Proteomics revealed the crosstalk between copper stress and cuproptosis, and explored the feasibility of curcumin as anticancer copper ionophore

Ferroptosis and cuproptosis: Metal-dependent cell death pathways activated in response to classical chemotherapy - Significance for cancer treatment?

Apoptosis has traditionally been regarded as the desired cell death pathway activated by chemotherapeutic drugs due to its controlled and non-inflammatory nature. However, recent discoveries of alternative cell death pathways have paved the way for immune-stimulatory treatment approaches in cancer. Ferroptosis (dependent on iron) and cuproptosis (dependent on copper) hold promise for selective cancer cell targeting and overcoming drug resistance. Copper ionophores and iron-bearing nano-drugs show potential for clinical therapy as single agents and as adjuvant treatments. Here we review up-to-date evidence for the involvement of metal ion-dependent cell death pathways in the cytotoxicity of classical chemotherapeutic agents (alkylating agents, topoisomerase inhibitors, antimetabolites, and mitotic spindle inhibitors) and their combinations with cuproptosis and ferroptosis inducers, indicating the prospects, advantages, and obstacles of their use.

Thiosemicarbazone Mixed-Valence Cu(I/II) Complex against Lung Adenocarcinoma Cells through Multiple Pathways Involving Cuproptosis

Induction of cuproptosis and targeting of multiple signaling pathways show promising applications in tumor therapy. In this study, we synthesized two thiosemicarbazone-copper complexes ([CuII(L)Cl] 1 and [CuII2CuI(L)2Cl3] 2, where HL is the (E)-N-methyl-2-(phenyl(pyridin-2-yl)methylene ligand), to assess their antilung cancer activities. Both copper complexes showed better anticancer activity than cisplatin and exhibited hemolysis comparable to that of cisplatin. In vivo experiments showed that complex 2 retarded the A549 cell growth in a mouse xenograft model with low systemic toxicity. Primarily, complex 2 kills lung cancer cells in vitro and in vivo by triggering multiple pathways, including cuproptosis. Complex 2 is the first mixed-valent Cu(I/II) complex to induce cellular events consistent with cuproptosis in cancer cells, which may stimulate the development of mixed-valent copper complexes and provide effective cancer therapy.

Copper homeostasis in chronic kidney disease and its crosstalk with ferroptosis

Chronic kidney disease (CKD) has become a global public health problem with high morbidity and mortality. Renal fibrosis can lead to end-stage renal disease (ESRD). However, there is still no effective treatment to prevent or delay the progression of CKD into ESRD. Therefore, exploring the pathogenesis of CKD is essential for preventing and treating CKD. There are a variety of trace elements in the human body that interact with each other within a complex regulatory network. Iron and copper are both vital trace elements in the body. They are critical for maintaining bodily functions, and the dysregulation of their metabolism can cause many diseases, including kidney disease. Ferroptosis is a new form of cell death characterized by iron accumulation and lipid peroxidation. Studies have shown that ferroptosis is closely related to kidney disease. However, the role of abnormal copper metabolism in kidney disease and its relationship with ferroptosis remains unclear. Here, our current knowledge regarding copper metabolism, its regulatory mechanism, and the role of abnormal copper metabolism in kidney diseases is summarized. In addition, we discuss the relationship between abnormal copper metabolism and ferroptosis to explore the possible pathogenesis and provide a potential therapeutic target for CKD.

The effect of lipid metabolism on cuproptosis-inducing cancer therapy

Cuproptosis provides a new therapeutic strategy for cancer treatment and is thought to have broad clinical application prospects. Nevertheless, some oncological clinical trials have yet to demonstrate favorable outcomes, highlighting the need for further research into the molecular mechanisms underlying cuproptosis in tumors. Cuproptosis primarily hinges on the intracellular accumulation of copper, with lipid metabolism exerting a profound influence on its course. The interaction between copper metabolism and lipid metabolism is closely related to cuproptosis. Copper imbalance can affect mitochondrial respiration and lipid metabolism changes, while lipid accumulation can promote copper uptake and absorption, and inhibit cuproptosis induced by copper. Anomalies in lipid metabolism can disrupt copper homeostasis within cells, potentially triggering cuproptosis. The interaction between cuproptosis and lipid metabolism regulates the occurrence, development, metastasis, chemotherapy drug resistance, and tumor immunity of cancer. Cuproptosis is a promising new target for cancer treatment. However, the influence of lipid metabolism and other factors should be taken into consideration. This review provides a brief overview of the characteristics of the interaction between cuproptosis and lipid metabolism in cancer and analyses potential strategies of applying cuproptosis for cancer treatment.

