Intratumoral Copper Modulates PD-L1 Expression and Influences Tumor Immune Evasion

Integrating cuproptosis and immunosenescence: A novel therapeutic strategy in cancer treatment

Recent advancements in our understanding of cell death mechanisms have progressed beyond traditional apoptosis to encompass various forms of regulated cell death, notably cuproptosis. This copper-dependent cell death occurs when copper interacts with lipoylated enzymes in the tricarboxylic acid cycle, leading to protein aggregation and subsequent cell death. Alongside this, immunosenescence the gradual decline in immune function due to aging has emerged as a significant factor in cancer progression and response to treatment. Innovative strategies that integrate cuproptosis and immunosenescence are showing considerable promise in cancer therapy. By leveraging the altered copper metabolism in cancer cells, cuproptosis can selectively induce cell death, effectively targeting and eliminating tumors. Simultaneously, addressing immunosenescence can rejuvenate the aging immune system, enhancing its capacity to identify and destroy cancer cells. This dual approach creates a synergistic effect, optimizing therapeutic efficacy by directly attacking tumor cells while revitalizing the immune response. Such integration bolsters the defense against cancer progression and recurrence and holds great potential for advancing cancer treatment modalities and improving patient outcomes. This paper delves into the interactions between cuproptosis and immunosenescence, emphasizing their implications for developing innovative cancer therapies.

Zonated Copper-Driven Breast Cancer Progression Countered by a Copper-Depleting Nanoagent for Immune and Metabolic Reprogramming

While studies of various carcinomas have reported aberrant metal metabolism, much remains unknown regarding their spatial accumulation and regulatory impacts in tumors. Here, elevated copper levels are detected in breast cancer tumors from patients and animal models, specifically exhibiting a zonate spatial pattern. Spatially resolved multiomics analyses reveal that copper zonation drives a tumor metabolic preference for oxidative phosphorylation (OXPHOS) over glycolysis and promotes tumor metastatic and immune-desert phenotypes. Then, a copper-depleting nanoagent is developed based on copper chelator tetrathiomolybdate (TM)-loaded hybridized bacterial outer membrane vesicles (hOMVs) from both Akkermansia muciniphila bacteria and CD326-targeting peptide-engineered Escherichia coli (TM@CD326hOMV). Systemic administration of TM@CD326hOMV reduces the labile copper level in tumors and inhibits both tumor growth and metastatic phenotypes, specifically through metabolic reprograming of OXPHOS toward glycolysis and restoration of antitumor immunity responses involving natural killer cells, CD4+ T cells, and cytotoxic CD8+ T cells in tumors. Assessing survival in murine breast cancer models, a combination of TM@CD326hOMV and a checkpoint blockade agent outperforms monotherapies. Notably, a copper-rich diet undermines the therapeutic efficacy of TM@CD326hOMV. Beyond demonstrating an effective nanoagent for treating breast cancer, this study deepens the understanding of how the pattern of copper accumulation in tumors affects pathophysiology and immunity.

Research progress on cuproptosis and copper related anti-tumor therapy

Copper is a trace element which is essential for biological organisms, and its homeostatic balance is important for living organisms to maintain the normal function. When the copper homeostasis is disordered, the cellular function and structure will be disrupted. Excess copper cause oxidative stress and DNA damage in cells, thereby inducing regulated cell death such as apoptosis and necroptosis. Excess copper in mitochondria can bind to lipoylated proteins in the tricarboxylic acid (TCA) cycle and cause them to aggregate, resulting in proteotoxic stress and eliciting a novel cell death modality: cuproptosis. Cancer cells have a greater demand for copper compared to normal tissue, and high levels of copper ions are closely associated with tumour proliferation and metastasis. The anti-tumor mechanisms of copper include the production of oxidative stress, inhibition of the ubiquitin-proteasome system, suppression of angiogenesis, and induction of copper-dependent cell death. Targeting copper is one of the current directions in oncology research, including the use of copper ion carriers to increase intracellular copper levels to induce oxidative stress and cuproptosis, as well as the use of copper ion chelators to reduce copper bioavailability. However, copper complexes have certain toxicity, so their biosafety needs to be improved. Emerging nanotechnology is expected to solve this problem by utilizing copper-based nanomaterials (Cu-based NMs) to deliver copper ions and a variety of drugs with different functions, thereby improving the anti-tumor efficacy and reducing the side effects. Therefore, a thorough understanding of copper metabolic processes and the mechanism of cuproptosis will greatly benefit anti-tumor therapy. This review summarizes the processes of copper metabolism and the mechanism of cuproptosis. In addition, we discuss the current anti-tumor paradigms related to copper, we also discuss current nanotherapeutic approaches to copper mortality and provide prospective insights into the future copper-mediated cancer therapy.

Copper Depletion in Tumors Boosts Immunotherapy

Copper depletion is being billed as a viable approach for cancer treatment. Vittorio and co-workers successfully demonstrated that Cuprior, an FDA-approved drug that binds with copper, effectively enhances anti-GD2 immunotherapy and improves the responses for neuroblastoma patients. These findings highlight the important role of copper chelation in modulating the tumor microenvironment. This study presented a novel approach to potentiate immunotherapies for neuroblastoma patients, warranting further investigations into copper depletion as a potential adjuvant therapy for other tumors.

Comprehensive analysis of prognosis and tumor immune microenvironment of cuproptosis-related gene CDKN2A in lung adenocarcinoma

BACKGROUND

Recent research has increasingly highlighted the significance of various forms of cell death in contributing to tumor heterogeneity and modulating anti-tumor immunity. However, the potential implications of cuproptosis-related genes (CRGs) in lung adenocarcinoma (LUAD) remains poorly explored.

METHODS

We conducted a comprehensive analysis of the expression profiles of 19 CRGs in LUAD based on The Cancer Genome Atlas (TCGA). Utilizing consensus clustering, we stratified the TCGA cohort into two distinct LUAD subtypes (Cluster 1 and Cluster 2). The expression of CDKN2A was further validated across multiple datasets, including TCGA, GEO, Cancer Cell Line Encyclopedia (CCLE), and the Human Protein Atlas (HPA). The prognostic value of the CDKN2A was evaluated through univariate, multivariate, and survival analyses. Gene set enrichment analysis (GSEA) was performed to elucidate the molecular mechanisms associated with the CDKN2A. Additionally, we assessed the levels of immune cell infiltration in LUAD using the CIBERSORT, ESTIMATE, and XCELL algorithms.

RESULTS

By systematically analyzing the genetic alterations of 19 CRGs in LUAD, we found 15 differentially expressed genes between LUAD and adjacent normal tissues. Subsequently, using the consensus clustering method, we classified LUAD patients into two molecular subtypes and cluster 2 had a poor prognosis. CDKN2A emerged as a key gene of interest, exhibiting elevated expression in LUAD and correlating with adverse patient outcomes. Moreover, immunoinfiltration analysis revealed differential levels of immune cell infiltration between the CDKN2A high and CDKN2A low expression groups.

CONCLUSIONS

Our findings indicate that CDKN2A may serve as an effective prognostic biomarker for LUAD and may offer valuable insights into potential immunotherapeutic strategies for these patients.

CLINICAL TRIAL NUMBER

Not applicable.

Plasma IgG and IgM autoantibodies to COPT1 as potential biomarkers for detection of non-small cell lung cancer

Background

Early diagnosis of lung cancer is crucial for improving patient outcomes. Autoantibodies against tumor-associated antigens (TAAs) found in the plasma can serve as biomarkers for lung cancer detection. Copper transporter 1 (COPT1) is abnormally expressed in several cancers including lung cancer. The purpose of this study is to explore the significance of anti-COPT1 autoantibodies in the clinical diagnosis of non-small cell lung cancer (NSCLC).

Methods

The expression level of COPT1 in NSCLC and normal tissues was analyzed based on TCGA and the Human Protein Atlas (HPA) database. Through enzyme-linked immunosorbent assay (ELISA), the expression levels of anti-COPT1 autoantibodies in plasma samples from normal controls (NC), patients with benign pulmonary nodules (BPN), and patients with NSCLC were detected in the discovery (89 NC and 89 NSCLC) and verification (321 NC, 321 BPN and 321 NSCLC) groups. The ELISA results were verified by western blotting and indirect immunofluorescence experiments.

