Metabolic profiles of regulatory T cells and their adaptations to the tumor microenvironment: implications for antitumor immunity

Pan-cancer analysis reveals PRRT4 is a potential prognostic factor of AML

BACKGROUND

Proline-rich transmembrane protein 4 (PRRT4) has been infrequently studied, with limited literature suggesting its potential as a prognostic marker for gastric cancer. This study aims to investigate the prognostic value of the PRRT4 gene in pan-cancer.

METHODS

We acquired and analyzed data from several platforms, including The Cancer Genome Atlas (TCGA), Genotype Tissue Expression Project (GTEx), Cancer Cell Line Encyclopedia (CCLE), cBioPortal, HPA, and TIMER 2.0. In addition, we have further analyzed the data using multivariate analyzes and RT-qPCR. In vitro experiments were performed to detect the proliferation and apoptosis of AML cells before and after PRRT4 knockdown.

RESULTS

PRRT4 exhibited low expression in 10 types of cancers and high expression in 3 types, and this expression was significantly correlated with tumor stage, age, and gender across various cancer types. PRRT4, identified as a potential independent prognostic factor for overall survival (OS) in several cancers including LAML, PAAD, SKCM, STAD, THYM, and UVM, and exhibited a high frequency of mutation in UCEC. Moreover, PRRT4 was found to be correlated with DNA methylation and immune infiltration in various cancers. Ultimately, in the multivariate analysis model, PRRT4 was discerned as an independent prognostic biomarker for AML, predicated on the statistics based from our institution. After PRRT4 knockdown, the proliferation ability of THP1 cells was significantly enhanced, and the apoptosis ratio was significantly decreased.

CONCLUSION

PRRT4 may serve as a potential therapeutic target and prognostic marker for various malignancies.

The microbiota-m6A-metabolism axis: Implications for therapeutic strategies in gastrointestinal cancers

Gastrointestinal (GI) cancers remain a leading cause of cancer-related mortality worldwide, with metabolic reprogramming recognized as a central driver of tumor progression and therapeutic resistance. Among the key regulatory layers, N6-methyladenosine (m6A) RNA modification-mediated by methyltransferases (writers such as METTL3/14), RNA-binding proteins (readers like YTHDFs and IGF2BPs), and demethylases (erasers including FTO and ALKBH5), plays a pivotal role in controlling gene expression and metabolic flux in the tumor context. Concurrently, the gut microbiota profoundly influences GI tumorigenesis and immune evasion by modulating metabolite availability and remodeling the tumor microenvironment. Recent evidence has uncovered a bidirectional crosstalk between microbial metabolites and m6A methylation: microbiota-derived signals dynamically regulate m6A deposition on metabolic and immune transcripts, while m6A modifications, in turn, regulate the stability and translation of key mRNAs such as PD-L1 and FOXP3. This reciprocal interaction forms self-reinforcing epigenetic circuits that drive tumor plasticity, immune escape, and metabolic adaptation. In this review, we dissect the molecular underpinnings of the microbiota-m6A-metabolism axis in GI cancers and explore its potential to inform novel strategies in immunotherapy, metabolic intervention, and microbiome-guided precision oncology.

Spatial-Constraint Modulation of Intra/Extracellular Reactive Oxygen Species by Adaptive Hybrid Materials for Boosting Pyroptosis and Combined Immunotherapy of Breast Tumor

Pyroptosis-immunotherapy has potential for triple-negative breast cancer treatment, but its efficacy is limited by insufficient pyroptosis activation and the need for phased, balanced, and spatially controlled activation of active species during long-term treatment. To reconcile intracellular/extracellular demands in tumor ablation, a nanoparticle-hydrogel hybrid enabling spatiotemporal reactive oxygen species (ROS) modulation is engineered. An open-shell sonosensitizer with unpaired electrons in its molecular orbitals is prepared by chelating Cu2⁺ with TCPP. These sonosensitizers are undergoing bovine serum albumin mediated biomineralization to form calcium phosphate particles and are incorporated into an injectable hydrogel through Schiff base crosslinking between dopamine-functionalized oxidized hyaluronic acid and gallic acid-modified chitosan. After intratumoral injection, nanoparticles endocytosed into tumor cells undergo acidic degradation, releasing calcium ions and GSH-activatable sonosensitizers. Calcium overload synergizes with ultrasound-mediated oxidative stress to induce mitochondrial damage and pyroptosis, while adhesive hydrogels retained in the extracellular matrix control excessive secondary ROS levels to protect oxidation-sensitive entities. This dual-action mechanism enhances the overall therapeutic effect by combining immediate tumor killing with long-term immune activation. This study provides a new route to hybrid material design, addressing the conflicting demands of short-term tumor ablation and long-term immune activation, overcoming the limitations of current pyroptosis-based immunotherapies.

Pediatric gliomas immunity challenges and immunotherapy advances

Pediatric gliomas, the most frequent brain tumors in children, are characterized by heterogeneity and a unique tumor immune microenvironment. They are categorized into different subtypes, including low-grade gliomas like pilocytic astrocytomas and high-grade gliomas such as diffuse midline gliomas and diffuse intrinsic pontine gliomas, each exhibiting distinct immunological profiles. The tumor immune microenvironment in pediatric gliomas is shaped by cellular and non-cellular components, including immune cells, cytokines, and the extracellular matrix, involved in tumor progression, immune evasion, and response to therapy. While pediatric low-grade gliomas often display an immunosuppressed microenvironment, high-grade gliomas are characterized by complex immune infiltrates and intricate immunosuppressive mechanisms. The blood-brain barrier further obscures immune cell recruitment and therapeutic delivery. Despite advances in understanding adult gliomas, the immunobiology of pediatric tumors is poorly investigated, with limited data on the interactions between glioma cells and immune populations such as T and natural killer cells, as well as tumor-associated macrophages. Herein, we provide an update of the current knowledge on tumor immune microenvironment interactions in pediatric gliomas, highlighting the immunosuppressive mechanisms and emerging immunotherapeutic strategies aiming at overcoming these barriers to improve clinical outcomes for affected children.

Functional heterogeneity and clinical implications of CD4+ T cell subtypes in high-grade serous ovarian carcinoma

BACKGROUND

High-grade serous ovarian carcinoma (HGSOC) is among the most lethal gynecological malignancies, characterized by late-stage diagnosis, extensive peritoneal dissemination, and limited treatment options, resulting in poor survival outcomes. The tumor microenvironment plays a critical role in disease progression and therapy resistance, with CD4+ T cells exhibiting significant plasticity and functional heterogeneity. Regulatory T cells (Tregs) are particularly implicated in immune suppression and tumor evasion. However, the spatial distribution, functional states, and prognostic significance of CD4+ T cell subtypes in HGSOC remain poorly understood.

AIM

To characterize the functional heterogeneity and tissue-specific distributions of CD4+ T cell subtypes in HGSOC and identify biomarkers for therapy.

METHODS

We analyzed single-cell RNA sequencing (scRNA-seq) data from 42 HGSOC patients, examining samples collected from adnexal tissues and ascites. CD4+ T cells were identified and classified into subtypes using unsupervised clustering and marker gene analysis. Functional profiling was performed using pathway enrichment, differential expression analysis, and functional signature scoring. Kaplan-Meier survival and Cox proportional hazards modeling were conducted to evaluate the prognostic value of CD4+ T cell subtypes.

RESULTS

Distinct distributions of CD4+ T cell subtypes were identified between adnexal tissues and ascites. Naive CD4+ T cells were predominant in ascites, while Tregs and CXCL13-expressing CD4+ T cells were enriched in adnexal tissues. Tregs were further categorized into four subtypes (Treg1, Treg2, Treg3, and TISG), each exhibiting unique molecular signatures and tissue-specific adaptations. Treg3 cells, enriched in adnexal tissues, were characterized by high levels of activation and exhaustion markers, correlating with poor clinical outcomes in HGSOC patients.

CONCLUSION

Treg3 cells drive immune suppression and tumor progression in HGSOC, making them a key immunotherapy target. Their adnexal enrichment highlights the need for tissue-specific immune profiling in precision treatment.

APOL6 as a potential biomarker of immuno-correlation and therapeutic prediction in cancer immunotherapy

The emergence of immune checkpoint inhibitors (ICIs) has significantly revolutionized the approach to treating advanced cancers. Despite their remarkable efficacy, not all patients exhibit favorable responses to ICI therapy. Hence, more biomarkers for therapeutic prediction need to be discovered. In this study, we utilized public cohorts to investigate the predictive significance and immunological associations of apolipoprotein L6 (APOL6) in cancers. The expression of APOL6 was found to be enhanced in tumors of patients who exhibited strong immunotherapeutic responses across various types of cancer. Furthermore, APOL6 showed immune correlations in pan-cancer and was confirmed by the tissue microarray cohort and in vitro experiments. Overall, this study highlights that APOL6 serves as a beneficial biomarker for immune checkpoint inhibitors in patients with cancer. Additional research involving larger numbers of patients and the underlying mechanism is necessary to determine its effectiveness as a biomarker for predicting the benefits of ICIs.

