Metabolism of immune cells in cancer

Single-cell sequencing in diffuse large B-cell lymphoma: C1qC is a potential tumor-promoting factor

BACKGROUND

Complement component 1q (C1q) is central to the classical complement pathway. High C1q expression has been linked to poor prognosis in patients with cancer. However, the precise mechanism via which C1q contributes to diffuse large B-cell lymphoma (DLBCL) is still unknown. We aimed to explore the potential mechanism by which C1qC promoting DLBCL.

METHODS

Using multiplex immunohistochemistry (mIHC) to identify immunocyte subgroups associated with prognosis in DLBCL tissues. Constructing a risk prediction model based on immunocytes using least absolute shrinkage and selection operator (LASSO) regression. Single-cell sequencing detects the expression level of C1qC in immunocytes in the DLBCL microenvironment. Using Wb and qPCR to detect markers of M2 macrophages after knocking down C1qC, and exploring the interactions between lymphoma cells and macrophages through co-culture. Analyzing clinical data from DLBCL patients to investigate the clinical significance of C1qC+ M2 macrophages. Lastly, using bioinformatics in conjunction with mIHC to elucidate the potential pro-tumor mechanism of C1qC.

RESULTS

First, we found T cell subtypes, neutrophils, and M2 macrophages are associated with prognosis. Subsequently, the risk model identified C1qC as a differential gene relevant to DLBCL prognosis. Furthermore, single-cell sequencing suggested high C1qC expression in M2 macrophages. The expression level of CD163 is significantly lower following siC1qC. Co-culture experiments have shown that M2 macrophages can promote the proliferation of tumor cells and reduce their drug sensitivity. Furthermore, as an independent predictive indicator, high expression of C1qC+ M2 macrophages is associated with poor prognosis in patients. Finally, a positive correlation between increased C1qC expression and immune checkpoints, as well as an increase in the infiltration of regulatory T cells (Tregs) and M2 macrophages.

CONCLUSIONS

C1qC offering new insights into pathogenesis and presenting a potential therapeutic target in DLBCL.

An immunotherapeutic hydrogel booster inhibits tumor recurrence and promotes wound healing for postoperative management of melanoma

Low tumor immunogenicity, immunosuppressive tumor microenvironment, and bacterial infections have emerged as significant challenges in postsurgical immunotherapy and skin regeneration for preventing melanoma recurrence. Herein, an immunotherapeutic hydrogel booster (GelMA-CJCNPs) was developed to prevent postoperative tumor recurrence and promote wound healing by incorporating ternary carrier-free nanoparticles (CJCNPs) containing chlorine e6 (Ce6), a BRD4 inhibitor (JQ1), and a glutaminase inhibitor (C968) into methacrylic anhydride-modified gelatin (GelMA) dressings. GelMA-CJCNPs reduced glutathione production by inhibiting glutamine metabolism, thereby preventing the destruction of reactive oxygen species generated by photodynamic therapy, which could amplify oxidative stress to induce severe cell death and enhance immunogenic cell death. In addition, GelMA-CJCNPs reduced M2-type tumor-associated macrophage polarization by blocking glutamine metabolism to reverse the immunosuppressive tumor microenvironment, recruiting more tumor-infiltrating T lymphocytes. GelMA-CJCNPs also downregulated IFN-γ-induced expression of programmed cell death ligand 1 to mitigate acquired immune resistance. Benefiting from the amplified systemic antitumor immunity, GelMA-CJCNPs markedly inhibited the growth of both primary and distant tumors. Moreover, GelMA-CJCNPs demonstrated satisfactory photodynamic antibacterial effects against Staphylococcus aureus infections, thereby promoting postsurgical wound healing. Hence, this immunotherapeutic hydrogel booster, as a facile and effective postoperative adjuvant, possesses a promising potential for inhibiting tumor recurrence and accelerating skin regeneration.

Inhibition of OXPHOS induces metabolic rewiring and reduces hypoxia in murine tumor models

Introduction

Tumor hypoxia is a feature of many solid malignancies and is known to cause radio resistance. In recent years it has become clear that hypoxic tumor regions also foster an immunosuppressive phenotype and are involved in immunotherapy resistance. It has been proposed that reducing the tumors' oxygen consumption will result in an increased oxygen concentration in the tissue and improve radio- and immunotherapy efficacy. The aim of this study is to investigate the metabolic rewiring of cancer cells by pharmacological attenuation of oxidative phosphorylation (OXPHOS) and subsequently reduce tumor hypoxia.

Material and methods

The metabolic effects of three OXPHOS inhibitors IACS-010759, atovaquone and metformin were explored by measuring oxygen consumption rate, extra cellular acidification rate, and [18F]FDG uptake in 2D and 3D cell culture. Tumor cell growth in 2D cell culture and hypoxia in 3D cell culture were analyzed by live cell imaging. Tumor hypoxia and [18F]FDG uptake in vivo following treatment with IACS-010759 was determined by immunohistochemistry and ex vivo biodistribution respectively.

Results

In vitro experiments show that tumor cell metabolism is heterogeneous between different models. Upon OXPHOS inhibition, metabolism shifts from oxygen consumption through OXPHOS towards glycolysis, indicated by increased acidification and glucose uptake. Inhibition of OXPHOS by IACS-010759 treatment reduced diffusion limited tumor hypoxia in both 3D cell culture and in vivo. Although immune cell presence was lower in hypoxic areas compared with normoxic areas, it is not altered following short term OXPHOS inhibition.

Discussion

These results show that inhibition of OXPHOS causes a metabolic shift from OXPHOS towards increased glycolysis in 2D and 3D cell culture. Moreover, inhibition of OXPHOS reduces diffusion limited hypoxia in 3D cell culture and murine tumor models. Reduced hypoxia by OXPHOS inhibition might enhance therapy efficacy in future studies. However, caution is warranted as systemic metabolic rewiring can cause adverse effects.

Exploring the Interplay of Diet, Obesity, Immune Function, and Cancer

This commentary provides an in-depth exploration of the intricate relationships among diet, obesity, immune function, and cancer, highlighting the potential role of dietary interventions as complementary therapies in cancer treatment. Multiple analyses underscore the importance of personalized dietary strategies in cancer management and identify opportunities for further research in this evolving field.

Macrophages and T cells in metabolic disorder-associated cancers

Cancer and metabolic disorders have emerged as major global health challenges, reaching epidemic levels in recent decades. Often viewed as separate issues, metabolic disorders are shown by mounting evidence to heighten cancer risk and incidence. The intricacies underlying this connection are still being unraveled and encompass a complex interplay between metabolites, cancer cells and immune cells within the tumour microenvironment (TME). Here, we outline the interplay between metabolic and immune cell dysfunction in the context of three highly prevalent metabolic disorders, namely obesity; two associated liver diseases, metabolic dysfunction-associated steatotic liver disease (MASLD) and metabolic dysfunction-associated steatohepatitis (MASH); and type 2 diabetes. We focus primarily on macrophages and T cells, the critical roles of which in dictating inflammatory response and immune surveillance in metabolic disorder-associated cancers are widely reported. Moreover, considering the ever-increasing number of patients prescribed with metabolism disorder-altering drugs and diets in recent years, we discuss how these therapies modulate systemic and local immune phenotypes, consequently impacting cancer malignancy. Collectively, unraveling the determinants of metabolic disorder-associated immune landscape and their role in fuelling cancer malignancy will provide a framework essential to therapeutically address these highly prevalent diseases.

Targeted Metabolic Profiling in Determining the Metabolic Heterogeneity in Human Biopsies of Different Grades of Glioma

Gliomas are intricate tumors with numerous metabolic and genetic abnormalities contributing to their aggressive phenotypes and poor prognoses. The study aims at identifying the key molecular metabolic as well as gene expressional variations that could be used to differentiate between different grades of glioma to obtain deeper insights the about metabolic status of glioma that may serve as good candidates of diagnosis in future. In the present study, the metabolomic profiling along with clinical and expressional analyses of glioma biopsies (n = 52; patients comprising both of benign and malignant lesions) was analyzed. The biopsies were subjected to gene/protein expressional analysis using RT-PCR and western blotting and also were subjected to metabolite analyses. The results of the gene/protein expressional analysis exhibited elevated levels of carnitine palmitoyltransferase, monoglyceride lipase, human phosphofructokinase, and isocitrate dehydrogenase in higher grades of glioma when compared to those of control. Our study suggested that the metabolites and gene/protein expressional levels were found to be discriminative among the grades of glioma. The study is deemed as a provider of deeper insights that are essential for differential therapeutic approaches that specifically target the dysregulated metabolome to the benefit of patients.

