Lactate modulation of immune responses in inflammatory versus tumour microenvironments

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.

Tumor microenvironment ameliorative and adaptive nanoparticles with photothermal-to-photodynamic switch for cancer phototherapy

The notorious tumor microenvironment (TME) usually becomes more deteriorative during phototherapeutic progress that hampers the antitumor efficacy. To overcome this issue, we herein report the ameliorative and adaptive nanoparticles (TPASIC-PFH@PLGA NPs) that simultaneously reverse hypoxia TME and switch photoactivities from photothermal-dominated state to photodynamic-dominated state to maximize phototherapeutic effect. TPASIC-PFH@PLGA NPs are designed by incorporating oxygen-rich liquid perfluorohexane (PFH) into the intraparticle microenvironment to regulate the intramolecular motions of AIE photosensitizer TPASIC. TPASIC exhibits a unique aggregation-enhanced reactive oxygen species (ROS) generation feature. PFH incorporation affords TPASIC the initially dispersed state, thus promoting active intramolecular motions and photothermal conversion efficiency. While PFH volatilization leads to nanoparticle collapse and the formation of tight TPASIC aggregates with largely enhanced ROS generation efficiency. As a consequence, PFH incorporation not only currently promotes both photothermal and photodynamic efficacies of TPASIC and increases the intratumoral oxygen level, but also enables the smart photothermal-to-photodynamic switch to maximize the phototherapeutic performance. The integration of PFH and AIE photosensitizer eventually delivers more excellent antitumor effect over conventional phototherapeutic agents with fixed photothermal and photodynamic efficacies. This study proposes a new nanoengineering strategy to ameliorate TME and adapt the treatment modality to fit the changed TME for advanced antitumor applications.

Emerging role of metabolic reprogramming in the immune microenvironment and immunotherapy of thyroid cancer

The metabolic reprogramming of cancer cells is a hallmark of many malignancies. To meet the energy acquisition needs of tumor cells for rapid proliferation, tumor cells reprogram their nutrient metabolism, which is caused by the abnormal expression of transcription factors and signaling molecules related to energy metabolic pathways as well as the upregulation and downregulation of abnormal metabolic enzymes, receptors, and mediators. Thyroid cancer (TC) is the most common endocrine tumor, and immunotherapy has become the mainstream choice for clinical benefit after the failure of surgical, endocrine, and radioiodine therapies. TC change the tumor microenvironment (TME) through nutrient competition and metabolites, causing metabolic reprogramming of immune cells, profoundly changing immune cell function, and promoting immune evasion of tumor cells. A deeper understanding of how metabolic reprogramming alters the TME and controls immune cell fate and function will help improve the effectiveness of TC immunotherapy and patient outcomes. This paper aims to elucidate the metabolic communication that occurs between immune cells around TC and discusses how metabolic reprogramming in TC affects the immune microenvironment and the effectiveness of anti-cancer immunotherapy. Finally, targeting key metabolic checkpoints during metabolic reprogramming, combined with immunotherapy, is a promising strategy.

Systematic and comprehensive insights into HIF-1 stabilization under normoxic conditions: implications for cellular adaptation and therapeutic strategies in cancer

Hypoxia-inducible factors (HIFs) are essential transcription factors that orchestrate cellular responses to oxygen deprivation. HIF-1α, as an unstable subunit of HIF-1, is usually hydroxylated by prolyl hydroxylase domain enzymes under normoxic conditions, leading to ubiquitination and proteasomal degradation, thereby keeping low levels. Instead of hypoxia, sometimes even in normoxia, HIF-1α translocates into the nucleus, dimerizes with HIF-1β to generate HIF-1, and then activates genes involved in adaptive responses such as angiogenesis, metabolic reprogramming, and cellular survival, which presents new challenges and insights into its role in cellular processes. Thus, the review delves into the mechanisms by which HIF-1 maintains its stability under normoxia including but not limited to giving insights into transcriptional, translational, as well as posttranslational regulation to underscore the pivotal role of HIF-1 in cellular adaptation and malignancy. Moreover, HIF-1 is extensively involved in cancer and cardiovascular diseases and potentially serves as a bridge between them. An overview of HIF-1-related drugs that are approved or in clinical trials is summarized, highlighting their potential capacity for targeting HIF-1 in cancer and cardiovascular toxicity related to cancer treatment. The review provides a comprehensive insight into HIF-1's regulatory mechanism and paves the way for future research and therapeutic development.

PDHX acetylation facilitates tumor progression by disrupting PDC assembly and activating lactylation-mediated gene expression

Deactivation of the mitochondrial pyruvate dehydrogenase complex (PDC) is important for the metabolic switching of cancer cell from oxidative phosphorylation to aerobic glycolysis. Studies examining PDC activity regulation have mainly focused on the phosphorylation of pyruvate dehydrogenase (E1), leaving other post-translational modifications largely unexplored. Here, we demonstrate that the acetylation of Lys 488 of pyruvate dehydrogenase complex component X (PDHX) commonly occurs in hepatocellular carcinoma, disrupting PDC assembly and contributing to lactate-driven epigenetic control of gene expression. PDHX, an E3-binding protein in the PDC, is acetylated by the p300 at Lys 488, impeding the interaction between PDHX and dihydrolipoyl transacetylase (E2), thereby disrupting PDC assembly to inhibit its activation. PDC disruption results in the conversion of most glucose to lactate, contributing to the aerobic glycolysis and H3K56 lactylation-mediated gene expression, facilitating tumor progression. These findings highlight a previously unrecognized role of PDHX acetylation in regulating PDC assembly and activity, linking PDHX Lys 488 acetylation and histone lactylation during hepatocellular carcinoma progression and providing a potential biomarker and therapeutic target for further development.

Intrinsic immunomodulatory hydrogels for chronic inflammation

The immune system plays a pivotal role in maintaining physiological homeostasis and influencing disease processes. Dysregulated immune responses drive chronic inflammation, which in turn results in a range of diseases that are among the leading causes of death globally. Traditional immune interventions, which aim to regulate either insufficient or excessive inflammation, frequently entail lifelong comorbidities and the risk of severe side effects. In this context, intrinsic immunomodulatory hydrogels, designed to precisely control the local immune microenvironment, have recently attracted increasing attention. In particular, these advanced hydrogels not only function as delivery mechanisms but also actively engage in immune modulation, optimizing interactions with the immune system for enhanced tissue repair, thereby providing a sophisticated strategy for managing chronic inflammation. In this tutorial review, we outline key elements of chronic inflammation and subsequently explore the strategic design principles of intrinsic immunomodulatory hydrogels based on these elements. Finally, we examine the challenges and prospects of such immunomodulatory hydrogels, which are expected to inspire further preclinical research and clinical translation in addressing chronic inflammation.

Microglia lactylation in relation to central nervous system diseases

The development of neurodegenerative diseases is closely related to the disruption of central nervous system homeostasis. Microglia, as innate immune cells, play important roles in the maintenance of central nervous system homeostasis, injury response, and neurodegenerative diseases. Lactate has been considered a metabolic waste product, but recent studies are revealing ever more of the physiological functions of lactate. Lactylation is an important pathway in lactate function and is involved in glycolysis-related functions, macrophage polarization, neuromodulation, and angiogenesis and has also been implicated in the development of various diseases. This review provides an overview of the lactate metabolic and homeostatic regulatory processes involved in microglia lactylation, histone versus non-histone lactylation, and therapeutic approaches targeting lactate. Finally, we summarize the current research on microglia lactylation in central nervous system diseases. A deeper understanding of the metabolic regulatory mechanisms of microglia lactylation will provide more options for the treatment of central nervous system diseases.