Harnessing monocyte dynamics for treatment of multiple sclerosis; insights from experimental model studies

Monocytes are central to the innate immune system's response to infection or injury. In murine, these cells are classified into distinct subsets: classical monocytes, defined by elevated Ly6C expression (Ly6Chi), intermediate monocytes (Ly6Cint), and non-classical inflammatory monocytes, characterized by low Ly6C expression (Ly6Clow). Monocytes recruited to tissues differentiate into macrophages, which can be pro-inflammatory or anti-inflammatory, thereby influencing disease processes and outcomes. The principal function of classical monocytes is the mediation of pro-inflammatory reactions, whereas non-classical monocytes are associated with repair and anti-inflammatory processes, patrolling the lumen of the vessels. Growing evidence highlights the importance of monocytes in multiple sclerosis (MS), an autoimmune and neurodegenerative disease of the central nervous system (CNS). Recent studies indicate that modulation of the innate immune system, focusing specifically on the shift from Ly6Chi to Ly6Clow monocytes, is an effective therapeutic strategy for neurodegenerative diseases, such as Alzheimer's and MS. This transition is crucial for switching the immune response from inflammation to tissue repair and inflammation resolution, emphasizing the plasticity of monocytes and their potential as targets in MS. This review differs from prior studies in that it focuses solely on animal models of MS, which either directly perturb or study monocytes, or where therapeutic approaches mediate their protective effects through monocytes. Such details permit a subtle comprehension of monocyte dynamics in the context of MS.

Post-transcriptional regulator HuR promotes immune evasion in pancreatic ductal adenocarcinoma

The tumor microenvironment (TME) of pancreatic ductal adenocarcinoma (PDAC) is characterized by a limited infiltration of tumor-specific T cells and anti-tumor T cell activity. Extracellular factors in the PDAC TME have been widely reported to mediate immune suppression, but the contribution from tumor-intrinsic factors is not well understood. The RNA-binding protein, HuR (ELAVL1), is enriched in PDAC and negatively correlates with T cell infiltration. In an immunocompetent Kras-p53-Cre (KPC) orthotopic model of PDAC, we found that genetic disruption of HuR impaired tumor growth due to a novel role of HuR inducing T-cell suppression. Importantly, we found that HuR depletion in tumors enhanced both T cell number and activation states and diminished myeloid phenotypes by comprehensive spatial profiling of the PDAC TME. Mechanistically, HuR mediated the stabilization of mTOR pathway transcripts, and inhibition of mTOR activity rescued the impaired function of local T cells. Translating these findings, we demonstrated that HuR depletion sensitized PDAC tumors to immune checkpoint blockade, while isogenic, wildtype tumors are resistant. For the first time, we show that HuR facilitates tumor immune suppression in PDAC by inhibiting T cell infiltration and function and implicate targeting HuR as a potential therapeutic strategy in combination with immunotherapy.

Paeoniflorin Directly Targets ENO1 to Inhibit M1 Polarization of Microglia/Macrophages and Ameliorates EAE Disease

The chronic autoimmune disease multiple sclerosis (MS) now remains incurable. Paeoniflorin (PF), which is a monoterpene glucoside obtained from Paeonia lactiflora Pall, is recognized for neuroprotective and anti-inflammatory properties. However, the precise mechanism by which PF regulates MS is unclear. This work aims to elucidate the underlying mechanisms of PF in EAE, a well established animal model of MS, and to discover the target proteins that PF directly acts on. Our results revealed that PF administration can significantly attenuate the clinical symptoms of EAE and alleviate the central nervous system (CNS) inflammatory environment by inhibiting M1-type microglia/macrophages. Mechanistically, PF was found to directly interact with the glycolytic enzyme α-enolase (ENO1), inhibiting its enzymatic activity and expression to impair glucose metabolism, thereby suppressing microglia/macrophage M1 polarization and ameliorating CNS inflammation. Significantly, Eno1 knockdown in microglia/macrophages diminished their pro-inflammatory phenotype, while treatment with ENOBlock or the specific knockout of Eno1 in microglia led to EAE remission, underscoring the critical role of ENO1 in EAE progression. This study uncovers the molecular mechanism of PF in treating EAE, linking the anti-inflammatory property of PF to the glucose metabolism process, which will broaden the prospective applications of PF.

Potential role of CFLAR in enhancing 5-FU sensitivity and modulating immune cell infiltration in breast cancer

BACKGROUND

Breast cancer (BRCA), the most common malignancy among women, is a highly heterogeneous disease. Chemoresistance is a major factor leading to treatment failure in BRCA. However, mechanisms underlying the development of chemoresistance remain unclear.

METHODS

In this study, we performed a comprehensive bioinformatic analysis to examine the role of cell death-associated genes in BRCA treatment. Specifically, we focused on caspase 8 and Fas-associated protein with death domain-like apoptosis regulator (CFLAR), which was identified as a co-differentially expressed cell death-associated molecule with potential prognostic values. We then validated these findings through in vitro experiments in BT- 549 and MDA-MB- 231 breast cancer cells.

RESULTS

Based on bioinformatics analysis, CFLAR expression was found to be downregulated in patients with BRCA, whereas its high expression was significantly associated with improved prognosis. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis indicated that aberrantly expressed CFLAR was potentially associated with oxidative phosphorylation, T cell receptor signaling, and NADH dehydrogenase (ubiquinone) activity. In vitro experiments demonstrated that overexpression of CFLAR inhibited the generation of reactive oxygen species (ROS), consequently promoting 5-fluorouracil (5-FU) sensitivity in BT- 549 and MDA-MB- 231 breast cancer cells. The expression of CFLAR was positively correlated with the abundance of several tumor-infiltrating immune cells, especially CD8 + T cells, further supporting the role of CFLAR in immune regulation.

CONCLUSION

In conclusion, this study reveals the novel roles of CFLAR in enhancing chemotherapy sensitivity and patient outcome in BRCA and underscores its potential as a therapeutic target. These results supported CFLAR as a therapeutic target and prognostic biomarker in BRCA patients.

Metformin as an immunomodulatory agent in enhancing head and neck squamous cell carcinoma therapies

Head and neck squamous cell carcinoma (HNSCC) remains a significant clinical challenge due to its aggressive behavior and poor prognosis, making the development of novel therapeutics with enhanced efficacy and minimal side effects critical. Metformin, a widely used antidiabetic agent, has recently emerged as a potential adjunctive therapy for HNSCC, exhibiting both direct anti-tumor and immunomodulatory effects. This review comprehensively explores the multifaceted role of metformin in shaping the tumor immune microenvironment within HNSCC. We emphasize its pivotal role in modulating immune cell populations and its potential for synergistic action with immunotherapeutic strategies. Furthermore, we address the current challenges associated with optimizing dosing regimens, identifying predictive biomarkers, and integrating metformin with immunotherapy. By dissecting these aspects, this review aims to pave the way for the development of personalized HNSCC treatment strategies that fully exploit the therapeutic potential of metformin.

Targeting lipid metabolism in regulatory T cells for enhancing cancer immunotherapy

As immunosuppressive cells, Regulatory T cells (Tregs) exert their influence on tumor immune escape within the tumor microenvironment (TME) by effectively suppressing the activity of other immune cells, thereby significantly impeding the anti-tumor immune response. In recent years, the metabolic characteristics of Tregs have become a focus of research, especially the important role of lipid metabolism in maintaining the function of Tregs. Consequently, targeted interventions aimed at modulating lipid metabolism in Tregs have been recognized as an innovative and promising approach to enhance the effectiveness of tumor immunotherapy. This review presents a comprehensive overview of the pivotal role of lipid metabolism in regulating the function of Tregs, with a specific focus on targeting Tregs lipid metabolism as an innovative approach to augment anti-tumor immune responses. Furthermore, we discuss potential opportunities and challenges associated with this strategy, aiming to provide novel insights for enhancing the efficacy of cancer immunotherapy.

Extracellular Vesicle-Based Antitumor Nanomedicines

Extracellular vesicles (EVs) have emerged as promising bioactive carriers for delivering therapeutic agents, including nucleic acids, proteins, and small-molecule drugs, owing to their excellent physicochemical stability and biocompatibility. However, comprehensive reviews on the various types of EV-based nanomedicines for cancer therapy remain scarce. This review explores the potential of EVs as antitumor nanomedicines. Methods for EV extraction, drug loading, and engineering modifications are systematically examined, and the strengths and limitations of these technical approaches are critically assessed. Additionally, key strategies for developing EV-based antitumor therapies are highlighted. Finally, the opportunities and challenges associated with advancing EVs toward clinical translation are discussed. With the integration of multiple disciplines, robust EV-based therapeutic platforms are expected to be manufactured to provide more personalized and effective solutions for oncology patients.

