategy of "metabolic reprogramming-immune activation" to provide new insights into the mechanisms of tumor immunotherapy.
Humans ; Tumor Microenvironment/immunology* ; Glycolysis/drug effects* ; Neoplasms/drug therapy* ; Medicine, Chinese Traditional ; Signal Transduction ; Drugs, Chinese Herbal/pharmacology*