Glutaminase inhibition impairs CD8 T cell activation in STK11-/Lkb1-deficient lung cancer

Age- and diet-instructed metabolic rewiring of the tumor-immune microenvironment

The tumor-immune microenvironment (TIME) plays a critical role in tumor development and metastasis, as it influences the evolution of tumor cells and fosters an immunosuppressive state by intervening the metabolic reprogramming of infiltrating immune cells. Aging and diet significantly impact the metabolic reprogramming of the TIME, contributing to cancer progression and immune evasion. With aging, immune cell function declines, leading to a proinflammatory state and metabolic alterations such as increased oxidative stress and mitochondrial dysfunction, which compromise antitumor immunity. Similarly, dietary factors, particularly high-fat and high-sugar diets, promote metabolic shifts, creating a permissive TIME by fostering tumor-supportive immune cell phenotypes while impairing the tumoricidal activity of immune cells. In contrast, dietary restrictions have been shown to restore immune function by modulating metabolism and enhancing antitumor immune responses. Here, we discuss the intricate interplay between aging, diet, and metabolic reprogramming in shaping the TIME, with a particular focus on T cells, and highlight therapeutic strategies targeting these pathways to empower antitumor immunity.

A phase I/II study of the safety and efficacy of telaglenastat (CB-839) in combination with nivolumab in patients with metastatic melanoma, renal cell carcinoma, and non-small-cell lung cancer

BACKGROUND

Telaglenastat (CB-839) is a glutaminase 1 inhibitor that targets the dysregulation in glutamine metabolism in cancer cells and the tumor microenvironment. Preclinical data suggested that the combination of telaglenastat with programmed cell death protein 1 (PD-1) or programmed cell death-ligand 1 (PD-L1) antibodies can lead to enhanced immune response against cancer.

PATIENTS AND METHODS

We designed a phase I/II trial to investigate the safety and efficacy of telaglenastat combined with nivolumab in patients with advanced solid tumors. Dose escalation was carried out using a 3 + 3 design with two dose levels for telaglenastat (600 mg and 800 mg twice daily). Nivolumab was given at a fixed dose of 240 mg by intravenous infusion on days 1 and 15 of a 28-day cycle in all patients. Expansion in phase II was planned using Simon's two-stage design in disease- and prior therapy-specific cohorts.

RESULTS

We included a total of 118 patients across different cohorts. The most frequently reported adverse events were fatigue (42.4%; n = 50), nausea (39%; n = 46), and photophobia (32.2%; n = 38). In the response-assessable analysis set (including 107 patients in dose expansion and recommended phase II dose of dose escalation), the overall response rate (ORR) was 8.4% (n = 9). The ORR was 24% in 25 patients with clear-cell renal cell carcinoma (ccRCC) who were checkpoint inhibitor-naïve, 5.9% in 17 patients with ccRCC after nivolumab, 0% in 9 patients with ccRCC after other prior anti-PD-1/PD-L1, 5.4% in 37 patients with melanoma after anti-PD-1/PD-L1, and 0% in 19 patients with non-small-cell lung cancer after anti-PD-1/PD-L1.

CONCLUSIONS

Telaglenastat in combination with nivolumab was generally well tolerated. The combination did not show a pattern of efficacy across different study cohorts.

Methionine Metabolism Dictates PCSK9 Expression and Antitumor Potency of PD-1 Blockade in MSS Colorectal Cancer

Nutrient metabolisms are vitally interrelated to cancer progression and immunotherapy. However, the mechanisms by which nutrient metabolisms interact to remodel immune surveillance within the tumor microenvironment remain largely unexplored. Here it is demonstrated that methionine restriction inhibits the expression of proprotein convertase subtilisin/kexin type 9 (PCSK9), a key regulator of cholesterol homeostasis and a potential target for cancer immunotherapy, in colorectal cancer (CRC) but not in the liver. Mechanistically, methionine is catabolized to S-adenosylmethionine (SAM), promoting mRNA transcription of PCSK9 through increased DNA methyltransferase 1 (DNMT1)-mediated DNA methylation and suppression of sirtuin 6 (SIRT6) expression. Furthermore, both PCSK9 inhibition and dietary methionine restriction (DMR) potentiate PD-1 blockade therapy and foster the infiltration of CD8+ T cells in Colon 26 tumor-bearing mice-a proficient mismatch repair (pMMR)/microsatellite stable (MSS) CRC model that exhibits limited response to anti-PD-1 therapy. Moreover, combining 5-fluorouracil (5-FU) chemotherapy with PCSK9 inhibition and PD-1 blockade further augments therapeutic efficacy for MSS CRC. The findings establish a mechanistic link between amino acid metabolism and cholesterol metabolism within the tumor microenvironment where tumor cells sense methionine to regulate PCSK9 expression, highlighting promising combination therapeutic strategies that may greatly benefit MSS CRC patients.

Bionic gene delivery system activates tumor autophagy and immunosuppressive niche to sensitize anti-PD-1 treatment against STK11-mutated lung adenocarcinoma

Clinical data have shown that Serine/Threonine Kinase 11 (STK11) mutation may be associated with an immunosuppressive tumor microenvironment (ITEM) and poor prognosis and failure of anti-PD-1 (αPD1) treatment in non-small cell lung cancer (NSCLC). To explore the potential of restoring STK11 protein in immunotherapy, a bionic gene delivery system was prepared by coating the STK11-encoded DNA-cationic polymer complex core with the tumor cell membrane, termed STK11@PPCM. STK11@PPCM could specifically bind with NSCLC cells and achieve precise delivery of STK11-encoded DNA. The released DNA effectively restored the STK11 protein expression, consequently reactivating autophagy and immunogenic cell death (ICD) in cancer cells. The liberated damage-associated molecular patterns (DAMPs) and autophagosome induced dendritic cells (DCs) maturation, which in turn enhanced CD8 + T cell infiltration, M1 macrophage polarization, and proinflammatory factor expression, thereby reversing the ITEM. Moreover, STK11@PPCM was also found to improve the sensitivity of cancer cells to αPD1 by increasing the expression of PD-L1, which was confirmed in STK11-mutated NSCLC cell xenografted mouse models, constructed by CRISPR-Cas9 knockout technology. This work demonstrated for the first time that restoration of functional STK11 can effectively reverse ITME and boost αPD1 efficacy in NSCLC, offering a new therapeutic approach for STK11-mutated lung adenocarcinoma in clinic.

Advancing Cancer Treatment: A Review of Immune Checkpoint Inhibitors and Combination Strategies

A groundbreaking milestone in oncology has been the recognition and targeted elimination of malignant cells through cancer immunotherapy, which harnesses the body's immune system to attack cancer [...].

Amino acids in cancer: Understanding metabolic plasticity and divergence for better therapeutic approaches

Metabolic reprogramming is a hallmark of malignant transformation. While initial studies in the field of cancer metabolism focused on central carbon metabolism, the field has expanded to metabolism beyond glucose and glutamine and uncovered the important role of amino acids in tumorigenesis and tumor immunity as energy sources, signaling molecules, and precursors for (epi)genetic modification. As a result of the development and application of new technologies, a multifaceted picture has emerged, showing that context-dependent heterogeneity in amino acid metabolism exists between tumors and even within distinct regions of solid tumors. Understanding the complexity and flexibility of amino acid metabolism in cancer is critical because it can influence therapeutic responses and predict clinical outcomes. This overview discusses the current findings on the heterogeneity in amino acid metabolism in cancer and how understanding the metabolic diversity of amino acids can be translated into more clinically relevant therapeutic interventions.

