The role of copper in tumour angiogenesis

Transformation of metallo-elastomer grafts in a carotid artery interposition model over a year

Current vascular grafts, primarily Gore-Tex® and Dacron®, don't integrate with the host and have low patency in small-diameter vessels (<6 mm). Biomaterials that possess appropriate viscoelasticity, compliance, and high biocompatibility are essential for their application in small blood vessels. We have developed metal ion crosslinked poly(propanediol-co-(hydroxyphenyl methylene)amino-propanediol sebacate) (M-PAS), a biodegradable elastomer with a wide range of mechanical properties. We call these materials metallo-elastomers. An initial test on Zn-, Fe-, and Cu-PAS grafts reveals that Cu-PAS is the most suitable because of its excellent elastic recoil and well-balanced polymer degradation/tissue regeneration rate. Here we report host remodeling of Cu-PAS vascular grafts in rats over one year. 76 % of the grafts remain patent and >90 % of the synthetic polymer is degraded by 12 months. Extensive cell infiltration leads to a positive host remodeling. The remodeled grafts feature a fully endothelialized lumen. Circumferentially organized smooth muscle cells, elastin fibers, and widespread mature collagen give the neoarteries mechanical properties similar to native arteries. Proteomic analysis further reveals the presence of important vascular proteins in the neoarteries. Evidence suggests that Cu-PAS is a promising material for engineering small blood vessels.

Domestic dogs as environmental sentinel in comparative toxicologic pathology: Assessment of metals and rare earth elements concentrations in healthy and neoplastic mammary glands

Quantification of trace element concentrations in human and animal tissues has acquired great importance in the last few years, considering the pivotal role of these elements in several physiological and pathological processes. Variations in their concentrations appear to have a role in the development and advancement of diseases in both humans and animals, for example, cancer. The purpose of this study was to investigate the concentration of rare earth elements and metals in healthy and neoplastic Formalin-Fixed Paraffin-Embedded (FFPE) mammary gland tissue of dogs. All samples were processed to have a quantitative determination of inorganic elements including metals of known toxicological interest such as Pb, Cd, Tl, As, Hg, the trace elements Mn, Fe, Co, Cu, Zn, Se, and other elements including Cr, V, Mo, Ni, Sb, W, Sn. Moreover, rare earth elements (REEs) (Sc, Y, Lu, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb) were also investigated. Cu and Mo concentrations in mammary cancerous tissue were greater than those in normal mammary glands (p < 0.05). In non-neoplastic tissue increased concentrations of Cd, Co, Ni, Tl, and V were also reported (p < 0.05). The mammary tissue of healthy individuals had greater concentrations of REEs than the neoplastic mammary glands (p < 0.05). The results of our study confirmed differences in mammary inorganic element concentrations between healthy and neoplastic groups, highlighting the potential relevance of these fluctuations in toxicologic pathology.

Modulation of Metal Homeostasis for Cancer Therapy

Metal ions such as iron, zinc, copper, manganese, and calcium are essential for normal cellular processes, including DNA synthesis, enzyme activity, cellular signaling, and oxidative stress regulation. When the balance of metal homeostasis is disrupted, it can lead to various pathological conditions, including cancer. Thus, understanding the role of metal homeostasis in cancer has led to the development of anti-tumor strategies that specifically target the metal imbalance. Up to now, diverse small molecule-based chelators, ionophores, metal complexes, and metal-based nanomaterials have been developed to restore the normal balance of metals or exploit the dysregulation for therapeutic purposes. They hold great promise in inhibiting tumor growth, preventing metastasis, and enhancing the effectiveness of existing cancer therapies. In this review, we aim to provide a comprehensive summary of the strategies employed to modulate the homeostasis of iron, zinc, copper, manganese, and calcium for cancer therapy. Their modulation mechanisms for metal homeostasis are succinctly described, and their recent applications in the field of cancer therapy are discussed. At the end, the limitations of these approaches are addressed, and potential avenues for future developments are explored.

Copper homeostasis dysregulation in respiratory diseases: a review of current knowledge

Cu is an essential micronutrient for various physiological processes in almost all human cell types. Given the critical role of Cu in a wide range of cellular processes, the local concentrations of Cu and the cellular distribution of Cu transporter proteins in the lung are essential for maintaining a steady-state internal environment. Dysfunctional Cu metabolism or regulatory pathways can lead to an imbalance in Cu homeostasis in the lungs, affecting both acute and chronic pathological processes. Recent studies have identified a new form of Cu-dependent cell death called cuproptosis, which has generated renewed interest in the role of Cu homeostasis in diseases. Cuproptosis differs from other known cell death pathways. This occurs through the direct binding of Cu ions to lipoylated components of the tricarboxylic acid cycle during mitochondrial respiration, leading to the aggregation of lipoylated proteins and the subsequent downregulation of Fe-S cluster proteins, which causes toxic stress to the proteins and ultimately leads to cell death. Here, we discuss the impact of dysregulated Cu homeostasis on the pathogenesis of various respiratory diseases, including asthma, chronic obstructive pulmonary disease, idiopathic interstitial fibrosis, and lung cancer. We also discuss the therapeutic potential of targeting Cu. This study highlights the intricate interplay between copper, cellular processes, and respiratory health. Copper, while essential, must be carefully regulated to maintain the delicate balance between necessity and toxicity in living organisms. This review highlights the need to further investigate the precise mechanisms of copper interactions with infections and immune inflammation in the context of respiratory diseases and explore the potential of therapeutic strategies for copper, cuproptosis, and other related effects.

Cuproptosis in lung cancer: therapeutic options and prognostic models

Lung cancer (LC) is a serious threat to mankind. The survival of LC patients is still poor despite the enormous efforts that have been made to develop novel treatments. A copper-dependent cell death termed cuproptosis is distinct from known programmed cell death (PCD). Cuproptosis is induced by the disruption of the binding of copper to lipoylated tricarboxylic acid (TCA) cycle proteins of mitochondrial respiratory chains. Potential approaches for treating LC are inducing cell cuproptosis and targeting cell copper death mechanisms. Thus, in this review, we summarize the systemic and cellular metabolic processes of copper. We highlight the possible therapeutic options of employing copper ionophores and chelators for inducing cuproptosis. Moreover, we summarize the prognostic models based on cuproptosis-related genes (CRGs) to identify promising biomarkers for tumor diagnosis and therapy. This review aims to provide a comprehensive summary of CRGs-based prognostic models and promising therapeutic options for cuproptosis induction in LC.

Dendritic Pyridine-Imine Copper Complexes as Metallo-Drugs

Since the discovery of cisplatin in the 1960s, the search for metallo-drugs that are more efficient than platinum complexes with negligible side effects has attracted much interest. Among the other metals that have been examined for potential applications as anticancer agents is copper. The interest in copper was recently boosted by the discovery of cuproptosis, a recently evidenced form of cell death mediated by copper. However, copper is also known to induce the proliferation of cancer cells. In view of these contradictory results, there is a need to find the most suitable copper chelators, among which Schiff-based derivatives offer a wide range of possibilities. Gathering several metal complexes in a single, larger entity may provide enhanced properties. Among the nanometric objects suitable for such purpose are dendrimers, precisely engineered hyperbranched macromolecules, which are outstanding candidates for improving therapy and diagnosis. In this review article, we present an overview of the use of a particular Schiff base, namely pyridine-imine, linked to the surface of dendrimers, suitable for complexing copper, and the use of such dendrimer complexes in biology, in particular against cancers.

