Antitumor Activity of Pt(II), Ru(III) and Cu(II) Complexes

RuIII-Morpholine-Derived Thiosemicarbazone-Based Metallodrugs: Lysosome-Targeted Anticancer Agents

The idea of coordinating biologically active ligand systems to metal centers to exploit their synergistic effects has gained momentum. Therefore, in this report, three RuIII complexes 1-3 of morpholine-derived thiosemicarbazone ligands have been prepared and characterized by spectroscopy and HRMS along with the structure of 2 through a single-crystal X-ray diffraction study. The solution stability of 1-3 was tested using conventional techniques such as UV-vis and HRMS. Further, the anticancer activity of 1-3 was tested in HT-29 and HeLa cancer cell lines. To gain insight into their mechanism of action, the cytotoxicity, hydrophobicity, and the interaction of 1-3 with DNA and HSA were evaluated by different conventional methods such as absorption, fluorescence, and circular dichroism studies. Along with favorable biomolecule interaction, 1-3 revealed potent selectivity toward cancer cells, which is a prerequisite for the generation of an anticancer drug. According to cell viability results, 1 has the highest cytotoxicity among all in the group, against both cells, respectively. Additionally, the fluorescence-active ruthenium complexes selectively target lysosomes, which is evaluated by live-cell imaging. 1-3 disrupt the lysosome membrane potential by generating an excessive amount of reactive oxygen species, which results in an apoptotic mode of cell death.

Recent Development of Fluoroquinolone Derivatives as Anticancer Agents

Cancer is the second leading cause of death in the world following cardiovascular disease. Its treatment, including radiation therapy and surgical removal of the tumour, is based on pharmacotherapy, which prompts a constant search for new and more effective drugs. There are high costs associated with designing, synthesising, and marketing new substances. Drug repositioning is an attractive solution. Fluoroquinolones make up a group of synthetic antibiotics with a broad spectrum of activity in bacterial diseases. Moreover, those compounds are of particular interest to researchers as a result of reports of their antiproliferative effects on the cells of the most lethal cancers. This article presents the current progress in the development of new fluoroquinolone derivatives with potential anticancer and cytotoxic activity, as well as structure-activity relationships, along with possible directions for further development.

Metal-(Acyclic Diaminocarbene) Complexes Demonstrate Nanomolar Antiproliferative Activity against Triple-Negative Breast Cancer

Hydrolytically stable PdII and PtII complexes supported by acyclic diaminocarbene ligands represent a novel class of structural organometallic anticancer agents exhibiting nanomolar antiproliferative activity in a panel of cancer cell lines (IC50 0.07-0.81 μM) and up to 300-fold selectivity for cancer cells over normal primary fibroblasts. The lead drug candidate was 300 times more potent than cisplatin in vitro and showed higher efficacy in reducing the growth of aggressive MDA-MB-231 xenograft tumors in mice.

Construction of a Cuproptosis-Related Gene Signature for Predicting Prognosis in Gastric Cancer

This study aimed to develop and validate a cuproptosis-related gene signature for the prognosis of gastric cancer. The data in TCGA GC TPM format from UCSC were extracted for analysis, and GC samples were randomly divided into training and validation groups. Pearson correlation analysis was used to obtain cuproptosis-related genes co-expressed with 19 Cuproptosis genes. Univariate Cox and Lasso regression analyses were used to obtain cuproptosis-related prognostic genes. Multivariate Cox regression analysis was used to construct the final prognostic risk model. The risk score curve, Kaplan-Meier survival curves, and ROC curve were used to evaluate the predictive ability of Cox risk model. Finally, the functional annotation of the risk model was obtained through enrichment analysis. Then, a six-gene signature was identified in the training cohort and verified among all cohorts using Cox regression analyses and Kaplan-Meier plots, demonstrating its independent prognostic significance for gastric cancer. In addition, ROC analysis confirmed the significant predictive potential of this signature for the prognosis of gastric cancer. Functional enrichment analysis was mainly related to cell-matrix function. Therefore, a new cuproptosis-related six-gene signature (ACLY, FGD6, SERPINE1, SPATA13, RANGAP1, and ADGRE5) was constructed for the prognosis of gastric cancer, allowing for tailored prediction of outcome and the formulation of novel therapeutics for gastric cancer patients.