Resistance in Lung Cancer Immunotherapy and How to Overcome It: Insights from the Genetics Perspective and Combination Therapies Approach

Lung cancer with the highest number of new cases diagnosed in Europe and in Poland, remains an example of malignancy with a very poor prognosis despite the recent progress in medicine. Different treatment strategies are now available for cancer therapy based on its type, molecular subtype and other factors including overall health, the stage of disease and cancer molecular profile. Immunotherapy is emerging as a potential addition to surgery, chemotherapy, radiotherapy or other targeted therapies, but also considered a mainstay therapy mode. This combination is an area of active investigation in order to enhance efficacy and overcome resistance. Due to the complexity and dynamic of cancer's ecosystem, novel therapeutic targets and strategies need continued research into the cellular and molecular mechanisms within the tumour microenvironment. From the genetic point of view, several signatures ranging from a few mutated genes to hundreds of them have been identified and associated with therapy resistance and metastatic potential. ML techniques and AI can enhance the predictive potential of genetic signatures and model the prognosis. Here, we present the overview of already existing treatment approaches, the current findings of key aspects of immunotherapy, such as immune checkpoint inhibitors (ICIs), existing molecular biomarkers like PD-L1 expression, tumour mutation burden, immunoscore, and neoantigens, as well as their roles as predictive markers for treatment response and resistance.

Glutamine's double-edged sword: fueling tumor growth and offering therapeutic hope

Tumor metabolic reprogramming is a highly complex process that enables tumor survival in the presence of limited nutrients, involving multiple signaling pathways, non-coding RNAs (ncRNAs), and transcription factors. Lately, glutamine has been found to enhance the growth, spread, and drug resistance of cancer cells, while also fostering an immunosuppressive microenvironment that aids tumor development. However, in some tumors, such as pancreatic cancer and melanoma, additional glutamine can inhibit the proliferation of tumor cells, and this mechanism is closely related to the regulation of the immune microenvironment. Therefore, further exploration of glutamine metabolism in tumors is essential for understanding the pathogenesis of cancer and for developing new metabolically targeted therapies. We systematically review the latest research on the reprogramming of glutamine metabolism and its role of tumor growth, spread, and immune system regulation. Additionally, we review the clinical research progress on targeted glutamine therapies and their application in combination with current anti-tumor treatments. Ultimately, we address the challenges and prospects involved in resistance to anti-cancer strategies aimed at glutamine metabolism.

Liver kinase B1 expression is associated with improved prognosis and tumor immune microenvironment features in small cell lung cancer

Background

Small cell lung cancer (SCLC) is characterized by early metastatic potential and poor prognosis. Liver kinase B1 (LKB1) is a tumor suppressor and a cell metabolism regulator. LKB1 downregulation has been associated with a cold tumor immune microenvironment (TIME). We aimed to analyze the role of LKB1 in SCLC in relation to its association with overall survival (OS) and TIME components.

Methods

We retrospectively evaluated SCLC patients consecutively treated at our institution from 1996 to 2020 with available tissue. LKB1, PD-L1 on tumor cells and on tumor immune-infiltrating cells, CD8, and FOXP3 were evaluated by immunohistochemistry (IHC), categorized according to predefined cutoffs. The primary endpoint was the description of LKB1 expression, and the secondary endpoints were the association with prognosis and TIME features.

Results

Tissue samples of 138 out of 481 SCLCs were adequate for molecular analyses. Eighty patients had limited stage (LS) at diagnosis and 58 had extended stage (ES). The median LKB1 IHC score was 4. Patients with IHC score >4 (n = 67) were classified as LKB1-positive. The probability of LKB1 positivity was higher in LS [odds ratio 2.78, 95% confidence interval (95% CI) 1.18-7.14]. At the data cutoff (2 January 2024), 123 patients died. The median OS (mOS) was 14.0 months (95% CI 11.5-19.4). mOS was significantly longer in patients with LKB1-positive expression [32.4 months (95% CI 13.6-62.4) vs. 11.2 months (95% CI 8.7-14.7); p < 0.001]. At multivariate analysis, positive LKB1 expression, LS, and no weight loss at diagnosis were confirmed as independent positive prognostic factors. TIME features were evaluated in 70 patients. Unexpectedly, LKB1-negative samples were more likely to show CD8+ tumor-infiltrating lymphocytes (TILs; p = 0.013). No association with PD-L1 expression nor the presence of FOXP3+ TILs was found.

Conclusion

LKB1 expression is a potential positive prognostic marker in SCLC. In this series, LKB1 expression was negatively associated with the presence of CD8+ TILs.

Health position paper and redox perspectives - Bench to bedside transition for pharmacological regulation of NRF2 in noncommunicable diseases

Nuclear factor erythroid 2-related factor 2 (NRF2) is a redox-activated transcription factor regulating cellular defense against oxidative stress, thereby playing a pivotal role in maintaining cellular homeostasis. Its dysregulation is implicated in the progression of a wide array of human diseases, making NRF2 a compelling target for therapeutic interventions. However, challenges persist in drug discovery and safe targeting of NRF2, as unresolved questions remain especially regarding its context-specific role in diseases and off-target effects. This comprehensive review discusses the dualistic role of NRF2 in disease pathophysiology, covering its protective and/or destructive roles in autoimmune, respiratory, cardiovascular, and metabolic diseases, as well as diseases of the digestive system and cancer. Additionally, we also review the development of drugs that either activate or inhibit NRF2, discuss main barriers in translating NRF2-based therapies from bench to bedside, and consider the ways to monitor NRF2 activation in vivo.

Tumor Microenvironment: Obstacles and Opportunities for T Cell-Based Tumor Immunotherapies

The complex composition and dynamic change of the tumor microenvironment (TME), mainly consisting of tumor cells, immune cells, stromal cells, and extracellular components, significantly impede the effector function of cytotoxic T lymphocytes (CTL), thus representing a major obstacle for tumor immunotherapies. In this review, we summarize and discuss the impacts and underlying mechanisms of major elements in the TME (different cell types, extracellular matrix, nutrients and metabolites, etc.) on the infiltration, survival, and effector functions of T cells, mainly CD8+ CTLs. Moreover, we also highlight recent advances that may potentiate endogenous antitumor immunity and improve the efficacy of T cell-based immunotherapies in patients with cancer by manipulating components inside/outside of the TME. A deeper understanding of the effects and action mechanisms of TME components on the tumor-eradicating ability of CTLs may pave the way for discovering new targets to augment endogenous antitumor immunity and for designing combinational therapeutic regimens to enhance the efficacy of tumor immunotherapies in the clinic.

Glutamine deprivation confers immunotherapy resistance by inhibiting IFN-γ signaling in cancer cells

Glutamine metabolism is emerging as a target for improving immunotherapy efficacy. However, the outcomes remain inconclusive. Given that the tumor-intrinsic response to interferon-γ (IFN-γ) is a key determinant of immunotherapy efficacy, we investigated whether and how glutamine deprivation in cancer cells affects their response to IFN-γ. By using human lung cancer cell lines, patient-derived tumor explants, and a syngeneic mouse model of lung cancer, we demonstrated that glutamine deprivation reduced the IFN-γ-driven response in cancer cells by promoting autophagy-dependent IFN-γ receptor (IFNGR1) degradation and rendering tumors resistant to anti-PD-1 or anti-PD-L1 therapy. Treatment with V9302, an inhibitor of the alanine-serine-cysteine transporter (ASCT2), enhanced the IFN-γ-driven response of cancer cells and increased the efficacy of PD-1 blockade therapy. Mechanistic analysis revealed that V9302 inhibited autophagy by impairing lysosomal activity independent of glutamine deprivation, likely because of its physiochemical properties, thereby preventing IFNGR1 degradation. Moreover, V9302 also increased Glut1 expression through the inhibition of lysosomal pathway-dependent degradation of Glut1 and consequently increased cancer cell glucose uptake, in turn retaining the levels of intracellular alpha-ketoglutarate (α-KG) and ATP, which are involved in maintaining IFN-γ signal transduction in cancer cells. In support of these findings, targeting lysosomal activity with chloroquine (CQ) also increased IFNGR1 expression and the IFN-γ-driven response in cancer cells. The administration of CQ increased the sensitivity of ASCT2-deficient tumors to anti-PD-L1 therapy. Glutamine deprivation per se leads to resistance to immunotherapy, whereas V9302 treatment results in increased immunotherapy efficacy through impaired lysosomal activity, which is independent of glutamine deprivation.