Revealing the potential of solute carrier family 31 (copper transporters), member 1: Insights into its role in bladder cancer progression and therapeutic implications

Introduction: Bladder cancer represents a significant public health concern with diverse genetic alterations influencing disease onset, progression, and therapy response. In this study, we explore the multifaceted role of Solute Carrier Family 31 Member 1 (SLC31A1) in bladder cancer, a pivotal gene involved in copper homeostasis. Methods: Our research involved analyzing the SLC31A1 gene expression via RT-qPCR, promoter methylation via targeted bisulfite sequencing, and mutational status via Next Generation Sequencing (NGS) using the clinical samples sourced by the local bladder cancer patients. Later on, The Cancer Genome Atlas (TCGA) datasets were utilized for validation purposes. Moreover, prognostic significance, gene enrichment terms, and therapeutic drugs of SLC31A1 were also explored using KM Plotter, DAVID, and DrugBank databases. Results: We observed that SLC31A1 was significantly up-regulated at both the mRNA and protein levels in bladder cancer tissue samples, suggesting its potential involvement in bladder cancer development and progression. Furthermore, our investigation into the methylation status revealed that SLC31A1 was significantly hypomethylated in bladder cancer tissues, which may contribute to its overexpression. The ROC analysis of the SLC31A1 gene indicated promising diagnostic potential, emphasizing its relevance in distinguishing bladder cancer patients from normal individuals. However, it is crucial to consider other factors such as cancer stage, metastasis, and recurrence for a more accurate evaluation in the clinical context. Interestingly, mutational analysis of SLC31A1 demonstrated only benign mutations, indicating their unknown role in the SLC31A1 disruption. In addition to its diagnostic value, high SLC31A1 expression was associated with poorer overall survival (OS) in bladder cancer patients, shedding light on its prognostic relevance. Gene enrichment analysis indicated that SLC31A1 could influence metabolic and copper-related processes, further underscoring its role in bladder cancer. Lastly, we explored the DrugBank database to identify potential therapeutic agents capable of reducing SLC31A1 expression. Our findings unveiled six important drugs with the potential to target SLC31A1 as a treatment strategy. Conclusion: Our comprehensive investigation highlights SLC31A1 as a promising biomarker for bladder cancer development, progression, and therapy.

Docking Studies, Cytotoxicity Evaluation and Interactions of Binuclear Copper(II) Complexes with S-Isoalkyl Derivatives of Thiosalicylic Acid with Some Relevant Biomolecules

The numerous side effects of platinum based chemotherapy has led to the design of new therapeutics with platinum replaced by another transition metal. Here, we investigated the interactions of previously reported copper(II) complexes containing S-isoalkyl derivatives, the salicylic acid with guanosine-5'-monophosphate and calf thymus DNA (CT-DNA) and their antitumor effects, in a colon carcinoma model. All three copper(II) complexes exhibited an affinity for binding to CT-DNA, but there was no indication of intercalation or the displacement of ethidium bromide. Molecular docking studies revealed a significant affinity of the complexes for binding to the minor groove of B-form DNA, which coincided with DNA elongation, and a higher affinity for binding to Z-form DNA, supporting the hypothesis that the complex binding to CT-DNA induces a local transition from B-form to Z-form DNA. These complexes show a moderate, but selective cytotoxic effect toward colon cancer cells in vitro. Binuclear complex of copper(II) with S-isoamyl derivative of thiosalicylic acid showed the highest cytotoxic effect, arrested tumor cells in the G2/M phase of the cell cycle, and significantly reduced the expression of inflammatory molecules pro-IL-1β, TNF-α, ICAM-1, and VCAM-1 in the tissue of primary heterotopic murine colon cancer, which was accompanied by a significantly reduced tumor growth and metastases in the lung and liver.

Intelligent gold nanoparticles for malignant tumor treatment via spontaneous copper manipulation and on-demand photothermal therapy based on copper induced click chemistry

The excessive copper in tumor cells is crucial for the growth and metastasis of malignant tumor. Herein, we fabricated a nanohybrid to capture, convert and utilize the overexpressed copper in tumor cells, which was expected to achieve copper dependent photothermal damage of primary tumor and copper-deficiency induced metastasis inhibition, generating accurate and effective tumor treatment. The nanohybrid consistsed of 3-azidopropylamine, 4-ethynylaniline and N-aminoethyl-N'-benzoylthiourea (BTU) co-modified gold nanoparticles (AuNPs). During therapy, the BTU segment would specifically chelate with copper in tumor cells after endocytosis to reduce the intracellular copper content, causing copper-deficiency to inhibit the vascularization and tumor migration. Meanwhile, the copper was also rapidly converted to be cuprous by BTU, which further catalyzed the click reaction between azido and alkynyl on the surface of AuNPs, resulting in on-demand aggregation of these AuNPs. This process not only in situ generated the photothermal agent in tumor cells to achieve accurate therapy avoiding unexpected damage, but also enhanced its retention time for sustained photothermal therapy. Both in vitro and in vivo results exhibited the strong tumor inhibition and high survival rate of tumor-bearing mice after application of our nanohybrid, indicating that this synergistic therapy could offer a promising approach for malignant tumor treatment. STATEMENT OF SIGNIFICANCE: The distinctive excessive copper in tumor cells is crucial for the growth and metastasis of tumor. Therefore, we fabricated intelligent gold nanoparticles to simultaneously response and reverse this tumorigenic physiological microenvironment for the synergistic therapy of malignant tumor. In this study, for the first time we converted and utilized the overexpressed Cu2+ in tumor cells to trigger intracellular click chemistry for tumor-specific photothermal therapy, resulting in accurate damage of primary tumor. Moreover, we effectively manipulated the content of Cu2+ in tumor cells to suppress the migration and vascularization of malignant tumor, resulting in effective metastasis inhibition.

Targeting copper metabolism: a promising strategy for cancer treatment

Copper is an essential micronutrient that plays a critical role in many physiological processes. However, excessive copper accumulation in cancer cells has been linked to tumor growth and metastasis. This review article explores the potential of targeting copper metabolism as a promising strategy for cancer treatment. Excessive copper accumulation in cancer cells has been associated with tumor growth and metastasis. By disrupting copper homeostasis in cancer cells and inducing cell death through copper-dependent mechanisms (cuproplasia and cuprotosis, respectively), therapies can be developed with improved efficacy and reduced side effects. The article discusses the role of copper in biological processes, such as angiogenesis, immune response, and redox homeostasis. Various approaches for targeting copper metabolism in cancer treatment are examined, including the use of copper-dependent enzymes, copper-based compounds, and cuprotosis-related genes or proteins. The review also explores strategies like copper chelation therapy and nanotechnology for targeted delivery of copper-targeting agents. By understanding the intricate network of cuprotosis and its interactions with the tumor microenvironment and immune system, new targets for therapy can be identified, leading to improved cancer treatment outcomes. Overall, this comprehensive review highlights the significant potential of targeting copper metabolism as a promising and effective approach in cancer treatment, while providing valuable insights into the current state of research in this field.