Metabolic plasticity in pancreatic cancer: The mitochondrial connection

BACKGROUND

Cellular metabolism plays a pivotal role in the development and progression of pancreatic ductal adenocarcinoma (PDAC), with dysregulated metabolic pathways contributing to tumorigenesis and therapeutic resistance. Distinct metabolic heterogeneity in pancreatic cancer significantly impacts patient prognosis, as variations in metabolic profiles influence tumor behavior and treatment responses.

SCOPE OF THE REVIEW

This review explores the intricate interplay between mitochondrial dynamics, mitophagy, and cellular metabolism in PDAC. We discuss the significance of mitophagy dysregulation in PDAC pathogenesis, emphasizing its influence on treatment responses and prognosis. Furthermore, we analyze the impact of mitochondrial dynamics alterations, including fission and fusion processes, on PDAC progression and tumorigenesis.

MAJOR CONCLUSION

Targeting mitochondrial metabolism holds promise for advancing PDAC therapeutics. Ongoing clinical trials underscore the therapeutic potential of modulating key regulators of mitochondrial dynamics and mitophagy. Despite inherent challenges, these approaches offer diverse strategies to enhance treatment efficacy and improve patient outcomes.

I-Motif DNA Based Fluorescent Ratiometric Microneedle Sensing Patch for Sensitive Response of Small pH Variations in Interstitial Fluid

Detection of slight pH changes in skin interstitial fluid (ISF) is crucial yet challenging for studying pathological processes and understanding personal health conditions. In this work, we construct an i-motif DNA based fluorescent ratiometric microneedle sensing patch (IFR-pH MN patch) strategy that enables minimally invasive, high-resolution, and sensitive transdermal monitoring of small pH variations in ISF. The IFR-pH MN patch with advanced integration of both ISF sampling and pH sensing was fabricated from the cross-linking of gelatin methacryloyl and methacrylated hyaluronic acid, wrapping with pH-sensitive hairpin-containing i-motif DNA based fluorescent ratiometric probes in the matrix. Because it is mechanically robust for skin penetration and has high swelling ability, the IFR-pH MN patch could be quickly extracted as sufficient liquid from agarose gel (∼56.4 μL in 10 min). Benefiting from conformation changes of the hairpin-containing i-motif DNA under pH variation and ratiometric fluorescence signal readout, the IFR-pH MN patch could quantitate pH over a small range between pH 6.2 and 6.9 with an accuracy of 0.2 pH units in the mimic skin model. Furthermore, in vivo testing on wound and tumor mouse models indicated the ability of the biocompatible IFR-pH MN patch to penetrate the skin for obtaining transdermal pH values, demonstrating the potential applications in monitoring and intervention of pathological states.

Carbonic anhydrase 2 facilitates sorafenib resistance by counteracting MCT4-mediated intracellular pH dysregulation in HCC

Sorafenib, the targeted therapy for hepatocellular carcinoma (HCC), has been utilized in clinics for over a decade. However, its effectiveness is severely hindered by acquired drug resistance, the mechanisms of which remain largely elusive. In this study, we identify that carbonic anhydrase 2 (CA2) is a key regulator of sorafenib resistance. Mechanistically, sorafenib treatment decreases intracellular pH (pHi) by suppressing monocarboxylate transporter 4 (MCT4) expression, while high levels of CA2 counteract MCT4-mediated pHi dysregulation upon sorafenib treatment, maintaining pHi homeostasis to facilitate cell survival and sorafenib resistance. Targeting CA2 re-sensitizes resistant HCC cells to sorafenib both in vitro and in vivo. Importantly, analysis of clinical samples shows a strong correlation between CA2 expression levels and the therapeutic efficacy of sorafenib in HCC patients. Our findings highlight the significance of CA2 in facilitating sorafenib resistance and propose targeting CA2 as a potential strategy for overcoming sorafenib resistance in HCC patients.

NSUN2 lactylation drives cancer cell resistance to ferroptosis through enhancing GCLC-dependent glutathione synthesis

Lactate-mediated lactylation on target proteins is recently identified as the novel posttranslational modification with profound biological functions. RNA 5-methylcytosine (m5C) modification possesses dynamic and reversible nature, suggesting that activity of its methyltransferase NSUN2 is actively regulated. However, how NSUN2 activity is response to acidic condition in tumor microenvironment and then regulates cancer cell survival remain to be clarified. Here, we demonstrate that NSUN2 activity is enhanced by lactate-mediated lactylation at lysine 508, which then targets glutamate-cysteine ligase catalytic subunit (GCLC) mRNA to facilitates GCLC m5C formation and mRNA stabilization. The activated GCLC induces higher level of intracellular GSH accompanied by decreased lipid peroxidation and resistant phenotype to ferroptosis induction by doxorubicin (Dox) in gastric cancer cells. Specifically, the effect of NSUN2 lactylation-GCLC-GSH pathway is nearly lost when NSUN2 K508R or GCLC C-A mutant (five cytosine sites) was introduced into the cancer cells. We further identify the catalytic subunit N-α-acetyltransferase 10 (NAA10) as the lactytransferase of NSUN2, and lactate treatment substantially enhances their association and consequent NSUN2 activation. Taken together, our findings convincingly elucidate the signaling axis of NAA10-NSUN2-GCLC that potently antagonizes the ferroptosis under acidic condition, and therefore, targeting NSUN2 lactylation might be an effective strategy in improving the prognosis of cancer patients.

Comprehensive analysis of lysine lactylation and its potential biological significance in clear cell renal cell carcinoma

BACKGROUND

Clear cell renal cell carcinoma (ccRCC) is a common histological subtype of malignant renal neoplasm. Protein lysine lactylation (Kla) plays a crucial role in tumor metabolic reprogramming. However, little is known regarding the distribution and potential biological functions of Kla in ccRCC. This study aimed to systematically investigate the role of Kla in ccRCC.

METHODS

A total of 12 ccRCC samples were collected from 6 patients. Western blotting was performed to determine the trend of Kla-modified proteins in ccRCC. Liquid chromatography-tandem mass spectrometry was used to quantitatively analyze Kla in ccRCC. Gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and protein-protein interaction (PPI) network analyses were conducted to clarify the biological functions and interactional relationships of differentially lactylated proteins (DLPs).

RESULTS

In total, 239 DLPs, including 441 lactylated sites, were identified by comparing ccRCC tissues with adjacent normal tissues. Kla-related enzymes have a higher affinity for alanine than for other amino acid residues in ccRCC. Subcellular localization analysis revealed that most DLPs were localized in the cytoplasm and mitochondria. GO enrichment analysis showed that most of the DLPs were enriched in metabolism-associated biological processes, including the purine ribonucleotide, monocarboxylic acid, ribonucleoside triphosphate, purine nucleoside triphosphate, and ATP metabolic processes. KEGG analysis indicated that most DLPs were also enriched in metabolism-related pathways, including glycolysis, amino acid (valine, leucine, and isoleucine) degradation, pyruvate metabolism, fatty acid degradation, and the citrate cycle. The top 20 hub proteins were screened from the PPI network based on their degree ranks.

CONCLUSIONS

This study revealed the role of Kla in ccRCC, which will extend our understanding of the potential molecular mechanisms underlying ccRCC formation and progression. These key Kla-modified proteins may be promising therapeutic targets for the treatment of ccRCC. However, further molecular experiments are required to validate these findings.

