Inhibition of TCA cycle improves the anti-PD-1 immunotherapy efficacy in melanoma cells via ATF3-mediated PD-L1 expression and glycolysis

PTP Inhibition Improves the Macrophage Antitumor Immune Response and the Efficacy of Chemo- and Radiotherapy

Traditional anticancer therapies induce tumor cell death and subsequent release of damage-associated molecular patterns (DAMPs) that activate the innate inflammatory response. Paradoxically, after treatment, macrophages often adopt a pro-wound healing, rather than proinflammatory, phenotype and contribute to cancer progression. We found that in areas proximal to DAMP release, tumor cells upregulate the expression of Pros1. Tumor-secreted Pros1 binds to the macrophage Mer receptor, consequently limiting responsiveness to DAMPs by preventing Toll-like receptor signal transduction. Pharmacological inhibition of PTP1b signaling downstream of Mer rescued the proinflammatory response, even in the presence of Pros1. Combining protein tyrosine phosphatase (PTP) inhibition with traditional therapeutics, such as chemo- or radiotherapy, rescued the innate immune response to DAMPs, increased immune infiltration, and resulted in a 40% to 90% reduction in tumor growth in multiple treatment-refractory preclinical models. Our findings suggest using PTP1b inhibitors may be a tumor agnostic means of improving the efficacy of some of the most widely used anticancer therapeutic agents.

The landscape of ATF3 in tumors: Metabolism, expression regulation, therapy approach, and open concerns

Cellular stress response is a pivotal process in tumor development and therapy. Activating transcription factor 3 (ATF3), a representative stress-responsive protein, plays pleiotropic roles in various biological processes. Over the past decade, studies have described not only the general role of ATF3 in tumor metabolism but also the complexity of ATF3 expression regulation and its associated modifications, including phosphorylation, ubiquitination, SUMOylation, and NEDDylation. Interestingly, beyond being a transcription factor, ATF3 can act as a modifier to control the ubiquitination of target molecules, such as p53, to exert its function in tumors. These advances in uncovering ATF3 biological function have yielded new insights into the cellular stress response during tumor development and will be instrumental in developing novel interventions. In this review, we update the role of ATF3 as a nexus in amino acid metabolism, lipid metabolism, glycometabolism, and other metabolic pathways in tumors; delineate the underlying mechanisms involving DNA level regulation, epigenetic regulation, and post-translational modifications of ATF3; and summarize the progression of tumor mono/combination therapies related to ATF3. In particular, we discuss the challenges that need to be addressed to provide a new conceptual framework for further understanding the potential therapeutic value of ATF3 in ongoing clinical trials.

Identification of immune characteristic biomarkers and therapeutic targets in cuproptosis for rheumatoid arthritis by integrated bioinformatics analysis and single-cell RNA sequencing analysis

Introduction

Rheumatoid arthritis (RA) is a chronic autoimmune disorder intricately liked with inflammation. Cuproptosis, an emerging type of cell death, has been implicated in the initiation and development of RA. However, the exact alterations in the expression and biological function of cuproptosis-related genes (CRGs) in RA remain poorly understood. Therefore, our study aims to elucidate the potential association between CRGs and RA, with the goal of identifying novel biomarkers for the treatment and prognosis of RA.

Methods

In this study, we identified ten differentially expressed cuproptosis-related genes (DE-CRGs) between patients with RA and controls. Through comprehensive functional enrichment and protein-protein interaction (PPI) network analysis, we explored the functional roles of the DE-CRGs. Additionally, we investigated the correlation between DE-CRGs and immune infiltration, immune factors, diagnostic efficacy, and potential therapeutic drugs.

Results

Leveraging single-cell RNA sequencing data, we conducted a detailed analysis to elucidate alterations in various cell clusters associated with RA. Our study unveiled a significant association between DE-CRGs and diverse biological functions, as well as potential drug candidates.

Discussion

These findings provide crucial insights into the involvement of DE-CRGs in the pathogenesis of RA and shed light on potential therapeutic strategies.