Systemic lupus erythematosus: updated insights on the pathogenesis, diagnosis, prevention and therapeutics

Systemic lupus erythematosus (SLE) is a chronic inflammatory illness with heterogeneous clinical manifestations covering multiple organs. Diversified types of medications have been shown effective for alleviating SLE syndromes, ranging from cytokines, antibodies, hormones, molecular inhibitors or antagonists, to cell transfusion. Drugs developed for treating other diseases may benefit SLE patients, and agents established as SLE therapeutics may be SLE-inductive. Complexities regarding SLE therapeutics render it essential and urgent to identify the mechanisms-of-action and pivotal signaling axis driving SLE pathogenesis, and to establish innovative SLE-targeting approaches with desirable therapeutic outcome and safety. After introducing the research history of SLE and its epidemiology, we categorized primary determinants driving SLE pathogenesis by their mechanisms; combed through current knowledge on SLE diagnosis and grouped them by disease onset, activity and comorbidity; introduced the genetic, epigenetic, hormonal and environmental factors predisposing SLE; and comprehensively categorized preventive strategies and available SLE therapeutics according to their functioning mechanisms. In summary, we proposed three mechanisms with determinant roles on SLE initiation and progression, i.e., attenuating the immune system, restoring the cytokine microenvironment homeostasis, and rescuing the impaired debris clearance machinery; and provided updated insights on current understandings of SLE regarding its pathogenesis, diagnosis, prevention and therapeutics, which may open an innovative avenue in the fields of SLE management.

Bridging epigenomics and tumor immunometabolism: molecular mechanisms and therapeutic implications

Epigenomic modifications-such as DNA methylation, histone acetylation, and histone methylation-and their implications in tumorigenesis, progression, and treatment have emerged as a pivotal field in cancer research. Tumors undergo metabolic reprogramming to sustain proliferation and metastasis in nutrient-deficient conditions, while suppressing anti-tumor immunity in the tumor microenvironment (TME). Concurrently, immune cells within the immunosuppressive TME undergo metabolic adaptations, leading to alterations in their immune function. The complicated interplay between metabolites and epigenomic modulation has spotlighted the significance of epigenomic regulation in tumor immunometabolism. In this review, characteristics of the epigenomic modification associated with tumors are systematically summarized alongside with their regulatory roles in tumor metabolic reprogramming and immunometabolism. Classical and emerging approaches are delineated to broaden the boundaries of research on the crosstalk research on the crosstalk between tumor immunometabolism and epigenomics. Furthermore, we discuss potential therapeutic strategies that target tumor immunometabolism to modulate epigenomic modifications, highlighting the burgeoning synergy between metabolic therapies and immunotherapy as a promising avenue for cancer treatment.

Selective Depletion of CCR8+Treg Cells Enhances the Antitumor Immunity of Cytotoxic T Cells in Lung Cancer by Dendritic Cells

INTRODUCTION

Accumulation of regulatory T (Treg) cells, an immunosuppressive population, limits the efficacy of immunotherapy in NSCLC. C-C motif chemokine receptor 8 (CCR8) is selectively expressed in tumor-infiltrating Treg cells and is, therefore, considered an ideal target.

METHODS

The efficacy and safety of anti-CCR8 monotherapy and its combination with programmed cell death protein-1 (PD1) inhibitor were evaluated in four NSCLC-bearing mice models. To track the dynamic changes in tumor microenvironment, we performed the single-cell RNA sequencing, the single-cell T-cell receptor sequencing analysis, the flow cytometry, the multi-color immunofluorescence, and the Luminex assay on tumors after three, seven, 14, and 21 days of different treatment regimens. Then, in vitro and in vivo experiments were applied to validate our findings and explore molecular mechanisms of the synergistic effects.

RESULTS

Across four NSCLC-bearing mice models, the combination of CCR8 antibody and PD1 inhibitor significantly reduced tumor growth (p < 0.05) without obvious mouse body weight drops and systemic cytokine storm. The anti-CCR8 therapy synergizes with PD1 blockade by remodeling the tumor microenvironment and disrupting CCR8+Treg-C-C motif chemokine ligand 5 (CCL5)+ dendritic cells (DC) interaction. Mechanistically, therapeutic depletion of CCR8+Treg cells combined with PD1 inhibitor extremely increased interleukin-12 secretion by the Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway activation on CCL5+ DCs, thereby promoting cytotoxic activity of CD8+ T cells. The therapeutic potential of the CCR8 antibody LM-108 in combination with immunotherapy was observed in clinical patients with advanced NSCLC.

CONCLUSION

Overall, CCR8 expression on tumor-infiltrating Treg cells is correlated with immunosuppressive function on DCs and CD8+ T cells, thus impeding antitumor immunity.

Blocking WNT7A Enhances MHC-I Antigen Presentation and Enhances the Effectiveness of Immune Checkpoint Blockade Therapy

The limited infiltration of CD8+ T cells in tumors hampers the effectiveness of T cell-based immunotherapy, yet the mechanisms that limit tumor infiltration by CD8+ T cells remain unclear. Through bulk RNA sequencing of human tumors, we identified a strong correlation between WNT7A expression and reduced CD8+ T-cell infiltration. Further investigation demonstrated that inhibiting WNT7A substantially enhanced MHC-I expression on tumor cells. Mechanistically, WNT7A inhibition inactivated the Wnt/β-catenin signaling pathway and thus resulted in reduced physical interaction between β-catenin and p65 in the cytoplasm, which increased the nuclear translocation of p65 and activated the NF-κB pathway, ultimately promoting the transcription of genes encoding MHC-I molecules. We found that our lead compound, 1365-0109, disrupted the protein-protein interaction between WNT7A and its receptor FZD5, resulting in the upregulation of MHC-I expression. In murine tumor models, both genetic and pharmaceutical suppression of WNT7A led to increased MHC-I levels on tumor cells, and consequently enhanced the infiltration and functionality of CD8+ T cells, which bolstered antitumor immunity and improved the effectiveness of immune checkpoint blockade therapy. These findings have elucidated the intrinsic mechanisms of WNT7A-induced immune suppression, suggesting that therapeutic interventions targeting WNT7A hold promise for enhancing the efficacy of immunotherapy.

A Copper-Manganese Based Nanocomposite Induces Cuproptosis and Potentiates Anti-Tumor Immune Responses

Cancer is one of the most important challenges worldwide with an increasing incidence. However, most of patients with malignant cancer receiving traditional therapies have tumor recurrence and short-term 5-year survival. Herein, a novel Cu2O-MnO@PEG (CMP) nanomaterial is developed to treat tumors. CMP directly mediates cuproptosis in tumor cells. Meanwhile, CMP potentiates anti-tumor immune responses in the tumor microenvironment (TME) to induce tumor regression. CMP improves the tumor antigen processing and presentation of dendritic cells and tumor-associated macrophages, and further promotes CD8+ T cell responses, especially for cytotoxic CD8+ T cells and transitory exhausted CD8+ T cells. Additionally, CMP downregulates the proportion of Treg cells and CTLA-4 expression on Treg cells. Notably, CMP induces systemic immune responses against distant tumors and long-term immune memory. Furthermore, CMP synergized with PD-L1 mAb promotes tumor inhibition and sustains the anti-tumor efficacy post PD-L1 mAb treatment. Collectively, this strategy has the clinically therapeutic potential for tumors by facilitating cuproptosis in tumor cells and anti-tumor immune responses.

Multi-omics analysis identifies UBA family as potential pan-cancer biomarkers for tumor prognosis and immune microenvironment infiltration

Background

UBA1 and UBA6 are classic ubiquitin-activating E1 enzymes, which participate in the ubiquitination degradation of intracellular proteins and are closely related to the occurrence and development of various diseases and tumors. However, at present, comprehensive analysis has not been used to study the role of UBA family in cancers.

Methods

We extracted the relevant data of cancer patients from the TCGA database and studied the relationship between the expression patterns of UBA family and the survival rate, and stage of patients in pan-cancer, especially breast cancer (BRCA), colorectal cancer (COAD), renal cancer (KIRC) and lung adenocarcinoma (LUAD). In addition, we also evaluated their impact on immune infiltration using TISIDB database and R packages.

Results

UBA1 and UBA6 are highly expressed in most cancer types, which may be associated with poor prognosis of patients. This study also investigated their expression had a closely tie with clinical stages in some specific tumors. Furthermore, this study also demonstrated that these genes were closely related to immune score, immune subtypes and tumor infiltrating immune cells.

Conclusions

Our study demonstrated that the differential expression of the UBA family, along with their associated survival landscape and immune infiltration across various cancer types, holds potential as biomarkers linked to cancer immune infiltration. This finding offers a novel perspective for informing the direction of cancer treatment strategies.

Sex-related changes in lactate dehydrogenase A expression differently impact the immune response in melanoma

Melanoma is more aggressive in male patients than female ones and this is associated with sexual dimorphism in immune responses. Taking into consideration the impact tumour metabolic alterations in affecting the immune landscape, we aimed to investigate the effect of the sex-dependent metabolic profile of melanoma in re-shaping immune composition. Melanoma is characterised by Warburg metabolism, and secreted lactate has emerged as a key driver in the establishment of an immunosuppressive environment. Here, we identified lactate dehydrogenase A (LDH-A) as a crucial player in modulating sex-related differences in melanoma immune responses, both in vitro and in patient-derived specimens. LDH-A is associated with higher lactate secretion in male melanoma cells, which leads to a significant enrichment in pro-tumoural regulatory T cells (Treg) with a concurrent decrease in the number and activity of anti-tumour CD8+ T cells. Remarkably, pharmacological and genetic impairment of LDH-A in male melanoma cells normalises Treg and CD8+ infiltration. In keeping with this, in vivo pharmacological targeting of LDH-A in melanoma-bearing male mice impairs tumour growth and lung colonisation, with a concomitant modulation of Treg and CD8+ T cells infiltration. Taken together, our findings highlight the sex-related differences promoted by LDH-A in immune reshaping in melanoma, and suggest that therapeutic targeting of LDH-A could be leveraged as an effective strategy to abolish the sex-gap in melanoma progression.

