OBJECTIVES: To investigate the characteristics of immune cell infiltration in tumor samples from Chinese patients with clear cell renal cell carcinoma (ccRCC) and the correlation of immune cell infiltration with tumor stage and response to immunotherapy. METHODS: Tumor samples and clinicopathological data were collected from 154 ccRCC patients treated in Nanfang Hospital, Southern Medical University from October, 2020 to October, 2023. The immune cell types infiltrating the tumor tissues were identified using immunohistochemistry and immunofluorescence staining, and their correlations with the patients' clinicopathological characteristics were analyzed. Patient-derived tumor tissue fragment models (PDTF) models, constructed using tumor tissues from 22 patients, were treated with PD-1 monoclonal antibody, and T cell activation was detected using flow cytometry to assess the patients' responses to immunotherapy. RESULTS: In Chinese ccRCC patients included in this study, CD8⁺ T cells, CD4⁺ T cells, and CD3⁺ T cells were the most abundant in the tumor tissues. Higher infiltration levels of CD3⁺ T cells (P=0.004), PD-1⁺ T cells (P=0.020), CD68⁺ T cells (P=0.049), CD79⁺ T cells (P=0.049), and Tryptase⁺ cells (P=0.049) were all positively correlated with a larger tumor size (≥5 cm). A higher infiltration level of CD4⁺ T cells was associated with a lower tumor stage. Patients with higher International Society of Urological Pathology (ISUP) grades had higher infiltration levels of CD3⁺ T cells (P=0.023), CD8⁺ T cells (P=0.045), PD-1⁺ T cells (P=0.014), CD20⁺ B cells (P=0.020) and CD79⁺ B cells (P=0.049), and lower levels of Tryptase⁺ cells (P=0.001). Patients with abundant infiltrating immune cells tended to have better responses to immunotherapy. CONCLUSIONS The infiltrating immune cells are heterogeneous in Chinese ccRCC patients, and immune cell infiltration characteristics are closely correlated with clinicopathological parameters of the patients.
Humans ; Carcinoma, Renal Cell/pathology* ; Kidney Neoplasms/pathology* ; Immunotherapy ; Male ; Lymphocytes, Tumor-Infiltrating/immunology* ; Female ; Middle Aged ; CD8-Positive T-Lymphocytes/immunology* ; Aged ; T-Lymphocytes/immunology* ; Programmed Cell Death 1 Receptor/immunology* ; Adult ; CD4-Positive T-Lymphocytes/immunology* ; Neoplasm Staging

OBJECTIVES: To identify immunosuppressive neutrophil subsets in patients with prostate cancer (PCa) and construct a risk prediction model for prognosis and immunotherapy response of the patients based on these neutrophil subsets. METHODS: Single-cell and transcriptome data from PCa patients were collected from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA). Neutrophil subsets in PCa were identified through unsupervised clustering, and their biological functions and effects on immune regulation were analyzed by functional enrichment, cell interaction, and pseudo-time series analyses. Lasso-Cox regression was utilized to construct a prognostic risk model based on the immunosuppressive neutrophil subsets, and survival analysis and ROC curve analysis were used to compare the prognosis of PCa patients with high and low risks stratified using this model. The relationship of the prognostic risk model with PCa immune infiltration and immune response was evaluated using CIBERSORT and TIDE scores. RESULTS: PCa tissues showed a significantly greater proportion of infiltrating neutrophils than the adjacent normal tissues (P<0.05). PCa-associated neutrophils could be clustered into two independent cell subsets: Neu_1 and Neu_2. Neu_2 cells exhibited highly enriched immunoregulatory functions and were highly differentiated and mature, with upregulated immunosuppressive cytokines such as TGFB1, ITGB2, and LGALS3. Based on the genetic characteristics of Neu_2 cell subsets, the prognostic risk model was constructed. The patients in the high-risk group identified by the model had a shorter biochemical recurrence time (P<0.05) and a higher proportion of Tregs and M2-TAMs cell infiltration (P<0.05) with a higher risk of immune rejection and poorer immune response scores. CONCLUSIONS PCa-associated neutrophils are highly heterogeneous. The prognostic risk model constructed based on the immunosuppressive neutrophil Neu_2 subset can effectively predict both the survival outcomes and immune response of PCa patients.
Humans ; Male ; Prostatic Neoplasms/diagnosis* ; Prognosis ; Neutrophils/immunology* ; Immunotherapy