Reciprocal regulation of mTORC1 signaling and ribosomal biosynthesis determines cell cycle progression in activated T cells

Ribosomal biosynthesis in nucleoli is an energy-demanding process driven by all RNA polymerases and hundreds of auxiliary proteins. We investigated how this process is regulated in activated T lymphocytes by T cell receptor (TCR) signals and the multiprotein complexes mTORC1 and mTORC2, both of which contain the kinase mTOR. Deficiency in mTORC1 slowed the proliferation of T cells, with further delays in each consecutive division, an effect not seen with deficiency in mTORC2. mTORC1 signaling was stimulated by components of conventional TCR signaling, and, reciprocally, TCR sensitivity was decreased by mTORC1 inhibition. The substantial increase in the amount of RNA per cell induced by TCR activation was reduced by 50% by deficiency in mTORC1, but not in mTORC2 or in S6 kinases 1 and 2, which are activated downstream of mTORC1. RNA-seq data showed that mTORC1 deficiency reduced the abundance of all RNA biotypes, although rRNA processing was largely intact in activated T cells. Imaging cytometry with FISH probes for nascent pre-rRNA revealed that deletion of mTORC1, but not that of mTORC2, reduced the number and expansion of nucleolar sites of active transcription. Protein translation was consequently decreased by 50% in the absence of mTORC1. Inhibiting RNA polymerase I blocked not only proliferation but also mTORC1 signaling. Our data show that TCR signaling, mTORC1 activity, and ribosomal biosynthesis in the nucleolus regulate each other during biomass production in clonally expanding T cells.

Tumor-Selective Nano-Dispatcher Enforced Cancer Immunotherapeutic Effects via Regulating Lactate Metabolism and Activating Toll-Like Receptors

The development of tumors relies on lactate metabolic reprogramming to facilitate their unchecked growth and evade immune surveillance. This poses a significant challenge to the efficacy of antitumor immunity. To address this, a tumor-selective nano-dispatcher, PIMDQ/Syro-RNP, to enforce the immunotherapeutic effect through regulation of lactate metabolism and activation of toll-like receptors is developed. By using the tumor-targeting properties of c-RGD, the system can effectively deliver monocarboxylate transporters 4 (MCT4) inhibitor (Syro) to inhibit lactate efflux in tumor cells, leading to decreased lactate levels in the tumor microenvironment (TME) and increased accumulation within tumor cells. The reduction of lactate in TME will reduce the nutritional support for regulatory T cells (Tregs) and promote the effector function of T cells. The accumulation of lactate in tumor cells will lead to tumor death due to cellular acidosis. In addition, it will also reduce the uptake of glucose by tumor cells, reduce nutrient plunder, and further weaken the inhibition of T cell function. Furthermore, the pH-responsive release of Toll-like receptors (TLR) 7/8 agonist IMDQ within the TME activates dendritic cells (DCs) and promotes the infiltration of T cells. These findings offer a promising approach for enhancing tumor immune response through targeted metabolic interventions.

Targeting metabolism to enhance immunotherapy within tumor microenvironment

Cancer metabolic reprogramming has been considered an emerging hallmark in tumorigenesis and the antitumor immune response. Like cancer cells, immune cells within the tumor microenvironment or premetastatic niche also undergo extensive metabolic reprogramming, which profoundly impacts anti-tumor immune responses. Numerous evidence has illuminated that immunosuppressive TME and the metabolites released by tumor cells, including lactic acid, Prostaglandin E2 (PGE2), fatty acids (FAs), cholesterol, D-2-Hydroxyglutaric acid (2-HG), adenosine (ADO), and kynurenine (KYN) can contribute to CD8+ T cell dysfunction. Dynamic alterations of these metabolites between tumor cells and immune cells can similarly initiate metabolic competition in the TME, leading to nutrient deprivation and subsequent microenvironmental acidosis, which impedes immune response. This review summarizes the new landscape beyond the classical metabolic pathways in tumor cells, highlighting the pivotal role of metabolic disturbance in the immunosuppressive microenvironment, especially how nutrient deprivation in TME leads to metabolic reprogramming of CD8+ T cells. Likewise, it emphasizes the current therapeutic targets or strategies related to tumor metabolism and immune response, providing therapeutic benefits for tumor immunotherapy and drug development in the future. Cancer metabolic reprogramming has been considered an emerging hallmark in tumorigenesis and the antitumor immune response. Dynamic alterations of metabolites between tumor cells and immune cells initiate metabolic competition in the TME, leading to nutrient deprivation and subsequent microenvironmental acidosis, which impedes immune response.

Caulerpa chemnitzia polysaccharide exerts immunomodulatory activity in macrophages by mediating the succinate/PHD2/HIF-1α/IL-1β pathway

Algal polysaccharide is an important food functional factor with diverse bioactive and low toxicity. Previous studies have confirmed Caulerpa chemnitzia polysaccharides (CRVP) have immunomodulatory activity, but the immunomodulatory mechanism of CRVP in macrophages has not been thoroughly explored yet. In our research, we found that CRVP has outstanding immunomodulatory activity in macrophages, which is reflected in promoting cell proliferation, upregulating cytokines (IL-1β, IL-6, and TNF-α) expression, and increasing NO and ROS levels. Additionally, the result of joint analysis of untargeted metabolomics showed metabolism played a major role in the immunomodulatory of CRVP and suggested succinic acid was a key metabolite. Further verification indicated that the accumulation of succinic acid in macrophages after administered with CRVP, induced the down-regulation of prolyl hydroxylase domain 2 (PHD2) and up-regulation of hypoxia-inducible factor-1α (HIF-1α), thereby enhancing IL-1β expression. Together, the immunomodulatory activity of CRVP in macrophages via succinate/PHD2/HIF-1α/IL-1β pathway.

Advances in and prospects of immunotherapy for prostate cancer

Immunotherapy has shown promising therapeutic effects in hematological malignancies and certain solid tumors and has emerged as a critical and highly potential treatment modality for cancer. However, prostate cancer falls under the category of immune-resistant cold tumors, for which immunotherapy exhibits limited efficacy in patients with solid tumors. Thus, it is important to gain a deeper understanding of the tumor microenvironment in prostate cancer to facilitate immune system activation and overcome immune suppression to advance immunotherapy for prostate cancer. In this review, we discuss the immunosuppressive microenvironment of prostate cancer, which is characterized by the presence of few tumor-infiltrating lymphocytes, abundant immunosuppressive cells, low immunogenicity, and a noninflammatory phenotype, which significantly influences the efficacy of immunotherapy for prostate cancer. Immunotherapy is mainly achieved by activating the host immune system and overcoming immunosuppression. In this regard, we summarize the therapeutic advances in immune checkpoint blockade, immunogenic cell death, reversal of the immunosuppressive tumor microenvironment, tumor vaccines, immune adjuvants, chimeric antigen receptor T-cell therapy, and overcoming penetration barriers in prostate cancer, with the aim of providing novel research insights and approaches to enhance the effectiveness of immunotherapy for prostate cancer.

SNX4 Is Correlated With Immune Infiltration and Prognosis in Clear Cell Renal Cell Carcinoma

Background

Clear cell renal cell carcinoma (ccRCC) is known as the most common and malignant histologic subtype of renal carcinoma. Sorting nexin 4 (SNX4) plays a regulatory role in recycling from endosomes to the plasma membrane and promotes autophagosome assembly and transport, which may exert the cancerous growth and progression. This study aimed to assess the biological role of SNX4 in ccRCC and their clinical association via public biological data platforms combined with experimental verification.

