Copper improves the anti-angiogenic activity of disulfiram through the EGFR/Src/VEGF pathway in gliomas

EGFR amplification and EGFRvIII predict and participate in TAT-Cx43266-283 antitumor response in preclinical glioblastoma models

BACKGROUND

Glioblastoma (GBM) commonly displays epidermal growth factor receptor (EGFR) alterations (mainly amplification and EGFRvIII) and TAT-Cx43266-283 is a Src-inhibitory peptide with antitumor properties in preclinical GBM models. Given the link between EGFR and Src, the aim of this study was to explore the role of EGFR in the antitumor effects of TAT-Cx43266-283.

METHODS

The effect of TAT-Cx43266-283, temozolomide (TMZ), and erlotinib (EGFR inhibitor) was studied in patient-derived GBM stem cells (GSCs) and murine neural stem cells (NSCs) with and without EGFR alterations, in vitro and in vivo. EGFR alterations were analyzed by western blot and fluorescence in situ hybridization in these cells, and compared with Src activity and survival in GBM samples from The Cancer Genome Atlas.

RESULTS

The effect of TAT-Cx43266-283 correlated with EGFR alterations in a set of patient-derived GSCs and was stronger than that exerted by TMZ and erlotinib. In fact, TAT-Cx43266-283 only affected NSCs with EGFR alterations, but not healthy NSCs. EGFR alterations correlated with Src activity and poor survival in GBM patients. Finally, tumors generated from NSCs with EGFR alterations showed a decrease in growth, invasiveness, and vascularization after treatment with TAT-Cx43266-283, which enhanced the survival of immunocompetent mice.

CONCLUSIONS

Clinically relevant EGFR alterations are predictors of TAT-Cx43266-283 response and part of its mechanism of action, even in TMZ- and erlotinib-resistant GSCs. TAT-Cx43266-283 targets NSCs with GBM-driver mutations, including EGFR alterations, in an immunocompetent GBM model in vivo, suggesting a promising effect on GBM recurrence. Together, this study represents an important step toward the clinical application of TAT-Cx43266-283.

Cuproptosis in cancers: Function and implications from bench to bedside

Copper, an indispensable micronutrient, is implicated in numerous vital biological processes and is essential for all physiological activities. Recently, the discovery of a novel type of copper-dependent cell death, known as cuproptosis, has shed light on its role in cancer development. Extensive research is currently underway to unravel the mechanisms underlying cuproptosis and its correlation with various cancer types. In this review, we summarize the findings regarding the roles and mechanisms of cuproptosis in various cancer types, including colorectal cancer, lung cancer, gastric cancer, breast cancer, liver cancer and cutaneous melanoma. Furthermore, the effects of copper-related agents such as copper chelators and copper ionophores on cell proliferation, apoptosis, angiogenesis, tumor immunity, and chemotherapy resistance have been explored in cancer preclinical and clinical trials. These insights provide promising avenues for the development of prospective anticancer drugs aimed at inducing cuproptosis.

Repurposing disulfiram with CuET nanocrystals: Enhancing anti-pyroptotic effect through NLRP3 inflammasome inhibition for treating inflammatory bowel diseases

Drug repurposing offers a valuable strategy for identifying new therapeutic applications for existing drugs. Recently, disulfiram (DSF), a drug primarily used for alcohol addiction treatment, has emerged as a potential treatment for inflammatory diseases by inhibiting pyroptosis, a form of programmed cell death. The therapeutic activity of DSF can be further enhanced by the presence of Cu2+, although the underlying mechanism of this enhancement remains unclear. In this study, we investigated the mechanistic basis of Cu2+-induced enhancement and discovered that it is attributed to the formation of a novel copper ethylthiocarbamate (CuET) complex. CuET exhibited significantly stronger anti-pyroptotic activity compared to DSF and employed a distinct mechanism of action. However, despite its potent activity, CuET suffered from poor solubility and limited permeability, as revealed by our druggability studies. To overcome these intrinsic limitations, we developed a scalable method to prepare CuET nanocrystals (CuET NCs) using a metal coordination-driven self-assembly approach. Pharmacokinetic studies demonstrated that CuET NCs exhibited a 6-fold improvement in bioavailability. Notably, CuET NCs exhibited high biodistribution in the intestine, suggesting their potential application for the treatment of inflammatory bowel diseases (IBDs). To evaluate their therapeutic efficacy in vivo, we employed a murine model of DSS-induced colitis and observed that CuET NCs effectively attenuated inflammation and ameliorated colitis symptoms. Our findings highlight the discovery of CuET as a potent anti-pyroptotic agent, and the development of CuET NCs represents a novel approach to enhance the druggability of CuET.

Nanomedicine-based disulfiram and metal ion co-delivery strategies for cancer treatment

Disulfiram (DSF) is a second-line drug for the clinical treatment of alcoholism and has long been proven to be safe for use in clinical practice. In recent years, researchers have discovered the cancer-killing activity of DSF, which is highly dependent on the presence of metal ions, particularly copper ions. Additionally, free DSF is highly unstable and easily degraded within few minutes in blood circulation. Therefore, an ideal DSF formulation should facilitate the co-delivery of metal ions and safeguard the DSF throughout its biological journey before reaching the targeted site. Extensive research have proved that nanotechnology based formulations can effectively realize this goal by strategic encapsulation therapeutic agents within nanoparticle. To be more specific, this is accomplished through precise delivery, coordinated release of metal ions at the tumor site, thereby amplifying its cytotoxic potential. Beyond traditional co-loading techniques, innovative approaches such as DSF-metal complex and metal nanomaterials, have also demonstrated promising results at the animal model stage. This review aims to elucidate the anticancer mechanism associated with DSF and its reliance on metal ions, as well as to provide a comprehensive overview of recent advances in the arena of nanomedicine based co-delivery strategies for DSF and metal ion in the context of cancer therapy.

Combination of disulfiram and Copper-Cysteamine nanoparticles induces mitochondria damage and promotes apoptosis in endometrial cancer

Endometrial cancer (EC) stands as one of the most prevalent gynecological malignancies affecting women, with its incidence and disease-related mortality steadily on the rise. Disulfiram (DSF), an FDA-approved medication primarily used for treating alcohol addiction, has exhibited promising anti-tumor properties. Studies have revealed DSF's capacity for enhanced anti-tumor activity, particularly when combined with copper. The novel Copper-Cysteamine (CuCy) compound, Cu3Cl(SR)2 (R[bond, double bond]CH2CH2NH2), showcases photodynamic effects and demonstrates significant anti-tumor potential under various conditions, including exposure to ultraviolet light, X-ray, microwave, and ultrasound. This study delves into exploring the synergistic anti-tumor effects and underlying mechanisms by utilizing copper-cysteamine in conjunction with DSF against endometrial cancer. The investigation involved comprehensive analyses encompassing in vitro experiments utilizing Ishikawa cells, in vivo studies, and transcriptomic analyses. Remarkably, the combined administration of both compounds at a low dose of 0.5 μM exhibited pronounced efficacy in impeding tumor growth, inhibiting blood vessel formation, and stimulating cell apoptosis. Notably, experiments involving transplanted tumors in nude mice vividly demonstrated the significant in vivo anti-tumor effects of this combination treatment. Detailed examination through transmission electron microscopy unveiled compelling evidence of mitochondrial damage, cellular swelling, and rupture, indicative of apoptotic changes in morphology due to the combined treatment. Moreover, transcriptomic analysis unveiled substantial downregulation of mitochondrial-related genes at the molecular level, coupled with a significant hindrance in the DNA repair pathway. These findings strongly suggest that the combined application of CuCy and DSF induces mitochondrial impairment in Ishikawa cells, thereby fostering apoptosis and ultimately yielding potent anti-tumor effects.

Reactivating Hippo by drug compounds to suppress gastric cancer and enhance chemotherapy sensitivity

The Hippo signaling pathway plays an essential role in organ size control and tumorigenesis. Loss of Hippo signal and hyper-activation of the downstream oncogenic YAP signaling are commonly observed in various types of cancers. We previously identified STRN3-containing PP2A phosphatase as a negative regulator of MST1/2 kinases (i.e., Hippo) in gastric cancer (GC), opening the possibility of selectively targeting the PP2Aa-STRN3-MST1/2 axis to recover Hippo signaling against cancer. Here, we further discovered 1) disulfiram (DSF), an FDA-approved drug, which can similarly block the binding of STRN3 to PP2A core enzyme and 2) CX-6258 (CX), a chemical inhibitor, that can disrupt the interaction between STRN3 and MST1/2, both allowing reactivation of Hippo activity to inhibit GC. More importantly, we found these two compounds, via an MST1/2 kinase-dependent manner, inhibit DNA repair to sensitize GC towards chemotherapy. In addition, we identified thiram, a structural analog of DSF, can function similarly to inhibit cancer cell proliferation or enhance chemotherapy sensitivity. Interestingly, inclusion of copper ion enhanced such effects of DSF and thiram on GC treatment. Overall, this work demonstrated that pharmacological targeting of the PP2Aa-STRN3-MST1/2 axis by drug compounds can potently recover Hippo signal for tumor treatment.

