Targeting TRIM26: Unveiling an Oncogene and Identification of Plant Metabolites as a Potential Therapeutics for Breast Cancer

Breast cancer is the major cause of cancer-related mortality and frequent malignancies among women worldwide. The TRIM (Tripartite Motif) protein family is a broad and diverse set of proteins that contain a conserved structural motif known as the tripartite motif, which comprises of three different domains, B-box domain, Coiled-coil domain and RBR (Ring-finger, B-box, and coiled-coil) domain. TRIM proteins are involved in regulating cancer growth and metastasis. However, TRIM proteins are still unexplored in cancer cell regulation. In this study, by using a cancer database expression of all TRIM proteins was determined in breast cancer. Out of 77 TRIM genes, 16 genes were upregulated in breast cancer. Here, the upregulated TRIM26 gene's role is not yet explored in breast cancer. Indeed, TRIM26 is upregulated in 21 cancer types out of 33 cancer types. To investigate the role of TRIM26 in breast cancer, siRNA-mediated gene silencing was carried out in MCF-7 and MDA-MB 231 breast cancer cells. Reduced expression of TRIM 26 decreased cancer cell proliferation, migration and invasion with simultaneous reduction of various proliferative, cell cycle and mesenchymal markers and upregulation of epithelial markers. Further, docking studies found potential novel plant metabolites. Thus, targeting TRIM26 may provide a novel therapeutic approach for breast cancer treatment.

The Therapeutic Potential in Cancer of Terpyridine-Based Metal Complexes Featuring Group 11 Elements

Terpyridine-based complexes with group 11 metals emerge as potent metallodrugs in cancer therapy. This comprehensive review focuses on the current landscape of anticancer examples, particularly highlighting the mechanisms of action. While Cu(II) complexes, featuring diverse ancillary ligands, dominate the field, exploration of silver and gold species remains limited. These complexes exhibit significant cytotoxicity against various cancer cell lines with a commendable selectivity for non-tumorigenic cells. DNA interactions, employing intercalation and groove binding, are pivotal and finely tuned through terpyridine ligand functionalization. In addition, copper complexes showcase nuclease activity, triggering apoptosis through ROS generation. Despite silver's high affinity for nitrogen donor atoms, its exploration is relatively sparse, with indications of acting as intercalating agents causing DNA hydrolytic cleavage. Gold(III) compounds, overshadowing gold(I) due to stability concerns, not only intercalate but also induce apoptosis and disrupt the mitochondrial membrane. Further investigations are needed to fully understand the mechanism of action of these compounds, highlighting the necessity of exploring additional biological targets for these promising metallodrugs.

Copper(II) Complexes with 2,2':6',2″-Terpyridine Derivatives Displaying Dimeric Dichloro-μ-Bridged Crystal Structure: Biological Activities from 2D and 3D Tumor Spheroids to In Vivo Models

Eight 2,2':6',2″-terpyridines, substituted at the 4'-position with aromatic groups featuring variations in π-conjugation, ring size, heteroatoms, and methoxy groups, were employed to enhance the antiproliferative potential of [Cu2Cl2(R-terpy)2](PF6)2. Assessing the cytotoxicity in A2780 (ovarian carcinoma), HCT116 (colorectal carcinoma), and HCT116DoxR (colorectal carcinoma resistant to doxorubicin) and normal primary fibroblasts revealed that Cu(II) complexes with 4-quinolinyl, 4-methoxy-1-naphthyl, 2-furanyl, and 2-pyridynyl substituents showed superior therapeutic potential in HCT116DoxR cells with significantly reduced cytotoxicity in normal fibroblasts (42-129× lower). Besides their cytotoxicity, the Cu(II) complexes are able to increase intracellular ROS and interfere with cell cycle progression, leading to cell death by apoptosis and autophagy. Importantly, they demonstrated antimetastatic and antiangiogenic properties without in vivo toxicity. In accordance with their nuclear accumulation, the Cu(II) complexes are able to cleave pDNA and interact with bovine serum albumin, which is a good indication of their ability for internalization and transport toward tumor cells.