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

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

A novel chiral oxazoline copper(II)-based complex inhibits ovarian cancer growth in vitro and in vivo by regulating VEGF/VEGFR2 downstream signaling pathways and apoptosis factors

A novel chiral oxazoline copper(II)-based complex {[Cu(C13H14NO3S)2]}2 (Cu-A) was synthesized by an in situ reaction using L-methioninol, 4-hydroxyisophthalaldehyde, sodium hydroxide and copper(II) nitrate trihydrate as reactants. Its crystal structure was characterized. In vitro, Cu-A was superior to cis-dichlorodiammineplatinum (DDP) in cytotoxicity and angiogenesis inhibition. Cu-A significantly induced apoptosis of ovarian cancer cells (SKOV3) and human umbilical vein endothelial cells (HUVECs), showing significant anti-ovarian cancer and anti-angiogenesis effects. Notably, Cu-A significantly inhibits the growth of ovarian cancer in nude mice xenografted with SKOV3 cells, and it is less renal toxic than DDP. The molecular mechanism of anti-ovarian cancer and anti-angiogenesis is possibly that it down-regulates the expression of the proteins ERK1/2, AKT, FAK, and VEGFR2 and their phosphorylated proteins p-ERK1/2, p-AKT, p-FAK, and p-VEGFR2 in the VEGF/VEGFR2 signal transduction pathway to inhibit SKOV3 cell and HUVEC proliferation, induce apoptosis, suppress migration and metastasis, and inhibit angiogenesis. What's more, Cu-A significantly inhibits ovarian tumor growth in vivo by inhibiting tumor cells from inducing vascular endothelial cells to form their own vasculature and by inhibiting the expression of the anti-apoptotic protein Bcl-2 and up-regulating the expression of the pro-apoptotic proteins Caspase-9 and Bax to induce apoptosis of tumor cells.

Plight of CORMs: The unreliability of four commercially available CO-releasing molecules, CORM-2, CORM-3, CORM-A1, and CORM-401, in studying CO biology

Carbon monoxide (CO) is an endogenously produced gaseous signaling molecule with demonstrated pharmacological effects. In studying CO biology, three delivery forms have been used: CO gas, CO in solution, and CO donors of various types. Among the CO donors, four carbonyl complexes with either a transition metal ion or borane (BH3) (termed CO-releasing molecules or CORMs) have played the most prominent roles appearing in over 650 publications. These are CORM-2, CORM-3, CORM-A1, and CORM-401. Intriguingly, there have been unique biology findings that were only observed with these CORMs, but not CO gas; yet these properties were often attributed to CO, raising puzzling questions as to why CO source would make such a fundamental difference in terms of CO biology. Recent years have seen a large number of reports of chemical reactivity (e.g., catalase-like activity, reaction with thiol, and reduction of NAD(P)+) and demonstrated CO-independent biological activity for these four CORMs. Further, CORM-A1 releases CO in an idiosyncratic fashion; CO release from CORM-401 is strongly influenced or even dependent on reaction with an oxidant and/or a nucleophile; CORM-2 mostly releases CO2, not CO, after a water-gas shift reaction except in the presence of a strong nucleophile; and CORM-3 does not release CO except in the presence of a strong nucleophile. All these beg the question as to what constitutes an appropriate CO donor for studying CO biology. This review critically summarizes literature findings related to these aspects, with the aim of helping result interpretation when using these CORMs and development of essential criteria for an appropriate donor for studying CO biology.

