d-lactate modulates M2 tumor-associated macrophages and remodels immunosuppressive tumor microenvironment for hepatocellular carcinoma

Potential Crosstalk Between ANXA1+ Epithelial Cells and FABP4+ TAM Cells of Ferroptosis-Related Molecular Clusters Promotes an Immunosuppressive Microenvironment in Non-Small Cell Lung Cancer

The tumor microenvironment (TME) affects tumor initiation, invasion, metastasis, and therapies. Recently, increasing evidence has demonstrated that ferroptosis plays important regulatory roles in tumourigenesis and progression. It is unclear how ferroptosis affects non-small cell lung cancer (NSCLC) progression by remodeling the TME. In this study, the single-cell RNA sequencing (scRNA-seq) data (85,562 cells, n = 18) were employed to reveal the heterogeneity of ferroptosis activation in NSCLC, and identified six ferroptosis-related molecular clusters. We found that ANXA1+ epithelial and FABP4 + TAM subpopulations were key factors in lung cancer progression and TME remodeling. In addition, the cell-cell communication analysis showed that ANXA1-FPR2/FPR1 receptor-ligand pair contributed to the formation of an immunosuppressive TME. Furthermore, we established a novel signature based on ferroptosis-related molecular clusters, and the risk score model may predict survival and response to immunotherapy. We also found that compared with responder, the expression of ANXA1 and FABP4 is higher in progressor, which indicating a higher expression of ANXA1 and FABP4 was associated with a worse response to immunotherapy. Therefore, we concluded that the molecular clusters associated with ferroptosis served as potential prognostic markers and therapeutic targets for NSCLC patients.

Drivers of centrosome abnormalities: Senescence progression and tumor immune escape

Centrosome abnormalities are a distinguishing feature of cancer and play a role in the aging process. Cancer cells may evade the immune system by activating immune checkpoints, altering their surrounding microenvironment, abnormalities in antigen presentation and recognition, and metabolic reprogramming to inhibit T-cell activity, allowing cancer cells to survive and spread within the host. When the centrosomes are abnormally shaped or numbered, mitotic errors can occur, cellular senescence occurs, cell death occurs, genomic instability occurs, and aneuploidy forms, resulting in diseases such as cancer. The present study is exploring the strategy of research progress in which centrosome abnormalities contribute to the aging process in various different ways as well as fuel immune escape from cancer cells, providing a new direction for cancer immunotherapy.

Dual-responsive magnetic vortex nanorings co-deliver lenvatinib and localized heat for synergistic activation of antitumor immunity

Hepatocellular carcinoma (HCC) presents significant treatment challenges, primarily due to its ability to suppress immune responses. Lenvatinib (LT), approved as a first-line therapy for HCC, modulates the immune microenvironment by reducing PD-L1 expression and decreasing the infiltration of regulatory T cells (Tregs) within the tumor. However, the low immunogenicity of HCC and high toxicity of LT often undermine its effectiveness. To address these challenges, polydopamine (PDA)-coated ferrimagnetic vortex-domain iron oxide nanorings (FVIO@PDA) were engineered to respond to both acidic conditions and magnetic fields, facilitating the simultaneous delivery of the drug (LT) and a physio-therapeutic heat modality. The dual-responsive nature of FVIO@PDA ensures a controlled and synergistic release of LT, activated by acidic tumor microenvironments and the heat produced by an alternating magnetic field (AMF). In a subcutaneous Hepa1-6 HCC model, LT-loaded FVIO@PDA-PEG (denoted as LT-loaded FPP)-mediated magnetic hyperthermia significantly increased the levels of cytotoxic T lymphocytes, showing an approximate 3.86-fold increase compared to the control groups. This combination of LT and magnetic hyperthermia also reduced Treg populations to 1.4 %, synergistically triggering a robust antitumor immune response. Additionally, it altered cytokine profiles, reducing the secretion of the immunosuppressive cytokine IL-10 to 0.41 times that of control levels, while increasing the secretion of pro-inflammatory cytokines IFN-γ and TNF-α by 3.25 and 4.34 times, respectively. Furthermore, LT-loaded FPP-mediated magnetic hyperthermia exhibits superior anti-tumor activity compared to either treatment alone. These results highlight the promise of combining LT with FPP-mediated immunogenic magnetic hyperthermia as a potent therapeutic strategy for HCC, offering a more effective approach to modulate the immune environment and enhance antitumor efficacy. STATEMENT OF SIGNIFICANCE: Lenvatinib (LT) is a selective multi-targeted tyrosine kinase inhibitor used for patients with unresectable HCC who have not previously undergone systemic therapy. LT's immunomodulatory effects alone are often insufficient to induce an effective immune response, and treatment outcomes continue to be unsatisfactory. We developed FVIO@PDA for the delivery of LT and localized heat. FVIO@PDA allowed for controlled release of LT, triggered by the acidic tumor microenvironment and the heat generated under an AMF. LT combined with magnetic hyperthermia increased CTLs, reduced Tregs, decreased immunosuppressive cytokines, and elevated pro-inflammatory ones, collectively initiating a strong antitumor immune response. LT combined with magnetic hyperthermia showed superior antitumor effect compared to either treatment alone.

Protocol for label-free quantitative lysine lactylproteome profiling

L-lactate has been recognized as an essential molecule for signaling and metabolic balance. Lactylation, a post-translational modification (PTM) derived from L-lactate, is commonly observed on various proteins and plays essential roles in cellular processes. Here, we present a protocol to globally profile the lactylation proteome and perform label-free quantification. We provide steps for cell preparation, protein extraction, digestion, peptide desalting, and lactylpeptide enrichment. Additionally, we outline the parameters for liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. For complete details on the use and execution of this protocol, please refer to Li et al.1.

Exosomal miR‑3681‑3p from M2‑polarized macrophages confers cisplatin resistance to gastric cancer cells by targeting MLH1

Cisplatin (DDP) is a key chemotherapeutic agent in the treatment of gastric cancer; however, its efficacy is often limited by chemoresistance, a notable challenge in clinical oncology. The present study aimed to investigate the influence of exosomes derived from M2‑polarized macrophages, which promote this resistance, on the response of gastric cancer cells to DDP, examining both the effects and the underlying mechanisms. M2 macrophages, differentiated from mouse bone marrow cells with interleukin (IL)‑13 and IL‑4, were identified using immunofluorescence staining for CD206 and CD163. Exosomes derived from these macrophages were characterized using transmission electron microscopy and protein markers, including calnexin, tumor susceptibility gene 101 and CD9. The role of exosomal microRNA (miR)‑3681‑3p in DDP resistance was assessed using Cell Counting Kit‑8 and apoptosis assays, while a luciferase reporter assay was used to elucidate the interaction between miR‑3681‑3p and MutL protein homolog 1 (MLH1). Co‑culturing gastric cancer cells with M2 macrophages enhanced DDP resistance, an effect amplified by exosomes from M2 macrophages enriched with miR‑3681‑3p. This microRNA directly targeted and reduced MLH1 protein expression. Overexpression of miR‑3681‑3p through mimic transfection, along with MLH1 silencing by small interfering RNA transfection, significantly increased DDP resistance, as evidenced by elevated IC50 values in AGS cells. By contrast, the overexpression of MLH1 effectively reversed the drug resistance of AGS cells to DDP caused by miR‑3681‑3p mimic transfection, as evidenced by a decrease in the IC50 value. In conclusion, exosomal miR‑3681‑3p from M2 macrophages may have a key role in conferring DDP resistance to gastric cancer by suppressing MLH1, offering a new therapeutic target for overcoming chemoresistance.

Impact of lactate on immune cell function in the tumor microenvironment: mechanisms and therapeutic perspectives

Lactate has emerged as a key regulator in the tumor microenvironment (TME), influencing both tumor progression and immune dynamics. As a byproduct of aerobic glycolysis, lactate satisfies the metabolic needs of proliferating tumor cells while reshaping the TME to facilitate immune evasion. Elevated lactate levels inhibit effector immune cells such as CD8+ T and natural killer cells, while supporting immunosuppressive cells, such as regulatory T cells and myeloid-derived suppressor cells, thus fostering an immunosuppressive environment. Lactate promotes epigenetic reprogramming, stabilizes hypoxia-inducible factor-1α, and activates nuclear factor kappa B, leading to further immunological dysfunction. In this review, we examined the role of lactate in metabolic reprogramming, immune suppression, and treatment resistance. We also discuss promising therapeutic strategies targeting lactate metabolism, including lactate dehydrogenase inhibitors, monocarboxylate transporter inhibitors, and TME neutralization methods, all of which can restore immune function and enhance immunotherapy outcomes. By highlighting recent advances, this review provides a theoretical foundation for integrating lactate-targeted therapies into clinical practice. We also highlight the potential synergy between these therapies and current immunotherapeutic strategies, providing new avenues for addressing TME-related challenges and improving outcomes for patients with cancer.