Surface Modification of Titanium Implants by Metal Ions and Nanoparticles for Biomedical Application

Implant surface modification can improve osseointegration and reduce peri-implant inflammation. Implant surfaces are modified with metals because of their excellent mechanical properties and significant functions. Metal surface modification is divided into metal ions and nanoparticle surface modification. These two methods function by adding a finishing metal to the surface of the implant, and both play a role in promoting osteogenic, angiogenic, and antibacterial properties. Based on this, the nanostructural surface changes confer stronger antibacterial and cellular affinity to the implant surface. The current paper reviews the forms, mechanisms, and applications of nanoparticles and metal ion modifications to provide a foundation for the surface modification of implants.

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).

Soy Isoflavones Induce Cell Death by Copper-Mediated Mechanism: Understanding Its Anticancer Properties

Cancer incidence varies around the globe, implying a relationship between food and cancer risk. Plant polyphenols are a class of secondary metabolites that have recently attracted attention as possible anticancer agents. The subclass of polyphenols, known as isoflavones, includes genistein and daidzein, which are present in soybeans and are regarded as potent chemopreventive agents. According to epidemiological studies, those who eat soy have a lower risk of developing certain cancers. Several mechanisms for the anticancer effects of isoflavones have been proposed, but none are conclusive. We show that isoflavones suppress prostate cancer cell growth by mobilizing endogenous copper. The copper-specific chelator neocuproine decreases the apoptotic potential of isoflavones, whereas the iron and zinc chelators desferroxamine mesylate and histidine do not, confirming the role of copper. Reactive oxygen species (ROS) scavengers reduce isoflavone-induced apoptosis in these cells, implying that ROS are cell death effectors. Our research also clearly shows that isoflavones interfere with the expression of the two copper transporter genes, CTR1 and ATP7A, in cancerous cells. Copper levels are widely known to be significantly raised in all malignancies, and we confirm that isoflavones can target endogenous copper, causing prooxidant signaling and, eventually, cell death. These results highlight the importance of copper dynamics within cancer cells and provide new insight into the potential of isoflavones as cancer-fighting nutraceuticals.

Potential of Copper and Copper Compounds for Anticancer Applications

Inducing cancer cell death has always been a research hotspot in life sciences. With the continuous deepening and diversification of related research, the potential value of metal elements in inducing cell death has been explored. Taking iron as an example, ferroptosis, mainly characterized by increasing iron load and driving the production of large amounts of lipid peroxides and eventually leading to cell death, has recently attracted great interest in the cancer research community. After iron, copper, a trace element, has received extensive attention in cell death, especially in inducing tumor cell death. Copper and its complexes can induce autophagy or apoptosis in tumor cells through a variety of different mechanisms of action (activation of stress pathways, arrest of cell cycle, inhibition of angiogenesis, cuproptosis, and paraptosis), which are promising in cancer therapy and have become new hotspots in cancer treatment research. This article reviews the main mechanisms and potential applications of novel copper and copper compound-induced cell death, focusing on copper compounds and their anticancer applications.

Dinuclear doubly bridged phenoxido copper(II) complexes as efficient anticancer agents

Two cationic [Cu₂(L^1-2)₂](ClO₄)₂ (1, 2), and four neutral doubly bridged-phenoxido-copper(II) complexes [Cu₂(L^3-4)₂] (3, 4) and [Cu₂(L^5-6)₂(H₂O)]‧2H₂O (5, 6) as well as 1D polymeric catena-[Cu(L⁷)] (7), where HL^1-2 and H₂L^3-7 represent tripodal tetradentate pyridyl or aliphatic-amino groups based 2,4-disubstituted phenolates, were synthesized and thoroughly characterized by various spectroscopic methods and single crystal X-ray analysis. The molecular structures of the complexes exhibited diverse geometrical environments around the central Cu(II) atoms. The in vitro antiproliferative activity of the isolated complexes and selected parent free ligands were screened against some human cancer cell lines (A2780, A2780R, PC-3, 22Rv1, MCF-7). The most promising cytotoxicity against cancer cells were obtained for 1-6, while complex 6 was found as the best performing as compared to the reference drug cisplatin. The cytotoxicity study of complex 6 was therefore extended to wider variety of cancer cell lines (HOS, A549, PANC-1, CaCo2, HeLa) and results revealed its significant cytotoxicity on all investigated human cancer cells. The cell uptake study showed that cytotoxicity of 6 (3 μM concentration and 24 h of incubation) against A2780 cells was almost independent from the intracellular levels of copper. The effect of complexes 4, 6 and 7 on cell cycle of A2780 cells indicates that the mechanism of action in these complexes is not only different from that of cisplatin but also different among them. Complex 7 was able to induce apoptosis in A2780 cells, while complexes 4 and 6 did not and on the other hand, they showed considerable effect on autophagy induction and there are some clues that these complexes were able to induce cuproptosis in A2780 cells.

Crystal structure, in vitro cytotoxicity, DNA binding and DFT calculations of new copper (II) complexes with coumarin-amide ligand

This work describes the synthesis, anticancer activity and electron structure study of two Cu (II) complexes with coumarin-3-formyl-(3-(aminomethyl) pyridine) ligand (L) - C1 (Cu₂L₂(OAc)₄) and C2 (CuL₂(NO₃)₂). The structure of C1 and C2 was confirmed by elemental analysis, FTIR, and single-crystal X-ray analysis. Complex C1 crystallizes as binuclear where two Cu (II) ions are bridged by four acetate ligands while C2 is a mononuclear complex with twisted octahedral geometry. Density functional theory (DFT) calculations revealed that electronic transitions originate from metal-ligand charge transfer and d-d transitions of metal ions. According to the results of UV-Vis and fluorescence titrations, C1 and C2 intercalate with DNA with the binding constants of 6.9 × 10⁵ M^-1 and 5.9 × 10⁵ M^-1, respectively. The in vitro cytotoxicity assays on four cancer cell lines (HeLa, HepG2, MCF-7 and A549) and a normal HUVEC cell line indicated higher anti-MCF-7 activity of C2 compared with cisplatin (IC₅₀ = 2.86 ± 0.08 μM vs. 9.07 ± 0.10 μM). Moreover, C2 had superior selectivity since IC₅₀ toward HUVEC cells was over 150 μM compared with 0.58 ± 0.05 μM for cisplatin. We concluded that the anti-MCF activity of mononuclear C2 complex is better than that of binuclear C1 and cisplatin. Therefore, C2 has been selected as a hit compound to develop novel non‑platinum anticancer agents through modification of coumarin-amide structure and variation of copper (II) salts.

Radiation Type- and Dose-Specific Transcriptional Responses across Healthy and Diseased Mammalian Tissues

Ionizing radiation (IR) is a genuine genotoxic agent and a major modality in cancer treatment. IR disrupts DNA sequences and exerts mutagenic and/or cytotoxic properties that not only alter critical cellular functions but also impact tissues proximal and distal to the irradiated site. Unveiling the molecular events governing the diverse effects of IR at the cellular and organismal levels is relevant for both radiotherapy and radiation protection. Herein, we address changes in the expression of mammalian genes induced after the exposure of a wide range of tissues to various radiation types with distinct biophysical characteristics. First, we constructed a publicly available database, termed RadBioBase, which will be updated at regular intervals. RadBioBase includes comprehensive transcriptomes of mammalian cells across healthy and diseased tissues that respond to a range of radiation types and doses. Pertinent information was derived from a hybrid analysis based on stringent literature mining and transcriptomic studies. An integrative bioinformatics methodology, including functional enrichment analysis and machine learning techniques, was employed to unveil the characteristic biological pathways related to specific radiation types and their association with various diseases. We found that the effects of high linear energy transfer (LET) radiation on cell transcriptomes significantly differ from those caused by low LET and are consistent with immunomodulation, inflammation, oxidative stress responses and cell death. The transcriptome changes also depend on the dose since low doses up to 0.5 Gy are related with cytokine cascades, while higher doses with ROS metabolism. We additionally identified distinct gene signatures for different types of radiation. Overall, our data suggest that different radiation types and doses can trigger distinct trajectories of cell-intrinsic and cell-extrinsic pathways that hold promise to be manipulated toward improving radiotherapy efficiency and reducing systemic radiotoxicities.

