Novel mono-, bi-, tri- and tetra-nuclear copper complexes that inhibit tumor growth through apoptosis and anti-angiogenesis

Albumin-based nanocarriers loaded with novel Zn(II)-thiosemicarbazone compounds chart a new path for precision breast cancer therapy

This study explores the therapeutic potential of albumin-bound Zn(II)-thiosemicarbazone compounds (Alb-ZnTcA, Alb-ZnTcB) against breast cancer cells. Previous research indicates that these compounds hinder cancer cell proliferation by blocking DNA synthesis, promoting oxidative stress to induce apoptosis, and disrupting the cell cycle to inhibit cellular division. This study focuses on the loading and characterization of these potentially chemically unstable compounds on bovine serum albumin-based nanocarriers. Accordingly, unlike previous studies using albumin nanoparticles, in this study, ultraviolet light was used to precisely bind the therapeutic agent to albumin during the integration of thiosemicarbazones, achieving controlled nanoparticle size to control nanoparticle size. The mean diameter of Alb-ZnTcA nanoparticles was 32 nm, while Alb-ZnTcB exhibited an average diameter of 43 nm. Notably, Alb-ZnTcA displayed the highest cytotoxicity toward breast cancer cells, suggesting an optimal size for cellular uptake. Additionally, albumin-bound compounds showed enhanced cytotoxicity at lower concentrations, potentially minimizing adverse side effects. Apoptosis analysis indicated that both Alb-ZnTcA and Alb-ZnTcB induce cell death predominantly through apoptosis, effectively preventing the uncontrolled proliferation of cancer cells. These findings demonstrate the potential of Zn(II)-thiosemicarbazone compounds loaded on albumin-based nanocarriers for breast cancer treatment. The increased potency of Alb-ZnTcA and Alb-ZnTcB compared to free compounds, along with their ability to activate apoptotic signaling pathways in MCF-7 breast cancer cells, highlights a promising approach for future cancer therapies. This study suggests that albumin-bound Zn(II)-thiosemicarbazone compounds could offer a targeted and effective strategy in breast cancer treatment, leveraging the advantages of nanocarrier-based delivery systems.

Mechanisms of Copper-Induced Autophagy and Links with Human Diseases

As a structural and catalytic cofactor, copper is involved in many biological pathways and is required for the biochemistry of all living organisms. However, excess intracellular copper can induce cell death due to its potential to catalyze the generation of reactive oxygen species, thus copper homeostasis is strictly regulated. And the deficiency or accumulation of intracellular copper is connected with various pathological conditions. Since the success of platinum-based compounds in the clinical treatment of various types of neoplasias, metal-based drugs have shown encouraging perspectives for drug development. Compared to platinum, copper is an essential intracellular trace element that may have better prospects for drug development than platinum. Recently, the potential therapeutic role of copper-induced autophagy in chronic diseases such as Parkinson's, Wilson's, and cardiovascular disease has already been demonstrated. In brief, copper ions, numerous copper complexes, and copper-based nano-preparations could induce autophagy, a lysosome-dependent process that plays an important role in various human diseases. In this review, we not only focus on the current advances in elucidating the mechanisms of copper or copper-based compounds/preparations on the regulation of autophagy but also outline the association between copper-induced autophagy and human diseases.

Selenium-Chondroitin Sulfate Nanoparticles Inhibit Angiogenesis by Regulating the VEGFR2-Mediated PI3K/Akt Pathway

Chondroitin sulfate (CS), a class of glycosaminoglycans covalently attached to proteins to form proteoglycans, is widely distributed in the extracellular matrix and cell surface of animal tissues. In our previous study, CS was used as a template for the synthesis of seleno-chondroitin sulfate (SeCS) through the redox reaction of ascorbic acid (Vc) and sodium selenite (Na2SeO3) and we found that SeCS could inhibit tumor cell proliferation and invasion. However, its effect on angiogenesis and its underlying mechanism are unknown. In this study, we analyzed the effect of SeCS on tube formation in vitro, based on the inhibition of tube formation and migration of human umbilical vein endothelial cells (HUVECs), and evaluated the in vivo angiogenic effect of SeCS using the chick embryo chorioallantoic membrane (CAM) assay. The results showed that SeCS significantly inhibited the angiogenesis of chicken embryo urothelium. Further mechanism analysis showed that SeCS had a strong inhibitory effect on VEGFR2 expression and its downstream PI3K/Akt signaling pathway, which contributed to its anti-angiogenic effects. In summary, SeCS showed good anti-angiogenic effects in an HUVEC cell model and a CAM model, suggesting that it may be a potential angiogenesis inhibitor.