Precision targeting of CuET overload to disrupt mitochondrial unfolded protein response by integrated liposome

Mitochondria in breast cancer play a critical role in survival and adaptation to dynamic environments. Thus, targeting mitochondria emerges as a promising therapeutic strategy for breast cancer. However, the adaptive unfolded protein response in mitochondria (UPRmt) due to mitochondrial unspecific distribution might contribute to diminished therapeutic outcomes. Herein, mitochondrial targeting liposome agents (CTPP-Lipid) are constructed and adopted for delivering the copper ion (CuET-DSF), which is especially sensitive for mitochondria-abundant breast tumors. In brief, the CTPP-Lipid@CuET achieves the goal of Cu2+ overloading by mitochondria targeting delivery. This rapidly increases ROS production, disrupts mitochondrial structure, and avoids the adaptive UPRmt formation, finally leading to apoptosis of breast cancer cells. In general, the Cu2+ overloading at mitochondria by CTPP-Lipid@CuET is a potential strategy for antitumor therapy, providing new insights into breast tumor therapy.

Current Trends on the Involvement of Zinc, Copper, and Selenium in the Process of Hepatocarcinogenesis

Numerous nutritional factors increase the risk of hepatocellular carcinoma (HCC) development. The dysregulation of zinc, copper, and selenium homeostasis is associated with the occurrence of HCC. The impairment of the homeostasis of these essential trace elements results in oxidative stress, DNA damage, cell cycle progression, and angiogenesis, finally leading to hepatocarcinogenesis. These essential trace elements can affect the microenvironment in HCC. The carrier proteins for zinc and copper and selenium-containing enzymes play important roles in the prevention or progression of HCC. These trace elements enhance or alleviate the chemosensitivity of anticancer agents in patients with HCC. The zinc, copper, or selenium may affect the homeostasis of other trace elements with each other. Novel types of cell death including ferropotosis and cupropotosis are also associated with hepatocarcinogenesis. Therapeutic strategies for HCC that target these carrier proteins for zinc and copper or selenium-containing enzymes have been developed in in vitro and in vivo studies. The use of zinc-, copper- or selenium-nanoparticles has been considered as novel therapeutic agents for HCC. These results indicate that zinc, copper, and selenium may become promising therapeutic targets in patients with HCC. The clinical application of these agents is an urgent unmet requirement. This review article highlights the correlation between the dysregulation of the homeostasis of these essential trace elements and the development of HCC and summarizes the current trends on the roles of these essential trace elements in the pathogenesis of hepatocarcinogenesis.

An In Situ Chemotherapy Drug Combined with Immune Checkpoint Inhibitor for Chemoimmunotherapy

Clinically, cancer chemotherapy still faces unsatisfactory efficacy due to drug resistance and severe side effects, including tiredness, hair loss, feeling sick, etc. The clinical benefits of checkpoint inhibitors have revived hope for cancer immunotherapy, but the objective response rate of immune checkpoint inhibitors remains around 10-40%. Herein, two types of copper-doped mesoporous silica nanoparticles (MS-Cu-1 with a diameter of about 30 nm and MS-Cu-2 with a diameter of about 200 nm) were synthesized using a one-pot method. Both MS-Cu-1 and MS-Cu-2 nanoparticles showed excellent tumor microenvironment regulation properties with elevated extracellular and intracellular ROS generation, extracellular and intracellular oxygenation, and intracellular GSH depletion. In particular, MS-Cu-2 nanoparticles demonstrated a better microenvironment modulation effect than MS-Cu-1 nanoparticles. The DSF/MS-Cu composites with disulfiram (DSF) and copper co-delivery characteristics were prepared by a straightforward method using chloroform as the solvent. Cell survival rate and live/dead staining results showed that DSF and MS-Cu alone were not toxic to LLC cells, while a low dose of DSF/MS-Cu (1-10 μg/mL) showed a strong cell-killing effect. In addition, MS-Cu-2 nanoparticles released more Cu2+ in a weakly acidic environment (pH = 5) than in a physiological environment (pH = 7.4), and the Cu2+ released was 41.72 ± 0.96 mg/L in 1 h under weakly acidic conditions. UV-visible absorption spectrometry confirmed the production of tumor-killing drugs (CuETs). The intratumoral injection of DSF/MS-Cu significantly inhibited tumor growth in vivo by converting nontoxic DSF/MS-Cu into toxic CuETs. The combination of DSF/MS-Cu and anti-CTLA-4 antibody further inhibited tumor growth, showing the synergistic effect of DSF/MS-Cu and immune checkpoint inhibitors.

Subcutaneous Rapid Dissolution Microneedle Patch Integrated with CuO2 and Disulfiram for Augmented Antimelanoma Efficacy through Multimodal Synergy of Photothermal Therapy, Chemodynamic Therapy, and Chemotherapy

Melanoma is a malignancy of the skin that is resistant to conventional treatment, necessitating the development of effective and safe new therapies. The percutaneous microneedle (MN) system has garnered increasing interest as a viable treatment option due to its high efficacy, minimal invasiveness, painlessness, and secure benefits. In this investigation, a sensitive MN system with multiple functions was created to combat melanoma effectively. This MN system utilized polyvinylpyrrolidone (PVP) as microneedle substrates and biocompatibility panax notoginseng polysaccharide (PNPS) as microneedle tips, which encapsulated PVP-stabilized CuO2 nanoparticles as a therapeutic agent and disulfiram-containing F127 micelles to enhance the tumor treatment effect. The MN system had sufficient mechanical properties to pierce the skin, and the excellent water solubility of PNPS brought high-speed dissolution properties under the bio conditions, allowing the MNs to effectively penetrate the skin and deliver the CuO2 nanoparticles as well as the drug-loaded micelles to the melanoma site. CuO2 nanoparticles released by the MN system generated Cu2+ and H2O2 in the tumor acidic environment to achieve self-supply of hydrogen peroxide to chemodynamic therapy (CDT). In addition, Cu2+ was chelated with disulfiram to produce CuET, which killed tumor cells. And the MN system had excellent near-infrared (NIR) photothermal properties due to the loading of CuO2 nanoparticles and induced localized thermotherapy in the melanoma region to further inhibit tumor growth. Thus, the designed MN system accomplished effective tumor suppression and minimal side effects in vivo via combined therapy, offering patients a safe and effective option for melanoma treatment.

A disulfiram/copper gluconate co-loaded bi-layered long-term drug delivery system for intraperitoneal treatment of peritoneal carcinomatosis

To develop a long-term drug delivery system for the treatment of primary and metastatic peritoneal carcinoma (PC) by intraperitoneal (IP) injection, a disulfiram (DSF)/copper gluconate (Cu-Glu)-co-loaded bi-layered poly (lactic acid-coglycolic acid) (PLGA) microspheres (Ms) - thermosensitive hydrogel system (DSF-Ms-Cu-Glu-Gel) was established. Rate and mechanisms of drug release from DSF-Ms-Cu-Glu-Gel were explored. The anti-tumor effects of DSF-Ms-Cu-Glu-Gel by IP injection were evaluated using H22 xenograft tumor model mice. The accumulative release of DSF from Ms on the 10th day was 83.79% without burst release. When Ms were dispersed into B-Gel, burst release at 24 h decreased to 14.63%. The results showed that bis (diethyldithiocarbamate)-copper (Cu(DDC)2) was formed in DSF-Ms-Cu-Glu-Gel and slowly released from B-Gel. In a pharmacodynamic study, the mount of tumor nodes and ascitic fluid decreased in the DSF-Ms-Cu-Glu-Gel group. This was because: (1) DSF-Ms-Cu-Glu-Gel system co-loaded DSF and Cu-Glu, and physically isolated DSF and Cu-Glu before injection to protect DSF; (2) space and water were provided for the formation of Cu(DDC)2; (3) could provide an effective drug concentration in the abdominal cavity for a long time; (4) both DSF and Cu(DDC)2 were effective anti-tumor drugs, and the formation of Cu(DDC)2 occurred in the abdominal cavity, which further enhanced the anti-tumor activity. Thus, the DSF-Ms-Cu-Glu-Gel system can be potentially used for the IP treatment of PC in the future.

