Tumor-associated macrophage-specific CD155 contributes to M2-phenotype transition, immunosuppression, and tumor progression in colorectal cancer

Przewaquinone A, as a natural STAT3 inhibitor, suppresses the growth of melanoma cells and induces autophagy

BACKGROUND

Melanoma is a deadly malignant skin cancer with common risk factors including prolonged ultraviolet exposure. Understanding the mechanisms of signal transducer and activator of transcription (STAT3) signaling and discovering inhibitors of STAT3 signaling are considered promising melanoma treatments for melanoma. Przewaquinone A (PrA), a lipophilic diterpene quinone isolated from Salvia przewalskii Maxim. var. mandarinorum (Diels) Stib, has been shown to have neuro-protective properties. Nevertheless, it remains unclear how PrA functions in the anti-melanoma process.

PURPOSE

Herein, the aim was to investigate the suppressive action of PrA on melanoma growth and metastasis as well as the underlying mechanisms.

METHODS

The in vitro proliferation ratio, cell migration, cell invasion, cell cycle and cell apoptosis were determined using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), 5-ethynyl-2'-deoxyuridine (EdU) staining, wound-healing, transwell assays, flow cytometry and western blotting, respectively. The amount of STAT3 signaling-related proteins was determined using western blotting and immunofluorescence. The interaction between PrA and STAT3 was assessed using conducted by molecular docking, molecular dynamics (MD), surface plasmon resonance imaging (SPRi) and cellular thermal shift assay (CETSA). Autophagic fluxautophagic flux in melanoma cells was determined using the RFP-GFP-LC3 double-staining method. The STAT3C plasmid was used to overexpress STAT3 and investigate its role in the anti-melanoma action of PrA . The action of PrA on melanoma growth was validated in vivo.

RESULTS

PrA reduced cell proliferation, caused cell cycle arrest, and increased cell apoptosis, and inhibited cell migration and invasion. Additionally, PrA inhibited Src/STAT3 signaling and decreased the amount of STAT3 in the nucleus. We further confirmed that STAT3 was a direct target of PrA using molecular docking, MD, SPRi assay and CETSA. Additionally, STAT3 overexpression partially blocked the anti-melanoma effects of PrA. PrA induced autophagy in melanoma cells via STAT3 signaling. Moreover, combination with the autophagy inhibitors CQ (chloroquine) or 3MA (3-methyladenine) enhanced its anti-melanoma effects. PrA inhibited tumor growth and suppressed STAT3 signaling in vivo.

CONCLUSION

These findings collectively demonstrated that PrA inhibits the growth and metastasis of melanoma cells and induces protective autophagy of melanoma cells by inhibiting STAT3 signaling. Therefore, PrA may be a viable candidate for the treatment of melanoma and the results of this study may help to guide the development of new therapeutic approaches for patients with melanoma.

Preclinical application of a CD155 targeting chimeric antigen receptor T cell therapy for digestive system cancers

Despite intensive multimodal therapy, the prognosis for patients with digestive system cancers remains poor. Cancer cell heterogeneity and immunosuppressive microenvironments are the main barriers to the effective CAR-T cell therapy with solid malignancies. In parallel, tumor-associated macrophages (TAMs) are essential for tumor immunosuppressive microenvironment formation. The limited efficacy of CAR-T cell therapy with solid malignancies prompted us to test whether new therapeutic target could enhance the antitumor activity of CAR-T cells with several digestive system cancer types. We determined CD155 expression in multiple human digestive system cancers, including gastric cancer, esophagus cancer, pancreatic cancer, and colon cancer, normal tissue samples and patient-derived M2-like tumor-associated macrophages. We developed a CD155-based CAR comprising the extracellular domain of human TIGIT, 4-1BB, and CD3z signaling domains (BBz). Furthermore, we validated the killing efficacy and safety of CD155-BBz CAR-T cells in vitro and in vivo using in-house established preclinical tumor models. CD155 was strongly and homogenously expressed in digestive system cancers but mildly in normal tissues, indicating it could be an ideal target for CAR-T cell therapy, moreover, TAMs that express CD155 possess an immunosuppressive M2-like profile. We found that CD155-BBz CAR-T cells can mediate significant antitumor activity in vivo, which induces complete tumor regression and long-lasting immunologic memory of established solid tumors in xenograft models. Our study indicates that CD155 is a promising target for digestive system cancer therapy, and CD155-targeting CAR-T cells perform a detecting power in digestive system cancer clinical trials.

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

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

Lactate-mediated metabolic reprogramming of tumor-associated macrophages: implications for tumor progression and therapeutic potential

The tumor microenvironment (TME) is characterized by distinct metabolic adaptations that not only drive tumor progression but also profoundly influence immune responses. Among these adaptations, lactate, a key metabolic byproduct of aerobic glycolysis, accumulates in the TME and plays a pivotal role in regulating cellular metabolism and immune cell function. Tumor-associated macrophages (TAMs), known for their remarkable functional plasticity, serve as critical regulators of the immune microenvironment and tumor progression. Lactate modulates TAM polarization by influencing the M1/M2 phenotypic balance through diverse signaling pathways, while simultaneously driving metabolic reprogramming. Furthermore, lactate-mediated histone and protein lactylation reshapes TAM gene expression, reinforcing their immunosuppressive properties. From a therapeutic perspective, targeting lactate metabolism has shown promise in reprogramming TAMs and enhancing anti-tumor immunity. Combining these metabolic interventions with immunotherapies may further augment treatment efficacy. This review underscores the crucial role of lactate in TAM regulation and tumor progression, highlighting its potential as a promising therapeutic target in cancer treatment.

Identification of the "Collagen-Macrophage" sub-category of patients with colorectal cancer as an extension of the CMS4 subtype with THBS2 as a therapeutic target

We identified a subset of patients with colorectal cancer (CRC) enriched with "collagen-TAMs," designated the CM class, using large integrated colon cancer transcriptome and single-cell transcriptome datasets. This classification system could be used as an extension of the traditional CMS classification system for CRC to guide more accurate classification and treatment.We also screened CAF-derived THBS2 as a potential biomarker for CM and found that it plays an important role in CRC disease models in vitro and in vivo, promoting tumor development and metastasis as well as TAM recruitment. Targeting THBS2 combined with PD-1 therapy effectively improved the therapeutic effect of immunotherapy in vivo. The CM classification provides a new perspective for CRC treatment, and THBS2, which is highly expressed in CM cases, can be used as a new potential combined target for immunotherapy.

APOC1 expressed in macrophages promotes the pulmonary metastasis of colorectal cancer via CCL2/CCL5

Metastasis is the main cause of death in colorectal cancer (CRC), and the lungs are common sites of metastasis. However, there is little effective target to intervene colorectal cancer pulmonary metastasis (CCPM), especially on its unique immune microenvironment. In this study, sixteen genes were identified as core CCPM-related differentially expressed genes (DEGs) between CRC and CCPM. Three genes including Apolipoprotein C1 (APOC1) were associated with prognosis, stage and metastasis of CRC. In immunohistochemistry, APOC1 was mainly expressed in macrophages, and expressed more in CCPM than CRC. Patients with synchronous CCPM, higher stage, poorer OS and CCPM-free interval tended to have higher expression. In experiments in vitro, knockdown of APOC1 in macrophages reduced the migration, invasion, and epithelial-mesenchymal transition of CRC cells. Knockdown of APOC1 in macrophages significantly decreased secretion of chemokines like CCL2 and CCL5. The pro-metastatic effect of macrophages expressing APOC1 was partially blocked by the antibodies of CCL2 and CCL5. Activation of STAT3 was a key process in APOC1's regulation of CCL2 and CCL5. In experiments in vivo, knockdown of APOC1 in macrophages reduced pulmonary metastasis. To conclude, APOC1 is one of core CCPM-related DEGs and associated with the metastasis and survival of CRC. Macrophages expressing APOC1 promote the CCPM by APOC1-STAT3-CCL2/CCL5 axis. APOC1 and macrophages expressing APOC1 play vital roles and may be potential therapeutic targets in CCPM.

Reciprocal Modulation of Tumour and Immune Cell Motility: Uncovering Dynamic Interplays and Therapeutic Approaches

Dysregulated cell movement is a hallmark of cancer progression and metastasis, the leading cause of cancer-related mortality. The metastatic cascade involves tumour cell migration, invasion, intravasation, dissemination, and colonisation of distant organs. These processes are influenced by reciprocal interactions between cancer cells and the tumour microenvironment (TME), including immune cells, stromal components, and extracellular matrix proteins. The epithelial-mesenchymal transition (EMT) plays a crucial role in providing cancer cells with invasive and stem-like properties, promoting dissemination and resistance to apoptosis. Conversely, the mesenchymal-epithelial transition (MET) facilitates metastatic colonisation and tumour re-initiation. Immune cells within the TME contribute to either anti-tumour response or immune evasion. These cells secrete cytokines, chemokines, and growth factors that shape the immune landscape and influence responses to immunotherapy. Notably, immune checkpoint blockade (ICB) has transformed cancer treatment, yet its efficacy is often dictated by the immune composition of the tumour site. Elucidating the molecular cross-talk between immune and cancer cells, identifying predictive biomarkers for ICB response, and developing strategies to convert cold tumours into immune-active environments is critical to overcoming resistance to immunotherapy and improving patient survival.