Photochemically Controlled Release of the Glucose Transporter 1 Inhibitor for Glucose Deprivation Responses and Cancer Suppression Research

Cancer cells need a greater supply of glucose mainly due to their aerobic glycolysis, known as the Warburg effect. Glucose transport by glucose transporter 1 (GLUT1) is the rate-limiting step for glucose uptake, making it a potential cancer therapeutic target. However, GLUT1 is widely expressed and performs crucial functions in a variety of cells, and its indiscriminate inhibition will cause serious side effects. In this study, we designed and synthesized a photocaged GLUT1 inhibitor WZB117-PPG to suppress the growth of cancer cells in a spatiotemporally controllable manner. WZB117-PPG exhibited remarkable photolysis efficiency and substantial cytotoxicity toward cancer cells under visible light illumination with minimal side effects, ensuring its safety as a potential cancer therapy. Furthermore, our quantitative proteomics data delineated a comprehensive portrait of responses in cancer cells under glucose deprivation, underlining the mechanism of cell death via necrosis rather than apoptosis. We reason that our study provides a potentially reliable cancer treatment strategy and can be used as a spatiotemporally controllable trigger for studying nutrient deprivation-related stress responses.

Crosstalk between ferroptosis and cuproptosis: From mechanism to potential clinical application

Ferroptosis and cuproptosis, regulated forms of cell death resulting from metal ion accumulation, are closely related in terms of occurrence, cell metabolism, signaling pathways, and drug resistance. Notably, it is now understood that these processes play crucial roles in regulating physiological and pathological processes, especially in tumor development. Consequently, ferroptosis and cuproptosis have gained increasing significance as potential targets for anti-cancer drug development. This article systematically outlines the molecular mechanisms and cross-talk components of both ferroptosis and cuproptosis, elucidating their impacts on cancer. Furthermore, it investigates the clinical perspective of targeted ferroptosis and cuproptosis in cancer chemotherapy, immunotherapy, and radiotherapy. Our discussion extends to a comparative analysis of nanoparticles developed based on the mechanisms of ferroptosis and cuproptosis in cancer, contrasting them with current conventional therapies. Opportunities and challenges in cancer treatment are explored, emphasizing the potential therapeutic direction of co-targeting ferroptosis and cuproptosis. The article also attempts to analyze the clinical applications of this co-targeting approach for cancer treatment while summarizing the existing barriers that require overcoming.

Copper homeostasis and cuproptosis in cancer immunity and therapy

Copper is an essential nutrient for maintaining enzyme activity and transcription factor function. Excess copper results in the aggregation of lipoylated dihydrolipoamide S-acetyltransferase (DLAT), which correlates to the mitochondrial tricarboxylic acid (TCA) cycle, resulting in proteotoxic stress and eliciting a novel cell death modality: cuproptosis. Cuproptosis exerts an indispensable role in cancer progression, which is considered a promising strategy for cancer therapy. Cancer immunotherapy has gained extensive attention owing to breakthroughs in immune checkpoint blockade; furthermore, cuproptosis is strongly connected to the modulation of antitumor immunity. Thus, a thorough recognition concerning the mechanisms involved in the modulation of copper metabolism and cuproptosis may facilitate improvement in cancer management. This review outlines the cellular and molecular mechanisms and characteristics of cuproptosis and the links of the novel regulated cell death modality with human cancers. We also review the current knowledge on the complex effects of cuproptosis on antitumor immunity and immune response. Furthermore, potential agents that elicit cuproptosis pathways are summarized. Lastly, we discuss the influence of cuproptosis induction on the tumor microenvironment as well as the challenges of adding cuproptosis regulators to therapeutic strategies beyond traditional therapy.

Copper in Gynecological Diseases

Copper (Cu) is an essential micronutrient for the correct development of eukaryotic organisms. This metal plays a key role in many cellular and physiological activities, including enzymatic activity, oxygen transport, and cell signaling. Although the redox activity of Cu is crucial for enzymatic reactions, this property also makes it potentially toxic when found at high levels. Due to this dual action of Cu, highly regulated mechanisms are necessary to prevent both the deficiency and the accumulation of this metal since its dyshomeostasis may favor the development of multiple diseases, such as Menkes' and Wilson's diseases, neurodegenerative diseases, diabetes mellitus, and cancer. As the relationship between Cu and cancer has been the most studied, we analyze how this metal can affect three fundamental processes for tumor progression: cell proliferation, angiogenesis, and metastasis. Gynecological diseases are characterized by high prevalence, morbidity, and mortality, depending on the case, and mainly include benign and malignant tumors. The cellular processes that promote their progression are affected by Cu, and the mechanisms that occur may be similar. We analyze the crosstalk between Cu deregulation and gynecological diseases, focusing on therapeutic strategies derived from this metal.