Pain, lactate, and anesthetics: intertwined regulators of tumor metabolism and immunity

Patients with advanced cancer frequently endure severe pain, which substantially diminishes their quality of life and can adversely impact survival. Analgesia, a critical modality for alleviating such pain, is now under scrutiny for its potential role in cancer progression, a relationship whose underlying mechanisms remain obscure. Emerging evidence suggests that lactate, once considered a metabolic byproduct, actively participates in the malignant progression of cancer by modulating both metabolic and immunological pathways within the tumor microenvironment. Furthermore, lactate is implicated in the modulation of cancer-related pain, exerting effects through direct and indirect mechanisms. This review synthesizes current understanding of lactate's production, transport, and functional roles in tumor cells, encompassing the regulation of tumor metabolism, immunity, and progression. Additionally, we dissect the complex, bidirectional relationship between lactate and pain, and assess the impact of anesthetics on pain relief, lactate homeostasis, and tumorigenesis.

Integrative single-cell and bulk RNA-seq analysis identifies lactylation-related signature in osteosarcoma

Osteosarcoma is the most common bone tumor and a highly aggressive malignant neoplasm. This study aims to elucidate the role of lactylation-related genes (LRGs) in osteosarcoma, with the goal of improving prognostic accuracy and enhancing the efficacy of immunotherapy. Using public datasets, we integrated differential and correlated genes based on single-cell sequencing AUCell scores and performed enrichment analysis and risk model construction on these genes. A total of 277 genes were found to be intricately linked with lactate metabolism. Using the uni-Cox and LASSO algorithm, nine key genes were identified, demonstrating strong predictive power for the prognosis of Osteosarcoma patients. Notably, changes were observed at the levels of immune checkpoints, the tumor microenvironment (TME), drug sensitivity, and immune cell infiltration. This study paves the way for targeted drug interventions, thereby opening avenues for improving clinical outcomes in osteosarcoma.

L- and D-Lactate: unveiling their hidden functions in disease and health

Lactate, once considered a mere byproduct of anaerobic metabolism, is now recognized as a critical signaling molecule with diverse roles in physiology and pathology. There are two stereoisomers of lactate: L- and D-lactate. Recent studies have shown that disruptions in these two lactate stereoisomers have distinct effects on health and disease. L-lactate is central to glycolysis and energy transfer through the Cori cycle but also acts as the dominant lactylation isomer induced by glycolysis, influencing metabolism and cell survival. Although less studied, D-lactate is linked to metabolic disorders and plays a role in mitochondrial dysfunction and oxidative stress. This review focuses on both L- and D-lactate and examines their biosynthesis, transport, and expanding roles in physiological and pathological processes, particularly their functions in cancer, immune regulation, inflammation, neurodegeneration and other diseases. Finally, we assess the therapeutic prospects of targeting lactate metabolism, highlighting emerging strategies for intervention in clinical settings. Our review synthesizes the current understanding of L- and D-lactate, offering insights into their potential as targets for therapeutic innovation.

Targeted nanoparticle delivery system for tumor-associated macrophage reprogramming to enhance TNBC therapy

Triple-negative breast cancer (TNBC) poses as a daunting and intricate manifestation of breast cancer, highlighted by few treatment options and a poor outlook. The crucial element in fostering tumor growth and immune resistance is the polarization of tumor-associated macrophages (TAMs) into the M2 state within the tumor microenvironment (TME). To address this, we developed M2 targeting peptide-chitosan-curcumin nanoparticles (M2pep-Cs-Cur NPs), a targeted delivery system utilizing chitosan (Cs) as a carrier, curcumin (Cur) as a therapeutic agent, and targeting peptides for specificity. These NPs effectively inhibited TNBC cell proliferation (~ 70%) and invasion (~ 70%), while increasing the responsiveness of tumors to anti-PD-L1 treatment (~ 50% survival enhancement) in vitro and in vivo. Bioinformatics analysis suggested that Cur modulates TAM polarization by influencing key genes such as COX-2, offering insights into its underlying mechanisms. This study highlights the potential of M2pep-Cs-Cur NPs to reverse M2 polarization in TAMs, providing a promising targeted therapeutic strategy to overcome immunotherapy resistance and improve TNBC outcomes.

Advances in tumor immunotherapy targeting macrophages

INTRODUCTION

In recent years, immunotherapy has shown significant therapeutic potential in patients with advanced tumors. However, only a small number of individuals benefit, mainly due to the tumor microenvironment (TME), which provides conditions for the development of tumors. Macrophages in TME, known as tumor-associated macrophages (TAM), are mainly divided into M1 anti-tumor and M2 pro-tumor phenotypes, which play a regulatory role in various stages of tumorigenesis, promote tumorigenesis and metastasis, and cause immunotherapy resistance.

AREAS COVERED

This review focuses on research strategies and preclinical/clinical research progress in translating TAM into antitumor phenotype by referring to the PubMed database for five years. These include small molecule chemotherapy drug development, metabolic regulation, gene editing, physical stimulation, nanotechnology-mediated combination therapy strategies, and chimeric antigen receptor-based immunotherapy.

EXPERT OPINION

It is necessary to explore the surface-specific receptors and cell signaling pathways of TAM further to improve the specificity and targeting of drugs and to strengthen research in the field of probes that can monitor changes in TAM in real time. In addition, the physical stimulation polarization strategy has the advantages of being noninvasive, economical, and stable and will have excellent clinical transformation value in the future.

ACT001 Suppresses the Malignant Progression of Small-Cell Lung Cancer by Inhibiting Lactate Production and Promoting Anti-Tumor Immunity

BACKGROUND

Improving the "cold" tumor immune microenvironment (TIME) of small-cell lung cancer (SCLC) represents a promising therapeutic approach. The metabolite lactate plays a crucial role in shaping the immune-cold tumor microenvironment (TME) and facilitating tumor progression. Phosphoglycerate kinase 1 (PGK1) is a key enzyme involved in tumor lactate metabolism. This study demonstrates that ACT001 improves the TIME of SCLC through inhibiting lactate production by targeting PGK1.

METHODS

The cytotoxic effects of ACT001 on SCLC cell lines NCI-H1688 and NCI-H446 were evaluated using MTT assay, clone formation, EdU incorporation, wound healing, and invasion assays. To elucidate the mechanism of action of ACT001, proteomic techniques, pull-down assays, LC-MS/MS, surface plasmon resonance, immunofluorescence, lactate generation, glucose uptake, and western blot assays were conducted. A xenograft model was used to assess the in vivo anti-tumor activity of ACT001.

RESULTS

ACT001 inhibited the proliferation, invasion, and metastasis of SCLC both in vitro and in vivo. Additionally, it reduced lactate accumulation and M2 macrophage polarization. Mechanistically, ACT001 released micheliolide, which covalently modified Cys316 of PGK1 under physiological conditions. This suppressed PGK1 activity and restored the distribution of PGK1 in mitochondria and the cytoplasm under hypoxic conditions.

CONCLUSIONS

ACT001 inhibits the malignant progression of SCLC by suppressing lactate production, modulating macrophage polarization, and restraining tumor metastasis through PGK1 targeting.