Methods

In our study, we analyzed the mRNA and protein expression of SNX4 in ccRCC under different clinicopathological characteristics through The Cancer Genome Atlas (TCGA), Human Protein Atlas (HPA) and Clinical Proteomic Tumor Analysis Consortium (CPTAC) databases. We used the Gene Expression Profiling Interactive Analysis (GEPIA) platform to conduct the survival analysis and figure out the immune cell infiltration level under different expression levels of SNX4 combined with Tumor Immune Estimation Resource (TIMER) database. Furthermore, we predicted competing endogenous RNA (ceRNA) regulatory network using TargetScan, miRDB, starBase and miRTarBase online databases. We totally collected six paired ccRCC tissues and adjacent tissues and applied quantitative real-time polymerase chain reaction (qRT-PCR) and western blot (WB) to detect the expression of SNX4 in the collected clinical specimens.

Results

The mRNA and protein expression level of SNX4 was significantly lower in ccRCC than those in normal tissues. The results proposed that lower SNX4 was expressed in patients with higher histologic grade and in male patients. Kaplan-Meier analysis demonstrated that lower mRNA expression level of SNX4 was correlated with poorer prognosis. SNX4 had positive correlation with immune cell infiltrating levels and programmed cell death-ligand 1 (PD-L1) expression. Furthermore, we constructed the SNX4/miR-221-3p/miR-222-3p/DHRS4-AS1 axis, which may be the underlying ceRNA interaction network. Finally, we verified the reduced expression of SNX4 in ccRCC by qRT-PCR and WB.

Conclusion

The expression of SNX4 in ccRCC was lower than adjacent tissues and its downregulated expression was associated with poor prognosis of ccRCC patients. SNX4 may exert critical roles in the tumorigenesis, development and migration of ccRCC via various mechanisms.

Valence-Transforming O2-Depleting Nano-Assembly Enable In Situ Tumor Depositional Embolization

Abnormal metabolism and blood supply/O2 imbalance in tumor cells affect drug transport delivery and increase the difficulty of tumor treatment. Controlling tumor growth by inhibiting tumor cell metabolism and regulating progressive embolization in the tumor region provides an innovative basis for constructing tumor therapeutic models. A highly biocompatible and efficient O2-depleting agent has been investigated to enable in situ precipitation and embolization within the tumor microenvironment. In situ deformation embolizer, Fe-GA@CaCO3 nano-assembly (GA: gallic acid), can convert into the large granular size embolization components of Fe(III) precipitates and affluent Ca2+ within the tumor microenvironment. In situ progressive O2 depletion produces Fe(III) precipitates that embolize tumor regions, isolating O2 and nutrients by blocking supply. Meanwhile, affluent Ca2+ acts on the intracellular, causing mitochondrial dysfunction through calcium overload and contributing to irreversible tumor cell damage. Both internal and external routes work synergistically to produce precise functional inhibition of tumors from the inside out, simultaneously responding to both intracellular and the corresponding tumor regions, providing an innovative solution for anti-tumor therapy.

Nucleolin malonylation as a nuclear-cytosol signal exchange mechanism to drive cell proliferation in Hepatocarcinoma by enhancing AKT translation

Cancer cells undergo metabolic reprogramming that is intricately linked to malignancy. Protein acylations are especially responsive to metabolic changes, influencing signal transduction pathways and fostering cell proliferation. However, as a novel type of acylations, the involvement of malonylation in cancer remains poorly understood. In this study, we observed a significant reduction in malonyl-CoA levels in hepatocellular carcinoma (HCC), which correlated with a global decrease in malonylation. Subsequent nuclear malonylome analysis unveiled nucleolin (NCL) malonylation, which was notably enhanced in HCC biopsies. we demonstrated that NCL undergoes malonylation at lysine residues 124 and 398. This modification triggers the translocation of NCL from the nucleolus to nucleoplasm and cytoplasm, binding to AKT mRNA, and promoting AKT translation in HCC. Silencing AKT expression markedly attenuated HCC cell proliferation driven by NCL malonylation. These findings collectively highlight nuclear signaling in modulating AKT expression, suggesting NCL malonylation as a novel mechanism through which cancer cells drive cell proliferation.

Causal effects and metabolites mediators between immune cell and risk of colorectal cancer: a Mendelian randomization study

Objective

The involvement of immune cells in colorectal cancer (CRC) and their interplay with metabolic disorders are yet to be fully elucidated. This study examines how peripheral immune cells, inferred genetically, affect CRC and investigates the intermediary roles of metabolites.

Methods

We employed a two-sample bidirectional Mendelian randomization (MR) approach to assess the causal influence of immune cells on CRC. Additionally, a two-step MR strategy was utilized to pinpoint potential metabolites that mediate this effect. Our analysis incorporated data from genome-wide association studies (GWAS), involving 731 immune cell types, 1,400 metabolites, and CRC outcomes. The primary method of analysis was randomized inverse variance weighting (IVW), supported by MR-Egger, weighted median, simple mode, and weighted mode analyses. Sensitivity checks were conducted using Cochran's Q test, MR-PRESSO test, MR-Egger regression intercept, and leave-one-out analysis.

Results

The study identified 23 immune cell types and 17 metabolites that are causally linked to CRC. Our mediation analysis highlighted that nine metabolites act as intermediaries in the relationship between nine specific immune cells and CRC risk. Notably, The ratios of Adenosine 5'-monophosphate (AMP) to aspartate and Retinol (Vitamin A) to linoleoyl-arachidonoyl-glycerol (18:2 to 20:4) were found to concurrently mediate the promoting effects of Myeloid DC %DC and BAFF-R on B cells in colorectal cancer (CRC). Moreover, iminodiacetate (IDA) was found to mediate the protective effect of CD14+ CD16- monocytes on CRC, contributing 11.8% to this mediation. In contrast, IDA was also seen to decrease the protective effect of IgD+ CD38br %B cells on CRC risk, with a mediation effect proportion of -10.4%.

Conclusion

This study delineates a complex network involving immune cells, metabolites, and CRC, suggesting a multifaceted pathophysiological interaction. The identified causal links and mediation pathways underscore potential therapeutic targets, providing a foundation for interventions aimed at modulating immune responses to manage CRC.

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.

HIF1A-AS2 promotes the metabolic reprogramming and progression of colorectal cancer via miR-141-3p/FOXC1 axis

lncRNA can regulate tumorigenesis development and distant metastasis of colorectal cancer (CRC). However, the detailed molecular mechanisms are still largely unknown. Using RNA-sequencing data, RT-qPCR, and FISH assay, we found that HIF1A-AS2 was upregulated in CRC tissues and associated with poor prognosis. Functional experiments were performed to determine the roles of HIF1A-AS2 in tumor progression and we found that HIF1A-AS2 can promote the proliferation, metastasis, and aerobic glycolysis of CRC cells. Mechanistically, HIF1A-AS2 can promote FOXC1 expression by sponging miR-141-3p. SP1 can transcriptionally activate HIF1A-AS2. Further, HIF1A-AS2 can be packaged into exosomes and promote the malignant phenotype of recipient tumor cells. Taken together, we discovered that SP1-induced HIF1A-AS2 can promote the metabolic reprogramming and progression of CRC via miR-141-3p/FOXC1 axis. HIF1A-AS2 is a promising diagnostic marker and treatment target in CRC.

Cancer cell metabolism and antitumour immunity

Accumulating evidence suggests that metabolic rewiring in malignant cells supports tumour progression not only by providing cancer cells with increased proliferative potential and an improved ability to adapt to adverse microenvironmental conditions but also by favouring the evasion of natural and therapy-driven antitumour immune responses. Here, we review cancer cell-intrinsic and cancer cell-extrinsic mechanisms through which alterations of metabolism in malignant cells interfere with innate and adaptive immune functions in support of accelerated disease progression. Further, we discuss the potential of targeting such alterations to enhance anticancer immunity for therapeutic purposes.