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*

Oral squamous cell carcinoma (OSCC) progresses from preneoplastic precursors via genetic and epigenetic alterations. Previous studies have focused on the treatment of terminally developed OSCC. However, the role of epigenetic regulators as therapeutic targets during the transition from preneoplastic precursors to OSCC has not been well studied. Our study identified lysine-specific demethylase 1 (LSD1) as a crucial promoter of OSCC, demonstrating that its knockout or pharmacological inhibition in mice reversed OSCC preneoplasia. LSD1 inhibition by SP2509 disrupted cell cycle, reduced immunosuppression, and enhanced CD4+ and CD8+ T-cell infiltration. In a feline model of spontaneous OSCC, a clinical LSD1 inhibitor (Seclidemstat or SP2577) was found to be safe and effectively inhibit the STAT3 network. Mechanistic studies revealed that LSD1 drives OSCC progression through STAT3 signaling, which is regulated by phosphorylation of the cell cycle mediator CDK7 and immunosuppressive CTLA4. Notably, LSD1 inhibition reduced the phosphorylation of CDK7 at Tyr170 and eIF4B at Ser422, offering insights into a novel mechanism by which LSD1 regulates the preneoplastic-to-OSCC transition. This study provides a deeper understanding of OSCC progression and highlights LSD1 as a potential therapeutic target for controlling OSCC progression from preneoplastic lesions.
STAT3 Transcription Factor/metabolism* ; Animals ; Histone Demethylases/genetics* ; Phosphorylation ; Mouth Neoplasms/immunology* ; Mice ; Carcinoma, Squamous Cell/immunology* ; Disease Progression ; Cyclin-Dependent Kinase-Activating Kinase ; Precancerous Conditions/metabolism* ; Humans ; Cyclin-Dependent Kinases/metabolism* ; Disease Models, Animal

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

Pyroptosis is an identified programmed cell death that has been highly linked to endoplasmic reticulum (ER) dynamics. However, the crucial proteins for modulating dynamic ER membrane curvature change that trigger pyroptosis are currently not well understood. In this study, a biotin-labeled chemical probe of potent pyroptosis inducer α-mangostin (α-MG) was synthesized. Through protein microarray analysis, reticulon-4 (RTN4/Nogo), a crucial regulator of ER membrane curvature, was identified as a target of α-MG. We observed that chemically induced proteasome degradation of RTN4 by α-MG through recruiting E3 ligase UBR5 significantly enhances the pyroptosis phenotype in cancer cells. Interestingly, the downregulation of RTN4 expression significantly facilitated a dynamic remodeling of ER membrane curvature through a transition from tubules to sheets, consequently leading to rapid fusion of the ER with the cell plasma membrane. In particular, the ER-to-plasma membrane fusion process is supported by the observed translocation of several crucial ER markers to the "bubble" structures of pyroptotic cells. Furthermore, α-MG-induced RTN4 knockdown leads to pyruvate kinase M2 (PKM2)-dependent conventional caspase-3/gasdermin E (GSDME) cleavages for pyroptosis progression. In vivo, we observed that chemical or genetic RTN4 knockdown significantly inhibited cancer cells growth, which further exhibited an antitumor immune response with anti-programmed death-1 (anti-PD-1). In translational research, RTN4 high expression was closely correlated with the tumor metastasis and death of patients. Taken together, RTN4 plays a fundamental role in inducing pyroptosis through the modulation of ER membrane curvature remodeling, thus representing a prospective druggable target for anticancer immunotherapy.
Pyroptosis/immunology* ; Humans ; Endoplasmic Reticulum/immunology* ; Animals ; Nogo Proteins/antagonists & inhibitors* ; Mice ; Cell Line, Tumor ; Xanthones/pharmacology* ; Neoplasms/pathology* ; Mice, Nude

Antibody-drug conjugates (ADCs) represent a promising class of targeted cancer therapeutics that combine the specificity of monoclonal antibodies with the potency of cytotoxic payloads. Despite their therapeutic potential, the use of ADCs faces significant challenges, including off/on-target toxicity and resistance development. This review examines the current landscape of ADC development, focusing on the critical aspects of target selection and antibody engineering. We discuss strategies to increase ADC efficacy and safety, including multitarget approaches, pH-dependent antibodies, and masked peptide technologies. The importance of comprehensive antigen expression profiling in both tumor and normal tissues is emphasized, highlighting the role of advanced technologies, such as single-cell sequencing and artificial intelligence, in optimizing target selection. Furthermore, we explore combination therapies and innovations in linker‒payload chemistry, which may provide approaches for expanding the therapeutic window of ADCs. These advances pave the way for the development of more precise and effective cancer treatments, potentially extending ADC applications beyond oncology.
Humans ; Immunoconjugates/adverse effects* ; Neoplasms/immunology* ; Animals ; Antibodies, Monoclonal/therapeutic use* ; Antineoplastic Agents/therapeutic use*