Integration of multiple machine learning approaches develops a gene mutation-based classifier for accurate immunotherapy outcomes

In addition to traditional biomarkers like PD-(L)1 expression and tumor mutation burden (TMB), more reliable methods for predicting immune checkpoint blockade (ICB) response in cancer patients are urgently needed. This study utilized multiple machine learning approaches on nonsynonymous mutations to identify key mutations that are most significantly correlated to ICB response. We proposed a classifier, Gene mutation-based Predictive Signature (GPS), to categorize patients based on their predicted response and clinical outcomes post-ICB therapy. GPS outperformed conventional predictors when validated in independent cohorts. Multi-omics analysis and multiplex immunohistochemistry (mIHC) revealed insights into tumor immunogenicity, immune responses, and the tumor microenvironment (TME) in lung adenocarcinoma (LUAD) across different GPS groups. Finally, we validated distinct responses of different GPS samples to ICB in an ex-vivo tumor organoid-PBMC co-culture model. Overall, our findings highlight a simple, robust classifier for accurate ICB response prediction, which could reduce costs, shorten testing times, and facilitate clinical implementation.

Metformin combined with CB-839 specifically inhibits KRAS-mutant ovarian cancer

KRAS mutations can cause metabolic reprogramming in ovarian cancer, leading to an increased metastatic capacity. This study investigated the metabolic reprogramming changes induced by KRAS mutations in ovarian cancer and the mechanism of action of metformin combined with a glutaminase 1 inhibitor (CB-839). KRAS-mutant ovarian cancer accounted for 14% of ovarian cancers. The expression of glucose metabolism-related (PFKFB3, HK2, GLUT1, and PDK2) and glutamine metabolism-related enzymes (GLS1 and ASCT2) was elevated in KRAS-mutant ovarian cancer cells compared with that in wild-type cells. KRAS-mutant cells had a higher aerobic oxidative capacity than did wild-type cells. Metformin inhibited proliferation, the expression of glucose metabolism-related enzymes, and the aerobic oxidative capacity of KRAS-mutant cells compared with those of control cells. Furthermore, it enhanced the expression of glutamine metabolism-related enzymes in KRAS-mutant cells. Metformin combined with CB-839 inhibited the proliferation and aerobic oxidation of KRAS-mutant cells to a greater extent than that observed in wild-type cells. Additionally, the inhibitory effects of metformin and CB-839 in the KRAS-mutant ovarian cancer NOD-SCID mouse model were significantly stronger than those in the drug-alone group. KRAS mutations lead to enhanced glucose and glutamine metabolism in ovarian cancer cells, which was inhibited by metformin combined with CB-839.

Multi-omics analysis reveals the sensitivity of immunotherapy for unresectable non-small cell lung cancer

Background

To construct a prediction model consisting of metabolites and proteins in peripheral blood plasma to predict whether patients with unresectable stage III and IV non-small cell lung cancer can benefit from immunotherapy before it is administered.

Methods

Peripheral blood plasma was collected from unresectable stage III and IV non-small cell lung cancer patients who were negative for driver mutations before receiving immunotherapy. Then we classified samples according to the follow-up results after two courses of immunotherapy and non-targeted metabolomics and proteomics analyses were performed to select different metabolites and proteins. Finally, potential biomarkers were picked out by applying machine learning methods including random forest and stepwise regression and prediction models were constructed by logistic regression.

Results

The presence of metabolites and proteins in peripheral blood plasma was causally associated with both non-small cell lung cancer and PD-L1/PD-1 expression levels. A total of 2 differential metabolites including 5-sulfooxymethylfurfural and Anthranilic acid and 2 differential proteins including Immunoglobulin heavy variable 1-45 and Microfibril-associated glycoprotein 4 were selected as reliable biomarkers. The area under the curve (AUC) of the prediction model built on clinical risks was merely 0.659. The AUC of metabolomics prediction model was 0.977 and the AUC of proteomics was 0.875 while the AUC of the integrative-omics prediction model was 0.955.

Conclusions

Metabolic and protein biomarkers in peripheral blood both have high efficacy and reliability in the prediction of immunotherapy sensitivity in unresectable stage III and IV non-small cell lung cancer, but validation in larger population-based cohorts is still needed.

Metabolic Singularities in Microsatellite-Stable Colorectal Cancer: Identifying Key Players in Immunosuppression to Improve the Immunotherapy Response

Although immune checkpoint inhibitor (ICI) therapy is currently the standard of care in microsatellite-unstable (MSI) metastatic colorectal cancer (CRC), ICI therapy, alone or in combination with other therapies, is not a treatment approach in microsatellite-stable (MSS) CRC, which is present in 95% of patients. In this review, we focus on metabolic singularities-at the transcriptomic (either bulk or single cell), proteomic, and post-translational modification levels-that induce immunosuppression in cancer and specifically in MSS CRC. First, we evaluate the current efficacy of ICIs in limited and metastatic disease in MSS CRC. Second, we discuss the latest findings on the potential biomarkers for evaluating ICI efficacy in MSS CRC using strict REMARK criteria. Third, we review the current evidence on metabolic patterns in CRC tumors and immune cell metabolism to advance our understanding of metabolic crosstalk and to pave the way for the development of combination strategies to enhance ICI efficacy.

Targeting glutamine metabolism crosstalk with tumor immune response

Glutamine, akin to glucose, is a fundamental nutrient for human physiology. Tumor progression is often accompanied by elevated glutamine consumption, resulting in a disrupted nutritional balance and metabolic reprogramming within the tumor microenvironment. Furthermore, immune cells, which depend on glutamine for metabolic support, may experience functional impairments and dysregulation. Although the role of glutamine in tumors has been extensively studied, the specific impact of glutamine competition on immune responses, as well as the precise cellular alterations within immune cells, remains incompletely understood. In this review, we summarize the consequences of glutamine deprivation induced by tumor-driven glutamine uptake on immune cells, assessing the underlying mechanisms from the perspective of various components of the immune microenvironment. Additionally, we discuss the potential synergistic effects of glutamine supplementation and immunotherapy, offering insights into future research directions. This review provides compelling evidence for the integration of glutamine metabolism and immunotherapy as a promising strategy in cancer therapy.

Predictive role of SLC1A5 in neuroblastoma prognosis and immunotherapy

BACKGROUND

Neuroblastoma, a prevalent extracranial solid tumor in pediatric patients, demonstrates significant clinical heterogeneity, ranging from spontaneous regression to aggressive metastatic disease. Despite advances in treatment, high-risk neuroblastoma remains associated with poor survival. SLC1A5, a key glutamine transporter, plays a dual role in promoting tumor growth and immune modulation. However, its contributions to neuroblastoma biology remain largely unexplored.

METHODS

This study utilized clinical neuroblastoma samples from 20 patients and 1310 cases from four public datasets to investigate SLC1A5 expression, biological function, and prognostic significance. Differential expression, Kaplan-Meier survival analysis, gene set enrichment analysis, and weighted correlation network analysis were conducted. Functional validation included qPCR, immunohistochemistry, Western blotting, and cell proliferation assays using the SLC1A5 inhibitor V-9302. A prognostic signature, SRPS, was constructed and validated using machine-learning approaches. Immune infiltration analysis was performed to evaluate the tumor immune microenvironment.