Copper metabolism and hepatocellular carcinoma: current insights

Copper is an essential trace element that acts as a cofactor in various enzyme active sites in the human body. It participates in numerous life activities, including lipid metabolism, energy metabolism, and neurotransmitter synthesis. The proposal of "Cuproptosis" has made copper metabolism-related pathways a research hotspot in the field of tumor therapy, which has attracted great attention. This review discusses the biological processes of copper uptake, transport, and storage in human cells. It highlights the mechanisms by which copper metabolism affects hepatocellular carcinogenesis and metastasis, including autophagy, apoptosis, vascular invasion, cuproptosis, and ferroptosis. Additionally, it summarizes the current clinical applications of copper metabolism-related drugs in antitumor therapy.

Anticancer Activity and Mode of Action of Cu(II), Zn(II), and Mn(II) Complexes with 5-Chloro-2-N-(2-quinolylmethylene)aminophenol

Developing a new generation of anticancer metal-based drugs that can both kill tumor cells and inhibit cell migration is a promising strategy. Herein, we synthesized three Cu(II), Zn(II), and Mn(II) complexes derived from 5-chloro-2-N-(2-quinolylmethylene)aminophenol (C1-C3). Among these complexes, the Cu(II) complex (C1) showed significantly greater cytotoxicity toward lung cancer cell lines than cisplatin. C1 inhibited A549 cell metastasis and suppressed the growth of the A549 tumor in vivo. In addition, we confirmed the anticancer mechanism of C1 by triggering multiple mechanisms, including inducing mitochondrial apoptosis, acting on DNA, blocking cell cycle arrest, inducing cell senescence, and inducing DNA damage.

Copper homeostasis dysregulation promoting cell damage and the association with liver diseases

ABSTRACT

Copper plays an important role in many metabolic activities in the human body. Copper level in the human body is in a state of dynamic equilibrium. Recent research on copper metabolism has revealed that copper dyshomeostasis can cause cell damage and induce or aggravate some diseases by affecting oxidative stress, proteasome, cuprotosis, and angiogenesis. The liver plays a central role in copper metabolism in the human body. Research conducted in recent years has unraveled the relationship between copper homeostasis and liver diseases. In this paper, we review the available evidence of the mechanism by which copper dyshomeostasis promotes cell damage and the development of liver diseases, and identify the future research priorities.

Copper (II) Species with Improved Anti-Melanoma and Antibacterial Activity by Inclusion in β-Cyclodextrin

To improve their biological activity, complexes [Cu(bipy)(dmtp)₂(OH₂)](ClO₄)₂·dmtp (1) and [Cu(phen)(dmtp)₂(OH₂)](ClO₄)₂·dmtp (2) (bipy 2,2'-bipyridine, phen: 1,10-phenantroline, and dmtp: 5,7-dimethyl-1,2,4-triazolo [1,5-a]pyrimidine) were included in β-cyclodextrins (β-CD). During the inclusion, the co-crystalized dmtp molecule was lost, and UV-Vis spectra together with the docking studies indicated the synthesis of new materials with 1:1 and 1:2 molar ratios between complexes and β-CD. The association between Cu(II) compounds and β-CD has been proven by the identification of the components' patterns in the IR spectra and powder XRD diffractograms, while solid-state UV-Vis and EPR spectra analysis highlighted a slight modification of the square-pyramidal stereochemistry around Cu(II) in comparison with precursors. The inclusion species are stable in solution and exhibit the ability to scavenge or trap ROS species (O₂·^- and HO·) as indicated by the EPR experiments. Moreover, the two inclusion species exhibit anti-proliferative activity against murine melanoma B16 cells, which has been more significant for (2)@β-CD in comparison with (2). This behavior is associated with a cell cycle arrest in the G0/G1 phase. Compared with precursors, (1a)@β-CD and (2a)@β-CD exhibit 17 and 26 times more intense activity against planktonic Escherichia coli, respectively, while (2a)@β-CD is 3 times more active against the Staphylococcus aureus strain.