Results

Based on HPA and TCGA databases, the mRNA and protein levels of COPT1 were higher in NSCLC tissues than in normal tissues. The levels of anti-COPT1-IgG and anti-COPT1-IgM autoantibodies were significantly higher in patients with NSCLC (P<0.05). Anti-COPT1-IgG and anti-COPT1-IgM could discriminate NSCLC from NC with area under the curve (AUC) values of 0.733 (95% CI: 0.694-0.771) and 0.679 (95% CI: 0.638-0.720), respectively. Additionally, the combination of anti-COPT1-IgG, anti-COPT1-IgM, and carcinoembryonic antigen (CEA) could enhance the efficacy of NSCLC diagnosis from BPN with increased AUC values.

Conclusions

Our study indicated the potential significance of anti-COPT1-IgG and anti-COPT1-IgM autoantibodies as novel biomarkers for the detection of NSCLC. Furthermore, the combination of anti-COPT1-IgG and anti-COPT1-IgM improved the diagnostic value.

Cuproplasia and cuproptosis in hepatocellular carcinoma: mechanisms, relationship and potential role in tumor microenvironment and treatment

BACKGROUND

Hepatocellular carcinoma (HCC) is the main phenotype of liver cancer with a poor prognosis. Copper is vital in liver function, and HCC cells rely on it for growth and metastasis, leading to cuproplasia. Excessive copper can induce cell death, termed cuproptosis. Tumor microenvironment (TME) is pivotal in HCC, especially in immunotherapy, and copper is closely related to the TME pathogenesis. However, how these two mechanisms contribute to the TME is intriguing.

MAIN BODY

We conducted the latest progress literature on cuproplasia and cuproptosis in HCC, and summarized their specific roles in TME and treatment strategies. The mechanisms of cuproplasia and cuproptosis and their relationship and role in TME have been deeply summarized. Cuproplasia fosters TME formation, angiogenesis, and metastasis, whereas cuproptosis may alleviate mitochondrial dysfunction and hypoxic conditions in the TME. Inhibiting cuproplasia and enhancing cuproptosis in HCC are essential for achieving therapeutic efficacy in HCC.

CONCLUSION

An in-depth analysis of cuproplasia and cuproptosis mechanisms within the TME of HCC unveils their opposing nature and their impact on copper regulation. Grasping the equilibrium between these two factors is crucial for a deeper understanding of HCC mechanisms to shed light on novel directions in treating HCC.

Copper in melanoma: At the crossroad of protumorigenic and anticancer roles

Copper is an essential micronutrient that is a cofactor for various enzymes involved in multiple cellular processes. Melanoma patients have high serum copper levels, and elevated copper concentrations are found in melanoma tumors. Copper influences the activity of several melanoma-related proteins involved in cell survival, proliferation, pigmentation, angiogenesis, and metastasis. Targeting these processes with copper chelators has shown efficacy in reducing tumor growth and overcoming drug resistance. In contrast, excessive copper can also have detrimental effects when imported into melanoma cells. Multiple distinct cellular effects of copper overload, including the induction of different types of cell death, have been reported. Cuproptosis, a novel type of copper-dependent cell death, has been recently described and is associated with the metabolic phenotype. Melanoma cells can switch between glycolysis and oxidative phosphorylation, which are crucial for tumor growth and drug resistance. In this respect, metabolic plasticity might be exploited for the use of copper-delivery strategies, including repurposing of disulfiram, which is approved for the treatment of noncancer patients. In addition, the development of nanomedicines can improve the targeted delivery of copper to melanoma cells and enable the use of these drugs alone or in combination as copper has been shown to complement targeted therapy and immunotherapy in melanoma cells. However, further research is needed to explore the specific mechanisms of both copper restriction and excess copper-induced processes and determine effective biomarkers for predicting treatment sensitivity in melanoma patients. In this review, we discuss the dual role of copper in melanoma biology.

Blocking copper transporter protein-dependent drug efflux with albumin-encapsulated Pt(IV) for synergistically enhanced chemo-immunotherapy

Non-small cell lung cancer (NSCLC) represents the most prevalent form of lung cancer, exerting a substantial impact on global health. Cisplatin-based chemotherapy is the standard treatment for NSCLC, but resistance and severe side effects present significant clinical challenges. Recently, novel tetravalent platinum compounds have attracted significant interest. While numerous studies concentrate on their functional modifications and targeted delivery, tumor-induced platinum resistance is frequently overlooked. Previous tetravalent platinum compound demonstrated antitumor activity, yet proved ineffective against cells exhibiting resistance to cisplatin. In order to enhance the efficacy and potential applications of tetravalent platinum in NSCLC, a glutathione (GSH)-responsive albumin nanoquadrivalent platinum (HSA@Pt) have been constructed. In light of previous research into drug conjugation, this study was to develop a combined chemo-immunotherapy approach. The HSA@Pt demonstrated high efficacy and low toxicity, with targeted tumor accumulation. Furthermore, Ammonium Tetrathiomolybdate (TM) has been demonstrated to exert a synergistic inhibitory effect on ATPase Copper Transporting Beta (ATP7B) and Programmed Death Ligand 1 (PD-L1), impede platinum efflux, induce cellular stress, and activate antitumor immunity. The findings suggest HSA@Pt's potential for clinical use and a novel chemo-immunotherapy strategy for NSCLC, enhancing the utility of established drugs through synergistic sensitization.

Silk Fibroin Nanoparticles for Enhanced Cuproptosis and Immunotherapy in Pancreatic Cancer Treatment

Cuproptosis is a newly discovered copper ion-dependent programmed cell death. Elesclomol (ES) is a Cu2+ transporter that delivers Cu2+ into tumor cells, causing cell death at toxic doses. However, ES has a short blood half-life, limiting its accumulation in tumors. This study introduces Tussah silk fibroin nanoparticles (TSF@ES-Cu NPs) to protect ES and Cu2+. TSF, with a stable structure, resists metabolism in circulation. Targeting tumors with natural RGD peptides and TSF's unique secondary structure, enhances drug enrichment and special release in pancreatic tumors, improving treatment efficacy. In vitro, TSF@ES-Cu induces tumor cell cuproptosis, releases DAMPs, promotes dendritic cells (DCs) maturation, and macrophage M1 polarization. In vivo, TSF@ES-Cu reshapes the tumor microenvironment (TME), increasing mature DCs from 22.7% to 43.3%, CD8+ T cells from 5.08% to 17.1%, and reducing M2 macrophages from 50.7% to 18.4%. Additionally, the combined anti-tumor efficacy of TSF@ES-Cu and αPDL-1 is 1.6 times higher than TSF@ES-Cu alone and 2.5 times higher than αPDL-1 alone. In summary, this study reports that the combination of TSF@ES-Cu and αPDL-1 effectively induces cuproptosis and reshapes the TME, offering a new approach for copper nanomaterial-based tumor immunotherapy.

Enhanced effect of radiofrequency ablation on HCC by siRNA-PD-L1-endostatin Co-expression plasmid delivered

Hepatocellular carcinoma (HCC) poses a significant clinical challenge due to high mortality and limited treatment options. Radiofrequency ablation (RFA) is commonly used but can be limited by tumor recurrence. This study explores the potential of combining RFA with an attenuated Salmonella strain carrying siRNA-PD-L1 and endostatin to enhance HCC treatment. In this study, an H22 subcutaneous tumor mouse model was used, with animals divided into five groups for treatment with a blank control, a blank Salmonella plasmid, RFA alone, siRNA-PD-L1-endostatin, or a combination of RFA and siRNA-PD-L1-endostatin. The combination therapy significantly reduced tumor growth, angiogenesis, and PD-L1/VEGF expression in tumor tissues post-RFA. Additionally, it induced tumor cell apoptosis, inhibited proliferation and migration, and increased the infiltration of T lymphocytes, granzyme B+T cells, and CD86+macrophages within tumors. There was also a notable rise in T and NK cell populations in the spleen. In conclusion, combining RFA with siRNA-PD-L1-endostatin delivered by attenuated Salmonella synergistically enhances anti-tumor effects, boosts the anti-tumor immune response, and improves RFA efficacy for HCC.

