bims-stacyt Biomed News
on Metabolism and the paracrine crosstalk between cancer and the organism
Issue of 2026–05–24
six papers selected by
Cristina Muñoz Pinedo, L’Institut d’Investigació Biomèdica de Bellvitge



  1. Acta Physiol (Oxf). 2026 Jun;242(6): e70260
      Solid tumors are characterized by profound metabolic and vascular abnormalities that generate a hostile tumor microenvironment (TME) marked by extracellular acidosis, hypoxia, and nutrient deprivation. While the consequences of these conditions for cancer cell behavior have been extensively studied, their impact on anti-tumor immune responses-particularly T cell function-has only recently gained attention. In this review, we summarize and critically discuss current knowledge on how acidic TME conditions affect the cytotoxic CD8+ T cells which are essential for anti-tumor immunity, and the protumorigenic, regulatory T cells (Tregs). An emerging body of literature shows that TME acidosis restricts cytotoxic CD8+ T cell motility and tumor penetration, suppresses cytokine production and secretion despite preserved transcription, impairs proliferation, and reduces cytotoxic killing capacity. These effects are closely linked to acid-induced metabolic reprogramming, including inhibition of glycolysis, altered mTOR and MYC signaling, and a shift toward fatty acid-dependent oxidative metabolism. In contrast, Tregs, which are metabolically adapted to rely on oxidative phosphorylation and lactate utilization, are comparatively resilient to acidic stress, and acidosis can enhance their suppressive capacity, thereby further skewing the immune balance toward tolerance. We highlight emerging evidence that tumor acidosis modulates immune checkpoint pathways, including pH-sensitive signaling through VISTA and regulation of PD-L1 expression, with important implications for immunotherapy sensitivity. We posit that limiting tumor acidosis may enable restoration of anti-tumor T cell function and improve therapeutic response to immune checkpoint blockade and adoptive T cell therapies.
    Keywords:  CD8+; Treg; anticancer immune response; cancer; immune oncology
    DOI:  https://doi.org/10.1111/apha.70260
  2. Clin Transl Med. 2026 May;16(5): e70665
      Immunotherapy has emerged as a transformative approach to cancer treatment, yet its clinical efficacy in most solid tumours remains limited, largely because of the immunosuppressive tumour microenvironment (TME). In this context, glucose metabolic reprogramming has emerged as a central determinant of tumour progression and immune dysfunction because it not only sustains the proliferative and biosynthetic demands of malignant cells but also profoundly reshapes immune responses within the TME. Effective antitumour immunity depends on the metabolic adaptability of effector immune cells, particularly the coordinated use of glycolysis and oxidative phosphorylation to support activation, expansion and cytotoxic function. Under the nutrient-deprived, hypoxic and acidic conditions that characterize the TME, however, these cells undergo metabolic restriction that progressively drives dysfunction and exhaustion. By contrast, regulatory T cells, tumour-associated macrophages and myeloid-derived suppressor cells exhibit greater metabolic plasticity, enabling their persistence and reinforcing their immunosuppressive activity. In this review, we discuss how glucose metabolic reprogramming drives immune dysfunction through several interconnected processes, including glucose competition, lactate accumulation, reciprocal regulation between glucose metabolism and cytokine signalling, glycosylation remodelling and dynamic crosstalk with immune checkpoint signalling. Collectively, these mechanisms position glucose metabolism as a pivotal immunometabolic axis linking tumour bioenergetics to immune evasion and therapeutic resistance. A deeper understanding of this regulatory network may inform the rational development of combination strategies that integrate metabolic intervention with immunotherapy, ultimately improving therapeutic precision and the durability of clinical benefit. HIGHLIGHT: Glucose metabolic reprogramming is a central driver of immunosuppression in the tumour microenvironment. Glucose competition establishes a selective bioenergetic hierarchy that constrains antitumour immunity. Lactate accumulation and reciprocal regulation with cytokine signalling amplify immunosuppressive signalling and reinforce immune exclusion. Glycosylation remodelling translates altered metabolic flux into sustained changes in receptor stability, ligand recognition and checkpoint responsiveness. Dynamic crosstalk with immune checkpoint signalling entrenches chronic immune dysfunction and therapeutic resistance.