Copper in hepatocellular carcinoma： A double-edged sword with therapeutic potentials

Copper is a necessary cofactor vital for maintaining biological functions, as well as participating in the development of cancer. A plethora of studies have demonstrated that copper is a double-edged sword, presenting both benefits and detriments to tumors. The liver is a metabolically active organ, and an imbalance of copper homeostasis can result in deleterious consequences to the liver. Hepatocellular carcinoma (HCC), the most common primary liver cancer, is a highly aggressive malignancy with limited viable therapeutic options. As research advances, the focus has shifted towards the relationships between copper and HCC. Innovatively, cuproplasia and cuproptosis have been proposed to depict copper-related cellular growth and death, providing new insights for HCC treatment. By summarizing the constantly elucidated molecular connections, this review discusses the mechanisms of copper in the pathogenesis, progression, and potential therapeutics of HCC. Additionally, we aim to tentatively provide a theoretical foundation and gospel for HCC patients.

NF-κB: a mediator that promotes or inhibits angiogenesis in human diseases?

The nuclear factor of κ-light chain of enhancer-activated B cells (NF-κB) signaling pathway, which is conserved in invertebrates, plays a significant role in human diseases such as inflammation-related diseases and carcinogenesis. Angiogenesis refers to the growth of new capillary vessels derived from already existing capillaries and postcapillary venules. Maintaining normal angiogenesis and effective vascular function is a prerequisite for the stability of organ tissue function, and abnormal angiogenesis often leads to a variety of diseases. It has been suggested that NK-κB signalling molecules under pathological conditions play an important role in vascular differentiation, proliferation, apoptosis and tumourigenesis by regulating the transcription of multiple target genes. Many NF-κB inhibitors are being tested in clinical trials for cancer treatment and their effect on angiogenesis is summarised. In this review, we will summarise the role of NF-κB signalling in various neovascular diseases, especially in tumours, and explore whether NF-κB can be used as an attack target or activation medium to inhibit tumour angiogenesis.

Enzyme/pH dual stimuli-responsive nanoplatform co-deliver disulfiram and doxorubicin for effective treatment of breast cancer lung metastasis

OBJECTIVES

Metastasis is still one of the main obstacles in the treatment of breast cancer. This study aimed to develop disulfiram (DSF) and doxorubicin (DOX) co-loaded nanoparticles (DSF-DOX NPs) with enzyme/pH dual stimuli-responsive characteristics to inhibit breast cancer metastasis.

METHODS

DSF-DOX NPs were prepared using the amphiphilic poly(ε-caprolactone)-b-poly(L-glutamic acid)-g-methoxy poly(ethylene glycol) (PCL-b-PGlu-g-mPEG) copolymer by a classical dialysis method. In vitro release tests, in vitro cytotoxicity assay, and anti-metastasis studies were conducted to evaluate pH/enzyme sensitivity and therapeutic effect of DSF-DOX NPs.

RESULTS

The specific pH and enzyme stimuli-responsiveness of DSF-DO NPs can be attributed to the transformation of secondary structure and the degradation of amide bonds in the PGlu segment, respectively. This accelerated drug release significantly increased the cytotoxicity to 4T1 cells. Compared with the control group, the DSF-DOX NPs showed a strong inhibition of in vitro metastasis with a wound healing rate of 36.50% and a migration rate of 18.39%. Impressively, in vivo anti-metastasis results indicated that the metastasis of 4T1 cells was almost completely suppressed by DSF-DOX NPs.

CONCLUSION

DSF-DOX NPs with controllable tumor site delivery of DOX and DSF were a prospectively potential strategy for metastatic breast cancer treatment.

Advancing Cancer Therapy with Copper/Disulfiram Nanomedicines and Drug Delivery Systems

Disulfiram (DSF) is a thiocarbamate based drug that has been approved for treating alcoholism for over 60 years. Preclinical studies have shown that DSF has anticancer efficacy, and its supplementation with copper (CuII) significantly potentiates the efficacy of DSF. However, the results of clinical trials have not yielded promising results. The elucidation of the anticancer mechanisms of DSF/Cu (II) will be beneficial in repurposing DSF as a new treatment for certain types of cancer. DSF's anticancer mechanism is primarily due to its generating reactive oxygen species, inhibiting aldehyde dehydrogenase (ALDH) activity inhibition, and decreasing the levels of transcriptional proteins. DSF also shows inhibitory effects in cancer cell proliferation, the self-renewal of cancer stem cells (CSCs), angiogenesis, drug resistance, and suppresses cancer cell metastasis. This review also discusses current drug delivery strategies for DSF alone diethyldithocarbamate (DDC), Cu (II) and DSF/Cu (II), and the efficacious component Diethyldithiocarbamate-copper complex (CuET).

Addressing the gaps in homeostatic mechanisms of copper and copper dithiocarbamate complexes in cancer therapy: a shift from classical platinum-drug mechanisms

The platinum drug, cisplatin, is considered as among the most successful medications in cancer treatment. However, due to its inherent toxicity and resistance limitations, research into other metal-based non-platinum anticancer medications with diverse mechanisms of action remains an active field. In this regard, copper complexes feature among non-platinum compounds which have shown promising potential as effective anticancer drugs. Moreover, the interesting discovery that cancer cells can alter their copper homeostatic processes to develop resistance to platinum-based treatments leads to suggestions that some copper compounds can indeed re-sensitize cancer cells to these drugs. In this work, we review copper and copper complexes bearing dithiocarbamate ligands which have shown promising results as anticancer agents. Dithiocarbamate ligands act as effective ionophores to convey the complexes of interest into cells thereby influencing the metal homeostatic balance and inducing apoptosis through various mechanisms. We focus on copper homeostasis in mammalian cells and on our current understanding of copper dysregulation in cancer and recent therapeutic breakthroughs using copper coordination complexes as anticancer drugs. We also discuss the molecular foundation of the mechanisms underlying their anticancer action. The opportunities that exist in research for these compounds and their potential as anticancer agents, especially when coupled with ligands such as dithiocarbamates, are also reviewed.

Preparation and anticancer actions of CuET-nanoparticles dispersed by bovine serum albumin

Diethyldithiocarbamate-copper complex (CuET) shows promising anticancer effect; nonetheless, preclinical evaluations of CuET are hindered due to poor solubility. We prepared bovine serum albumin (BSA)-dispersed CuET nanoparticles (CuET-NPs) to overcome the shortcoming. Results from a cell-free redox system demonstrated that CuET-NPs reacted with glutathione, leading to form hydroxyl radical. Glutathione-mediated production of hydroxyl radicals may help explain why CuET selectively kills drug-resistant cancer cells with higher levels of glutathione. CuET-NPs dispersed by autoxidation products of green tea epigallocatechin gallate (EGCG) also reacted with glutathione; however, the autoxidation products eradicated hydroxyl radicals; consequently, such CuET-NPs exhibited largely compromised cytotoxicity, suggesting that hydroxyl radical is a crucial mediator of CuET anticancer activity. In cancer cells, BSA-dispersed CuET-NPs exhibited cytotoxic activities equivalent to CuET and induced protein poly-ubiquitination. Moreover, the reported powerful inhibition of CuET on colony formation and migration of cancer cells could be replicated by CuET-NPs. These similarities demonstrate BSA-dispersed CuET-NPs is identical to CuET. Thus, we advanced to pilot toxicological and pharmacological evaluations. CuET-NPs caused hematologic toxicities in mice and induced protein poly-ubiquitination and apoptosis of cancer cells inoculated in mice at a defined pharmacological dose. Given high interest in CuET and its poor solubility, BSA-dispersed CuET-NPs pave the way for preclinical evaluations.

In Situ Synthesis of a Tumor-Microenvironment-Responsive Chemotherapy Drug

Current chemotherapy still suffers from unsatisfactory therapeutic efficacy, multi-drug resistance, and severe adverse effects, thus necessitating the development of techniques to confine chemotherapy drugs in the tumor microenvironment. Herein, we fabricated nanospheres of mesoporous silica (MS) doped with Cu (MS-Cu) and polyethylene glycol (PEG)-coated MS-Cu (PEG-MS-Cu) as exogenous copper supply systems to tumors. The synthesized MS-Cu nanospheres showed diameters of 30-150 nm with Cu/Si molar ratios of 0.041-0.069. Only disulfiram (DSF) and only MS-Cu nanospheres showed little cytotoxicity in vitro, whereas the combination of DSF and MS-Cu nanospheres showed significant cytotoxicity against MOC1 and MOC2 cells at concentrations of 0.2-1 μg/mL. Oral DSF administration in combination with MS-Cu nanospheres intratumoral or PEG-MS-Cu nanospheres intravenous administration showed significant antitumor efficacy against MOC2 cells in vivo. In contrast to traditional drug delivery systems, we herein propose a system for the in situ synthesis of chemotherapy drugs by converting nontoxic substances into antitumor chemotherapy drugs in a specific tumor microenvironment.