RESULTS

SLC1A5 expression was significantly elevated in high-risk neuroblastoma and correlated with advanced stages and poor prognosis. GSEA revealed mTORC1 signaling enrichment in high SLC1A5 expression groups, validated by increased p-p70S6K levels in tumor samples and neuroblastoma cells. V-9302 treatment suppressed mTORC1 signaling and inhibited cell proliferation. Hub-genes were identified to form the SRPS model, which demonstrated superior prognostic performance compared to existing models. Immune infiltration analysis revealed a more immunosuppressive tumor microenvironment associated with high SLC1A5 expression. Additionally, SLC1A5 negatively regulated ST8SIA1, a gene crucial for GD2 biosynthesis, suggesting that SLC1A5 inhibition may enhance GD2-directed immunotherapies.

CONCLUSION

SLC1A5 plays a pivotal role in neuroblastoma by promoting tumor progression and shaping an immunosuppressive microenvironment. The SRPS model, incorporating SLC1A5-associated genes, offers robust prognostic utility. Targeting SLC1A5 through advanced drug delivery systems and combined metabolic-immunotherapeutic strategies may enhance treatment specificity and efficacy. These findings provide a foundation for novel therapeutic approaches to improve outcomes in high-risk neuroblastoma patients.

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

OBJECTIVE

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

DESIGN

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

RESULTS

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

CONCLUSION

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

Divergent Clinical and Immunologic Outcomes Based on STK11 Co-mutation Status in Resectable KRAS-Mutant Lung Cancers Following Neoadjuvant Immune Checkpoint Blockade

PURPOSE

Co-mutations of the Kirsten rat sarcoma virus (KRAS) and serine/threonine kinase 11 (STK11) genes in advanced non-small cell lung cancer (NSCLC) are associated with immune checkpoint blockade (ICB) resistance. Although neoadjuvant chemoimmunotherapy is now a standard-of-care treatment for resectable NSCLC, the clinical and immunologic impacts of KRAS and STK11 co-mutations in this setting are unknown.

EXPERIMENTAL DESIGN

We evaluated and compared recurrence-free survival of resectable KRAS-mutated NSCLC tumors, with or without co-occurring STK11 mutations, treated with neoadjuvant ICB. Single-cell transcriptomics was performed on tumor-infiltrating T cells from seven KRASmut/STK11wt tumors and six KRAS and STK11 co-mutated (KRASmut/STK11mut) tumors.

RESULTS

Relative to KRASmut/STK11wt tumors, KRASmut/STK11mut exhibited significantly higher recurrence risk. Single-cell transcriptomics showed enhanced oxidative phosphorylation with evidence of decreased prostaglandin E2 signaling and increased IL-2 signaling in CD8+ tumor-infiltrating lymphocytes (TIL) from KRASmut/STK11mut tumors, a finding that was mirrored in KRASwt tumors that relapsed. TILs from KRASmut/STK11mut tumors expressed high levels of molecules associated with tumor residence, including CD39 and ZNF683 (HOBIT).

CONCLUSIONS

These divergent T-cell transcriptional fates suggest that T-cell maintenance and residence may be detrimental to antitumor immunity in the context of neoadjuvant ICB for resectable NSCLC, regardless of KRAS mutation status. Our work provides a basis for future investigations into the mechanisms underpinning prostaglandin E2 signaling and IL-2 signaling as they relate to T-cell immunity to cancer and to divergent clinical outcomes in KRASmut/STK11mut NSCLC treated with neoadjuvant ICB.

Pyrimidine synthesis enzyme CTP synthetase 1 suppresses antiviral interferon induction by deamidating IRF3

Metabolism is typically contextualized in conjunction with proliferation and growth. The roles of metabolic enzymes beyond metabolism-such as in innate immune responses-are underexplored. Using a focused short hairpin RNA (shRNA)-mediated screen, we identified CTP synthetase 1 (CTPS1), a rate-limiting enzyme of pyrimidine synthesis, as a negative regulator of interferon induction. Mechanistically, CTPS1 interacts with and deamidates interferon regulatory factor 3 (IRF3). Deamidation at N85 impairs IRF3 binding to promoters containing IRF3-responsive elements, thus muting interferon (IFN) induction. Employing CTPS1 conditional deletion and IRF3 deamidated or deamidation-resistant knockin mice, we demonstrated that CTPS1-driven IRF3 deamidation restricts IFN induction in response to viral infection in vivo. However, during immune activation, IRF3 deamidation by CTPS1 is inhibited by glycogen synthase kinase 3 beta (GSK3β) to promote IFN induction. This work demonstrates how CTPS1 tames innate immunity independent of its role in pyrimidine synthesis, thus expanding the functional repertoire of metabolic enzymes into immune regulation.

Inhibition of Glutamate-to-Glutathione Flux Promotes Tumor Antigen Presentation in Colorectal Cancer Cells

Colorectal cancer (CRC) cells display remarkable adaptability, orchestrating metabolic changes that confer growth advantages, pro-tumor microenvironment, and therapeutic resistance. One such metabolic change occurs in glutamine metabolism. Colorectal tumors with high glutaminase (GLS) expression exhibited reduced T cell infiltration and cytotoxicity, leading to poor clinical outcomes. However, depletion of GLS in CRC cells has minimal effect on tumor growth in immunocompromised mice. By contrast, remarkable inhibition of tumor growth is observed in immunocompetent mice when GLS is knocked down. It is found that GLS knockdown in CRC cells enhanced the cytotoxicity of tumor-specific T cells. Furthermore, the single-cell flux estimation analysis (scFEA) of glutamine metabolism revealed that glutamate-to-glutathione (Glu-GSH) flux, downstream of GLS, rather than Glu-to-2-oxoglutarate flux plays a key role in regulating the immune response of CRC cells in the tumor. Mechanistically, inhibition of the Glu-GSH flux activated reactive oxygen species (ROS)-related signaling pathways in tumor cells, thereby increasing the tumor immunogenicity by promoting the activity of the immunoproteasome. The combinatorial therapy of Glu-GSH flux inhibitor and anti-PD-1 antibody exhibited a superior tumor growth inhibitory effect compared to either monotherapy. Taken together, the study provides the first evidence pointing to Glu-GSH flux as a potential therapeutic target for CRC immunotherapy.

Glutamine metabolism is essential for coronavirus replication in host cells and in mice

Understanding the fundamental biochemical and metabolic requirements for the replication of coronaviruses within infected cells is of notable interest for the development of broad-based therapeutic strategies, given the likelihood of the emergence of new pandemic-potential virus species, as well as future variants of SARS-CoV-2. Here we demonstrate members of the glutaminase family of enzymes (GLS and GLS2), which catalyze the hydrolysis of glutamine to glutamate (i.e., the first step in glutamine metabolism), play key roles in coronavirus replication in host cells. Using a range of human seasonal and zoonotic coronaviruses, we show three examples where GLS expression increases during coronavirus infection of host cells, and another where GLS2 is upregulated. The viruses hijack the metabolic machinery responsible for glutamine metabolism to generate the building blocks for biosynthetic processes and satisfy the bioenergetic requirements demanded by the "glutamine addiction" of virus-infected cells. We demonstrate that genetic silencing of glutaminase enzymes reduces coronavirus infection and that newer members of two classes of allosteric inhibitors targeting these enzymes, designated as SU1, a pan-GLS/GLS2 inhibitor, and UP4, a specific GLS inhibitor, block viral replication in epithelial cells. Moreover, treatment of SARS-CoV-2 infected K18-human ACE2 transgenic mice with SU1 resulted in their complete survival compared to untreated control animals, which succumbed within 10 days post-infection. Overall, these findings highlight the importance of glutamine metabolism for coronavirus replication in human cells and mice and show that glutaminase inhibitors can block coronavirus infection and thereby may represent a novel class of broad-based anti-viral drug candidates.