    Keywords:  Warburg effect; glucose metabolic reprogramming; immunometabolism; immunosuppression; immunotherapy; tumour microenvironment
    DOI:  https://doi.org/10.1002/ctm2.70665
  3. Nature. 2026 May 20.
      L-2-Hydroxyglutarate (L-2-HG) is a low-abundance metabolite in mammals because the mitochondrial enzyme L-2-HG dehydrogenase (L2HGDH) oxidizes L-2-HG to 2-oxoglutarate (2-OG) to prevent its accumulation1. In humans, a lack of L2HGDH activity leads to L-2-HG accumulation and causes L-2-hydroxyglutaric aciduria2. Thus, L-2-HG is often classified as a toxic metabolite2-5. However, whether L-2-HG has any physiological function is unclear. Here we investigate whether L-2-HG qualifies as a physiological signalling metabolite by testing three criteria: regulated levels, defined molecular targets and a measurable physiological function. We report that an increase in mitochondrial NADH/NAD+ ratio drives malate dehydrogenase 2 (MDH2) to reduce 2-OG into L-2-HG. Moreover, L2HGDH oxidizes L-2-HG back to 2-OG in the mitochondrial matrix without requiring a functional electron transport chain. Through proteome integral solubility alteration assays, we show that the KDM4 family of H3K9 demethylases are L-2-HG-responsive targets. L-2-HG represses the nascent transcription of specific genes in mouse embryonic stem cells and increases H3K9me3 (a repressive histone mark) at these loci. In vivo, early embryonic L2HGDH overexpression in mice systemically reduces L-2-HG levels, impairs postnatal growth, causes mortality and produces selective functional and histological renal vulnerabilities. In postnatal kidneys, this reduction in L-2-HG causes H3K9me3 loss at L1MdTf retrotransposons and their derepression, which coincides with the activation of the integrated stress response and inflammation pathways. Our findings establish mitochondrial L-2-HG as a physiological signalling metabolite and indicate that metabolites previously regarded as toxic may also have crucial physiological functions.
    DOI:  https://doi.org/10.1038/s41586-026-10564-x
  4. J Biol Chem. 2026 May 15. pii: S0021-9258(26)02037-5. [Epub ahead of print] 113165
      O-linked β-N-acetylglucosamine (O-GlcNAc) functions as a nutrition rheostat to mediate cellular signaling pathways. It fluctuates in response to various nutritional factors, for instance, glucose availability. Previous investigations have shown that glucose deprivation upregulates O-GlcNAcylation levels. Meanwhile, starvation also activates autophagy, in particular, chaperone-mediated autophagy (CMA). But it is unknown what signal activates CMA during starvation. In the CMA pathway, heat shock cognate 70 kDa protein (HSC70) recognizes client proteins that bear a KFERQ pentapeptide motif, and delivers them for lysosomal degradation. Herein we show that glucose depletion increases both the affinity between HSC70 and O-GlcNAc transferase (OGT), and HSC70 O-GlcNAcylation levels. We validated that HSC70 is O-GlcNAcylated at T430 according to a previous chemoproteomic screen. We further demonstrate that O-GlcNAcylation attenuates HSC70 stability, but increases its binding with known CMA substrates, such as PKM2. We thus posit that starvation-induced HSC70 O-GlcNAcylation may activate CMA. To test this, we used label-free quantitative mass spectrometry to analyze HSC70-WT and HSC70-T430A interactome, and obtained a proteome-wide potential CMA substrate pool. By studying this dataset, we identified a new CMA substrate, Ataxin-10, a protein involved in a neurologic disorder. We then validated our model by mapping a potential KFERQ motif on Ataxin-10 and showing that HSC70-T430A decreased binding with Ataxin-10. In sum, our work suggests that CMA and O-GlcNAcylation intersect at HSC70, and starvation-induced O-GlcNAcylation of HSC70 is part of the signal that activates CMA during fasting.