Mitochondrial-uncoupling nanomedicine for self-heating and immunometabolism regulation in cancer cells

Developing endogenous hyperthermia offers a promising strategy to address challenges with current exogenous hyperthermia techniques in clinics. Herein, a CD44-targeted and thermal-responsive nanocarrier was developed for the simultaneous delivery of 2,4-dinitrophenol and syrosingopine. The objective was to induce endogenous hyperthermia and regulate immunometabolism, ultimately augmenting anti-tumour immune responses. Dinitrophenol as mitochondrial uncoupler can convert electrochemical potential energy of inner mitochondrial membrane into heat, facilitating endogenous hyperthermia. Meanwhile, syrosingopine not only inhibits excessive lactate efflux caused by dinitrophenol but also downregulates tumour cell glycolysis, thus alleviating immunosuppression and heat shock protein (HSP)-dependent thermo-resistance through immunometabolism regulation. The synergistic effects of endogenous hyperthermia and immunometabolism regulation by this nanomedicine have potential to enhance tumor immunogenicity, reshape the tumour immune microenvironment, and effectively suppress the growth of subcutaneous tumours and patient-derived organoids in triple-negative breast cancer. Therefore, the endogenous hyperthermia strategy developed in this study would revolutionize hyperthermia for cancer treatment.

Construction and validation of a cell death-related genes prognosis signature of hepatocellular carcinoma

Background

The cell death pathway, including apoptosis, autophagy, and necroptosis, plays an essential role in hepatocellular carcinoma (HCC) progression and outcome. However, the integration of the three cell death pathways into a prognostic signature has not yet been reported in HCC. This study aimed to investigate the association among cell death-related genes (CDRGs), prognosis, immune microenvironment, and immune checkpoint.

Methods

The RNA expression profiles and corresponding clinical data of HCC were retrieved from The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO), and International Cancer Genome Consortium (ICGC). Univariate Cox regression analysis was performed to identify the relevant prognostic genes, and Lasso Cox regression analysis was employed to calculate the risk score. The relationship between the risk score and clinicopathological characteristics, immune cell infiltration, and immune checkpoint expression was analyzed.

Results

A prognostic risk model for HCC was constructed from the identified CDRGs and patients were subgrouped based on risk score. High-risk patients for HCC exhibited a significantly lower overall survival (OS) rate than the low-risk patients. In addition, the receiver operating characteristic (ROC) curve demonstrated the predictive ability of the risk score. Patients in the high-risk group exhibited lower immune cell infiltration and higher expression levels of immune checkpoint molecules.

Conclusions

The cell death-related signature established herein provides a valuable predictive tool for survival and holds promise as a potential therapeutic biomarker for HCC.

Emerging insights into the gut microbiota as a key regulator of immunity and response to immunotherapy in hepatocellular carcinoma

The gut microbiota, a complex microbial ecosystem closely connected to the liver via the portal vein, has emerged as a critical regulator of liver health and disease. Numerous studies have underscored its role in the onset and progression of liver disorders, including alcoholic liver disease, metabolic dysfunction-associated steatotic liver disease (MASLD), metabolic dysfunction-associated steatohepatitis (MASH), liver fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). This review provides a comprehensive overview of current insights into the influence of the gut microbiota on HCC progression, particularly its effects on immune cells within the HCC tumor microenvironment (TME). Furthermore, we explore the potential of gut microbiota-targeted interventions, such as antibiotics, probiotics, prebiotics, and fecal microbiota transplantation (FMT), to modulate the immune response and improve outcomes of immunotherapy in HCC. By synthesizing insights from recent studies, this review aims to highlight microbiota-based strategies that may enhance immunotherapy outcomes, advancing personalized approaches in HCC treatment.

CpG-Based Nanovaccines Enhance Ovarian Cancer Immune Response by Gbp2-Mediated Remodeling of Tumor-Associated Macrophages

CpG oligodeoxynucleotides (CpG), as an immunoadjuvant, can facilitate the transformation of tumor-associated macrophages (TAMs)into tumoricidal M1 macrophages. However, the accumulation of free CpG in tumor tissues remains a substantial challenge. To address this, a nanovaccine (PLGA-CpG@ID8-M) is engineered by encapsulating CpG within PLGA using ID8 ovarian cancer cell membranes (ID8-M). This nanovaccine demonstrates remarkable efficacy in reprogramming TAMs in ovarian cancer and significantly extends survival in ID8-bearing mice. Notably, these findings indicate that the nanovaccine can also mitigate chemotherapy-induced immunosuppression by increasing the proportion of M1-like TAMs and reducing the expression of CD47 on tumor cells, thereby achieving a synergistic effect in tumor immunotherapy. Mechanistically, through transcriptome sequencing (RNA-seq), single-cell RNA sequencing (scRNA-seq), and mass spectrometry-based proteomics, it is elucidated that the nanovaccine enhances the expression of Gbp2 and promotes the recruitment of Pin1, which activates the NFκB signaling pathway, leading to the M1 polarization of TAMs. Furthermore, macrophages with elevated Gbp2 expression significantly inhibit tumor growth in both ID8 ovarian cancer and 4T1 breast cancer models. Conversely, targeting Gbp2 diminishes the antitumor efficacy of the nanovaccine in vivo. This study offers an innovative approach to immunotherapy and elucidates a novel mechanism (Gbp2-Pin1-NFκB pathway) for remodeling TAMs.

KAT7-acetylated YBX1 promotes hepatocellular carcinoma proliferation by reprogramming nucleotide metabolism

BACKGROUND

Lysine acetylation is a critical post-translational modification regulating tumor initiation and progression. Lysine acetyltransferase 7 (KAT7)-mediated lysine acetylation is frequently dysregulated in cancer. However, the role of KAT7-mediated lysine acetylation in hepatocellular carcinoma (HCC) progression remains unclear.

METHODS

Bioinformatic analysis was used to investigate the expression, clinicopathological characteristics and diagnostic prognostic value of KAT7 in HCC. CCK-8 assays, colony-forming assays, apoptosis assays and nude mouse xenograft models were utilized to detect the oncogenic functions of KAT7 in HCC. Immunoprecipitation (IP) assay and mass spectrometry (MS) analysis were performed to identify the KAT7-binding protein Y-box binding protein 1 (YBX1). Transcriptome sequencing and functional enrichment analysis were employed to elucidate the downstream pathway regulated by KAT7 and YBX1. Chromatin immunoprecipitation (ChIP) assay was used to evaluate YBX1 binding to the promoter regions of ribonucleotide reductase regulatory subunit M2 (RRM2) and thymidine kinase 1 (TK1). Weighted gene co-expression network analysis and selection operator regression analysis were used to build risk prediction models.

RESULTS

This study demonstrated that elevated KAT7 expression is associated with poor prognosis in HCC patients. Knockdown of endogenous KAT7 in HCC cells attenuated tumorigenic phenotypes associated with cell proliferation, colony formation and orthotopic xenograft tumor growth, indicating a pro-tumorigenic role of KAT7 in HCC. YBX1 was identified as a novel non-histone substrate for KAT7, and the E508 residue of KAT7 is essential for binding. Following the functional enrichment analysis, KAT7 and YBX1 were correlated with nucleotide metabolism. Furthermore, KAT7 binds to YBX1 and modulates its post-translational expression, which enhances the transcriptional activity of the central nucleotide metabolism enzymes RRM2 and TK1. Additionally, we constructed a novel prognostic prediction model based on KAT7, YBX1, RRM2 and TK1, which validated the predictive accuracy and prognostic value of KAT7-mediated acetylation is consistent with clinical outcomes in HCC.

CONCLUSIONS

Our findings highlight that KAT7 acetylates YBX1 and promotes HCC progression by reprogramming nucleotide metabolism, offering therapeutic implications.

High-ammonia microenvironment promotes stemness and metastatic potential in hepatocellular carcinoma through metabolic reprogramming

BACKGROUND

Hepatocellular carcinoma (HCC) is a prevalent and aggressive form of liver cancer, characterized by frequent recurrence and metastasis, which remain significant obstacles to effective treatment. Ammonia accumulates in the tumor microenvironment of HCC due to dysfunction in the urea cycle, but the detailed impact of ammonia on HCC cells remains insufficiently understood.

METHODS

We exposed HCC cell lines to high concentrations of ammonium chloride to evaluate alterations in proliferation, stemness, and migratory potential. After ammonia removal, changes in cellular behavior were assessed using colony formation, and spheroid assays. Transcriptomic and metabolomic analyses were conducted to investigate ammonia-induced metabolic reprogramming and alterations in gene expression. Additionally, animal models were employed to validate the impact of ammonia on tumor growth and metastasis.