Targeting mineral metabolism in cancer: Insights into signaling pathways and therapeutic strategies

Cancer remains the second leading cause of death worldwide, emphasizing the critical need for effective treatment and control strategies. Essential minerals such as copper, iron, zinc, selenium, phosphorous, calcium, and magnesium are integral to various biological processes and significantly influence cancer progression through altered metabolic pathways. For example, dysregulated copper levels promote tumor growth, while cancer cells exhibit an increased dependency on iron for signaling and redox reactions. Zinc influences tumor development through pathways such as Akt-p21. Selenium, primarily through its role in selenoproteins, exhibits anticancer potential but may also contribute to tumor progression. Similarly, dietary phosphate exacerbates tumorigenesis, metastasis, and angiogenesis through signaling pathway activation. Calcium, the most abundant mineral in the body, is tightly regulated within cells, and its dysregulation is a hallmark of various cancers. Magnesium deficiency, on the other hand, promotes cancer progression by fostering inflammation and free radical-induced DNA mutations. Interestingly, magnesium also plays a dual role, with low levels enhancing epithelial-mesenchymal transition (EMT), a critical process in cancer metastasis. This complex interplay of essential minerals underscores their potential as therapeutic targets. Dysregulation of these minerals and their pathways could be exploited to selectively target cancer cells, offering novel therapeutic strategies. This review summarizes current research on the abnormal accumulation or depletion of these microelements in tumor biology, drawing evidence from animal models, cell lines, and clinical samples. We also highlight the potential of these minerals as biomarkers for cancer diagnosis and prognosis, as well as therapeutic approaches involving metal chelators, pharmacological agents, and nanotechnology. By highlighting the intricate roles of these minerals in cancer biology, we aim to inspire further research in this critical yet underexplored area of oncology.

Impact of cuproptosis in gliomas pathogenesis with targeting options

Gliomas constitute the most prevalent primary central nervous system tumors, often characterized by complex metabolic profile, genomic instability, and aggressiveness, leading to frequent relapse and high mortality rates. Traditional treatments are commonly ineffective because of gliomas increased heterogeneity, invasive characteristics and resistance to chemotherapy. Among several pathways affecting cellular homeostasis, cuproptosis has recently emerged as a novel type of programmed cell death, triggered by accumulation of copper ions. Although the precise molecular mechanisms of cuproptosis are not fully elucidated, there is evidence that copper ions can target mitochondrial lipoylated proteins, disrupting the tricarboxylic acid cycle and electron transport chain, thus leading to deregulated mitochondrial metabolism, protein aggregation and cell death. Of importance, altered expression of copper transporters and abnormally high intracellular copper levels have been observed in several cancer types, including gliomas, contributing to tumor growth and metastasis. Furthermore, a range of prognostic models incorporating cuproptosis-related genes and lncRNAs have been proposed and are currently under clinical validation. Drugs modulating cuproptosis or interfering with copper-binding proteins are under development, causing metabolic failure and cell death, thus offering potential new avenues for glioma diagnosis and therapy. In this article, we explore the role of copper metabolism in gliomas and the potential synergistic effects of cuproptosis-based treatments with current therapies, in effective targeting of tumor progression and chemoresistance.

AKT1 Phosphorylates FDX1 to Promote Cuproptosis Resistance in Triple-Negative Breast Cancer

Cuproptosis, a recently defined copper-dependent cell death pathway, remains largely unexplored in tumor therapies, particularly in breast cancer. This study demonstrates that triple-negative breast cancer (TNBC) bears a relatively elevated copper levels and exhibits resistance to cuproptosis. Mechanistically, copper activates the AKT signaling pathway, which inhibits ferredoxin-1 (FDX1), a key regulator of cuproptosis. AKT1-mediated FDX1 phosphorylation not only abrogates FDX1-induced cuproptosis and aerobic respiration but also promotes glycolysis. Consequently, the combination of AKT1 inhibitors and the copper ionophores synergistically alleviate TNBC tumorigenesis both in vitro and in vivo. In summary, the findings reveal a crucial mechanism underlying TNBC resistance to cuproptosis and suggest a potential therapeutic approach for TNBC.

A prognostic model for lung adenocarcinoma based on cuproptosis and disulfidptosis related genes revealing the key prognostic role of FURIN

Lung adenocarcinoma (LUAD) is the most common subtype of lung cancer. Despite advances in treatment, the prognosis remains poor due to late diagnosis. Cuproptosis (driven by copper ion accumulation) and disulfidptosis (driven by disulfide bond accumulation) are novel forms of programmed cell death, closely linked to tumor initiation, progression, and resistance. However, the specific roles of these mechanisms in LUAD remain inadequately studied. This study integrated multi-omics data from TCGA and GEO databases to systematically evaluate the differential expression and prognostic significance of copper and disulfide-related genes (DCRGs), identify two DCRG molecular subtypes, and construct a DCRG scoring model based on four key genes. Multi-omics analysis results revealed that the DCRG score not only accurately predicts prognosis in LUAD patients but is also closely associated with immune cell infiltration patterns and EGFR inhibitor responses. RT-qPCR validated the high expression of FURIN and RHOV in LUAD cells, supporting their role as potential therapeutic targets. Further Mendelian randomization analysis confirmed the causal relationship between FURIN and LUAD development. These findings provide novel biomarkers for the prognosis evaluation of LUAD based on cuproptosis and disulfidptosis mechanisms and offer a theoretical basis for targeting FURIN in LUAD treatment.

Diethyldithiocarbamate-copper complex ignites the tumor microenvironment through NKG2D-NKG2DL axis

Advanced metastatic colorectal cancer (CRC) with deficient DNA mismatch repair (MMR-d), or immune-hot CRCs, show significantly improved clinical outcomes compared to MMR-proficient (MMR-p), or immune-cold CRCs. While the prior represents about 5% of all CRCs, the latter represent 95% and are characterized by low immunogenicity. This study investigates bis-diethyldithiocarbamate (CuET), a novel anticancer compound, and its impact on the colorectal cancer tumor microenvironment (TME). CuET is shown to convert immunologically inactive tumors into hotbeds of antitumor immune responses, marked by increased lymphocyte infiltration, heightened cytotoxicity of natural killer (NK) and T cells, and enhanced non-self recognition by lymphocytes. The potent anticancer cytotoxicity and in vivo safety and efficacy of CuET are established. In summary, CuET transforms the colorectal cancer TME, bolstering NK and T cell cytotoxicity and refining tumor cell recognition through non-classical activation via the NKG2D/NKG2DL axis. This study unveils a novel mechanism of action for CuET: a potent immunomodulator capable of turning cold tumors hot.

Prion protein promotes copper toxicity in Wilson disease

Copper (Cu) is a vitally important micronutrient, whose balance between essential and toxic levels requires a tightly regulated network of proteins. Dysfunction in key components of this network leads to the disruption of Cu homeostasis, resulting in fatal disorders such as Wilson disease, which is caused by mutations in the hepatic Cu efflux transporter ATP7B. Unfortunately, the molecular targets for normalizing Cu homeostasis in Wilson disease remain poorly understood. Here, using genome-wide screening, we identified the cellular prion protein (PrP) as an important mediator of Cu toxicity in WD. Loss of ATP7B stimulates hepatic expression of PrP, which promotes endocytic Cu uptake, leading to toxic Cu overload. Suppression of PrP significantly reduces Cu toxicity in cell and animal models of Wilson disease. These findings highlight the critical regulatory role of PrP in copper metabolism and open new avenues for exploring the therapeutic potential of PrP suppression in Wilson disease.

Cuproptosis: A new mechanism for anti-tumour therapy

As an indispensable trace metal element in the organism, copper acts as a key catalytic cofactor in a wide range of biological processes. Copper homeostasis disorders can be caused by either copper excess or deficiency, and copper homeostasis disorders will affect the normal physiological functions of cells and induce cell death through a variety of mechanisms, such as the emerging cuproptosis model. The imbalance of copper homeostasis will lead to the occurrence of cancer, and copper is a key factor in cell signalling, so copper is involved in the development of cancer by promoting cell proliferation, angiogenesis and metastasis, etc. The therapeutic role of Cuproptosis as a hotspot of research in cancer has also attracted much attention. Therefore, this paper comprehensively searches the literature to review the roles and mechanisms of Cuproptosis in the treatment of malignant tumours, aiming to provide new insights into the role and mechanism of Cuproptosis in anti-malignant tumour therapy and present novel ideas and methods.

Involvement of copper in cell death and cancer

Copper (cu) is an essential micronutrient required for numerous metabolic processes. It plays a crucial role in cellular respiration by participating in the electron transport chain and facilitating numerous biological reactions. Various diseases, including cancer, demonstrate localized elevation of copper levels and/or alterations in the overall distribution of copper. Modulating local or systemic copper levels as a novel therapeutic approach for treating and ameliorating diseases has emerged as a prominent trend in disease management, particularly in the realm of cancer therapy, which is currently under investigation. The objective of this review is to offer a thorough examination of copper metabolism in both physiological and pathological contexts. Specifically, it delves into how copper ions can effectively target and stimulate tumor cell death via the process known as cuproptosis in cancer patients. Furthermore, this review explores the utilization of three categories of anticancer medications (copper ion carriers, copper complexes, and copper chelating agents) pertaining to copper metabolism within the realm of cancer therapy, elucidating on the distinct mechanisms through which they exert their effects.

