Metabolic reprogramming, sensing, and cancer therapy

Metformin inhibits the progression of castration-resistant prostate cancer by regulating PDE6D induced purine metabolic alternation and cGMP / PKG pathway activation

The castration-resistant prostate cancer (CRPC) remains an incurable disease. Metformin has demonstrated a potential therapeutic effect on CRPC. However, the poor clinical performance of metformin against cancer may be due to its clinical dose being much lower than the anticancer concentration used in pre-clinical experiments. The challenge is to determine a way to enhance sensitivity to metformin at an appropriate concentration on CRPC. In this study, a mouse model of low-dose metformin treatment for CRPC cells were established. Metabolomic-seq and transcriptomic-seq was used to investigate changes in CRPC xenografts. We discovered that low-dose metformin inhibits the progression of CRPC by regulating PDE6D, which induces alterations in purine metabolism and activates the cGMP/PKG pathway. Furthermore, we found that cells with high expression of PDE6D were more resistant to metformin. When combined with the PDE6D inhibitor TMX-4100, the inhibitory effect on tumors was enhanced, and TMX-4100 demonstrated favorable biosafety in animal models. In conclusion, we found that low-dose metformin inhibits the progression of CRPC by regulating PDE6D-induced alterations in purine metabolism and activating the cGMP/PKG pathway. Moreover, patients with high PDE6D expression may exhibit greater resistance to metformin. Combining metformin with TMX-4100 could further improve the inhibitory effects on tumors.

Metabolic reprogramming of tumor microenviroment by engineered bacteria

The tumor microenvironment (TME) is a complex ecosystem that plays a crucial role in tumor progression and response to therapy. The metabolic characteristics of the TME are fundamental to its function, influencing not only cancer cell proliferation and survival but also the behavior of immune cells within the tumor. Metabolic reprogramming-where cancer cells adapt their metabolic pathways to support rapid growth and immune evasion-has emerged as a key factor in cancer immunotherapy. Recently, the potential of engineered bacteria in cancer immunotherapy has gained increasing recognition, offering a novel strategy to modulate TME metabolism and enhance antitumor immunity. This review summarizes the metabolic properties and adaptations of tumor and immune cells within the TME and summarizes the strategies by which engineered bacteria regulate tumor metabolism. We discuss how engineered bacteria can overcome the immunosuppressive TME by reprogramming its metabolism to improve antitumor therapy. Furthermore, we examine the advantages, potential challenges, and future clinical translation of engineered bacteria in reshaping TME metabolism.

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

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

Dual inhibition of oxidative phosphorylation and glycolysis using a hyaluronic acid nanoparticle NOX inhibitor enhanced response to radiotherapy in colorectal cancer

Metabolic reprogramming characterized by mitochondrial dysfunction and increased glycolysis is associated with aggressive tumor biology and poor therapeutic response. The interplays among NADPH oxidase (NOX)-mediated reactive oxygen species, regulation of glycolysis and oxidative phosphorylation (OXPHOS) in cancer cells suggest an opportunity to develop a new cancer therapy. We found that treatment with a hyaluronic acid nanoparticle encapsulated with GKT831 (HANP/GKT831), a NOX1/4 inhibitor, markedly inhibited the proliferation and invasion of cancer cells. Treated tumor cells had reduced levels of mitochondrial ROS, glycolysis, and OXPHOS. The combination of HANP/GKT831 with radiation reduced colony formation and invasion of tumor cells. The combination therapy markedly inhibited the levels of molecules in glycolysis, OXPHOS, and DNA repairing pathways in tumor cells. Systemic administrations of HANP/GKT831 combined with radiotherapy significantly inhibited tumor growth by 84.7 % in a mouse colorectal tumor model. Tumors treated with HANP/GKT831 and radiation had increased DNA damage and apoptotic cell death. Furthermore, the combined therapy increased intratumoral infiltration of activated cytotoxic T cells and M1 macrophages but reduced the levels of immunosuppressive fibroblasts and M2 macrophages. Our results support HANP/GKT831 as a cancer nanotherapeutic agent that induces redox and bioenergy stresses in cancer cells for enhanced therapeutic response to radiotherapy.