Expression of the TIGIT axis and the CD39/CD73 purinergic pathway in bone metastasis-derived immune cells

BACKGROUND

Bone metastases (BM) represent one of the most common sites of metastasis. The study aimed to compare the composition of immune cell infiltration from aspirates of different BM prior to systemic therapy.

METHOD

Phenotypic and functional analyses were conducted via multiparametric flow cytometry (MFC) on BM-derived aspirates obtained from patients with breast cancer (BC, n = 6), patients with prostate cancer (PC, n = 5), patients with non-small-cell lung cancer (NSCLC) (n = 7), patients with myeloma (MM, n = 10) and bone aspirates from age-matched non-malignant controls (NMC, n = 10).

RESULTS

Across all tumors aspirates the fraction of CD8+ T cells was reduced. In contrast, infiltration by immunosuppressive CD56+CD16-NK and CD163+CD86+ M2-like macrophages was increased in BM compared to NMC aspirates. BM-derived CD8+ T cells aberrantly co-expressed TIGIT with PVRIG or CD39. Similarly, BM-derived cytotoxic NK cells co-expressed TIGIT and PVRIG. In addition, BM-derived M2-like macrophages exhibited an increased subset of cells co-expressing either TIGIT and PVRL4 or CD112 and CD155. Using a myeloma model, functional in vitro studies showed that blockade of TIGIT and CD39 leads to increased PBMC-mediated lysis of myeloma cells.

CONCLUSION

The study shows that an altered immune cell composition is present in BM across the different tumor entities. Additionally, molecules of the TIGIT checkpoint as well as of the purinergic pathway are aberrantly expressed by BM-infiltrating CD8+ T cells, NK cells and macrophages and also functionally relevant for tumor cell lysis.

Immunomodulatory behavior of CircRNAs in tumor microenvironment

Circular RNAs (circRNAs) are a type of non coding RNA that possess unique single stranded circular structures formed through reverse splicing mechanisms. Due to the lack of a free end that is typically susceptible to degradation by nucleases, circular RNAs exhibit resistance to ribonuclease R, making them highly stable in eukaryotic cells. The complex relationship between circRNA dysregulation and various pathophysiological conditions, especially cancer. Tumor microenvironment (TME) is a collective term for various components surrounding tumors and is an important factor affecting tumor development. Simultaneous infiltration of TME by different types of immune cells; These immune cells interact with the TME, collectively forming the so-called "tumor immune microenvironment". The complex interactions between tumor cells and TME profoundly affect the behavior of malignant tumors, and circRNAs derived from tumor cells and TME cell components have become important mediators of immune response and evasion within the TME. CircRNAs can directly or indirectly regulate immune cells, thereby modulating anti-tumor immunity. This review highlights how circRNAs, especially those encapsulated in extracellular vesicles like exosomes, influence the differentiation, chemotaxis, and anti-tumor immune functions of immune cells within the TME. Metabolic reprogramming plays an important role in this process. The process of circRNAs regulating tumor immunity is affected by multiple factors, such as hypoxia and viral infection. This review emphasizes the roles of the interaction between circRNAs and the TME in tumor immune regulation and prospects the guiding significance of circRNAs in tumor immune checkpoint therapy.

The role of glycan-lectin interactions in the tumor microenvironment: immunosuppression regulators of colorectal cancer

Colorectal cancer (CRC) is a common malignant tumour and a serious global health issue. Glycosylation, a type of posttranslational modification, has been extensively studied in relation to cancer growth and metastasis. Aberrant glycosylation alters how the immune system in the microenvironment perceives the tumour and drives immune suppression through glycan-binding receptors. Interestingly, specific glycan signatures can be regarded as a new pattern of immune checkpoints. Lectins are a group of proteins that exhibit high affinity for glycosylation structures. Lectins and their ligands are found on endothelial cells (ECs), immune cells and tumour cells and play important roles in the tumour microenvironment (TME). In CRC, glycan-lectin interactions can accelerate immune evasion promoting the differentiation of tumour-associated M2 macrophages, altering T cell, dendritic cell (DC), natural killer (NK) cell, and regulatory T (Treg) cell activity to modify the functions of antigen-presenting cells functions. Here, we review our current knowledge on how glycan-lectin interactions affect immune-suppressive circuits in the TME and discuss their roles in the development of more effective immunotherapies for CRC.

CTHRC1: a key player in colorectal cancer progression and immune evasion

The multifunctional secreted protein, collagen triple helix repeat containing 1 (CTHRC1), has recently emerged as a significant focus within oncology research. CTHRC1 expression in tumors is governed by a complex interplay of regulatory signals, including methylation, glycosylation, and notably, non-coding RNAs, which constitute its predominant regulatory mechanism. Colorectal cancer (CRC), a highly prevalent epithelial malignancy, sees CTHRC1 influencing tumor progression and metastasis through its modulation of several downstream signaling cascades, such as Wnt/PCP, TGF-β/Smad, and MEK/ERK pathways. Furthermore, CTHRC1 contributes to immune evasion in CRC via diverse mechanisms. It is intricately associated with macrophage phenotypic switching within the tumor microenvironment (TME), favoring M2 macrophage polarization and facilitating the infiltration of T cells and neutrophils. CTHRC1 is also instrumental in immune escape by driving the remodeling of the extracellular matrix through interactions with cancer-associated fibroblasts. Additionally, CTHRC1's roles extend to the regulation of hypoxia-related pathways, metabolism of glycolysis and fatty acids, and involvement in tumor angiogenesis, all of which support tumor immune evasion. Considering its multifaceted activities, CTHRC1 emerges as a promising therapeutic target in CRC, with the potential to enhance the outcomes of existing radiotherapeutic and immunotherapeutic regimens. This review endeavors to delineate the mechanistic and therapeutic landscapes of CTHRC1 in CRC. Through a comprehensive discussion of CTHRC1's diverse functions, we aim to provide insights that could pave the way for innovative approaches in cancer therapy.

ITGB5 is a prognostic factor in colorectal cancer and promotes cancer progression and metastasis through the Wnt signaling pathway

Integrin beta5 (ITGB5) expression levels are dysregulated in a variety of cancers. However, the mechanism and clinical value of ITGB5 in colorectal cancer (CRC) remain unclear. The Gene Expression Omnibus (GEO) database, real-time PCR, Western blotting and immunohistochemistry were utilized to evaluate ITGB5 expression levels in CRC tissue. Clinical data from the GEO database were obtained to further explore the associations of ITGB5 with clinical features and patient survival. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis and gene set enrichment analysis (GSEA) were performed to explore the functions and signaling pathways of ITGB5. In addition, ITGB5 expression was inhibited by siRNA, and the roles of ITGB5 in SW480 and RKO cell growth, migration and invasion, as well as in the Wnt/β-catenin signaling pathway, were investigated. Pancancer studies have shown that ITGB5 is highly expressed in a variety of cancers. Moreover, ITGB5 expression is significantly increased in CRC tissues and is correlated with TNM stage, invasion depth, lymph node metastasis and distant metastasis stage. Kaplan-Meier analysis and meta-analysis of the GSE39582 and GSE17538 datasets indicated that a high level of ITGB5 is a high risk factor for overall survival (OS) and disease-free survival (DFS). In addition, receiver operating characteristic (ROC) curve analysis revealed the value of ITGB5 in predicting DFS, and univariate and multivariate analyses showed that ITGB5 may be an independent prognostic factor for DFS. GO and KEGG analyses indicated that many GO terms related to the extracellular matrix (ECM), focal adhesion and ECM-receptor interaction pathways were enriched. GSEA revealed focal adhesion, cancer pathways, ECM-receptor interactions and Wnt signaling pathways in the samples with high ITGB5 expression. Correlation analysis revealed that high ITGB5 expression is significantly correlated with the TGF-β/EMT pathway and WNT targets. Silencing of ITGB5 inhibited SW480 and RKO cell proliferation, invasion and migration. Mechanistically, downregulated ITGB5 expression blocked the Wnt/β-catenin signaling pathway and epithelial-mesenchymal transition (EMT) in CRC cells. Moreover, ITGB5 expression was related to M0 macrophages, M2 macrophages, neutrophils and plasma cell fractions. ITGB5 may be associated with poor prognosis and metastasis in patients with CRC. ITGB5 may hold promise as a prognostic biomarker and a new potential therapeutic target for CRC.

Integration of histopathological images and immunological analysis to predict M2 macrophage infiltration and prognosis in patients with serous ovarian cancer

Objective

Investigating the effect of M2 macrophage infiltration on overall survival and to use histopathological imaging features (HIF) to predict M2 macrophage infiltration in patients with serous ovarian cancer (SOC) is important for improving prognostic accuracy, identifying new therapeutic targets, and advancing personalized treatment approaches.

Methods

We downloaded data from 86 patients with SOC from The Cancer Genome Atlas (TCGA) and divided these patients into a training set and a validation set with a ratio of 8:2. In addition, tissue microarrays from 106 patients with SOC patients were included as an external validation set. HIF were recognized by deep multiple instance learning (MIL) to predict M2 macrophage infiltration via theResNet18 network in the training set. The final model was evaluated using the internal and external validation set.