Systems biology strategy through integrating metabolomics and network pharmacology to reveal the mechanisms of Xiaopi Hewei Capsule improves functional dyspepsia

Functional dyspepsia (FD) is one of the more common functional disorders, with a prevalence of 20-25 %. It seriously affects the quality life of patients. Xiaopi Hewei Capsule (XPHC) is a classic formula originated from the Chinese Miao minority. Clinical studies have demonstrated that XPHC can effectively alleviate the symptoms of FD, but the molecular mechanism has not been elucidated. The purpose of this work is to investigate the mechanism of XPHC on FD by integrating metabolomics and network pharmacology. The mice models of FD were established, and gastric emptying rate, small intestine propulsion rate, serum level of motilin and gastrin were evaluate to study the interventional effect of XPHC on FD. Next, a metabolomics strategy has been developed to screen differential metabolites and related metabolic pathways induced by XPHC. Then, prediction of active compounds, targets and pathways of XPHC in treating FD were carried out by commonly used network pharmacological method. Finally, two parts of the results were integrated to investigate therapeutic mechanism of XPHC on FD, which were preliminary validated based on molecular docking. Thus, twenty representative different metabolites and thirteen related pathways of XPHC in treating FD were identified. Most of these metabolites were restored using modulation after XPHC treatment. The results of the network pharmacology analysis showed ten crucial compounds and nine hub genes related to the treatment of FD with XPHC. The further integrated analysis focused on four key targets, such as albumin (ALB), epidermal growth factor receptor (EGFR), tumor necrosis factor (TNF) and roto-oncogene tyrosine-protein kinase Src (SRC), and three representative biomarkers such as citric acid, L-leucine and eicosapentaenoic acid. Furthermore, molecular docking results showed that ten bioactive compounds from XPHC have good binding interactions with the four key genes. The functional enrichment analysis indicated that the potential mechanism of XPHC in treating FD was mainly associated with energy metabolism, amino acid metabolism, lipid metabolism, inflammatory reactions and mucosal repair. Our work confirms that network pharmacology-integrated metabolomics strategyis a powerful means to reveal the therapeutic mechanisms of XPHC improves FD, which contribute its further scientific research.

Clinical, pharmacological, and formulation evaluation of disulfiram in the treatment of glioblastoma - a systematic literature review

INTRODUCTION

Glioblastoma (GB) is one of the most challenging central nervous system (CNS) tumors in treatment options and response, urging the development of novel management strategies. The anti-alcoholism drug, disulfiram (DS), has a potential anticancer activity, and its complex mechanism of action is assumed to be well exploited against the heterogeneous GB.

AREA COVERED

Through a systematic literature review about repositioning DS to GB treatment, an evaluation of the clinical, pharmacological, and formulation strategies is provided to specify the challenges of drug delivery and thus to advance its clinical translation. From six databases, 35 articles were selected, including case report (1); clinical trials (3); original articles mainly representing in vitro and preclinical pharmacological data, and 10 dealing with technological approaches.

EXPERT OPINION

The repositioning of DS in GB treatment is facing drug and tumor-associated limitations due to the oral drug's low bioavailability, unwanted metabolism, and inefficient delivery to brain-tumor tissue. Development strategies using molecular encapsulation of DS and the parenteral dosage forms improve the anticancer pharmacology of the drug. The development of optimized drug delivery systems (DDS) shows promise for the clinical translation of DS into GB adjuvant therapy.

Comprehensive analysis of cuproptosis-related long non-coding RNA signature and personalized therapeutic strategy of breast cancer patients

Background

Breast cancer (BC) is considered to be one of the primary causes of cancer deaths in women. Cuproptosis was suggested to play an important role in tumor proliferation and tumor immune microenvironment. Therefore, an investigation was conducted to identify the relationship between cuproptosis-related long non-coding RNAs (lncRNAs) and BC prognosis.

Method

Based on The Cancer Genome Atlas (TCGA), nine cuproptosis-related lncRNAs were identified by Pearson's analysis and Cox regression analysis to create a cuproptosis-related lncRNA signature. Subsequently, patients with BC were divided into high-risk and low-risk groups. The Kaplan-Meier curves and a time-dependent receiver operating characteristic (ROC) analysis were employed to elucidate the predictive capability of the signature. After that, the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis was conducted by Gene Set Enrichment Analysis (GSEA), and the lncRNA-mRNA co-expression network was established by Cytoscape software. Furthermore, the ESTIMATE score was calculated, and the immune cell type component analysis was conducted. Eventually, immunotherapy response analysis was applied to identify the predictive power of cuproptosis-related lncRNAs to tumor immunotherapy response, including immune checkpoint gene expression levels, tumor mutational burden (TMB), and microsatellite instability (MSI).

Results

Patients with BC in the low-risk groups showed better clinical outcomes. The KEGG pathways in the high-risk groups were mainly enriched in immune response and immune cell activation. Furthermore, the ESTIMATE scores were higher in the low-risk groups, and their immune cell infiltrations were dramatically different from those of the high-risk groups. The low-risk groups were shown to have higher infiltration levels of CD8+ T cells and TMB-high status, resulting in better response to immunotherapies.

Conclusion

The findings of this study revealed that the nine-cuproptosis-related lncRNA risk score was an independent prognostic factor for BC. This signature was a potential predictor for BC immunotherapy response. What we found will provide novel insight into immunotherapeutic treatment strategies in BC.

Recent Advances in Copper-Based Organic Complexes and Nanoparticles for Tumor Theranostics

Treatment of drug-resistant forms of cancer requires consideration of their hallmark features, such as abnormal cell death mechanisms or mutations in drug-responding molecular pathways. Malignant cells differ from their normal counterparts in numerous aspects, including copper metabolism. Intracellular copper levels are elevated in various cancer types, and this phenomenon could be employed for the development of novel oncotherapeutic approaches. Copper maintains the cell oxidation levels, regulates the protein activity and metabolism, and is involved in inflammation. Various copper-based compounds, such as nanoparticles or metal-based organic complexes, show specific activity against cancer cells according to preclinical studies. Herein, we summarize the major principles of copper metabolism in cancer cells and its potential in cancer theranostics.

Disulfiram enhances chemotherapeutic effects of doxorubicin liposomes against human hepatocellular carcinoma via activating ROS-induced cell stress response pathways

PURPOSE

Increasing evidences have revealed the anti-cancer effect of disulfiram. Current disulfiram-based cancer therapies still have limitations, such as poor tumor-targeting ability and insufficient studies on anti-tumor mechanisms.

METHODS

In the present study, tumor-targeting liposomes were prepared as drug carriers to increase retention of disulfiram in tumor cells. Then, anti-tumor efficacy of liposomes and the underlying mechanisms were investigated in in vitro, in vivo, and transcriptomic level.

RESULTS

The results showed that disulfiram enhanced sensitivity of human hepatocellular carcinoma cells to doxorubicin by 15-27-fold, and increased reactive oxygen species (ROS) production as well as caspase-dependent apoptosis. Inhibition of tumor migration and invasion by doxorubicin were further enhanced by disulfiram. In vivo study showed that disulfiram additive doxorubicin liposomes had better performance in suppressing tumor growth than single doxorubicin liposomes. Gene expression profiling found that cellular components destruction, cell stress, check point regulation, and immunoregulation were the main anti-tumor mechanisms of disulfiram. More importantly, disulfiram possessed a great potential to be a protein ubiquitination and murine double minute 4 (MDM4) targeting compound.

CONCLUSIONS

Due to its low price and good safety, it is worth to repurposing disulfiram as a chemotherapeutic drug. Furthermore, MDM4 may act as a biomarker for observation the clinical effect of disulfiram-based treatment.