Hydrazylpyridine salicylaldehyde-copper(II)-1,10-phenanthroline complexes as potential anticancer agents: synthesis, characterization and anticancer evaluation

We synthesized and analyzed nine unique copper(II) hydrazylpyridine salicylaldehyde and 1,10-phenanthroline complexes, [Cu(L1a)(phen)] (Cugdupt1), [Cu(L2a)(phen)]·(CH3CN) (Cugdupt2), [Cu(L3a)(phen)] (Cugdupt3), [Cu(L4a)(phen)]·(CH3CN) (Cugdupt4), [Cu(L5a)(phen)] (Cugdupt5), [Cu(L6a)(phen)] (Cugdupt6), [Cu(L7a)(phen)] (Cugdupt7) [Cu(L8a)(phen)] (Cugdupt8) and [Cu(L9a)(phen)]·0.5(H2O) (Cugdupt9). We were motivated by the intriguing properties of the coupled ligands of hydrazylpyridine, salicylaldehyde, and 1,10-phenanthroline. The MTT assay demonstrated that Cugdupt1-Cugdupt9 have higher anticancer activity than L1H2-L9H2, phen and cisplatin on A549/DDP cancer cells (A549cis). Cugdupt1-Cugdupt9 were superior to cisplatin with IC50 values of 1.6-100.0 fold on A549cis cells (IC50(Cugdupt1-Cugdupt9) = 0.5-30.5 μM, IC50(cisplatin) = 61.5 ± 1.0 μM). However, Cugdupt1-Cugdupt9 had lower cytotoxicity toward the HL-7702 normal cells. Cugdupt1 and Cugdupt8 can induce reduction of mitochondrial respiratory chain complexes I/IV (MRCC-I/IV), mitophagy pathways, and eventually protein regulation and adenosine triphosphate (ATP) depletion in A549cis cells. The findings indicated that Cugdupt1 and Cugdupt8 caused cell death via both ATP diminution and mitophagy pathways. Finally, Cugdupt8 demonstrated high efficacy and no obvious cytotoxicity in A549 tumor-bearing mice. This study thus helps evaluate the potential of the hydrazylpyridine salicylaldehyde-copper(II)-1,10-phenanthroline compounds for cisplatin-resistant tumor therapy.

In vitro and in vivo antitumor activities of Ru and Cu complexes with terpyridine derivatives as ligands

Six terpyridine ligands(L1-L6) with chlorophenol or bromophenol moiety were obtained to prepare metal terpyridine derivatives complexes: [Ru(L1)(DMSO)Cl2] (1), [Ru(L2)(DMSO)Cl2] (2), [Ru(L3)(DMSO)Cl2] (3), [Cu(L4)Br2]·DMSO (4), Cu(L5)Br2 (5), and [Cu(L6)Br2]⋅CH3OH (6). The complexes were fully characterized. Ru complexes 1-3 showed low cytotoxicity against the tested cell lines. Cu complexes 4-6 exhibited higher cytotoxicity against several tested cancer cell lines compared to their ligands and cisplatin, and lower toxicity towards normal human cells. Copper(II) complexes 4-6 arrested T-24 cell cycle in G1 phase. The mechanism studies indicated that complexes 4-6 accumulated in mitochondria of T-24 cells and caused significant reduction of the mitochondrial membrane potential, increase of the intracellular ROS levels and the release of Ca2+, and the activation of the Caspase cascade, finally inducing apoptosis. Animal studies showed that complex 6 obviously inhibited the tumor growth in a mouse xenograft model bearing T-24 tumor cells without significant toxicity.

Enantioselective effect of chiral prothioconazole on the conformation of bovine serum albumin

As a typical chiral triazole fungicide, the enantioselective toxicity of prothioconazole to environmental organisms is of increasing concern. Herein, the binding mechanism of chiral PTCs to BSA was investigated by multi-spectral technique and molecular docking. Fluorescence titration and fluorescence lifetime experiments fully established that quenching BSA fluorescence by chiral PTCs is static quenching and could spontaneously bind to BSA. Hydrophobic interactions dominate the binding process of chiral PTCs to BSA. Differently, although both chiral PTCs and BSA have a primary binding site, the difference in chiral isomerism leads to a stronger binding ability of S-PTC than R-PTC. Both configurations of PTC can change the conformation of BSA and induce changes in the microenvironment around its amino acid residues, and the effect of S-PTC is more significant. Overall, S-PTC exhibited a more substantial effect on BSA structure relative to R-PTC. That is, S-PTC may lead to more potent potential toxicological effects on environmental organisms. This study provides a comprehensive assessment of the environmental behavior of chiral pesticides and their potential toxicity to environmental organisms at the molecular level and provides a theoretical basis for the screening of highly effective and biologically less toxic enantiomers of chiral pesticides.

Terpyridine Glycoconjugates and Their Metal Complexes: Antiproliferative Activity and Proteasome Inhibition

Metal terpyridine complexes have gained substantial interest in many application fields, such as catalysis and supramolecular chemistry. In recent years, the biological activity of terpyridine and its metal complexes has aroused considerable regard. On this basis, we synthesised new terpyridine derivatives of trehalose and glucose to improve the water solubility of terpyridine ligands and target them in cancer cells through glucose transporters. Glucose derivative and its copper(II) and iron(II) complexes showed antiproliferative activity. Interestingly, trehalose residue reduced the cytotoxicity of terpyridine. Moreover, we tested the ability of parent terpyridine ligands and their copper complexes to inhibit proteasome activity as an antineoplastic mechanism.