Synthesis of Gingerol-Metals Complex and in-vitro Cytotoxic Activity on Human Colon Cancer Cell Line

Introduction

Herbs are excellent sources of medicinal substances, and their curative abilities have been recognized to treat many ailments and are used for example as antioxidants, analgesics, anti-inflammatories, antipyretics, and many other medicinal uses. The properties of natural compounds and their health effects have been studied extensively, especially those that originate from plant sources such as ginger. The ginger plant contains many chemical compounds, such as 6-gingerol, which is characterized by containing active groups such as carbonyl and hydroxide, which can be attached to metal molecules. This is what was done in this study, where the formation of complexes with a group of metals was studied and their effect on cancer cells was investigated. These complexes will open new horizons for further study of medicinal uses.

Methods

The synthesis of gingerol-metal complexes was carried out by conjugating gingerol molecules with Ag, Au, Cd, Co, Cu, Ni, and Zn metal ions. The extracted gingerol was transferred to culture tubes and deionized water-DMSO were added followed by sonication. The tubes were incubated at 90°C for two days as well as the control sample. The samples were then filtered and the complex solutions were transferred into new tubes for further studies. Different characterization techniques such as FT-IR, UV-vis spectroscopy, FESEM, and EDX are used to confirm the formation of the complexes. The in vitro of the complexes was tested by the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay against the human colorectal cancer cell lines HCT116 and HT29 which exhibited strong cytotoxicity.

Results

The gingerol-metal complexes showed an enhancement as an anticancer agent compared to the control. The in vitro anticancer activity showed that the Ag-gingerol complex showed the most activity among the other complexes.

Discussion

Gingerol-metal complexes can inhibit cancer cells, noting that the potency of the complex depends on the type of metal used.

Anticancer effect evaluation of iridium(III) complexes targeting mitochondria and endoplasmic reticulum

Ligand HMSPIP (2-(4-(methylsulfonyl)phenyl)-1H-imidazo[4,5-f][1,10]phenanthroline) and its iridium(III) complexes [Ir(ppy)₂(HMSPIP)]PF₆ (ppy = 2-phenylpyridine, Ir1) and [Ir(bzq)₂(HMSPIP)]PF₆ (bzq = benzo[h]quinoline, Ir2) were synthesized. The complexes were characterized by ¹H NMR, ¹³C NMR, and UV/Vis spectra. The cytotoxicity of the complexes toward cancer cells were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method, the scratch wound healing and colony-forming were also investigated. MTT assay certificated that the complexes show high toxic effect on the HeLa cells. The cell cycle assay illustrated that the complexes blocked cell growth at G₀/G₁ phase in HeLa cells. A series of subsequent experiments showed that the complexes first enter the endoplasmic reticulum (ER) and then enter the mitochondria, leading to an increase in intracellular Ca²⁺ and reactive oxygen species (ROS) content, depolarizing mitochondrial membrane potential (MMP), and ultimately resulting in apoptosis. In addition, the experimental results revealed that the complexes not only increase the level of ROS but also inhibit the production of GSH and eventually produce large amounts of MDA and further leading to cell death. Taken together, we consider that the complexes can be used as potential candidate drugs for HeLa cancer treatment.

RUNAT-BI: A Ruthenium(III) Complex as a Selective Anti-Tumor Drug Candidate against Highly Aggressive Cancer Cell Lines