A transcriptome-wide association study of uterine fibroids to identify potential genetic markers and toxic chemicals

Uterine fibroid is one of the most prevalent benign tumors in women, with high socioeconomic costs. Although genome-wide association studies (GWAS) have identified several loci associated with uterine fibroid risks, they could not successfully interpret the biological effects of genomic variants at the gene expression levels. To prioritize uterine fibroid susceptibility genes that are biologically interpretable, we conducted a transcriptome-wide association study (TWAS) by integrating GWAS data of uterine fibroid and expression quantitative loci data. We identified nine significant TWAS genes including two novel genes, RP11-282O18.3 and KBTBD7, which may be causal genes for uterine fibroid. We conducted functional enrichment network analyses using the TWAS results to investigate the biological pathways in which the overall TWAS genes were involved. The results demonstrated the immune system process to be a key pathway in uterine fibroid pathogenesis. Finally, we carried out chemical–gene interaction analyses using the TWAS results and the comparative toxicogenomics database to determine the potential risk chemicals for uterine fibroid. We identified five toxic chemicals that were significantly associated with uterine fibroid TWAS genes, suggesting that they may be implicated in the pathogenesis of uterine fibroid. In this study, we performed an integrative analysis covering the broad application of bioinformatics approaches. Our study may provide a deeper understanding of uterine fibroid etiologies and informative notifications about potential risk chemicals for uterine fibroid.

Poly(methacrylate citric acid) as a Dual Functional Carrier for Tumor Therapy

Owing to its pH-sensitive property and chelating Cu²⁺ effect, poly(methacrylate citric acid) (PCA) can be utilized as a dual functional nanocarrier to construct a nanodelivery system. Negatively charged carboxyl groups can interact with positively charged antineoplastic drugs through electrostatic interaction to form stable drug nanoparticles (NPs). Through drug experimental screening, doxorubicin (DOX) was selected as the model drug, PCA/DOX NPs with a diameter of 84 nm were prepared, and the drug-loading content was 68.3%. PCA/DOX NPs maintained good stability and a sustained release profile. Cell experiments presented that PCA/DOX NPs could inhibit effectively the growth of 4T1 cells; the IC₅₀ value was decreased by approximately 15-fold after incubation for 72 h. The cytotoxicity toward H9C2 was decreased significantly. Moreover, based on its ability to efficiently adsorb copper ions, PCA showed good vascular growth inhibition effect in vitro. Furthermore, animal experiments showed that PCA/DOX NPs presented stronger anticancer effects than DOX; the tumor inhibition rate was increased by 1.5-fold. Myocardial toxicity experiments also confirmed that PCA reduced the cardiotoxicity of DOX. In summary, PCA/DOX NPs show good antitumor efficacy and low toxicity, and have good potential for clinical application.

Synthesis, X-ray Structure and Biological Studies of New Self-Assembled Cu(II) Complexes Derived from s-triazine Schiff Base Ligand

The two ligands 2-(1-(2-(4,6-dimorpholino-1,3,5-triazin-2-yl)hydrazono)ethyl)aniline (DMAT) and 2-(1-(2-(4,6-dimorpholino-1,3,5-triazin-2-yl)hydrazono)ethyl)phenol (DMOHT) were used to synthesize three heteroleptic Cu(II) complexes via a self-assembly technique. The structure of the newly synthesized complexes was characterized using elemental analysis, FTIR and X-ray photoelectron spectroscopy (XPS) to be [Cu(DMAT)(H2O)(NO3)]NO3.C2H5OH (1), [Cu(DMOT)(CH3COO)] (2) and [Cu(DMOT)(NO3)] (3). X-ray single-crystal structure of complex 1 revealed a hexa-coordinated Cu(II) ion with one DMAT as a neutral tridentate NNN-chelate, one bidentate nitrate group and one water molecule. In the case of complex 2, the Cu(II) is tetra-coordinated with one DMOT as an anionic tridentate NNO-chelate and one monodentate acetate group. The antimicrobial, antioxidant and anticancer activities of the studied compounds were examined. Complex 1 had the best anticancer activity against the lung carcinoma A-549 cell line (IC50 = 5.94 ± 0.58 µM) when compared to cis-platin (25.01 ± 2.29 µM). The selectivity index (SI) of complex 1 was the highest (6.34) when compared with the free ligands (1.3–1.8), and complexes 2 (0.72) and 3 (2.97). The results suggested that, among those compounds studied, complex 1 is the most promising anticancer agent against the lung carcinoma A-549 cell line. In addition, complex 1 had the highest antioxidant activity (IC50 = 13.34 ± 0.58 µg/mL) which was found to be comparable to the standard ascorbic acid (IC50 = 10.62 ± 0.84 µg/mL). Additionally, complex 2 showedbroad-spectrum antimicrobial action against the microbes studied. The results revealed it to possess the strongest action of all the three complexes against B. subtilis. The MIC values found are 39.06, 39.06 and 78.125 mg/mL for complexes 1–3, respectively.

Relevance of Fluorinated Ligands to the Design of Metallodrugs for Their Potential Use in Cancer Treatment

Fluorination of pharmaceutical agents has afforded crucial modifications to their pharmacological profiles, leading to important advances in medicinal chemistry. On the other hand, metallodrugs are considered to be valuable candidates in the treatment of several diseases, albeit with the caveat that they may exhibit pharmacological disadvantages, such as poor water solubility, low bioavailability and short circulating time. To surmount these limitations, two approaches have been developed: one based on the design of novel metallodrug-delivering carriers and the other based on optimizing the structure of the ligands bound to the metal center. In this context, fluorination of the ligands may bring beneficial changes (physicochemical and biological) that can help to elude the aforementioned drawbacks. Thus, in this review, we discuss the use of fluorinated ligands in the design of metallodrugs that may exhibit potential anticancer activity.