Stabilization of the c-Myc Protein via the Modulation of Threonine 58 and Serine 62 Phosphorylation by the Disulfiram/Copper Complex in Oral Cancer Cells

MYC has a short half-life that is tightly regulated through phosphorylation and proteasomal degradation. Many studies have claimed that treatment with disulfiram (DSF) with or without copper ions can cause cancer cell death in a reactive oxygen species (ROS)-dependent manner in cancer cells. Our previous study showed that the levels of c-Myc protein and the phosphorylation of threonine 58 (T58) and serine 62 (S62) increased in DSF-Cu-complex-treated oral epidermoid carcinoma Meng-1 (OECM-1) cells. These abovementioned patterns were suppressed by pretreatment with an ROS scavenger, N-acetyl cysteine. The overexpression of c-Myc failed to induce hypoxia-inducible factor 1α protein expression, which was stabilized by the DSF-Cu complex. In this study, we further examined the regulatory mechanism behind the induction of the c-Myc of the DSF-Cu complex in an OECM-1 cell compared with a Smulow–Glickman (SG) human normal gingival epithelial cell. Our data showed that the downregulation of c-Myc truncated nick and p62 and the induction of the ratio of H3P/H3 and p-ERK/ERK might not be involved in the increase in the amount of c-Myc via the DSF/copper complexes in OECM-1 cells. Combined with the inhibitors for various signaling pathways and cycloheximde treatment, the increase in the amount of c-Myc with the DSF/copper complexes might be mediated through the increase in the stabilities of c-Myc (T58) and c-Myc (S62) proteins in OECM-1 cells. In SG cells, only the c-Myc (T58) protein was stabilized by the DSF-Cu (I and II) complexes. Hence, our findings could provide novel regulatory insights into the phosphorylation-dependent stability of c-Myc in DSF/copper-complex-treated oral squamous cell carcinoma.

Toxic metals in the regulation of epithelial-mesenchymal plasticity: demons or angels?

Epithelial cells can trans-differentiate into motile mesenchymal cells through a dynamic process known as epithelial-mesenchymal transition (EMT). EMT is crucial in embryonic development and wound healing but also contributes to human diseases such as organ fibrosis and cancer progression. Heavy metals are environmental pollutants that can affect human health in various ways, including causing cancers. The cytotoxicity and carcinogenicity of heavy metals are complex, and studies have demonstrated that some of these metals can affect the progress of EMT. Here, we focus on reviewing the roles of six environmentally common toxic metals concerning EMT: arsenic (AS), cadmium (Cd), cobalt (Co), chromium (Cr), nickel (Ni), and copper (Cu). Noteworthily, the effects of these elements on EMT may vary according to the form, dose, and exposure time; the dual role of heavy metals (e.g., AS, Cd, and Cu) on EMT is also observed, in which, sometimes they can promote while sometimes inhibit the EMT process. Given the vast number of toxicologically relevant metals that exist in nature, we believe a comprehensive understanding of their effects on EMT is required to dictate in what circumstances these metals act more likely as demons or angels.

Disulfiram/Copper induces antitumor activity against gastric cancer via the ROS/MAPK and NPL4 pathways

Disulfiram (DSF) is an anti-alcoholism medication with superior antitumor activity and clinical safety; its antitumor mechanisms in gastric cancer (GC) have not been fully explored. In the present work, low nontoxic concentrations of copper (Cu) ions substantially enhanced DSF’s antitumor activity, inhibiting the proliferation and growth of GC cell lines. DSF/Cu elevated the generation of reactive oxygen species (ROS), and apoptosis was induced in an ROS-dependent manner. This process might involve primary inhibition GC by DSF/Cu through induction of apoptosis via the ROS/mitogen-activated protein kinase pathway. Disordering transportation of ubiquitinated protein may also fuel the process. In summary, we found that DSF exerts antitumor effects on GC. DSF/Cu should be considered as adjunctive therapy for GC.

Application of Disulfiram and its Metabolites in Treatment of Inflammatory Disorders

Disulfiram has been used clinically for decades as an anti-alcoholic drug. Recently, several studies have demonstrated the anti-inflammatory effects of disulfiram and its metabolism, which can alleviate the progression of inflammation in vivo and in vitro. In the current study, we summarize the anti-inflammatory mechanisms of disulfiram and its metabolism, including inhibition of pyroptosis by either covalently modifying gasdermin D or inactivating nod-like receptor protein 3 inflammasome, dual effects of intracellular reactive oxygen species production, and inhibition of angiogenesis. Furthermore, we review the potential application of disulfiram and its metabolism in treatment of inflammatory disorders, such as inflammatory bowel disease, inflammatory injury of kidney and liver, type 2 diabetes mellitus, sepsis, uveitis, and osteoarthritis.

Copper (Ⅱ)/cis-platinum -loaded nanogels as an adjuvant potentiate disulfiram antitumor efficacy

Disulfiram (DSF) is nontoxic and exerts anticancer activity by forming highly toxic chelate via its metabolite diethyldithiocarbamate with transition metal ions. However, there are not enough such ions in the...

Leveraging disulfiram to treat cancer: Mechanisms of action, delivery strategies, and treatment regimens

Disulfiram (DSF) has been used as an alcoholism drug for 70 years. Recently, it has attracted increasing attention owing to the distinguished anticancer activity, which can be further potentiated by the supplementation of Cu²⁺. Although encouraging anticancer results are obtained in lab, the clinical outcomes of oral DSF are not satisfactory, which urges an in-depth understanding of the underlying mechanisms, bottlenecks, and proposal of potential methods to address the dilemma. In this review, a critical summarization of various molecular biological anticancer mechanisms of DSF/Cu²⁺ is provided and the predicament of orally delivering DSF in clinical oncotherapy is explained by the metabolic barriers. We highlight the recent advances in the DSF/Cu²⁺ delivery strategies and the emerging treatment regimens for cancer treatment. Last but not the least, we summarize the clinical trials regarding DSF and make a prospect of DSF/Cu-based cancer therapy.

Repurposing Disulfiram for Targeting of Glioblastoma Stem Cells: An In Vitro Study

Mesenchymal glioblastoma stem cells (GSCs), a subpopulation in glioblastoma that are responsible for therapy resistance and tumor spreading in the brain, reportedly upregulate aldehyde dehydrogenase isoform-1A3 (ALDH1A3) which can be inhibited by disulfiram (DSF), an FDA-approved drug formerly prescribed in alcohol use disorder. Reportedly, DSF in combination with Cu2+ ions exerts multiple tumoricidal, chemo- and radio-therapy-sensitizing effects in several tumor entities. The present study aimed to quantify these DSF effects in glioblastoma stem cells in vitro, regarding dependence on ALDH1A3 expression. To this end, two patient-derived GSC cultures with differing ALDH1A3 expression were pretreated (in the presence of CuSO4, 100 nM) with DSF (0 or 100 nM) and the DNA-alkylating agent temozolomide (0 or 30 µM) and then cells were irradiated with a single dose of 0-8 Gy. As read-outs, cell cycle distribution and clonogenic survival were determined by flow cytometry and limited dilution assay, respectively. As a result, DSF modulated cell cycle distribution in both GSC cultures and dramatically decreased clonogenic survival independently of ALDH1A3 expression. This effect was additive to the impairment of clonogenic survival by radiation, but not associated with radiosensitization. Of note, cotreatment with temozolomide blunted the DSF inhibition of clonogenic survival. In conclusion, DSF targets GSCs independent of ALDH1A3 expression, suggesting a therapeutic efficacy also in glioblastomas with low mesenchymal GSC populations. As temozolomide somehow antagonized the DSF effects, strategies for future combination of DSF with the adjuvant standard therapy (fractionated radiotherapy and concomitant temozolomide chemotherapy followed by temozolomide maintenance therapy) are not supported by the present study.

Co-delivery of nanoparticle and molecular drug by hollow mesoporous organosilica for tumor-activated and photothermal-augmented chemotherapy of breast cancer

BACKGROUND

In comparison with traditional therapeutics, it is highly preferable to develop a combinatorial therapeutic modality for nanomedicine and photothermal hyperthermia to achieve safe, efficient, and localized delivery of chemotherapeutic drugs into tumor tissues and exert tumor-activated nanotherapy. Biocompatible organic-inorganic hybrid hollow mesoporous organosilica nanoparticles (HMONs) have shown high performance in molecular imaging and drug delivery as compared to other inorganic nanosystems. Disulfiram (DSF), an alcohol-abuse drug, can act as a chemotherapeutic agent according to its recently reported effectiveness for cancer chemotherapy, whose activity strongly depends on copper ions.