Ruthenium compounds have demonstrated promising activity in different cancer types, overcoming several limitations of platinum-based drugs, yet their global structure-activity is still under debate. We analyzed the activity of Runat-BI, a racemic Ru(III) compound, and of one of its isomers in eight tumor cell lines of breast, colon and gastric cancer as well as in a non-tumoral control. Runat-BI was prepared with 2,2'-biimidazole and dissolved in polyethylene glycol. We performed assays of time- and dose-dependent viability, migration, proliferation, and expression of pro- and antiapoptotic genes. Moreover, we studied the growth rate and cell doubling time to correlate it with the apoptotic effect of Runat-BI. As a racemic mixture, Runat-BI caused a significant reduction in the viability and migration of three cancer cell lines from colon, gastric and breast cancer, all of which displayed fast proliferation rates. This compound also demonstrated selectivity between tumor and non-tumor lines and increased proapoptotic gene expression. However, the isolated isomer did not show any effect. Racemic Runat-BI is a potential drug candidate for treatment of highly aggressive tumors. Further studies should be addressed at evaluating the role of the other isomer, for a more precise understanding of its antitumoral potential and mechanism of action.

New anti-cancer explorations based on metal ions

Due to the urgent demand for more anti-cancer methods, the new applications of metal ions in cancer have attracted increasing attention. Especially the three kinds of the new mode of cell death, including ferroptosis, calcicoptosis, and cuproptosis, are of great concern. Meanwhile, many metal ions have been found to induce cell death through different approaches, such as interfering with osmotic pressure, triggering biocatalysis, activating immune pathways, and generating the prooxidant effect. Therefore, varieties of new strategies based on the above approaches have been studied and applied for anti-cancer applications. Moreover, many contrast agents based on metal ions have gradually become the core components of the bioimaging technologies, such as MRI, CT, and fluorescence imaging, which exhibit guiding significance for cancer diagnosis. Besides, the new nano-theranostic platforms based on metal ions have experimentally shown efficient response to endogenous and exogenous stimuli, which realizes simultaneous cancer therapy and diagnosis through a more controlled nano-system. However, most metal-based agents have still been in the early stages, and controlled clinical trials are necessary to confirm or not the current expectations. This article will focus on these new explorations based on metal ions, hoping to provide some theoretical support for more anti-cancer ideas.

Coinage Metal Compounds With 4-Methoxy-Diphenylphosphane Benzoate Ligand Inhibit Female Cancer Cell Growth

In the continuous effort to find new metal-based compounds as alternatives to platinum-related anticancer drugs, 11th group metal phosphane compounds have been thoroughly taken into consideration. Tris-arylphosphane metal derivatives have been extensively considered as heteroleptic metal compounds exhibiting remarkable cytotoxic activities. Functional groups in the aryl moieties modulate the activity reinforcing or eliminating it. Previous works have highlighted that the presence of hydrophilic groups in the phosphane ligands, such as COOH or OH, hampers the anticancer activity of gold azolate/PPh3 compounds. To increase the polarity of the triarylphosphane ligand without affecting the activity, we considered the preparation of esters starting from the 4-diphenylphosphane-benzoic acid. The resulting phosphanes are poorer donators than the PPh3, leading to poly-phosphane M(I) compounds, and they exhibit intense emissive properties. A homologous series of L3MX-type compounds (where M = Au and X = Cl, M = Cu and X = BF4, and M = Ag and X = PF6) were obtained with the 4-methoxy-diphenylphosphane benzoate. The homologous metal compounds have been characterized by analytical and spectroscopic methods and, remarkably, their formation was associated with high frequencies of 31P NMR chemical shift variations (5–35 ppm in CDCl3). The new complexes and the ligand were evaluated on sensitive and cisplatin-resistant human tumor cell lines. The ligand is ineffective on cells while the complexes exert a notable antiproliferative effect. The homologous series of the L3MX complexes were able to significantly reduce the cell viability of human triple-negative breast cancer cells (MDA-MB-231), representing the most aggressive subtype of breast cancer, and of ovarian carcinoma (A2780). Among these coinage metal compounds, L3AgPF6 results the most interesting, showing the lowest GI50 values in all cell lines. Interestingly, this silver complex is more cytotoxic than cisplatin, taken as reference drug. The investigation of the mechanism of action of L3AgPF6 in A2780 cells highlighted the induction of the apoptotic pathway, the depolarization of the mitochondrial inner membrane, and a significant accumulation in cells.