Results

Using data acquired from the TCGA database, we applied univariate Cox analysis and determined that higher levels of M2 macrophage infiltration were associated with a poor prognosis (hazard ratio [HR]=6.8; 95% CI [confidence interval]: 1.6-28, P=0.0083). External validation revealed that M2 macrophage infiltration was an independent risk factor for the prognosis of patients with SOC (HR=3.986; 95% CI: 2.436-6.522; P<0.001). Next, we constructed four MIL strategies (Mean probability, Top-10 Mean, Top-100 Mean, and Maximum probability) to identify histopathological images that could predict M2 macrophage infiltration. The Mean Probability Method was the most suitable and was used to generate a HIF model with an AUC, recall rate, precision and F1 score of 0.7500, 0.6932, 0.600, 0.600, and 0.600, respectively.

Conclusions

Collectively, our findings indicated that M2 macrophage infiltration may increase prognostic prediction for SOC patients. Machine deep learning of pathological immunohistochemical images exhibited good potential for the direct prediction of M2 macrophage infiltration.

Tissue macrophages: origin, heterogenity, biological functions, diseases and therapeutic targets

Macrophages are immune cells belonging to the mononuclear phagocyte system. They play crucial roles in immune defense, surveillance, and homeostasis. This review systematically discusses the types of hematopoietic progenitors that give rise to macrophages, including primitive hematopoietic progenitors, erythro-myeloid progenitors, and hematopoietic stem cells. These progenitors have distinct genetic backgrounds and developmental processes. Accordingly, macrophages exhibit complex and diverse functions in the body, including phagocytosis and clearance of cellular debris, antigen presentation, and immune response, regulation of inflammation and cytokine production, tissue remodeling and repair, and multi-level regulatory signaling pathways/crosstalk involved in homeostasis and physiology. Besides, tumor-associated macrophages are a key component of the TME, exhibiting both anti-tumor and pro-tumor properties. Furthermore, the functional status of macrophages is closely linked to the development of various diseases, including cancer, autoimmune disorders, cardiovascular disease, neurodegenerative diseases, metabolic conditions, and trauma. Targeting macrophages has emerged as a promising therapeutic strategy in these contexts. Clinical trials of macrophage-based targeted drugs, macrophage-based immunotherapies, and nanoparticle-based therapy were comprehensively summarized. Potential challenges and future directions in targeting macrophages have also been discussed. Overall, our review highlights the significance of this versatile immune cell in human health and disease, which is expected to inform future research and clinical practice.

The colorectal cancer microenvironment: Preclinical progress in identifying targets for cancer therapy

Colorectal cancer (CRC) is a common cancer with high mortality rates. Despite progress in treatment, it remains an incurable disease for many patients. In CRC, the tumor microenvironment (TME) plays critical roles in tumor growth, progression, patients' prognosis, and response to treatments. Understanding TME complexities is important for developing effective therapies. In vitro and in vivo preclinical models are critical in understanding the disease, discovering potential targets, and developing effective therapeutics. In this review, we focus on preclinical research studies associated with modulation of the TME in CRC. These models give insights into understanding the role of stroma and immune cell components of the TME in CRC and improve clinical responses, providing insights in novel treatment options. Various studies have focused on targeting the TME in CRC to improve responses to different therapeutic approaches. These include identifying targets for cancer therapies, targeting molecular signaling, and enhancing the efficacy of immunotherapeutic modalities. Furthermore, targeting stromal and angiogenic factors in the TME may provide new therapeutic options. Overall, understanding and targeting the TME in CRC is a promising approach for improving therapeutic outcomes.

CD155 promotes the advancement of hepatocellular carcinoma by suppressing the p53-mediated ferroptosis via interacting with CD96

This work researched the influence and mechanism of CD155 on hepatocellular carcinoma advancement. CD155 expression and its effect on survival of hepatocellular carcinoma patients were analyzed based on the GEPIA2 database. String software predicted the interacting between CD155 and CD96, which was further verified by co-immunoprecipitation experiment. The function of CD155 and CD96 on the proliferation, migration, and invasion of hepatocellular carcinoma cells (HCC) was explored by colony formation, wound healing, and transwell assays. To research the effect of CD155 and CD96 on ferroptosis, ferroptosis-related factors in HCC were investigated. CD155 and p53 were both silenced in HCC to explore whether CD155 regulates hepatocellular carcinoma progression by acting on p53. Xenograft tumor study was conducted to examine the impact of CD155 on the in vivo growth of HCC. It was discovered that, CD155 up-regulation predicted poor survival of hepatocellular carcinoma patients. CD155 could be interacted with CD96. The proliferation, migration, and invasion of HCC were heightened by CD155. However, ferroptosis was suppressed by CD155, as CD155 decreased p53 and iron but increased SLC7A11, GPX4 and GSH in HCC. In fact, CD96 silencing abolished these effects of CD155. The suppressed malignant behaviors and the enhanced ferroptosis in HCC induced by CD155 silencing were abrogated by p53 silencing. In vivo, CD155 silencing suppressed growth and enhanced ferroptosis of hepatocellular carcinoma, which were counteracted by p53 silencing. Thus, CD155 might facilitate hepatocellular carcinoma advancement through blocking the p53-mediated ferroptosis via interacting with CD96. CD155 might be a promising target for treating hepatocellular carcinoma. KEY MESSAGES: CD155 was up-regulated in hepatocellular carcinoma, predicting poor survival. CD155 protein could be interacted with CD96 protein. Proliferation and invasion of liver cancer cells were facilitated by CD155. Proliferation and invasion of liver cancer cells were decreased by CD96 loss. CD155 promoted liver cancer by suppressing p53-mediated ferroptosis via CD96.

Hypoxia-Associated GPNMB+ Macrophages Promote Malignant Progression of Colorectal Cancer and Its Related Risk Signature Are Powerful Predictive Tool for the Treatment of Colorectal Cancer Patients

Colorectal cancer (CRC) is a highly malignant tumor with hypoxia being a crucial feature during its progression. This study utilized multiple independent CRC cohorts for bioinformatics analysis and in vitro experiments to investigate the role of hypoxia-related subgroups in CRC. Machine learning was employed to construct risk features associated with this subgroup and further explore its therapeutic value in CRC. The study identified the GPNMB+ Macrophage (GPNMB+ Macr) subgroup as most relevant to hypoxia. GPNMB+ Macr showed significantly higher infiltration in tumor tissues compared to non-tumor tissues, increasing with CRC stage. High infiltration of GPNMB+ Macr was associated with poor prognosis in terms of overall and recurrence-free survival in CRC patients. GPNMB+ Macrophages exhibit M2-like characteristics and have the ability to promote 5-FU resistance, proliferation, and metastasis of CRC cells. The study developed the Hypoxia-Related Macrophage Risk Score (HMRS), which not only served as an independent prognostic factor for CRC patients but also demonstrated robust prognostic performance compared to 84 previously published prognostic features. Patients with low HMRS were sensitive to fluorouracil, oxaliplatin (FOLFOX), and anti-PD-1 immunotherapy, while those with high HMRS showed resistance. Additionally, HMRS was identified as an independent prognostic factor in other digestive tract tumors (hepatocellular carcinoma, pancreatic cancer, esophageal cancer, and gastric cancer), indicating potential extrapolation to other tumor types. In conclusion, GPNMB+ Macr promotes the malignant progression of CRC, and HMRS serves as a powerful predictive tool for prognosis, chemotherapy, and immunotherapy in CRC patients, aiding in improving the quality of survival.

CD155 promotes the progression of colorectal cancer by restraining CD8+ T cells via the PI3K/AKT/NF-κB pathway

BACKGROUND

CD155 is a crucial factor in the regulation of T cell function and contributes to immune escape. CD155 upregulation has been found in several types of cancer. However, the mechanism by which CD155 regulates CD8+ T cell function in colorectal cancer remains unclear. Here we investigated the role and mechanism of CD155 in the regulation of CD8+ T cell function.

METHODS

We studied the expression of CD155 in colorectal cancer tissues through western blot, immunohistochemistry, and the TCGA database. We verified the effects of CD155 on the functions of colorectal cancer cells and CD8+ T cells through in vitro experiments. We demonstrated that CD155 affects CD8+ T cell migration and thus promotes tumor growth in a mouse subcutaneous tumor model. We then tested the changes in the PI3K/AKT/NF-κB pathway in CD8+ T cells by flow cytometry.

RESULTS

We demonstrated that stable CD155 expression was negatively correlated with prognosis in colorectal cancer patients. In vitro experiments confirmed that CD155 does not affect tumor cell proliferation, migration, or invasion. We also revealed that CD155 downregulated the function and migration of CD8+ T cells in vivo and in vitro. Furthermore, CD155 might regulate CD8+ T cells function via the PI3K/AKT/NF-κB pathway.

CONCLUSION

This study revealed that CD155 can promote the progression of colorectal cancer by regulating the PI3K / AKT-NF-κB pathway to promote the depletion of CD8+ T cells and reduce their migration to the tumor microenvironment. CD155 may become an important prognostic biomarker and an effective target for colorectal cancer immunotherapy.

Yanghe decoction inhibits inflammation-induced lung metastasis of colorectal cancer

ETHNOPHARMACOLOGICAL RELEVANCE

Positive deficiency and cancer toxicity are the main pathogenesis of colorectal cancer (CRC) lung metastasis. Yanghe decoction (YHD), a traditional Chinese medicine, has the effects of warming yang, tonifying blood, dispersing cold and clearing stagnation, adopting a treatment method that combines supporting the right and dispelling the wrong, which has remarkable efficacy in anti-tumor.Although, its precise mechanism of inhibiting the metastasis of colorectal cancer to the lung is still poorly understood.