Fluoride-Mediated Immune Damage Through Cytokine Network Regulation of Tregs

Long-term fluoride exposure can induce inflammatory responses in various tissues of the body, thereby affecting the inflammatory microenvironment. To explore how fluoride induces changes in immune function within this microenvironment, this study collected baseline information and biological samples from participants in areas with the drinking water type of fluorosis, and simultaneously established Wistar rat models with a 12-week and 24-week fluoride exposure, as well as a 12-week fluoride exposure followed by 12-week pure water feeding regimen. Luminex multiplex assays and enzyme-linked immunosorbent assays (ELISAs) were used to measure cytokine expression levels. Subsequently, correlation analysis, multiple linear regression, and mediation analysis were employed to explore the long-term effects induced by the complex cytokine network during fluoride exposure. The population survey results indicated that fluoride suppressed the expression of pro-inflammatory factors such as Interleukin-2 (IL-2), Interleukin-12 (IL-12), Interferon-γ (IFN-γ), Tumor necrosis factor-α (TNF-α), and anti-inflammatory factors such as Interleukin-4 (IL-4), Interleukin-13 (IL-13), and Interleukin-37 (IL-37), while promoting an increase in the proportion of regulatory T cells (Tregs) in peripheral blood. Among these, IL-2 and IFN-γ mediated the fluoride-induced peripheral Tregs expansion. Animal experiments indicate that the proportion of Tregs in peripheral blood and immune organs increases in a time-dependent manner with fluoride exposure. After reducing the fluoride concentration in the drinking water of rats, the number of Tregs remained significantly elevated. The changes in Treg numbers in the 12-week fluoride feeding group, 24-week fluoride feeding group, and 12-week fluoride feeding followed by 12-week water improvement group were related to the cytokine levels. Therefore, the impact of fluoride on the immune homeostasis has cumulative and long-term effects, and may be related to the accumulation and migration of Tregs induced by fluoride in an inflammatory environment, mediated by cytokines.

Global Trends in Research of Amino Acid Metabolism in T Lymphocytes in Recent 15 Years: A Bibliometric Analysis

Amino acid metabolism in T cells determines the therapeutic efficacy of T-cell-targeting drugs. To assess the direction of amino acid metabolism in T cells and construct related knowledge structure, we performed a bibliometric analysis aiming at amino acid metabolism in T cells utilizing studies publicized in recent 15 years. Three hundred thirty-seven related studies were downloaded from the Web of Science Core Collection (WoSCC), and the information on countries, institutes, and authors was collected and analyzed. In addition, the present research status and future trends were explored according to the results yielded from the analysis of cited references and keywords. This study revealed that publications regarding amino acid metabolism in T cells gradually increased each year. The USA is the top producer and most influential country in this field. Recent research has focused on the correlation between the metabolism of several amino acids and regulatory T cells (Tregs) and CD8+ T cells. Overall, this research offers a comprehensive exhibition on the field of amino acid metabolism in T cells, which will help researchers to study this domain more effectively and intuitively.

Integrating single-cell RNA-seq and bulk RNA-seq to explore prognostic value and immune landscapes of methionine metabolism-related signature in breast cancer

Background

Neoadjuvant, endocrine, and targeted therapies have significantly improved the prognosis of breast cancer (BC). However, due to the high heterogeneity of cancer, some patients cannot benefit from existing treatments. Increasing evidence suggests that amino acids and their metabolites can alter the tumor malignant behavior through reshaping tumor microenvironment and regulation of immune cell function. Breast cancer cell lines have been identified as methionine-dependent, and methionine restriction has been proposed as a potential cancer treatment strategy.

Methods

We integrated transcriptomic and single-cell RNA sequencing (ScRNA-seq) analyses based on The Cancer Genome Atlas (TCGA) database and Gene Expression Omnibus (GEO) datasets. Then we applied weighted gene co-expression network analysis (WGCNA) and Cox regression to evaluate methionine metabolism-related genes (MRGs) in BC, constructing and validating a prognostic model for BC patients. Immune landscapes and immunotherapy were further explored. Finally, in vitro experiments were conducted to assess the expression and function of key genes APOC1.

Results

In this study, we established and validated a prognostic signature based on eight methionine-related genes to predict overall survival (OS) in BC patients. Patients were further stratified into high-risk and low-risk groups according to prognostic risk score. Further analysis revealed significant differences between two groups in terms of pathway alterations, immune microenvironment characteristics, and immune checkpoint expression. Our study shed light on the relationship between methionine metabolism and immune infiltration in BC. APOC1, a key gene in the prognostic signature, was found to be upregulated in BC and closely associated with immune cell infiltration. Notably, APOC1 was primarily expressed in macrophages. Subsequent in vitro experiments demonstrated that silencing APOC1 reduced the generation of tumor-associated macrophages (TAMs) with an M2 phenotype while significantly decreasing the proliferation, invasion, and migration of MDA-MB-231 and MDA-MB-468 breast cancer cell lines.

Conclusion

We established a prognostic risk score consisting of genes associated with methionine metabolism, which helps predict prognosis and response to treatment in BC. The function of APOC1 in regulating macrophage polarization was explored.

Tumor metabolic regulators: key drivers of metabolic reprogramming and the promising targets in cancer therapy

Metabolic reprogramming within the tumor microenvironment (TME) is a hallmark of cancer and a crucial determinant of tumor progression. Research indicates that various metabolic regulators form a metabolic network in the TME and interact with immune cells, coordinating the tumor immune response. Metabolic dysregulation creates an immunosuppressive TME, impairing the antitumor immune response. In this review, we discuss how metabolic regulators affect the tumor cell and the crosstalk of TME. We also summarize recent clinical trials involving metabolic regulators and the challenges of metabolism-based tumor therapies in clinical translation. In a word, our review distills key regulatory factors and their mechanisms of action from the complex reprogramming of tumor metabolism, identified as tumor metabolic regulators. These regulators provide a theoretical basis and research direction for the development of new strategies and targets in cancer therapy based on tumor metabolic reprogramming.

Tumor microenvironment targeted nano-drug delivery systems for multidrug resistant tumor therapy

In recent years, nano-drug delivery systems (Nano-DDS) that target the tumor microenvironment (TME) to overcome multidrug resistance (MDR) have become a research hotspot in the field of cancer therapy. By precisely targeting the TME and regulating its unique pathological features, such as hypoxia, weakly acidic pH, and abnormally expressed proteins, etc., these Nano-DDS enable effective delivery of therapeutic agents and reversal of MDR. This scientific research community is increasing its investment in the development of diversified systems and exploring their anti-drug resistance potential. Therefore, it is particularly important to conduct a comprehensive review of the research progress of TME-targeted Nano-DDS in recent years. After a brief introduction of TME and tumor MDR, the design principle and structure of liposomes, polymer micelles and inorganic nanocarriers are focused on, and their characteristics as TME-targeted nanocarriers are described. It also demonstrates how these systems break through the cancer MDR treatment through various targeting mechanisms, discusses their synthetic innovation, research results and resistance overcoming mechanisms. The review was concluded with deliberations on the key challenges and future outlooks of targeting TME Nano-DDS in cancer therapy.

A Novel KIF4A-related Model for Predicting Immunotherapy Response and Prognosis in Kidney Renal Clear Cell Carcinoma

BACKGROUND

The efficacy of chemotherapy in treating Kidney Renal Clear Cell Carcinoma (KIRC) is limited, whereas immunotherapy has shown some promising clinical outcomes. In this context, KIF4A is considered a potential therapeutic target for various cancers. Therefore, identifying the mechanism of KIF4A that can predict the prognosis and immunotherapy response of KIRC would be of significant importance.

METHODS

Based on the TCGA Pan-Cancer dataset, the prognostic significance of the KIF4A expression across 33 cancer types was analyzed by univariate Cox algorithm. Furthermore, overlapping differentially expressed genes (DEGs1) between the KIF4A high- and lowexpression groups and DEGs2 between the KIRC and normal groups were also analyzed. Machine learning and Cox regression algorithms were performed to obtain biomarkers and construct a prognostic model. Finally, the role of KIF4A in KIRC was analyzed using quantitative real-time PCR, transwell assay, and EdU experiment.