Tumor suppressing function of SLC16A7 in bladder cancer and its pan-cancer analysis

BACKGROUND

Bladder cancer (BCa), a prevalent malignancy of the urinary tract, is associated with high recurrence and mortality rates. SLC16A7, a member of the solute carrier family 16 (SLC16), encodes monocarboxylate transporters that are involved in the proton-coupled transport of metabolites, including lactate, pyruvate, and ketone bodies, across cell membranes. Evidence suggests that SLC16A7 exhibits variable expression in cancers and may influence tumor development, progression, and immune regulation. This study examined the role of SLC16A7 in cancer prognosis, progression, and immune regulation, focusing on BCa.

METHODS

A comprehensive analysis was conducted to evaluate the clinical and immunological relevance of SLC16A7 across multiple cancer types using data from 33 tumor datasets from 'The Cancer Genome Atlas (TCGA). ' Associations between SLC16A7 expression and clinicopathological features, prognostic indicators, tumor mutation burden (TMB), microsatellite instability (MSI), immune cell infiltration, and immune-related gene expression were systematically analyzed. Experimental validation was performed to assess SLC16A7 expression in the BCa tissues and cell lines. The prognostic value of SLC16A7 was confirmed using clinical follow-up data from an independent patient cohort. Functional studies included proliferation assays to investigate the effect of SLC16A7. CD8 + T cells were obtained from the peripheral blood of healthy donors and stimulated using CD3 and CD28 antibodies in combination with recombinant IL-2. To investigate the immunological role of SLC16A7, co-culture experiments were performed between BCa cells and activated CD8 + T cells. Additionally, CD8 + T cell chemotaxis assays and ELISA analyses were conducted to evaluate the immune responses mediated by SLC16A7.

RESULTS

SLC16A7 expression was downregulated in 16 cancer types, including BCa, and upregulated in three cancer types. Its expression was significantly associated with tumor stage in four cancers and showed both positive and negative correlations with prognosis, depending on the cancer type. Genomic analyses revealed significant associations between SLC16A7 and TMB in 13 cancer types and MSI in 11 cancer types. Pathway enrichment analyses (Hallmark-GSEA and KEGG-GSEA) indicated strong associations between SLC16A7, immune responses, and tumor progression. Immune infiltration analysis showed a predominantly positive association between SLC16A7 expression and immune cell infiltration, except in low-grade gliomas (LGG). CIBERSORT analysis demonstrated that SLC16A7 expression correlated positively with resting memory CD4 T cells, eosinophils, monocytes, resting mast cells, and memory B cells and negatively with activated memory CD4 T cells, M1 macrophages, follicular helper T cells, M0 macrophages, and CD8 T cells. SLC16A7 expression was also significantly associated with the expression of immune-regulatory molecules. Experimental validation showed reduced SLC16A7 expression in BCa tissues and cell lines compared to that in their normal counterparts. Kaplan-Meier survival analysis indicated that higher SLC16A7 expression was correlated with better overall survival in patients with BCa. Functional assays revealed that SLC16A7 inhibited BCa cell progression and promoted the chemotaxis and tumor-killing ability of CD8 + T cells in the BCa tumor microenvironment (TME).

CONCLUSIONS

SLC16A7 exhibits tumor-suppressive properties, with downregulation in most cancers, and is associated with favorable prognosis and enhanced immune responses. SLC16A7 functions as a tumor suppressor in BCa and is associated with improved survival outcomes. These findings suggest that SLC16A7 is a potential biomarker for cancer diagnosis and prognosis.