RESULTS

Exposure to high-ammonia conditions transiently suppressed HCC cell proliferation without inducing apoptosis. However, following ammonia removal, cells demonstrated increased proliferation, enhanced spheroid formation, and elevated migratory capacity. Transcriptomic analysis revealed the upregulation of genes associated with cell adhesion, migration, and glycolysis. Concurrently, metabolomic profiling indicated increased lactate production, facilitating the aggressive behavior of HCC cells after ammonia withdrawal. Animal experiments confirmed that high-ammonia exposure accelerated tumor growth and metastasis.

CONCLUSION

Ammonia exerts a dual effect on HCC progression: it initially suppresses cell growth but later promotes stemness, proliferation, and metastasis through metabolic reprogramming. Targeting ammonia metabolism or glycolysis in the tumor microenvironment may represent a promising therapeutic strategy for mitigating HCC recurrence and metastasis. Future studies utilizing clinical samples are required to validate these findings and identify potential therapeutic strategies targeting ammonia metabolism.

Could intratumoural microbiota be key to unlocking treatment responses in hepatocellular carcinoma?

Hepatocellular carcinoma (HCC) is the third cause of cancer-related mortality worldwide. Current treatments include surgery and immunotherapy with variable response. Despite aggressive treatment, disease progression remains the biggest contributor to mortality. Thus, there is an urgent unmet need to improve current treatments through a better understanding of HCC tumourigenesis. The gut microbiota has been intensively examined in the context of HCC, with evidence showing gut modulation has the potential to modulate tumourigenesis and prognosis. In addition, recent literature suggests the presence of an intratumoural microbiota that may exert significant impacts on the development of solid tumours including HCC. By drawing parallels between the gut and hepatic/tumoural microbiota, we explore in the present review how the hepatic microbiota is established, its impact on tumourigenesis, and how modulation of the gut and hepatic microbiota may be key to improving current treatments of HCC. In particular, we highlight key bacteria that have been discovered in HCC tumours, and how they may affect the tumour immune microenvironment and HCC tumourigenesis. We then explore current therapies that target the intratumoural microbiota. With a deeper understanding of how the intratumoural microbiota is established, how different bacteria may be involved in HCC tumourigenesis, and how they can be targeted, we hope to spark future research in validating intratumoural microbiota as an avenue for improving treatment responses in HCC.

Tumor-Associated Macrophages Nano-Reprogrammers Induce "Gear Effect" to Empower Glioblastoma Immunotherapy

Glioblastoma (GBM), the most malignant brain tumor with high prevalence, remains highly resistant to the existing immunotherapies due to the significant immunosuppression within tumor microenvironment (TME), predominantly manipulated by M2-phenotypic tumor-associated macrophages (M2-TAMs). Here in this work, an M2-TAMs targeted nano-reprogrammers, MG5-S-IMDQ, is established by decorating the mannose molecule as the targeting moiety as well as the toll-like receptor (TLR) 7/8 agonist, imidazoquinoline (IMDQ) on the dendrimeric nanoscaffold. MG5-S-IMDQ demonstrated an excellent capacity of penetrating the blood-brain barrier (BBB) as well as selectively targeting M2-TAMs in the GBM microenvironment, leading to a phenotype transformation and function restoration of TAMs shown as heightened phagocytic activity toward tumor cells, enhanced cytotoxic effects, and improved tumor antigen cross-presentation capability. In the meantime, by induction of a function-oriented "gear effect", MG5-S-IMDQ treatment extended its impact systemically by enhancing the infiltration of type I conventional dendritic cells (cDC1s) into the tumor sites and bolstering adaptive immune responses. In sum, by precisely working on M2-TAMs as a unique target in tumor situ, the nano-reprogrammers successfully established a robust immune network that worked synergistically to combat tumors. This facile nanoplatform-based immunomodulatory strategy, serving as a powerful and convenient immune monotherapy or as a complementary treatment alongside other therapies like surgery, provided deep insights for advancing translational study in GBM.

Advanced Polymeric Nanoparticles for Cancer Immunotherapy: Materials Engineering, Immunotherapeutic Mechanism and Clinical Translation

Cancer immunotherapy, which leverages immune system components to treat malignancies, has emerged as a cornerstone of contemporary therapeutic strategies. Yet, critical concerns about the efficacy and safety of cancer immunotherapies remain formidable. Nanotechnology, especially polymeric nanoparticles (PNPs), offers unparalleled flexibility in manipulation-from the chemical composition and physical properties to the precision control of nanoassemblies. PNPs provide an optimal platform to amplify the potency and minimize systematic toxicity in a broad spectrum of immunotherapeutic modalities. In this comprehensive review, the basics of polymer chemistry, and state-of-the-art designs of PNPs from a physicochemical standpoint for cancer immunotherapy, encompassing therapeutic cancer vaccines, in situ vaccination, adoptive T-cell therapies, tumor-infiltrating immune cell-targeted therapies, therapeutic antibodies, and cytokine therapies are delineated. Each immunotherapy necessitates distinctively tailored design strategies in polymeric nanoplatforms. The extensive applications of PNPs, and investigation of their mechanisms of action for enhanced efficacy are particularly focused on. The safety profiles of PNPs and clinical research progress are discussed. Additionally, forthcoming developments and emergent trends of polymeric nano-immunotherapeutics poised to transform cancer treatment paradigms into clinics are explored.

AFP shields hepatocellular carcinoma from macrophage phagocytosis by regulating HuR-mediated CD47 translocation in cellular membrane

OBJECTIVES

Alpha fetoprotein(AFP) overexpression connecting with macrophage dysfunction remain poorly defined. In this study, explore AFP regulates macrophage immunomodulation in hepatocellular carcinoma(HCC) through comprehensive in vitro and in vivo studies.

METHODS

Immunohistochemical and immunofluorescence staining was used to analyze the relativity of AFP and cellular membrane CD47 expression in clinical 30 HCC tissues, and the expression of AFP and CD47 in HCC cells. The intelligent living-cell high-throughput imaging analyzer was applied to dynamically track and image of macrophages to phagocytize HCC cells. The effect of AFP on regulating the level of CD47 in cellular membrane and growth of tumor in vivo was performed by animal experiment. The association of AFP and CD47 in HCC cells was detected by single cell analysis.

RESULTS

The present results indicated that AFP upregulated the localization of CD47 on the HCC cell surface. CD47 overexpression stimulates HCC to escape immune surveillance by transmitting "don't eat me" signals to macrophages, lead to inhibit macrophage to phagocytize HCC cells. Mechanistically, the results demonstrated that AFP enhanced CD47 membrane translocation by interacting with Hu-Antigen R(HuR), an RNA-binding protein that regulates mRNA stability and translation. AFP alters the subcellular distribution of HuR, increasing its cytoplasmic accumulation and binding to CD47 transcript.

CONCLUSIONS

AFP enhanced CD47 membrane translocation by interacting with HuR. These findings proved that AFP could inhibit macrophage to phagocytize HCC cells by upregulating the localization of CD47 on the HCC cell surface. Combination of AFP with CD47 blockade may be a potential therapeutic strategy for HCC treatment.

Lactylation: The metabolic accomplice shaping cancer's response to radiotherapy and immunotherapy

Protein lactylation, an emerging post-translational modification, is providing new insights into tumor biology and challenging our current understanding of cancer mechanisms. Our review illuminates the intricate roles of lactylation in carcinogenesis, tumor progression, and therapeutic responses, positioning it as a critical linchpin connecting metabolic reprogramming, epigenetic modulation, and treatment outcomes. We provide an in-depth analysis of lactylation's molecular mechanisms and its far-reaching impact on cell cycle regulation, immune evasion strategies, and therapeutic resistance within the complex tumor microenvironment. Notably, this review dissects the paradoxical nature of lactylation in cancer immunotherapy and radiotherapy. While heightened lactylation can foster immune suppression and radioresistance, strategically targeting lactylation cascades opens innovative avenues for amplifying the efficacy of current treatment paradigms. We critically evaluate lactylation's potential as a robust diagnostic and prognostic biomarker and explore frontier therapeutic approaches targeting lactylation. The synergistic integration of multi-omics data and artificial intelligence in lactylation research is catalyzing significant strides towards personalized cancer management. This review not only consolidates current knowledge but also charts a course for future investigations. Key research imperatives include deciphering tumor-specific lactylation signatures, optimizing synergistic strategies combining lactylation modulation with immune checkpoint inhibitors and radiotherapy, and comprehensively assessing the long-term physiological implications of lactylation intervention. As our understanding of lactylation's pivotal role in tumor biology continues to evolve, this burgeoning field promises to usher in transformative advancements in cancer diagnosis, treatment modalitie.