Cancer Biology and the Perioperative Period: Opportunities for Disease Evolution and Challenges for Perioperative Care

Efforts to deconvolve the complex interactions of cancer cells with other components of the tumor micro- and macro-environment have exposed a common tendency for cancers to subvert systems physiology and exploit endogenous programs involved in homeostatic control of metabolism, immunity, regeneration, and repair. Many such programs are engaged in the healing response to surgery which, together with other abrupt biochemical changes in the perioperative period, provide an opportunity for the macroevolution of residual disease. This review relates contemporary perspectives of cancer as a systemic disease with the overlapping biology of host responses to surgery and events within the perioperative period. With a particular focus on examples of cancer cell plasticity and changes within the host, we explore how perioperative inflammation and acute metabolic, neuroendocrine, and immune dyshomeostasis might contribute to cancer evolution within this contextually short, yet crucially influential timeframe, and highlight potential therapeutic opportunities within to further optimize surgical cancer care and its long-term oncological outcomes.

Yanghe decoction inhibits inflammation-induced lung metastasis of colorectal cancer

ETHNOPHARMACOLOGICAL RELEVANCE

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

AIM OF THE STUDY

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

Cancer specific up-regulated lactate genes associated with immunotherapy resistance in a pan-cancer analysis

Background

Although the lactate pathway has been reported to lead to immune escape through the inhibition of effector T cells, the cancer-intrinsic lactate signature has not been identified, and the immunotherapeutic efficacy and potential mechanism of the lactate signature are still unclear.

Methods

We defined a pan-cancer up-lactate score by comparing malignant tissues and normal tissues in the TCGA cohort. The immunotherapeutic efficacy was evaluated in non-small cell lung cancer (NSCLC), metastatic renal cancer (mRCC), bladder cancer (BLCA) and melanoma cohorts. The cancer cell-intrinsic mechanism to immune checkpoint inhibitors (ICIs) resistance was measured using single cell sequencing (scRNA-seq) data. Pathway activation was evaluated in the TCGA cohort and CPTAC cohort with transcriptomics and proteomics. The co-occurrence of up-lactate signature and mTOR signaling was determined by spatial transcriptomics of the tissue samples. Immunotherapy resistance and pathway regulation were validated in the in-house NSCLC cohort.

Results

Patients with the high up-lactate scores had significantly short overall survival (OS) than those with the low up-lactate scores (p < 0.001) across multiple types of cancers. The up-regulated lactate signature exhibited higher expression in the malignant cells compared with stromal cells and immune cells in multiple scRNA-seq datasets. A high up-lactate score was associated with poor OS in NSCLC, mRCC, BLCA and melanoma patients who received anti-PD(L)1 antibody. The up-lactate score was higher in the responders of cancer cells, but not in immune cells and stromal cells compared with the non-responders (p < 0.05). Moreover, up-lactate score was positively correlated with mTOR signaling across multiple cancers. In patients with NSCLC who received anti-PD-1 antibody, higher up-lactate scores were associated with significantly shorter PFS compared to lower up-lactate scores (p < 0.001). Additionally, the up-lactate score was associated with cold tumor, and was positively correlated with mTOR signaling.

Conclusion

Collectively, we defined a pan-cancer up-lactate signature, which is a feature of malignant cells and is associated with ICIs resistance. This reveals a coherent program with prognostic and predictive value that may be therapeutically targeted.

Tumor-Targeted Catalytic Immunotherapy

Cancer immunotherapy holds significant promise for improving cancer treatment efficacy; however, the low response rate remains a considerable challenge. To overcome this limitation, advanced catalytic materials offer potential in augmenting catalytic immunotherapy by modulating the immunosuppressive tumor microenvironment (TME) through precise biochemical reactions. Achieving optimal targeting precision and therapeutic efficacy necessitates a thorough understanding of the properties and underlying mechanisms of tumor-targeted catalytic materials. This review provides a comprehensive and systematic overview of recent advancements in tumor-targeted catalytic materials and their critical role in enhancing catalytic immunotherapy. It highlights the types of catalytic reactions, the construction strategies of catalytic materials, and their fundamental mechanisms for tumor targeting, including passive, bioactive, stimuli-responsive, and biomimetic targeting approaches. Furthermore, this review outlines various tumor-specific targeting strategies, encompassing tumor tissue, tumor cell, exogenous stimuli-responsive, TME-responsive, and cellular TME targeting strategies. Finally, the discussion addresses the challenges and future perspectives for transitioning catalytic materials into clinical applications, offering insights that pave the way for next-generation cancer therapies and provide substantial benefits to patients in clinical settings.

Targeting metabolic dysfunction of CD8 T cells and natural killer cells in cancer

The importance of metabolic pathways in regulating immune responses is now well established, and a mapping of the bioenergetic metabolism of different immune cell types is under way. CD8 T cells and natural killer (NK) cells contribute to cancer immunosurveillance through their cytotoxic functions and secretion of cytokines and chemokines, complementing each other in target recognition mechanisms. Several immunotherapies leverage these cell types by either stimulating their activity or redirecting their specificity against tumour cells. However, the anticancer activity of CD8 T cells and NK cells is rapidly diminished in the tumour microenvironment, closely linked to a decline in their metabolic capacities. Various strategies have been developed to restore cancer immunosurveillance, including targeting bioenergetic metabolism or genetic engineering. This Review provides an overview of metabolic dysfunction in CD8 T cells and NK cells within the tumour microenvironment, highlighting current therapies aiming to overcome these issues.

Evaluating lactate metabolism for prognostic assessment and therapy response prediction in gastric cancer with emphasis on the oncogenic role of SLC5A12

BACKGROUND

Gastric cancer remains a common malignancy with poor prognosis. While lactate metabolism is recognized as a significant factor in tumor progression, its potential as a predictive tool for treatment response remains unexplored. This study introduces a novel Lactate-Related Gene Signature (LRGS) designed to predict both survival outcomes and therapy responses in gastric cancer patients.

METHODS

We comprehensively analyzed 335 lactate-related genes from 11 metabolic pathways using MSigDB, identifying 278 differentially expressed genes between gastric cancer and normal tissues. Employing the LASSO Cox regression model, we developed an innovative LRGS formula based on the expression of 16 key lactate-related genes. The impact of Solute Carrier Family 5 Member 12 (SLC5A12), a gene of particular interest, on gastric cancer cell functions was evaluated using in vitro assays and an in vivo zebrafish model.

RESULTS

Our newly established LRGS demonstrated robust capability in stratifying gastric cancer patients by survival risk. Notably, the LRGS-low subtype showed significantly improved overall and disease-free survival rates compared to the LRGS-high subtype. A key finding was LRGS's ability to predict patient responses to both adjuvant chemotherapy and immunotherapy. Random forest analysis identified SLC5A12 as the most significant gene differentiating gastric cancer from normal tissues. Functional experiments confirmed SLC5A12's role in promoting gastric cancer cell proliferation, invasion, and migration both in vitro and in vivo.

CONCLUSION

The LRGS is a dependable and efficient prognostic tool for assessing the survival outcomes in individuals with gastric cancer, as well as a predictor of patient response to adjuvant chemotherapy and immunotherapy.

D-sodium lactate promotes the activation of NF-κB signaling pathway induced by lipopolysaccharide via histone lactylation in bovine mammary epithelial cells

Lactate is a glycolytic end product that is further metabolized as an energy source. This end product has been associated with certain diseases, including sepsis and tumors, and it can regulate the transition of macrophages to an anti-inflammatory state. This study aimed to explore the effects of lactate on the inflammatory responses of mammary gland epithelial cells, which constitute the first line of defense against pathogens in mammary glands. Bovine mammary epithelial cells (BMECs) were challenged with lipopolysaccharide (LPS) in the presence or absence of D-sodium lactate (D-nala). LPS exposure increased the concentration of lactate both inside and outside the cells. Further, inhibiting glycolysis diminished the LPS-induced production of proinflammatory cytokines. Treatment with LPS, exogenous D-nala, and their combination upregulated the expression levels of MCT1, increased the intracellular levels of lactate and histone H3 lysine 18 lactylation (H3K18la), and activated the nuclear factor kappa-light-chain-enhancer of activated B cell (NF-κB) signaling pathway. The lactylation of H3K18 was mediated by p300/CBP. The p300/CBP inhibitor C646 decreased the level of H3K18la, reversing the activation of the NF-κB signaling pathway and release of proinflammatory cytokines. Therefore, LPS increased the intracellular level of lactate by upregulating MCT1 and glycolysis. D-nala exacerbated the LPS-induced inflammatory responses in BMECs. Moreover, intracellular lactate enhanced the activation of the NF-κB signaling pathway through the p300/CBP-mediated lactylation of H3K18. Thus, the findings of this study expand our understanding of lactate function in immune regulation.