Fasting enhances the efficacy of Sorafenib in breast cancer via mitophagy mediated ROS-driven p53 pathway

The multi-kinase inhibitor sorafenib has shown potential to inhibit tumor cell growth and intra-tumoral angiogenesis by targeting several kinases, including VEGFR2 and RAF. Abnormal activation of the Ras/Raf/MAPK/ERK kinase cascade and the VEGF pathway is a common feature in breast cancer. However, the efficacy of sorafenib in breast cancer treatment remains limited. Recently, fasting has emerged as a promising non-pharmacological approach to modulate cancer metabolism and enhance the effectiveness of cancer therapies. In this study, we found that fasting significantly enhances the anti-cancer effects of sorafenib monotherapy and its combination with immunotherapy in breast cancer models without causing obvious side effects. This combined treatment effectively inhibits tumor cell proliferation and intra-tumoral angiogenesis. The fasting-induced reduction in peripheral blood glucose levels strongly correlated with enhanced sensitivity to sorafenib. Mechanistically, the combined treatment induced mitophagy, characterized by mitochondrial dysfunction and activation of the PINK1-Parkin pathway. Consequently, increased mitochondrial ROS levels promoted p53 expression, amplifying cell cycle arrest and apoptosis in breast cancer cells. Furthermore, fasting reduced lactate levels within the tumor, and the consequent glucose limitation synergized with sorafenib to activate AMPK, which in turn elevated PD-L1 expression in tumor cells, potentially enhancing their sensitivity to immunotherapy. In summary, our findings demonstrate that fasting and sorafenib, as a rational combination therapy, induce mitophagy, thereby enhancing sorafenib's efficacy in treating breast cancer through the ROS-driven p53 pathway. This study underscores the potential of fasting in breast cancer therapy and provides a foundation for optimizing the clinical application of sorafenib.

Effects of combined exposure to 17α-methyltestosterone and polystyrene microplastics on lipid metabolism and the nervous system in Danio rerio

Polystyrene (PS) microplastics are pervasive environmental pollutants that are harmful to aquatic organisms upon degradation. The synthetic androgen 17α-methyltestosterone (MT) is an environmental endocrine-disrupting chemical. This study aimed to systematically evaluate the combined histological and molecular effects of MT and PS exposure on the liver and brain tissues of Danio rerio with focus on lipid metabolism and neural function disruption. Female D. rerio were exposed to 50 ng/L MT and 0.5 mg/L PS (5 μm in diameter) for 21 d. Histological observations, real-time quantitative PCR (qPCR), and RNA-sequencing (RNA-seq) analysis were employed to assess the effects of PS and MT. These results indicated that MT and PS co-exposure caused fatty degeneration of liver cells and a significant upregulation of lipid synthesis-related genes (ACSS1, CEL, FASN, and GK5). In brain tissue, the observed effects included reduced marginal layer neuron counts, cytoplasmic loosening of central layer neurons, disordered gray matter layer cells, and vascular congestion. RNA-seq analysis further revealed significant enrichment of differentially expressed genes in the "glycine, serine, and threonine metabolism" and "neuroactive ligand-receptor interaction" signaling pathways. Thus, MT and PS co-exposure induced lipid metabolism disorders in D. rerio and influence neural signaling by altering the "neuroactive ligand-receptor interaction" pathway. These findings highlight the complex risks posed by environmental pollutants to aquatic life and provide critical insights for environmental protection and aquatic health research.

Eravacycline improves the efficacy of anti-PD1 immunotherapy via AP1/CCL5 mediated M1 macrophage polarization in melanoma