Advancements in breast cancer therapy: The promise of copper nanoparticles

BACKGROUND

Breast cancer (BC) is the most prevalent cancer among women worldwide and poses significant treatment challenges. Traditional therapies often lead to adverse side effects and resistance, necessitating innovative approaches for effective management.

OBJECTIVE

This review aims to explore the potential of copper nanoparticles (CuNPs) in enhancing breast cancer therapy through targeted drug delivery, improved imaging, and their antiangiogenic properties.

METHODS

The review synthesizes existing literature on the efficacy of CuNPs in breast cancer treatment, addressing common challenges in nanotechnology, such as nanoparticle toxicity, scalability, and regulatory hurdles. It proposes a novel hybrid method that combines CuNPs with existing therapeutic modalities to optimize treatment outcomes.

RESULTS

CuNPs demonstrate the ability to selectively target cancer cells while sparing healthy tissues, leading to improved therapeutic efficacy. Their unique physicochemical properties facilitate efficient biodistribution and enhanced imaging capabilities. Additionally, CuNPs exhibit antiangiogenic activity, which can inhibit tumor growth by preventing the formation of new blood vessels.

CONCLUSION

The findings suggest that CuNPs represent a promising avenue for advancing breast cancer treatment. By addressing the limitations of current therapies and proposing innovative solutions, this review contributes valuable insights into the future of nanotechnology in oncology.

Anticancer activity of new water-soluble sulfonated thiosemicarbazone copper(II) complexes targeting disulfide isomerase

Copper complexes have shown promising anticancer properties, but they are often poorly soluble in aqueous solutions, thus limiting their possible medical developments and applications. We have recently isolated some copper(II) complexes with salicylaldehyde thiosemicarbazone ligands exhibiting remarkable nanomolar cytotoxic activity, but in vivo tests evidenced several difficulties related to their poor solubility. To overcome these limitations and increase solubility in aqueous solution, herein we report the synthetic strategy that led to the introduction of the sulfonic group on the ligands, then separated as salts (NaH2L1 - NaH2L5), as well as the synthesis and characterization of the related copper(II) complexes. The characterization of the complexes is completed by the analysis of the structures obtained by X-rays diffraction on single crystals on the species [Cu(HL5)(H2O)]2.2H2O, [Cu(HL2)(H2O)2].2H2O, and [Cu(HL1)(H2O]2.2H2O. While the uncoordinated ligands do not affect cancer cell viability, copper(II) complexes exhibit low to sub-micromolar cytotoxic activity, which is maintained in 3D (HCT-15 and 2008) spheroidal models of cancer cell. Notably, copper(II) complexes were selective towards cancer cells, showing high selectivity indexes. Investigations focused on elucidating the mechanism of action evidenced the protein disulfide-isomerase as an innovative molecular target for this class of water-soluble copper(II) complexes. Finally, preliminary in vivo experiments performed with the most representative derivative in the murine Lewis Lung Carcinoma, highlight its significant antitumor efficacy and better tolerability profile with respect to the reference metallodrug, suggesting for this sulfonated Cu(II) complex a potential clinical relevance.

Recent advances in copper homeostasis-involved tumor theranostics

As the third essential trace element in the human body, copper plays a crucial role in various physiological processes, which lays the foundation for its broad applications in cancer treatments. The overview of copper, including pharmacokinetics, signaling pathways, and homeostasis dysregulation, is hereby discussed. Additionally, cuproptosis, as a newly proposed cell death mechanism associated with copper accumulation, is analyzed and further developed for efficient cancer treatment. Different forms of Cu-based nanoparticles and their advantages, as well as limiting factors, are introduced. Moreover, the unique characteristics of Cu-based nanoparticles give rise to their applications in various imaging modalities. In addition, Cu-based nanomaterials are featured by their excellent photothermal property and ROS-associated tumor-killing potential, which are widely explored in diverse cancer therapies and combined therapies. Reducing the concentration of Cu2+/Cu+ is another cancer-killing method, and chelators can meet this need. More importantly, challenges and future prospects are identified for further research.