Multivariate Investigation of Toxic and Essential Metals in the Serum from Various Types and Stages of Colorectal Cancer Patients

Colorectal cancer (CRC) is currently one of the most frequent malignant neoplasms, ranking 3rd in incidence and 2nd in mortality both in the USA and across the world. The pathogenesis of CRC is a complex interaction between genetic susceptibility and environmental factors such as exposure to metals. Therefore, the present study was intended to assess the imbalances in the concentrations of selected essential/toxic elements (Pb, Cr, Fe, Zn, As, Cd, Cu, Se, Ni, and Hg) in the serum of newly diagnosed colorectal carcinoma patients (n = 165) in comparison with counterpart controls (n = 151) by atomic absorption spectrometry after wet-acid digestion method. Serum carcinoembryonic antigen (CEA) of the CRC patients was determined using immunoradiometric method. Body mass index (BMI) which is an established risk factor for CRC was also calculated for patients and healthy controls. Conversely, average Ni (2.721 μg/g), Cd (0.563 μg/g), As (0.539 μg/g), and Pb (1.273 μg/g) levels were significantly elevated in the serum of CRC patients compared to the healthy donors, while the average Se (7.052 μg/g), Fe (15.67 μg/g), Cu (2.033 μg/g), and Zn (8.059 μg/g) concentrations were elevated in controls. The correlation coefficients between the elements in the cancerous patients demonstrated significantly dissimilar communal relationships compared with the healthy subjects. Significant differences in the elemental levels were also showed for CRC types (primary colorectal lymphoma, gastrointestinal stromal tumor, and adenocarcinoma) and CRC stages (stage-I, stage-II, stage-III, and stage-IV) among the patients. Majority of the elements demonstrated perceptible disparities in their levels based on dietary, habitat, gender, and smoking habits of the malignant patients and healthy subjects. Multivariate methods revealed noticeably divergent apportionment among the toxic/essential elements in the cancerous patients than the healthy counterparts. Overall, the study showed significantly divergent distribution and associations of the essential and toxic elemental levels in the serum of the CRC patients in comparison with the healthy donors.

Synthesis, DNA-binding abilities, and in vitro antitumor activity of water-soluble copper porphyrin and its Schiff-base complexes

Three new water-soluble porphyrin Cu(ii)-complexes (CuP-1, CuP-2, and CuP-3) were prepared and characterized, which had the ability to bind ct-DNA and good cytotoxicity. CuP-1 showed the best antiproliferative activity towards TCA8113 cells.

Concentration of heavy metals and rare earth elements in patients with brain tumours: Analysis in tumour tissue, non-tumour tissue, and blood

Inorganic elements have been associated with brain tumours for long. The blood concentration of 47 elements was assessed by ICP-MS in 26 brain tumour patients and 21 healthy subjects from Bucharest (Romania). All 47 elements were detected in the brain tumour tissue, and 22 were detected in > 80% of samples; this implies that these elements can cross the blood-brain barrier. Median blood levels of cadmium, lead, and nickel were higher than the reference values (1.14, 53.3, and 2.53 ng/mL). Gadolinium and tantalum showed significantly higher concentrations among cases. We observed considerable differences and different profiles of the presence of inorganic elements between the tumour and non-tumour brain tissue and between tissue from the primary tumour and tissue from brain metastasis. Our data suggest that similar to heavy metals, other elements - commonly used in high tech devices and rare earth elements - can also influence brain tumour.

Copper uptake in adult rainbow trout irradiated during early life stages and in non-irradiated bystander trout which swam with the irradiated fish

PURPOSE

This investigation forms part of a wider study into the legacy effects of exposure of rainbow trout eggs 38 h after fertilization, eyed eggs, yolk sac larvae (YSL) or first feeders to a single 0.5 Gy X-ray dose, including the induction of a bystander effect, by the irradiated fish, to non-irradiated fish. Fish may be exposed to multiple environmental stressors, including waterborne metals, during their lifespan and, while there are data on how the legacy of early life stage irradiation and bystander effect induction is affected by waterborne aluminum and cadmium, there are no studies into the effects radiation or the radiation induced bystander effect on metal uptake. Therefore the aim of this investigation was to determine if the legacy of early life stage irradiation included an effect on copper uptake by adult fish and by non-irradiated bystander adult trout which swam with the irradiated fish.

METHODS

The four early life stages mentioned above were exposed to a single 0.5 Gy X-ray dose and then maintained, for two years with no further irradiation. At two years old the irradiated fish were allowed to swim, for 2 h with non-irradiated bystander trout (also two years old). After this time copper uptake was determined using ⁶⁴Cu.

RESULTS

Copper uptake was increased in adult trout irradiated as eggs at 48 h after fertilization and as first feeders but eyed egg or YSL irradiation had no effect. Copper uptake was also increased in the bystander trout which swam with trout irradiated as eggs at 48 h after fertilization and as eyed eggs but there was no effect on non-irradiated adult trout which swam with trout irradiated as YSL or first feeders.

CONCLUSIONS

When put in context with the proteomic changes observed in these fish we propose the increased copper uptake in adult trout irradiated as eggs at 48 h after fertilization could be part of an anti-tumorigenic response and the increase in copper uptake in adult trout irradiated as first feeders could be part of a potentially protective pro-apoptotic response. Similarly we propose the increase in copper uptake in non-irradiated adult trout, induced by trout irradiated as eggs at 48 h after fertilization or as eyed eggs, was part of the universally anti-tumorigenic nature of the X-ray induced bystander effect in fish. However this was exclusive to embryonic irradiation.

Role of Copper on Mitochondrial Function and Metabolism

Copper is essential for life processes like energy metabolism, reactive oxygen species detoxification, iron uptake, and signaling in eukaryotic organisms. Mitochondria gather copper for the assembly of cuproenzymes such as the respiratory complex IV, cytochrome c oxidase, and the antioxidant enzyme superoxide dismutase 1. In this regard, copper plays a role in mitochondrial function and signaling involving bioenergetics, dynamics, and mitophagy, which affect cell fate by means of metabolic reprogramming. In mammals, copper homeostasis is tightly regulated by the liver. However, cellular copper levels are tissue specific. Copper imbalances, either overload or deficiency, have been associated with many diseases, including anemia, neutropenia, and thrombocytopenia, as well as tumor development and cancer aggressivity. Consistently, new pharmacological developments have been addressed to reduce or exacerbate copper levels as potential cancer therapies. This review goes over the copper source, distribution, cellular uptake, and its role in mitochondrial function, metabolic reprograming, and cancer biology, linking copper metabolism with the field of regenerative medicine and cancer.

Plasma metals and cancer incidence in patients with type 2 diabetes

There is limited evidence on the relationships between plasma levels of multiple metals and risk of incident cancer in patients with type 2 diabetes mellitus (T2DM). We examined the associations between plasma levels of 12 metals (iron, copper, zinc, selenium, chromium, manganese, molybdenum, cobalt, nickel, arsenic, cadmium, and lead) and cancer risk in 4573 T2DM patients using Cox proportional hazards models. With a median follow-up of 10.2 years, 541 incident cancers were identified. The multiple-metals model revealed that each 1-SD increase in ln-transformed plasma copper (HR: 1.14; 95%CI: 1.02, 1.27) and lead (HR:1.20; 95%CI:1.03, 1.39) were significantly associated with increased cancer incidence while each 1-SD increase in ln-transformed plasma zinc (HR: 0.82; 95%CI: 0.71, 0.96) and chromium (HR: 0.88; 95%CI: 0.82, 0.94) were significantly associated with decreased cancer incidence. When all participants were further stratified into four subgroups by the quartile levels (Q1-4) of plasma metals, manganese showed significant positive associations with cancer incidence in the upper two quartiles (P trend = 0.003) while nickel showed significant negative associations with cancer incidence in Q2 and 4 groups (P trend = 0.033) compared with participants in Q1 group. Collectively, monitoring of metal levels in diabetic patients needs to be strengthened, which is of great significance for the prevention of incident cancer.