The Role and Treatment Strategies of Ammonia-Related Metabolism in Tumor Microenvironment

Tumor cells achieve their adaptability through various metabolic reprogramming processes. Among them, ammonia, as a traditional metabolic waste, plays an increasingly important role in the tumor microenvironment along with its associated metabolites. Other cells in the microenvironment can also reshape the immune status of the microenvironment by regulating ammonia- related metabolism, and targeting this metabolic aspect has emerged as a potential strategy for tumor treatment. In this study, we have systematically reviewed the source and destination of ammonia in tumor cells, as well as the links between ammonia and other biological processes. We have also analyzed the ammonia-related metabolic regulation of other cells (including T cells, macrophages, dendritic cells, natural killer cells, myeloid-derived suppressor cells, and stromal cells) in the tumor microenvironment, and summarized the tumor treatment methods that target this metabolism. Through ammonia-related metabolic reprogramming, tumor cells obtain the energy they need for rapid growth and proliferation. Multiple immune cells and stromal cells in the microenvironment also interact with each other through this metabolic regulation, ultimately leading to immune suppression. Despite the heterogeneity of tumors and the complexity of cellular functions, further research into therapeutic interventions targeting ammonia-related metabolism is warranted. This review has focused on the role and regulation of ammonia-related metabolism in tumor cells and other cells in the microenvironment, and highlighted the efficacy and prospects of targeted ammonia- related metabolism therapy.

Metabolic immunoengineering approaches to enhance CD8+ T cell-based cancer immunotherapy

Many cancer immunotherapies rely on robust CD8+ T cells capable of eliminating cancer cells and establishing long-term tumor control. Recent insights into immunometabolism highlight the importance of nutrients and metabolites in T cell activation and differentiation. Within the tumor microenvironment (TME), CD8+ tumor-infiltrating lymphocytes (TILs) undergo metabolic adaptations to survive but compromise their effector function and differentiation. Targeting metabolism holds promise for enhancing CD8+ T cell-mediated antitumor immunity. Here, we overview the metabolic features of CD8+ TILs and their impact on T cell effector function and differentiation. We also highlight immunoengineering strategies by leveraging the Yin-Yang of metabolic modulation for improving cancer immunotherapy.

myCAF-derived exosomal PWAR6 accelerates CRC liver metastasis via altering glutamine availability and NK cell function in the tumor microenvironment

BACKGROUND

Liver metastasis from colorectal cancer (CRC) is a major clinical challenge that severely affects patient survival. myofibroblastic cancer-associated fibroblasts (myCAFs) are a major component of the CRC tumor microenvironment, where they contribute to tumor progression and metastasis through exosomes.

METHODS

Single-cell analysis highlighted a notable increase in myCAFs in colorectal cancer liver metastases (CRLM). Exosomal sequencing identified PWAR6 as the most significantly elevated lncRNA in these metastatic tissues. In vivo and in vitro assays confirmed PWAR6's roles in CRC cell stemness, migration, and glutamine uptake. RNA pulldown, RIP, and Co-IP assays investigated the molecular mechanisms of the PWAR6/NRF2/SLC38A2 signaling axis in CRC progression, flow cytometry was used to assess NK cell activity and cytotoxicity.

RESULTS

Clinically, higher PWAR6 expression levels are strongly associated with increased 68Ga FAPI-PET/CT SUVmax values, particularly in CRLM patients, where expression significantly exceeds that of non-LM cases and normal colon tissues. Regression analysis and survival data further support PWAR6 as a negative prognostic marker, with elevated levels correlating with worse patient outcomes. Mechanistically, PWAR6 promotes immune evasion by inhibiting NRF2 degradation through competitive binding with Keap1, thereby upregulating SLC38A2 expression, which enhances glutamine uptake in CRC cells and depletes glutamine availability for NK cells.

CONCLUSION

myCAFs derived exosomes PWAR6 represents a pivotal marker for CRC liver metastasis, and its targeted inhibition with ASO-PWAR6, in combination with FAPI treatment, effectively curtails metastasis in preclinical models, offering promising therapeutic potential for clinical management.

Inducing disulfidptosis in tumors:potential pathways and significance

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

CD98hc promotes drug resistance in extranodal natural killer/T cell lymphoma through tumor cell-derived small extracellular vesicles

Extranodal natural killer/T cell lymphoma (ENKTL) shows a high rate of recurrence after chemoradiotherapy. Drug resistance can be mediated by the cargo of small extracellular vesicles (sEVs). Here, we show that high abundance of the transmembrane glycoprotein CD98hc in tumor cells and serum sEVs was associated with ENKTL progression and drug resistance. Mechanistically, PEGylated-asparaginase (PEG-asp) treatment, a common therapy against ENKTL, promoted the translocation of the transcription factor ATF4 to the nucleus, where it was stabilized by USP1 and subsequently increased CD98hc expression. CD98hc delivered in tumor cell-derived sEVs increased tumor cell proliferation and drug resistance in a cultured human NK lymphoma cell line, animal models, and samples from patients with refractory/relapse ENKTL. Moreover, inhibiting both USP1 and EV secretion synergistically enhanced the cytotoxicity of PEG-asp. These data suggest that targeting CD98hc in the treatment of ENKTL may be beneficial in overcoming drug resistance.

The tRNA Gm18 methyltransferase TARBP1 promotes hepatocellular carcinoma progression via metabolic reprogramming of glutamine

Cancer cells rely on metabolic reprogramming to sustain the prodigious energetic requirements for rapid growth and proliferation. Glutamine metabolism is frequently dysregulated in cancers and is being exploited as a potential therapeutic target. Using CRISPR/Cas9 interference (CRISPRi) screening, we identified TARBP1 (TAR (HIV-1) RNA Binding Protein 1) as a critical regulator involved in glutamine reliance of cancer cell. Consistent with this discovery, TARBP1 amplification and overexpression are frequently observed in various cancers. Knockout of TARBP1 significantly suppresses cell proliferation, colony formation and xenograft tumor growth. Mechanistically, TARBP1 selectively methylates and stabilizes a small subset of tRNAs, which promotes efficient protein synthesis of glutamine transporter-ASCT2 (also known as SLC1A5) and glutamine import to fuel the growth of cancer cell. Moreover, we found that the gene expression of TARBP1 and ASCT2 are upregulated in combination in clinical cohorts and their upregulation is associated with unfavorable prognosis of HCC (hepatocellular carcinoma). Taken together, this study reveals the unexpected role of TARBP1 in coordinating the tRNA availability and glutamine uptake during HCC progression and provides a potential target for tumor therapy.

Reprogramming the immunosuppressive tumor microenvironment through nanomedicine: an immunometabolism perspective

Increasing evidence indicates that immunotherapy is hindered by a hostile tumor microenvironment (TME) featured with deprivation of critical nutrients and pooling of immunosuppressive metabolites. Tumor cells and immunosuppressive cells outcompete immune effector cells for essential nutrients. Meanwhile, a wide range of tumor cell-derived toxic metabolites exerts negative impacts on anti-tumor immune response, diminishing the efficacy of immunotherapy. Nanomedicine with excellent targetability offers a novel approach to improving cancer immunotherapy via metabolically reprogramming the immunosuppressive TME. Herein, we review recent strategies of enhancing immunotherapeutic effects through rewiring tumor metabolism via nanomedicine. Attention is drawn on immunometabolic tactics for immune cells and stromal cells in the TME via nanomedicine. Additionally, we discuss future directions of developing metabolism-regulating nanomedicine for precise and efficacious cancer immunotherapy.