Screening approved library is a promising and safe strategy to overcome the limitation of low response rate and drug resistance in immunotherapy. Accumulating evidence showed that the application of antibiotics has been considered to reduce the effectiveness of anti-PD1 immunotherapy in tumor treatment, however, in this study, an antibiotic drug (Eravacycline, ERV) was identified to improve the efficacy of anti-PD1 immunotherapy in melanoma through screening approved library. Administration of ERV significantly attenuated melanoma cells growth as well as directly or indirectly benefited M1 macrophage polarization. Meanwhile, ERV treatment significantly induced cellular autophagy via damage of mitochondria, leading to up-regulation of ROS production, subsequently, raised CCL5 secretion through elevation AP1 binding to CCL5 promoter via p38 or JNK1/2 activation. Knockdown of Ccl5 expression attenuated ERV triggered M1 macrophage polarization in melanoma cells. Clinical analysis revealed a positive association between high expression of CCL5 and improved prognosis as well as a favorable anti-PD1 therapy in melanoma patients. As expected, application of ERV improved the efficacy of anti-PD1. Overall, our results approved that ERV enhances the efficacy of anti-PD1 immunotherapy in melanoma by promoting the polarization of M1 macrophages, which provided novel therapeutic strategy for improving the effectiveness of melanoma anti-PD1 immunotherapy.

Metabolism of Tryptophan, Glutamine, and Asparagine in Cancer Immunotherapy-Synergism or Mechanism of Resistance?

Amino acids are crucial components of proteins, key molecules in cellular physiology and homeostasis. However, they are also involved in a variety of other mechanisms, such as energy homeostasis, nitrogen exchange, further synthesis of bioactive compounds, production of nucleotides, or activation of signaling pathways. Moreover, amino acids and their metabolites have immunoregulatory properties, significantly affecting the behavior of immune cells. Immunotherapy is one of the oncological treatment methods that improves cytotoxic properties of one's own immune system. Thus, enzymes catalyzing amino acid metabolism, together with metabolites themselves, can affect immune antitumor properties and responses to immunotherapy. In this review, we will discuss the involvement of tryptophan, glutamine, and asparagine metabolism in the behavior of immune cells targeted by immunotherapy and summarize results of the most recent investigations on the impact of amino acid metabolites on immunotherapy.

Single-atom-doped piezocatalyst induces copper-free cuproptosis in tumor therapy

Cuproptosis, a distinct cell death pathway, has been integrated into nanomedicine for disease theranostics. However, current nanosystems inducing cuproptosis rely on exogenous toxic copper ions, limiting the scope of biomaterials. Developing nanoplatforms that induce cuproptosis without exogenous copper holds substantial promise. Here, we engineered a two-dimensional iron (Fe) single-atom-doped molybdenum disulfide (MoS2) piezocatalyst (Fe-MoS2) for tumor therapy. Incorporating single Fe atoms enhances MoS2 piezoelectric polarization via charge redistribution and modulates Fe and Mo oxidation states, enabling multifaceted enzymatic activities, including peroxidase-, glutathione oxidase-, oxidase-, and catalase-like activities. Upon ultrasound stimulation, the Fe-MoS2 nanocatalyst generates reactive oxygen species and depletes glutathione via synergistic piezocatalytic and enzyocatalytic effects, disrupting copper ion homeostasis and inducing cuproptosis, concurrently triggering ferroptosis and ferritinophagy, which collectively enhances tumor suppression. This study represents the first paradigm to introduce a copper-free piezocatalyst for initiating cuproptosis, substantially advancing the applications of cuproptosis in tumor therapy.

Clofarabine induces tumor cell apoptosis, GSDME-related pyroptosis, and CD8+ T-cell antitumor activity via the non-canonical P53/STING pathway

BACKGROUND

Clofarabine (Clo) is a Food and Drug Administration (FDA)-approved drug for the treatment of acute lymphoblastic leukemia; however, its effects on solid tumors remain largely unknown.

METHODS

In vitro and in vivo experiments have demonstrated the cytotoxic effects of Clo on melanoma and lung cancer. The molecular mechanisms of Clo-induced tumor cell death were analyzed using western blotting, ELISA, reverse transcription-PCR, immunofluorescence, co-immunoprecipitation (CO-IP), short hairpin RNA, co-culture, chromatin immunoprecipitation, and flow cytometry. Clinical data sets were used to analyze the correlation between stimulator of interferon genes (STING)-NFκB signaling and immune infiltration.