Targeting regulated cell death: Apoptosis, necroptosis, pyroptosis, ferroptosis, and cuproptosis in anticancer immunity

In the evolving landscape of cancer treatment, the strategic manipulation of regulated cell death (RCD) pathways has emerged as a crucial component of effective anti-tumor immunity. Evidence suggests that tumor cells undergoing RCD can modify the immunogenicity of the tumor microenvironment (TME), potentially enhancing its ability to suppress cancer progression and metastasis. In this review, we first explore the mechanisms of apoptosis, necroptosis, pyroptosis, ferroptosis, and cuproptosis, along with the crosstalk between these cell death modalities. We then discuss how these processes activate antigen-presenting cells, facilitate the cross-priming of CD8+ T cells, and trigger anti-tumor immune responses, highlighting the complex effects of novel forms of tumor cell death on TME and tumor biology. Furthermore, we summarize potential drugs and nanoparticles that can induce or inhibit these emerging RCD pathways and their therapeutic roles in cancer treatment. Finally, we put forward existing challenges and future prospects for targeting RCD in anti-cancer immunity. Overall, this review enhances our understanding of the molecular mechanisms and biological impacts of RCD-based therapies, providing new perspectives and strategies for cancer treatment.

Advances in non-apoptotic regulated cell death: implications for malignant tumor treatment

Cell death mechanisms are broadly classified into accidental cell death (ACD) and regulated cell death (RCD). ACD such as necrosis, is an uncontrolled, accidental process, while RCD is tightly regulated by specific signaling pathways and molecular mechanisms. Tumor cells are characterized by their ability to evade cell death and sustain uncontrolled proliferation. The failure of programmed cell death is a key contributor to tumor initiation, progression, and resistance to cancer therapies. Traditionally, research has focused primarily on apoptosis as the dominant form of RCD in cancer. However, emerging evidence highlights the importance of other non-apoptotic forms of RCD, such as pyroptosis, ferroptosis, necroptosis, and parthanatos, in tumorigenesis and treatment response. These pathways are gaining attention for their potential roles in overcoming therapy resistance. In this review, we will discuss the recent advances in the study of non-apoptotic cell death pathways in malignant tumors and explore their therapeutic implications, offering insights into new targets for cancer treatment strategies.

Cuproplasia and cuproptosis, two sides of the coin

Copper is an essential micronutrient in the human body, mainly acting as a crucial cofactor required for a wide range of physiological processes across nearly all cell types. Recent advances revealed that tumor cells seize copper to fulfill their rapid proliferation, metastasis, immune evasion, and so on by reprogramming the copper regulatory network, defined as cuproplasia. Thus, targeting copper chelation to reduce copper levels has been considered a rational tumor therapy strategy. However, overloaded copper ions could be toxic, which leads to the aggregation of lipoylated mitochondrial proteins and the depletion of iron-sulfur clusters, ultimately resulting in cell death, termed cuproptosis. Upon its discovery, cuproptosis has attracted great interest from oncologists, and targeting cuproptosis by copper ionophores exhibits as a potential anti-tumor therapy. In this review, we present the underlying mechanisms involved in cuproplasia and cuproptosis. Additionally, we sum up the chemicals targeting either cuproplasia or cuproptosis for cancer therapy. Further attention should be paid to distinguishing cancer patients who are suitable for targeting cuproplasia or cuproptosis.

Cuproptosis: molecular mechanisms, cancer prognosis, and therapeutic applications

Cuproptosis differs from other forms of cell death, such as apoptosis, necroptosis, and ferroptosis, in its unique molecular mechanisms and signaling pathways. In this review, we delve into the cellular metabolic pathways of copper, highlighting the role of copper in biomolecule synthesis, mitochondrial respiration, and antioxidant defense. Furthermore, we elucidate the relationship between cuproptosis-related genes (CRGs) and cancer prognosis, analyzing their expression patterns across various tumor types and their impact on patient outcomes. Our review also uncovers the potential therapeutic applications of copper chelators, copper ionophores, and copper-based nanomaterials in oncology. In addition, we discuss the emerging role of cuproptosis in remodeling the tumor microenvironment, enhancing immune cell infiltration, and converting "cold tumors" into "hot tumors" that respond better to immunotherapy. In short, this review underscores the pivotal importance of cuproptosis in cancer biology and highlights its translational potential as a novel therapeutic target.

Intrinsic PD-L1 Degradation Induced by a Novel Self-Assembling Hexapeptide for Enhanced Cancer Immunotherapy

Programmed death-ligand 1 (PD-L1) is a critical immune checkpoint protein that facilitates tumor immune evasion. While antibody-based PD-1/PD-L1 inhibitors have shown promise, their limitations necessitate the development of alternative therapeutic strategies. This work addresses these challenges by developing a hexapeptide, KFM (Lys-Phe-Met-Phe-Met-Lys), capable of both directly downregulating PD-L1 and self-assembling into a ROS-responsive supramolecular hydrogel. This dual functionality allows Gel KFM to function as a localized drug delivery system and a PD-L1 inhibitor. Loading the hydrogel with mitoxantrone (MTX) and metformin (MET) further enhances the therapeutic effect by combining chemotherapy with PD-L1 downregulation. In vitro and in vivo studies demonstrate significant tumor growth inhibition, increased CD8+ T cell infiltration, and reduced intratumoral PD-L1 expression following peritumoral administration. Mechanistically, KFM promotes PD-L1 degradation via a ubiquitin-dependent pathway. This "carrier-free" delivery system expands the role of supramolecular hydrogels beyond passive carriers to active immunotherapeutic agents, offering a promising new strategy for cancer therapy.

A Smart Nanomedicine Unleashes a Dual Assault of Glucose Starvation and Cuproptosis to Supercharge αPD-L1 Therapy

Combination therapy has become a promising strategy for promoting the outcomes of anti-programmed death ligand-1 (αPD-L1) therapy in lung cancer. Among all, emerging strategies targeting cancer metabolism have shown great potency in treating cancers with immunotherapy. Here, alteration in glucose and copper metabolisms is found to synergistically regulate PD-L1 expression in lung cancer cells. Thus, an intelligent biomimetic nano-delivery system is synthesized by camouflaging lung cancer cell membranes onto glucose oxidase-loaded Cu-LDHs (CMGCL) for cancer metabolism targeted interference. Such novel nanomedicine is able to induce lung cancer cell cuproptosis and PD-L1 upregulation significantly via self-amplified cascade reactions. Meanwhile, with a decent cancer cell membrane coating, CMGCL exhibited great biosafety, tumor-targeted efficiency and anti-tumor effects in LLC lung tumor-bearing mice models. Additionally, a combination of CMGCL can sensitize the therapeutic effects of αPD-L1, substantially promoting tumor inhibition in both subcutaneous and lung metastasis LLC-bearing mice models. Overall, these findings highlight the potential connections between glucose metabolism and cell cuproptosis, offering a promising approach for treating lung cancer by integrating starvation, cuproptosis, and immunotherapy.

Cuproplasia-related gene signature: Prognostic insights for glioma therapy

Background

Adult-type diffuse gliomas encompass nearly a quarter of all primary tumors found in the CNS, including astrocytoma, oligodendroglioma, and glioblastoma. Histopathological tumor grade and molecular profile distinctly impact patient survival. Despite treatment advancements, patients with recurrent glioma have a very poor clinical outcome, warranting improved risk stratification to determine therapeutic interventions. Various studies have shown that copper is a notable trace element that is crucial for biological processes and has been shown to display pro-tumorigenic functions in cancer, particularly gliomas.

Methods

Differential gene expression, Cox regression, and least absolute shrinkage and selection operator regression were used to identify 19 copper-homeostasis-related gene signatures using TCGA lower-grade glioma and glioblastoma (GBM) cohorts. The GLASS Consortium dataset was used as an independent validation cohort. Enrichment analysis revealed the involvement of the signature in various cancer-related pathways and biological processes. Using this CHRG signature, a risk score model and a nomogram were developed to predict survival in glioma patients.