RESULTS

In this work, a therapeutic construction with high biosafety and efficiency was proposed and developed for synergistic tumor-activated and photothermal-augmented chemotherapy in breast tumor eradication both in vitro and in vivo. The proposed strategy is based on the employment of HMONs to integrate ultrasmall photothermal CuS particles onto the surface of the organosilica and the molecular drug DSF inside the mesopores and hollow interior. The ultrasmall CuS acted as both photothermal agent under near-infrared (NIR) irradiation for photonic tumor hyperthermia and Cu2+ self-supplier in an acidic tumor microenvironment to activate the nontoxic DSF drug into a highly toxic diethyldithiocarbamate (DTC)-copper complex for enhanced DSF chemotherapy, which effectively achieved a remarkable synergistic in-situ anticancer outcome with minimal side effects.

CONCLUSION

This work provides a representative paradigm on the engineering of combinatorial therapeutic nanomedicine with both exogenous response for photonic tumor ablation and endogenous tumor microenvironment-responsive in-situ toxicity activation of a molecular drug (DSF) for augmented tumor chemotherapy.

Disulfiram Synergizes with SRC Inhibitors to Suppress the Growth of Pancreatic Ductal Adenocarcinoma Cells in Vitro and in Vivo

Disulfiram (DSF), an old anti-alcoholism drug, has emerged as a candidate for drug repurposing in oncology. In exploratory studies on its therapeutic effects, we unexpectedly discovered that DSF increased the phosphorylation of SRC, a proto-oncogene tyrosine-protein kinase elevated in 70% of pancreatic ductal adenocarcinoma (PDAC) cases. This serendipitous and novel finding led to our hypothesis for the current study which proposes DSF may synergize with SRC inhibitors in suppressing PDAC. Human PDAC PANC-1 and BXPC-3 cells were incubated with DSF chelated with copper (Cu2⁺), SRC inhibitors (PP2 and dasatinib), or transfected with lentiviral short hairpin RNA (shRNA), and their proliferation and apoptosis were analyzed. A xenograft model was employed to verify the in vitro results. The expression of key molecules was detected. DSF significantly inhibited cell proliferation and induced cell apoptosis by increasing the cleavage of poly ADP ribose polymerase (PARP), downregulating Bcl-2 and upregulating p27 in concentration- and time-dependent manners. DSF had little effect on signal transducer and activator of transcription 3 (STAT3) expression but inhibited its phosphorylation. DSF did not alter SRC expression but significantly increased its phosphorylation through upregulating actin filament associated protein 1 like 2 (AFAP1L2). DSF exhibited a synergistic effect, as analyzed by drug coefficient interactions, with either PP2, or dasatinib, or SRC depletion in suppressing PDAC cells in vitro and/or in vivo. The present results indicate DSF is a potential therapeutic drug, particularly when it is combined with SRC inhibitors, and warrant further studies on the pharmacological utility of DSF as a promising adjunct therapy for the treatment of PDAC.

In situ triggering antitumor efficacy of alcohol-abuse drug disulfiram through Cu-based metal-organic framework nanoparticles

Although approved as an alcohol-abuse drug, disulfiram (DSF) exhibited potential anticancer activity when chelated with copper (Cu). However, the low level of intrinsic Cu, toxicity originated from exogenous Cu supplementation, and poor stability of DSF in vivo severely limited its application in cancer treatment. Herein, we proposed an in situ DSF antitumor efficacy triggered system, taking advantages of Cu-based metal-organic framework (MOF). In detail, DSF was encapsulated into Cu-MOF nanoparticles (NPs) during its formation, and the obtained NPs were coated with hyaluronic acid to enhance the tumor targetability and biocompatibility. Notably, DSF loaded Cu-MOF NPs maintained stability and integrity without Cu2+ leakage in blood circulation, thus showing excellent biosafety. Once accumulating at tumor site, NPs were internalized into tumor cells via receptor-mediated endocytosis and released DSF and Cu2+ simultaneously in the hyaluronidase-enriched and acidic intracellular tumor microenvironment. This profile lead to in situ chelation reaction between DSF and Cu2+, generating toxic DSF/Cu complex against tumor cells. Both in vitro and in vivo results demonstrated the programmed degradation and recombination property of Cu-based MOF NPs, which facilitated the tumor-specific chemotherapeutic effects of DSF. This system provided a promising strategy for the application of DSF in tumor therapy.

Overview of Antabuse® (Disulfiram) in Radiation and Cancer Biology

Antabuse®, generic name disulfiram, has been extensively used in daily clinical practice to treat alcohol abuse. In vivo and in vitro experiments have demonstrated that disulfiram was capable of inhibiting tumor cell proliferation; clinical studies have indicated that the administration of this drug was associated with favorable survival, whilst in vitro experiments have elucidated the anticancer mechanism of disulfiram. In addition, radiation and cancer biology studies have shown that disulfiram can protect normal cells and sensitize tumor cells during radiotherapy. This review aims at describing the antitumor activity of disulfiram in both preclinical studies and clinical trials, whilst focusing on the advances of this drug in radiation and cancer biology, and the promise of repurposing it as a novel sensitizer to, and protector against, radiation on the incoming clinical studies.

A Phase 1 dose-escalation study of disulfiram and copper gluconate in patients with advanced solid tumors involving the liver using S-glutathionylation as a biomarker

Background

Disulfiram and metals inactivate key oncoproteins resulting in anti-neoplastic activity. The goal of this study was to determine the maximum tolerated dose of copper when administered with disulfiram in patients with advanced solid tumors and liver involvement.

Methods

Disulfiram 250 mg was administered daily in 28-day cycles. Four doses of copper gluconate were tested (2, 4, 6, and 8 mg of elemental copper) in a standard 3 + 3 dose escalation design. Patients were evaluated for dose limiting toxicities and response. Protein S-glutathionylation was evaluated as a pharmacodynamic marker.

Results

Twenty-one patients were enrolled and 16 patients were evaluable for dose limiting toxicities. Among the 21 patients, there was a median of 4 lines of prior chemotherapy. Five Grade 3 toxicities were observed (anorexia, elevated aspartate aminotransferase or AST, elevated alkaline phosphatase, fever, and fatigue). Response data was available for 15 patients. Four patients had stable disease with the longest duration of disease control being 116 days. The median duration of treatment for evaluable patients was 55 days (range 28–124). Reasons for discontinuation included functional decline, disease progression, and disease-associated death. Increased S-glutathionylation of serum proteins was observed with treatment.

Conclusion

Disulfiram 250 mg daily with copper gluconate (8 mg of elemental copper) was well-tolerated in patients with solid tumors involving the liver and was not associated with dose limiting toxicities. While temporary disease stabilization was noted in some patients, no objective responses were observed. Treatment was associated with an increase in S-glutathionylation suggesting that this combination could exert a suppressive effect on cellular growth and protein function.

Trial registration

NCT00742911, first posted 28/08/2008.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08242-4.

Differential Cytotoxicity Mechanisms of Copper Complexed with Disulfiram in Oral Cancer Cells

Disulfiram (DSF), an irreversible aldehyde dehydrogenase inhibitor, is being used in anticancer therapy, as its effects in humans are known and less adverse than conventional chemotherapy. We explored the potential mechanism behind the cytotoxicity of DSF-Cu⁺/Cu²⁺ complexes in oral epidermoid carcinoma meng-1 (OECM-1) and human gingival epithelial Smulow-Glickman (SG) cells. Exposure to CuCl₂ or CuCl slightly but concentration-dependently decreased cell viability, while DSF-Cu⁺/Cu²⁺ induced cell death in OECM-1 cells, but not SG cells. DSF-Cu⁺/Cu²⁺ also increased the subG1 population and decreased the G1, S, and G2/M populations in OECM-1 cells, but not SG cells, and suppressed cell proliferation in both OECM-1 and SG cells. ALDH enzyme activity was inhibited by CuCl and DSF-Cu⁺/Cu²⁺ in SG cells, but not OECM-1 cells. ROS levels and cellular senescence were increased in DSF-Cu⁺/Cu²⁺-treated OECM-1 cells, whereas they were suppressed in SG cells. DSF-Cu⁺/Cu²⁺ induced mitochondrial fission in OECM-1 cells and reduced mitochondrial membrane potential. CuCl₂ increased but DSF- Cu²⁺ impaired oxygen consumption rates and extracellular acidification rates in OECM-1 cells. CuCl₂ stabilized HIF-1α expression under normoxia in OECM-1 cells, and complex with DSF enhanced that effect. Levels of c-Myc protein and its phosphorylation at Tyr58 and Ser62 were increased, while levels of the N-terminal truncated form (Myc-nick) were decreased in DSF-Cu⁺/Cu²-treated OECM-1 cells. These effects were all suppressed by pretreatment with the ROS scavenger NAC. Overexpression of c-Myc failed to induce HIF-1α expression. These findings provide novel insight into the potential application of DSF-CuCl₂ complex as a repurposed agent for OSCC cancer therapy.