RESULTS

Our analysis revealed that KIF4A was significant for the prognosis of 13 cancer types. The highest correlation with KIF4A was found for KICH among the tumour mutation burden (TMB) indicators. Subsequently, a prognostic model developed with UBE2C, OTX1, PPP2R2C, and RFLNA was obtained and verified with the Renal Cell Cancer-EU/FR dataset. There was a positive correlation between risk score and immunotherapy. Furthermore, the experiment results indicated that KIF4A expression was considerably increased in the KIRC group. Besides, the proliferation, migration, and invasion abilities of KIRC tumor cells were significantly weakened after KIF4A was knocked out.

CONCLUSION

We identified four KIF4A-related biomarkers that hold potential for prognostic assessment in KIRC. Specifically, early implementation of immunotherapy targeting these biomarkers may yield improved outcomes for patients with KIRC.

The 7-Methylguanosine (m7G) methylation METTL1 acts as a potential biomarker of clear cell renal cell carcinoma progression

BACKGROUND

Clear cell renal cell carcinoma (ccRCC) is the most common subtype of renal cancer. 7-Methylguanosine (m7G), one of the most prevalent RNA modifications, has been reported to play an important role in ccRCC progression; however, the specific regulators of m7G modification that are involved in this function remain unclear. This study aimed to explore the correlation between regulators of m7G methylation and ccRCC progression using unsupervised machine learning methods.

METHODS

Transcriptome and clinical data of ccRCC were retrieved from The Cancer Genome Atlas (TCGA) database to identify differentially expressed m7G-related genes associated with the overall survival of patients with ccRCC. To construct and validate a prognostic risk model, TCGA dataset samples were divided into training and test sets. A multiple-gene risk signature was constructed using least absolute shrinkage and selection operator Cox regression analysis, and its prognostic significance was assessed using Cox regression and survival analyses. Finally, immunohistochemistry was performed to verify the prognostic significance of this signature.

RESULTS

In total, 537 patients with ccRCC were included in this study. We found that 26 m7G RNA methylation regulators that were significantly differentially expressed. Univariate and multifactorial Cox regression analyses revealed that METTL1 expression was associated with ccRCC progression.

CONCLUSIONS

METTL1 associated with m7G may serve as a potential biomarker for ccRCC prognosis and diagnosis. Moreover, it may affect the prognosis of ccRCC by regulating the tumor immune microenvironment, providing a potential therapeutic target for immunotherapy. These results provide a new perspective on the role of M7G-related RNAs in ccRCC pathogenesis.

Lactylation-driven TNFR2 expression in regulatory T cells promotes the progression of malignant pleural effusion

BACKGROUND

Although tumor necrosis factor receptor 2 (TNFR2) has been recognized as an attractive next-generation candidate target for cancer immunotherapy, the factors that regulate the gene expression and their mechanistic effects on tumor-infiltrating regulatory T cells (Treg cells) remain poorly understood.

METHODS

Single-cell RNA sequencing analysis was employed to analyze the phenotypic and functional differences between TNFR2+ Treg cells and TNFR2- Treg cells. Malignant pleural effusion (MPE) from humans and mouse was used to investigate the potential mechanisms by which lactate regulates TNFR2 expression.

RESULTS

Treg cells with high TNFR2 expression exhibited elevated levels of immune checkpoint molecules. Additionally, the high expression of TNFR2 on Treg cells was positively correlated with a poor prognosis in MPE patients. Moreover, we revealed that lactate upregulated TNFR2 expression on Treg cells, thereby enhancing their immunosuppressive function in MPE. Mechanistically, lactate modulated the gene transcription of transcription factor nuclear factor-κB p65 (NF-κB p65) through histone H3K18 lactylation (H3K18la), subsequently upregulating the gene expression of TNFR2 and expediting the progression of MPE. Notably, lactate metabolism blockade combined with immune checkpoint blockade (ICB) therapy effectively enhanced the efficacy of ICB therapy, prolonged the survival time of MPE mice, and improved immunosuppression in the microenvironment of MPE.

CONCLUSIONS

The study explains the mechanism that regulates TNFR2 expression on Treg cells and its function in MPE progression, providing novel insights into the epigenetic regulation of tumor development and metabolic strategies for MPE treatment by targeting lactate metabolism in Treg cells.

OSU-T315 overcomes immunosuppression in triple-negative breast cancer by targeting the ILK/NF-κB signaling pathway to enhance immunotherapeutic efficacy

Triple negative breast cancer (TNBC) is an aggressive and immunogenic subtype of breast cancer. The absence of biomarker has given immune checkpoint inhibitors (ICIs) a broad prospect in this type of breast cancer. The infiltration of regulatory T cells (Tregs) expressing transcription factor forkhead box P3 (Foxp3) in the tumor microenvironment (TME) is the key factor leading to ICIs resistance. Therefore, elimination of tumor antigen-specific Tregs may be an important aspect of improving ICIs efficacy. In this study, it based on the Gene Expression Omnibus and The Cancer Genome Atlas database, along with in vivo and in vitro experimental models, to verified that the high expression of integrin-linked kinase (ILK) in TNBC is the key differential factor leading to the high infiltration of Foxp3+-Tregs in the TME. Then, we selected ILK-specific inhibitor, OSU-T315, to intervene in vitro and vivo. Importantly, we found that OSU-T315 blocked the secretion of CCL17/CCL22 in tumor cells by inhibiting the ILK/NF-κB pathway, resulting in the apoptosis of Foxp3+-Tregs and decreased programmed cell death-1 (PD-1) expression. Therefore, our findings indicate a novel mechanism of OSU-T315 with potential therapeutic application in TNBC.

Metabolic targeting of regulatory T cells in oral squamous cell carcinoma: new horizons in immunotherapy

Oral squamous cell carcinoma (OSCC) is a prevalent oral malignancy, which poses significant health risks with a high mortality rate. Regulatory T cells (Tregs), characterized by their immunosuppressive capabilities, are intricately linked to OSCC progression and patient outcomes. The metabolic reprogramming of Tregs within the OSCC tumor microenvironment (TME) underpins their function, with key pathways such as the tryptophan-kynurenine-aryl hydrocarbon receptor, PI3K-Akt-mTOR and nucleotide metabolism significantly contributing to their suppressive activities. Targeting these metabolic pathways offers a novel therapeutic approach to reduce Treg-mediated immunosuppression and enhance anti-tumor responses. This review explores the metabolic dependencies and pathways that sustain Treg function in OSCC, highlighting key metabolic adaptations such as glycolysis, fatty acid oxidation, amino acid metabolism and PI3K-Akt-mTOR signaling pathway that enable Tregs to thrive in the challenging conditions of the TME. Additionally, the review discusses the influence of the oral microbiome on Treg metabolism and evaluates potential therapeutic strategies targeting these metabolic pathways. Despite the promising potential of these interventions, challenges such as selectivity, toxicity, tumor heterogeneity, and resistance mechanisms remain. The review concludes with perspectives on personalized medicine and integrative approaches, emphasizing the need for continued research to translate these findings into effective clinical applications for OSCC treatment.

Tumor Metabolic Reprogramming and Ferroptosis: The Impact of Glucose, Protein, and Lipid Metabolism

Ferroptosis, a novel form of cell death discovered in recent years, is typically accompanied by significant iron accumulation and lipid peroxidation during the process. This article systematically elucidates how tumor metabolic reprogramming affects the ferroptosis process in tumor cells. The paper outlines the basic concepts and physiological significance of tumor metabolic reprogramming and ferroptosis, and delves into the specific regulatory mechanisms of glucose metabolism, protein metabolism, and lipid metabolism on ferroptosis. We also explore how complex metabolic changes in the tumor microenvironment further influence the response of tumor cells to ferroptosis. Glucose metabolism modulates ferroptosis sensitivity by influencing intracellular energetic status and redox balance; protein metabolism, involving amino acid metabolism and protein synthesis, plays a crucial role in the initiation and progression of ferroptosis; and the relationship between lipid metabolism and ferroptosis primarily manifests in the generation and elimination of lipid peroxides. This review aims to provide a new perspective on how tumor cells regulate ferroptosis through metabolic reprogramming, with the ultimate goal of offering a theoretical basis for developing novel therapeutic strategies targeting tumor metabolism and ferroptosis.

HCC Model Induced by P53 and Pten Knockout in HBV-Transgenic Mice Mirrors Human HCC at the Transcriptome Level

With a multitude of HCC mouse models available, choosing the one that most closely resembles human HCC can be challenging. This study addresses this gap by conducting a comprehensive transcriptomic similarity analysis of widely used HCC mouse models. In this study, RNA-seq was performed on a model induced by double knockout of P53 and Pten via CRISPR/Cas9 in HBV-transgenic mice. Additionally, RNA-seq data from 2345 various other models induced by different methods were collected from GEO databases. The gene expression profiles, immune microenvironments, and metabolic pathways of these models were compared with those of human HCC. The analysis revealed distinct transcriptomic features among the different models. The HBV + P53&Pten KO model demonstrated the highest overall similarity to human HCC across various parameters. It shared a high degree of overlap in differentially expression genes (DEGs) between tumor and non-tumor tissues with human HCC, exhibited a transcriptome profile and immune cell infiltration pattern closely resembling human HCC, and showed metabolic alterations similar to those in human HCC. Conversely the DEN + CCl4-induced model showed the lowest similarity to human HCC in transcriptome profiles and DEGs and exhibited a distinct immune microenvironment with high NK cell infiltration, with minimal metabolic differences between tumor and non-tumor tissues. This study highlights the importance of selecting appropriate HCC mouse models for research. The HBV + p53&Pten KO model emerged as the most promising due to its remarkable similarity to human HCC across various aspects.