Dendrimer/Copper(II) Complex-Mediated siRNA Delivery Disrupts Lactate Metabolism to Reprogram the Local Immune Microenvironment against Tumor Growth and Metastasis

Solid tumors reprogram metabolic pathways to meet their biosynthesis demands, resulting in elevated levels of metabolites in the tumor microenvironment (TME), including lactate. Excessive accumulation and active transportation of lactate within the TME drives tumor progression, metastasis, and immunosuppression. Interruption of TME lactate metabolism is expected to restore antitumor responses and sensitize tumor immunotherapy. Herein, we developed phenylboronic acid- and pyridine-modified poly(amidoamine) dendrimer/copper(II) (Cu(II)) complexes, namely, D-Cu complexes, to deliver monocarboxylate transporter 4 siRNA (siMCT4) and disrupt the tumor lactate shuttle. The D-Cu complexes are shown to have a Cu(II)-mediated chemodynamic effect and T1-weighted magnetic resonance imaging potential (r1 relaxivity = 1.19 mM-1 s-1), enabling effective siMCT4 delivery to inhibit lactate efflux within cancer cells. In combination with a CD11b immune agonist, the treatment of D-Cu/siMCT4 polyplexes in a mouse breast tumor model alleviates local TME immunosuppression, leading to excellent inhibition of both primary tumor growth and lung metastasis.

A low level of tumor necrosis factor α in tumor microenvironment maintains the self-renewal of glioma stem cells by Vasorin-mediated glycolysis

BACKGROUND

Self-renewal of glioma stem cells (GSCs) is responsible for glioblastoma (GBM) therapy resistance and recurrence. Tumor necrosis factor α (TNFα) and TNF signaling pathway display an antitumor activity in preclinical models and in tumor patients. However, TNFα exhibits no significance for glioma clinical prognosis based on the Glioma Genome Atlas database. This study aimed to explore whether TNFα of tumor microenvironment maintains self-renewal of GSCs and promotes worse prognosis in glioma patients.

METHODS

Spatial transcriptomics, immunoblotting, sphere formation assay, extreme limiting dilution, and gene expression analysis were used to determine the role of TNFα on GSC's self-renewal. Mass spectrometry, RNA-sequencing detection, bioinformatic analyses, qRT-RNA, immunofluorescence, immunohistochemistry, single-cell RNA sequencing, in vitro and in vivo models were used to uncover the mechanism of TNFα-induced GSC self-renewal.

RESULTS

A low level of TNFα displays a promoting effect on GSC self-renewal and worse glioma prognosis. Mechanistically, Vasorin (VASN) mediated TNFα-induced self-renewal by potentiating glycolysis. Lactate produced by glycolysis inhibits the TNFα secretion of tumor-associated macrophages (TAMs) and maintains TNFα at a low level.

CONCLUSIONS

TNFα-induced GSC self-renewal mediated by VASN provides a possible explanation for the failures of endogenous TNFα effect on GBM. A combination of targeting VASN and TNFα antitumor effect may be an effective approach for treating GBM.

Mitochondrial metabolic reprogramming of macrophages and T cells enhances CD47 antibody-engineered oncolytic virus antitumor immunity

BACKGROUND

Although immunotherapy can reinvigorate immune cells to clear tumors, the response rates are poor in some patients. Here, CD47 antibody-engineered oncolytic viruses (oAd-αCD47) were employed to lyse tumors and activate immunity. The oAd-αCD47 induced comprehensive remodeling of the tumor microenvironment (TME). However, whether the acidic TME affects the antitumor immunotherapeutic effects of oncolytic viruses-αCD47 has not been clarified.

METHODS

To assess the impact of oAd-αCD47 treatment on the TME, we employed multicolor flow cytometry. Glucose uptake was quantified using 2NBDG, while mitochondrial content was evaluated with MitoTracker FM dye. pH imaging of tumors was performed using the pH-sensitive fluorophore SNARF-4F. Moreover, changes in the calmodulin-dependent protein kinase II (CaMKII)/cyclic AMP activates-responsive element-binding proteins (CREB) and peroxisome proliferator-activated receptor gamma coactivator-1α (PGC1α) signaling pathway were confirmed through western blotting and flow cytometry.

RESULTS

Here, we identified sodium bicarbonate (NaBi) as the potent metabolic reprogramming agent that enhanced antitumor responses in the acidic TME. The combination of NaBi and oAd-αCD47 therapy significantly inhibited tumor growth and produced complete immune control in various tumor-bearing mouse models. Mechanistically, combination therapy mainly reduced the number of regulatory T cells and enriched the ratio of M1-type macrophages TAMs (M1.TAMs) to M2-type macrophages TAMs (M2.TAMs), while decreasing the abundance of PD-1+TIM3+ expression and increasing the expression of CD107a in the CD8+ T cells. Furthermore, the combination therapy enhanced the metabolic function of T cells and macrophages by upregulating PGC1α, a key regulator of mitochondrial biogenesis. This metabolic improvement contributed to a robust antitumor response. Notably, the combination therapy also promoted the generation of memory T cells, suggesting its potential as an effective neoadjuvant treatment for preventing postoperative tumor recurrence and metastasis.

CONCLUSIONS

Tumor acidic microenvironment impairs mitochondrial energy metabolism in macrophages and T cells inducing oAd-αCD47 immunotherapeutic resistance. NaBi improves the acidity of the TME and activates the CaMKII/CREB/PGC1α mitochondrial biosynthesis signaling pathway, which reprograms the energy metabolism of macrophages and T cells in the TME, and oral NaBi enhances the antitumor effect of oAd-αCD47.

LDHA-induced histone lactylation mediates the development of osteoarthritis through regulating the transcription activity of TPI1 gene

Osteoarthritis (OA) is a worldwide joint disease, leading to the physical pain, stiffness, and even disability. Lactate dehydrogenase A (LDHA) is known as a lactylation mediator that can regulate histone lactylation of its target genes. However, the role of LDHA-mediated histone H3 lysine 18 lactylation (H3K18la) in OA progression is yet to be clarified. Our study aims at revealing the role and mechanism of LDHA-mediated histone lactylation in the glycolysis of chondrocytes. In this study, we determined at first that the H3K18la level was enhanced in OA. Energy metabolism such as glycolysis is often altered in OA progress. Therefore, we further explored the mechanism mediating glycolysis and thus promoting OA progress. Moreover, glycolysis was enhanced in LPS-induced OA cell model, as evidenced by the increased glucose consumption and lactate production. Furthermore, we silenced LDHA for loss-of-function assays. The results showed that knockdown of LDHA suppressed glycolysis of LPS-induced chondrocytes. In vivo animal study demonstrated that knockout of LDHA recovered cartilage injury of OA mice. Mechanistically, we uncovered that LDHA-mediated H3K18la in TPI1 promoter enhanced the transcription activity of TPI1. Mutation of K69 site was found to ameliorate LPS-induced glycolysis in OA cell model. In conclusion, our study reveals the role of LDHA-mediated H3K18la of TPI1 promoter in OA progress.