    Keywords:  Ataxin-10; HSC70; O-GlcNAc; chaperone-mediated autophagy; starvation
    DOI:  https://doi.org/10.1016/j.jbc.2026.113165
  5. Cancer Res Commun. 2026 May 20.
      Pancreatic ductal adenocarcinoma (PDAC) is characterized by an immunosuppressive tumor microenvironment (TME) that limits the efficacy of immunotherapies. Many tumor-suppressive immune cells, including inflammatory macrophage subsets, rely on glycolysis to sustain effector function; however, the pancreatic TME is relatively glucose-limited. Here, we investigated whether increasing glucose availability in the periphery, which in turn translates to increased intratumoral glucose, could enhance immune-based therapies in PDAC. In vitro, glucose restriction induced metabolic reprogramming of inflammatory (M1-like) macrophages toward an oxidative, M2-like state with reduced inflammatory effector markers. In immunocompetent mice, administration of 30% dextrose drinking water increased both peripheral and intratumoral glucose levels and modestly shifted tumor transcriptional profiles toward a more inflammatory state without altering overall immune cell abundance. When macrophage-targeting immunotherapies (CSF1R inhibition with PLX3397 or CCR2 inhibition with PF-4136309) were combined with systemic hyperglycemia, tumors exhibited a pronounced increase in iNOS⁺ M1-like macrophages, a reduction in arginase⁺ M2-like macrophages, enhanced CD8⁺ T cell infiltration, and decreased abundance of tumor-associated fibroblasts. These immunotherapies improved overall survival in immunocompetent mice bearing orthotopic pancreatic tumors only when combined with hyperglycemia. Analyses of patient samples confirmed the presence of a favorable anti-tumor immune infiltrate with elevated glucose levels. Together, these findings identify glucose availability as a key regulator of macrophage polarization and immunotherapy efficacy in PDAC.
    DOI:  https://doi.org/10.1158/2767-9764.CRC-25-0338
  6. Neuro Oncol. 2026 May 21. pii: noag114. [Epub ahead of print]
       BACKGROUND: Brain metastasis (BM) is a leading cause of mortality in breast cancer patients. This study utilizes single-cell RNA sequencing (scRNA-seq) to identify high-risk malignant sub-clusters and uncover potential therapeutic targets driving BM.
    METHODS: Five pairs of scRNA-seq data of primary breast tumors (PT) and brain metastases (BM) were retrieved from the Gene Expression Omnibus (GEO) database. Following unsupervised clustering and cell-type annotation, specialized bioinformatic pipelines-including inferCNV and pseudotime trajectory analysis-were implemented to delineate malignant subpopulations and evolutionary states associated with high brain metastatic potential. Molecular mechanisms were investigated using ChIP-qPCR, nascent RNA labeling assay, and dual-luciferase assays. Clinical significance was evaluated in a 124 paired-patient cohort using propensity score matching (PSM), while in vivo metastatic potential was assessed via a murine carotid artery injection model.
    RESULTS: We identified a specific malignant epithelial sub-cluster (Cluster 3) characterized by high lactate levels and superior BM potential, and subsequently establishing CREB1 lactylation as a biomarker of this cluster. Mechanistically, LDHA-mediated lactylation of CREB1 at Lysine 136 (K136) enhances its transcriptional activity, upregulating cytoskeletal genes including CALML5, CNN2, and PDLIM1. This axis facilitates pseudopodia formation, cellular migration. In vivo, LDHA knockdown significantly reduced intracranial tumor burden. Clinically, high lactylation scores and high CALML5 expression are independent predictors of brain metastasis and overall survival.
    CONCLUSIONS: The LDHA-lactylation-CREB1-cytoskeleton axis is a novel driver of brain metastasis, serving as a promising therapeutic target and prognostic biomarker for breast cancer.
    Keywords:  brain metastasis; breast cancer; cytoskeletal remodeling; lactylation; scRNA-seq
    DOI:  https://doi.org/10.1093/neuonc/noag114