Design and Syntheses of Ruthenium ENE (E = S, Se) Pincer Complexes: A Versatile System for Catalytic and Biological Applications

This report describes synthesis of two ruthenium(II) ENE pincer complexes (E = S, C1 and E = Se, C2 ) by the reaction of bis(2-(phenylchalcogenyl)ethyl)amine ( L1 , L2 ) with RuCl 2 (PPh 3 ) 3 . The complexes were characterized with the help of 1 H and 13 C{ 1 H} NMR, FTIR, HRMS, cyclic voltammetry and elemental analysis techniques. The structure and bonding mode of ligand with ruthenium in C2 was established with the help of single crystal X-ray diffraction. The complex showed distorted octahedral geometry with two chlorine atoms trans to each other. The Ru-Se bond distances (Å) are 2.4564(3)-2.4630(3), Ru-N distance is 2.181(2), Ru-P distance is 2.2999(6), and Ru-Cl distances are 2.4078(6)-2.4314(6). The complexes showed good to excellent catalytic activity for the N -alkylation of 1,2-phenylenediamine with benzyl alcohol derivatives to synthesize 1,2-disubstituted benzimidazole derivatives. The complexes were also found to be efficient for aerobic oxidation of benzyl alcohols to corresponding aldehydes which are precursors to the bisimines generated in situ during the synthesis of 1,2-disubstituted benzimidazole derivatives. Complex C2 where selenium is coordinated with ruthenium was found to be more efficient as compared to sulfur coordinated ruthenium complex C1 . Since ruthenium complexes are getting increasing attention for developing new anticancer agents, the preliminary studies like binding behavior of both the complexes towards CT-DNA were studied by competitive binding with ethidium bromide (EthBr) using emission spectroscopy. In addition, the interactions of C1-C2 were also studied with bovine serum albumin (BSA) using steady state fluorescence quenching and synchronous fluorescence studies. A good stability of Ru(II) state was observed by cyclic voltammetric studies of C1-C2 . Overall these molecules are good examples of bio-organometallic systems for catalytic and biological applications.

Nuclease-like metalloscissors: Biomimetic candidates for cancer and bacterial and viral infections therapy

Despite the extensive and rapid discovery of modern drugs for treatment of cancer, microbial infections, and viral illnesses; these diseases are still among major global health concerns. To take inspiration from natural nucleases and also the therapeutic potential of metallopeptide antibiotics such as the bleomycin family, artificial metallonucleases with the ability of promoting DNA/RNA cleavage and eventually affecting cellular biological processes can be introduced as a new class of therapeutic candidates. Metal complexes can be considered as one of the main categories of artificial metalloscissors, which can prompt nucleic acid strand scission. Accordingly, biologists, inorganic chemists, and medicinal inorganic chemists worldwide have been designing, synthesizing and evaluating the biological properties of metal complexes as artificial metalloscissors. In this review, we try to highlight the recent studies conducted on the nuclease-like metalloscissors and their potential therapeutic applications. Under the light of the concurrent Covid-19 pandemic, the human need for new therapeutics was highlighted much more than ever before. The nuclease-like metalloscissors with the potential of RNA cleavage of invading viral pathogens hence deserve prime attention.

Terpyridine functionalized cyclodextrin nanoparticles: Metal coordination for tuning anticancer activity

Multi-metal and multi-cavity systems based on the coordination properties of tpy functionalizing cyclodextrin polymers were synthesized and characterized. Nanoparticles decorated with terpyridine derivatives via metal coordination showed high antiproliferative activity...

Terpyridines as promising antitumor agents: an overview of their discovery and development

INTRODUCTION

The fused aromatic system of terpyridines makes them good, innocent ligands for various metals. The resulting complexes have been extensively studied for both their biological activity and physico-chemical properties. However, although free ligands also have an interesting biological activity, their share in recent research is considerably limited.

AREAS COVERED

This review covers the literature on the anticancer activity of terpyridines with special attention being paid to their use as free ligands. Whenever possible, the mechanism of action has been discussed, thereby providing evidence of the substantial differences between sole ligands or less stable complexes and those that have heavier elements.

EXPERT OPINION

The existing literature indicates that there is a specific attitude for investigating terpyridines and their transition metal complexes. While the latter have been well explored and recognized in the scientific community, the free terpyridines are considered to be useful solely due to their complexing ability. At the same time, terpyridines could have similar or even higher anticancer potency than their complexes. Moreover, a mechanistic analysis of the stability and intracellular activity would provide information that would be useful for designing new drugs.