The revival of dithiocarbamates: from pesticides to innovative medical treatments

Dithiocarbamates (DTCs) have been used for various applications, including as hardening agents in rubber manufacturing, as fungicide in agriculture, and as medications to treat alcohol misuse disorder. The multi-faceted effects of DTCs rely mainly on metal binding abilities and a high reactivity with thiol groups. Therefore, the list of potential applications is still increasing, exemplified by the US Food and Drug Administration approval of disulfiram (Antabuse) and its metabolite diethyldithiocarbamate in clinical trials against cancer, human immunodeficiency virus, and Lyme disease, as well as new DTC-related compounds that have been synthesized to target diseases with unmet therapeutic needs. In this review, we will discuss the latest progress of DTCs as anti-cancer agents and provide a summary of the mechanisms of action. We will explain the expansion of DTCs' activity in the fields of microbiology, neurology, cardiology, and ophthalmology, thereby providing evidence for the important role and therapeutic potential of DTCs as innovative medical treatments.

Nose-to-brain delivery of disulfiram nanoemulsion in situ gel formulation for glioblastoma targeting therapy

Glioblastoma (GBM) is a difficult-to-treat cancer, likely attributed to the blood brain barrier and drug resistance. Nose-to-brain drug delivery is a direct and non-invasive pathway for brain targeting with low systemic toxicity. Disulfiram (DSF) has shown its effectiveness against GBM, especially with copper ion (Cu). In this work, we designed a DSF loaded ion-sensitive nanoemulsion in situ gel (DSF-INEG) that was delivered intranasally along with Cu to the rat brains for the GBM treatment. The developed DSF-INEG nanomedicine showed a suitable particle size of 63.4 ± 1.1 nm and zeta potential of -23.5 ± 0.2 mV with a favorable gelling ability and prolonged DSF release. The results in vitro indicate DSF-INEG/Cu effectively inhibited the proliferation of both C6 and U87 cells. Besides, the excellent brain-targeting efficacy via nose-to-brain delivery was proved by the highest fluorescence signal of Cy5.5-INEG in the rat brains. Moreover, GFP imaging showed enhanced tumor growth inhibition of the rats by the DSF-INEG/Cu treatment, and their median survival time was 1.6 and 1.2 folds than those of the rats in the control and DSF/Cu treated groups, respectively, with no obvious histopathological damage to normal tissues. Overall, DSF-INEG/Cu could be a promising intranasal nanomedicine for effective GBM treatment.

B3GNT3 overexpression promotes tumor progression and inhibits infiltration of CD8+ T cells in pancreatic cancer

Beta-1,3-N-acetylglucosaminyltransferase 3 (B3GNT3) has been associated with tumor progression in several solid tumors, and inhibits CD8⁺ T cell-mediated anti-tumor immunity in breast cancer. However, little is known about the potential functions of B3GNT3 in immunosuppression in pancreatic cancer (PC). This study on B3GNT3 aims to provide novel insights into the mechanisms of immune suppression or evasion in PC. To this end, the clinical significance and oncologic roles of B3GNT3 were investigated through bioinformatic analysis and in vitro studies. Potential associations between the expression of B3GNT3 and tumor immunity were mainly analyzed by single-sample gene set enrichment analysis (ssGSEA) and immunofluorescence in tissue microarray (TMA). B3GNT3 overexpression was observed in PC tissue and was associated with larger tumor sizes, higher histologic grades, and poorer overall survival (OS). B3GNT3 overexpression was associated with the mutation status and expression of driver genes, especially for KRAS and SMAD4. B3GNT3 knockdown inhibited the proliferation, invasion, and epithelial-mesenchymal transition (EMT) of PC cells. B3GNT3 overexpression significantly correlated with decreased infiltration of tumor infiltrating lymphocytes (TILs), especially CD8⁺ T cells. Overall, our results indicate that B3GTN3 plays a novel role in tumor progression and immunosuppression, thus serving as a potential therapeutic target in PC.

The Evolving Role of Disulfiram in Radiobiology and the Treatment of Breast Cancer

Disulfiram (DSF), also known as “Antabuse”, has been widely used in clinical practice to treat alcoholism. In the past decades, both in vivo and in vitro experiments showed that DSF has strong anti-cancer activity, there were some clinical studies indicated the administration of this drug was associated with favorable survival in breast cancer. It is also evident that DSF has a radioprotective effect on normal cells and could be utilized during the course of radiation therapy. Moreover, increasing evidences demonstrated the role of DSF in enhancing the radiosensitivity of tumor cells in number of alternative mechanisms. Recent studies have also elaborated the anticancer mechanism of DSF in tumor cells. This review summarizes the anticancer activity of DSF both in preclinical studies and clinical trials, focuses on the advances of this drug in radiobiology and the treatment of breast cancer, and reveals the promising of repurposing DSF as a novel radiosensitizer and radioprotector in further clinical trials.

Therapeutic effect of disulfiram inclusion complex embedded in hydroxypropyl-β-cyclodextrin on intracranial glioma-bearing male rats via intranasal route

The unique environment of brain poses a huge challenge for drug development aimed at combatting glioblastoma (GBM) due to poor organ targeting. Intranasal administration is often considered as an attractive route directly into brain by not only circumventing the blood brain barrier and but also avoiding the hepatic first-pass effect. Disulfiram (DSF) is an old alcohol-aversion drug that has anti-tumor activities against diverse cancer types such as GBM in preclinical studies, especially when it is combined with cupper ion (Cu). In this study, DSF was embedded in hydroxypropyl-β-cyclodextrin (HP-β-CD) to prepare a DSF inclusion complex with the enhanced solubility, anti-GBM activity and high safety in vitro. The highest fluorescence signal of Cy5.5/HP-β-CD in the male rat brains showed the strong brain-targeting of nose-to-brain drug delivery. Therapeutic effects of DSF/HP-β-CD combined with Cu (DSF/HP-β-CD/Cu) on intracranial glioma-bearing male rats via different drug delivery routes were then investigated. DSF/HP-β-CD/Cu administrated by the intranasal route effectively inhibited tumor growth and migration, promoted apoptosis, and achieved 36.8% and 18.2% prolonged median survival time comparing to those of model rats by oral and intravenous administrations, respectively. Moreover, no obvious histopathological damage to normal tissues was observed by H&E staining. Overall, DSF/HP-β-CD/Cu could be a promising intranasal formulation for the effective GBM treatment.

Cellular Plasticity and Tumor Microenvironment in Gliomas: The Struggle to Hit a Moving Target

Brain tumors encompass a diverse group of neoplasias arising from different cell lineages. Tumors of glial origin have been the subject of intense research because of their rapid and fatal progression. From a clinical point of view, complete surgical resection of gliomas is highly difficult. Moreover, the remaining tumor cells are resistant to traditional therapies such as radio- or chemotherapy and tumors always recur. Here we have revised the new genetic and epigenetic classification of gliomas and the description of the different transcriptional subtypes. In order to understand the progression of the different gliomas we have focused on the interaction of the plastic tumor cells with their vasculature-rich microenvironment and with their distinct immune system. We believe that a comprehensive characterization of the glioma microenvironment will shed some light into why these tumors behave differently from other cancers. Furthermore, a novel classification of gliomas that could integrate the genetic background and the cellular ecosystems could have profound implications in the efficiency of current therapies as well as in the development of new treatments.

An Updated Review of Disulfiram: Molecular Targets and Strategies for Cancer Treatment

Repurposing already approved drugs as new anticancer agents is a promising strategy considering the advantages such as low costs, low risks and less time-consumption. Disulfiram (DSF), as the first drug for antialcoholism, was approved by the U.S. Food and Drug Administration (FDA) over 60 years ago. Increasing evidence indicates that DSF has great potential for the treatment of various human cancers. Several mechanisms and targets of DSF related to cancer therapy have been proposed, including the inhibition of ubiquitin-proteasome system (UPS), cancer cell stemness and cancer metastasis, and alteration of the intracellular reactive oxygen species (ROS). This article provides a brief review about the history of the use of DSF in humans and its molecular mechanisms and targets of anticancer therapy, describes DSF delivery strategies for cancer treatment, summarizes completed and ongoing cancer clinical trials involving DSF, and offers strategies to better use DSF in cancer therapies.