Revisiting of Cancer Immunotherapy: Insight from the Dialogue between Glycolysis and PD-1/PD-L1 Axis in the Tumor Microenvironment

The interplay between metabolic pathways and immune escape has emerged as a captivating research area in oncobiology. Among these, the Warburg effect stands out as a hallmark metabolic reprogramming in cancer, characterized by elevated glucose utilization and excessive lactic acid production through anaerobic glycolysis. Key glycolytic enzymes not only fulfill the bioenergetic demands of cancer cells but also exhibit moonlighting roles, including regulation of epigenetic modifications, protein kinase activity, and immune escape mechanisms, thereby reshaping the tumor microenvironment. Tumor-specific vascular architecture facilitates lactate accumulation, which drives tumor progression by impairing immune cell function and acting as a signaling molecule to recruit immunosuppressive cells and modulate immune checkpoint pathways. The PD-1/PD-L1 co-stimulatory pathway plays a crucial role in negatively modulating the activation, proliferation, and cytokine secretion by T-lymphocytes. This review primarily focuses on elucidating the regulation and mechanisms underlying PD-1/PD-L1 signaling axis during glycolysis in tumor cells as well as surrounding cells. In the era of precision medicine, there is a particular interest in leveraging 18F-FDG PET/CT imaging as a valuable tool to assess PD-L1 expression status for more targeted therapeutic interventions. Additionally, the development of natural compounds capable of modulating metabolism opens new avenues for metabolism-based immunotherapy, though further studies are required to validate their in vivo efficacy.

Lactate-induced protein lactylation in cancer: functions, biomarkers and immunotherapy strategies

Lactate, long viewed as a byproduct of glycolysis and metabolic waste. Initially identified within the context of yogurt fermentation, lactate's role extends beyond culinary applications to its significance in biochemical processes. Contemporary research reveals that lactate functions not merely as the terminal product of glycolysis but also as a nexus for initiating physiological and pathological responses within the body. Lysine lactylation (Kla), a novel post-translational modification (PTM) of proteins, has emerged as a pivotal mechanism by which lactate exerts its regulatory influence. This epigenetic modification has the potential to alter gene expression patterns, thereby impacting physiological and pathological processes. Increasing evidence indicates a correlation between lactylation and adverse prognosis in various malignancies. Consequently, this review article aims to encapsulate the proteins that interact with lactate, elucidate the role of lactylation in tumorigenesis and progression, and explore the potential therapeutic targets afforded by the modulation of lactylation. The objective of this review is to clarify the oncogenic significance of lactylation and to provide a strategic framework for future research directions in this burgeoning field.

Recent advances of lysine lactylation in prokaryotes and eukaryotes

Lysine lactylation is a newly discovered protein post-translational modification that plays regulatory roles in cell metabolism, growth, reprogramming, and tumor progression. It utilizes lactate as the modification precursor, which is an end product of glycolysis while functioning as a signaling molecule in cells. Unlike previous reviews focused primarily on eukaryotes, this review aims to provide a comprehensive summary of recent knowledge about lysine lactylation in prokaryotes and eukaryotes. The current identification and enrichment strategies for lysine lactylation are introduced, and the known readers, writers, and erasers of this modification are summarized. In addition, the physiological and pathological implications of lysine lactylation are reviewed for different organisms, especially in prokaryotic cells. Finally, we end with a discussion of the limitations of the studies so far and propose future directions for lysine lactylation investigations.

Engineering immunity using metabolically active polymeric nanoparticles

Immune system functions play crucial roles in both health and disease, and these functions are regulated by their metabolic programming. The field of immune engineering has emerged to develop therapeutic strategies, including polymeric nanoparticles (NPs), that can direct immune cell phenotype and function by directing immunometabolic changes. Precise control of bioenergetic processes may offer the opportunity to prevent undesired immune activity and improve disease-specific outcomes. In this review we discuss the role that polymeric NPs can play in shaping immunometabolism and subsequent immune system activity through particle-mediated delivery of metabolically active agents as either structural components or cargo.

Single-cell Atlas reveals core function of CPVL/MSR1 expressing macrophages in the prognosis of triple-negative breast cancer

Background

Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer, with the worst prognosis among all subtypes. The impact of distinct cell subpopulations within the tumor microenvironment (TME) on TNBC patient prognosis has yet to be clarified.

Methods

Utilizing single-cell RNA sequencing (scRNA-seq) integrated with bulk RNA sequencing (bulk RNA-seq), we applied Cox regression models to compute hazard ratios, and cross-validated prognostic scoring using a GLMNET-based Cox model. Cell communication analysis was used to elucidate the potential mechanisms of CPVL and MSR1. Ultimately, RNA interference-mediated gene knockdown was utilized to validate the impact of specific genes on the polarization of tumor-associated macrophages (TAMs).

Results

Our findings revealed that the function of immune cells is more pivotal in prognosis, with TAMs showing the strongest correlation with TNBC patient outcomes, compared with other immune cells. Additionally, we identified CPVL and MSR1 as critical prognostic genes within TAMs, with CPVL expression positively correlated with favorable outcomes and MSR1 expression associated with poorer prognosis. Mechanistically, CPVL may contribute to favorable prognosis by inhibiting the SPP1-CD44 ligand-receptor and promoting CXCL9-CXCR3, C3-C3AR1 ligand-receptor, through which TAMs interact with other cells such as monocytes, neutrophils, and T cells. Moreover, cytokines including IL-18, IFNγR1, CCL20, and CCL2, along with complement-related gene like TREM2 and complement component CFD, may participate in the process of CPVL or MSR1 regulating macrophage polarization. Furthermore, RT-PCR experiments confirmed that CPVL is positively associated with M1-like TAM polarization, while MSR1 is linked to M2-like TAM polarization. Finally, the prognostic significance of these two genes is also validated in HER2-positive breast cancer subtypes.

Conclusions

CPVL and MSR1 are potential biomarkers for macrophage-mediated TNBC prognosis, suggesting the therapeutic potential of macrophage targeting in TNBC.

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.

Targeting caspase-8: a new strategy for combating hepatocellular carcinoma

Hepatocellular carcinoma (HCC) represents the most prevalent form of primary liver cancer and has a high mortality rate. Caspase-8 plays a pivotal role in an array of cellular signaling pathways and is essential for the governance of programmed cell death mechanisms, inflammatory responses, and the dynamics of the tumor microenvironment. Dysregulation of caspase-8 is intricately linked to the complex biological underpinnings of HCC. In this manuscript, we provide a comprehensive review of the regulatory roles of caspase-8 in apoptosis, necroptosis, pyroptosis, and PANoptosis, as well as its impact on inflammatory reactions and the intricate interplay with critical immune cells within the tumor microenvironment, such as tumor-associated macrophages, T cells, natural killer cells, and dendritic cells. Furthermore, we emphasize how caspase-8 plays pivotal roles in the development, progression, and drug resistance observed in HCC, and explore the potential of targeting caspase-8 as a promising strategy for HCC treatment.

The Role of Macrophages in Hepatocellular Carcinoma and Their Therapeutic Potential

Hepatocellular carcinoma (HCC) represents a significant clinical burden globally and is predicted to continue to increase in incidence for the foreseeable future. The treatment of HCC is complicated by the fact that, in the majority of cases, it develops on a background of advanced chronic inflammatory liver disease. Chronic inflammation can foster an immunosuppressive microenvironment that promotes tumour progression and metastasis. In this setting, macrophages make up a major immune component of the HCC tumour microenvironment, and in this review, we focus on their contribution to HCC development and progression. Tumour-associated macrophages (TAMs) are largely derived from infiltrating monocytes and their potent anti-inflammatory phenotype can be induced by factors that are found within the tumour microenvironment, such as growth factors, cytokines, hypoxia, and extracellular matrix (ECM) proteins. In general, experimental evidence suggest that TAMs can exhibit a variety of functions that aid HCC tumour progression, including the promotion of angiogenesis, resistance to drug therapy, and releasing factors that support tumour cell proliferation and metastasis. Despite their tumour-promoting profile, there is evidence that the underlying plasticity of these cells can be targeted to help reprogramme TAMs to drive tumour-specific immune responses. We discuss the potential for targeting TAMs therapeutically either by altering their phenotype within the HCC microenvironment or by cell therapy approaches by taking advantage of their infiltrative properties from the circulation into tumour tissue.