Oncometabolites at the crossroads of genetic, epigenetic and ecological alterations in cancer

By the time a tumor reaches clinical detectability, it contains around 108-109 cells. However, during tumor formation, significant cell loss occurs due to cell death. In some estimates, it could take up to a thousand cell generations, over a ~ 20-year life-span of a tumor, to reach clinical detectability, which would correspond to a "theoretical" generation of ~1030 cells. These rough calculations indicate that cancers are under negative selection. The fact that they thrive implies that they "evolve", and that their evolutionary trajectories are shaped by the pressure of the environment. Evolvability of a cancer is a function of its heterogeneity, which could be at the genetic, epigenetic, and ecological/microenvironmental levels [1]. These principles were summarized in a proposed classification in which Evo (evolutionary) and Eco (ecological) indexes are used to label cancers [1]. The Evo index addresses cancer cell-autonomous heterogeneity (genetic/epigenetic). The Eco index describes the ecological landscape (non-cell-autonomous) in terms of hazards to cancer survival and resources available. The reciprocal influence of Evo and Eco components is critical, as it can trigger self-sustaining loops that shape cancer evolvability [2]. Among the various hallmarks of cancer [3], metabolic alterations appear unique in that they intersect with both Evo and Eco components. This is partly because altered metabolism leads to the accumulation of oncometabolites. These oncometabolites have traditionally been viewed as mediators of non-cell-autonomous alterations in the cancer microenvironment. However, they are now increasingly recognized as inducers of genetic and epigenetic modifications. Thus, oncometabolites are uniquely positioned at the crossroads of genetic, epigenetic and ecological alterations in cancer. In this review, the mechanisms of action of oncometabolites will be summarized, together with their roles in the Evo and Eco phenotypic components of cancer evolvability. An evolutionary perspective of the impact of oncometabolites on the natural history of cancer will be presented.

Targeting the tumor microenvironment with biomaterials for enhanced immunotherapeutic efficacy

The tumor microenvironment (TME) is a complex system characterized by low oxygen, low pH, high pressure, and numerous growth factors and protein hydrolases that regulate a wide range of biological behaviors in the tumor and have a profound impact on cancer progression. Immunotherapy is an innovative approach to cancer treatment that activates the immune system, resulting in the spontaneous killing of tumor cells. However, the therapeutic efficacy of these clinically approved cancer immunotherapies (e.g., immune checkpoint blocker (ICB) therapies and chimeric antigen receptor (CAR) T-cell therapies) is far from satisfactory due to the presence of immunosuppressive TMEs created in part by tumor hypoxia, acidity, high levels of reactive oxygen species (ROS), and a dense extracellular matrix (ECM). With continuous advances in materials science and drug-delivery technologies, biomaterials hold considerable potential for targeting the TME. This article reviews the advances in biomaterial-based targeting of the TME to advance our current understanding on the role of biomaterials in enhancing tumor immunity. In addition, the strategies for remodeling the TME offer enticing advantages; however, the represent a double-edged sword. In the process of reshaping the TME, the risk of tumor growth, infiltration, and distant metastasis may increase.

Prediction of prognosis and immune response in lung adenocarcinoma based on mitophagy and lactate-related gene signatures

BACKGROUND

Lung adenocarcinoma (LUAD) causes leading death worldwide. Mitophagy and lactate metabolism accumulation are distinctive features of LUAD. We aimed to identify lactate-related genes (LRGs) signatures based on mitophagy for predicting prognosis and immune response in LUAD.

METHODS

The gene expression and clinical data were downloaded from TCGA and GEO database. First, the subtype analysis was analyzed based on 29 mitophagy genes. Survival, immune, and function differences between the different subtypes were analyzed. Then, based on mitophagy genes and 14 LRGs, the best LRGs were screened to construct a risk score model and combined with clinical factors to establish a nomogram for predicting patient survival. Finally, the expression level and molecular function of the key candidate gene OGDH were verified by in vitro experiments.

RESULTS

All the LUAD samples were divided into 2 subtypes: sub1 and sub2. The sub2 possessed worse survival. Immune score, immune checkpoint genes, and human leucocyte antigen genes in sub1 were higher than in sub2. Six optimal mitophagy-related LRGs were used to construct a risk score model. A high-risk score indicates poorer survival, higher tumor mutation burden, and higher drug sensitivity. The nomogram was robust in predicting LUAD survival. The experiments in vitro showed that knockdown of OGDH inhibited the proliferation, migration and invasion in LUAD cells.

CONCLUSIONS

A nomogram based on the construction of the mitophagy-related lactate genes predicts prognosis and immune response in LUAD. These results could help with risk stratification and targeted therapy for LUAD.

Lactate: a rising star in tumors and inflammation

Lactate has been traditionally regarded as a mere byproduct of glycolysis or metabolic waste. However, an increasing body of literature suggests its critical role in regulating various physiological and pathological processes. Lactate is generally associated with hypoxia, inflammation, viral infections, and tumors. It performs complex physiological roles by activating monocarboxylate transporter (MCT) or the G protein-coupled receptor GPR81 across the cell membrane. Lactate exerts immunosuppressive effects by regulating the functions of various immune cells (such as natural killer cells, T cells, dendritic cells, and monocytes) and its role in macrophage polarization and myeloid-derived suppressor cell (MDSC) differentiation in the tumor microenvironment. Lactic acid has also recently been found to increase the density of CD8+ T cells, thereby enhancing the antitumor immune response. Acute or chronic inflammatory diseases have opposite immune states in the inflammatory disease microenvironment. Factors such as cell types, transcriptional regulators, ionic mediators, and the microenvironment all contribute to the diverse functions lactate exhibits. Herein, we reviewed the pleiotropic effects of lactate on the regulation of various functions of immune cells in the tumor microenvironment and under inflammatory conditions, which may help to provide new insights and potential targets for the diagnosis and treatment of inflammatory diseases and malignancies.

Nanomaterial-based regulation of redox metabolism for enhancing cancer therapy

Altered redox metabolism is one of the hallmarks of tumor cells, which not only contributes to tumor proliferation, metastasis, and immune evasion, but also has great relevance to therapeutic resistance. Therefore, regulation of redox metabolism of tumor cells has been proposed as an attractive therapeutic strategy to inhibit tumor growth and reverse therapeutic resistance. In this respect, nanomedicines have exhibited significant therapeutic advantages as intensively reported in recent studies. In this review, we would like to summarize the latest advances in nanomaterial-assisted strategies for redox metabolic regulation therapy, with a focus on the regulation of redox metabolism-related metabolite levels, enzyme activity, and signaling pathways. In the end, future expectations and challenges of such emerging strategies have been discussed, hoping to enlighten and promote their further development for meeting the various demands of advanced cancer therapies. It is highly expected that these therapeutic strategies based on redox metabolism regulation will play a more important role in the field of nanomedicine.

Emerging Role of Extracellular pH in Tumor Microenvironment as a Therapeutic Target for Cancer Immunotherapy

Identifying definitive biomarkers that predict clinical response and resistance to immunotherapy remains a critical challenge. One emerging factor is extracellular acidosis in the tumor microenvironment (TME), which significantly impairs immune cell function and contributes to immunotherapy failure. However, acidic conditions in the TME disrupt the interaction between cancer and immune cells, driving tumor-infiltrating T cells and NK cells into an inactivated, anergic state. Simultaneously, acidosis promotes the recruitment and activation of immunosuppressive cells, such as myeloid-derived suppressor cells and regulatory T cells (Tregs). Notably, tumor acidity enhances exosome release from Tregs, further amplifying immunosuppression. Tumor acidity thus acts as a "protective shield," neutralizing anti-tumor immune responses and transforming immune cells into pro-tumor allies. Therefore, targeting lactate metabolism has emerged as a promising strategy to overcome this barrier, with approaches including buffer agents to neutralize acidic pH and inhibitors to block lactate production or transport, thereby restoring immune cell efficacy in the TME. Recent discoveries have identified genes involved in extracellular pH (pHe) regulation, presenting new therapeutic targets. Moreover, ongoing research aims to elucidate the molecular mechanisms driving extracellular acidification and to develop treatments that modulate pH levels to enhance immunotherapy outcomes. Additionally, future clinical studies are crucial to validate the safety and efficacy of pHe-targeted therapies in cancer patients. Thus, this review explores the regulation of pHe in the TME and its potential role in improving cancer immunotherapy.