RESULTS

In this study, Clo significantly reduced the growth of melanoma and lung cancer cells. Furthermore, Clo treatment induced GSDME-mediated pyroptosis. Most importantly, Clo administration dramatically increased the cytotoxic activity of CD8+ T cells in vitro and in vivo. Mechanistically, the administration of Clo induced the interaction of P53 with STING, which activated the non-canonical STING-NFκB pathway; consequently, NF-κB directly bound to the promoter regions of its target genes, including CCL5, CXCL10, HLAs and BAX. This resulted in apoptosis, pyroptosis, and immunogenic cell death in tumor cells by Clo. Furthermore, Clo-induced GSDME-mediated pyroptosis partly assists in activating T cell immunity via CCL5 and CXCL10. The non-canonical STING-NF-κB pathway is the crucial signaling pathway that initiates and links apoptosis, pyroptosis, and immunogenic cell death.

CONCLUSIONS

Our study is the first to show that Clo, an FDA-approved drug, induces tumor cell apoptosis, GSDME-related pyroptosis, and CD8+ T-cell antitumor activity via the non-canonical P53-STING-NF-κB signaling pathway, providing a novel strategy for the clinical therapy of melanoma and lung cancer.

ATF3 regulates CDC42 transcription and influences cytoskeleton remodeling, thus inhibiting the proliferation, migration and invasion of malignant skin melanoma cells

Cutaneous malignant melanoma (CMM) is one of the most aggressive and lethal types of skin cancer. Cytoskeletal remodeling is a key factor in the progression of CMM. Previous research has shown that activating transcription factor 3 (ATF3) inhibits metastasis in bladder cancer by regulating actin cytoskeleton remodeling through gelsolin. However, whether ATF3 plays a similar role in cytoskeletal remodeling in CMM cells remains unknown. Various gene and protein expression analyses were performed using techniques such as reverse transcription quantitative PCR, western blot, immunofluorescent staining, and immunohistochemical staining. CMM viability, migration, and invasion were examined through cell counting kit-8 and transwell assays. The interactions between cell division cycle 42 (CDC42) and ATF3 were investigated using chromatin immunoprecipitation and dual-luciferase reporter assays. CDC42 was upregulated in CMM tissues and cells. Cytoskeletal remodeling of CMM cells, as well as CMM cell proliferation, migration, and invasion, were inhibited by CDC42 or ATF3. ATF3 targeted the CDC42 promoter region to regulate its transcriptional activity. ATF3 suppresses cytoskeletal remodeling in CMM cells, thereby inhibiting CMM progression and metastasis through CDC42. This research may provide a foundation for using ATF3 as a therapeutic target for CMM.

The function and mechanism of clinical trial agent CPI-613 in multiple myeloma

Multiple myeloma (MM) is an incurable malignant hematological neoplasm characterized by clonal proliferation of plasma cells accumulating in the bone marrow. Currently, the treatment of MM is usually based on a multi-drug combination strategy, and the remission rates of MM patients have been greatly improved. However, MM is still not immune to drug resistance and recurrence and is an incurable tumor. In this study, a comprehensive screen of the TCA cycle identified oxoglutarate dehydrogenase (OGDH) and pyruvate dehydrogenase E1 subunit alpha 1 (PDHA1) as the most clinically relevant genes in MM, highlighting their potential as therapeutic targets. CPI-613, a novel non-redox-active lipoic acid analog that causes mitochondrial metabolism dysfunction by targeting OGDH and PDHA1, is currently in clinical trials in a variety of malignancies. In our study, CPI-613 was found to inhibit the proliferation of MM cells, and its combination with bortezomib (BTZ) produced a significant inhibitory effect at lower doses. In addition, CPI-613 can disrupt various mitochondrial functions, such as disrupting mitochondrial morphology, reducing oxidative phosphorylation, decreasing 5'- adenylate triphosphate production, and increasing reactive oxygen species, which ultimately leads to cell death mediated by the intrinsic apoptotic pathway in vitro. Furthermore, we found CPI-613 significantly inhibited tumor growth and induced intrinsic apoptosis in the MM mouse xenograft model. This study reveals the mechanism and effect of CPI-613 in MM, which suggests that CPI-613 may be a new drug option for the clinical treatment of MM, but further clinical trials are needed for evaluation.

