Colorectal cancer (CRC), a major global health concern, necessitates innovative treatments. Chimeric antigen receptor (CAR) T cells have shown promises, yet they grapple with challenges. The spotlight pivots to the rising heroes: CAR natural killer (NK) cells, offering advantages such as higher safety profiles, cost-effectiveness, and efficacy against solid tumors. Nevertheless, the specific mechanisms underlying CAR NK cell trafficking and their interplay within the complex tumor microenvironment require further in-depth exploration. Herein, we provide insights into the design and engineering of CAR NK cells, antigen targets in CRC, and success in overcoming resistance mechanisms with an emphasis on the potential for clinical trials.
Colorectal Neoplasms/immunology* ; Humans ; Killer Cells, Natural/metabolism* ; Receptors, Chimeric Antigen/genetics* ; Immunotherapy, Adoptive/methods* ; Tumor Microenvironment/immunology* ; Animals

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*

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

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

Lactic acid (LA) accumulation in tumor microenvironments (TME) has been implicated in immune suppression and tumor progress. Diverse roles of LA have been elucidated, including microenvironmental pH regulation, signal transduction, post-translational modification, and metabolic remodeling. This review summarizes LA functions within TME, focusing on the effects on tumor cells, immune cells, and stromal cells. Reducing LA levels is a potential strategy to attack cancer, which inevitably affects the physiological functions of normal tissues. Alternatively, transporting LA into the mitochondria as an energy source for immune cells is intriguing. We underscore the significance of LA in both tumor biology and immunology, proposing the burning of LA as a potential therapeutic approach to enhance antitumor immune responses.
Humans ; Tumor Microenvironment/immunology* ; Neoplasms/therapy* ; Lactic Acid/immunology* ; Mitochondria/metabolism* ; Animals ; Signal Transduction

The Warburg effect, originally discovered by Otto Warburg, refers to the metabolic reprogramming of tumor cells from aerobic oxidation to glycolysis, enabling rapid energy production to support their growth and metastasis. This process is accompanied by the massive production and accumulation of lactate both intracellularly and extracellularly. The resulting acidic microenvironment impairs the normal physiological functions of immune cells and promotes tumor progression. An increasing number of studies indicate that lactate, a key metabolite in the tumor microenvironment (TME), acts as a pivotal immunosuppressive signaling molecule that modulates immune cell function. This review aims to comprehensively examine lactate's role as an immunosuppressive molecule in TME. It focuses on mechanisms such as membrane receptor binding, functional reshaping of immune cells via lactate shuttle transport, epigenetic regulation of gene expression through histone lactylation, and modulation of protein structure and function through nonhistone lactylation, emphasizing lactate's importance in immune regulation within the TME. Ultimately, this review offers novel insights into immunosuppressive therapies aimed at targeting lactate function.
Humans ; Neoplasms/metabolism* ; Tumor Microenvironment/immunology* ; Lactic Acid/immunology* ; Warburg Effect, Oncologic ; Animals ; Glycolysis ; Epigenesis, Genetic

The introduction of PD-1 blockades to chemotherapy and radiotherapy has shown promising outcomes in patients with nasopharyngeal carcinoma, but anti-PD-1 therapies are only effective in a small proportion of patients, indicating the need for reliable predictive biomarkers of benefit from immunotherapy. Here, we summarized recent advances in immunotherapy for nasopharyngeal carcinoma and studies on potential predictors that correlated with treatment response or long-term survival after immunotherapy, including biomarkers in both the tumor microenvironment and the tumor macroenvironment. Some of these biomarkers have been validated as truly predictive of immunotherapy benefit using cohorts from randomized controlled trials, while others still require further validation of their predictive value. We also summarized the challenges and future directions of biomarker studies, hopefully facilitating the development of predictive biomarkers for immunotherapy that can eventually enter clinical practice.
Humans ; Tumor Microenvironment/immunology* ; Nasopharyngeal Carcinoma/immunology* ; Immunotherapy/methods* ; Nasopharyngeal Neoplasms/immunology* ; Biomarkers, Tumor/metabolism* ; Immune Checkpoint Inhibitors/therapeutic use*

Hepatocellular carcinoma (HCC) is one of the fastest growing cancers in the world, ranking fourth among the causes of cancer-induced death in the world. At present, the field of HCC treatment is developing rapidly, and immunotherapy has been recognized as a promising treatment method, in which T cells play a key role in HCC immunotherapy. However, in the case of virus infection or in tumor microenvironment (TME), T cells will be continuously stimulated by antigens and then fall into the state of T cell exhaustion (Tex). This state will not only reduce the immunity of patients but also lead to poor efficacy of immunotherapy. Therefore, to deeply analyze the mechanism of Tex and to explore effective strategies to reverse Tex is the key point in the immunotherapy for HCC. This review aims to summarize the mechanism of Tex in HCC patients, and the current situation and shortcomings of drug research and development to reverse Tex at this stage, in order to provide theoretical basis for the optimization of immunotherapy regimen for HCC patients.
Humans ; Carcinoma, Hepatocellular/therapy* ; Liver Neoplasms/therapy* ; Immunotherapy/methods* ; T-Lymphocytes/immunology* ; Tumor Microenvironment/immunology* ; Animals ; T-Cell Exhaustion

Programmed death 1 (PD-1) and its ligand (PD-L1) serve as crucial targets in cancer immunotherapy, and their inhibitors have significantly improved the prognosis of many patients with malignant tumors. However, the issues of drug resistance and limited overall response rate associated with monotherapy remain prevalent. As a new generation of immune checkpoints, lymphocyte activation gene 3 (LAG-3) synergistically enhances the suppression of T cells alongside PD-1 in various cancers. Combining the blockade of both PD-1 and LAG-3 yields stronger anti-tumor immune effects compared to blocking either target alone, thereby reversing the immunosuppressive state of the tumor microenvironment and reducing the occurrence of resistance. This review covers the structural characteristics of LAG-3 and unveils its specific interactions with PD-1 across multiple cancers, providing a novel reference for overcoming the limitations of single-agent therapy.
Humans ; Neoplasms/immunology* ; Immunotherapy/methods* ; Programmed Cell Death 1 Receptor/metabolism* ; Lymphocyte Activation Gene 3 Protein ; Antigens, CD/metabolism* ; Animals ; Tumor Microenvironment/immunology* ; Immune Checkpoint Inhibitors/therapeutic use*