Synthesis, Characterization and Antitumor Mechanism Investigation of Heterometallic Ru(Ⅱ)-Re(Ⅰ) Complexes

The development of heteronuclear metal complexes as potent anticancer agents has received increasing attention in recent years. In this study, two new heteronuclear Ru(Ⅱ)-Re(Ⅰ) metal complexes, [Ru(bpy)₂LRe(CO)₃(DIP)](PF₆)₃ and [Ru(phen)₂LRe(CO)₃(DIP)](PF₆)₃ [RuRe-1 and RuRe-2, L = 2-(4-pyridinyl)imidazolio[4,5-f][1,10]phenanthroline, bpy = 2,2′-bipyridine, DIP = 4,7-diphenyl-1,10-phenanthroline, phen = 1,10-phenanthroline], were synthesized and characterized. Cytotoxicity assay shows that RuRe-1 and RuRe-2 exhibit higher anticancer activity than cisplatin, and exist certain selectivity toward human cancer cells over normal cells. The anticancer mechanistic studies reveal that RuRe-1 and RuRe-2 can induce apoptosis through the regulation of cell cycle, depolarization of mitochondrial membrane potential (MMP), elevation of intracellular reactive oxygen species (ROS), and caspase cascade. Moreover, RuRe-1 and RuRe-2 can effectively inhibit cell migration and colony formation. Taken together, heteronuclear Ru(Ⅱ)-Re(Ⅰ) metal complexes possess the prospect of developing new anticancer agents with high efficacy.

N6-methyladenosine(m6A) demethylase FTO regulates cellular apoptosis following cobalt-induced oxidative stress

Cobalt is an environmental toxicant that is known to damage human health. However, the molecular mechanisms underlying cobalt-induced neurotoxicity have not been elucidated in detail. In the present research, we used human neuroglioma H4 cells as an in vitro model. Cells were exposed to CoCl₂ (0, 100, 200, 400 μM) for 24 h. We performed m⁶A sequencing techniques and constructed FTO-knockdown/FTO-overexpressing cells to investigate the role of FTO-mediated m⁶A modification in regulating apoptosis following CoCl₂ induced oxidative stress. Our study has shown CoCl₂ exposure led to the decrease of demethylase FTO as well as elevated oxidative stress. However, NAC treatment could partly reverse the reduction of FTO expression as well as the degree of ROS via eliminating oxidative stress. Meanwhile, MeRIP-seq and RNA-seq further revealed the potential function m⁶A modification in regulating apoptosis. More importantly, KEGG pathway and Gene ontology (GO) analyses further elucidated that the differentially m⁶A-modified genes were aggregated in apoptosis-related pathways. Mechanistic analysis indicated that knockdown of FTO facilitated CoCl₂-induced apoptosis via caspase activation and G1/S cell cycle arrest. Nevertheless, overexpression of FTO partly attenuated the increased apoptosis following CoCl₂ exposure. More notably, we observed that FTO regulated apoptosis in an m⁶A-dependent manner. Therefore, our findings reveal that CoCl₂ induced ROS affected the m⁶A modification of apoptosis-related genes by decreasing the expression of FTO, thereby resulting in the activation of apoptosis. These findings provide important insights into CoCl₂-induced apoptosis and m⁶A modification and propose a novel strategy for studying environmental toxicant-related neurodegeneration.