AIM OF THE STUDY

This study aimed to elucidate the antitumor properties of YHD within the context of colorectal cancer lung metastasis.

MATERIALS AND METHODS

Ultrahigh-performance liquid chromatography coupled with mass spectrometry (UHPLC-MS) was utilized to analyze the chemical composition of YHD. The anticancer activity of YHD was evaluated in a CRC lung metastasis mouse model by quantifying pulmonary metastatic nodules. The effects of YHD on CRC cell proliferation, apoptosis, cell cycle progression, and invasion were assessed using CCK-8 assays, flow cytometry, and Transwell assays. YHD-mediated immune modulation in tumor-bearing mice was evaluated by analyzing antitumor immunity, immunosuppressive cells, and cytokines in peripheral blood and tumor tissue. Gut microbiota analysis was conducted to determine the impact of YHD on the gut microbiota in mice.

RESULTS

Our analysis identified 1801 chemical markers in YHD. CFA exacerbated lung metastasis in CRC, whereas oral administration of YHD significantly mitigated this effect, as evidenced by the reduced number of metastatic lung nodules in CRC tumor-bearing mice. In vitro experiments demonstrated that YHD inhibits CRC cell proliferation, induces apoptosis, and suppresses invasion. In the lung tissues of mice with CRC metastasis treated with CFA, there was a significant reduction in NK cells and IL-21, along with an increase in M2 macrophages and IL-6. Following YHD treatment, there was a notable increase in NK cells and IL-21, accompanied by a decrease in M2 macrophages and IL-6 in lung tissues. YHD administration was also associated with an increase in beneficial bacterial species such as Bacillus and a decrease in deleterious bacterial species such as Oscillibacter.

CONCLUSION

Our findings demonstrate that YHD inhibits lung metastasis in CRC by suppressing CRC cell proliferation and invasion, in addition to modulating the tumor microenvironment to favor antitumor immunity. These results provide a scientific basis for the clinical application of YHD in the treatment of CRC patients.

Clinical significance of CD155 expression in surgically resected lung squamous cell carcinoma

BACKGROUND

Cluster of differentiation 155 (CD155) is expressed in many tumor types. CD155 is involved in the immune avoidance of tumor cells and contributes to tumor development and progression. Therefore, CD155 is a novel target for cancer immunotherapy. The clinical significance of CD155 expression in lung squamous cell carcinoma (LUSC) has not been fully elucidated.

MATERIALS AND METHODS

We performed a retrospective analysis of 264 patients with surgically resected LUSC. Immunohistochemistry was used to evaluate CD155 expression. The association of CD155 expression with clinicopathological features and clinical outcomes was assessed. We also analyzed the relationship between CD155 expression and programmed cell death-ligand 1 (PD-L1) expression and tumor-infiltrating lymphocytes.

RESULTS

Among the 264 patients, 137 patients (51.9%) were classified in the high CD155 expression group. High CD155 expression was significantly associated with pleural invasion, vascular invasion, PD-L1 positivity, and high CD3, CD4, and CD8 expressions. In multivariate analysis, the presence of pleural invasion and PD-L1 positivity were independent predictors of high CD155 expression. Kaplan-Meier curve analysis showed that high CD155 expression was significantly associated with shorter disease-free survival and overall survival. In multivariate analysis, high CD155 expression was an independent poor prognostic factor for overall survival, but not for disease-free survival. Subgroup analyses revealed that the prognostic effect of CD155 expression was observed in the PD-L1 positive group but not the PD-L1 negative group.

CONCLUSION

Our analysis revealed that high CD155 expression significantly predicted poor prognosis in patients with surgically resected LUSC, especially in patients with PD-L1-positive tumors.

Myeloid cells meet CD8+ T cell exhaustion in cancer: What, why and how

Exhausted T cell (Tex) is a specific state of T cell dysfunction, in which these T cells gradually lose their effector function and change their phenotype during chronic antigen stimulation. The enrichment of exhausted CD8+ T cell (CD8+ Tex) in the tumor microenvironment is one of the important reasons leading to the poor efficacy of immunotherapy. Recent studies have reported many reasons leading to the CD8+ T cell exhaustion. In addition to cancer cells, myeloid cells can also contribute to T cell exhaustion via many ways. In this review, we discuss the history of the concept of exhaustion, CD8+ T cell dysfunction states, the heterogeneity, origin, and characteristics of CD8+ Tex. We then focus on the effects of myeloid cells on CD8+ Tex, including tumor-associated macrophages (TAMs), dendritic cells (DCs) and neutrophils. Finally, we systematically summarize current strategies and recent advancements in therapies reversing and CD8+ T cell exhaustion.

FSTL1 sustains glioma stem cell stemness and promotes immunosuppressive macrophage polarization in glioblastoma

Tumor-associated macrophages (TAMs) within the tumor microenvironment (TME) play a crucial role in glioblastoma (GBM) progression by interacting with glioma stem cells (GSCs). These interactions lead to the polarization of TAMs toward an M2 phenotype, which, in turn, enhances the stem-like traits and malignant progression of GSCs. Our study shows that FSTL1, a protein released by GSCs, is significantly elevated in gliomas and linked to the progression of the disease. By suppressing FSTL1 in a mouse model, we observed reduced tumor growth and a decrease in M2 macrophages. In vitro studies show that FSTL1 from GSCs promotes M2 polarization and infiltration. Importantly, GSCs utilize autocrine FSTL1 to interact with TLR2, which inhibits the endocytosis-lysosomal degradation pathway mediated by EGFR, resulting in the activation of the PI3K-AKT signaling pathway that is critical for maintaining their self-renewal. These findings underscore the importance of FSTL1 in GSC maintenance and M2 macrophage polarization, suggesting that interventions targeting the FSTL1/TLR2 pathway could provide a novel therapeutic approach for GBM patients.

The implications for urological malignancies of non-coding RNAs in the the tumor microenvironment

Urological malignancies are a major global health issue because of their complexity and the wide range of ways they affect patients. There's a growing need for in-depth research into these cancers, especially at the molecular level. Recent studies have highlighted the importance of non-coding RNAs (ncRNAs) – these don't code for proteins but are crucial in controlling genes – and the tumor microenvironment (TME), which is no longer seen as just a background factor but as an active player in cancer progression. Understanding how ncRNAs and the TME interact is key for finding new ways to diagnose and predict outcomes in urological cancers, and for developing new treatments. This article reviews the basic features of ncRNAs and goes into detail about their various roles in the TME, focusing specifically on how different ncRNAs function and act in urological malignancies.

Current status of research on the mechanisms of tumor-associated macrophages in esophageal cancer progression

Esophageal carcinoma (EC) is one of the most common tumors in China and seriously affects patient survival and quality of life. In recent years, increasing studies have shown that the tumor microenvironment is crucial in promoting tumor progression and metastasis. Tumor-associated macrophages (TAM) are key components of the tumor immune microenvironment and promote both tumor growth and antitumor immunity. Much evidence suggests that TAMs are closely associated with esophageal tumors. However, understanding of the clinical value and mechanism of action of TAM in esophageal cancer remains limited. Therefore, we reviewed the status of research on the role and mechanism of action of TAM in EC progression and summarized its potential clinical application value to provide a theoretical basis for the clinical treatment of EC.

Dynamics of the immune microenvironment and immune cell PANoptosis in colorectal cancer: recent advances and insights

Colorectal cancer (CRC) is one of the most significant oncological threats to human health globally. Patients often exhibit a high propensity for tumor recurrence and metastasis post-surgery, resulting in suboptimal prognoses. One of the underlying reasons for the metastatic potential of CRC is the sustained abnormal state of the tumor immune microenvironment, particularly characterized by the atypical death of critical immune cells. In recent years, a novel concept of cell death known as PANoptosis has emerged. This form of cell death is regulated by the PANoptosome complex and encompasses key features of apoptosis, pyroptosis, and necroptosis, yet cannot be entirely substituted by any of these processes alone. Due to its widespread occurrence and complex mechanisms, PANoptosis has been increasingly reported in various malignancies, enhancing our understanding of its pathological mechanisms, particularly in the context of CRC. However, the characteristics of immune cell PANoptosis within the CRC immune microenvironment have not been thoroughly elucidated. In this review, we focus on the impact of CRC progression on various immune cell types and summarize the distinctive features of immune cell PANoptosis. Furthermore, we highlight the future research trends and challenges associated with the mechanisms of immune cell PANoptosis in CRC.

Macrophages in tumor cell migration and metastasis

Tumor-associated macrophages (TAMs) are a phenotypically diverse, highly plastic population of cells in the tumor microenvironment (TME) that have long been known to promote cancer progression. In this review, we summarize TAM ontogeny and polarization, and then explore how TAMs enhance tumor cell migration through the TME, thus facilitating metastasis. We also discuss how chemotherapy and host factors including diet, obesity, and race, impact TAM phenotype and cancer progression. In brief, TAMs induce epithelial-mesenchymal transition (EMT) in tumor cells, giving them a migratory phenotype. They promote extracellular matrix (ECM) remodeling, allowing tumor cells to migrate more easily. TAMs also provide chemotactic signals that promote tumor cell directional migration towards blood vessels, and then participate in the signaling cascade at the blood vessel that allows tumor cells to intravasate and disseminate throughout the body. Furthermore, while chemotherapy can repolarize TAMs to induce an anti-tumor response, these cytotoxic drugs can also lead to macrophage-mediated tumor relapse and metastasis. Patient response to chemotherapy may be dependent on patient-specific factors such as diet, obesity, and race, as these factors have been shown to alter macrophage phenotype and affect cancer-related outcomes. More research on how chemotherapy and patient-specific factors impact TAMs and cancer progression is needed to refine treatment strategies for cancer patients.