A CD44-targeted Cu(ii) delivery 2D nanoplatform for sensitized disulfiram chemotherapy to triple-negative breast cancer

Recent studies have suggested that the anticancer activity of disulfiram (DSF, an FDA-approved alcohol-abuse drug) is Cu-dependent. Low system toxicity and explicit pharmacokinetic characteristics of DSF necessitate safe and effective Cu supplementation in local lesion for further applications. Herein, we presented a new conceptual 'nanosized coordination transport' strategy of Cu(ii) that was realized in porphyrin-based metal-organic frameworks, Sm-TCPP, with strong binding ability to Cu(ii) due to their coordination interactions. Sm-TCPP(Cu) was coated by hyaluronic acid (HA) that termed by Sm-TCPP(Cu)@HA, acting as 'beneficial horse' to target the tumor-localized HA receptor (CD44), thus liberating Cu(ii) ions in cellular overexpressed reductants. The CD44-mediated Cu(ii) accumulation efficiency of Sm-TCPP(Cu)@HA was benchmarked in vitro and vivo against the free TCPP (Cu) via ICP-MS analysis. More importantly, the sensitization effects of Sm-TCPP(Cu)@HA on the anticancer activity of DSF were demonstrated in vivo and in vitro. This study offered a new class of targeted Cu supplements to sensitize DSF for the effective treatment of cancer and established a versatile methodology for constructing a safe and specific delivery of metal ions within living organisms.

The Ionophoric Activity of a Pro-Apoptotic VEGF165 Fragment on HUVEC Cells

Copper plays an important role as a regulator in many pathologies involving the angiogenesis process. In cancerogenesis, tumor progression, and angiogenic diseases, copper homeostasis is altered. Although many details in the pathways involved are still unknown, some copper-specific ligands have been successfully used as therapeutic agents. Copper-binding peptides able to modulate angiogenesis represent a possible way to value new drugs. We previously reported that a fragment (VEGF73-101) of vascular endothelial growth factor (VEGF165), a potent angiogenic, induced an apoptotic effect on human umbilical vein endothelial cells. The aim of this study was to investigate the putative copper ionophoric activity of VEGF73-101, as well as establish a relationship between the structure of the peptide fragment and the cytotoxic activity in the presence of copper(II) ions. Here, we studied the stoichiometry and the conformation of the VEGF73-101/Cu(II) complexes and some of its mutated peptides by electrospray ionization mass spectrometry and circular dichroism spectroscopy. Furthermore, we evaluated the effect of all peptides in the absence and presence of copper ions by cell viability and cytofuorimetric assays. The obtained results suggest that VEGF73-101 could be considered an interesting candidate in the development of new molecules with ionophoric properties as agents in antiangiogenic therapeutic approaches.

N-Oxide polymer-cupric ion nanogels potentiate disulfiram for cancer therapy

Disulfiram (DSF) exerts potent anticancer activity via the formation of chelates with copper or zinc ions in tumor tissues, but the low abundance of these ions in the tumor cannot sustain its antitumor activity. Herein, we show that a zwitterionic water-soluble N-oxide polymer, poly[2-(N-oxide-N,N-dimethylamino)ethyl methacrylate] (OPDMA), can complex cupric ions and form nanogels (OPDMA/Cu), which efficiently deliver copper ions to tumor tissue to potentiate DSF significantly for effective antitumor therapy.

Repurposing Disulfiram as An Anti-Cancer Agent: Updated Review on Literature and Patents

BACKGROUND

Despite years of success of most anti-cancer drugs, one of the major clinical problems is inherent and acquired resistance to these drugs. Overcoming the drug resistance or developing new drugs would offer promising strategies in cancer treatment. Disulfiram, a drug currently used in the treatment of chronic alcoholism, has been found to have anti-cancer activity.

OBJECTIVE

To summarize the anti-cancer effects of Disulfiram through a thorough patent review.

METHODS

This article reviews molecular mechanisms and recent patents of Disulfiram in cancer therapy.

RESULTS

Several anti-cancer mechanisms of Disulfiram have been proposed, including triggering oxidative stress by the generation of reactive oxygen species, inhibition of the superoxide dismutase activity, suppression of the ubiquitin-proteasome system, and activation of the mitogen-activated protein kinase pathway. In addition, Disulfiram can reverse the resistance to chemotherapeutic drugs by inhibiting the P-glycoprotein multidrug efflux pump and suppressing the activation of NF-kB, both of which play an important role in the development of drug resistance. Furthermore, Disulfiram has been found to reduce angiogenesis because of its metal chelating properties as well as its ability to inactivate Cu/Zn superoxide dismutase and matrix metalloproteinases. Disulfiram has also been shown to inhibit the proteasomes, DNA topoisomerases, DNA methyltransferase, glutathione S-transferase P1, and O6- methylguanine DNA methyltransferase, a DNA repair protein highly expressed in brain tumors. The patents described in this review demonstrate that Disulfiram is useful as an anti-cancer drug.

CONCLUSION

For years the FDA-approved, well-tolerated, inexpensive, orally-administered drug Disulfiram was used in the treatment of chronic alcoholism, but it has recently demonstrated anti-cancer effects in a range of solid and hematological malignancies. Its combination with copper at clinically relevant concentrations might overcome the resistance of many anti-cancer drugs in vitro, in vivo, and in patients.

Disulfiram and Its Copper Chelate Attenuate Cisplatin-Induced Acute Nephrotoxicity in Rats Via Reduction of Oxidative Stress and Inflammation

The use of cisplatin (CP) in chemotherapy of resistant cancers is limited due to its dose-dependent nephrotoxicity. Disulfiram (DSF), the aversion therapy for alcoholism, has recently emerged as an anticancer and chemopreventive agent. Its anticancer activity is potentiated in the presence of copper. However, such use of copper leads to several adverse effects. In the present study, the protective effect of DSF and its copper chelate (Cu-DEDC) against CP-induced nephrotoxicity in rats was evaluated. Nephrotoxicity was induced by a single intraperitoneal injection of CP (5 mg/kg). The treatment groups included control (vehicle treated), CP (CP-treated), CP + DSF (CP followed by DSF), CP + DSF + Cu (CP followed by DSF and CuCl₂), CP + Cu-DEDC (CP followed by Cu-DEDC), and CP + AMF (amifostine pre-treated and CP-treated). The DSF, Cu-DEDC, and CuCl₂ were administered orally at 50 mM/kg/day dose for 5 days post CP injection. AMF served as a standard chemo protectant, administered intravenously 30 min prior to CP. The markers of oxidative stress, inflammation, and kidney function estimated on the 6th day revealed that both DSF and Cu-DEDC significantly attenuated the CP-induced rise in the serum/urine creatinine and blood urea nitrogen (BUN). The CP-induced rise in serum alkaline phosphatase (ALPase) was reversed by these drugs. Both drugs reduced the levels of malondialdehyde and nitric oxide (NO) in kidney tissues. These drugs reversed CP-induced depletion of SOD, catalase, and GSH in the kidneys. There was a significant reduction in the CP-induced TNF-α and IL-1β production along with prevention of histological alterations. Above observations indicate that DSF and Cu-DEDC may have significance as adjuvants to protect against CP-induced nephrotoxicity.

The Mechanisms Underlying the Cytotoxic Effects of Copper Via Differentiated Embryonic Chondrocyte Gene 1

Copper is an essential trace element within cells, but it also exerts cytotoxic effects through induction of reactive oxygen species (ROS) production. To determine the mechanisms underlying copper-induced ROS production, we examined the effects of copper sulfate in HeLa cells. Exposure to copper sulfate led to dose-dependent decreases in HeLa cell viability, along with increases in the subG1 and G2/M populations and corresponding decreases in the G1 population. Copper sulfate also increased the levels of apoptosis, senescence, mitochondrial dysfunction, autophagy, ROS, and the expression of several stress proteins, including ATF3, c-Fos, DEC1 (differentiated embryonic chondrocyte gene 1), p21, p53, and HIF-1α (hypoxia-inducible factor 1 alpha). The suppression of copper-induced ROS generation by the ROS scavenger N-acetyl cysteine verified copper’s functional role, while the suppression of copper’s effects by the copper chelator disulfiram, confirmed its specificity. Selective induction of HIF-1α, p53, and phosphorylated ERK proteins by copper was blocked by the knockdown of the transcription factor DEC1, suggesting copper’s effects are mediated by DEC1. In addition to HeLa cells, copper also exerted cytotoxic effects in human endometrial (HEC-1-A) and lung (A549) adenocarcinoma cells, but not in normal human kidney (HEK293) or bronchial (Beas-2B) epithelial cells. These findings shed new light on the functional roles of copper within cells.