Insights into Structure and Biological Activity of Copper(II) and Zinc(II) Complexes with Triazolopyrimidine Ligands

In an attempt to increase the biological activity of the 1,2,4-triazolo[1,5-a]pyrimidine scaffold through complexation with essential metal ions, the complexes trans-[Cu(mptp)₂Cl₂] (1), [Zn(mptp)Cl₂(DMSO)] (2) (mptp: 5-methyl-7-phenyl-1,2,4-triazolo[1,5-a]pyrimidine), [Cu₂(dmtp)₄Cl₄]·2H₂O (3) and [Zn(dmtp)₂Cl₂] (4) (dmtp: 5,7-dimethyl-1,2,4-triazolo[1,5-a]pyrimidine), were synthesized and characterized as new antiproliferative and antimicrobial species. Both complexes (1) and (2) crystallize in the P2₁/n monoclinic space group, with the tetrahedral surroundings generating a square-planar stereochemistry in the Cu(II) complex and a tetrahedral stereochemistry in the Zn(II) species. The mononuclear units are interconnected in a supramolecular network through π–π interactions between the pyrimidine moiety and the phenyl ring in (1) while supramolecular chains resulting from C-H∙∙∙π interactions were observed in (2). All complexes exhibit an antiproliferative effect against B16 tumor cells and improved antibacterial and antifungal activities compared to the free ligands. Complex (3) displays the best antimicrobial activity against all four tested strains, both in the planktonic and biofilm-embedded states, which can be correlated to its stronger DNA-binding and nuclease-activity traits.

Copper-induced tumor cell death mechanisms and antitumor theragnostic applications of copper complexes

Recent studies found that unbalanced copper homeostasis affect tumor growth, causing irreversible damage. Copper can induce multiple forms of cell death, including apoptosis and autophagy, through various mechanisms, including reactive oxygen species accumulation, proteasome inhibition, and antiangiogenesis. Hence, copper in vivo has attracted tremendous attention and is in the research spotlight in the field of tumor treatment. This review first highlights three typical forms of copper's antitumor mechanisms. Then, the development of diverse biomaterials and nanotechnology allowing copper to be fabricated into diverse structures to realize its theragnostic action is discussed. Novel copper complexes and their clinical applications are subsequently described.

Unravelling the anticancer potential of a square planar copper complex: toward non-platinum chemotherapy

Coordination compounds from simple transition metals are robust substitutes for platinum-based complexes due to their remarkable anticancer properties. In a quest to find new metal complexes that could substitute or augment the platinum based chemotherapy we synthesized three transition metal complexes C1-C3 with Cu(ii), Ni(ii), and Co(ii) as the central metal ions, respectively, and evaluated them for their anticancer activity against the human keratinocyte (HaCaT) cell line and human cervical cancer (HeLa) cell lines. These complexes showed different activity profiles with the square planar copper complex C1 being the most active with IC50 values lower than those of the widely used anticancer drug cisplatin. Assessment of the morphological changes by DAPI staining and ROS generation by DCFH-DA assay exposed that the cell death occurred by caspase-3 mediated apoptosis. C1 displayed interesting interactions with Ct-DNA, evidenced by absorption spectroscopy and validated by docking studies. Together, our results suggest that binding of the ligand to the DNA-binding domain of the p53 tumor suppressor (p53DBD) protein and the induction of the apoptotic hallmark protein, caspase-3, upon treatment with the metal complex could be positively attributed to a higher level of ROS and the subsequent DNA damage (oxidation), generated by the complex C1, that could well explain the interesting anticancer activity observed for this complex.

Biological properties and conformational studies of amphiphilic Pd(II) and Ni(II) complexes bearing functionalized aroylaminocarbo-N-thioylpyrrolinate units

A series of novel palladium(II) and nickel(II) complexes of multifunctionalized aroylaminocarbo-N-thioylpyrrolinates were synthesized and characterized by analytical and spectroscopic techniques. The biological properties of the freshly prepared compounds were screened against S. aureus, B. subtilis, A. hydrophila, E. coli, and A. baumannii bacteria and antituberculosis activity against M. tuberculosis H37Rv strains. Also, the antifungal activity was studied against C. albicans, C. tropicalis, and C. glabrata standard strains. A deep conformational survey was monitored using DFT calculations with the aim to explain the importance of the final conformation in the biological experimental results.