Analysis of immune status and prognostic model incorporating lactic acid metabolism-associated genes

BACKGROUND

Cancer development is intricately linked with metabolic dysregulation, including lactic acid metabolism, which plays a pivotal role in tumor progression and immune evasion. However, its specific implications in gastric adenocarcinoma (STAD) remain unclear. This study introduces a novel methodology to evaluate lactic acid metabolism comprehensively in STAD, aiming to elucidate its prognostic significance and impact on immunotherapy efficacy. Targeted therapies directed at key lactic acid metabolism genes (LMGs) identified within the tumor microenvironment (TME) hold promise for personalized treatment strategies.

METHODS

Lactic acid metabolism patterns were assessed in 415 STAD patients using a panel of 21 LMGs. Cox regression and Lasso regression analyses were employed to develop a predictive risk model based on differentially expressed genes (DEGs). Validation of the model was conducted using independent cohorts from the GEO and TCGA databases, as well as additional datasets focused on immunotherapy responses. Further investigations into TME dynamics of lactic acid metabolism included functional assays targeting SLC16A3, a pivotal gene identified through our analyses.

RESULTS

Patients were stratified into distinct risk groups based on their lactic acid metabolism profiles. Low-risk patients exhibited attenuated lactic acid metabolism, correlating with favorable clinical outcomes characterized by prolonged survival and enhanced responsiveness to immunotherapy. Notably, tumor cells within the TME demonstrated heightened levels of active lactic acid metabolism, particularly impacting tumor-infiltrating lymphocytes such as CD8 + T cells and regulatory T cells. Mechanistically, SLC16A3 emerged as a critical regulator promoting STAD cell proliferation, invasion, and migration while modulating the metabolic landscape.

CONCLUSION

This study underscores the prognostic value of a lactic acid metabolism-based model in STAD, providing insights into its potential as a predictive biomarker for patient stratification and therapeutic targeting. The findings highlight SLC16A3 as a promising candidate for therapeutic intervention aimed at modulating lactic acid metabolism in the TME, thereby advancing personalized treatment strategies in gastric cancer management.

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.

A Bimetallic Nanomodulator to Reverse Immunosuppression via Sonodynamic-Ferroptosis and Lactate Metabolism Modulation

Triple-negative breast cancer (TNBC) responds poorly to immunotherapy due to insufficient immunogenicity and highly immunosuppressive tumor microenvironment (TME). Herein, an intelligent calcium/cobalt-based nanomodulator (Ca,Co)CO3-LND-TCPP@F127-TA (abbreviated as CCLT@FT) is developed to act as a sonodynamic-ferroptosis inducer and metabolic immunoadjuvant to enhance anti-tumor immunotherapy. More details, simultaneous reactive oxygen species (ROS) generation and glutathione (GSH) depletion can be achieved due to the existence of Co2+/Co3+ redox couple in CCLT@FT. Meanwhile, mitochondrial Ca2+ overload and tetrakis(4-carboxyphenyl) porphyrin (TCPP)-mediated sonodynamic therapy (SDT) further amplify the oxidative stress and promote ferroptosis in tumor cells. More impressively, CCLT@FT can modulate lactate metabolism by doping with cobalt and loading with lonidamine (LND, an inhibitor of MCT4), thereby reversing the high-lactate immunosuppressive TME. Furthermore, the combination with immune checkpoint blockade (ICB) therapy is found to achieve superior anti-tumor immunity, which in turn promotes ferroptosis of tumor cells by downregulating SLC7A11 protein, ultimately creating a "cycle" therapy. Overall, this work demonstrates a novel strategy for enhancing anti-tumor immunotherapy based on a closed-loop enhancement therapeutic route between CCLT@FT inducing ferroptosis/lactate metabolism modulation and ICB therapy, providing an alternative and important reference for effective immunotherapy of TNBC.

Admission albumin-globulin ratio associated with delayed cerebral ischemia following aneurysmal subarachnoid hemorrhage

Background

Despite the widespread use in ischemic stroke, cancer, and malnutrition, the predictive ability of serum albumin to globulin ratio (A/G) among patients suffering from aneurysmal subarachnoid hemorrhage (aSAH) remains unknown. This study aimed to determine if serum A/G ratio is associated with the occurrence of delayed cerebral ischemia (DCI) after aSAH.

Methods

We retrospectively viewed the medical records of aSAH patients from 08/2017 to 08/2022. Serum albumin and globulin laboratory test results were collected within 24 hours after admission. Serum A/G were dichotomized based on whether the DCI occurred. Logistic regression was used to determine the predictors of DCI. The relationship between serum A/G and the occurrence of DCI was analyzed with receiver operating characteristic(ROC) curve.

Results

A total of 363 eligible patients with aSAH were included in the study, among which DCI occurred in 87 patients(23.97%). Serum A/G[OR=2.720, 95%CI (1.190-6.270), P=0.018], non-surgical[OR=0.228, 95%CI (0.065-0.621), P=0.008], lactate dehydrogenase[OR=1.004, 95%CI (1.000-1.008), P=0.029], P[OR=0.354, 95%CI (0.130-0.926), P=0.038], plasma fibrinogen[OR=1.266, 95%CI (1.019-1.583), P=0.035] were associated with the occurrence of DCI. ROC showed that serum A/G, non-surgical, LDH, P, plasma fibrinogen could predict the occurrence of DCI in aSAH patients with values 0.575, 0.560, 0.602, 0.571 and 0.539 for serum A/G, non-surgical, LDH, P, plasma fibrinogen, respectively.

Conclusions

In conclusion, serum A/G levels are correlated with DCI in individuals with aSAH, and high serum A/G levels on admission may be associated with the occurrence of DCI.

Engineering Stimuli-Responsive Materials for Precision Medicine

Over the past decade, precision medicine has garnered increasing attention, making significant strides in discovering new therapeutic drugs and mechanisms, resulting in notable achievements in symptom alleviation, pain reduction, and extended survival rates. However, the limited target specificity of primary drugs and inter-individual differences have often necessitated high-dosage strategies, leading to challenges such as restricted deep tissue penetration rates and systemic side effects. Material science advancements present a promising avenue for these issues. By leveraging the distinct internal features of diseased regions and the application of specific external stimuli, responsive materials can be tailored to achieve targeted delivery, controllable release, and specific biochemical reactions. This review aims to highlight the latest advancements in stimuli-responsive materials and their potential in precision medicine. Initially, we introduce disease-related internal stimuli and capable external stimuli, elucidating the reaction principles of responsive functional groups. Subsequently, we provide a detailed analysis of representative pre-clinical achievements of stimuli responsive materials across various clinical applications, including enhancements in the treatment of cancers, injury diseases, inflammatory diseases, infection diseases, and high-throughput microfluidic biosensors. Finally, we discuss some clinical challenges, such as off-target effects, long-term impacts of nano-materials, potential ethical concerns, and offer insights into future perspectives of stimuli-responsive materials.