Aerobic glycolysis but not GLS1-dependent glutamine metabolism is critical for anti-tumor immunity and response to checkpoint inhibition

Tumor cells undergo uncontrolled proliferation driven by enhanced anabolic metabolism including glycolysis and glutaminolysis. Targeting these pathways to inhibit cancer growth is a strategy for cancer treatment. Critically, however, tumor-responsive T cells share metabolic features with cancer cells, making them susceptible to these treatments as well. Here, we assess the impact on anti-tumor T cell immunity and T cell exhaustion by genetic ablation of lactate dehydrogenase A (LDHA) and glutaminase1 (GLS1), key enzymes in aerobic glycolysis and glutaminolysis. Loss of LDHA severely impairs expansion of T cells in response to tumors and chronic infection. In contrast, T cells lacking GLS1 can compensate for impaired glutaminolysis by engaging alternative pathways, including upregulation of asparagine synthetase, and thus efficiently respond to tumor challenge and chronic infection as well as immune checkpoint blockade. Targeting GLS1-dependent glutaminolysis, but not aerobic glycolysis, may therefore be a successful strategy in cancer treatment, particularly in combination with immunotherapy.

Glutamine Metabolism and Prostate Cancer

Glutamine (Gln) is a non-essential amino acid that is involved in the development and progression of several malignancies, including prostate cancer (PCa). While Gln is non-essential for non-malignant prostate epithelial cells, PCa cells become highly dependent on an exogenous source of Gln. The Gln metabolism in PCa is tightly controlled by well-described oncogenes such as MYC, AR, and mTOR. These oncogenes contribute to therapy resistance and progression to the aggressive castration-resistant PCa. Inhibition of Gln catabolism impedes PCa growth, survival, and tumor-initiating potential while sensitizing the cells to radiotherapy. Therefore, given its significant role in tumor growth, targeting Gln metabolism is a promising approach for developing new therapeutic strategies. Ongoing clinical trials evaluate the safety and efficacy of Gln catabolism inhibitors in combination with conventional and targeted therapies in patients with various solid tumors, including PCa. Further understanding of how PCa cells metabolically interact with their microenvironment will facilitate the clinical translation of Gln inhibitors and help improve therapeutic outcomes. This review focuses on the role of Gln in PCa progression and therapy resistance and provides insights into current clinical trials.

Necroptosis-Mediated Synergistic Photodynamic and Glutamine-Metabolic Therapy Enabled by a Biomimetic Targeting Nanosystem for Cholangiocarcinoma

Targeted delivery of glutamine metabolism inhibitors holds promise for cholangiocarcinoma therapy, yet effective delivery vehicles remain a challenge. This study reports the development of a biomimetic nanosystem, termed R-CM@MSN@BC, integrating mesoporous organosilicon nanoparticles with reactive oxygen species-responsive diselenide bonds for controlled release of the glutamine metabolism inhibitor bis-2-(5-phenylacetamido-1,3,4-thiadiazol-2-yl) ethyl sulfide (BPTES) and the photosensitizer Ce6. Erythrocyte membrane coating, engineered with Arg-Gly-Asp (RGD) peptides, not only enhanced biocompatibility but also improved tumor targeting and tissue penetration. Upon laser irradiation, R-CM@MSN@BC executed both photodynamic and glutamine-metabolic therapies, inducing necroptosis in tumor cells and triggering significant immunogenic cell death. Time-of-flight mass cytometry analysis revealed that R-CM@MSN@BC can remodel the immunosuppressive tumor microenvironment by polarizing M1-type macrophages, reducing infiltration of M2-type and CX3CR1+ macrophages, and decreasing T cell exhaustion, thereby increasing the effectiveness of anti-programmed cell death ligand 1 immunotherapy. This strategy proposed in this study presents a viable and promising approach for the treatment of cholangiocarcinoma.

Immunometabolism of CD8+ T cell differentiation in cancer

CD8+ cytotoxic T lymphocytes (CTLs) are central mediators of tumor immunity and immunotherapies. Upon tumor antigen recognition, CTLs differentiate from naive/memory-like toward terminally exhausted populations with more limited function against tumors. Such differentiation is regulated by both immune signals, including T cell receptors (TCRs), co-stimulation, and cytokines, and metabolism-associated processes. These immune signals shape the metabolic landscape via signaling, transcriptional and post-transcriptional mechanisms, while metabolic processes in turn exert spatiotemporal effects to modulate the strength and duration of immune signaling. Here, we review the bidirectional regulation between immune signals and metabolic processes, including nutrient uptake and intracellular metabolic pathways, in shaping CTL differentiation and exhaustion. We also discuss the mechanisms underlying how specific nutrient sources and metabolite-mediated signaling events orchestrate CTL biology. Understanding how metabolic programs and their interplay with immune signals instruct CTL differentiation and exhaustion is crucial to uncover tumor-immune interactions and design novel immunotherapies.

Tuning cellular metabolism for cancer virotherapy

Oncolytic viruses (OVs) represent an emerging immunotherapeutic strategy owing to their capacity for direct tumor lysis and induction of antitumor immunity. However, hurdles like transient persistence and moderate efficacy necessitate innovative approaches. Metabolic remodeling has recently gained prominence as a strategic intervention, wherein OVs or combination regimens could reprogram tumor and immune cell metabolism to enhance viral replication and oncolysis. In this review, we summarize recent advances in strategic reprogramming of tumor and immune cell metabolism to enhance OV-based immunotherapies. Specific tactics include engineering viruses to target glycolytic, glutaminolytic, and nucleotide synthesis pathways in cancer cells, boosting viral replication and tumor cell death. Additionally, rewiring T cell and NK cell metabolism of lipids, amino acids, and carbohydrates shows promise to enhance antitumor effects. Further insights are discussed to pave the way for the clinical implementation of metabolically enhanced oncolytic platforms, including balancing metabolic modulation to limit antiviral responses while promoting viral persistence and tumor clearance.

Immunonutrition, Metabolism, and Programmed Cell Death in Lung Cancer: Translating Bench to Bedside

Lung cancer presents significant therapeutic challenges, motivating the exploration of novel treatment strategies. Programmed cell death (PCD) mechanisms, encompassing apoptosis, autophagy, and programmed necrosis, are pivotal in lung cancer pathogenesis and the treatment response. Dysregulation of these pathways contributes to tumor progression and therapy resistance. Immunonutrition, employing specific nutrients to modulate immune function, and metabolic reprogramming, a hallmark of cancer cells, offer promising avenues for intervention. Nutritional interventions, such as omega-3 fatty acids, exert modulatory effects on PCD pathways in cancer cells, while targeting metabolic pathways implicated in apoptosis regulation represents a compelling therapeutic approach. Clinical evidence supports the role of immunonutritional interventions, including omega-3 fatty acids, in augmenting PCD and enhancing treatment outcomes in patients with lung cancer. Furthermore, synthetic analogs of natural compounds, such as resveratrol, demonstrate promising anticancer properties by modulating apoptotic signaling pathways. This review underscores the convergence of immunonutrition, metabolism, and PCD pathways in lung cancer biology, emphasizing the potential for therapeutic exploration in this complex disease. Further elucidation of the specific molecular mechanisms governing these interactions is imperative for translating these findings into clinical practice and improving lung cancer management.

13C metabolite tracing reveals glutamine and acetate as critical in vivo fuels for CD8 T cells

Infusion of 13C-labeled metabolites provides a gold standard for understanding the metabolic processes used by T cells during immune responses in vivo. Through infusion of 13C-labeled metabolites (glucose, glutamine, and acetate) in Listeria monocytogenes-infected mice, we demonstrate that CD8 T effector (Teff) cells use metabolites for specific pathways during specific phases of activation. Highly proliferative early Teff cells in vivo shunt glucose primarily toward nucleotide synthesis and leverage glutamine anaplerosis in the tricarboxylic acid (TCA) cycle to support adenosine triphosphate and de novo pyrimidine synthesis. In addition, early Teff cells rely on glutamic-oxaloacetic transaminase 1 (Got1)-which regulates de novo aspartate synthesis-for effector cell expansion in vivo. CD8 Teff cells change fuel preference over the course of infection, switching from glutamine- to acetate-dependent TCA cycle metabolism late in infection. This study provides insights into the dynamics of Teff metabolism, illuminating distinct pathways of fuel consumption associated with CD8 Teff cell function in vivo.