Characterization of graphene/pine wood biochar hybrids: Potential to remove aqueous Cu2

Biochar-based hybrid composites containing added nano-sized phases are emerging adsorbents. Biochar, when functionalized with nanomaterials, can enhance pollutant removal when both the nanophase and the biochar surface act as adsorbents. Three different pine wood wastes (particle size < 0.5 mm, 10 g) were preblended with 1 wt% of three different graphenes in aqueous suspensions, designated as G1, G2, and G3. G1 (S_BET, 8.1 m²/g) was prepared by sonicating graphite made from commercial synthetic graphite powder (particle size 7-11 μm). G2 (312.0 m²/g) and G3 (712.0 m²/g) were purchased commercial graphene nanoplatelets (100 mg in 100 mL deionized water). These three pine wood-graphene mixtures were pyrolyzed at 600 °C for 1 h to generate three graphene-biochar adsorbents, GPBC-1, GPBC-2, and GPBC-3 containing 4.4, 4.9, and 5.0 wt% of G1, G2, and G3 respectively. Aqueous Cu²⁺ adsorption capacities were 10.6 mg/g (GPBC-1), 4.7 mg/g (GPBC-2), and 5.5 mg/g (GPBC-3) versus 7.2 mg/g for raw pine wood biochar (PBC) (0.05 g adsorbent dose, Cu²⁺ 75 mg/L, 25 mL, pH 6, 24 h, 25 ± 0.5 °C). Increased graphene surface areas did not result in adsorption increases. GPBC-1, containing the lowest nanophase surface area with the highest Cu²⁺ capacity, was chosen to evaluate its Cu²⁺ adsorption characteristics further. Results from XPS showed that the surface concentration of oxygenated functional groups on the GPBC-1 is greater than that on the PBC, possibly contributing to its greater Cu²⁺ removal versus PBC. GPBC-1 and PBC uptake of Cu²⁺ followed the pseudo-second-order kinetic model. Langmuir maximum adsorption capacities and BET surface areas were 18.4 mg/g, 484.0 m²/g (GPBC-1) and 9.2 mg/g, 378.0 m²/g (PBC). This corresponds to 3.8 × 10^-2 versus 2.4 × 10^-2 mg/m² of Cu²⁺ removed on GPBC-1 (58% more Cu²⁺ per m²) versus PBC. Cu²⁺ adsorption on both these adsorbents was spontaneous and endothermic.

Opportunities for plant-derived enhancers for iron, zinc, and calcium bioavailability: A review

Understanding of the mechanism of interactions between dietary elements, their salts, and complexing/binding ligands is vital to manage both deficiency and toxicity associated with essential element bioavailability. Numerous mineral ligands are found in both animal and plant foods and are known to exert bioactivity via element chelation resulting in modulation of antioxidant capacity or micobiome metabolism among other physiological outcomes. However, little is explored in the context of dietary mineral ligands and element bioavailability enhancement, particularly with respect to ligands from plant-derived food sources. This review highlights a novel perspective to consider various plant macro/micronutrients as prospective bioavailability enhancing ligands of three essential elements (Fe, Zn, and Ca). We also delineate the molecular mechanisms of the ligand-binding interactions underlying mineral bioaccessibility at the luminal level. We conclude that despite current understandings of some of the structure-activity relationships associated with strong mineral-ligand binding, the physiological links between ligands as element carriers and uptake at targeted sites throughout the gastrointestinal (GI) tract still require more research. The binding behavior of potential ligands in the human diet should be further elucidated and validated using pharmacokinetic approaches and GI models.

Mechanism of cystathionine-β-synthase inhibition by disulfiram: The role of bis(N,N-diethyldithiocarbamate)-copper(II)

BACKGROUND

Hydrogen sulfide (H₂S) is an endogenous mammalian gasotransmitter. Cystathionine β-synthase (CBS), cystathionine γ-lyase (CSE) and 3-mercaptopyruvate sulfurtransferase (3-MST) are the principal enzymes responsible for its biogenesis. A recent yeast screen suggested that disulfiram (a well-known inhibitor of aldehyde dehydrogenase and a clinically used drug in the treatment of alcoholism) may inhibit CBS in a cell-based environment. However, prior studies have not observed any direct inhibition of CBS by disulfiram. We investigated the potential role of bioconversion of disulfiram to bis(N,N-diethyldithiocarbamate)-copper(II) complex (CuDDC) in the inhibitory effect of disulfiram on H₂S production and assessed its effect in two human cell types with high CBS expression: HCT116 colon cancer cells and Down syndrome (DS) fibroblasts.

METHODS

H₂S production from recombinant human CBS, CSE and 3-MST was measured using the fluorescent H₂S probe AzMC. Mouse liver homogenate (a rich source of CBS) was also employed to measure H₂S biosynthesis. The interaction of copper with accessible protein cysteine residues was evaluated using the DTNB method. Cell proliferation and viability were measured using the BrdU and MTT methods. Cellular bioenergetics was evaluated by Extracellular Flux Analysis.

RESULTS

While disulfiram did not exert any significant direct inhibitory effect on any of the H₂S-producing enzymes, its metabolite, CuDDC was a potent inhibitor of CBS and CSE. The mode of its action is likely related to the complexed copper molecule. In cell-based systems, the effects of disulfiram were variable. In colon cancer cells, no significant effect of disulfiram was observed on H₂S production or proliferation or viability. In contrast, in DS fibroblasts, disulfiram inhibited H₂S production and improved proliferation and viability. Copper, on its own, failed to have any effects on either cell type, likely due to its low cell penetration. CuDDC inhibited H₂S production in both cell types studied and exerted the functional effects that would be expected from a CBS inhibitor: inhibition of cell proliferation of cancer cells and a bell-shaped effect (stimulation of proliferation at low concentration and inhibition of these responses at higher concentration) in DS cells. Control experiments using a chemical H₂S donor showed that, in addition to inhibiting CBS and CSE, part of the biological effects of CuDDC relates to a direct reaction with H₂S, which occurs through its complexed copper.

CONCLUSIONS

Disulfiram, via its metabolite CuDDC acts as an inhibitor of CBS and a scavenger of H₂S, which, in turn, potently suppresses H₂S levels in various cell types. Inhibition of H₂S biosynthesis may explain some of the previously reported actions of disulfiram and CuDDC in vitro and in vivo. Disulfiram or CuDDC may be considered as potential agents for the experimental therapy of various pathophysiological conditions associated with H₂S overproduction.

Copper Complexes as Anticancer Agents Targeting Topoisomerases I and II

Organometallics, such as copper compounds, are cancer chemotherapeutics used alone or in combination with other drugs. One small group of copper complexes exerts an effective inhibitory action on topoisomerases, which participate in the regulation of DNA topology. Copper complexes inhibitors of topoisomerases 1 and 2 work by different molecular mechanisms, analyzed herein. They allow genesis of DNA breaks after the formation of a ternary complex, or act in a catalytic mode, often display DNA intercalative properties and ROS production, and sometimes display dual effects. These amplified actions have repercussions on the cell cycle checkpoints and death effectors. Copper complexes of topoisomerase inhibitors are analyzed in a broader synthetic view and in the context of cancer cell mutations. Finally, new emerging treatment aspects are depicted to encourage the expansion of this family of highly active anticancer drugs and to expend their use in clinical trials and future cancer therapy.