The Role of Intermittent Fasting in the Activation of Autophagy Processes in the Context of Cancer Diseases

Intermittent fasting (IF) is a dietary approach that influences key metabolic pathways, including autophagy-a crucial mechanism in maintaining cellular homeostasis. Autophagy plays a dual role in oncogenesis, acting both as a tumor suppressor and a survival mechanism under metabolic stress. IF has shown potential for reducing cancer risk and enhancing therapeutic efficacy by sensitizing tumor cells to chemotherapy and radiotherapy. However, its effects depend heavily on the type and stage of cancer. Potential risks, such as excessive weight loss and malnutrition, require careful evaluation. Further clinical studies are needed to optimize IF protocols as adjuncts to cancer therapy. This review discusses autophagy mechanisms induced by IF, their therapeutic implications in oncology, and the limitations of this dietary strategy.

Unraveling the immune evasion mechanisms in the tumor microenvironment of head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is a highly aggressive malignancy characterized by a complex tumor microenvironment (TME) that plays a pivotal role in tumor initiation, progression, and immune evasion. Recent advancements have highlighted the intricate interplay between immune cell infiltration patterns, immune checkpoint dysregulation, and metabolic reprogramming in driving HNSCC immune escape. Despite these insights, significant challenges remain, including the incomplete understanding of specific immune evasion pathways and the lack of personalized therapeutic strategies. To address these gaps, this review introduces a novel "Trinity" regulatory network of immune evasion in HNSCC, encompassing: (1) metabolic reprogramming-mediated immune checkpoint modulation, (2) stromal cell-driven immune dysfunction, and (3) epigenetic remodeling fostering immune tolerance. This framework provides a theoretical foundation for the development of multi-targeted combination therapies and offers innovative strategies to overcome immune evasion. Additionally, this review systematically synthesizes the current understanding of the relationship between the HNSCC microenvironment and immune escape, with a focus on emerging immunotherapeutic approaches such as PD-1/PD-L1 inhibitors and CAR-T cell therapy. Leveraging cutting-edge single-cell sequencing and spatial transcriptomics, we elucidate the spatiotemporal heterogeneity of the HNSCC immune landscape and propose a new paradigm of "lineage plasticity-driven immune adaptation." These insights not only advance our understanding of HNSCC biology but also pave the way for the development of precision immunotherapies aimed at improving patient survival and quality of life. By integrating multidisciplinary perspectives, this work underscores the importance of targeting the TME to achieve durable clinical responses and overcome immunotherapy resistance in HNSCC.

The role of the tumor microenvironment in HNSCC resistance and targeted therapy

The prognosis for head and neck squamous cell carcinoma (HNSCC) remains unfavorable, primarily due to significant therapeutic resistance and the absence effective interventions. A major obstacle in cancer treatment is the persistent resistance of cancer cells to a variety of therapeutic modalities. The tumor microenvironment (TME) which includes encompasses all non-malignant components and their metabolites within the tumor tissue, plays a crucial role in this context. The distinct characteristics of the HNSCC TME facilitate tumor growth, invasion, metastasis, and resistance to treatment. This review provides a comprehensive overview of the HNSCC TME components, with a particular focus on tumor-associated macrophages (TAMs), regulatory T cells (Tregs), myeloid-derived suppressor cells (MDSCs), cancer-associated fibroblasts (CAFs), the extracellular matrix, reprogrammed metabolic processes, and metabolic products. It elucidates their contributions to modulating resistance to chemotherapy, radiotherapy, targeted therapy, and immunotherapy in HNSCC, and explores novel therapeutic strategies targeting the TME for HNSCC management.

Unveiling the future of cancer stem cell therapy: a narrative exploration of emerging innovations