Metabolic rewiring and communication in cancer immunity

The immune system shapes tumor development and progression. Although immunotherapy has transformed cancer treatment, its overall efficacy remains limited, underscoring the need to uncover mechanisms to improve therapeutic effects. Metabolism-associated processes, including intracellular metabolic reprogramming and intercellular metabolic crosstalk, are emerging as instructive signals for anti-tumor immunity. Here, we first summarize the roles of intracellular metabolic pathways in controlling immune cell function in the tumor microenvironment. How intercellular metabolic communication regulates anti-tumor immunity, and the impact of metabolites or nutrients on signaling events, are also discussed. We then describe how targeting metabolic pathways in tumor cells or intratumoral immune cells or via nutrient-based interventions may boost cancer immunotherapies. Finally, we conclude with discussions on profiling and functional perturbation methods of metabolic activity in intratumoral immune cells, and perspectives on future directions. Uncovering the mechanisms for metabolic rewiring and communication in the tumor microenvironment may enable development of novel cancer immunotherapies.

IL-1α facilitates GSH synthesis to counteract oxidative stress in oral squamous cell carcinoma under glucose-deprivation

Understanding the intrinsic mechanisms underpinning cancer metabolism and therapeutic resistance is of central importance for effective nutrition-starvation therapies. Here, we report that Interleukin 1A (IL1A) mRNA and IL-1α protein facilitate glutathione (GSH) synthesis to counteract oxidative stress and resistance against nutrition-starvation therapy in oral squamous cell carcinoma (OSCC). The expression of IL1A mRNA was elevated in the case of OSCC associated with unfavorable clinical outcomes. Both IL1A mRNA and IL-1α protein expression were increased under glucose-deprivation in vitro and in vivo. The transcription of IL1A mRNA was regulated in an NRF2-dependent manner in OSCC cell lines under glucose-deprivation. Moreover, the IL-1α conferred resistance to oxidative stress via GSH synthesis in OSCC cell lines. The intratumoral administration of siRNAs against IL1A mRNA markedly reversed GSH production and sensitized OSCC cells to Anlotinib in HN6 xenograft models. Overall, the current study demonstrates novel evidence that the autocrine IL-1α favors endogenous anti-oxidative process and confers therapeutic resistance to nutrition-starvation in OSCCs.

Glutamine antagonist DRP-104 suppresses tumor growth and enhances response to checkpoint blockade in KEAP1 mutant lung cancer

Loss-of-function mutations in KEAP1 frequently occur in lung cancer and are associated with poor prognosis and resistance to standard of care treatment, highlighting the need for the development of targeted therapies. We previously showed that KEAP1 mutant tumors consume glutamine to support the metabolic rewiring associated with NRF2-dependent antioxidant production. Here, using preclinical patient-derived xenograft models and antigenic orthotopic lung cancer models, we show that the glutamine antagonist prodrug DRP-104 impairs the growth of KEAP1 mutant tumors. We find that DRP-104 suppresses KEAP1 mutant tumors by inhibiting glutamine-dependent nucleotide synthesis and promoting antitumor T cell responses. Using multimodal single-cell sequencing and ex vivo functional assays, we demonstrate that DRP-104 reverses T cell exhaustion, decreases Tregs, and enhances the function of CD4 and CD8 T cells, culminating in an improved response to anti-PD1 therapy. Our preclinical findings provide compelling evidence that DRP-104, currently in clinical trials, offers a promising therapeutic approach for treating patients with KEAP1 mutant lung cancer.

Boosting immune responses in lung tumor immune microenvironment: A comprehensive review of strategies and adjuvants

The immune system has a substantial impact on the growth and expansion of lung malignancies. Immune cells are encompassed by a stroma comprising an extracellular matrix (ECM) and different cells like stromal cells, which are known as the tumor immune microenvironment (TIME). TME is marked by the presence of immunosuppressive factors, which inhibit the function of immune cells and expand tumor growth. In recent years, numerous strategies and adjuvants have been developed to extend immune responses in the TIME, to improve the efficacy of immunotherapy. In this comprehensive review, we outline the present knowledge of immune evasion mechanisms in lung TIME, explain the biology of immune cells and diverse effectors on these components, and discuss various approaches for overcoming suppressive barriers. We highlight the potential of novel adjuvants, including toll-like receptor (TLR) agonists, cytokines, phytochemicals, nanocarriers, and oncolytic viruses, for enhancing immune responses in the TME. Ultimately, we provide a summary of ongoing clinical trials investigating these strategies and adjuvants in lung cancer patients. This review also provides a broad overview of the current state-of-the-art in boosting immune responses in the TIME and highlights the potential of these approaches for improving outcomes in lung cancer patients.

A glutamine tug-of-war between cancer and immune cells: recent advances in unraveling the ongoing battle

Glutamine metabolism plays a pivotal role in cancer progression, immune cell function, and the modulation of the tumor microenvironment. Dysregulated glutamine metabolism has been implicated in cancer development and immune responses, supported by mounting evidence. Cancer cells heavily rely on glutamine as a critical nutrient for survival and proliferation, while immune cells require glutamine for activation and proliferation during immune reactions. This metabolic competition creates a dynamic tug-of-war between cancer and immune cells. Targeting glutamine transporters and downstream enzymes involved in glutamine metabolism holds significant promise in enhancing anti-tumor immunity. A comprehensive understanding of the intricate molecular mechanisms underlying this interplay is crucial for developing innovative therapeutic approaches that improve anti-tumor immunity and patient outcomes. In this review, we provide a comprehensive overview of recent advances in unraveling the tug-of-war of glutamine metabolism between cancer and immune cells and explore potential applications of basic science discoveries in the clinical setting. Further investigations into the regulation of glutamine metabolism in cancer and immune cells are expected to yield valuable insights, paving the way for future therapeutic interventions.

Unlocking the potential of T-cell metabolism reprogramming: Advancing single-cell approaches for precision immunotherapy in tumour immunity

As single-cell RNA sequencing enables the detailed clustering of T-cell subpopulations and facilitates the analysis of T-cell metabolic states and metabolite dynamics, it has gained prominence as the preferred tool for understanding heterogeneous cellular metabolism. Furthermore, the synergistic or inhibitory effects of various metabolic pathways within T cells in the tumour microenvironment are coordinated, and increased activity of specific metabolic pathways generally corresponds to increased functional activity, leading to diverse T-cell behaviours related to the effects of tumour immune cells, which shows the potential of tumour-specific T cells to induce persistent immune responses. A holistic understanding of how metabolic heterogeneity governs the immune function of specific T-cell subsets is key to obtaining field-level insights into immunometabolism. Therefore, exploring the mechanisms underlying the interplay between T-cell metabolism and immune functions will pave the way for precise immunotherapy approaches in the future, which will empower us to explore new methods for combating tumours with enhanced efficacy.