A review of the neurobehavioural, physiological, and reproductive toxicity of microplastics in fishes

Microplastics (MPs) have emerged as widespread environmental pollutants, causing significant threats to aquatic ecosystems and organisms. This review examines the toxic effects of MPs on fishes, with a focus on neurobehavioural, physiological, and reproductive impacts, as well as the underlying mechanisms of toxicity. Evidence indicates that MPs induce a range of neurobehavioural abnormalities in fishes, affecting social interactions and cognitive functions. Altered neurotransmitter levels are identified as a key mechanism driving behavioural alterations following MP exposure. Physiological abnormalities in fishes exposed to MPs are also reported, including neurotoxicity, immunotoxicity, and oxidative stress. These physiological disruptions can compromise the individual health of aquatic organisms. Furthermore, reproductive abnormalities linked to MP exposure are discussed, with a particular emphasis on disruptions in endocrine signaling pathways. These disruptions can impair reproductive success in fish species, impacting population numbers. Here we explore the critical role of endocrine disruptions in mediating reproductive effects after exposure to MPs, focusing primarily on the hypothalamic-pituitary-gonadal axis. Our review highlights the urgent need for interdisciplinary research efforts aimed at elucidating the full extent of MP toxicity and its implications for aquatic ecosystems. Lastly, we identify knowledge gaps for future research, including investigations into the transgenerational impacts, if any, of MP exposure and quantifying synergetic/antagonistic effects of MPs with other environmental pollutants. This expanded knowledge regarding the potential risks of MPs to aquatic wildlife is expected to aid policymakers in developing mitigation strategies to protect aquatic species.

Energy-storing DNA-based hydrogel remodels tumor microenvironments for laser-free photodynamic immunotherapy

Photodynamic therapy (PDT) is a promising modality for cancer treatment. However, limited tissue penetration of external radiation and complicated tumor microenvironments (TMEs) restrict the antitumor efficiency of PDT. Herein, we report an energy-storing DNA-based hydrogel, which enables tumor-selective PDT without external radiation and regulates TMEs to achieve boosted PDT-mediated tumor immunotherapy. The system is constructed with two ultralong single-stranded DNA chains, which programmed partial complementary sequences and repeated G-quadruplex forming AS1411 aptamer for photosensitizer loading via hydrophobic interactions and π-π stacking. Then, energy-storing persistent luminescent nanoparticles are incorporated to sensitize PDT selectively at tumor site without external irradiation, generating tumor antigen to agitate antitumor immune response. The system catalytically generates O2 to alleviate hypoxia and releases inhibitors to reverse the IDO-related immunosuppression, synergistically remodeling the TMEs. In the mouse model of breast cancer, this hydrogel shows a remarkable tumor suppression rate of 78.3 %. Our study represents a new paradigm of photodynamic immunotherapy against cancer by combining laser-free fashion and TMEs remodeling.

Metabolic crosstalk: Extracellular ATP and the tumor microenvironment in cancer progression and therapy

Adenosine 5'-triphosphate (ATP) is a vital element in energy information. It plays a critical role in transmitting signals inside the body, which is necessary for controlling the life activities of all cells, including tumor cells [1]. Its significance extends from intracellular signaling pathways to tumor regression. Purinergic signaling, a form of extracellular paracrine signaling, relies on purine nucleotides. Extracellular ectonucleotidases convert these purine nucleotides to their respective di and mono-phosphate nucleoside forms, contributing significantly to immune biology, cancer biology, and inflammation studies. ATP functions as a mighty damage-linked molecular pattern when released outside the cell, accumulating in inflammatory areas. In the tumor microenvironment (TME), purinergic receptors such as ATP-gated ion channels P2X1-5 and G protein-coupled receptors (GPCR) (P2Y) interact with ATP and other nucleotides, influencing diverse immune cell activities. CD39 and CD73-mediated extracellular ATP degradation contributes to immunosuppression by diminishing ATP-dependent activation and generating adenosine (ADO), potentially hindering antitumor immunity and promoting tumor development. Unraveling the complexities of extracellular ATP (e-ATP) and ADO effects on the TME poses challenges in identifying optimal treatment targets, yet ongoing investigations aim to devise strategies combating e-ATP/ADO-induced immunosuppression, ultimately enhancing anti-tumor immunity. This review explores e-ATP metabolism, its purinergic signaling, and therapeutic strategies targeting associated receptors and enzymes.

Clinical signature and associated immune metabolism of NLRP1 in pan-cancer

Inflammations have been linked to tumours, suggesting a potential association between NLRP1 and cancer. Nevertheless, a systematic assessment of NLRP1's role across various cancer types currently absent. A comprehensive bioinformatic analysis was conducted to determine whether NLRP1 exhibits prognostic relevance linked to immune metabolism across various cancers. The study leveraged data from the TCGA and GTEx databases to explore the clinical significance, metabolic features, and immunological characteristics of NLRP1, employing various tools such as R, GEPIA, STRING and TISIDB. NLRP1 exhibited differential expression patterns across various cancers, with elevated expression correlating with a more favourable prognosis in lung adenocarcinoma (LUAD) and pancreatic adenocarcinoma (PAAD). Downregulation of NLRP1 reduced tumour metabolic activity in LUAD. Moreover, the mutational signature of NLRP1 was linked to a favourable prognosis. Interestingly, high NLRP1 expression inversely correlated with tumour stemness while positively correlating with tumour immune infiltration in various cancers including LUAD and PAAD. Through extensive big data analysis, we delved into the role of NLRP1 across various tumour types, constructing a comprehensive role map of its involvement in pan-cancer scenarios. Our findings highlight the potential of NLRP1 as a promising therapeutic target specifically in LUAD and PAAD.

Prognostic Signature in Osteosarcoma Based on Amino Acid Metabolism-Associated Genes

Background: Osteosarcoma (OS) is undeniably a formidable bone malignancy characterized by a scarcity of effective treatment options. Reprogramming of amino acid (AA) metabolism has been associated with OS development. The present study was designed to identify metabolism-associated genes (MAGs) that are differentially expressed in OS and to construct a MAG-based prognostic risk signature for this disease. Methods: Expression profiles and clinicopathological data were downloaded from Gene Expression Omnibus (GEO) and UCSC Xena databases. A set of AA MAGs was obtained from the MSigDB database. Differentially expressed genes (DEGs) in GEO dataset were identified using "limma." Prognostic MAGs from UCSC Xena database were determined through univariate Cox regression and used in the prognostic signature development. This signature was validated using another dataset from GEO database. Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, single sample gene set enrichment analysis, and GDSC2 analyses were performed to explore the biological functions of the MAGs. A MAG-based nomogram was established to predict 1-, 3-, and 5-year survival. Real-time quantitative polymerase chain reaction, Western blot, and immunohistochemical staining confirmed the expression of MAGs in primary OS and paired adjacent normal tissues. Results: A total of 790 DEGs and 62 prognostic MAGs were identified. A MAG-based signature was constructed based on four MAGs: PIPOX, PSMC2, SMOX, and PSAT1. The prognostic value of this signature was successfully validated, with areas under the receiver operating characteristic curves for 1-, 3-, and 5-year survival of 0.714, 0.719, and 0.715, respectively. This MAG-based signature was correlated with the infiltration of CD56dim natural killer cells and resistance to several antiangiogenic agents. The nomogram was accurate in predictions, with a C-index of 0.77. The expression of MAGs verified by experiment was consistent with the trends observed in GEO database. Conclusion: Four AA MAGs were prognostic of survival in OS patients. This MAG-based signature has the potential to offer valuable insights into the development of treatments for OS.

Enhanced Osteosarcoma Immunotherapy via CaCO3 Nanoparticles: Remodeling Tumor Acidic and Immune Microenvironment for Photodynamic Therapy

Osteosarcoma (OS) is a "cold" tumor enriched in noninflammatory M2 phenotype tumor-associated macrophages (TAMs), which limits the efficacy of immunotherapy. The acidic tumor microenvironment (TME), generated by factors such as excess hydrogen (H+) ions and high lactate levels, activates immunosuppressive cells, further promoting a suppressive tumor immune microenvironment (TIME). Therefore, a multitarget synergistic combination strategy that neutralizes the acidic TME and reprograms TAMs can be beneficial for OS therapy. Here, a calcium carbonate (CaCO3)/polydopamine (PDA)-based nanosystem (A-NPs@(SHK+Ce6)) is developed. CaCO3 nanoparticles are used to neutralize H+ ions and alleviate the suppressive TIME, and the loaded SHK not only synergizes with photodynamic therapy (PDT) but also inhibits lactate production, further reversing the acidic TME and repolarizing TAMs to consequently lead to enhanced PDT-induced tumor suppression and comprehensive beneficial effects on antitumor immune responses. Importantly, A-NPs@(SHK+Ce6), in combination with programmed cell death protein 1 (PD-1) checkpoint blockade, shows a remarkable ability to eliminate distant tumors and promote long-term immune memory function to protect against rechallenged tumors. This work presents a novel multiple-component combination strategy that coregulates the acidic TME and TAM polarization to reprogram the TIME.