Cancer stem cells (CSCs), are a critical subpopulation within tumours, and are defined by their capacity for self-renewal, differentiation, and tumour initiation. These unique traits contribute to tumour progression, metastasis, and resistance to conventional treatments like chemotherapy and radiotherapy, often resulting in cancer recurrence and poor patient outcomes. As such, CSCs have become focal points in developing advanced cancer therapies. This review highlights progress in CSC-targeted treatments, including chimeric antigen receptor T-cell (CAR-T) therapy, immunotherapy, molecular targeting, and nanoparticle-based drug delivery systems. Plant-derived compounds and gene-editing technologies, such as clustered regularly interspaced short palindromic repeats (CRISPR), are explored for their potential to enhance precision and minimize side effects. Metabolic pathways integral to CSC survival, such as mitochondrial dynamics, mitophagy (regulated by dynamin-related protein 1 [DRP1] and the PINK1/Parkin pathway), one-carbon metabolism, amino acid metabolism (involving enzymes like glutaminase (GLS) and glutamate dehydrogenase (GDH]), lipid metabolism, and hypoxia-induced metabolic reprogramming mediated by hypoxia-inducible factors (HIF-1α and HIF-2α), are examined as therapeutic targets. The adaptability of CSCs through autophagy, metabolic flexibility, and epigenetic regulation by metabolites like α-ketoglutarate, succinate, and fumarate is discussed. Additionally, extracellular vesicles and nicotinamide adenine dinucleotide (NAD⁺) metabolism are identified as pivotal in redox balance, DNA repair, and epigenetic modifications. Addressing challenges such as tumour heterogeneity, immune evasion, and treatment durability requires interdisciplinary collaboration. Advancing CSC-targeted therapies is essential for overcoming drug resistance and preventing cancer relapse, paving the way for transformative cancer treatments. This review underscores the importance of leveraging innovative technologies and fostering collaboration to revolutionize cancer treatment.

The cGAS-STING pathway in cancer immunity: dual roles, therapeutic strategies, and clinical challenges

The cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway is a crucial component of the host's innate immunity and plays a central role in detecting cytosolic double-stranded DNA from endogenous and exogenous sources. Upon activation, cGAS synthesizes cGAMP, which binds to STING, triggering a cascade of immune responses, including the production of type I interferons and pro-inflammatory cytokines. In the context of cancers, the cGAS-STING pathway can exert dual roles: on the one hand, it promotes anti-tumor immunity by enhancing antigen presentation, stimulating T-cell responses, and inducing direct tumor cell apoptosis. On the other hand, chronic activation, particularly in tumors with chromosomal instability, can lead to immune suppression and tumor progression. Persistent cGAS-STING signaling results in the up-regulation of immune checkpoint molecules such as PD-L1, contributing to immune evasion and metastasis. Consequently, anti-tumor strategies targeting the cGAS-STING pathway have to consider the balance of immune activation and the immune tolerance caused by chronic activation. This review explores the mechanisms underlying both the anti-tumor and protumor roles of the cGAS-STING pathway, with a focus on potential therapeutic approaches, and the challenges faced in their clinical application, along with corresponding solutions.

Metabolic crossroads: unravelling immune cell dynamics in gastrointestinal cancer drug resistance

Metabolic reprogramming within the tumor microenvironment (TME) plays a critical role in driving drug resistance in gastrointestinal cancers (GI), particularly through the pathways of fatty acid oxidation and glycolysis. Cancer cells often rewire their metabolism to sustain growth and reshape the TME, creating conditions such as nutrient depletion, hypoxia, and acidity that impair antitumor immune responses. Immune cells within the TME also undergo metabolic alterations, frequently adopting immunosuppressive phenotypes that promote tumor progression and reduce the efficacy of therapies. The competition for essential nutrients, particularly glucose, between cancer and immune cells compromises the antitumor functions of effector immune cells, such as T cells. Additionally, metabolic by-products like lactate and kynurenine further suppress immune activity and promote immunosuppressive populations, including regulatory T cells and M2 macrophages. Targeting metabolic pathways such as fatty acid oxidation and glycolysis presents new opportunities to overcome drug resistance and improve therapeutic outcomes in GI cancers. Modulating these key pathways has the potential to reinvigorate exhausted immune cells, shift immunosuppressive cells toward antitumor phenotypes, and enhance the effectiveness of immunotherapies and other treatments. Future strategies will require continued research into TME metabolism, the development of novel metabolic inhibitors, and clinical trials evaluating combination therapies. Identifying and validating metabolic biomarkers will also be crucial for patient stratification and treatment monitoring. Insights into metabolic reprogramming in GI cancers may have broader implications across multiple cancer types, offering new avenues for improving cancer treatment.