YAP enhances mitochondrial OXPHOS in tumor-infiltrating Treg through upregulating Lars2 on stiff matrix

BACKGROUND

Tumor-infiltrating regulatory T cells (TI-Tregs) are well-adapted to thrive in the challenging tumor microenvironment (TME) by undergoing metabolic reprogramming, notably shifting from glycolysis to mitochondrial oxidative phosphorylation (OXPHOS) for energy production. The extracellular matrix is an important component of the TME, contributing to the regulation of both tumor and immune cell metabolism patterns by activating mechanosensors such as YAP. Whether YAP plays a part in regulating TI-Treg mitochondrial function and the underlying mechanisms are yet to be elucidated.

METHODS

To gain insights into the effect of matrix stiffness on YAP activation in Tregs, alterations in stiffness were performed both in vitro and in vivo. YAP conditional knockout mice were used to determine the role of YAP in TI-Tregs. RNA-seq, quantitative PCR, flow cytometry, lentivirus infection and mitochondrial function assay were employed to uncover the mechanism of YAP modulating mitochondrial function in TI-Tregs. A YAP inhibitor and a low leucine diet were applied to tumor-bearing mice to seek the potential antitumor strategy.

RESULTS

In this study, we found that YAP, as a mechanotransducer, was activated by matrix stiffness in TI-Tregs. A deficiency in YAP significantly hindered the immunosuppressive capability of TI-Tregs by disrupting mitochondrial function. Mechanically, YAP enhanced mitochondrial OXPHOS by upregulating the transcription of Lars2 (Leucyl-tRNA synthetase 2, mitochondrial), which was essential for mitochondrial protein translation in TI-Tregs. Since Lars2 relied much on its substrate amino acid, leucine, the combination of a low leucine diet and YAP inhibitor synergistically induced mitochondrial dysfunction in TI-Tregs, ultimately restraining tumor growth.

CONCLUSIONS

This finding uncovered a new understanding of how YAP shapes mitochondrial function in TI-Tregs in response to mechanical signals within the TME, making the combined strategy of traditional medicine and diet adjustment a promising approach for tumor therapy.

Regulatory T cells in immune checkpoint blockade antitumor therapy

Regulatory T cells (Tregs), an essential component of the human immune system, are a heterogeneous group of T lymphocytes with the ability to suppress immune responses and maintain immune homeostasis. Recent evidence indicates that Tregs may impair antitumor immunity and facilitate cancer progression by weakening functions of effector T cells (Teffs). Consequently, targeting Tregs to eliminate them from tumor microenvironments to improve Teffs' activity could emerge as an effective strategy for cancer immunotherapy. This review outlines the biology of Tregs, detailing their origins, classification, and crucial markers. Our focus lies on the complex role of Tregs in cancer's development, progression and treatment, particularly on their suppressive role upon antitumor responses via multiple mechanisms. We delve into Tregs' involvement in immune checkpoint blockade (ICB) therapy, their dual effect on cancer immunotherapy and their potential biomarkers for ICB therapy effectiveness. We also summarize advances in the therapies that adjust Tregs to optimize ICB therapy, which may be crucial for devising innovative cancer treatment strategies.

The CCR6-CCL20 Axis Promotes Regulatory T-cell Glycolysis and Immunosuppression in Tumors

Regulatory T cells (Treg) are important players in the tumor microenvironment. However, the mechanisms behind their immunosuppressive effects are poorly understood. We found that CCR6-CCL20 activity in tumor-infiltrating Tregs is associated with greater glycolytic activity and ablation of Ccr6 reduced glycolysis and lactic acid production while increasing compensatory glutamine metabolism. Immunosuppressive activity toward CD8+ T cells was abrogated in Ccr6-/- Tregs due to reduction in activation-induced glycolysis. Furthermore, Ccr6-/- mice exhibited improved survival across multiple tumor models compared to wild-type mice and Treg and CD8+ T-cell depletion abrogated the improvement. In addition, Ccr6 ablation further promoted the efficacy of anti-PD-1 therapy in a preclinical glioma model. Follow-up knockdown of Ccl20 with siRNA also demonstrated improvement in antitumor efficacy. Our results unveil CCR6 as a marker and regulator of Treg-induced immunosuppression and identify approaches to target the metabolic determinants of Treg immunosuppressive activity.

Dual immunostimulatory CD73 antibody-polymeric cytotoxic drug complex for triple negative breast cancer therapy

Treatment of triple-negative breast cancer (TNBC) poses significant challenges due to its propensity for metastasis. A key impediment lies in the suppressive immune microenvironment, which fosters tumor progression. This study introduces an approach employing a dual immune-stimulatory CD73 antibody-polymeric cytotoxic drug complex (αCD73-PLG-MMAE). This complex is designed for targeted eradication of TNBC while modulating tumor immunity through mechanisms such as immunogenic cell death (ICD) and interference with the adenosine signaling pathway. By enhancing antitumor immune responses, this strategy offers a highly effective means of treating TNBC and mitigating metastasis. The complex is synthesized by combining αCD73 with poly(L-glutamic acid) (PLG) grafted Fc binding peptides (Fc-III-4C) and Val-Cit-PAB-monomethyl auristatin E (MMAE), exploiting the affinity between αCD73 and Fc-III-4C. αCD73 selectively targets CD73 molecules on both tumor and immune suppressive cells, thereby inhibiting the adenosine pathway. Meanwhile, Val-Cit-PAB-MMAE, activated by cathepsin B, triggers selective release of MMAE, inducing ICD in tumor cells. In a 4T1 tumor model, αCD73-PLG-MMAE significantly enhances drug accumulation in tumors by 4.13-fold compared to IgG-PLG-MMAE, leading to suppression of tumor growth and metastasis. Furthermore, it synergistically augments the antitumor effects of αPD-1, resulting in a tumor inhibition rate of 92 % as compared to 21 % with αPD-1 alone. This study thus presents a pioneering therapeutic strategy for TNBC, emphasizing the potential of targeted immunomodulation in cancer treatment. STATEMENT OF SIGNIFICANCE: Antibody-drug conjugate (ADC) therapy holds promise for treating triple-negative breast cancer (TNBC). However, the current ADC, sacituzumab govitecan, fails to overcome the crucial role of adenosine in the suppressive immune microenvironment characteristic of this "cold tumor". Here, we present a dual immune-stimulatory complex, αCD73-PLG-MMAE, which targets TNBC specifically and modulates tumor immunity through mechanisms such as immunogenic cell death (ICD) and interference with the adenosine signaling pathway. Thus, it kills tumor cells with cytotoxic drugs, comprehensively regulates immunosuppression, and restores a durable immune response. This study proposes an antibody-polymeric drug complex with immunomodulatory and immunoagonist roles, offering new insights into TNBC treatment.

CD8+ T cells infiltrating into tumors were controlled by immune status of pulmonary lymph nodes and correlated with non-small cell lung cancer (NSCLC) patients' prognosis treated with chemoimmunotherapy

PURPOSE

Neoadjuvant chemoimmunotherapy has the potential to reduce tumor burden, improve the pathological complete response (pCR) rate, and significantly prolong patients' disease-free survival (DFS). However, the treatment's effectiveness varies among NSCLC patients. The immunological mechanisms contributing to tumor regression still require further exploration and elucidation.

METHODS

The immune status of patients' local tumor microenvironment (TME) before and after neoadjuvant chemoimmunotherapy, their paired pulmonary lymph nodes (11th LNs) after therapy, including infiltrating immune cell densities and their correlations, were analyzed using multiplex immunofluorescence.

RESULTS

Fifty-six NSCLC patients undergoing neoadjuvant chemoimmunotherapy were enrolled and subsequently underwent surgical resection and pathological evaluation. Among these, 19 patients achieved a pCR, 6 patients exhibited a major pathological response (MPR), and 31 patients did not achieve MPR. There were no significant difference in the densities of CD8+ T cell, Treg and Dendritic cell (DC) in patients' TME before neoadjuvant therapy (n = 26, P = 0.091, P = 0.753, P = 0.905, respectively), but after treament, these immune cells' dynamics were significantly different between different response group. CD8+ T cell densities were increased in pCR gourp (P = 0.006), but not in non-pCR group (P = 0.389); the densities of Treg were increased in non-pCR gourp (P = 0.0004), but DC were significantly decreased in non-pCR gourp (P = 0.005). After surgery, the TME were also significantly different: patients achieving pCR typically demonstrated high densities of CD8+ T cell, DC and low densities of Tregs (P = 0.0001, P < 0.0001 and P = 0.0004). The immune status of 11th LNs also exhibited significant differences. DC densities were much higher in pCR patients, whereas Treg in the pCR group were significantly lower than those in the non-pCR group (P = 0.0008 and P = 0.003). Furthermore, the densities of DC in the TME showed a moderate positive correlation with DC in 11th LNs (P = 0.0002), while the densities of Tregs in the TME exhibited a moderate negative correlation with DC densities in 11th LNs (P = 0.03). Patients who had high densities of CD8+ T cell in the resection tissues and DC in the LNs, experienced longer DFS (P = 0.048 and P = 0.024).