Global trends and emerging insights in BRAF and MEK inhibitor resistance in melanoma: a bibliometric analysis

Objective

This study aims to perform a comprehensive bibliometric analysis of global research on BRAF and MEK inhibitor resistance in melanoma, identifying key research trends, influential contributors, and emerging themes from 2003 to 2024.

Methods

A systematic search was conducted in the Web of Science Core Collection (WoSCC) database to retrieve publications related to BRAF and MEK inhibitor resistance from 1 January 2003, to 1 September 2024. Bibliometric analyses, including publication trends, citation networks, and keyword co-occurrence patterns, were performed using VOSviewer and CiteSpace. Collaborative networks, co-cited references, and keyword burst analyses were mapped to uncover shifts in research focus and global cooperation.

Results

A total of 3,503 documents, including 2,781 research articles and 722 review papers, were analyzed, highlighting significant growth in this field. The United States, China, and Italy led in publication volume and citation impact, with Harvard University and the University of California System among the top contributing institutions. Research output showed three phases of growth, peaking in 2020. Keyword and co-citation analyses revealed a transition from early focus on BRAF mutations and MAPK pathway activation to recent emphasis on immunotherapy, combination therapies, and non-apoptotic cell death mechanisms like ferroptosis and pyroptosis. These trends reflect the evolving priorities and innovative approaches shaping the field of resistance to BRAF and MEK inhibitors in melanoma.

Conclusion

Research on BRAF and MEK inhibitor resistance has evolved significantly. This analysis provides a strategic framework for future investigations, guiding the development of innovative, multi-modal approaches to improve treatment outcomes for melanoma patients.

A review of the pathogenesis of mitochondria in breast cancer and progress of targeting mitochondria for breast cancer treatment

With breast cancer being the most common tumor among women in the world today, it is also the leading cause of cancer-related deaths. Standard treatments include chemotherapy, surgery, endocrine therapy, and targeted therapy. However, the heterogeneity, drug resistance, and poor prognosis of breast cancer highlight an urgent need for further exploration of its underlying mechanisms. Mitochondria, highly dynamic intracellular organelles, play a pivotal role in maintaining cellular energy metabolism. Altered mitochondrial function plays a critical role in various diseases, and recent studies have elucidated its pathophysiological mechanisms in breast carcinogenesis. This review explores the role of mitochondrial dysfunction in breast cancer pathogenesis and assesses potential mitochondria-targeted therapies.

PLUNC downregulates the expression of PD-L1 by inhibiting the interaction of DDX17/β-catenin in nasopharyngeal carcinoma

BACKGROUND

Nasopharyngeal carcinoma (NPC) is characterized by high programmed death-ligand 1 (PD-L1) expression and abundant infiltration of non-malignant lymphocytes, which renders patients potentially suitable candidates for immune checkpoint blockade therapies. Palate, lung, and nasal epithelium clone (PLUNC) inhibit the growth of NPC cells and enhance cellular apoptosis and differentiation. Currently, the relationship between PLUNC (as a tumor-suppressor) and PD-L1 in NPC is unclear.

METHODS

We collected clinical samples of NPC to verify the relationship between PLUNC and PD-L1. PLUNC plasmid was transfected into NPC cells, and the variation of PD-L1 was verified by western blot and immunofluorescence. In NPC cells, we verified the relationship of PD-L1, activating transcription factor 3 (ATF3), and β-catenin by western blot and immunofluorescence. Later, we further verified that PLUNC regulates PD-L1 through β-catenin. Finally, the effect of PLUNC on β-catenin was verified by co-immunoprecipitation (Co-IP).

RESULTS

We found that PLUNC expression was lower in NPC tissues than in paracancer tissues. PD-L1 expression was opposite to that of PLUNC. Western blot and immunofluorescence showed that β-catenin could upregulate ATF3 and PD-L1, while PLUNC could downregulate ATF3/PD-L1 by inhibiting the expression of β-catenin. PLUNC inhibits the entry of β-catenin into the nucleus. Co-IP experiments demonstrated that PLUNC inhibited the interaction of DEAD-box helicase 17 (DDX17) and β-catenin.