Activation and antitumor immunity of CD8+ T cells are supported by the glucose transporter GLUT10 and disrupted by lactic acid

CD8+ T cell activation leads to the rapid proliferation and differentiation of effector T cells (Teffs), which mediate antitumor immunity. Although aerobic glycolysis is preferentially activated in CD8+ Teffs, the mechanisms that regulate CD8+ T cell glucose uptake in the low-glucose and acidic tumor microenvironment (TME) remain poorly understood. Here, we report that the abundance of the glucose transporter GLUT10 is increased during CD8+ T cell activation and antitumor immunity. Specifically, GLUT10 deficiency inhibited glucose uptake, glycolysis, and antitumor efficiency of tumor-infiltrating CD8+ T cells. Supplementation with glucose alone was insufficient to rescue the antitumor function and glucose uptake of CD8+ T cells in the TME. By analyzing tumor environmental metabolites, we found that high concentrations of lactic acid reduced the glucose uptake, activation, and antitumor effects of CD8+ T cells by directly binding to GLUT10's intracellular motif. Disrupting the interaction of lactic acid and GLUT10 by the mimic peptide PG10.3 facilitated CD8+ T cell glucose utilization, proliferation, and antitumor functions. The combination of PG10.3 and GLUT1 inhibition or anti-programmed cell death 1 antibody treatment showed synergistic antitumor effects. Together, our data indicate that GLUT10 is selectively required for glucose uptake of CD8+ T cells and identify that TME accumulated lactic acid inhibits CD8+ T cell effector function by directly binding to GLUT10 and reducing its glucose transport capacity. Last, our study suggests disrupting lactate-GLUT10 binding as a promising therapeutic strategy to enhance CD8+ T cell-mediated antitumor effects.

Multifunctional Bioactivity Electrospinning Nanofibers Encapsulating Emodin Provides a Potential Postoperative Management Strategy for Skin Cancer

Skin cancer is threatening more and more people's health; its postoperative recurrence and wound infection are still critical challenges. Therefore, specialty wound dressings with multifunctional bioactivity are urgently desired. Emodin is a natural anthraquinone compound that has anti-cancer and anti-bacterial properties. Herein, we fabricated coaxial electrospinning nanofibers loaded with emodin to exploit a multifunctional wound dressing for skin cancer postoperative management, which encapsulated emodin in a polyvinylpyrrolidone core layer, combined with chitosan-polycaprolactone as a shell layer. The nanofibers were characterized via morphology, physicochemical nature, drug load efficiency, pH-dependent drug release profiles, and biocompatibility. Meanwhile, the anti-cancer and anti-bacterial effects were evaluated in vitro. The emodin-loaded nanofibers exhibited smooth surfaces with a relatively uniform diameter distribution and a clear shell-core structure; remarkably, emodin was evenly dispersed in the nanofibers with significantly enhanced dissolution of emodin. Furthermore, they not only display good wettability, high emodin entrapment efficiency, and biphasic release profile but also present superior biocompatibility and anti-cancer properties by increasing the levels of MDA and ROS in A-375 and HSC-1 cells via apoptosis-related pathway, and long-term anti-bacterial effects in a dose-independent manner. The findings indicate that the emodin-loaded nanofiber wound dressing can provide a potential treatment strategy for skin cancer postoperative management.

Tumor microenvironment induced switch to mitochondrial metabolism promotes suppressive functions in immune cells

Understanding the intricacies of the metabolic phenotype in immune cells and its plasticity within the tumor microenvironment is pivotal in understanding the pathology and prognosis of cancer. Unfavorable conditions and cellular stress in the tumor microenvironment (TME) exert a profound impact on cellular functions in immune cells, thereby influencing both tumor progression and immune responses. Elevated AMP:ATP ratio, a consequence of limited glucose levels, activate AMP-activated protein kinase (AMPK) while concurrently repressing the activity of mechanistic target of rapamycin (mTOR) and hypoxia-inducible factor 1-alpha (HIF-1α). The intricate balance between AMPK, mTOR, and HIF-1α activities defines the metabolic phenotype of immune cells in the TME. These Changes in metabolic phenotype are strongly associated with immune cell functions and play a crucial role in creating a milieu conducive to tumor progression. Insufficiency of nutrient and oxygen supply leads to a metabolic shift in immune cells characterized by a decrease in glycolysis and an increase in oxidative phosphorylation (OXPHOS) and fatty acid oxidation (FAO) rates. In most cases, this shift in metabolism is accompanied by a compromise in the effector functions of these immune cells. This metabolic adaptation prompts immune cells to turn down their effector functions, entering a quiescent or immunosuppressive state that may support tumor growth. This article discusses how tumor microenvironment alters the metabolism in immune cells leading to their tolerance and tumor progression, with emphasis on mitochondrial metabolism (OXPHOS and FAO).

The extracellular matrix integrates mitochondrial homeostasis

Cellular homeostasis is intricately influenced by stimuli from the microenvironment, including signaling molecules, metabolites, and pathogens. Functioning as a signaling hub within the cell, mitochondria integrate information from various intracellular compartments to regulate cellular signaling and metabolism. Multiple studies have shown that mitochondria may respond to various extracellular signaling events. However, it is less clear how changes in the extracellular matrix (ECM) can impact mitochondrial homeostasis to regulate animal physiology. We find that ECM remodeling alters mitochondrial homeostasis in an evolutionarily conserved manner. Mechanistically, ECM remodeling triggers a TGF-β response to induce mitochondrial fission and the unfolded protein response of the mitochondria (UPRMT). At the organismal level, ECM remodeling promotes defense of animals against pathogens through enhanced mitochondrial stress responses. We postulate that this ECM-mitochondria crosstalk represents an ancient immune pathway, which detects infection- or mechanical-stress-induced ECM damage, thereby initiating adaptive mitochondria-based immune and metabolic responses.

Targeting gut microbiota for immunotherapy of diseases

With advances in next-generation sequencing technology, there is growing evidence that the gut microbiome plays a key role in the host's innate and adaptive immune system. Gut microbes and their metabolites directly or indirectly regulate host immune cells. Crucially, dysregulation of the gut microbiota is often associated with many immune system diseases. In turn, microbes modulate disease immunotherapy. Data from preclinical to clinical studies suggest that the gut microbiota may influence the effectiveness of tumor immunotherapy, particularly immune checkpoint inhibitors (ICIs). In addition, the most critical issue now is a COVID-19 vaccine that generates strong and durable immunity. A growing number of clinical studies confirm the potential of gut microbes to enhance the efficacy of COVID-19 vaccines. However, it is still unclear how gut bacteria interact with immune cells and what treatments are based on gut microbes. Here, we outline recent advances in the effects and mechanisms of the gut microbiota and its metabolites (tryptophan metabolites, bile acids, short-chain fatty acids, and inosine) on different immune cells (dendritic cells, CD4+T cells, and macrophages). It also highlights innovative intervention strategies and clinical trials of microbiota-based checkpoint blocking therapies for tumor immunity, and ongoing efforts to maintain the long-term immunogenicity of COVID-19 vaccines. Finally, the challenges to be overcome in this area are discussed. These provide an important basis for further research and clinical translation of gut microbiota.

Discovery of a potential bladder cancer inhibitor CHNQD-01281 by regulating EGFR and promoting infiltration of cytotoxic T cells

As one of the common malignancies that threaten human life, bladder cancer occurs frequently with a high mortality rate in the world, due to its invasion, recurrence and drug resistance. Natural products from marine microorganisms are becoming the hotspots in discovery of new candidate drug entities, especially in the area of cancer. Brefeldin A (BFA) is a natural Arf-GEFs inhibitor, but due to the low aqueous solubility, strong toxicity, and poor bioavailability, it is urgent to conduct structural optimization research. Herein, a new BFA pyridine acrylate derivative CHNQD-01281 with improved solubility was prepared and found to exert moderate to strong antiproliferative activity on a variety of human cancer cell lines. It was noteworthy that CHNQD-01281 was most sensitive to two bladder cancer cell lines T24 and J82 (IC50 = 0.079 and 0.081 μmol/L) with high selectivity index (SI = 14.68 and 14.32), suggesting a superior safety to BFA. In vivo studies revealed that CHNQD-01281 remarkably suppressed tumor growth in a T24 nude mice xenograft model (TGI = 52.63%) and prolonged the survival time (ILS = 68.16%) in an MB49 allogeneic mouse model via inducing infiltration of cytotoxic T cells. Further mechanism exploration indicated that CHNQD-01281 regulated both EGFR/PI3K/AKT and EGFR/ERK pathways and mediated the chemotactic effect of chemokines on immune effector cells. Overall, CHNQD-01281 may serve as a potential therapeutic agent for bladder cancer through multiple mechanisms.