Discovery of metal-based complexes as promising antimicrobial agents

The antimicrobial resistance (AMR) is an intractable problem for the world. Metal ions are essential for the cell process and biological function in microorganisms. Many metal-based complexes with the potential for releasing ions are more likely to be absorbed for their higher lipid solubility. Hence, this review highlights the clinical potential of organometallic compounds for the treatment of infections caused by bacteria or fungi in recent five years. The common scaffolds, including antimicrobial peptides, N-heterocyclic carbenes, Schiff bases, photosensitive-grand-cycle skeleton structures, aliphatic amines-based ligands, and special metal-based complexes are summarized here. We also discuss their therapeutic targets and the risks that should be paid attention to in the future studies, aiming to provide information for researchers on metal-based complexes as antimicrobial agents and inspire the design and synthesis of new antimicrobial drugs.

Elaborated study of Cu(II) carbosilane metallodendrimers bearing substituted iminopyridine moieties as antitumor agents

Iminopyridine-decorated carbosilane metallodendrimers have recently emerged as a promising strategy in the treatment of cancer diseases. Their unique features such as the nanometric size, the multivalent nature and the structural perfection offer an extraordinary platform to explore structure-to-property relationships. Herein, we showcase the outstanding impact on the antitumor activity of a parameter not explored before: the iminopyridine substituents in meta position. New Cu(II) carbosilane metallodendrimers, bearing methyl or methoxy substituents in the pyridine ring, were synthesized and thoroughly characterized. Electron Paramagnetic Resonance (EPR) was exploited to unveil the properties of the metallodendrimers. This study confirmed the presence of different coordination modes of the Cu(II) ion (Cu-N₂O₂, Cu-N₄ and Cu-O₄), whose ratios were determined by the structural features of the dendritic molecules. These metallodendrimers exhibited IC₅₀ values in the low micromolar range (<6 μM) in tumor cell lines such as HeLa and MCF-7. The subsequent in vitro assays on both healthy (PBMC) and tumor (U937) myeloid cells revealed two key facts which improved the cytotoxicity and selectivity of the metallodrug: First, maximizing the Cu-N₂O₂ coordination mode; second, adequately selecting the pair ring-substituent/metal-counterion. The most promising candidates, G₁(-CH₃)Cl (8) and G₁(-OCH₃)NO₃(17), exhibited a substantial increase in the antitumor activity in U937 tumor cells, compared to the non-substituted counterparts, probably through two different ROS-production pathways.

Synthesis of Platinum(II) Complexes with Some 1-Methylnitropyrazoles and In Vitro Research on Their Cytotoxic Activity

A series of eight novel platinum(II) complexes were synthesized by the reaction of the appropriate 1-methylnitropyrazole derivatives with K₂PtCl₄ and characterized by elemental analysis, ESI MS spectrometry, ¹H NMR, ¹⁹⁵Pt NMR, IR and far IR spectroscopy. Thermal isomerization of cis-dichloridobis(1-methyl-4-nitropyrazole)platinum(II) 1 to trans-dichloridobis(1-methyl-4-nitropyrazole)platinum(II) 2 has been presented, and the structure of the compound 2 has been confirmed by X-ray diffraction method. Cytotoxicity of the investigated compounds was examined in vitro on three human cancer cell lines (MCF-7 breast, ES-2 ovarian and A-549 lung adenocarcinomas) and their logP was measured using a shake-flask method. The trans complex 2 showed better antiproliferative activity than cisplatin for all the tested cancer cell lines. Additionally, trans-dichloridobis(1-methyl-5-nitropyrazole)platinum(II) 4 has featured a lower IC₅₀ value than reference cisplatin against MCF-7 cell line. To gain additional information that may facilitate the explanation of the mode of action of tested compounds cellular platinum uptake, stability in L-glutathione solution, influence on cell cycle progression of HL-60 cells and ability to apoptosis induction were determined for compounds 1 and 2.