Results

Our prognostic CHRG signature stratified patients into high- and low-risk groups, demonstrating robust predictive performance. High-risk groups showed poorer survival outcomes. The nomogram model integrating CHRG signature and clinical features accurately predicted 1-, 3-, and 5-year survival rates in both training and test sets.

Conclusions

The identified 19-gene CHRG signature holds promise as a prognostic tool, enabling accurate risk stratification and survival prediction in glioma patients. Integrating this signature with clinical characteristics enhances prognostic accuracy, underscoring its potential clinical utility in optimizing therapeutic strategies and patient care in glioma management.

Mammalian copper homeostasis: physiological roles and molecular mechanisms

In the past decade, evidence for the numerous roles of copper (Cu) in mammalian physiology has grown exponentially. The discoveries of Cu involvement in cell signaling, autophagy, cell motility, differentiation, and regulated cell death (cuproptosis) have markedly extended the list of already known functions of Cu, such as a cofactor of essential metabolic enzymes, a protein structural component, and a regulator of protein trafficking. Novel and unexpected functions of Cu transporting proteins and enzymes have been identified, and new disorders of Cu homeostasis have been described. Significant progress has been made in the mechanistic studies of two classic disorders of Cu metabolism, Menkes disease and Wilson's disease, which paved the way for novel approaches to their treatment. The discovery of cuproptosis and the role of Cu in cell metastatic growth have markedly increased interest in targeting Cu homeostatic pathways to treat cancer. In this review, we summarize the established concepts in the field of mammalian Cu physiology and discuss how new discoveries of the past decade expand and modify these concepts. The roles of Cu in brain metabolism and in cell functional speciation and a recently discovered regulated cell death have attracted significant attention and are highlighted in this review.

Cuproptosis: a promising new target for breast cancer therapy

Breast cancer (BC) is the leading cause of cancer-related mortality among women globally, affecting approximately one-quarter of all female cancer patients and accounting for one-sixth of cancer-related deaths in women. Despite significant advancements in diagnostic and therapeutic approaches, breast cancer treatment remains challenging due to issues such as recurrence and metastasis. Recently, a novel form of regulated cell death, termed cuproptosis, has been identified. This process disrupts mitochondrial respiration by targeting the copper-dependent cellular pathways. The role of cuproptosis has been extensively investigated in various therapeutic contexts, including chemotherapy, immunotherapy, radiotherapy, and nanotherapy, with the development of novel drugs significantly improving clinical outcomes. This article aims to further elucidate the connection between cuproptosis and breast cancer, focusing on its therapeutic targets, signaling pathways, and potential biomarkers that could enhance treatment strategies. These insights may offer new opportunities for improved patient care and outcomes in breast cancer therapy.

Copper chelation redirects neutrophil function to enhance anti-GD2 antibody therapy in neuroblastoma

Anti-disialoganglioside (GD2) antibody therapy has provided clinical benefit to patients with neuroblastoma however efficacy is likely impaired by the immunosuppressive tumor microenvironment. We have previously defined a link between intratumoral copper levels and immune evasion. Here, we report that adjuvant copper chelation potentiates anti-GD2 antibody therapy to confer durable tumor control in immunocompetent models of neuroblastoma. Mechanistic studies reveal copper chelation creates an immune-primed tumor microenvironment through enhanced infiltration and activity of Fc-receptor-bearing cells, specifically neutrophils which are emerging as key effectors of antibody therapy. Moreover, we report copper sequestration by neuroblastoma attenuates neutrophil function which can be successfully reversed using copper chelation to increase pro-inflammatory effector functions. Importantly, we repurpose the clinically approved copper chelating agent Cuprior as a non-toxic, efficacious immunomodulatory strategy. Collectively, our findings provide evidence for the clinical testing of Cuprior as an adjuvant to enhance the activity of anti-GD2 antibody therapy and improve outcomes for patients with neuroblastoma.

Construction of a prognostic model based on cuproptosis-related genes and exploration of the value of DLAT and DLST in the metastasis for non-small cell lung cancer

BACKGROUND

To reveal the clinical value of cuproptosis-related genes on prognosis and metastasis in non-small cell lung cancer.

METHODS

Gene expression profiles and clinical information of non-small cell lung cancer were downloaded from The Cancer Genome Atlas and Gene Expression Omnibus databases. The data were grouped into training set, internal testing set, and external testing set. A risk prognostic model was constructed by Lasso-Cox regression analysis. Hub genes were identified and evaluated using immunohistochemistry and the transwell migration assay in 50 clinical patients.

RESULTS

A total of 17/19 cuproptosis-related genes were differentially expressed in tumors, 8 were significantly associated with prognosis, and 4 were markedly associated with metastasis. A risk model based on 2 cuproptosis-related genes was constructed and validated for predicting overall survival. The risk score was proven to be an independent risk factor for the prognosis of non-small cell lung cancer. Dihydrolipoamide S-acetyltransferase and dihydrolipoamide S-succinyltransferase, key genes in cuproptosis, were proven to be associated with non-small cell lung cancer prognosis and metastasis. Immunohistochemistry showed that their expression significantly predicted metastasis but failed to predict prognosis in non-small cell lung cancer patients. The transwell migration assay further increased the cellular reliability of our findings.

CONCLUSION

The cuproptosis-related genes prognostic model effectively predicted the prognosis of non-small cell lung cancer. Dihydrolipoamide S-acetyltransferase and dihydrolipoamide S-succinyltransferase may serve as predictive markers for metastasis in non-small cell lung cancer.

Targeting cuproptosis with nano material: new way to enhancing the efficacy of immunotherapy in colorectal cancer

Colorectal cancer has emerged as one of the predominant malignant tumors globally. Immunotherapy, as a novel therapeutic methodology, has opened up new possibilities for colorectal cancer patients. However, its actual clinical efficacy requires further enhancement. Copper, as an exceptionally crucial trace element, can influence various signaling pathways, gene expression, and biological metabolic processes in cells, thus playing a critical role in the pathogenesis of colorectal cancer. Recent studies have revealed that cuproptosis, a novel mode of cell death, holds promise to become a potential target to overcome resistance to colorectal cancer immunotherapy. This shows substantial potential in the combination treatment of colorectal cancer. Conveying copper into tumor cells via a nano-drug delivery system to induce cuproptosis of colorectal cancer cells could offer a potential strategy for eliminating drug-resistant colorectal cancer cells and vastly improving the efficacy of immunotherapy while ultimately destroy colorectal tumors. Moreover, combining the cuproptosis induction strategy with other anti-tumor approaches such as photothermal therapy, photodynamic therapy, and chemodynamic therapy could further enhance its therapeutic effect. This review aims to illuminate the practical significance of cuproptosis and cuproptosis-inducing nano-drugs in colorectal cancer immunotherapy, and scrutinize the current challenges and limitations of this methodology, thereby providing innovative thoughts and references for the advancement of cuproptosis-based colorectal cancer immunotherapy strategies.

Multi-omics analysis reveals the unique landscape of DLD in the breast cancer tumor microenvironment and its implications for immune-related prognosis

Background

Cuproptosis, i.e., copper-induced programmed cell death, has potential implications in cancer therapy. However, the impact of the cuproptosis-related gene (CRG) dihydrolipoyl dehydrogenase (DLD) on breast cancer (BC) prognosis remains underexplored.

Methods

We employed real-time quantitative PCR and multiplexed immunostaining techniques to quantify DLD expression in both BC and the adjacent non-cancerous tissues. Immunofluorescence analysis was employed to assess the influence of DLD on immune cells and immunological checkpoints in the BC microenvironment. DLD knockdown experiments were conducted in BC cell lines MDA-MB-468 and SK-BR-3, with knockdown efficiency validated via western blot. Subsequently, we performed the cell counting kit-8 (CCK-8) assay, clone formation assay, Transwell migration assay, and invasion assay. To construct a prognostic model, we employed a Lasso-Cox regression analysis of immune-related genes associated with DLD. Additionally, we established a competing endogenous RNA network based on CRGs to evaluate potential regulatory pathways.

Results

Compared to the adjacent tissues, BC tissues exhibited markedly elevated DLD expression levels. In vitro experiments demonstrated that DLD knockdown effectively inhibited BC cell migration, invasion, and proliferation. DLD exhibited positive correlations with CD68+ macrophages and PD-L1 in the tumor, as well as with macrophages and CD4+ T cells in the stroma. Tumor regions with high DLD expression were enriched in PD-L1 and macrophages, while stromal regions with high DLD expression contained CD4+ T cells and macrophages. The AUC values for 1-, 3-, and 5-year overall survival in TCGA-BRCA training set were 0.67, 0.66, and 0.66, respectively. A nomogram with a C-index of 0.715 indicated that risk score, tumor stage, and age could serve as independent prognostic factors for BC.