Supplementary Information

The online version contains supplementary material available at 10.1007/s42995-024-00246-w.

Focusing on the Immune Cells: Recent Advances in Immunotherapy for Biliary Tract Cancer

Biliary tract cancer (BTC) represents a challenging malignancy characterized by aggressive behavior, high relapse rates, and poor prognosis. In recent years, immunotherapy has revolutionized the treatment landscape for various cancers, but its efficacy in BTC remains limited. This article provides a comprehensive overview of the advances in preclinical and clinical studies of immunotherapy for BTC. We explore the potential of immune checkpoint inhibitors in reshaping the management of BTC. Despite disappointing results thus far, ongoing clinical trials are investigating the combination of immunotherapy with other treatment modalities. Furthermore, research on the tumor microenvironment has unveiled novel targets for immunotherapeutic interventions. By understanding the current state of immunotherapy in BTC and highlighting future directions, this article aims to fuel further exploration and ultimately improve patient outcomes in this challenging disease.

Involvement of tumor immune microenvironment metabolic reprogramming in colorectal cancer progression, immune escape, and response to immunotherapy

Metabolic reprogramming is a k`ey hallmark of tumors, developed in response to hypoxia and nutrient deficiency during tumor progression. In both cancer and immune cells, there is a metabolic shift from oxidative phosphorylation (OXPHOS) to aerobic glycolysis, also known as the Warburg effect, which then leads to lactate acidification, increased lipid synthesis, and glutaminolysis. This reprogramming facilitates tumor immune evasion and, within the tumor microenvironment (TME), cancer and immune cells collaborate to create a suppressive tumor immune microenvironment (TIME). The growing interest in the metabolic reprogramming of the TME, particularly its significance in colorectal cancer (CRC)-one of the most prevalent cancers-has prompted us to explore this topic. CRC exhibits abnormal glycolysis, glutaminolysis, and increased lipid synthesis. Acidosis in CRC cells hampers the activity of anti-tumor immune cells and inhibits the phagocytosis of tumor-associated macrophages (TAMs), while nutrient deficiency promotes the development of regulatory T cells (Tregs) and M2-like macrophages. In CRC cells, activation of G-protein coupled receptor 81 (GPR81) signaling leads to overexpression of programmed death-ligand 1 (PD-L1) and reduces the antigen presentation capability of dendritic cells. Moreover, the genetic and epigenetic cell phenotype, along with the microbiota, significantly influence CRC metabolic reprogramming. Activating RAS mutations and overexpression of epidermal growth factor receptor (EGFR) occur in approximately 50% and 80% of patients, respectively, stimulating glycolysis and increasing levels of hypoxia-inducible factor 1 alpha (HIF-1α) and MYC proteins. Certain bacteria produce short-chain fatty acids (SCFAs), which activate CD8+ cells and genes involved in antigen processing and presentation, while other mechanisms support pro-tumor activities. The use of immune checkpoint inhibitors (ICIs) in selected CRC patients has shown promise, and the combination of these with drugs that inhibit aerobic glycolysis is currently being intensively researched to enhance the efficacy of immunotherapy.

Glutamine metabolic competition drives immunosuppressive reprogramming of intratumour GPR109A+ myeloid cells to promote liver cancer progression

OBJECTIVE

The metabolic characteristics of liver cancer drive considerable hurdles to immune cells function and cancer immunotherapy. However, how metabolic reprograming in the tumour microenvironment impairs the antitumour immune response remains unclear.

DESIGN

Human samples and multiple murine models were employed to evaluate the correlation between GPR109A and liver cancer progression. GPR109A knockout mice, immune cells depletion and primary cell coculture models were used to determine the regulation of GPR109A on tumour microenvironment and identify the underlying mechanism responsible for the formation of intratumour GPR109A+myeloid cells.

RESULTS

We demonstrate that glutamine shortage in liver cancer tumour microenvironment drives an immunosuppressive GPR109A+myeloid cells infiltration, leading to the evasion of immune surveillance. Blockade of GPR109A decreases G-MDSCs and M2-like TAMs abundance to trigger the antitumour responses of CD8+ T cells and further improves the immunotherapy efficacy against liver cancer. Mechanistically, tumour cells and tumour-infiltrated myeloid cells compete for glutamine uptake via the transporter SLC1A5 to control antitumour immunity, which disrupts the endoplasmic reticulum (ER) homoeostasis and induces unfolded protein response of myeloid cells to promote GPR109A expression through IRE1α/XBP1 pathway. The restriction of glutamine uptake in liver cancer cells, as well as the blockade of IRE1α/XBP1 signalling or glutamine supplementation, can eliminate the immunosuppressive effects of GPR109A+ myeloid cells and slow down tumour progression.

CONCLUSION

Our findings identify the immunometabolic crosstalk between liver cancer cells and myeloid cells facilitates tumour progression via a glutamine metabolism/ER stress/GPR109A axis, suggesting that GPR109A can be exploited as an immunometabolic checkpoint and putative target for cancer treatment.

Metabolic reprogramming in hepatocellular carcinoma: a bibliometric and visualized study from 2011 to 2023

Background and aims

Metabolic reprogramming has been found to be a typical feature of tumors. Hepatocellular carcinoma (HCC), a cancer with high morbidity and mortality, has been extensively studied for its metabolic reprogramming-related mechanisms. Our study aims to identify the hotspots and frontiers of metabolic reprogramming research in HCC and to provide guidance for future scientific research and decision-making in HCC metabolism.

Methods

Relevant studies on the metabolic reprogramming of HCC were derived from the Web of Science Core Collection (WoSCC) database up until November 2023. The bibliometrix tools in R were used for scientometric analysis and visualization.

Results

From 2011 to 2023, a total of 575 publications were obtained from WoSCC that met the established criteria. These publications involved 3,904 researchers and 948 organizations in 37 countries, with an average annual growth rate of 39.11% in research. These studies were published in 233 journals, with Cancers (n = 29) ranking first, followed by Frontiers in Oncology (n = 20) and International Journal of Molecular Sciences (n = 19). The top ten journals accounted for 26% of the 575 studies. The most prolific authors were Wang J (n = 14), Li Y (n = 12), and Liu J (n = 12). The country with the most publications is China, followed by the United States, Italy, and France. Fudan University had the largest percentage of research results with 15.48% (n = 89). Ally A's paper in Cell has the most citations. A total of 1,204 keywords were analyzed, with the trend themes such as "glycolysis," "tumor microenvironment," "Warburg effect," "mitochondria," "hypoxia ," etc. Co-occurrence network and cluster analysis revealed the relationships between keywords, authors, publications, and journals. Moreover, the close collaboration between countries in this field was elucidated.

Conclusion

This bibliometric and visual analysis delves into studies related to metabolic reprogramming in HCC between 2012 and 2023, elucidating the characteristics of research in this field, which has gradually moved away from single glycolipid metabolism studies to the integration of overall metabolism in the body, pointing out the trend of research topics, and the dynamics of the interaction between the tumor microenvironment and metabolic reprogramming will be the future direction of research, which provides blueprints and inspirations for HCC prevention and treatment programs to the researchers in this field.

Systematic Review Registration: [https://www.bibliometrix.org].