Synthesis, Structural Characterisation, and Electrochemical Properties of Copper(II) Complexes with Functionalized Thiosemicarbazones Derived from 5-Acetylbarbituric Acid

The reaction between 5-acetylbarbituric acid and 4-dimethylthiosemicarbazide or 4-hexamethyleneiminyl thiosemicarbazide produces 5-acetylbarbituric-4-dimethylthiosemicarbazone (H2AcbDM) and 5-acetylbarbituric-4N-hexamethyleneiminyl thiosemicarbazone (H2Acbhexim). Eight new complexes with different copper(II) salts have been prepared and characterized using elemental analysis, molar conductance, UV-Vis, ESI-HRMS, FT-IR, magnetic moment, EPR, and cyclic voltammetry. In addition, three-dimensional molecular structures of [Cu(HAcbDM)(H2O)2](NO3)·H2O (3a), [Cu(HAcbDM)(H2O)2]ClO4 (4), and [Cu(HAcbHexim)Cl] (6) were determined by single crystal X-ray crystallography, and an analysis of their supramolecular structure was carried out. The H-bonded assemblies were further studied energetically using DFT calculations and MEP surface and QTAIM analyses. In these complexes, the thiosemicarbazone coordinates to the metal ion in an ONS-tridentate manner, in the O-enolate/S-thione form. The electrochemical behavior of the thiosemicarbazones and their copper(II) complexes has been investigated at room temperature using the cyclic voltammetry technique in DMFA. The Cu(II)/Cu(I) redox system was found to be consistent with the quasi-reversible diffusion-controlled process.

Arene-Arene Coupled Disulfamethazines (or Sulfadiazine)-Phenanthroline-Metal(II) Complexes were Synthesized by In Situ Reactions and Inhibited the Growth and Development of Triple-Negative Breast Cancer through the Synergistic Effect of Antiangiogenesis, Anti-Inflammation, Pro-Apoptosis, and Cuproptosis

The novel metal(II)-based complexes HA-Cu, HA-Co, and HA-Ni with phenanthroline, sulfamethazine, and aromatic-aromatic coupled disulfamethazines as ligands were synthesized and characterized. HA-Cu, HA-Co, and HA-Ni all showed a broad spectrum of cytotoxicity and antiangiogenesis. HA-Cu was superior to HA-Co and HA-Ni, and even superior to DDP, showing significant inhibitory effect on the growth and development of tripe-negative breast cancer in vivo and in vitro. HA-Cu exhibited observable synergistic effects of antiproliferation, antiangiogenesis, anti-inflammatory, pro-apoptosis, and cuproptosis to effectively inhibited tumor survival and development. The molecular mechanism was confirmed that HA-Cu could downregulate the expression of key proteins in the VEGF/VEGFR2 signaling pathway and the expression of inflammatory cytokines, enhance the advantage of pro-apoptotic protein Bax, and enforce cuproptosis by weakening the expression of FDX1 and enhancing the expression of HSP70. Our research will provide a theoretical and practical reference for the development of metal-sulfamethazine and its derivatives as chemotherapy drugs for cancer treatment.

Unveiling the promising anticancer effect of copper-based compounds: a comprehensive review

Copper is a necessary micronutrient for maintaining the well-being of the human body. The biological activity of organic ligands, especially their anticancer activity, is often enhanced when they coordinate with copper(I) and (II) ions. Copper and its compounds are capable of inducing tumor cell death through various mechanisms of action, including activation of apoptosis signaling pathways by reactive oxygen species (ROS), inhibition of angiogenesis, induction of cuproptosis, and paraptosis. Some of the copper complexes are currently being evaluated in clinical trials for their ability to map tumor hypoxia in various cancers, including locally advanced rectal cancer and bulky tumors. Several studies have shown that copper nanoparticles can be used as effective agents in chemodynamic therapy, phototherapy, hyperthermia, and immunotherapy. Despite the promising anticancer activity of copper-based compounds, their use in clinical trials is subject to certain limitations. Elevated copper concentrations may promote tumor growth, angiogenesis, and metastasis by affecting cellular processes.

Human Serum Albumin-Platinum(II) Agent Nanoparticles Inhibit Tumor Growth Through Multimodal Action Against the Tumor Microenvironment

To overcome the limitations of traditional platinum (Pt)-based drugs and further improve the targeting ability and therapeutic efficacy in vivo, we proposed to design a human serum albumin (HSA)-Pt agent complex nanoparticle (NP) for cancer treatment by multimodal action against the tumor microenvironment. We not only synthesized a series of Pt(II) di-2-pyridone thiosemicarbazone compounds and obtained a Pt(II) agent [Pt(Dp44mT)Cl] with significant anticancer activity but also successfully constructed a novel HSA-Pt(Dp44mT) complex nanoparticle delivery system. The structure of the HSA-Pt(Dp44mT) complex revealed that Pt(Dp44mT)Cl binds to the IIA subdomain of HSA and coordinates with His-242. The HSA-His242-Pt-Dp44mT NPs had an obvious effect on the inhibition of tumor growth, which was superior to that of Dp44mT and Pt(Dp44mT)Cl, and they had almost no toxicity. In addition, the HSA-His242-Pt-Dp44mT NPs were found to kill cancer cells by inducing apoptosis, autophagy, and inhibiting angiogenesis.