Probiotic nucleotides increase IL-10 expression in airway macrophages to mitigate airway allergy

BACKGROUND

Dysfunctional immune regulation plays a crucial role in the pathogenesis of airway allergies. Macrophages are one of the components of the immune regulation cells. The aim of this study is to elucidate the role of lysine demethylase 5 A (KDM5A) in maintaining macrophages' immune regulatory ability.

METHODS

DNA was extracted from Lactobacillus rhamnosus GG to be designated as LgDNA. LgDNA was administered to the mice through nasal instillations. M2 macrophages (M2 cells) were isolated from the airway tissues using flow cytometry.

RESULTS

We found that airway M2 cells of mice with airway Th2 polarization had reduced amounts of IL-10 and KDM5A. Mice with Kdm5a deficiency in M2 cells showed the airway Th2 polarization. The expression of Kdm5a in airway M2 cells was enhanced by nasal instillations containing LgDNA. KDM5A mediated the effects of LgDNA on inducing the Il10 expression in airway M2 cells. Administration of LgDNA mitigated experimental airway allergy.

CONCLUSIONS

M2 macrophages in the airway tissues of mice with airway allergy show low levels of KDM5A. By upregulating KDM5A expression, LgDNA can increase Il10 expression and reconcile airway Th2 polarization.

Research progress of tumor-associated macrophages in immune checkpoint inhibitor tolerance in colorectal cancer

The relevant mechanism of tumor-associated macrophages (TAMs) in the treatment of colorectal cancer patients with immune checkpoint inhibitors (ICIs) is discussed, and the application prospects of TAMs in reversing the treatment tolerance of ICIs are discussed to provide a reference for related studies. As a class of drugs widely used in clinical tumor immunotherapy, ICIs can act on regulatory molecules on cells that play an inhibitory role-immune checkpoints-and kill tumors in the form of an immune response by activating a variety of immune cells in the immune system. The sensitivity of patients with different types of colorectal cancer to ICI treatment varies greatly. The phenotype and function of TAMs in the colorectal cancer microenvironment are closely related to the efficacy of ICIs. ICIs can regulate the phenotypic function of TAMs, and TAMs can also affect the tolerance of colorectal cancer to ICI therapy. TAMs play an important role in ICI resistance, and making full use of this target as a therapeutic strategy is expected to improve the immunotherapy efficacy and prognosis of patients with colorectal cancer.

SPDYC serves as a prognostic biomarker related to lipid metabolism and the immune microenvironment in breast cancer

Breast cancer remains the most common malignant carcinoma among women globally and is resistant to several therapeutic agents. There is a need for novel targets to improve the prognosis of patients with breast cancer. Bioinformatics analyses were conducted to explore potentially relevant prognostic genes in breast cancer using The Cancer Genome Atlas (TCGA) and The Gene Expression Omnibus (GEO) databases. Gene subtypes were categorized by machine learning algorithms. The machine learning-related breast cancer (MLBC) score was evaluated through principal component analysis (PCA) of clinical patients' pathological statuses and subtypes. Immune cell infiltration was analyzed using the xCell and CIBERSORT algorithms. Kyoto Encyclopedia of Genes and Genomes enrichment analysis elucidated regulatory pathways related to speedy/RINGO cell cycle regulator family member C (SPDYC) in breast cancer. The biological functions and lipid metabolic status of breast cancer cell lines were validated via quantitative real-time polymerase chain reaction (RT‒qPCR) assays, western blotting, CCK-8 assays, PI‒Annexin V fluorescence staining, transwell assays, wound healing assays, and Oil Red O staining. Key differentially expressed genes (DEGs) in breast cancer from the TCGA and GEO databases were screened and utilized to establish the MLBC score. Moreover, the MLBC score we established was negatively correlated with poor prognosis in breast cancer patients. Furthermore, the impacts of SPDYC on the tumor immune microenvironment and lipid metabolism in breast cancer were revealed and validated. SPDYC is closely related to activated dendritic cells and macrophages and is simultaneously correlated with the immune checkpoints CD47, cytotoxic T lymphocyte antigen-4 (CTLA-4), and poliovirus receptor (PVR). SPDYC strongly correlated with C-C motif chemokine ligand 7 (CCL7), a chemokine that influences breast cancer patient prognosis. A significant relationship was discovered between key genes involved in lipid metabolism and SPDYC, such as ELOVL fatty acid elongase 2 (ELOVL2), malic enzyme 1 (ME1), and squalene epoxidase (SQLE). Potent inhibitors targeting SPDYC in breast cancer were also discovered, including JNK inhibitor VIII, AICAR, and JW-7-52-1. Downregulation of SPDYC expression in vitro decreased proliferation, increased the apoptotic rate, decreased migration, and reduced lipid droplets. SPDYC possibly influences the tumor immune microenvironment and regulates lipid metabolism in breast cancer. Hence, this study identified SPDYC as a pivotal biomarker for developing therapeutic strategies for breast cancer.

Deciphering the impact of aggregated autophagy-related genes TUBA1B and HSP90AA1 on colorectal cancer evolution: a single-cell sequencing study of the tumor microenvironment

BACKGROUND

Colorectal cancer (CRC) is the third most prevalent cancer worldwide, with the tumor microenvironment (TME) playing a crucial role in its progression. Aggregated autophagy (AA) has been recognized as a factor that exacerbates CRC progression. This study aims to study the relationship between aggregated autophagy and CRC using single-cell sequencing techniques. Our goal is to explain the heterogeneity of the TME and to explore the potential for targeted personalized therapies.

OBJECTIVE

To study the role of AA in CRC, we employed single-cell sequencing to discern distinct subpopulations within the TME. These subpopulations were characterized by their autophagy levels and further analyzed to identify specific biological processes and marker genes.

RESULTS

Our study revealed significant correlations between immune factors and both clinical and biological characteristics of the tumor microenvironment (TME), particularly in cells expressing TUBA1B and HSP90AA1. These immune factors were associated with T cell depletion, a reduction in protective factors, diminished efficacy of immune checkpoint blockade (ICB), and enhanced migration of cancer-associated fibroblasts (CAFs), resulting in pronounced inflammation. In vitro experiments showd that silencing TUBA1B and HSP90AA1 using siRNA (Si-TUBA1B and Si-HSP90AA1) significantly reduced the expression of IL-6, IL-7, CXCL1, and CXCL2 and inhibition of tumor cell growth in Caco-2 and Colo-205 cell lines. This reduction led to a substantial alleviation of chronic inflammation and highlighted the heterogeneous nature of the TME.

CONCLUSION

This study marks an initial foray into understanding how AA-associated processes may potentiate the TME and weaken immune function. Our findings provide insights into the complex dynamics of the TME and highlight potential targets for therapeutic intervention, suggesting a key role for AA in the advancement of colorectal cancer.

Increased PVR Expression on Bone Marrow Macrophages May Promote Resistance to TIGIT Blockade in Multiple Myeloma

PURPOSE

TIGIT blockade in our ex vivo model of bone marrow (BM) reduced the number of malignant plasma cells (PC) in only half of patients with multiple myeloma. Here, we wanted to investigate whether increased expression of TIGIT ligands may inhibit T-cell immune response promoting resistance to TIGIT blockade.

EXPERIMENTAL DESIGN

We first characterized the number and phenotype of BM macrophages in different stages of the disease by multiparameter flow cytometry. We assessed the effect of TIGIT ligands on PC survival by performing experiments in the ex vivo BM model and analyzed changes in gene expression by using NanoString technology and real-time PCR.

RESULTS

The frequency of BM macrophages was significantly decreased in multiple myeloma, which was accompanied by changes in their immunophenotype. Moreover, we found a higher number of malignant PC in ex vivo BM cells cultured onto the poliovirus receptor (PVR) and nectin-2 compared with control, suggesting that both ligands may support PC survival. In addition, the presence of PVR, but not nectin-2, overcame the therapeutic effect of TIGIT blockade or exogenous IL2. Furthermore, exogenous IL2 increased TIGIT expression on both CD4+ and CD8+ T cells and, indirectly, PVR on BM macrophages. Consistently, PVR reduced the number of cytotoxic T cells and promoted a gene signature with reduced effector molecules.

CONCLUSIONS

IL2 induced TIGIT on T cells in the BM, in which increased PVR expression resulted in cytotoxic T-cell inhibition, promoting PC survival and resistance to TIGIT blockade.