CONCLUSIONS

PLUNC downregulates the expression of PD-L1 by inhibiting the interaction of DDX17/β-catenin in NPC.

The role of glycolysis in tumorigenesis: From biological aspects to therapeutic opportunities

Glycolytic metabolism generates energy and intermediates for biomass production. Tumor-associated glycolysis is upregulated compared to normal tissues in response to tumor cell-autonomous or non-autonomous stimuli. The consequences of this upregulation are twofold. First, the metabolic effects of glycolysis become predominant over those mediated by oxidative metabolism. Second, overexpressed components of the glycolytic pathway (i.e. enzymes or metabolites) acquire new functions unrelated to their metabolic effects and which are referred to as "moonlighting" functions. These functions include induction of mutations and other tumor-initiating events, effects on cancer stem cells, induction of increased expression and/or activity of oncoproteins, epigenetic and transcriptional modifications, bypassing of senescence and induction of proliferation, promotion of DNA damage repair and prevention of DNA damage, antiapoptotic effects, inhibition of drug influx or increase of drug efflux. Upregulated metabolic functions and acquisition of new, non-metabolic functions lead to biological effects that support tumorigenesis: promotion of tumor initiation, stimulation of tumor cell proliferation and primary tumor growth, induction of epithelial-mesenchymal transition, autophagy and metastasis, immunosuppressive effects, induction of drug resistance and effects on tumor accessory cells. These effects have negative consequences on the prognosis of tumor patients. On these grounds, it does not come to surprise that tumor-associated glycolysis has become a target of interest in antitumor drug discovery. So far, however, clinical results with glycolysis inhibitors have fallen short of expectations. In this review we propose approaches that may allow to bypass some of the difficulties that have been encountered so far with the therapeutic use of glycolysis inhibitors.

Multi-omics Insights into PDHA1 as a Predictive Biomarker for Prognosis, Immunotherapy Efficacy, and Drug Sensitivity in Hepatocellular Carcinoma

PDHA1 was associated with metabolic reprogramming in tumor progression. However, the clinical value of PDHA1, especially for prediction of drug sensitivity in hepatocellular carcinoma (HCC), has not been fully investigated. In this study, we found that PDHA1 expression was higher in HCC tissues compared to normal tissues and was correlated with poor prognosis in HCC patients. PDHA1 expression was mainly positively associated with immune cell infiltration using the TIMER, XCell, MCPCOUNTER, CIBERSORT, EPIC, and QUANTISEQ algorithms, which was validated by single-cell RNA-sequencing analysis. We also discovered that PDHA1 expression was correlated with six immune checkpoint-related genes. Univariate and multivariate Cox regression analyses revealed that PDHA1 expression was an independent prognostic indicator for HCC patients, and the nomogram incorporating PDHA1 expression exhibited excellent predictive capacity. Furthermore, PDHA1 expression was positively linked to the sensitivity of 5-fluorouracil, gemcitabine, paclitaxel, and sorafenib, and the molecular docking analysis demonstrated their excellent binding affinity.

Maternal Undernutrition Affects Fetal Thymus DNA Methylation, Gene Expression, and, Thereby, Metabolism and Immunopoiesis in Wagyu (Japanese Black) Cattle

We aimed to determine the effects of maternal nutrient restriction (MNR) on the DNA methylation and gene expression patterns associated with metabolism and immunopoiesis in the thymuses of fetal Wagyu cattle. Pregnant cows were allocated to two groups: a low-nutrition (LN; 60% nutritional requirement; n = 5) and a high-nutrition (HN; 120% nutritional requirement, n = 6) group, until 8.5 months of gestation. Whole-genome bisulfite sequencing (WGBS) and RNA sequencing were used to analyze DNA methylation and gene expression, while capillary electrophoresis-Fourier transform mass spectrometry assessed the metabolome. WGBS identified 4566 hypomethylated and 4303 hypermethylated genes in the LN group, with the intergenic regions most frequently being methylated. Pathway analysis linked hypoDMGs to Ras signaling, while hyperDMGs were associated with Hippo signaling. RNA sequencing found 94 differentially expressed genes (66 upregulated, 28 downregulated) in the LN group. The upregulated genes were tied to metabolic pathways and oxidative phosphorylation; the downregulated genes were linked to natural killer cell cytotoxicity. Key overlapping genes (GRIA1, CACNA1D, SCL25A4) were involved in cAMP signaling. The metabolomic analysis indicated an altered amino acid metabolism in the MNR fetuses. These findings suggest that MNR affects DNA methylation, gene expression, and the amino acid metabolism, impacting immune system regulation during fetal thymus development in Wagyu cattle.