The molecular mechanisms of copper metabolism and its roles in human diseases

Copper is an essential element in cells; it can act as either a recipient or a donor of electrons, participating in various reactions. However, an excess of copper ions in cells is detrimental as these copper ions can generate free radicals and increase oxidative stress. In multicellular organisms, copper metabolism involves uptake, distribution, sequestration, and excretion, at both the cellular and systemic levels. Mammalian enterocytes take in bioavailable copper ions from the diet in a Ctr1-dependent manner. After incorporation, cuprous ions are delivered to ATP7A, which pumps Cu⁺ from enterocytes into the blood. Copper ions arrive at the liver through the portal vein and are incorporated into hepatocytes by Ctr1. Then, Cu⁺ can be secreted into the bile or the blood via the Atox1/ATP7B/ceruloplasmin route. In the bloodstream, this micronutrient can reach peripheral tissues and is again incorporated by Ctr1. In peripheral tissue cells, cuprous ions are either sequestrated by molecules such as metallothioneins or targeted to utilization pathways by chaperons such as Atox1, Cox17, and CCS. Copper metabolism must be tightly controlled in order to achieve homeostasis and avoid disorders. A hereditary or acquired copper unbalance, including deficiency, overload, or misdistribution, may cause or aggravate certain diseases such as Menkes disease, Wilson disease, neurodegenerative diseases, anemia, metabolic syndrome, cardiovascular diseases, and cancer. A full understanding of copper metabolism and its roles in diseases underlies the identification of novel effective therapies for such diseases.

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.

Status of copper accumulation in agricultural soils across China (1985-2016)

The first national-scale assessment of Cu contamination of agricultural soils covering 1731 sites in China was performed based on 1837 published papers. The temporal and spatial variations from 1985 to 2016 in the Cu concentrations and the ecological and health risks associated with Cu exposure were analyzed. Approximately, 21.02% of the sampling sites revealed Cu concentrations that exceeded the screening value (50.00 mg/kg; GB15618-2018). The Cu concentrations differed among five geographical regions in the decreasing order of South China > West China > East China > Northeast China > North China. Notably, concentration of Cu in agricultural soils have begun to diminish since 2011 due to reduced heavy metal inputs. Cu mainly originated from anthropogenic activities such as mining and agricultural activities. Linear correlations were observed between the amounts of fungicides and fertilizers applied and the Cu concentrations in the soils, which suggested that the application of fungicides and fertilizers is an important contributor to the accumulation of Cu in soils. Additionally, the geoaccumulation index (I_geo) and ecological risk index (E_fⁱ) values implied that pollution and ecological risk resulting from soil Cu concentration were in low levels. The hazard index (HI) values were higher for children than for adults. Therefore, children should be prioritized for protection from heavy metal pollution. Overall, this study details the status of Cu contamination of agricultural soils in China, and thus provides insights for policymakers regarding the preventive measures.

A survey of trace metal burdens in increment cores from eastern cottonwood (Populus deltoides) across a childhood cancer cluster, Sandusky County, OH, USA

A dendrochemical study of cottonwood trees (Populus deltoides) was conducted across a childhood cancer cluster in eastern Sandusky County (Ohio, USA). The justification for this study was that no satisfactory explanation has yet been put forward, despite extensive local surveys of aerosols, groundwater, and soil. Concentrations of eight trace metals were measured by ICP-MS in microwave-digested 5-year sections of increment cores, collected during 2012 and 2013. To determine whether the onset of the first cancer cases could be connected to an emergence of any of these contaminants, cores spanning the period 1970-2009 were taken from 51 trees of similar age, inside the cluster and in a control area to the west. The abundance of metals in cottonwood tree annual rings served as a proxy for their long-term, low-level accumulation from the same sources whereby exposure of the children may have occurred. A spatial analysis of cumulative metal burdens (lifetime accumulation in the tree) was performed to search for significant 'hotspots', employing a scan statistic with a mask of variable radius and center. For Cd, Cr, and Ni, circular hotspots were found that nearly coincide with the cancer cluster and are similar in size. No hotspots were found for Co, Cu, and Pb, while As and V were largely below method detection limits. Whereas our results do not implicate exposure to metals as a causative factor, we conclude that, after 1970, cottonwood trees have accumulated more Cd, Cr, and Ni, inside the childhood cancer cluster than elsewhere in Sandusky County.

Structure elucidation {spectroscopic, single crystal X-ray diffraction and computational DFT studies} of new tailored benzenesulfonamide derived Schiff base copper(II) intercalating complexes: Comprehensive biological profile {DNA binding, pBR322 DNA cleavage, Topo I inhibition and cytotoxic activity}

New tailored copper(II)-based intercalating complexes [Cu(L1)2] (1) and [Cu(L2)2] (2) were synthesized from Schiff base scaffold HL1 and HL2(E)-4-(2-((2-hydroxy-3-methoxybenzylidene)amino)ethyl)benzenesulfonamide and (E)-4-(2-((2-hydroxybenzylidene)amino)ethyl)benzenesulfonamide, respectively. The structure elucidation of complexes 1 and 2 was carried out by employing various spectroscopic techniques viz., FT-IR, UV-vis, ESI-MS, EPR and single X-ray crystal diffraction studies. The complexes 1 and 2 were crystallized in monoclinic P21/n and triclinic P-1 space group, respectively possessing square planar geometry around Cu(II) coordinated with N,O-donor Schiff base ligands. An analysis of Hirshfeld surfaces of complexes 1 and 2 were performed to ascertain different intra and intermolecular non-covalent interactions (H-bonding, CH⋯ πetc.) responsible for the stabilization of crystal lattices. Calculations based on Density functional theory (B3LYP/DFT), have been carried out to obtain energies of Frontier molecular orbitals. Comparative in vitro binding profile of complexes 1 and 2 with ct-DNA was evaluated employing various biophysical techniques viz., UV-vis, fluorescence, circular dichroism and cyclic voltammetry which suggested non-covalent intercalative binding mode with more avid binding propensity of complex 1 compared to complex 2. The cleavage experiments of complex 1 was performed by gel electrophoretic assay which revealed efficient cleavage mediated via oxidative pathway. Furthermore, topoisomerase I enzymatic activity of complex 1 was carried out employing gel electrophoretic assay which demonstrated significant inhibitory effects at a low concentration of 25 µM. The cytotoxic potential of complex 1 was analyzed by SRB assay on a panel of selected human cancer cell lines which revealed selective activity for MCF-7 (breast cancer) cell line with GI50 = 16.21 µg/ml.

Triacontanoic ester of 5''-hydroxyjustisolin: Tumour suppressive role in cervical cancer via Bcl-2, BAX and caspase-3 mediated signalling

Triacontanoic ester of 5"-hydroxyjustisolin, a lignan from Justicia simplex D. Don, possesses antitumor activity. However, the molecular mechanism underlying this is not yet clearly understood. The present study showed significant inhibition in cell viability on HeLa cell line and induced minor toxicity in normal cells. This compound induced mitotic arrest at G0/G1 phase followed by apoptosis in human cervical cancer cells and was accompanied by the upregulation of BAX, caspase-3 and downregulation of Bcl-2. Taken together, these data reveal that the title compound acts through multiple cellular/molecular pathways, which strongly suggest the role of pro and antiapoptotic Bcl-2 family proteins. Triacontanoic ester of 5''-hydroxyjustisolin may be a potential agent for the cervical cancer treatment.