Exploring the immunometabolic potential of Danggui Buxue Decoction for the treatment of IBD-related colorectal cancer

Danggui Buxue (DGBX) decoction is a classical prescription composed of Astragali Radix (AR) and Angelicae Sinensis Radix (ASR), used to enrich blood, and nourish Qi in Chinese medicine, with the potential to recover energy and stimulate metabolism. Chronic inflammation is a risk factor in the development of inflammatory bowel disease (IBD)-related colorectal cancer (CRC). More importantly, AR and ASR have anti-inflammatory and anti-cancer activities, as well as prefiguring a potential effect on inflammation-cancer transformation. We, therefore, aimed to review the immunometabolism potential of DGBX decoction and its components in this malignant transformation, to provide a helpful complement to manage the risk of IBD-CRC. The present study investigates the multifaceted roles of DGBX decoction and its entire components AR and ASR, including anti-inflammation effects, anti-cancer properties, immune regulation, and metabolic regulation. This assessment is informed by a synthesis of scholarly literature, with more than two hundred articles retrieved from PubMed, Web of Science, and Scopus databases within the past two decades. The search strategy employed utilized keywords such as "Danggui Buxue", "Astragali Radix", "Angelicae Sinensis Radix", "Inflammation", and "Metabolism", alongside the related synonyms, with a particular emphasis on high-quality research and studies yielding significant findings. The potential of DGBX decoction in modulating immunometabolism holds promise for the treatment of IBD-related CRC. It is particularly relevant given the heterogeneity of CRC and the growing trend towards personalized medicine, but the precise and detailed mechanism necessitate further in vivo validation and extensive clinical studies to substantiate the immunometabolic modulation and delineate the pathways involved.

Recent developments in immunotherapy for gastrointestinal tract cancers

The past few decades have witnessed the rise of immunotherapy for Gastrointestinal (GI) tract cancers. The role of immune checkpoint inhibitors (ICIs), particularly programmed death protein 1 (PD-1) and PD ligand-1 antibodies, has become increasingly pivotal in the treatment of advanced and perioperative GI tract cancers. Currently, anti-PD-1 plus chemotherapy is considered as first-line regimen for unselected advanced gastric/gastroesophageal junction adenocarcinoma (G/GEJC), mismatch repair deficient (dMMR)/microsatellite instability-high (MSI-H) colorectal cancer (CRC), and advanced esophageal cancer (EC). In addition, the encouraging performance of claudin18.2-redirected chimeric antigen receptor T-cell (CAR-T) therapy in later-line GI tract cancers brings new hope for cell therapy in solid tumour treatment. Nevertheless, immunotherapy for GI tumour remains yet precise, and researchers are dedicated to further maximising and optimising the efficacy. This review summarises the important research, latest progress, and future directions of immunotherapy for GI tract cancers including EC, G/GEJC, and CRC.

Consensus clustering and development of a risk signature based on trajectory differential genes of cancer-associated fibroblast subpopulations in colorectal cancer

BACKGROUND

Cancer-associated fibroblasts (CAFs) play a crucial role in the progression of colorectal cancer (CRC). However, the impact of CAF subpopulation trajectory differentiation on CRC remains unclear.

METHODS

In this study, we first explored the trajectory differences of CAFs subpopulations using bulk and integrated single-cell sequencing data, and then performed consensus clustering of CRC samples based on the trajectory differential genes of CAFs subpopulations. Subsequently, we analyzed the heterogeneity of CRC subtypes using bioinformatics. Finally, we constructed relevant prognostic signature using machine learning and validated them using spatial transcriptomic data.

RESULTS

Based on the differential genes of CAFs subpopulation trajectory differentiation, we identified two CRC subtypes (C1 and C2) in this study. Compared to C1, C2 exhibited worse prognosis, higher immune evasion microenvironment and high CAF characteristics. C1 was primarily associated with metabolism, while C2 was primarily associated with cell metastasis and immune regulation. By combining 101 combinations of 10 machine learning algorithms, we developed a High-CAF risk signatures (HCAFRS) based on the C2 characteristic gene. HCAFRS was an independent prognostic factor for CRC and, when combined with clinical parameters, significantly predicted the overall survival of CRC patients. HCAFRS was closely associated with epithelial-mesenchymal transition, angiogenesis, and hypoxia. Furthermore, the risk score of HCAFRS was mainly derived from CAFs and was validated in the spatial transcriptomic data.

CONCLUSION

In conclusion, HCAFRS has the potential to serve as a promising prognostic indicator for CRC, improving the quality of life for CRC patients.

Pan-cancer analysis of immune checkpoint receptors and ligands in various cells in the tumor immune microenvironment

Drugs that target immune checkpoint have become the most popular weapon in cancer immunotherapy, yet only have practical benefits for a small percentage of patients. Tumor cells constantly interact with their microenvironment, which is made up of a variety of immune cells as well as endothelial cells and fibroblasts. Immune checkpoint expression and blocked signaling of immune cells in the tumor microenvironment (TME) are key to tumor progression. In this study, we perform deliberation convolution on the TCGA database for human lung, breast, and colorectal cancer to infer crosstalk between immune checkpoint receptors (ICRs) and ligands (ICLs) in TME of pan-carcinogenic solid tumor types, validated by flow cytometry. Analysis of immune checkpoints showed that there was little variation between different tumor types. It showed that CD160, LAG3, TIGIT were found to be highly expressed in CD8+ T cells instead of CD4+ T cells, PD-L1, PD-L2, CD86, LGALS9, TNFRSF14, LILRB4 and other ligands were highly expressed on macrophages, FVR, NECTIN2, FGL1 were highly expressed on Epithelial cells, CD200 was highly expressed in Endothelial cells, and CD80 was highly expressed in CD8 High expression on T cells. Overall, our study provides a new resource for the expression of immune checkpoints in TME on various types of cells. Significance: This study provides immune checkpoint expression of immune cells of multiple cancer types to infer immune mechanisms in the tumor microenvironment and provide ideas for the development of new immune checkpoint-blocking drugs.

Dissection of triple-negative breast cancer microenvironment and identification of potential therapeutic drugs using single-cell RNA sequencing analysis

Breast cancer remains a leading cause of mortality in women worldwide. Triple-negative breast cancer (TNBC) is a particularly aggressive subtype characterized by rapid progression, poor prognosis, and lack of clear therapeutic targets. In the clinic, delineation of tumor heterogeneity and development of effective drugs continue to pose considerable challenges. Within the scope of our study, high heterogeneity inherent to breast cancer was uncovered based on the landscape constructed from both tumor and healthy breast tissue samples. Notably, TNBC exhibited significant specificity regarding cell proliferation, differentiation, and disease progression. Significant associations between tumor grade, prognosis, and TNBC oncogenes were established via pseudotime trajectory analysis. Consequently, we further performed comprehensive characterization of the TNBC microenvironment. A crucial epithelial subcluster, E8, was identified as highly malignant and strongly associated with tumor cell proliferation in TNBC. Additionally, epithelial-mesenchymal transition (EMT)-associated fibroblast and M2 macrophage subclusters exerted an influence on E8 through cellular interactions, contributing to tumor growth. Characteristic genes in these three cluster cells could therefore serve as potential therapeutic targets for TNBC. The collective findings provided valuable insights that assisted in the screening of a series of therapeutic drugs, such as pelitinib. We further confirmed the anti-cancer effect of pelitinib in an orthotopic 4T1 tumor-bearing mouse model. Overall, our study sheds light on the unique characteristics of TNBC at single-cell resolution and the crucial cell types associated with tumor cell proliferation that may serve as potent tools in the development of effective anti-cancer drugs.

S100A9 Induces Macrophage M2 Polarization and Immunomodulatory Role in the Lesion Site After Spinal Cord Injury in Rats

Immune response is pivotal in the secondary injury of spinal cord injury (SCI). Polarization of macrophages (MΦ) influences the immune response in the secondary injury, which is regulated by several immune-related proteins. M2Φ plays the immunomodulatory role in the central nervous system. This study used bioinformatic analysis and machine algorithms to screen hub immune-related proteins after SCI and experimentally investigate the role of the target protein in the M2Φ polarization and immunomodulation in rats and in vitro after SCI. We downloaded GSE151371 and GSE45006, hub immune-related genes were screened using machine learning algorithms, and the expression of S100A9 was verified by datasets. Allen's weight-drop injury SCI model in Sprague-Dawley rat and bone marrow-derived rat MΦ with myelin debris model were used to study the effects of S100A9 on M2Φ polarization and immunomodulation at the lesion site and in vitro. Bioinformatic analysis showed that S100A9 acts as a hub immune-related gene in the SCI patients and rats. S100A9 increased at the lesion site in SCI rats, and its inhibition reduced CD206 and ARG-1 expression. Exogenous S100A9 promoted CD206 and ARG-1 expression in MΦ. S100A9 also increased the expression of PD-L1 and decreased MHC II at the lesion site in SCI rats and MΦ with myelin debris, and enhanced mitochondrial activity in rat MΦ with myelin debris. In conclusion, S100A9 is an indispensable factor in the immune process in secondary injury following SCI.