Targeting CA9 restricts pancreatic cancer progression through pH regulation and ROS production

PURPOSE

Lactate is a key metabolite produced by glycolytic metabolism, yet it also serves as an energy source for cancer cells. Lactate accumulation in the tumor microenvironment (TME) has been demonstrated to correlate with immunosuppressive TME and tumor progression. As a highly glycolytic tumor, it is crucial to decipher the underlying mechanism in pancreatic ductal adenocarcinoma (PDAC).

METHODS

Bioinformation analysis was used to identify lactate mediated carbonic anhydrase IX (CA9) upregulation. CCK-8, colony formation and mouse xenograft assay were utilized to study the effect of CA9 in PDAC. ECAR, OCR and pHi measurement confirmed the impacts of CA9 in Warburg phenotype. Using confocal microscopy, flow cytometry, qRT-PCR, co-IP, we validated the signaling pathways in PDAC to regulate reactive oxygen species (ROS) production.

RESULTS

We confirmed that CA9 is highly expressed in PDAC and positively regulated by lactate levels. CA9 can enhance the proliferative and migratory capabilities of PDAC cells. Pharmacologic inhibition or knockdown of CA9 significantly reduce pHi, increase the intracellular lactate and reverse the Warburg phenotype. The intracellular lactate accumulation caused by CA9 knockdown upregulates ROS and mitochondrial dysfunction. Furthermore, it was discovered that the competitive binding of CA9 with FUS inhibits the facilitation of FUS on NOX4 pre-mRNA splicing.

CONCLUSION

Collectively, our data illustrate that CA9 has a direct regulatory role in pHi homeostasis and ROS production, providing a potential therapeutic target for PDAC treatment.

Alcohol-associated liver cancer

Heavy alcohol intake induces a wide spectrum of liver diseases ranging from steatosis, steatohepatitis, cirrhosis, and HCC. Although alcohol consumption is a well-known risk factor for the development, morbidity, and mortality of HCC globally, alcohol-associated hepatocellular carcinoma (A-HCC) is poorly characterized compared to viral hepatitis-associated HCC. Most A-HCCs develop after alcohol-associated cirrhosis (AC), but the direct carcinogenesis from ethanol and its metabolites to A-HCC remains obscure. The differences between A-HCC and HCCs caused by other etiologies have not been well investigated in terms of clinical prognosis, genetic or epigenetic landscape, molecular mechanisms, and heterogeneity. Moreover, there is a huge gap between basic research and clinical practice due to the lack of preclinical models of A-HCC. In the current review, we discuss the pathogenesis, heterogeneity, preclinical approaches, epigenetic, and genetic profiles of A-HCC, and discuss the current insights into and the prospects for future research on A-HCC. The potential effect of alcohol on cholangiocarcinoma and liver metastasis is also discussed.

Application of nanotechnology in the treatment of hepatocellular carcinoma

Hepatocellular carcinoma is the predominant histologic variant of hepatic malignancy and has become a major challenge to global health. The increasing incidence and mortality of hepatocellular carcinoma has created an urgent need for effective prevention, diagnosis, and treatment strategies. This is despite the impressive results of multiple treatments in the clinic. However, the unique tumor immunosuppressive microenvironment of hepatocellular carcinoma increases the difficulty of treatment and immune tolerance. In recent years, the application of nanoparticles in the treatment of hepatocellular carcinoma has brought new hope for tumor patients. Nano agents target tumor-associated fibroblasts, regulatory T cells, myeloid suppressor cells, tumor-associated macrophages, tumor-associated neutrophils, and immature dendritic cells, reversed the immunosuppressive microenvironment of hepatocellular carcinoma. In addition, he purpose of this review is to summarize the advantages of nanotechnology in guiding surgical excision, local ablation, TACE, standard chemotherapy, and immunotherapy, application of nano-vaccines has also continuously enriched the treatment of liver cancer. This study aims to investigate the potential applications of nanotechnology in the management of hepatocellular carcinoma, with the ultimate goal of enhancing therapeutic outcomes and improving the prognosis for patients affected by this malignancy.

Crosstalk between lactate and tumor-associated immune cells: clinical relevance and insight

Lactate, which was traditionally viewed as a metabolic byproduct of anaerobic glycolysis, has emerged as a significant signaling molecule involved in the development of tumors. Current studies highlight its dual function, where it not only fuels tumor development but also modulates immune responses. Lactate has an effect on various tumor-associated immune cells, promoting immunosuppressive conditions that facilitate tumor growth and immune evasion. This phenomenon is strongly associated with the Warburg effect, a metabolic shift observed in many cancers that favors glycolysis over oxidative phosphorylation, resulting in elevated lactate production. Exploring the complex interplay between lactate metabolism and tumor immunity provides a novel understanding regarding the mechanisms of tumor immune evasion and resistance to therapies. This review discusses the unique biology of lactate in the TME, its impact on immune cell dynamics, and its potential as a tumor treatment target.

Delivery of SiRNA-PD-L1 by attenuated Salmonella in combination with oxaliplatin in a hepatocellular carcinoma mouse model

Oxaliplatin is currently used for chemotherapy in patients with hepatocellular carcinoma, but its increasing tolerance to tumours over time limits its clinical application. Studies have shown that high PD-L1 expression promotes the polarization of M2 macrophages. The increased infiltration of M2 macrophages, including those in HCC, is positively correlated with poor prognosis in various solid tumours. We found that oxaliplatin promoted the expression of PD-L1 in liver cancer cells, which might be attributed partly to the tolerance of tumours to oxaliplatin. Therefore, in this study, we explored the antitumour effect of attenuated Salmonella carrying siRNA-PD-L1 combined with oxaliplatin via Western blotting, immunohistochemistry, immunofluorescence, and flow cytometry. The results revealed that attenuated Salmonella carrying siRNA-PD-L1 combined with oxaliplatin more significantly inhibited tumour growth in tumour-bearing mice, suppressed the expression of PD-L1 in tumour tissue, increased the apoptosis of tumour cells and the expression of the tumour-related protein cleaved-caspase3, and increased the infiltration of M1 macrophages and T lymphocytes in tumour tissues. Moreover, the combination therapy increased the activation of T cells and the number of T lymphocytes and NK cells in the spleens of the mice and improved the overall antitumour immune response in the mice. Our results confirmed that attenuated Salmonella harbouring siRNA-PD-L1 combined with oxaliplatin had a significant antitumour effect and did not increase the incidence of toxic side effects, providing a theoretical reference for addressing oxaliplatin tolerance in the treatment of hepatocellular carcinoma.

Abnormally activated wingless/integrated signaling modulates tumor-associated macrophage polarization and potentially promotes hepatocarcinoma cell growth

In this article, we comment on the article by Huang et al. The urgent development of new therapeutic strategies targeting macrophage polarization is critical in the fight against liver cancer. Tumor-associated macrophages (TAMs), primarily of the M2 subtype, are instrumental in cellular communication within the tumor microenvironment and are influenced by various signaling pathways, including the wingless/integrated (Wnt) pathway. Activation of the Wnt signaling pathway is pivotal in promoting M2 TAMs polarization, which in turn can exacerbate hepatocarcinoma cell proliferation and migration. This manuscript emphasizes the burgeoning significance of the Wnt signaling pathway and M2 TAMs polarization in the pathogenesis and progression of liver cancer, highlighting the potential therapeutic benefits of inhibiting the Wnt pathway. Lastly, we point out areas in Huang et al's study that require further research, providing guidance and new directions for similar studies.