Integrated bioinformatics and experiment revealed that cuproptosis is the potential common pathogenesis of three kinds of primary cardiomyopathy

Cuproptosis is a recently reported new mode of programmed cell death which might be a potential co-pathogenesis of three kinds of primary cardiomyopathy. However, no investigation has reported a clear relevance between primary cardiomyopathy and cuproptosis. In this study, the differential cuproptosis-related genes (CRGs) shared by three kinds of primary cardiomyopathy were identified in training sets. As a result, four CRGs shared by three kinds of primary cardiomyopathy were acquired and they were mainly related to biological processes such as cell death and immuno-inflammatory response through differential analysis, correlation analysis, GSEA, GSVA and immune cell infiltration analysis. Then, three key CRGs (K-CRGs) with high diagnostic value were identified by LASSO regression. The results of nomogram, machine learning, ROC analysis, calibration curve and decision curve indicated that the K-CRGs exhibited outstanding performance in the diagnosis of three kinds of primary cardiomyopathy. After that, in each disease, two molecular subtypes clusters were distinguished. There were many differences between different clusters in the biological processes associated with cell death and immunoinflammation and K-CRGs had excellent molecular subtype identification efficacy. Eventually, results from validation datasets and in vitro experiments verified the role of K-CRGs in diagnosis of primary cardiomyopathy, identification of primary cardiomyopathic molecular subtypes and pathogenesis of cuproptosis. In conclusion, this study found that cuproptosis might be the potential common pathogenesis of three kinds of primary cardiomyopathy and K-CRGs might be promising biomarkers for the diagnosis and molecular subtypes identification of primary cardiomyopathy.

Iron and copper: critical executioners of ferroptosis, cuproptosis and other forms of cell death

Regulated cell death (RCD) is a regulable cell death that involves well-organized signaling cascades and molecular mechanisms. RCD is implicated in fundamental processes such as organ production and tissue remodeling, removing superfluous structures or cells, and regulating cell numbers. Previous studies have not been able to reveal the complete mechanisms, and novel methods of RCD are constantly being proposed. Two metal ions, iron (Fe) and copper (Cu) are essential factors leading to RCDs that not only induce ferroptosis and cuproptosis, respectively but also lead to cell impairment and eventually diverse cell death. This review summarizes the direct and indirect mechanisms by which Fe and Cu impede cell growth and the various forms of RCD mediated by these two metals. Moreover, we aimed to delineate the interrelationships between these RCDs with the distinct pathways of ferroptosis and cuproptosis, shedding light on the complex and intricate mechanisms that govern cellular survival and death. Finally, the prospects outlined in this review suggest a novel approach for investigating cell death, which may involve integrating current therapeutic strategies and offer a promising solution to overcome drug resistance in certain diseases. Video Abstract.

Identification of disulfidptosis-related subtypes, characterization of tumor microenvironment infiltration, and development of a prognosis model in colorectal cancer

BACKGROUND

Colorectal cancer is the second leading cause of cancer-related deaths, which imposes a significant societal burden. Regular screening and emerging molecular tumor markers have important implications for detecting the progression and development of colorectal cancer. Disulfidptosis is a newly defined type of programmed cell death triggered by abnormal accumulation of disulfide compounds in cells that stimulate disulfide stress. Currently, there is no relevant discussion on this mechanism and colorectal cancer.

METHODS

We classified the disulfidptosis-related subtypes of colorectal cancer using bioinformatics methods. Through secondary clustering of differentially expressed genes between subtypes, we identified characteristic genes of the disulfidptosis subtype, constructed a prognostic model, and searched for potential biomarkers through clinical validation.

RESULTS

Using disulfidptosis-related genes collected from the literature, we classified colorectal cancer patients from public databases into three subtypes. The differentially expressed genes between subtypes were clustered into three gene subtypes, and eight characteristic genes were screened to construct a prognostic model.