New insights into the roles of lactylation in cancer

Lactylation, a novel discovered posttranslational modification, is a vital component of lactate function and is prevalent in a wide range of cells, interacting with both histone and non-histone proteins. Recent studies have confirmed that lactylation as a new contributor to epigenetic landscape is involved in multiple pathological processes. Accumulating evidence reveals that lactylation exists in different pathophysiological states and leads to inflammation and cancer; however, few mechanisms of lactylation have been elaborated. This review summarizes the biological processes and pathophysiological roles of lactylation in cancer, as well as discusses the relevant mechanisms and potential therapeutic targets, aiming to provide new insights for targeted cancer therapy.

Role of tumor-derived exosomes mediated immune cell reprograming in cancer

Tumor-derived exosomes (TDEs), as topologies of tumor cells, not only carry biological information from the mother, but also act as messengers for cellular communication. It has been demonstrated that TDEs play a key role in inducing an immunosuppressive tumor microenvironment (TME). They can reprogram immune cells indirectly or directly by delivering inhibitory proteins, cytokines, RNA and other substances. They not only inhibit the maturation and function of dendritic cells (DCs) and natural killer (NK) cells, but also remodel M2 macrophages and inhibit T cell infiltration to promote immunosuppression and create a favorable ecological niche for tumor growth, invasion and metastasis. Based on the specificity of TDEs, targeting TDEs has become a new strategy to monitor tumor progression and enhance treatment efficacy. This paper reviews the intricate molecular mechanisms underlying the immunosuppressive effects induced by TDEs to establish a theoretical foundation for cancer therapy. Additionally, the challenges of TDEs as a novel approach to tumor treatment are discussed.

Multi-stage mechanisms of tumor metastasis and therapeutic strategies

The cascade of metastasis in tumor cells, exhibiting organ-specific tendencies, may occur at numerous phases of the disease and progress under intense evolutionary pressures. Organ-specific metastasis relies on the formation of pre-metastatic niche (PMN), with diverse cell types and complex cell interactions contributing to this concept, adding a new dimension to the traditional metastasis cascade. Prior to metastatic dissemination, as orchestrators of PMN formation, primary tumor-derived extracellular vesicles prepare a fertile microenvironment for the settlement and colonization of circulating tumor cells at distant secondary sites, significantly impacting cancer progression and outcomes. Obviously, solely intervening in cancer metastatic sites passively after macrometastasis is often insufficient. Early prediction of metastasis and holistic, macro-level control represent the future directions in cancer therapy. This review emphasizes the dynamic and intricate systematic alterations that occur as cancer progresses, illustrates the immunological landscape of organ-specific PMN creation, and deepens understanding of treatment modalities pertinent to metastasis, thereby identifying some prognostic and predictive biomarkers favorable to early predict the occurrence of metastasis and design appropriate treatment combinations.

How lactate affects immune strategies in lymphoma

Tumor cells undergo metabolic reprogramming through shared pathways, resulting in a hypoxic, acidic, and highly permeable internal tumor microenvironment (TME). Lactate, once only regarded as a waste product of glycolysis, has an inseparable dual role with tumor immunity. It can not only provide a carbon source for immune cells to enhance immunity but also help the immune escape through a variety of ways. Lymphoma also depends on the proliferation signal of TME. This review focuses on the dynamic process of lactate metabolism and immune function changes in lymphoma and aims to comprehensively summarize and explore which genes, transcription factors, and pathways affect the biological changes and functions of immune cells. To deeply understand the complex and multifaceted role of lactate metabolism and immunity in lymphoma, the combination of lactate targeted therapy and classical immunotherapy will be a promising development direction in the future.

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.

Prognostic value of a lactate metabolism gene signature in lung adenocarcinoma and its associations with immune checkpoint blockade therapy response

Lung adenocarcinoma (LUAD) is a study that examines the prognostic value of lactate metabolism genes in tumor cells, which are associated with clinical prognosis. We analyzed the expression and clinical data for LUAD from The Cancer Genome Atlas database, using the GSE68465 dataset from the Gene Expression Omnibus and the MSigDB database. LASSO Cox regression and stepwise Cox regression were used to identify the optimal lactate metabolism gene signature. Differences in immune infiltration, tumor mutation burden (TMB), and response to immune checkpoint blockade (ICB) therapy were evaluated between groups. LASSO and Cox regression analyses showed an eight-lactate metabolism gene signature for model construction in both TCGA cohort and GSE68465 data, with higher survival outcomes in high-risk groups. The lactate metabolism risk score had an independent prognostic value (hazard ratio: 2.279 [1.652-3.146], P < .001). Immune cell infiltration differed between the risk groups, such as CD8+ T cells, macrophages, dendritic cells, mast cells, and neutrophils. The high-risk group had higher tumor purity, lower immune and stromal scores, and higher TMB. High-risk samples had high tumor immune dysfunction and exclusion (TIDE) scores and low cytolytic activity (CYT) scores, indicating a poor response to ICB therapy. Similarly, most immune checkpoint molecules, immune inhibitors/stimulators, and major histocompatibility complex (MHC) molecules were highly expressed in the high-risk group. The 8-lactate metabolism gene-based prognostic model predicts patient survival, immune infiltration, and ICB response in patients with LUAD, driving the development of therapeutic strategies to target lactate metabolism.

A "lysosomal bomb" constructed based on amorphous calcium carbonate to induce tumor apoptosis by amplified sonodynamic therapy

The acidic nature of malignant tumors leads to increased drug sequestration and the evasion of apoptotic damage, which is further exacerbated by abnormal lysosomes in tumor cells. In this study, a "lysosomal bomb" will be constructed using a type of acid-neutralized amorphous calcium carbonate (ACC) to encapsulate the sonosensitizer protoporphyrin IX (PpIX), and then coated with homologous tumor cell membranes to increase water solubility and homologous targeting. The PpIX-ACC@CMs designed in this paper are popcorn-like structures, which can not only neutralize the tumor's acidic microenvironment to balance the pH value and release excess Ca2+, but also cause lysosomal dysfunction and achieve drug lysosomal escape to increase drug accumulation. Additionally, the CO2 gas nucleus produced by the acid reaction of ACC can increase the ultrasonic cavitation effect to amplify the sonodynamic therapy (SDT) effect. In vitro and in vivo experiments demonstrated that PpIX-ACC@CMs, serving as a "lysosomal bomb," successfully localized to lysosomes of tumor cells and exhibited lysosomal escape ability through its acid reaction ability, achieving excellent SDT efficacy under ultrasound stimulation. Furthermore, exogenous Ca2+ overload also increased the likelihood of tumor calcification, which could contribute to in vivo tumor inhibition and facilitate CT medical imaging to monitor treatment efficacy.

Lysine lactylation-based insight to understanding the characterization of cervical cancer

Lysine lactylation (Kla), a recently discovered post-translational modification (PTM), is not only present in histone proteins but also widely distributed among non-histone proteins in tumor cells and immunocytes. However, the precise characterization and functional implications of these non-histone Kla proteins remain to be explored. Herein, a comprehensive proteomic analysis of Kla was conducted in HeLa cells. As a result, a total of 3633 Kla sites on 1637 proteins were identified. Subsequently, the stable Kla substrates were obtained and sorted to investigate the characterization and function of Kla proteins. Moreover, we characterized the Kla-related features of cervical cancers through integrative analyses of multiple datasets with proteomes, transcriptomes and single-cell transcriptome profiling. Kla-related genes (KRGs) were used to stratify cervical cancers into two clusters (C1 and C2). C2 cluster display inhibition in glycosylation and increased oxidative phosphorylation activity with high survival rate. In addition, we constructed a prognostic model based on two lactate signature genes, namely ISY1 and PPP1R14B. Interestingly, our findings revealed a negative correlation between PPP1R14B expression and the infiltration of CD8+ T cells, as well as a lower survival rate. This observation was further validated at the single-cell resolution. Simultaneously, we found that K140R mutant of PPP1R14B resulted in the decrease of Kla level and enhanced the proliferation and migration capabilities of cervical cancer cell lines, suggesting PPP1R14B-K140la has an effect on tumor behaviors. Collectively, we provides a Kla-based insight to understanding the characterization of cervical cancer, offering a potential avenue for therapeutic approaches.