As a novel form of cell death, ferroptosis is mainly regulated by the accumulation of soluble iron ions in the cytoplasm and the production of lipid peroxides and is closely associated with several diseases, including acute kidney injury, ischemic reperfusion injury, neurodegenerative diseases, and cancer. The term "immunosuppression" refers to various factors that can directly harm immune cells' structure and function and affect the synthesis, release, and biological activity of immune molecules, leading to the insufficient response of the immune system to antigen production, failure to successfully resist the invasion of foreign pathogens, and even organ damage and metabolic disorders. An immunosuppressive phase commonly occurs in the progression of many ferroptosis-related diseases, and ferroptosis can directly inhibit immune cell function. However, the relationship between ferroptosis and immunosuppression has not yet been published due to their complicated interactions in various diseases. Therefore, this review deeply discusses the contribution of ferroptosis to immunosuppression in specific cases. In addition to offering new therapeutic targets for ferroptosis-related diseases, the findings will help clarify the issues on how ferroptosis contributes to immunosuppression.
Ferroptosis/immunology* ; Humans ; Immune Tolerance/immunology* ; Animals ; Immunosuppression Therapy ; Iron/metabolism* ; Neoplasms/immunology*

Cancer is the result of evolving crosstalk between neoplastic cell and its immune microenvironment. In recent years, immune therapeutics targeting T lymphocytes, such as immune checkpoint blockade (ICB) and CAR-T, have made significant progress in cancer treatment and validated targeting immune cells as a promising approach to fight human cancers. However, responsiveness to the current immune therapeutic agents is limited to only a small proportion of solid cancer patients. As major components of most solid tumors, myeloid cells played critical roles in regulating the initiation and sustentation of adaptive immunity, thus determining tumor progression as well as therapeutic responses. In this review, we discuss emerging data on the diverse functions of myeloid cells in tumor progression through their direct effects or interactions with other immune cells. We explain how different metabolic reprogramming impacts the characteristics and functions of tumor myeloid cells, and discuss recent progress in revealing different mechanisms-chemotaxis, proliferation, survival, and alternative sources-involved in the infiltration and accumulation of myeloid cells within tumors. Further understanding of the function and regulation of myeloid cells is important for the development of novel strategies for therapeutic exploitation in cancer.
Humans ; Tumor Microenvironment/immunology* ; Myeloid Cells/immunology* ; Neoplasms/therapy* ; Animals

Chimeric antigen receptor (CAR) T-cell therapy has shown remarkable efficacy in treating hematological malignancies and is expanding into other indications such as autoimmune diseases, fibrosis, aging and viral infection. However, clinical challenges persist in treating solid tumors, including physical barriers, tumor heterogeneity, poor in vivo persistence, and T-cell exhaustion, all of which hinder therapeutic efficacy. This review focuses on the critical role of tonic signaling in CAR-T therapy. Tonic signaling is a low-level constitutive signaling occurring in both natural and engineered antigen receptors without antigen stimulation. It plays a pivotal role in regulating immune cell homeostasis, exhaustion, persistence, and effector functions. The "Peak Theory" suggests an optimal level of tonic signaling for CAR-T function: while weak tonic signaling may result in poor proliferation and persistence, excessively strong signaling can cause T cell exhaustion. This review also summarizes the recent progress in mechanisms underlying the tonic signaling and strategies to fine-tune the CAR tonic signaling. By understanding and precisely modulating tonic signaling, the efficacy of CAR-T therapies can be further optimized, offering new avenues for treatment across a broader spectrum of diseases. These findings have implications beyond CAR-T cells, potentially impacting other engineered immune cell therapies such as CAR-NK and CAR-M.
Humans ; Immunotherapy, Adoptive/methods* ; Receptors, Chimeric Antigen/immunology* ; Signal Transduction/immunology* ; T-Lymphocytes/immunology* ; Neoplasms/immunology* ; Animals