CONCLUSION

The disulfidptosis mechanism has important value in the classification of colorectal cancer patients, and characteristic genes selected based on this mechanism can serve as a new potential biological marker for colorectal cancer.

Cuproptosis and cuproptosis-related genes: Emerging potential therapeutic targets in breast cancer

Breast cancer is one of the most common malignant tumors in women worldwide, and thus, it is important to enhance its treatment efficacy [1]. Copper has emerged as a critical trace element that affects various intracellular signaling pathways, gene expression, and biological metabolic processes [2], thereby playing a crucial role in the pathogenesis of breast cancer. Recent studies have identified cuproptosis, a newly discovered type of cell death, as an emerging therapeutic target for breast cancer treatment, thereby offering new hope for breast cancer patients. Tsvetkov's research has elucidated the mechanism of cuproptosis and uncovered the critical genes involved in its regulation [3]. Manipulating the expression of these genes could potentially serve as a promising therapeutic strategy for breast cancer treatment. Additionally, using copper ionophores and copper complexes combined with nanomaterials to induce cuproptosis may provide a potential approach to eliminating drug-resistant breast cancer cells, thus improving the therapeutic efficacy of chemotherapy, radiotherapy, and immunotherapy and eventually eradicating breast tumors. This review aims to highlight the practical significance of cuproptosis-related genes and the induction of cuproptosis in the clinical diagnosis and treatment of breast cancer. We examine the potential of cuproptosis as a novel therapeutic target for breast cancer, and we explore the present challenges and limitations of this approach. Our objective is to provide innovative ideas and references for the development of breast cancer treatment strategies based on cuproptosis.

Evaluation the role of cuproptosis-related genes in the pathogenesis, diagnosis and molecular subtypes identification of atherosclerosis

Background

At present, the pathogenesis of atherosclerosis has not been fully elucidated, and the diagnosis and treatment face great challenges. Cuproptosis is a novel cell death pattern that might be involved in the development of atherosclerosis. However, no research has reported the correlation between cuproptosis and atherosclerosis.

Methods

The differential cuproptosis-related genes (CRGs) between atherosclerosis group and control group (A-CRGs) were discovered via differential expression analysis. The correlation analysis, PPI network analysis, GO, KEGG and GSEA analysis were performed to investigate the function of A-CRGs. The differences of biological function between atherosclerosis group and control group were investigated via immune infiltration analysis and GSVA. The LASSO regression, nomogram and machine learning models were constructed to predict atherosclerosis risk. The atherosclerosis molecular subtypes clusters were discovered via unsupervised cluster analysis. Subsequently, we used the above research methods to analyze the differential CRGs between clusters (M-CRGs) and evaluate the molecular subtypes identification performance of M-CRGs. Finally, we verified the diagnostic value for atherosclerosis and role in cuproptosis of these CRGs through the validation set and in vitro experiments.

Results

Five A-CRGs were identified and they were mainly related to the biological function of copper ion metabolism and immune inflammatory response. The diagnostic models and nomogram of atherosclerosis based on 5 A-CRGs indicated that these genes had well diagnostic value. A total of two molecular subtypes clusters were obtained in the atherosclerosis group. There were many differences in biological functions between these two molecular subtypes clusters, such as mitochondrial outer membrane permeabilization and primary immunodeficiency. In addition, 3 M-CRGs were identified in the 2 clusters. Machine learning models and nomogram constructed based on M-CRGs showed that these genes had well molecular subtypes identification efficacy. In the end, the results of in vitro experiment and validation set confirmed the diagnostic value for atherosclerosis and role in cuproptosis of these genes.

Conclusion

The cuproptosis may be a potential pathogenesis of atherosclerosis and CRGs may be promising markers for the diagnosis and molecular subtypes identification of atherosclerosis.

Polysiloxane-Based Molecular Logic Gate for Dual-Channel Visualizing Mitochondrial pH and Sulphite Changes during Cuproptosis