S100P facilitates LUAD progression via PKA/c-Jun-mediated tumor-associated macrophage recruitment and polarization

S100P, a member of the S100 calcium-binding protein family, is closely associated with abnormal proliferation, invasion, and metastasis of various cancers. However, its role in the lung adenocarcinoma (LUAD) tumor microenvironment (TME) remains unclear. In this study, we observed specific expression of S100P on tumor cells in LUAD patients through tissue immunofluorescence analysis. Furthermore, this expression was strongly correlated with the recruitment and polarization of tumor-associated macrophages (TAMs). Bioinformatics analysis revealed that high S100P expression is associated with poorer overall survival in LUAD patients. Subsequently, a subcutaneous mouse model demonstrated that S100P promotes recruitment and polarization of TAMs towards the M2 type. Finally, in vitro studies on LUAD cells revealed that S100P enhances the secretion of chemokines and polarizing factors by activating the PKA/c-Jun pathway, which is implicated in TAM recruitment and polarization towards the M2 phenotype. Moreover, inhibition of c-Jun expression impedes the ability of TAMs to infiltrate and polarize towards the M2 phenotype. In conclusion, our study demonstrates that S100P facilitates LUAD cells growth by recruiting M2 TAMs through PKA/c-Jun signaling, resulting in the production of various cytokines. Considering these findings, S100P holds promise as an important diagnostic marker and potential therapeutic target for LUAD.

CAR-T lymphocyte-based cell therapies; mechanistic substantiation, applications and biosafety enhancement with suicide genes: new opportunities to melt side effects

Immunotherapy has made significant strides in cancer treatment with strategies like checkpoint blockade antibodies and adoptive T cell transfer. Chimeric antigen receptor T cells (CAR-T) have emerged as a promising approach to combine these strategies and overcome their limitations. This review explores CAR-T cells as a living drug for cancer treatment. CAR-T cells are genetically engineered immune cells designed to target and eliminate tumor cells by recognizing specific antigens. The study involves a comprehensive literature review on CAR-T cell technology, covering structure optimization, generations, manufacturing processes, and gene therapy strategies. It examines CAR-T therapy in haematologic cancers and solid tumors, highlighting challenges and proposing a suicide gene-based mechanism to enhance safety. The results show significant advancements in CAR-T technology, particularly in structure optimization and generation. The manufacturing process has improved for broader clinical application. However, a series of inherent challenges and side effects still need to be addressed. In conclusion, CAR-T cells hold great promise for cancer treatment, but ongoing research is crucial to improve efficacy and safety for oncology patients. The proposed suicide gene-based mechanism offers a potential solution to mitigate side effects including cytokine release syndrome (the most common toxic side effect of CAR-T therapy) and the associated neurotoxicity.

Systemic delivery of oncolytic herpes virus using CAR-T cells enhances targeting of antitumor immuno-virotherapy

Recent studies have indicated that combining oncolytic viruses with CAR-T cells in therapy has shown superior anti-tumor effects, representing a promising approach. Nonetheless, the localized delivery method of intratumoral injection poses challenges for treating metastatic tumors or distal tumors that are difficult to reach. To address this obstacle, we employed HSV-1-infected CAR-T cells, which systemically delivery HSV into solid tumors. The biological function of CAR-T cells remained intact after loading them with HSV for a period of three days. In both immunocompromised and immunocompetent GBM orthotopic mouse models, B7-H3 CAR-T cells effectively delivered HSV to tumor lesions, resulting in enhanced T-cell infiltration and significantly prolonged survival in mice. We also employed a bilateral subcutaneous tumor model and observed that the group receiving intratumoral virus injection exhibited a significant reduction in tumor volume on the injected side, while the group receiving intravenous infusion of CAR-T cells carrying HSV displayed suppressed tumor growth on both sides. Hence, CAR-THSV cells offer notable advantages in the systemic delivery of HSV to distant tumors. In conclusion, our findings emphasize the potential of CAR-T cells as carriers for HSV, presenting significant advantages for oncolytic virotherapy targeting distant tumors.

Pan-Cancer Single-Cell and Spatial-Resolved Profiling Reveals the Immunosuppressive Role of APOE+ Macrophages in Immune Checkpoint Inhibitor Therapy

The heterogeneity of macrophages influences the response to immune checkpoint inhibitor (ICI) therapy. However, few studies explore the impact of APOE+ macrophages on ICI therapy using single-cell RNA sequencing (scRNA-seq) and machine learning methods. The scRNA-seq and bulk RNA-seq data are Integrated to construct an M.Sig model for predicting ICI response based on the distinct molecular signatures of macrophage and machine learning algorithms. Comprehensive single-cell analysis as well as in vivo and in vitro experiments are applied to explore the potential mechanisms of the APOE+ macrophage in affecting ICI response. The M.Sig model shows clear advantages in predicting the efficacy and prognosis of ICI therapy in pan-cancer patients. The proportion of APOE+ macrophages is higher in ICI non-responders of triple-negative breast cancer compared with responders, and the interaction and longer distance between APOE+ macrophages and CD8+ exhausted T (Tex) cells affecting ICI response is confirmed by multiplex immunohistochemistry. In a 4T1 tumor-bearing mice model, the APOE inhibitor combined with ICI treatment shows the best efficacy. The M.Sig model using real-world immunotherapy data accurately predicts the ICI response of pan-cancer, which may be associated with the interaction between APOE+ macrophages and CD8+ Tex cells.

Immunotherapy of microsatellite stable colorectal cancer: resistance mechanisms and treatment strategies

In recent years, immunotherapy strategies based on immune checkpoint inhibitors have yielded good efficacy in colorectal cancer (CRC)especially in colorectal cancer with microsatellite instability-high. However, microsatellite-stable (MSS) CRCs account for about 85% of CRCs and are resistant to immunotherapy. Previous studies have shown that compared with MSS CRC, high microsatellite instability CRC possesses a higher frequency of mutations and can generate more neoantigens. Therefore, improving the sensitivity of immunotherapy to MSS CRC is a hot topic which is crucial for the treatment of MSS CRC. This review aims to discuss the factors contributing to MSS CRC insensitivity to immunotherapy and explored potential solutions to overcome immunotherapy resistance.

Discovery of a Novel CSF-1R Inhibitor with Highly Improved Pharmacokinetic Profiles and Superior Efficacy in Colorectal Cancer Immunotherapy

Blocking CSF-1/CSF-1R pathway has emerged as a promising strategy to remodel tumor immune microenvironment (TME) by reprogramming tumor-associated macrophages (TAMs). In this work, a novel CSF-1R inhibitor C19 with a highly improved pharmacokinetic profile and in vivo anticolorectal cancer (CRC) efficiency was successfully discovered. C19 could effectively reprogram M2-like TAMs to M1 phenotype and reshape the TME by inducing the recruitment of CD8+ T cells into tumors and reducing the infiltration of immunosuppressive Tregs/MDSCs. Deeper mechanistic studies revealed that C19 facilitated the infiltration of CD8+ T cells by enhancing the secretion of chemokine CXCL9, thus significantly potentiating the anti-CRC efficiency of PD-1 blockade. More importantly, C19 combined with PD-1 mAb could induce durable antitumor immune memory, effectively overcoming the recurrence of CRC. Taken together, our findings suggest that C19 is a promising therapeutic option for sensitizing CRC to anti-PD-1 therapy.

CSF1R inhibition reprograms tumor-associated macrophages to potentiate anti-PD-1 therapy efficacy against colorectal cancer

PD-1 blockade therapy has made great breakthroughs in treatment of multiple solid tumors. However, patients with microsatellite-stable (MSS) colorectal cancer (CRC) respond poorly to anti-PD-1 immunotherapy. Although CRC patients with microstatellite instability (MSI) or microsatellite instability-high (MSI-H) can benefit from PD-1 blockade therapy, there are still some problems such as tumor recurrence. Tumor-associated macrophages (TAMs), most abundant immune components in tumor microenvironment (TME), largely limit the therapeutic efficacy of anti-PD-1 against CRC. The CSF1/CSF1R pathway plays a key role in regulating macrophage polarization, and blocking CSF1R signaling transduction may be a potential strategy to effectively reprogram macrophages and remodel TME. Here, we found that increasing expression of CSF1R in macrophages predicted poor prognosis in CRC cohort. Furthermore, we discovered a novel potent CSF1R inhibitor, PXB17, which significantly reprogramed M2 macrophages to M1 phenotype. Mechanically, PXB17 significantly blocked activation of PI3K/AKT/mTORC1 signaling, resulting in inhibition of cholesterol biosynthesis. Results from 3D co-culture system suggested that PXB17-repolarized macrophages could induce infiltration of CD8+ T lymphocytes in tumors and improve the immunosuppressive microenvironment. In vivo, PXB17 significantly halted CRC growth, with a stronger effect than PLX3397. In particular, PXB17 potently enhanced therapeutic activity of PD-1 mAb in CT-26 (MSS) model and prevented tumor recurrence in MC-38 (MSI-H) model by promoting formation of long-term memory immunity. Our study opens a new avenue for CSF1R in tumor innate and adaptive anti-tumor immunomodulatory activity and suggests that PXB17 is a promising immunotherapy molecule for enhancing the efficacy of PD-1 mAb or reducing tumor recurrence of CRC.