Nanomaterial-Based Repurposing of Macrophage Metabolism and Its Applications

Macrophage immunotherapy represents an emerging therapeutic approach aimed at modulating the immune response to alleviate disease symptoms. Nanomaterials (NMs) have been engineered to monitor macrophage metabolism, enabling the evaluation of disease progression and the replication of intricate physiological signal patterns. They achieve this either directly or by delivering regulatory signals, thereby mapping phenotype to effector functions through metabolic repurposing to customize macrophage fate for therapy. However, a comprehensive summary regarding NM-mediated macrophage visualization and coordinated metabolic rewiring to maintain phenotypic equilibrium is currently lacking. This review aims to address this gap by outlining recent advancements in NM-based metabolic immunotherapy. We initially explore the relationship between metabolism, polarization, and disease, before delving into recent NM innovations that visualize macrophage activity to elucidate disease onset and fine-tune its fate through metabolic remodeling for macrophage-centered immunotherapy. Finally, we discuss the prospects and challenges of NM-mediated metabolic immunotherapy, aiming to accelerate clinical translation. We anticipate that this review will serve as a valuable reference for researchers seeking to leverage novel metabolic intervention-matched immunomodulators in macrophages or other fields of immune engineering.

The role of CD8 PET imaging in guiding cancer immunotherapy

Currently, immunotherapy is being widely used for treating cancers. However, the significant heterogeneity in patient responses is a major challenge for its successful application. CD8-positive T cells (CD8+ T cells) play a critical role in immunotherapy. Both their infiltration and functional status in tumors contribute to treatment outcomes. Therefore, accurate monitoring of CD8+ T cells, a potential biomarker, may improve therapeutic strategy. Positron emission tomography (PET) is an optimal option which can provide molecular imaging with enhanced specificity. This review summarizes the mechanism of action of CD8+ T cells in immunotherapy, and highlights the recent advancements in PET-based tracers that can visualize CD8+ T cells and discusses their clinical applications to elucidate their potential role in cancer immunotherapy.

Exploring the Surface: Sampling of Potential Skin Cancer Biomarkers Kynurenine and Tryptophan, Studied on 3D Melanocyte and Melanoma Models

Early detection of cancer via biomarkers is vital for improving patient survival rates. In the case of skin cancers, low-molecular-weight biomarkers can penetrate the skin barrier, enabling non-invasive sampling at an early stage. This study focuses on detecting tryptophan (Trp) and kynurenine (Kyn) on the surface of reconstructed 3D melanoma and melanocyte models. This is examined in connection with IDO-1 and IL-6 expression in response to IFN-γ or UVB stimulation, both crucial factors of the melanoma tumor microenvironment (TME). Using a polystyrene scaffold, full-thickness human skin equivalents containing fibroblasts, keratinocytes, and melanocytes or melanoma cells were developed. The samples were stimulated with IFN-γ or UVB, and Trp and Kyn secretion was measured using HPLC-PDA and HPLC-MS. The expression of IDO-1 and IL-6 was measured using RT-qPCR. Increased Trp catabolism to Kyn was observed in IFN-γ-stimulated melanoma and melanocyte models, along with higher IDO-1 expression. UVB exposure led to significant changes in Kyn levels but only in the melanoma model. This study demonstrates the potential of skin surface Trp and Kyn monitoring to capture TME metabolic changes. It also lays the groundwork for future in vivo studies, aiding in understanding and monitoring skin cancer progression.

Deciphering metabolic crosstalk in context: lessons from inflammatory diseases

Metabolism plays a crucial role in regulating the function of immune cells in both health and disease, with altered metabolism contributing to the pathogenesis of cancer and many inflammatory diseases. The local microenvironment has a profound impact on the metabolism of immune cells. Therefore, immunological and metabolic heterogeneity as well as the spatial organization of cells in tissues should be taken into account when studying immunometabolism. Here, we highlight challenges of investigating metabolic communication. Additionally, we review the capabilities and limitations of current technologies for studying metabolism in inflamed microenvironments, including single-cell omics techniques, flow cytometry-based methods (Met-Flow, single-cell energetic metabolism by profiling translation inhibition (SCENITH)), cytometry by time of flight (CyTOF), cellular indexing of transcriptomes and epitopes by sequencing (CITE-Seq), and mass spectrometry imaging. Considering the importance of metabolism in regulating immune cells in diseased states, we also discuss the applications of metabolomics in clinical research, as well as some hurdles to overcome to implement these techniques in standard clinical practice. Finally, we provide a flowchart to assist scientists in designing effective strategies to unravel immunometabolism in disease-relevant contexts.

From monocyte-derived macrophages to resident macrophages-how metabolism leads their way in cancer

Macrophages are innate immune cells that play key roles during both homeostasis and disease. Depending on the microenvironmental cues sensed in different tissues, macrophages are known to acquire specific phenotypes and exhibit unique features that, ultimately, orchestrate tissue homeostasis, defense, and repair. Within the tumor microenvironment, macrophages are referred to as tumor-associated macrophages (TAMs) and constitute a heterogeneous population. Like their tissue resident counterpart, TAMs are plastic and can switch function and phenotype according to the niche-derived stimuli sensed. While changes in TAM phenotype are known to be accompanied by adaptive alterations in their cell metabolism, it is reported that metabolic reprogramming of macrophages can dictate their activation state and function. In line with these observations, recent research efforts have been focused on defining the metabolic traits of TAM subsets in different tumor malignancies and understanding their role in cancer progression and metastasis formation. This knowledge will pave the way to novel therapeutic strategies tailored to cancer subtype-specific metabolic landscapes. This review outlines the metabolic characteristics of distinct TAM subsets and their implications in tumorigenesis across multiple cancer types.

Tumor-associated macrophages restrict CD8+ T cell function through collagen deposition and metabolic reprogramming of the breast cancer microenvironment

Tumor progression is accompanied by fibrosis, a condition of excessive extracellular matrix accumulation, which is associated with diminished antitumor immune infiltration. Here we demonstrate that tumor-associated macrophages (TAMs) respond to the stiffened fibrotic tumor microenvironment (TME) by initiating a collagen biosynthesis program directed by transforming growth factor-β. A collateral effect of this programming is an untenable metabolic milieu for productive CD8+ T cell antitumor responses, as collagen-synthesizing macrophages consume environmental arginine, synthesize proline and secrete ornithine that compromises CD8+ T cell function in female breast cancer. Thus, a stiff and fibrotic TME may impede antitumor immunity not only by direct physical exclusion of CD8+ T cells but also through secondary effects of a mechano-metabolic programming of TAMs, which creates an inhospitable metabolic milieu for CD8+ T cells to respond to anticancer immunotherapies.

Photodynamic therapy for cancer: mechanisms, photosensitizers, nanocarriers, and clinical studies

Photodynamic therapy (PDT) is a temporally and spatially precisely controllable, noninvasive, and potentially highly efficient method of phototherapy. The three components of PDT primarily include photosensitizers, oxygen, and light. PDT employs specific wavelengths of light to active photosensitizers at the tumor site, generating reactive oxygen species that are fatal to tumor cells. Nevertheless, traditional photosensitizers have disadvantages such as poor water solubility, severe oxygen-dependency, and low targetability, and the light is difficult to penetrate the deep tumor tissue, which remains the toughest task in the application of PDT in the clinic. Here, we systematically summarize the development and the molecular mechanisms of photosensitizers, and the challenges of PDT in tumor management, highlighting the advantages of nanocarriers-based PDT against cancer. The development of third generation photosensitizers has opened up new horizons in PDT, and the cooperation between nanocarriers and PDT has attained satisfactory achievements. Finally, the clinical studies of PDT are discussed. Overall, we present an overview and our perspective of PDT in the field of tumor management, and we believe this work will provide a new insight into tumor-based PDT.

Lactic acid: a narrative review of a promoter of the liver cancer microenvironment

Background and Objective

Lactic acid is a metabolite of glycolysis produced in the body, and its production is thought to be a mechanism by which cancer cells evade immune surveillance. Immune evasion and metabolic changes are well established as basic hallmarks of cancer. Although lactate has long been considered a waste product, it is now generally recognized to be a versatile small-molecule chemical that plays an important part in the tumor microenvironment (TME), with increased lactate production linked to the development of human malignancies. Metabolism in liver cancer is redirected toward glycolysis, which enhances the production of metabolic compounds used by tumor cells to produce proteins, lipids, and nucleotides, enabling them to maintain high proliferation rates and to establish the TME. Dysregulation of metabolic activity in liver cancer may impair antitumor responses owing to the immunosuppressive activity of the lactate produced by anaerobic glycolytic rates in tumor cells. This review primarily explores the link connection between lactic acid and the TME; evaluates the role of lactic acid in the occurrence, metastasis, prognosis, and treatment of liver cancer. Additionally, it investigates the associated pathways as potential targets for liver cancer treatment.