Conclusion

Our findings underscore the significant predictive significance of DLD in BC and its influence on the tumor microenvironment. DLD represents a promising diagnostic and prognostic marker for BC, offering novel avenues for the identification of therapeutic targets and the enhancement of immunotherapy in BC.

Intracellular zinc protects tumours from T cell-mediated cytotoxicity

Tumour immune evasion presents a significant challenge to the effectiveness of cancer immunotherapies. Recent advances in high-throughput screening techniques have uncovered that loss of antigen presentation and cytokine signalling pathways are central mechanisms by which tumours evade T cell immunity. To uncover additional vulnerabilities in tumour cells beyond the well-recognized antigen presentation pathway, we conducted a genome-wide CRISPR/Cas9 screen to identify genes that mediate resistance to chimeric-antigen receptor (CAR)-T cells, which function independently of classical antigen presentation. Our study revealed that loss of core-binding factor subunit beta (CBFβ) enhances tumour cell resistance to T cell killing, mediated through T cell-derived TNF. Mechanistically, RNA-sequencing and elemental analyses revealed that deletion of CBFβ disrupts numerous pathways including those involved in zinc homoeostasis. Moreover, we demonstrated that modulation of cellular zinc, achieved by supplementation or chelation, significantly altered tumour cell susceptibility to TNF by regulating the levels of inhibitor of apoptosis proteins. Consistent with this, treatment of tumour cells with a membrane-permeable zinc chelator had no impact on tumour cell viability alone, but significantly increased tumour cell lysis by CD8+ T cells in a TNF-dependent but perforin-independent manner. These results underscore the crucial role of intracellular zinc in regulating tumour cell susceptibility to T cell-mediated killing, revealing a novel vulnerability in tumour cells that might be exploited for the development of future cancer immunotherapeutics.

Prognostic Significance and Immune Landscape of a Cuproptosis-Related LncRNA Signature in Ovarian Cancer

Background: Cuproptosis is a copper-induced mitochondrial cell death, and regulating cuproptosis is becoming a rising cancer treatment modality. Here, we attempted to establish a cuproptosis-associated lncRNAs (CRLs) signature (CRlncSig) to predict the survival, immune landscape, and treatment response in ovarian cancer (OC) patients. Methods: A series of statistical analyses were used to identify the key CRLs that are closely related to the prognosis, and a prognostic CRlncSig was constructed. The predictive accuracy of the CRlncSig was further validated in an independent Gene Expression Omnibus (GEO) set. Then, we compared the immune cell infiltration, immune checkpoints, tumor microenvironment (TME), tumor mutational burden (TMB), drug sensitivity, and efficacy of immunotherapy between the two subgroups. We further built a nomogram integrating the CRlncSig and different clinical traits to enhance the clinical application of the CRlncSig. Results: Nine hub CRLs, namely RGMB-AS1, TYMSOS, DANCR, LINC00702, LINC00240, LINC00996, DNM1P35, LINC00892, and TMEM254-AS1, were correlated with the overall survival (OS) of OC and a prognostic CRlncSig was established. The CRlncSig classified OC patients into two risk groups with strikingly different survival probabilities. The time-dependent ROC (tdROC) curves demonstrated good predictive ability in both the training cohort and an independent validation cohort. Multivariate analysis confirmed the independent predictive performance of the CRlncSig. We constructed a nomogram based on the CRlncSig, which can predict the prognosis of OC patients. The high-risk score was characterized by decreased immune cell infiltration and activation of stroma, while activation of immunity was observed in the low-risk subgroup. Moreover, patients in low-risk subgroups had more Immunophenoscore (IPS) and fewer immune escapes compared to high-risk subgroups. Finally, an immunotherapeutic cohort confirmed the value of the CRlncSig in predicting immunotherapy outcomes. Conclusions: The developed CRlncSig may be promising for the clinical prediction of OC patient outcomes and immunotherapeutic responses.

Identification of Cuproptosis-Related Genes for Molecular Subtyping: Predicting Prognostic and Therapeutic Response in Glioma

Background

Cuproptosis, a metal-ion-dependent form of regulated cell death induced by copper overload, is emerging as a potential mechanism in high-grade glioma (HGG). Despite its significance, the role of cuproptosis in predicting the prognostic and therapeutic response in HGG remains poorly understood.

Methods

We performed unsupervised clustering to stratify patients with HGG in the Chinese Glioma Genome Atlas (CGGA) according to the expression of 14 cuproptosis-related genes (CRGs) and validated in The Cancer Genome Atlas (TCGA). Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were applied to explore the biological processes and pathways involved within distinct groups. We constructed the CupScore model to predict the responsiveness to immune checkpoint inhibitors (ICIs) therapy and chemotherapy in patients with HGG. Additionally, in vivo and in vitro experiments were performed to investigate the potential biological function of CDKN2A in HGG.

Results

We identified two cuproptosis-related molecular subgroups with significantly different survival probabilities. Patients with HGG in cluster 1 were characterized as immune-desert phenotype with higher CupScore and lower expression of MHC complex, interferons, chemokines, interleukins, and immune checkpoints. In contrast, cluster 2 showed an immune-inflamed signature. We screened PI-103 as the most promising candidate for patients with higher CupScore and confirmed its experimental evidence and clinical trial status. Patients with lower CupScore showed higher response rates to anti-PD-L1 and anti-PD1 combined with anti-CTLA4 ICI therapy. Furthermore, in vivo and in vitro experiments revealed that CDKN2A enhanced the malignant phenotype of HGG.

Conclusion

Cuproptosis has the ability to reprogram the tumor microenvironment (TME) in HGG, leading to the stratification of patients into two distinct molecular subgroups. The CupScore model emerged as a robust metric for predicting the prognostic and therapeutic benefits, as well as may therefore facilitate personalized treatment strategies for patients with HGG.

Cuproptosis, ferroptosis and PANoptosis in tumor immune microenvironment remodeling and immunotherapy: culprits or new hope

Normal life requires cell division to produce new cells, but cell death is necessary to maintain balance. Dysregulation of cell death can lead to the survival and proliferation of abnormal cells, promoting tumor development. Unlike apoptosis, necrosis, and autophagy, the newly recognized forms of regulated cell death (RCD) cuproptosis, ferroptosis, and PANoptosis provide novel therapeutic strategies for tumor treatment. Increasing research indicates that the death of tumor and immune cells mediated by these newly discovered forms of cell death can regulate the tumor microenvironment (TME) and influence the effectiveness of tumor immunotherapy. This review primarily elucidates the molecular mechanisms of cuproptosis, ferroptosis, and PANoptosis and their complex effects on tumor cells and the TME. This review also summarizes the exploration of nanoparticle applications in tumor therapy based on in vivo and in vitro evidence derived from the induction or inhibition of these new RCD pathways.

Delivery of SiRNA-PD-L1 by attenuated Salmonella in combination with oxaliplatin in a hepatocellular carcinoma mouse model

Oxaliplatin is currently used for chemotherapy in patients with hepatocellular carcinoma, but its increasing tolerance to tumours over time limits its clinical application. Studies have shown that high PD-L1 expression promotes the polarization of M2 macrophages. The increased infiltration of M2 macrophages, including those in HCC, is positively correlated with poor prognosis in various solid tumours. We found that oxaliplatin promoted the expression of PD-L1 in liver cancer cells, which might be attributed partly to the tolerance of tumours to oxaliplatin. Therefore, in this study, we explored the antitumour effect of attenuated Salmonella carrying siRNA-PD-L1 combined with oxaliplatin via Western blotting, immunohistochemistry, immunofluorescence, and flow cytometry. The results revealed that attenuated Salmonella carrying siRNA-PD-L1 combined with oxaliplatin more significantly inhibited tumour growth in tumour-bearing mice, suppressed the expression of PD-L1 in tumour tissue, increased the apoptosis of tumour cells and the expression of the tumour-related protein cleaved-caspase3, and increased the infiltration of M1 macrophages and T lymphocytes in tumour tissues. Moreover, the combination therapy increased the activation of T cells and the number of T lymphocytes and NK cells in the spleens of the mice and improved the overall antitumour immune response in the mice. Our results confirmed that attenuated Salmonella harbouring siRNA-PD-L1 combined with oxaliplatin had a significant antitumour effect and did not increase the incidence of toxic side effects, providing a theoretical reference for addressing oxaliplatin tolerance in the treatment of hepatocellular carcinoma.