Nanoparticle-Based Nanomedicines to Promote Cancer Immunotherapy: Recent Advances and Future Directions

Cancer immunotherapy is a promising cancer terminator by directing the patient's own immune system in the fight against this challenging disorder. Despite the monumental therapeutic potential of several immunotherapy strategies in clinical applications, the efficacious responses of a wide range of immunotherapeutic agents are limited in virtue of their inadequate accumulation in the tumor tissue and fatal side effects. In the last decades, increasing evidences disclose that nanotechnology acts as an appealing solution to address these technical barriers via conferring rational physicochemical properties to nanomaterials. In this Review, an imperative emphasis will be drawn from the current understanding of the effect of a nanosystem's structure characteristics (e.g., size, shape, surface charge, elasticity) and its chemical modification on its transport and biodistribution behavior. Subsequently, rapid-moving advances of nanoparticle-based cancer immunotherapies are summarized from traditional vaccine strategies to recent novel approaches, including delivery of immunotherapeutics (such as whole cancer cell vaccines, immune checkpoint blockade, and immunogenic cell death) and engineered immune cells, to regulate tumor microenvironment and activate cellular immunity. The future prospects may involve in the rational combination of a few immunotherapies for more efficient cancer inhibition and elimination.

Feasible and pure P2O5-CaO nanoglasses: An in-depth NMR study of synthesis for the modulation of the bioactive ion release

The use of bioactive glasses (e.g. silicates, phosphates, borates) has demonstrated to be an effective therapy for the restoration of bone fractures, wound healing and vascularization. Their partial dissolution towards the surrounding tissue has shown to trigger positive bioactive responses, without the necessity of using growth factors or cell therapy, which reduces money-costs, side effects and increases their translation to the clinics. However, bioactive glasses often need from stabilizers (e.g. SiO₄^4-, Ti⁴⁺, Co²⁺, etc.) that are not highly abundant in the body and which metabolization is not fully understood. In this study, we were focused on synthesizing pure calcium phosphate glasses without the presence of such stabilizers. We combined a mixture of ethylphosphate and calcium 2-methoxyethoxide to synthesize nanoparticles with different compositions and degradability. Synthesis was followed by an in-depth nuclear magnetic resonance characterization, complemented with other techniques that helped us to correlate the chemical structure of the glasses with their physiochemical properties and reaction mechanism. After synthesis, the organically modified xerogel (i.e. calcium monoethylphosphate) was treated at 200 or 350 °C and its solubility was maintained and controlled due to the elimination of organics, increase of phosphate-calcium interactions and phosphate polycondensation. To the best of our knowledge, we are reporting the first sol-gel synthesis of binary (P₂O₅-CaO) calcium phosphate glass nanoparticles in terms of continuous polycondensated phosphate chains structure without the addition of extra ions. The main goal is to straightforward the synthesis, to get a safer metabolization and to modulate the bioactive ion release. Additionally, we shed light on the chemical structure, reaction mechanism and properties of calcium phosphate glasses with high calcium contents, which nowadays are poorly understood. STATEMENT OF SIGNIFICANCE: The use of bioactive inorganic materials (i.e. bioactive ceramics, glass-ceramics and glasses) for biomedical applications is attractive due to their good integration with the host tissue without the necessity of adding exogenous cells or growth factors. In particular, degradable calcium phosphate glasses are completely resorbable, avoiding the retention in the body of the highly stable silica network of silicate glasses, and inducing a more controllable degradability than bioactive ceramics. However, most calcium phosphate glasses include the presence of stabilizers (e.g. Ti⁴⁺, Na⁺, Co²⁺), which metabolization is not fully understood and complicates their synthesis. The development of binary calcium phosphate glasses with controlled degradability reduces these limitations, offering a simple and completely metabolizable material with higher transfer to the clinics.

Effects of Copper Chelation on BRAFV600E Positive Colon Carcinoma Cells

High affinity copper binding to mitogen-activated protein kinase kinase 1 (MAP2K1, also known as MEK1) allosterically promotes the kinase activity of MEK1/2 on extracellular signal regulated kinases 1 and 2 (ERK1/2). Consequently, copper-dependent activation of the mitogen-activated (MAP) kinase pathway has a role in promoting tumor growth. Conversely, copper chelation may represent a possible therapeutic approach for a specific subset of tumors characterized by activating mutations in the serine/threonine protein kinase V-Raf Murine Sarcoma Viral Oncogene Homolog B1 (BRAF), such as the V600E, occurring within the kinase domain (BRAF^V600E). Tetrathiomolybdate (TM) is a specific copper chelating agent currently used for the treatment of Wilson’s disease and in preclinical studies for the management of metastatic cancers owing to its anti-angiogenic and anti-inflammatory properties. We evaluated in vitro and in vivo the effects of copper depletion achieved by pharmacological treatment with TM in human colorectal cells bearing the BRAF^V600E mutation in comparison with BRAF wild type cells. We provide evidence that selective copper chelation differentially affects proliferation, survival and migration of colon cancer cells bearing the BRAF^V600E mutation compared to BRAF^wt acting via differential phosphorylation levels of ERK1/2. Moreover, tetrathiomolybdate treatment was also effective in reducing the clonogenic potential of colon cancer BRAF^V600E cells resistant to BRAF pharmacological inhibition. In conclusion, these results support further assessment of copper chelation therapy as an adjuvant therapy for inhibiting the progression of colon cancers containing the BRAF^V600E mutation.

Copper Chaperone for Superoxide Dismutase Promotes Breast Cancer Cell Proliferation and Migration via ROS-Mediated MAPK/ERK Signaling

Copper chaperone for superoxide dismutase (CCS) is a critical component of oxidation–reduction system and functions as a potential tumor promoter in several cancers. However, the function and clinical significance of CCS in breast cancer remain unclear. Here, we found CCS was highly expressed in breast cancer, where it promoted breast cancer cell proliferation and migration. Suppression of CCS expression was sufficient to attenuate the phosphorylation level of ERK1/2 and increase the accumulation of reactive oxygen species (ROS). Mechanistically, we found that knockdown of CCS decreases the activity of ERK1/2 mediated by the accumulation of ROS, which leads to the inhibition of cell proliferation and migration. In summary, these results indicated that CCS promotes the growth and migration of breast cancer cells via regulating the ERK1/2 activity mediated by ROS.

Copper(II) complexes as potential anticancer and Nonsteroidal anti-inflammatory agents: In vitro and in vivo studies

Copper-based compounds are promising entities for target-specific next-generation anticancer and NSAIDS therapeutics. In lieu of this, benzimidazole scaffold plays an important role, because of their wide variety of potential functionalizations and coordination modes. Herein, we report three copper complexes 1-3 with benzimidazole-derived scaffolds, a biocompatible molecule, and secondary ligands viz, 1-10-phenanthroline and 2,2'-bipyridyl. All the copper complexes have been designed, synthesized and adequately characterized using various spectroscopic techniques. In-vitro, human serum albumin (HSA) binding was also carried out using fluorescence technique and in-silico molecular modeling studies, which exhibited significant binding affinities of the complexes with HSA. Furthermore, copper complexes 1-3 were tested for biological studies, i.e., anticancer as well as NSAIDS. In vitro cytotoxicity results were carried out on cultured MCF-7 cell lines. To get the insight over the mechanism of action, GSH depletion and change in lipid peroxidation were tested and thus confirmed the role of ROS generation, responsible for the cytotoxicity of the complexes 1-3. Moreover, the copper complexes 1-3 were tested for potential to act as NSAIDS on albino rats and mice in animal studies in-vivo. Additionally, we also predicted the mechanism of action of the copper complexes 1-3 using molecular modeling studies with COX-2 inhibitor.