Antitumour mechanisms of traditional Chinese medicine elicited by regulating tumour-associated macrophages in solid tumour microenvironments

Tumour-associated macrophages (TAMs), particularly M2-TAMs, constitute the largest proportion of immune cells in the solid tumour microenvironment, playing a crucial role in tumour progression and correlating with poor prognosis. TAMs promote the proliferation, invasion, and metastasis of tumour cells by remodelling the extracellular matrix, inhibiting immunity, promoting immune escape and tumour angiogenesis, and affecting cell metabolism. Traditional Chinese medicine (TCM) has been used clinically in China for millennia. Chinese herbs exhibit potent antitumour effects with minimal to no toxicity, substantially contributing to prolonging the lives of patients with cancer and improving their quality of life. TCM has unique advantages in improving the solid tumour microenvironment, particularly in regulating TAMs to further inhibit tumour angiogenesis, reduce drug resistance, reverse immunosuppression, and enhance antitumour immunity. This review highlights the TAM-associated mechanisms within the solid tumour microenvironment, outlines the recent advancements in TCM targeting TAMs for antitumour effects, emphasises the superiority of combining TCM with standard treatments or new nano-drug delivery systems, and evaluates the safety and efficacy of TCM combined with conventional treatments via clinical trials to provide insights and strategies for future research and clinical treatment.

The prognostic value of LAYN in HPV-related head and neck squamous cell carcinoma and its influence on immune cell infiltration

BACKGROUND

HPV-positive head and neck squamous cell carcinoma (HNSCC) exhibits different characteristics from HPV-negative tumors in terms of tumor development, clinical features, treatment response, and prognosis. Layilin (LAYN), which contains homology with C-type lectins, plays a critical role in tumorigenesis and cancer progression. However, the prognostic value of LAYN and the relationship between LAYN and immune infiltration levels in HPV-related HNSCC patients still require a comprehensive understanding. Herein, we aimed to assess the prognostic value of LAYN and to investigate its underlying immunological function in HPV-related HNSCC.

METHODS

Through various bioinformatics methods, we analyzed the data from The Cancer Genome Atlas (TCGA), Tumor Immune Estimation Resource (TIMER) and Gene Expression Profiling Interactive Analysis (GEPIA) databases to explore the potential underlying oncogenic impression of LAYN, including the relevance of LAYN to survival outcomes, clinicopathological factors, immune cell infiltration, and immune marker sets in HPV-related HNSCC. The expression levels of LAYN and HPV were also verified in HNSCC patient tissues.

RESULTS

LAYN was differentially expressed in a variety of tumors. The expression of LAYN in HNSCC was significantly higher than that in adjacent normal tissues (P < 0.0001), and high expression of LAYN was correlated with poor overall survival (OS) in HNSCC patients (Hazard Ratio (HR) = 1.3, P = 0.035). Moreover, LAYN expression level in HPV-positive HNSCC patients was significantly lower than that in HPV-negative patients, with HPV-positive HNSCC patients displaying a trend of favorable prognosis. In addition, the relationship between LAYN expression and immune infiltration levels in HPV-positive HNSCC group was less tightly correlated than that in HPV-negative HNSCC group, and there was a strong relationship between LAYN expression and markers of M2 macrophage (P < 0.001) and exhausted T cells (P < 0.05) in HPV-negative HNSCC. Kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis suggested that LAYN potentially influenced tumor progression through HPV infection and other cancer-related pathways.

CONCLUSIONS

LAYN might contribute to tumorigenesis via its positive correlation with immune checkpoint molecules and tumor-associated macrophages (TAMs). Our study might provide a novel prognostic biomarker and latent therapeutic target for the treatment of HPV-related HNSCC.

Repolarizing Tumor-Associated Macrophages and inducing immunogenic cell Death: A targeted liposomal strategy to boost cancer immunotherapy

Cancer immunotherapy has shown promise in treating various malignancies. However, the presence of an immunosuppressive tumor microenvironment (TME) triggered by M2 tumor-associated macrophages (TAMs) and the limited tumor cell antigenicity have hindered its broader application. To address these challenges, we developed DOX/R837@ManL, a liposome loaded with imiquimod (R837) and doxorubicin (DOX), modified with mannose-polyethylene glycol (Man-PEG). DOX/R837@ManL employed a mannose receptor (MRC1)-mediated targeting strategy, allowing it to accumulate selectively at M2 Tumor associated macrophages (TAMs) and tumor sites. R837, an immune adjuvant, promoted the conversion of immunosuppressive M2 TAMs into immunostimulatory M1 TAMs, and reshaped the immunosuppressive TME. Simultaneously, DOX release induced immunogenic cell death (ICD) in tumor cells and enhanced tumor cell antigenicity by promoting dendritic cells (DCs) maturation. Through targeted delivery, the synergistic action of R837 and DOX activated innate immunity and coordinated adaptive immunity, enhancing immunotherapy efficacy. In vivo experiments have demonstrated that DOX/R837@ManL effectively eliminated primary tumors and lung metastases, while also preventing tumor recurrence post-surgery. These findings highlighted the potential of DOX/R837@ManL as a promising strategy for cancer immunotherapy.

A New Method for Constructing Macrophage-Associated Predictors of Treatment Efficacy Based on Single-Cell Sequencing Analysis

Tumor-associated macrophages (TAMs) are highly infiltrated in the tumor microenvironment (TME) of colorectal cancer (CRC) and play a vital role in CRC's development as well as prognosis. The required data were obtained from the Gene Expression Omnibus database and The Cancer Genome Atlas. Univariate Cox regression and least absolute shrinkage operator analyses were executed for model construction. TME assessment and immune prediction were performed using the ESTIMATE software package and the single sample genome enrichment analysis algorithm. The results show patients with low a TAMs risk score (TRS) had a better prognosis in both The Cancer Genome Atlas and Gene Expression Omnibus cohorts. Patients with low TRS were more sensitive to 3 chemotherapeutic agents: oxaliplatin, paclitaxel, and cisplatin ( P <0.05). TME assessment showed that the low TRS group had less infiltration of M2 macrophages and regulatory T cells, but CD4 + T cells, NK cells, and dendritic cells occupy a greater proportion of TME. Low TRS group patients have a low StromalScore and ImmuneScore but have high TumorPurity. The immune checkpoint TIM-3 gene HAVCR2 expression was significantly higher in the high TRS group. Finally, we created a nomogram including TRS for forecasting survival, and TRS was significantly associated with the clinical stage of the patients. In conclusion, the TRS serves as a reliable prognostic indicator of CRC; it predicts patient outcomes to immunotherapy and chemotherapy and provides genomic evidence for the subsequent development of modulated TAMs for treating CRC.

Tumor-associated macrophages in colorectal cancer metastasis: molecular insights and translational perspectives

Metastasis is the leading cause of high mortality in colorectal cancer (CRC), which is not only driven by changes occurring within the tumor cells, but is also influenced by the dynamic interaction between cancer cells and components in the tumor microenvironment (TME). Currently, the exploration of TME remodeling and its impact on CRC metastasis has attracted increasing attention owing to its potential to uncover novel therapeutic avenues. Noteworthy, emerging studies suggested that tumor-associated macrophages (TAMs) within the TME played important roles in CRC metastasis by secreting a variety of cytokines, chemokines, growth factors and proteases. Moreover, TAMs are often associated with poor prognosis and drug resistance, making them promising targets for CRC therapy. Given the prognostic and clinical value of TAMs, this review provides an updated overview on the origin, polarization and function of TAMs, and discusses the mechanisms by which TAMs promote the metastatic cascade of CRC. Potential TAM-targeting techniques for personalized theranostics of metastatic CRC are emphasized. Finally, future perspectives and challenges for translational applications of TAMs in CRC development and metastasis are proposed to help develop novel TAM-based strategies for CRC precision medicine and holistic healthcare.

Astragalus Polysaccharide Alleviates Ulcerative Colitis by Regulating the Balance of mTh17/mTreg Cells through TIGIT/CD155 Signaling

The balance between memory Th17 cells (mTh17) and memory Treg cells (mTreg) plays a key role in the pathogenesis of ulcerative colitis (UC), and TIGIT signaling is involved in the differentiation of mTh17/mTreg cells. Astragalus polysaccharide (APS) has good immunomodulatory and anti-inflammatory effects. Here, the regulatory effects and potential mechanisms of APS on mTh17/mTreg cells in UC are explored. A UC model was induced with dextran sulfate sodium (DSS) and treated simultaneously with APS (200 mg/kg/day) for 10 days. After APS treatment, the mice showed a significant increase in colonic length and a significant decrease in colonic weight, colonic weight index and colonic weight/colonic length, and more intact mucosa and lighter inflammatory cell infiltration. Notably, APS significantly down-regulated the percentages of Th17 (CD4+CCR6+), cmTh17 (CD4+CCR7+CCR6+) and emTh17 (CD4+CCR7-CCR6+) cells and significantly up-regulated the percentages of cmTreg (CD4+CCR7+Foxp3+) and emTreg (CD4+CCR7-Foxp3+) cells in the mesenteric lymph nodes of the colitis mice. Importantly, APS reversed the expression changes in the TIGIT molecule on mTh17/mTreg cells in the colitis mice with fewer CD4+CCR6+TIGIT+, CD4+CCR7-CCR6+TIGIT+ and CD4+CCR7-CCR6+TIGIT+ cells and more CD4+Foxp3+TIGIT+, CD4+CCR7-Foxp3+TIGIT+ and CD4+CCR7-Foxp3+TIGIT+ cells. Meanwhile, APS significantly inhibited the protein expression of the TIGIT ligands CD155, CD113 and CD112 and downstream proteins PI3K and AKT in the colon tissues of the colitis mice. In conclusion, APS effectively alleviated DSS-induced UC in mice by regulating the balance between mTh17/mTreg cells, which was mainly achieved through regulation of the TIGIT/CD155 signaling pathway.