KEAP1 promotes anti-tumor immunity by inhibiting PD-L1 expression in NSCLC

Immunotherapy has become a prominent first-line cancer treatment strategy. In non-small cell lung cancer (NSCLC), the expression of PD-L1 induces an immuno-suppressive effect to protect cancer cells from immune elimination, which designates PD-L1 as an important target for immunotherapy. However, little is known about the regulation mechanism and the function of PD-L1 in lung cancer. In this study, we have discovered that KEAP1 serves as an E3 ligase to promote PD-L1 ubiquitination and degradation. We found that overexpression of KEAP1 suppressed tumor growth and promoted cytotoxic T-cell activation in vivo. These results indicate the important role of KEAP1 in anti-cancer immunity. Moreover, the combination of elevated KEAP1 expression with anti-PD-L1 immunotherapy resulted in a synergistic effect on both tumor growth and cytotoxic T-cell activation. Additionally, we found that the expressions of KEAP1 and PD-L1 were associated with NSCLC prognosis. In summary, our findings shed light on the mechanism of PD-L1 degradation and how NSCLC immune escape through KEAP1-PD-L1 signaling. Our results also suggest that KEAP1 agonist might be a potential clinical drug to boost anti-tumor immunity and improve immunotherapies in NSCLC.

Unveiling the role of KRAS in tumor immune microenvironment

Kirsten rats sarcoma viral oncogene (KRAS), the first discovered human oncogene, has long been recognized as "undruggable". KRAS mutations frequently occur in multiple human cancers including non-small cell lung cancer(NSCLC), colorectal cancer(CRC) and pancreatic ductal adenocarcinoma(PDAC), functioning as a "molecule switch" determining the activation of various oncogenic signaling pathways. Except for its intrinsic pro-tumorigenic role, KRAS alteration also exhibits an unique immune signature characterized by elevated PD-L1 level and high tumor mutational burden(TMB). KRAS mutation shape an immune suppressive microenvironment by impeding effective T cells infiltration and recruiting suppressive immune cells including myeloid-derived suppressor cells(MDSCs), regulatory T cells(Tregs), cancer associated fibroblasts(CAFs). In immune checkpoint inhibitor(ICI) era, NSCLC patients with mutated KRAS tend to be more responsive to ICI than patients with intact KRAS. The hallmark for KRAS mutation is the existence of multiple kinds of co-mutations. Different types of co-alterations have distinct tumor microenvironment(TME) signatures and responses to ICI. TP53 co-mutation possess a "hot" TME and achieve higher response to immunotherapy while other loss of function mutation correlated with a "colder" TME and a poor outcome to ICI-based therapy. The groundbreaking discovery of KRAS G12C inhibitors significantly improved outcomes for this KRAS subtype even though efficacy was limited to NSCLC patients. KRAS G12C inhibitors also restore the suppressive TME, creating an opportunity for combinations with ICI. However, an inevitable challenge to KRAS inhibitors is drug resistance. Promising combination strategies such as combination with SHP2 is an approach deserve further exploration because of their immune modulatory effect.

Nanotechnology Reprogramming Metabolism for Enhanced Tumor Immunotherapy

Mutation burden, hypoxia, and immunoediting contribute to altered metabolic profiles in tumor cells, resulting in a tumor microenvironment (TME) characterized by accumulation of toxic metabolites and depletion of various nutrients, which significantly hinder the antitumor immunity via multiple mechanisms, hindering the efficacy of tumor immunotherapies. In-depth investigation of the mechanisms underlying these phenomena are vital for developing effective antitumor drugs and therapies, while the therapeutic effects of metabolism-targeting drugs are restricted by off-target toxicity toward effector immune cells and high dosage-mediated side effects. Nanotechnologies, which exhibit versatility and plasticity in targeted delivery and metabolism modulation, have been widely applied to boost tumor immunometabolic therapies via multiple strategies, including targeting of metabolic pathways. In this review, recent advances in understanding the roles of tumor cell metabolism in both immunoevasion and immunosuppression are reviewed, and nanotechnology-based metabolic reprogramming strategies for enhanced tumor immunotherapies are discussed.

Next batter up! Targeting cancers with KRAS-G12D mutations

KRAS is the most frequently mutated oncogene in cancer. Activating mutations in codon 12, especially G12D, have the highest prevalence across a range of carcinomas and adenocarcinomas. With inhibitors to KRAS-G12D now entering clinical trials, understanding the biology of KRAS-G12D cancers, and identifying biomarkers that predict therapeutic response is crucial. In this Review, we discuss the genomics and biology of KRAS-G12D adenocarcinomas, including histological features, transcriptional landscape, the immune microenvironment, and how these factors influence response to therapy. Moreover, we explore potential therapeutic strategies using novel G12D inhibitors, leveraging knowledge gained from clinical trials using G12C inhibitors.

Immunometabolism of dendritic cells in health and disease

Dendritic cells (DCs) are crucial mediators that bridge the innate and adaptive immune responses. Cellular rewiring of metabolism is an emerging regulator of the activation, migration, and functional specialization of DC subsets in specific microenvironments and immunological conditions. DCs undergo metabolic adaptation to exert immunogenic or tolerogenic effects in different contexts. Also, beyond their intracellular metabolic and signaling roles, metabolites and nutrients mediate the intercellular crosstalk between DCs and other cell types, and such crosstalk orchestrates DC function and immune responses. Here, we provide a comprehensive review of the metabolic regulation of DC biology in various contexts and summarize the current understanding of such regulation in directing immune homeostasis and inflammation, specifically with respect to infections, autoimmunity, tolerance, cancer, metabolic diseases, and crosstalk with gut microbes. Understanding context-specific metabolic alterations in DCs may identify mechanisms for physiological and pathological functions of DCs and yield potential opportunities for therapeutic targeting of DC metabolism in many diseases.

Regulation and signaling pathways in cancer stem cells: implications for targeted therapy for cancer

Cancer stem cells (CSCs), initially identified in leukemia in 1994, constitute a distinct subset of tumor cells characterized by surface markers such as CD133, CD44, and ALDH. Their behavior is regulated through a complex interplay of networks, including transcriptional, post-transcriptional, epigenetic, tumor microenvironment (TME), and epithelial-mesenchymal transition (EMT) factors. Numerous signaling pathways were found to be involved in the regulatory network of CSCs. The maintenance of CSC characteristics plays a pivotal role in driving CSC-associated tumor metastasis and conferring resistance to therapy. Consequently, CSCs have emerged as promising targets in cancer treatment. To date, researchers have developed several anticancer agents tailored to specifically target CSCs, with some of these treatment strategies currently undergoing preclinical or clinical trials. In this review, we outline the origin and biological characteristics of CSCs, explore the regulatory networks governing CSCs, discuss the signaling pathways implicated in these networks, and investigate the influential factors contributing to therapy resistance in CSCs. Finally, we offer insights into preclinical and clinical agents designed to eliminate CSCs.

Enhancing personalized immune checkpoint therapy by immune archetyping and pharmacological targeting

Immune checkpoint inhibitors (ICIs) are an expanding class of immunotherapeutic agents with the potential to cure cancer. Despite the outstanding clinical response in patient subsets, most individuals become refractory or develop resistance. Patient stratification and personalized immunotherapies are limited by the absence of predictive response markers. Recent findings show that dominant patterns of immune cell composition, T-cell status and heterogeneity, and spatiotemporal distribution of immune cells within the tumor microenvironment (TME) are becoming essential determinants of prognosis and therapeutic response. In this context, ICIs also function as investigational tools and proof of concept, allowing the validation of the identified mechanisms. After reviewing the current state of ICIs, this article will explore new comprehensive predictive markers for ICIs based on recent discoveries. We will discuss the recent establishment of a classification of TMEs into immune archetypes as a tool for personalized immune profiling, allowing patient stratification before ICI treatment. We will discuss the developing comprehension of T-cell diversity and its role in shaping the immune profile of patients. We describe the potential of strategies that score the mutual spatiotemporal modulation between T-cells and other cellular components of the TME. Additionally, we will provide an overview of a range of synthetic and naturally occurring or derived small molecules. We will compare compounds that were recently identified by in silico prediction to wet lab-validated drug candidates with the potential to function as ICIs and/or modulators of the cellular components of the TME.