AARS1 and AARS2 sense L-lactate to regulate cGAS as global lysine lactyltransferases

L-lactate modifies proteins through lactylation1, but how this process occurs is unclear. Here we identify the alanyl-tRNA synthetases AARS1 and AARS2 (AARS1/2) as intracellular L-lactate sensors required for L-lactate to stimulate the lysine lactylome in cells. AARS1/2 and the evolutionarily conserved Escherichia coli orthologue AlaRS bind to L-lactate with micromolar affinity and they directly catalyse L-lactate for ATP-dependent lactylation on the lysine acceptor end. In response to L-lactate, AARS2 associates with cyclic GMP-AMP synthase (cGAS) and mediates its lactylation and inactivation in cells and in mice. By establishing a genetic code expansion orthogonal system for lactyl-lysine incorporation, we demonstrate that the presence of a lactyl moiety at a specific cGAS amino-terminal site abolishes cGAS liquid-like phase separation and DNA sensing in vitro and in vivo. A lactyl mimetic knock-in inhibits cGAS, whereas a lactyl-resistant knock-in protects mice against innate immune evasion induced through high levels of L-lactate. MCT1 blockade inhibits cGAS lactylation in stressed mice and restores innate immune surveillance, which in turn antagonizes viral replication. Thus, AARS1/2 are conserved intracellular L-lactate sensors and have an essential role as lactyltransferases. Moreover, a chemical reaction process of lactylation targets and inactivates cGAS.

Oral Heterojunction Coupling Interventional Optical Fiber Mediates Synergistic Therapy for Orthotopic Rectal Cancer

Catalytic therapy has shown great potential for clinical application. However, conventional catalytic therapies rely on reactive oxygen species (ROS) as "therapeutic drugs," which have limitations in effectively inhibiting tumor recurrence and metastasis. Here, a biomimetic heterojunction catalyst is developed that can actively target orthotopic rectal cancer after oral administration. The heterojunction catalyst is composed of quatrefoil star-shaped BiVO4 (BVO) and ZnIn2S4 (ZIS) nanosheets through an in situ direct growth technique. Poly-norepinephrine and macrophage membrane coatings afford the biomimetic heterojunction catalyst (BVO/ZIS@M), which has high rectal cancer targeting and retention abilities. The coupled optical fiber intervention technology activates the multicenter coordination of five catalytic reactions of heterojunction catalysts, including two reduction reactions (O2→·O2 - and CO2→CO) and three oxidation reactions (H2O→·OH, GSH→GSSG, and LA→PA). These catalytic reactions not only induce immunogenic death in tumor cells through the efficient generation of ROS/CO and the consumption of GSH but also specifically lead to the use of lactic acid (LA) as an electron donor to improve catalytic activity and disrupt the LA-mediated immunosuppressive microenvironment, mediating synergistic catalysis and immunotherapy for orthotopic rectal cancer. Therefore, this optical fiber intervention triggered the combination of heterojunction catalytic therapy and immunotherapy, which exhibits prominent antitumor effects.

A rising star involved in tumour immunity: Lactylation

In recent years, continuous exploration worldwide has revealed that some metabolites produced during cellular and tissue metabolism can act as signalling molecules to exert different effects on the human body. These metabolites may act as cofactors for proteases or as post-translational modifications linked to proteins. Lactate, a traditional metabolite, is found at high levels in the tumour microenvironment (TME). Many studies have shown that lactate influences tumorigenesis and development via different mechanisms, not only through the metabolic reprogramming of tumours but also through its significant impact on tumour immunity. Previously, tumour cells were reported to use glucose and glutamine to fuel lactate metabolism; however, lactate serves not only as an energy source for tumour cells but also as a precursor substance needed for the post-translational modification of proteins. Recent studies identified a novel form of epigenetic modification, lactate-mediated histone lysine lactylation (Kla) and demonstrated that histone lactylation directly stimulates chromatin after gene transcription; consequently, lactylation has become a popular research topic in recent years. This article focuses on the research progress and application prospects of lactylation in the context of tumour immunity.

Targeting Lactate: An Emerging Strategy for Macrophage Regulation in Chronic Inflammation and Cancer

Lactate accumulation and macrophage infiltration are pivotal features of both chronic inflammation and cancer. Lactate, once regarded merely as an aftereffect of glucose metabolism, is now gaining recognition for its burgeoning spectrum of biological roles and immunomodulatory significance. Recent studies have evidenced that macrophages display divergent immunophenotypes in different diseases, which play a pivotal role in disease management by modulating macrophage polarization within the disease microenvironment. The specific polarization patterns of macrophages in a high-lactate environment and their contribution to the progression of chronic inflammation and cancer remain contentious. This review presents current evidence on the crosstalk of lactate and macrophage in chronic inflammation and cancer. Additionally, we provide an in-depth exploration of the pivotal yet enigmatic mechanisms through which lactate orchestrates disease pathogenesis, thereby offering novel perspectives to the development of targeted therapeutic interventions for chronic inflammation and cancer.

Lactate's impact on immune cells in sepsis: unraveling the complex interplay

Lactate significantly impacts immune cell function in sepsis and septic shock, transcending its traditional view as just a metabolic byproduct. This review summarizes the role of lactate as a biomarker and its influence on immune cell dynamics, emphasizing its critical role in modulating immune responses during sepsis. Mechanistically, key lactate transporters like MCT1, MCT4, and the receptor GPR81 are crucial in mediating these effects. HIF-1α also plays a significant role in lactate-driven immune modulation. Additionally, lactate affects immune cell function through post-translational modifications such as lactylation, acetylation, and phosphorylation, which alter enzyme activities and protein functions. These interactions between lactate and immune cells are central to understanding sepsis-associated immune dysregulation, offering insights that can guide future research and improve therapeutic strategies to enhance patient outcomes.

Euterpe oleracea Mart. Bioactive Molecules: Promising Agents to Modulate the NLRP3 Inflammasome

Inflammation is a vital mechanism that defends the organism against infections and restores homeostasis. However, when inflammation becomes uncontrolled, it leads to chronic inflammation. The NLRP3 inflammasome is crucial in chronic inflammatory responses and has become a focal point in research for new anti-inflammatory therapies. Flavonoids like catechin, apigenin, and epicatechin are known for their bioactive properties (antioxidant, anti-inflammatory, etc.), but the mechanisms behind their anti-inflammatory actions remain unclear. This study aimed to explore the ability of various flavonoids (isolated and combined) to modulate the NLRP3 inflammasome using in silico and in vitro models. Computer simulations, such as molecular docking, molecular dynamics, and MM/GBSA calculations examined the interactions between bioactive molecules and NLRP3 PYD. THP1 cells were treated with LPS + nigericin to activate NLRP3, followed by flavonoid treatment at different concentrations. THP1-derived macrophages were also treated following NLRP3 activation protocols. The assays included colorimetric, fluorometric, microscopic, and molecular techniques. The results showed that catechin, apigenin, and epicatechin had high binding affinity to NLRP3 PYD, similar to the known NLRP3 inhibitor MCC950. These flavonoids, particularly at 1 µg/mL, 0.1 µg/mL, and 0.01 µg/mL, respectively, significantly reduced LPS + nigericin effects in both cell types and decreased pro-inflammatory cytokine, caspase-1, and NLRP3 gene expression, suggesting their potential as anti-inflammatory agents through NLRP3 modulation.