Cuproptosis and Cuproptosis-Based Synergistic Therapy for Cancer Treatment

Copper, as an essential trace nutrient for human, plays a crucial role in numerous cellular activities, and is vital for maintaining homeostasis in organisms. Deviations from normal intracellular copper concentration range can disrupt the cellular homeostasis and lead to cell death. Cell death is the process in which cells lose their vitality and cannot sustain normal metabolism, which has various forms. The recently discovered cuproptosis mechanism differs from the previously recognized forms, which is triggered by intracellular copper accumulation. The discovery of cuproptosis has sparked interest among researchers, and this mechanism has been applied in the treatment of various intractable diseases, including different types of cancer. However, the developed cuproptosis-based therapies have revealed certain limitations, such as low immunostimulatory efficiency, poor tumor targeting, and inhibition by the tumor microenvironment. Therefore, researchers are devoted to combining cuproptosis with existing cancer therapies to develop more effective synergistic cancer therapies. This review summarizes the latest research advancements in the cuproptosis-based therapies for various types of cancer, with a focus on the synergistic cancer therapies. Finally, it provides an outlook on the future development of cuproptosis in anti-tumor therapy.

Construction of a Wilms tumor risk model based on machine learning and identification of cuproptosis-related clusters

BACKGROUND

Cuproptosis, a recently identified type of programmed cell death triggered by copper, has mechanisms in Wilms tumor (WT) that are not yet fully understood. This research focuses on examining the link between WT and Cuproptosis-related genes (CRGs), with the goal of developing a predictive model for WT.

METHODS

Four gene expression datasets related to WT were sourced from the GEO database. Subsequently, expression profiles of CRGs were extracted for differential analysis and immune infiltration studies. Utilizing 105 WT samples, clusters related to Cuproptosis were identified. This involved analyzing associated immune cell infiltration and conducting functional enrichment analysis. Disease-characteristic genes were pinpointed using weighted gene co-expression network analysis. Finally, the WT risk prediction model was constructed by four machine learning methods: random forest, support vector machine (SVM), generalized linear and extreme gradient strength model. The best-performing machine learning model was chosen, and a nomogram was created. The effectiveness of this predictive model was validated using methods such as the calibration curve, decision curve analysis, and by appiying it to the TARGET-GTEx dataset.

RESULTS

Thirteen differentially expressed Cuproptosis-related genes were identified. The infiltration level of CD8 + T cells in WT children was lower than that in Normal tissue (NT) children, and the level of M0 infiltration of macrophages and T follicular helper cells was higher than that in NT children. In addition, two clusters of cuproptosis-related WT were identified. Enrichment analysis results indicated that genes in cluster 2 were primarily involved in cell division, nuclear division regulation, DNA biosynthesis process, ubiquitin-mediated proteolysis. The SVM model was judged to be the optimal model using 5 genes. Its accuracy was confirmed through a calibration curve and decision curve analysis, demonstrating satisfactory performance on the TARGET-GTEx validation dataset. Additional analysis revealed that these five genes exhibited high expression in both the TARGET-GTEx validation dataset and sequencing data.

CONCLUSION

This research established a link between WT and Cuproptosis. It developed a predictive model for assessing the risk of WT and pinpointed five key genes associated with the disease.

Dysregulated Wnt/β-catenin signaling confers resistance to cuproptosis in cancer cells

Cuproptosis is characterized by the aggregation of lipoylated enzymes of the tricarboxylic acid cycle and subsequent loss of iron-sulfur cluster proteins as a unique copper-dependent form of regulated cell death. As dysregulation of copper homeostasis can induce cuproptosis, there is emerging interest in exploiting cuproptosis for cancer therapy. However, the molecular drivers of cancer cell evasion of cuproptosis were previously undefined. Here, we found that cuproptosis activates the Wnt/β-catenin pathway. Mechanistically, copper binds PDK1 and promotes its interaction with AKT, resulting in activation of the Wnt/β-catenin pathway and cancer stem cell (CSC) properties. Notably, aberrant activation of Wnt/β-catenin signaling conferred resistance of CSCs to cuproptosis. Further studies showed the β-catenin/TCF4 transcriptional complex directly binds the ATP7B promoter, inducing its expression. ATP7B effluxes copper ions, reducing intracellular copper and inhibiting cuproptosis. Knockdown of TCF4 or pharmacological Wnt/β-catenin blockade increased the sensitivity of CSCs to elesclomol-Cu-induced cuproptosis. These findings reveal a link between copper homeostasis regulated by the Wnt/β-catenin pathway and cuproptosis sensitivity, and suggest a precision medicine strategy for cancer treatment through selective cuproptosis induction.

Unveiling Cuproptosis: Mechanistic insights, roles, and leading advances in oncology

Copper, a vital micronutrient, performs essential functions in numerous biological settings. Its disrupted metabolism is implicated in both the initiation of tumors and therapeutic interventions for cancer, underscoring the critical necessity of preserving copper homeostasis. Cuproptosis, a regulated cell death (RCD) modulated by copper, is activated in response to elevated copper concentrations, prompting an investigation into its implication in oncogenesis. Within this review, an exploration is conducted into copper dynamics and homeostasis maintenance within cells. Furthermore, it delves into the mechanisms underlying cuproptosis and its interplay with signaling pathways implicated in cancer. The potential synergy between cuproptosis and ferroptosis and its impact on tumor immunomodulation is discussed. Additionally, promising avenues for addressing cuproptosis in cancer involve assessing the utility of copper chelators and ionophores. By addressing pressing questions surrounding cuproptosis and outlining its pivotal role in cancer pathogenesis and treatment, this review propounds targeting cuproptosis as a promising frontier in antitumor therapy, potentially revolutionizing cancer treatment strategies.

Copper homeostasis and copper-induced cell death in tumor immunity: implications for therapeutic strategies in cancer immunotherapy

Copper is an important trace element for maintaining key biological functions such as cellular respiration, nerve conduction, and antioxidant defense. Maintaining copper homeostasis is critical for human health, and its imbalance has been linked to various diseases, especially cancer. Cuproptosis, a novel mechanism of copper-induced cell death, provides new therapeutic opportunities for metal ion regulation to interact with cell fate. This review provides insights into the complex mechanisms of copper metabolism, the molecular basis of cuproptosis, and its association with cancer development. We assess the role of cuproptosis-related genes (CRGs) associated with tumorigenesis, their importance as prognostic indicators and therapeutic targets, and the impact of copper homeostasis on the tumor microenvironment (TME) and immune response. Ultimately, this review highlights the complex interplay between copper, cuproptosis, and cancer immunotherapy.

The role of cuproptosis in gastric cancer

As a biologically essential transition metal, copper is widely involved in various enzymatic reactions and crucial biological processes in the body. It plays an increasingly important role in maintaining normal cellular metabolism and supporting the growth and development of the human body. As a trace element, copper maintains the dynamic balance of its concentration in body fluids through active homeostatic mechanisms. Both excess and deficiency of copper ions can impair cell function, ultimately leading to cell damage and death. Cuproptosis is a novel form of cell death where copper ions cause cell death by directly binding to the lipoylated components of the citric acid cycle (CAC) in mitochondrial respiration and interfering with the levels of iron-sulfur cluster (Fe-S cluster) proteins, ultimately causing protein toxic stress. Its primary characteristics are Cu2+ concentration dependence and high expression in mitochondrial respiratory cells. Recent research has revealed that, compared to other forms of programmed cell death such as apoptosis, necrosis, and autophagy, cuproptosis has unique morphological and biochemical features. Cuproptosis is associated with the occurrence and development of various diseases, including cancer, neurodegenerative diseases, and cardiovascular diseases. This article focuses on a review of the relevance of cuproptosis in gastric cancer (GC).