Methods

Literature searches were conducted in PubMed, Web of Science, and Google Scholar, with the publication date of the most recent article included being January 2024. After eliminating duplicate articles and less relevant articles through titles and abstracts, we selected 113 articles for this review. We categorized references into two categories. One is to classify the content into lactate-related, liver cancer-related and tumor metabolism-related. The other is to classify the article types, which are divided into reviews, research articles and clinical trials. Additionally, we consulted the reference lists of the relevant articles to ensure coverage was comprehensive and unbiased.

Key Content and Findings

The connection between lactic acid and the TME has recently become an area of intense research interest, and many related articles have been published in this field. The main finding of this review is to summarize the proven link between lactate and the TME and its possible impact on the TME of liver cancer. And analyzed the potential of lactate in liver cancer treatment and prognosis prediction.

Conclusions

Lactate may be key to developing novel approaches in the future treatment of liver cancer. Related research on the combination of classic therapies and molecular targeted drugs may provide innovative medicines that more selectively regulate immune cell activity.

Genomic Deletion of PFKFB3 Decreases In Vivo Tumorigenesis

Rapidly proliferative processes in mammalian tissues including tumorigenesis and embryogenesis rely on the glycolytic pathway for energy and biosynthetic precursors. The enzyme 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase-3 (PFKFB3) plays an important regulatory role in glycolysis by activating the key rate-limiting glycolytic enzyme, 6-phosphofructo-1-kinase (PFK-1). We have previously determined that decreased PFKFB3 expression reduced glycolysis and growth in transformed cells in vitro and suppressed xenograft growth in vivo. In earlier studies, we created a constitutive knockout mouse to interrogate the function of PFKFB3 in vivo but failed to generate homozygous offspring due to the requirement for PFKFB3 for embryogenesis. We have now developed a novel transgenic mouse model that exhibits inducible homozygous pan-tissue Pfkfb3 gene deletion (Pfkfb3fl/fl). We have induced Pfkfb3 genomic deletion in these mice and found that it effectively decreased PFKFB3 expression and activity. To evaluate the functional consequences of Pfkfb3 deletion in vivo, we crossed Cre-bearing Pfkfb3fl/fl mice with oncogene-driven tumor models and found that Pfkfb3 deletion markedly decreased their glucose uptake and growth. In summary, our studies reveal a critical regulatory function for PFKFB3 in glycolysis and tumorigenesis in vivo and characterize an effective and powerful model for further investigation of its role in multiple biological processes.

Dependence on mitochondrial respiration of malignant T cells reveals a new therapeutic target for angioimmunoblastic T-cell lymphoma

Cancer metabolic reprogramming has been recognized as one of the cancer hallmarks that promote cell proliferation, survival, as well as therapeutic resistance. Up-to-date regulation of metabolism in T-cell lymphoma is poorly understood. In particular, for human angioimmunoblastic T-cell lymphoma (AITL) the metabolic profile is not known. Metabolic intervention could help identify new treatment options for this cancer with very poor outcomes and no effective medication. Transcriptomic analysis of AITL tumor cells, identified that these cells use preferentially mitochondrial metabolism. By using our preclinical AITL mouse model, mimicking closely human AITL features, we confirmed that T follicular helper (Tfh) tumor cells exhibit a strong enrichment of mitochondrial metabolic signatures. Consistent with these results, disruption of mitochondrial metabolism using metformin or a mitochondrial complex I inhibitor such as IACS improved the survival of AITL lymphoma-bearing mice. Additionally, we confirmed a selective elimination of the malignant human AITL T cells in patient biopsies upon mitochondrial respiration inhibition. Moreover, we confirmed that diabetic patients suffering from T-cell lymphoma, treated with metformin survived longer as compared to patients receiving alternative treatments. Taking together, our findings suggest that targeting the mitochondrial metabolic pathway could be a clinically efficient approach to inhibit aggressive cancers such as peripheral T-cell lymphoma.

Role and recent progress of P2Y12 receptor in cancer development

P2Y12 receptor (P2Y12R) is an adenosine-activated G protein-coupled receptor (GPCR) that plays a central role in platelet function, hemostasis, and thrombosis. P2Y12R activation can promote platelet aggregation and adhesion to cancer cells, promote tumor angiogenesis, and affect the tumor immune microenvironment (TIME) and tumor drug resistance, which is conducive to the progression of cancers. Meanwhile, P2Y12R inhibitors can inhibit this effect, suggesting that P2Y12R may be a potential therapeutic target for cancer. P2Y12R is involved in cancer development and metastasis, while P2Y12R inhibitors are effective in inhibiting cancer. However, a new study suggests that long-term use of P2Y12R inhibitors may increase the risk of cancer and the mechanism remains to be explored. In this paper, we reviewed the structural and functional characteristics of P2Y12R and its role in cancer. We explored the role of P2Y12R inhibitors in different tumors and the latest advances by summarizing the basic and clinical studies on the effects of P2Y12R inhibitors on tumors.

A pan-cancer single-cell transcriptional analysis of antigen-presenting cancer-associated fibroblasts in the tumor microenvironment

Background

Cancer-associated fibroblasts (CAFs) are the primary stromal cells found in tumor microenvironment, and display high plasticity and heterogeneity. By using single-cell RNA-seq technology, researchers have identified various subpopulations of CAFs, particularly highlighting a recently identified subpopulation termed antigen-presenting CAFs (apCAFs), which are largely unknown.

Methods

We collected datasets from public databases for 9 different solid tumor types to analyze the role of apCAFs in the tumor microenvironment.

Results

Our data revealed that apCAFs, likely originating mainly from normal fibroblast, are commonly found in different solid tumor types and generally are associated with anti-tumor effects. apCAFs may be associated with the activation of CD4+ effector T cells and potentially promote the survival of CD4+ effector T cells through the expression of C1Q molecules. Moreover, apCAFs exhibited highly enrichment of transcription factors RUNX3 and IKZF1, along with increased glycolytic metabolism.

Conclusions

Taken together, these findings offer novel insights into a deeper understanding of apCAFs and the potential therapeutic implications for apCAFs targeted immunotherapy in cancer.

Dichloroacetate for Cancer Treatment: Some Facts and Many Doubts

Rarely has a chemical elicited as much controversy as dichloroacetate (DCA). DCA was initially considered a dangerous toxic industrial waste product, then a potential treatment for lactic acidosis. However, the main controversies started in 2008 when DCA was found to have anti-cancer effects on experimental animals. These publications showed contradictory results in vivo and in vitro such that a thorough consideration of this compound's in cancer is merited. Despite 50 years of experimentation, DCA's future in therapeutics is uncertain. Without adequate clinical trials and health authorities' approval, DCA has been introduced in off-label cancer treatments in alternative medicine clinics in Canada, Germany, and other European countries. The lack of well-planned clinical trials and its use by people without medical training has discouraged consideration by the scientific community. There are few thorough clinical studies of DCA, and many publications are individual case reports. Case reports of DCA's benefits against cancer have been increasing recently. Furthermore, it has been shown that DCA synergizes with conventional treatments and other repurposable drugs. Beyond the classic DCA target, pyruvate dehydrogenase kinase, new target molecules have also been recently discovered. These findings have renewed interest in DCA. This paper explores whether existing evidence justifies further research on DCA for cancer treatment and it explores the role DCA may play in it.

Recreating metabolic interactions of the tumour microenvironment

Tumours are heterogeneous tissues containing diverse populations of cells and an abundant extracellular matrix (ECM). This tumour microenvironment prompts cancer cells to adapt their metabolism to survive and grow. Besides epigenetic factors, the metabolism of cancer cells is shaped by crosstalk with stromal cells and extracellular components. To date, most experimental models neglect the complexity of the tumour microenvironment and its relevance in regulating the dynamics of the metabolism in cancer. We discuss emerging strategies to model cellular and extracellular aspects of cancer metabolism. We highlight cancer models based on bioengineering, animal, and mathematical approaches to recreate cell-cell and cell-matrix interactions and patient-specific metabolism. Combining these approaches will improve our understanding of cancer metabolism and support the development of metabolism-targeting therapies.