Advances in immunotherapy for mucosal melanoma: harnessing immune checkpoint inhibitors for improved treatment outcomes

Mucosal melanoma (MM) poses a significant clinical challenge due to its aggressive nature and limited treatment options. In recent years, immunotherapy has emerged as a promising strategy for MM, with a particular focus on immune checkpoint inhibitors such as PD-1 and CTLA-4 inhibitors. These inhibitors have demonstrated substantial efficacy by harnessing the body's immune response against tumors. Moreover, adoptive cell transfer (ACT), anti-angiogenic therapy, and combination therapies have garnered attention for their potential in MM treatment. ACT involves modifying T cells to target melanoma cells, showing promising antitumor activity. Anti-angiogenic therapy aims to impede tumor growth by inhibiting angiogenesis, while combination therapies, including immune checkpoint inhibitors and targeted therapies, offer a multifaceted approach to overcome treatment resistance. This comprehensive review explores the advancements in immunotherapy for MM, highlighting the role of diverse therapeutic modalities in enhancing treatment outcomes and addressing the challenges posed by this aggressive malignancy.

DEPDC1 as a metabolic target regulates glycolysis in renal cell carcinoma through AKT/mTOR/HIF1α pathway

Renal cell carcinoma (RCC) is considered a "metabolic disease" characterized by elevated glycolysis in patients with advanced RCC. Tyrosine kinase inhibitor (TKI) therapy is currently an important treatment option for advanced RCC, but drug resistance may develop in some patients. Combining TKI with targeted metabolic therapy may provide a more effective approach for patients with advanced RCC. An analysis of 14 RCC patients (including three needle biopsy samples with TKI resistance) revealed by sing-cell RNA sequencing (scRNA-seq) that glycolysis played a crucial role in poor prognosis and drug resistance in RCC. TCGA-KIRC and glycolysis gene set analysis identified DEPDC1 as a target associated with malignant progression and drug resistance in KIRC. Subsequent experiments demonstrated that DEPDC1 promoted malignant progression and glycolysis of RCC, and knockdown DEPDC1 could reverse TKI resistance in RCC cell lines. Bulk RNA sequencing (RNA-seq) and non-targeted metabolomics sequencing suggested that DEPDC1 may regulate RCC glycolysis via AKT/mTOR/HIF1α pathway, a finding supported by protein-level analysis. Clinical tissue samples from 98 RCC patients demonstrated that DEPDC1 was associated with poor prognosis and predicted RCC metastasis. In conclusion, this multi-omics analysis suggests that DEPDC1 could serve as a novel target for TKI combined with targeted metabolic therapy in advanced RCC patients with TKI resistance.

Targeting metabolic pathways to counter cancer immunotherapy resistance

Immunotherapies have revolutionized the treatment of certain cancers, but challenges remain in overcoming immunotherapy resistance. Research shows that metabolic modulation of the tumor microenvironment can enhance antitumor immunity. Here, we discuss recent preclinical and clinical evidence for the efficacy of combining metabolic modifiers with immunotherapies. While this combination holds great promise, a few key areas must be addressed, which include identifying the effects of metabolic modifiers on immune cell metabolism, the putative biomarkers of therapeutic efficacy, the efficacy of modifiers on tumors harboring metabolic heterogeneity, and the potential development of resistance due to tumor reliance on alternative metabolic pathways. We propose solutions to these problems and posit that assessing these parameters is crucial for considering the potential of metabolic modifiers in sensitizing tumors to immunotherapies.