Copper-Based Nanomedicines for Cuproptosis-Mediated Effective Cancer Treatment

The recent discovery of cuproptosis, a novel copper-ion-induced cell death pathway, has suggested the novel therapeutic potential for treating heterogeneous and drug-resistant cancers. Currently, copper ionophore-based therapeutics have been designed to treat cancers, utilizing copper ions as a strategic tool to impede tumor proliferation and promote cellular demise. However, limitations of copper ionophore-based therapies include nontargeted delivery of copper ions, low tumor accumulation, and short half-life. Strategies to enhance specificity involve targeting intracellular cuproptosis mechanisms using nanotechnology-based drugs. Additionally, the importance of exploring combination therapies cannot be overstated, as they are a key strategy in improving the efficacy of cancer treatments. Recent studies have reported the anticancer effects of nanomedicines that can induce cuproptosis of cancer both in vitro and in vivo. These cuproptosis-targeted nanomedicines could improve delivery efficiency with the pharmacokinetic properties of copper ion, resulting in increasing cuproptosis-based anticancer effects. This review will summarize the intricate nexus between copper ion and carcinogenesis, examining the pivotal roles of copper homeostasis and its dysregulation in cancer progression and fatality. Furthermore, we will introduce the latest advances in cuproptosis-targeted nanomedicines for cancer treatment. Finally, the challenges in cuproptosis-based nanomedicines will be discussed for future development directions.

A spotlight on the role of copper in the epithelial to mesenchymal transition

The complex process known as epithelial to mesenchymal transition (EMT) plays a fundamental role in several biological settings, encompassing embryonic development, wound healing, and pathological conditions such as cancer and fibrosis. In recent years, a bulk of research has brought to light the key role of copper, a trace element with essential functions in cellular metabolism, cancer initiation and progression. Indeed, copper, besides functioning as cofactor of enzymes required for essential cellular processes, such as energy production and oxidation reactions, has emerged as an allosteric regulator of kinases whose activity is required to fulfill cancer dissemination through the EMT. In this comprehensive review, we try to describe the intricate relationship between the transition metal copper and EMT, spanning from the earliest foundational studies to the latest advancements. Our aim is to shed light on the multifaceted roles undertaken by copper in EMT in cancer and to unveil the diverse mechanisms by which copper homeostasis exerts its influence over EMT regulators, signaling pathways, cell metabolic reprogramming and transcription factors ultimately contributing to the spread of cancer. Therefore, this review not only may contribute to a deeper comprehension of copper-mediated mechanisms in EMT but also supports the hypothesis that targeting copper may contribute to counteract the progression of EMT-associated pathologies.

A novel network-based method identifies a cuproplasia-related pan-cancer gene signature to predict patient outcome

Copper is a vital micronutrient involved in many biological processes and is an essential component of tumour cell growth and migration. Copper influences tumour growth through a process called cuproplasia, defined as abnormal copper-dependent cell-growth and proliferation. Copper-chelation therapy targeting this process has demonstrated efficacy in several clinical trials against cancer. While the molecular pathways associated with cuproplasia are partially known, genetic heterogeneity across different cancer types has limited the understanding of how cuproplasia impacts patient survival. Utilising RNA-sequencing data from The Cancer Genome Atlas (TCGA) and the Genotype-Tissue Expression (GTEx) datasets, we generated gene regulatory networks to identify the critical cuproplasia-related genes across 23 different cancer types. From this, we identified a novel 8-gene cuproplasia-related gene signature associated with pan-cancer survival, and a 6-gene prognostic risk score model in low grade glioma. These findings highlight the use of gene regulatory networks to identify cuproplasia-related gene signatures that could be used to generate risk score models. This can potentially identify patients who could benefit from copper-chelation therapy and identifies novel targeted therapeutic strategies.

Pan-cancer analysis reveals copper transporters as promising potential targets

Background

Copper transport proteins (SLC31A1, ATP7A, ATP7B) regulate copper levels in the body and may be involved in tumor development. However, their comprehensive expression and function across various cancers remain unclear.

Methods

The expressions of copper transporters in 33 tumors and normal tissues were analyzed using TCGA, GTEx, CCLE, ULCAN, and HPA databases. Cox regression assessed their impact on patient survival. Gene alterations were explored using cBioPortal. Spearman correlation tests were performed to investigate the associations between copper transporters and tumor mutation burden (TMB), microsatellite instability (MSI), and infiltration of immune cells. Gene functions were analyzed using STRING and GeneMANIA databases. Drug sensitivity was assessed using GSCALite database. ATP7B expression in lung squamous cell carcinoma (LUSC) was validated by immunohistochemical staining.

Results

Copper transporters exhibited variable expression patterns across various cancer types, indicating their potential dual role as either oncogenes or tumor suppressor genes, depending on the cancer type. Significant associations were found between these transporters and tumor stage, as well as prognosis in most tumors studied. Pathway analysis identified links between copper transporters and tumor-related pathways like apoptosis and RAS/MAPK. Copy number variation (CNV) analysis revealed varying degrees of gene amplification and deletion of copper transporters in most tumors. Copper transporters exhibited strong correlations with immune features, including TMB, MSI, and immune-infiltrating cells, suggesting their potential role in guiding immunotherapy. They were also associated with sensitivity to various chemotherapeutic and immunotherapeutic drugs. Immunohistochemical tests validated the correlation between elevated ATP7B level and worse progression-free survival (PFS) in LUSC.

Conclusion

Copper transporters may serve as potential tumor markers and therapeutic targets.

Copper metabolism in osteoarthritis and its relation to oxidative stress and ferroptosis in chondrocytes

Ferroptosis, an iron-ion-dependent process of lipid peroxidation, damages the plasma membrane, leading to non-programmed cell death. Osteoarthritis (OA), a prevalent chronic degenerative joint disease among middle-aged and older adults, is characterized by chondrocyte damage or loss. Emerging evidence indicates that chondrocyte ferroptosis plays a role in OA development. However, most research has concentrated on ferroptosis regulation involving typical iron ions, potentially neglecting the significance of elevated copper ions in both serum and joint fluid of patients with OA. This review aims to fill this gap by systematically examining the interplay between copper metabolism, oxidative stress, ferroptosis, and copper-associated cell death in OA. It will provide a comprehensive overview of copper ions' role in regulating ferroptosis and their dual role in OA. This approach seeks to offer new insights for further research, prevention, and treatment of OA.

Alterations in Astrocyte Subpopulations in Glioma and Identification of Cuproptosis-Related Genes Using Single-Cell RNA Sequencing

Purpose

Mitochondrial metabolism is essential for energy production and the survival of brain cells, particularly in astrocytes. Cuproptosis is a newly identified form of programmed cell death that occurs due to the disruption of mitochondrial metabolism caused by excessive copper toxicity. However, the relationship between cuproptosis-related genes (CRGs) in the tumor microenvironment (TME) and the prognosis of gliomas remains unclear.

Patients and Methods

In this study, we utilized 32,293 cells obtained from three in-house single-cell RNA sequencing (scRNA-seq) datasets, along with 6,148 cells acquired from the Chinese Glioma Genome Atlas (CGGA) involving 14 glioma patients, to identify and validate the TME of gliomas.

Results

Based on an analysis of 32,293 single cells, we investigated intra-tumor heterogeneity, intercellular communication, and astrocyte differentiation trajectories in gliomas. Our findings revealed that the TGFβ signaling pathway exhibited a higher relative strength in astrocyte subpopulations. Additionally, we identified a novel three-gene signature (CDKN2A, SOX2, and MPC1) was identified for prognostic prediction. Furthermore, glioma patients with a high-risk score demonstrated poorer overall survival (OS) compared to those with a low-risk score in both training and testing datasets (P training set < 0.001; P test set = 0.037).

Conclusion

Our study revealed the prognostic value of the CRGs in astrocytes exhibiting tumor immunosuppressive characteristics in glioma. We established a novel three-gene prognostic model that offers new insights into the prognosis and treatment strategies for gliomas.

Cell Death: Mechanisms and Potential Targets in Breast Cancer Therapy

Breast cancer (BC) has become the most life-threatening cancer to women worldwide, with multiple subtypes, poor prognosis, and rising mortality. The molecular heterogeneity of BC limits the efficacy and represents challenges for existing therapies, mainly due to the unpredictable clinical response, the reason for which probably lies in the interactions and alterations of diverse cell death pathways. However, most studies and drugs have focused on a single type of cell death, while the therapeutic opportunities related to other cell death pathways are often neglected. Therefore, it is critical to identify the predominant type of cell death, the transition to different cell death patterns during treatment, and the underlying regulatory mechanisms in BC. In this review, we summarize the characteristics of various forms of cell death, including PANoptosis (pyroptosis, apoptosis, necroptosis), autophagy, ferroptosis, and cuproptosis, and discuss their triggers and signaling cascades in BC, which may provide a reference for future pathogenesis research and allow for the development of novel targeted therapeutics in BC.