Dual Enzyme-Driven Cascade Reactions Modulate Immunosuppressive Tumor Microenvironment for Catalytic Therapy and Immune Activation

Lactate-enriched tumor microenvironment (TME) fosters an immunosuppressive milieu to hamper the functionality of tumor-associated macrophages (TAMs). However, tackling the immunosuppressive effects wrought by lactate accumulation is still a big challenge. Herein, we construct a dual enzyme-driven cascade reaction platform (ILH) with immunosuppressive TME modulation for photoacoustic (PA) imaging-guided catalytic therapy and immune activation. The ILH is composed of iridium (Ir) metallene nanozyme, lactate oxidase (LOx), and hyaluronic acid (HA). The combination of Ir nanozyme and LOx can not only efficiently consume lactate to reverse the immunosuppressive TME into an immunoreactive one by promoting the polarization of TAMs from the M2 to M1 phenotype, thus enhancing antitumor defense, but also alleviate tumor hypoxia as well as induce strong oxidative stress, thus triggering immunogenic cell death (ICD) and activating antitumor immunity. Furthermore, the photothermal performance of Ir nanozyme can strengthen the cascade catalytic ability and endow ILH with a PA response. Based on the changes in PA signals from endogenous molecules, three-dimensional multispectral PA imaging was utilized to track the process of cascade catalytic therapy in vivo. This work provides a nanoplatform for dual enzyme-driven cascade catalytic therapy and immune activation by regulating the immunosuppressive TME.

Disentangling the molecular mystery of tumour-microbiota interactions: Microbial metabolites

The profound impact of the microbiota on the initiation and progression of cancer has been a focus of attention. In recent years, many studies have shown that microbial metabolites serve as key hubs that connect the microbiome and cancer progression, but the underlying molecular mechanisms have not been fully elucidated. Multiple mechanisms that influence tumour development and therapy resistance, including disrupting cellular signalling pathways, triggering oxidative stress, inducing metabolic reprogramming and reshaping tumour immune microenvironment, are reviewed. Focusing on recent advancements in this field, this review also summarises the methodological framework of studies regarding microbial metabolites. In this review, we outline the current state of research on tumour-associated microbial metabolites and describe the challenges in future scientific research and clinical applications. KEY POINTS: Metabolites derived from both gut and intratumoural microbiota play important roles in cancer initiation and progression. The dual roles of microbial metabolites pose an obstacle for clinical translations. Absolute quantification and tracing techniques of microbial metabolites are essential for addressing the gaps in studies on microbial metabolites. Integrating microbial metabolomics with multi-omics transcends current research paradigms.

The regulatory role of mitotic catastrophe in hepatocellular carcinoma drug resistance mechanisms and its therapeutic potential

This review focuses on the role and underlying mechanisms of mitotic catastrophe (MC) in the regulation of drug resistance in hepatocellular carcinoma (HCC). HCC is one of the leading causes of cancer-related mortality worldwide, posing significant treatment challenges due to its high recurrence rates and drug resistance. Research suggests that MC, as a mechanism of cell death, plays a crucial role in enhancing the efficacy of HCC treatment by disrupting the replication and division mechanisms of tumor cells. The present review summarizes the molecular mechanisms of MC and its role in HCC drug resistance and explores the potential of combining MC with existing cancer therapies to improve treatment outcomes. Future research should focus on the in-depth elucidation of the molecular mechanisms of MC and its application in HCC therapy, providing new insights for the development of more effective treatments.

Inducing disulfidptosis in tumors:potential pathways and significance

Regulated cell death (RCD) is crucial for the elimination of abnormal cells. In recent years, strategies aimed at inducing RCD, particularly apoptosis, have become increasingly important in cancer therapy. However, the ability of tumor cells to evade apoptosis has led to treatment resistance and relapse, prompting extensive research into alternative death processes in cancer cells. A recent study identified a novel form of RCD known as disulfidptosis, which is linked to disulfide stress. Cancer cells import cystine from the extracellular environment via solute carrier family 7 member 11 (SLC7A11) and convert it to cysteine using nicotinamide adenine dinucleotide phosphate (NADPH). When NADPH is deficient or its utilization is impaired, cystine accumulates, leading to the formation of disulfide bonds in the actin cytoskeleton, triggering disulfidptosis. Disulfidptosis reveals a metabolic vulnerability in tumors, offering new insights into cancer therapy strategies. This review provides a detailed overview of the mechanisms underlying disulfidptosis, the current research progress, and limitations. It also highlights innovative strategies for inducing disulfidptosis and explores the potential of combining these approaches with traditional cancer therapies, particularly immunotherapy, to expedite clinical translation.

Taurine Inhibits Lung Metastasis in Triple-Negative Breast Cancer by Modulating Macrophage Polarization Through PTEN-PI3K/Akt/mTOR Pathway

SUMMARY

Taurine (Tau) has been found to inhibit triple-negative breast cancer (TNBC) invasion and metastasis. However, its effect on tumor-promoting macrophages and tumor suppressor macrophages in breast cancer progression remains unknown. In this study, we investigated the effects of Tau on macrophage polarization and its role in TNBC cell growth, invasion, and metastasis. We induced human THP-1 monocytes to differentiate into M2 macrophages through exogenous addition of interleukin-4. We used the TNBC cell lines MDA-MB-231 and BT-549 cultured in a conditioned medium from M2 macrophages to investigate the effect of Tau on tumor growth and invasion. We analyzed macrophage subset distribution, M1 and M2 macrophage-associated markers, and mRNA expression by quantitative polymerase chain reaction. We also detected the PTEN-PI3K/Akt/mTOR signaling pathway that mediates M1 macrophage to suppress tumor invasion using western blotting. Our results showed that Tau inhibits breast cancer metastasis to the lungs in vivo and cell invasion by altering the polarization of tumor-associated macrophage in vitro. In addition, Tau can up-regulate PTEN expression, suppress the PI3K-Akt signaling pathway, and promote the M1 polarization of macrophages, which ultimately inhibits the metastasis of TNBC cells. Our findings suggest that Tau inhibits the activation of the PI3K-Akt-mTOR signaling pathway by up-regulating PTEN , promotes the proportion of M1 macrophages in tumor-associated macrophage, and suppresses the invasion and metastasis of TNBC. This provides a potential therapeutic approach to influence cancer progression and metastasis.

Toxoplasma gondii macrophage migration inhibitory factor shows anti-Mycobacterium tuberculosis potential via AZIN1/STAT1 interaction

Mycobacterium tuberculosis (MTB) is a pathogenic bacterium, belonging to the family Mycobacteriaceae, that causes tuberculosis (TB). Toxoplasma gondii macrophage migration inhibitory factor (TgMIF), a protein homolog of macrophage migration inhibitory factor, has been explored for its potential to modulate immune responses during MTB infections. We observed that TgMIF that interacts with CD74, antizyme inhibitor 1 (AZIN1), and signal transducer and activator of transcription 1 (STAT1) modulates endocytosis, restoration of mitochondrial function, and macrophage polarization, respectively. These interactions promote therapeutic efficacy in mice infected with MTB, thereby presenting a potential route to host-directed therapy development. Furthermore, TgMIF, in combination with first-line TB drugs, significantly inhibited drug-resistant MTB strains, including multidrug-resistant TB. These results demonstrate that TgMIF is potentially a multifaceted therapeutic agent against TB, acting through immune modulation, enhancement of mitochondrial function, and dependent on STAT1 and AZIN1 pathways.

Cold and hot tumors: from molecular mechanisms to targeted therapy

Immunotherapy has made significant strides in cancer treatment, particularly through immune checkpoint blockade (ICB), which has shown notable clinical benefits across various tumor types. Despite the transformative impact of ICB treatment in cancer therapy, only a minority of patients exhibit a positive response to it. In patients with solid tumors, those who respond well to ICB treatment typically demonstrate an active immune profile referred to as the "hot" (immune-inflamed) phenotype. On the other hand, non-responsive patients may exhibit a distinct "cold" (immune-desert) phenotype, differing from the features of "hot" tumors. Additionally, there is a more nuanced "excluded" immune phenotype, positioned between the "cold" and "hot" categories, known as the immune "excluded" type. Effective differentiation between "cold" and "hot" tumors, and understanding tumor intrinsic factors, immune characteristics, TME, and external factors are critical for predicting tumor response and treatment results. It is widely accepted that ICB therapy exerts a more profound effect on "hot" tumors, with limited efficacy against "cold" or "altered" tumors, necessitating combinations with other therapeutic modalities to enhance immune cell infiltration into tumor tissue and convert "cold" or "altered" tumors into "hot" ones. Therefore, aligning with the traits of "cold" and "hot" tumors, this review systematically delineates the respective immune characteristics, influencing factors, and extensively discusses varied treatment approaches and drug targets based on "cold" and "hot" tumors to assess clinical efficacy.