Decoding mitochondria's role in immunity and cancer therapy

The functions of mitochondria, including energy production and biomolecule synthesis, have been known for a long time. Given the rising incidence of cancer, the role of mitochondria in cancer has become increasingly popular. Activated by components released by mitochondria, various pathways interact with each other to induce immune responses to protect organisms from attack. However, mitochondria play dual roles in the progression of cancer. Abnormalities in proteins, which are the elementary structures of mitochondria, are closely linked with oncogenesis. Both the aberrant accumulation of intermediates and mutations in enzymes result in the generation and progression of cancer. Therefore, targeting mitochondria to treat cancer may be a new strategy. Several drugs aimed at inhibiting mutated enzymes and accumulated intermediates have been tested clinically. Here, we discuss the current understanding of mitochondria in cancer and the interactions between mitochondrial functions, immune responses, and oncogenesis. Furthermore, we discuss mitochondria as hopeful targets for cancer therapy, providing insights into the progression of future therapeutic strategies.

The Tricarboxylic Acid Cycle Metabolites for Cancer: Friend or Enemy

The tricarboxylic acid (TCA) cycle is capable of providing sufficient energy for the physiological activities under aerobic conditions. Although tumor metabolic reprogramming places aerobic glycolysis in a dominant position, the TCA cycle remains indispensable for tumor cells as a hub for the metabolic linkage and interconversion of glucose, lipids, and certain amino acids. TCA intermediates such as citrate, α-ketoglutarate, succinate, and fumarate are altered in tumors, and they regulate the tumor metabolism, signal transduction, and immune environment to affect tumorigenesis and tumor progression. This article provides a comprehensive review of the modifications occurring in tumor cells in relation to the intermediates of the TCA cycle, which affects tumor pathogenesis and current therapeutic strategy for therapy through targeting TCA cycle in cancer cells.

Pan-cancer analysis implicates novel insights of lactate metabolism into immunotherapy response prediction and survival prognostication

BACKGROUND

Immunotherapy has emerged as a potent clinical approach for cancer treatment, but only subsets of cancer patients can benefit from it. Targeting lactate metabolism (LM) in tumor cells as a method to potentiate anti-tumor immune responses represents a promising therapeutic strategy.

METHODS

Public single-cell RNA-Seq (scRNA-seq) cohorts collected from patients who received immunotherapy were systematically gathered and scrutinized to delineate the association between LM and the immunotherapy response. A novel LM-related signature (LM.SIG) was formulated through an extensive examination of 40 pan-cancer scRNA-seq cohorts. Then, multiple machine learning (ML) algorithms were employed to validate the capacity of LM.SIG for immunotherapy response prediction and survival prognostication based on 8 immunotherapy transcriptomic cohorts and 30 The Cancer Genome Atlas (TCGA) pan-cancer datasets. Moreover, potential targets for immunotherapy were identified based on 17 CRISPR datasets and validated via in vivo and in vitro experiments.

RESULTS

The assessment of LM was confirmed to possess a substantial relationship with immunotherapy resistance in 2 immunotherapy scRNA-seq cohorts. Based on large-scale pan-cancer data, there exists a notably adverse correlation between LM.SIG and anti-tumor immunity as well as imbalance infiltration of immune cells, whereas a positive association was observed between LM.SIG and pro-tumorigenic signaling. Utilizing this signature, the ML model predicted immunotherapy response and prognosis with an AUC of 0.73/0.80 in validation sets and 0.70/0.87 in testing sets respectively. Notably, LM.SIG exhibited superior predictive performance across various cancers compared to published signatures. Subsequently, CRISPR screening identified LDHA as a pan-cancer biomarker for estimating immunotherapy response and survival probability which was further validated using immunohistochemistry (IHC) and spatial transcriptomics (ST) datasets. Furthermore, experiments demonstrated that LDHA deficiency in pancreatic cancer elevated the CD8+ T cell antitumor immunity and improved macrophage antitumoral polarization, which in turn enhanced the efficacy of immunotherapy.

CONCLUSIONS

We unveiled the tight correlation between LM and resistance to immunotherapy and further established the pan-cancer LM.SIG, holds the potential to emerge as a competitive instrument for the selection of patients suitable for immunotherapy.