CONCLUSION

Immune cells in both pulmonary LNs and the TME collectively influence the remodeling of the NSCLC patient's TME, thus impacting treatment response and prognosis.

The metabolic crosstalk of cancer-associated fibroblasts and tumor cells: Recent advances and future perspectives

Tumor cells grow in a microenvironment with a lack of nutrients and oxygen. Cancer-associated fibroblasts (CAFs) as one major component of tumor microenvironment have strong ability to survive under stressful conditions through metabolic remodelling. Furthermore, CAFs are educated by tumor cells and help them adapt to the hostile microenvironment through their metabolic communication. By inducing catabolism, CAFs release nutrients into the microenvironment which are taken up by tumor cells to satisfy their metabolic requirements. Furthermore, CAFs can recycle toxic metabolic wastes produced by cancer cells into energetic substances, allowing cancer cells to undergo biosynthesis. Their metabolic crosstalk also enhances CAFs' pro-tumor phenotype and reshape the microenvironment facilitating tumor cells' metastasis and immune escape. In this review, we have analyzed the effect and mechanisms of metabolic crosstalk between tumor cells and CAFs. We also analyzed the future perspectives in this area from the points of CAFs heterogeneity, spatial metabonomics and patient-derived tumor organoids (PDOs). These information may deepen the knowledge of tumor metabolism regulated by CAFs and provide novel insights into the development of metabolism-based anti-cancer strategies.

Clinical study on changes of peripheral blood immune function indicators in adults with newly diagnosed glioblastoma during the peri-radiotherapy period

To analyze the changes of immune function-related indicators with newly diagnosed glioblastoma before and after radiotherapy and their clinical significance. Clinical data of 104 patients were analyzed. The independent samples t-test or chi-square test was used to compare changes in immune function indicators and to ascertain the differences between groups with different doses or volumes. The grading of the lowest lymphocyte count during radiotherapy was compared. The log-rank (Mantel - Cox) test of the Kaplan - Meier method was used to compare the survival rate, and the relationship of radiotherapy-related parameters, with the survival rate was evaluated by using the Spearman correlation coefficient. A Cox regression model was used to determine the relationship between various immune function indicators and prognosis. The percentages of total T lymphocytes and CD4+ T cells, the CD4-to-CD8 subset ratio, and the percentages of B cells and NKT cells showed an overall decreasing trend, whereas the percentages of CD8+ T cells and NK cells displayed an overall increasing trend. The lower CD4+ T cell percentage and CD4/CD8 ratio after radiotherapy were independent risk factors for OS. Short OS was observed in patients with grade 3 or 4 lymphopenia or with low levels of hemoglobin and serum albumin before radiotherapy. The percentage of CD4+ T cells and the CD4/CD8 ratio were higher in patients with the low tumor-irradiated volume and irradiated volume and dose of the OAR, than in patients from the corresponding high indicator group. Different irradiation dose or volume can differentially alter various immune function indicators.

Optimizing CD8+ T cell-based immunotherapy via metabolic interventions: a comprehensive review of intrinsic and extrinsic modulators

CD8+ T cells are integral to the effective management of cancer and infectious diseases due to their cytotoxic functions. The efficacy of these cells is profoundly influenced by their metabolic state, which regulates their activation, differentiation, and longevity. Accordingly, the modulation of metabolic pathways within CD8+ T cells is crucial for enhancing the effectiveness of T cell-based immunotherapy. Precise metabolic control is paramount in optimizing therapeutic outcomes and minimizing potential toxicities associated with treatment. Importantly, the potential of exogenous metabolites to augment CD8+ T cell responses is critically evaluated, especially through in vivo evidence that underscores their therapeutic promise. This review also addresses current challenges, including the need for precise control of metabolic modulation to avoid adverse effects, the development of targeted delivery systems to ensure efficient metabolite delivery to CD8+ T cells, and the inherent variability of metabolic states among patients that may influence treatment outcomes. Addressing these hurdles will be crucial for the successful integration of metabolic interventions into established immunotherapeutic regimens.

The Immune Microenvironment in Prostate Cancer: A Comprehensive Review

BACKGROUND

Prostate cancer (PCa) is a malignancy with significant immunosuppressive properties and limited immune activation. This immunosuppression is linked to reduced cytotoxic T cell activity, impaired antigen presentation, and elevated levels of immunosuppressive cytokines and immune checkpoint molecules. Studies demonstrate that cytotoxic CD8+ T cell infiltration correlates with improved survival, while increased regulatory T cells (Tregs) and tumor-associated macrophages (TAMs) are associated with worse outcomes and therapeutic resistance. Th1 cells are beneficial, whereas Th17 cells, producing interleukin-17 (IL-17), contribute to tumor progression. Tumor-associated neutrophils (TANs) and immune checkpoint molecules, such as PD-1/PD-L1 and T cell immunoglobulin-3 (TIM-3) are also linked to advanced stages of PCa. Chemotherapy holds promise in converting the "cold" tumor microenvironment (TME) to a "hot" one by depleting immunosuppressive cells and enhancing tumor immunogenicity.

SUMMARY

This comprehensive review examines the immune microenvironment in PCa, focusing on the intricate interactions between immune and tumor cells in the TME. It highlights how TAMs, Tregs, cytotoxic T cells, and other immune cell types contribute to tumor progression or suppression and how PCa's low immunogenicity complicates immunotherapy.

KEY MESSAGES

The infiltration of cytotoxic CD8+ T cells and Th1 cells correlates with better outcomes, while elevated T regs and TAMs promote tumor growth, metastasis, and resistance. TANs and natural killer (NK) cells exhibit dual roles, with higher NK cell levels linked to better prognoses. Immune checkpoint molecules like PD-1, PD-L1, and TIM-3 are associated with advanced disease. Chemotherapy can improve tumor immunogenicity by depleting T regs and myeloid-derived suppressor cells, offering therapeutic promise.

Genetically predicted N-Acetyl-L-Alanine mediates the association between CD3 on activated and secreting Tregs and Guillain-Barre syndrome

Objective

This study sought to explore the potential causal relationships among immune cell traits, Guillain-Barre syndrome (GBS) and metabolites.

Methods

Employing a two-sample Mendelian randomization (MR) approach, the study investigated the causal associations between 731 immune cell traits, 1400 metabolite levels and GBS leveraging summary-level data from a genome-wide association study (GWAS). To ensure the reliability of our findings, we further assessed horizontal pleiotropy and heterogeneity and evaluated the stability of MR results using the Leave-one-out method.

Results

This study revealed a causal relationship between CD3 on activated & secreting Tregs and GBS. Higher CD3 on activated and secreting Regulatory Tregs increased the risk of GBS (primary MR analysis odds ratio (OR) 1.31/SD increase, 95% confidence interval (CI) 1.08-1.58, p = 0.005). There was no reverse causality for GBS on CD3 on activated & secreting Tregs (p = 0.36). Plasma metabolite N-Acetyl-L-Alanine (ALA) was significantly positively correlated with GBS by using the IVW method (OR = 2.04, 95% CI, 1.26-3.30; p = 0.00038). CD3 on activated & secreting Tregs was found to be positively associated with ALA risk (IVW method, OR, 1.04; [95% CI, 1.01-1.07], p = 0.0078). Mediation MR analysis indicated the mediated proportion of CD3 on activated & secreting Tregs mediated by ALA was 10% (95%CI 2.63%, 17.4%).

Conclusion

In conclusion, our study identified a causal relationship between the level of CD3 on activated & secreting Tregs and GBS by genetic means, with a considerable proportion of the effect mediated by ALA. In clinical practice, thus providing guidance for future clinical research.

Identification of amino acids metabolomic profiling in human plasma distinguishes lupus nephritis from systemic lupus erythematosus

Lupus nephritis (LN) is an immunoinflammatory glomerulonephritis associated with renal involvement in systemic lupus erythematosus (SLE). Given the close relationship between plasma amino acids (AAs) and renal function, this study aimed to elucidate the plasma AA profiles in LN patients and identify key AAs and diagnostic patterns that distinguish LN patients from those with SLE and healthy controls. Participants were categorized into three groups: normal controls (NC), SLE, and LN. Ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was employed to quantify AA levels in human plasma. Principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) were utilized to identify key AAs. The diagnostic capacity of the models was assessed using receiver operating characteristic (ROC) curve analysis and area under the ROC curve (AUC) values. Significant alterations in plasma AA profiles were observed in LN patients compared to the SLE and NC groups. The OPLS-DA model effectively separated LN patients from the SLE and NC groups. A joint model using histidine (His), lysine (Lys), and tryptophan (Trp) demonstrated exceptional diagnostic performance, achieving an AUC of 1.0 with 100% sensitivity, specificity, and accuracy in predicting LN. Another joint model comprising arginine (Arg), valine (Val), and Trp also exhibited robust predictive performance, with an AUC of 0.998, sensitivity of 93.80%, specificity of 100%, and accuracy of 95.78% in distinguishing between SLE and LN. The joint forecasting models showed excellent predictive capabilities in identifying LN and categorizing lupus disease status. This approach provides a novel perspective for the early identification, prevention, treatment, and management of LN based on variations in plasma AA levels.