Lactylome Analysis Unveils Lactylation-Dependent Mechanisms of Stemness Remodeling in the Liver Cancer Stem Cells

Lactate plays a critical role as an energy substrate, metabolite, and signaling molecule in hepatocellular carcinoma (HCC). Intracellular lactate-derived protein lysine lactylation (Kla) is identified as a contributor to the progression of HCC. Liver cancer stem cells (LCSCs) are believed to be the root cause of phenotypic and functional heterogeneity in HCC. However, the impact of Kla on the biological processes of LCSCs remains poorly understood. Here enhanced glycolytic metabolism, lactate accumulation, and elevated levels of lactylation are observed in LCSCs compared to HCC cells. H3K56la was found to be closely associated with tumourigenesis and stemness of LCSCs. Notably, a comprehensive examination of the lactylome and proteome of LCSCs and HCC cells identified the ALDOA K230/322 lactylation, which plays a critical role in promoting the stemness of LCSCs. Furthermore, this study demonstrated the tight binding between aldolase A (ALDOA) and dead box deconjugate enzyme 17 (DDX17), which is attenuated by ALDOA lactylation, ultimately enhancing the regulatory function of DDX17 in maintaining the stemness of LCSCs. This investigation highlights the significance of Kla in modulating the stemness of LCSCs and its impact on the progression of HCC. Targeting lactylation in LCSCs may offer a promising therapeutic approach for treating HCC.

Multifunctional vitamin D-incorporated PLGA scaffold with BMP/VEGF-overexpressed tonsil-derived MSC via CRISPR/Cas9 for bone tissue regeneration

Guiding endogenous regeneration of bone defects using biomaterials and regenerative medicine is considered an optimal strategy. One of the effective therapeutic approaches involves using transgene-expressed stem cells to treat tissue destruction and replace damaged parts. Among the various gene editing techniques for cells, clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) is considered as a promising method owing to the increasing therapeutic potential of cells by targeting specific sites. Herein, a vitamin D-incorporated poly(lactic-co-glycolic acid) (PLGA) scaffold with bone morphogenetic protein 2 (BMP2)/vascular endothelial growth factor (VEGF)-overexpressed tonsil-derived MSCs (ToMSCs) via CRISPR/Cas9 was introduced for bone tissue regeneration. The optimized seeding ratio of engineered ToMSCs on the scaffold demonstrated favorable immunomodulatory function, angiogenesis, and osteogenic activity in vitro. The multifunctional scaffold could potentially support stem cell in vivo and induce the transition from M1 to M2 macrophage with magnesium hydroxide and vitamin D. This study highlights the improved synergistic effect of a vitamin D-incorporated PLGA scaffold and a gene-edited ToMSCs for bone tissue engineering and regenerative medicine.

Extracellular vesicles for cancer therapy: potential, progress, and clinical challenges

Extracellular vesicles (EVs) play an important role in normal life activities and disease treatment. In recent years, there have been abundant relevant studies focusing on EVs for cancer therapy and showing good performance on tumor inhibition. To enhance the effectiveness of EVs, EV analogs have been developed. This review summarizes the classification, origin, production, purification, modification, drug loading and cancer treatment applications of EVs and their analogs. Also, the characteristics of technologies involved are analyzed, which provides the basis for the development and application of biogenic vesicle-based drug delivery platform for cancer therapy. Meanwhile, challenges in translating these vesicles into clinic, such as limited sources, lack of production standards, and insufficient targeting and effectiveness are discussed. With ongoing exploration and clinical studies, EV-based drugs will make great contributions to cancer therapy.

Innate immune cells in tumor microenvironment: A new frontier in cancer immunotherapy

Innate immune cells, crucial in resisting infections and initiating adaptive immunity, play diverse and significant roles in tumor development. These cells, including macrophages, granulocytes, dendritic cells (DCs), innate lymphoid cells, and innate-like T cells, are pivotal in the tumor microenvironment (TME). Innate immune cells are crucial components of the TME, based on which various immunotherapy strategies have been explored. Immunotherapy strategies, such as novel immune checkpoint inhibitors, STING/CD40 agonists, macrophage-based surface backpack anchoring, ex vivo polarization approaches, DC-based tumor vaccines, and CAR-engineered innate immune cells, aim to enhance their anti-tumor potential and counteract cancer-induced immunosuppression. The proximity of innate immune cells to tumor cells in the TME also makes them excellent drug carriers. In this review, we will first provide a systematic overview of innate immune cells within the TME and then discuss innate cell-based therapeutic strategies. Furthermore, the research obstacles and perspectives within the field will also be addressed.

Metabolic mediators: microbial-derived metabolites as key regulators of anti-tumor immunity, immunotherapy, and chemotherapy

The human microbiome has recently emerged as a focal point in cancer research, specifically in anti-tumor immunity, immunotherapy, and chemotherapy. This review explores microbial-derived metabolites, emphasizing their crucial roles in shaping fundamental aspects of cancer treatment. Metabolites such as short-chain fatty acids (SCFAs), Trimethylamine N-Oxide (TMAO), and Tryptophan Metabolites take the spotlight, underscoring their diverse origins and functions and their profound impact on the host immune system. The focus is on SCFAs' remarkable ability to modulate immune responses, reduce inflammation, and enhance anti-tumor immunity within the intricate tumor microenvironment (TME). The review critically evaluates TMAO, intricately tied to dietary choices and gut microbiota composition, assessing its implications for cancer susceptibility, progression, and immunosuppression. Additionally, the involvement of tryptophan and other amino acid metabolites in shaping immune responses is discussed, highlighting their influence on immune checkpoints, immunosuppression, and immunotherapy effectiveness. The examination extends to their dynamic interaction with chemotherapy, emphasizing the potential of microbial-derived metabolites to alter treatment protocols and optimize outcomes for cancer patients. A comprehensive understanding of their role in cancer therapy is attained by exploring their impacts on drug metabolism, therapeutic responses, and resistance development. In conclusion, this review underscores the pivotal contributions of microbial-derived metabolites in regulating anti-tumor immunity, immunotherapy responses, and chemotherapy outcomes. By illuminating the intricate interactions between these metabolites and cancer therapy, the article enhances our understanding of cancer biology, paving the way for the development of more effective treatment options in the ongoing battle against cancer.

Identification of novel M2 macrophage-related molecule ATP6V1E1 and its biological role in hepatocellular carcinoma based on machine learning algorithms

Hepatocellular carcinoma (HCC) remains the most prevalent form of primary liver cancer, characterized by late detection and suboptimal response to current therapies. The tumour microenvironment, especially the role of M2 macrophages, is pivotal in the progression and prognosis of HCC. We applied the machine learning algorithm-CIBERSORT, to quantify cellular compositions within the HCC TME, focusing on M2 macrophages. Gene expression profiles were analysed to identify key molecules, with ATP6V1E1 as a primary focus. We employed Gene Set Enrichment Analysis (GSEA) and Kaplan-Meier survival analysis to investigate the molecular pathways and prognostic significance of ATP6V1E1. A prognostic model was developed using multivariate Cox regression analysis based on ATP6V1E1-related molecules, and functional impacts were assessed through cell proliferation assays. M2 macrophages were the dominant cell type in the HCC TME, significantly correlating with adverse survival outcomes. ATP6V1E1 was robustly associated with advanced disease stages and poor prognostic features such as vascular invasion and elevated alpha-fetoprotein levels. GSEA linked high ATP6V1E1 expression to critical oncogenic pathways, including immunosuppression and angiogenesis, and reduced activity in metabolic processes like bile acid and fatty acid metabolism. The prognostic model stratified HCC patients into distinct risk categories, showing high predictive accuracy (1-year AUC = 0.775, 3-year AUC = 0.709 and 5-year AUC = 0.791). In vitro assays demonstrated that ATP6V1E1 knockdown markedly inhibited the proliferation of HCC cells. The study underscores the significance of M2 macrophages and ATP6V1E1 in HCC, highlighting their potential as therapeutic and prognostic targets.