Intracellular Cu-induced regulated cell death, characterized by the aggregation of lipidizing mitochondrial enzymes, is called cuproptosis. Mitochondria play a vital role in the metabolic regulation of cell injury and stressful immune responses. The pH levels and sulfur dioxide (SO2) content in mitochondria have important indicative roles in the regulation of cuproptosis. However, fluorescent probes that simultaneously detect changes in pH and SO2 in mitochondria during cuprotosis have not been reported. To fill this blank, in this study, we dexterously used functional polysiloxane as a fluorescent platform to propose a molecular logic gate probe P0-pH-SO2 for detecting changes in intramitochondrial pH and SO2 content through a dual-channel mode. In addition, we defined a new function to reflect the cellular state of the elesclomol-induced cuproptosis process based on the input and output of the relevant logic relationship. This new fluorescent molecular logic gate probe P0-pH-SO2 can be rapidly activated by mitochondrial sulfites to induce green fluorescence, while the red fluorescence is quenched with the proton in the mitochondria. Overall, this study developed a novel logic-gated molecular probe that provided a versatile strategy for monitoring the role played by intramitochondrial sulfites and H+ in cuproptosis. This work will open the way to broaden the applications of molecular logic gates and fluorescent polysiloxanes.

Copper-instigated modulatory cell mortality mechanisms and progress in oncological treatment investigations

Copper, a transition metal, serves as an essential co-factor in numerous enzymatic active sites and constitutes a vital trace element in the human body, participating in crucial life-sustaining activities such as energy metabolism, antioxidation, coagulation, neurotransmitter synthesis, iron metabolism, and tetramer deposition. Maintaining the equilibrium of copper ions within biological systems is of paramount importance in the prevention of atherosclerosis and associated cardiovascular diseases. Copper induces cellular demise through diverse mechanisms, encompassing reactive oxygen species responses, apoptosis, necrosis, pyroptosis, and mitochondrial dysfunction. Recent research has identified and dubbed a novel regulatory cell death modality-"cuprotosis"-wherein copper ions bind to acylated proteins in the tricarboxylic acid cycle of mitochondrial respiration, resulting in protein aggregation, subsequent downregulation of iron-sulfur cluster protein expression, induction of proteotoxic stress, and eventual cell death. Scholars have synthesized copper complexes by combining copper ions with various ligands, exploring their significance and applications in cancer therapy. This review comprehensively examines the multiple pathways of copper metabolism, copper-induced regulatory cell death, and the current status of copper complexes in cancer treatment.

Curcumin suppresses cell proliferation and reduces cholesterol absorption in Caco-2 cells by activating the TRPA1 channel

BACKGROUND

Curcumin (Cur) is a bioactive dietary polyphenol of turmeric with various biological activities against several cancers. Colorectal cancer (CRC) is one of the leading causes of cancer-related deaths. Intestinal cholesterol homeostasis is associated with CRC. Chemotherapy for CRC is related to varied adverse effects. Therefore, natural products with anti-cancer properties represent a potential strategy for primary prevention of CRC.

METHODS

The present study used Cur as a therapeutic approach against CRC using the Caco-2 cell line. The cells were treated with different concentrations of Cur for different duration of time and then the proliferation ability of cells was assessed using Cell Counting Kit-8 and 5-Ethynyl-2'-deoxyuridine assays. Oil red O staining and cholesterol assay kit were used to evaluate cellular lipid content and cholesterol outward transportation. Finally, the protein expressions of cholesterol transport-related protein and signal transduction molecules were assessed using Western blot assay.

RESULTS

Cur inhibited cell proliferation in Caco-2 cells in a dose- and time-dependent manner by activating the transient receptor potential cation channel subfamily A member 1 (TRPA1) channel. Activation of the TRPA1 channel led to increased intracellular calcium, peroxisome proliferator-activated receptor gamma (PPARγ) upregulation, and the subsequent downregulation of the specificity protein-1 (SP-1)/sterol regulatory element-binding protein-2 (SREBP-2)/Niemann-Pick C1-like 1 (NPC1L1) signaling pathway-related proteins, and finally reduced cholesterol absorption in Caco-2 cells.

CONCLUSIONS

Cur inhibits cell proliferation and reduces cholesterol absorption in Caco-2 cells through the Ca²⁺/PPARγ/SP-1/SREBP-2/NPC1L1 signaling by activating the TRPA1 channel, suggesting that Cur can be used as a dietary supplement for the primary prevention of CRC. In Caco-2 cells, Cur first stimulates calcium influx by activating the TRPA1 channel, further upregulates PPARγ and downregulates SP-1/SREBP-2/NPC1L1 signaling pathway, and finally inhibits the absorption of cholesterol. TRPA1, transient receptor potential cation channel subfamily A member 1; NPC1L1, Niemann-Pick C1-like 1; PPARγ, peroxisome proliferator-activated receptor gamma; SP-1, specificity protein-1; SREBP-2, sterol regulatory element-binding protein-2; Cur, curcumin.