Identification of telomere-related lncRNAs and immunological analysis in ovarian cancer

Background

Ovarian cancer (OC) is a global malignancy characterized by metastatic invasiveness and recurrence. Long non-coding RNAs (lncRNAs) and Telomeres are closely connected with several cancers, but their potential as practical prognostic markers in OC is less well-defined.

Methods

Relevant mRNA and clinical data for OC were sourced from The Cancer Genome Atlas (TCGA) database. The telomere-related lncRNAs (TRLs) prognostic model was established by univariate/LASSO/multivariate regression analyses. The effectiveness of the TRLs model was evaluated and measured via the nomogram. Additionally, immune infiltration, tumor mutational load (TMB), and drug sensitivity were evaluated. We validated the expression levels of prognostic genes. Subsequently, PTPRD-AS1 knockdown was utilized to perform the CCK8 assay, colony formation assay, transwell assay, and wound healing assay of CAOV3 cells.

Results

A six-TRLs prognostic model (PTPRD-AS1, SPAG5-AS1, CHRM3-AS2, AC074286.1, FAM27E3, and AC018647.3) was established, which can effectively predict patient survival rates and was successfully validated using external datasets. According to the nomogram, the model could effectively predict prognosis. Furthermore, we detected the levels of regulatory T cells and M2 macrophages were comparatively higher in the high-risk TRLs group, but the levels of activated CD8 T cells and monocytes were the opposite. Finally, the low-risk group was more sensitive to anti-cancer drugs. The mRNA levels of PTPRD-AS1, SPAG5-AS1, FAM27E3, and AC018647.3 were significantly over-expressed in OC cell lines (SKOV3, A2780, CAOV3) in comparison to normal IOSE-80 cells. AC074286.1 were over-expressed in A2780 and CAOV3 cells and CHRM3-AS2 only in A2780 cells. PTPRD-AS1 knockdown decreased the proliferation, cloning, and migration of CAOV3 cells.

Conclusion

Our study identified potential biomarkers for the six-TRLs model related to the prognosis of OC.

Metabolic reprogramming and immune evasion: the interplay in the tumor microenvironment

Tumor cells possess complex immune evasion mechanisms to evade immune system attacks, primarily through metabolic reprogramming, which significantly alters the tumor microenvironment (TME) to modulate immune cell functions. When a tumor is sufficiently immunogenic, it can activate cytotoxic T-cells to target and destroy it. However, tumors adapt by manipulating their metabolic pathways, particularly glucose, amino acid, and lipid metabolism, to create an immunosuppressive TME that promotes immune escape. These metabolic alterations impact the function and differentiation of non-tumor cells within the TME, such as inhibiting effector T-cell activity while expanding regulatory T-cells and myeloid-derived suppressor cells. Additionally, these changes lead to an imbalance in cytokine and chemokine secretion, further enhancing the immunosuppressive landscape. Emerging research is increasingly focusing on the regulatory roles of non-tumor cells within the TME, evaluating how their reprogrammed glucose, amino acid, and lipid metabolism influence their functional changes and ultimately aid in tumor immune evasion. Despite our incomplete understanding of the intricate metabolic interactions between tumor and non-tumor cells, the connection between these elements presents significant challenges for cancer immunotherapy. This review highlights the impact of altered glucose, amino acid, and lipid metabolism in the TME on the metabolism and function of non-tumor cells, providing new insights that could facilitate the development of novel cancer immunotherapies.

Immunotherapies targeting the oncogenic fusion gene CLDN18-ARHGAP in gastric cancer

The CLDN18-ARHGAP fusion gene is an oncogenic driver newly discovered in gastric cancer. It was detected in 9% (8/87) of gastric cancer patients in our center. An immunogenic peptide specifically targeting CLDN18-ARHGAP fusion gene was generated to induce neoantigen-reactive T cells, which was proved to have specific and robust anti-tumor capacity both in in vitro coculture models and in vivo xenograft gastric cancer models. Apart from the immunogenic potential, CLDN18-ARHGAP fusion gene was also found to contribute to immune suppression by inducing a regulatory T (Treg) cell-enriched microenvironment. Mechanistically, gastric cancer cells with CLDN18-ARHGAP fusion activate PI3K/AKT-mTOR-FAS signaling, which enhances free fatty acid production of gastric cancer cells to favor the survival of Treg cells. Furthermore, PI3K inhibition could effectively reverse Treg cells upregulation to enhance anti-tumor cytotoxicity of neoantigen-reactive T cells in vitro and reduce tumor growth in the xenograft gastric cancer model. Our study identified the CLDN18-ARHGAP fusion gene as a critical source of immunogenic neoepitopes, a key regulator of the tumor immune microenvironment, and immunotherapeutic applications specific to this oncogenic fusion.

The pro-tumoral and anti-tumoral roles of EphA4 on T regulatory cells and tumor associated macrophages during HNSCC tumor progression

Head and Neck Squamous Cell Carcinoma (HNSCC) is a deadly cancer with poor response to targeted therapy, largely driven by an immunosuppressive tumor microenvironment (TME). Here we examine the immune-modulatory role of the receptor tyrosine kinase EphA4 in HNSCC progression. Within the TME, EphA4 is primarily expressed on regulatory T cells (Tregs) and macrophages. In contrast ephrinB2, an activating ligand of EphA4, is expressed in tumor blood vessels. Using genetically engineered mouse models, we show that EphA4 expressed in Tregs promotes tumor growth, whereas EphA4 expressed in monocytes inhibits tumor growth. In contrast, ephrinB2 knockout in blood vessels reduces both intratumoral Tregs and macrophages. A novel specific EphA4 inhibitor, APY-d3-PEG4, reverses the accelerated tumor growth we had previously reported with EphB4 cancer cell knockout. EphA4 knockout in macrophages not only enhanced their differentiation into M2 macrophage but also increased Treg suppressive activity. APY-d3-PEG4 reversed the accelerated growth seen in the EphA4 knockout of monocytes but conferred no additional benefit when EphA4 was knocked out on Tregs. Underscoring an EphA4-mediated interplay between Tregs and macrophages, we found that knockout of EphA4 in Tregs not only decreases their activation but also reduces tumor infiltration of pro-tumoral M2 macrophages. These data identify Tregs as a primary target of APY-d3-PEG4 and suggest a role for Tregs in regulating macrophage conversion. These data also support the possible anti-cancer therapeutic value of bispecific peptides or antibodies capable of promoting EphA4 blockade in Tregs but not macrophages.

Significance

EphA4 in regulatory T cells has a pro-tumoral effect while EphA4 in macrophages plays an anti-tumoral role underscoring the necessity of developing biologically rational therapeutics.

Immunosuppressive tumor microenvironment in the progression, metastasis, and therapy of hepatocellular carcinoma: from bench to bedside

Hepatocellular carcinoma (HCC) is a highly heterogeneous malignancy with high incidence, recurrence, and metastasis rates. The emergence of immunotherapy has improved the treatment of advanced HCC, but problems such as drug resistance and immune-related adverse events still exist in clinical practice. The immunosuppressive tumor microenvironment (TME) of HCC restricts the efficacy of immunotherapy and is essential for HCC progression and metastasis. Therefore, it is necessary to elucidate the mechanisms behind immunosuppressive TME to develop and apply immunotherapy. This review systematically summarizes the pathogenesis of HCC, the formation of the highly heterogeneous TME, and the mechanisms by which the immunosuppressive TME accelerates HCC progression and metastasis. We also review the status of HCC immunotherapy and further discuss the existing challenges and potential therapeutic strategies targeting immunosuppressive TME. We hope to inspire optimizing and innovating immunotherapeutic strategies by comprehensively understanding the structure and function of immunosuppressive TME in HCC.

Epigenetic regulation of human FOXP3+ Tregs: from homeostasis maintenance to pathogen defense

Regulatory T cells (Tregs), characterized by the expression of Forkhead Box P3 (FOXP3), constitute a distinct subset of T cells crucial for immune regulation. Tregs can exert direct and indirect control over immune homeostasis by releasing inhibitory factors or differentiating into Th-like Treg (Th-Treg), thereby actively contributing to the prevention and treatment of autoimmune diseases. The epigenetic regulation of FOXP3, encompassing DNA methylation, histone modifications, and post-translational modifications, governs the development and optimal suppressive function of Tregs. In addition, Tregs can also possess the ability to maintain homeostasis in diverse microenvironments through non-suppressive mechanisms. In this review, we primarily focus on elucidating the epigenetic regulation of Tregs as well as their multifaceted roles within diverse physiological contexts while looking forward to potential strategies involving augmentation or suppression of Tregs activity for disease management, particularly in light of the ongoing global COVID-19 pandemic.