Synthesis, crystal structures, anticancer activities and molecular docking studies of novel thiazolidinone Cu(II) and Fe(III) complexes targeting lysosomes: special emphasis on their binding to DNA/BSA

Novel [CuL₂Cl]Cl·H₂O (1) and [FeL₂Cl₂]Cl·MeOH·CHCl₃·H₂O (2) complexes of (Z)-N'-((E)-3-methyl-4-oxothiazolidin-2-ylidene)picolinohydrazonamide (L) as antitumor agents were designed and synthesized in order to explore DNA and serum albumin interaction. X-ray diffraction revealed that both 1 and 2 were a triclinic crystal system with P1̄ space group, which consisted of a positive electric main unit, a negative chloride ion and some solvent molecules. The complexes with DNA and bovine serum albumin (BSA) were studied by fluorescence and electronic absorption spectrometry. The results indicated that there was moderate intercalative binding mode between the complexes and DNA with K_app values of 2.40 × 10⁵ M^-1 (1) and 6.49 × 10⁵ M^-1 (2). Agarose gel electrophoresis experiment showed that both 1 and 2 exhibited obvious DNA cleavage activity via an oxidative DNA damage pathway, and the cleavage activities of 1 were stronger than those of 2. Cytotoxicity assay showed that 1 had a more effective antitumor activity than 2. The two complexes were bound to BSA by a high affinity and quenched the fluorescence of BSA through a static mechanism. The thermodynamic parameters suggested that hydrophobic interactions played a key role in the binding process. The binding energy xpscore of 1 and 2 were -10.529 kcal mol^-1 and -10.826 kcal mol^-1 by docking studies, and this suggested that the binding process was spontaneous. Complex 1 displayed a lysosome-specific targeting behavior with a Pearson coefficient value of 0.82 by confocal laser scanning microscopy (CLSM), and accumulated in the lysosomes, followed by the disruption of lysosomal integrity.

Structure and biological profile of transition metal complexes with (E)-4-(2-(pyridin-2-ylmethylene)hydrazinyl)quinazoline

The interaction of the recently reported quinazoline derivative (E)-4-(2-(pyridin-2-ylmethylene)hydrazinyl)quinazoline (L) with a series of metal(II) (= copper(II), nickel(II), cobalt(II) and cadmium(II)) chlorides or nitrates resulted in the formation of mononuclear complexes which were characterized by spectroscopic techniques and single-crystal X-ray crystallography, i.e. [Cu(L)₂]Cl₂·4H₂O (1·4H₂O), [Ni(L)₂]Cl₂·4H₂O (2·4H₂O), [Ni(L)₂](NO₃)₂·MeOH (3·MeOH), [Co(L)₂]Cl₂·4H₂O (4·4H₂O), [Co(L)₂](NO₃)₂·H₂O (5·H₂O), [Co(L)₂](NO₃)₃·2.5H₂O (6·2.5H₂O), [Cd(L)(Cl)₂]·H₂O (7·H₂O) and [Cd(L)(CH₃OH)(H₂O)(NO₃)](NO₃) (8). The biological profile of the complexes was further assessed in regard to their binding affinity with calf-thymus DNA, their cleavage ability towards pBluescript II KS plasmid DNA in the absence or presence of irradiation of various wavelengths, their interaction with bovine serum albumin and finally, their ability to scavenge 1,1-diphenyl-picrylhydrazyl and 2,2΄-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) radicals and to reduce H₂O₂.

Copper(II) and iron(III) complexes of chiral dehydroabietic acid derived from natural rosin: metal effect on structure and cytotoxicity

A novel optically pure dinuclear copper(II) complex of a rosin derivative dehydroabietic acid (DHA, HL) was synthesized and fully characterized. The in vitro antitumor activities of the copper(II) complex Cu2(µ2-O)(L)4(DMF)2 (1) were explored and compared with those of a trinuclear iron(III) complex [Fe3(µ3-O)(L)6(CH3OH)2(CH3O)]·H2O (2). 1 was more cytotoxic than 2, and the in vitro cytotoxicity of 1 was comparable to that of cisplatin and oxaliplatin. The metal coordination improved the cytotoxicity of DHA. 1 could arrest cycle in G1 phase and induce apoptosis in MCF-7 cell. 1 increased reactive oxygen species level, GSSG/GSH ratio, and Ca2+ production, and caused the loss of mitochondrial membrane potential (Δψm) in MCF-7 cells. The up-regulated Bax and down-regulated Bcl-2 expression levels, caspase-9/caspase-3 activation, and the release of Cyt c demonstrate that 1 triggered mitochondria-mediated intrinsic apoptosis in MCF-7 cells. Caspase-8/caspase-4 activation and up-regulated Fas expression indicate that death receptor-mediated extrinsic apoptosis was included. Comet assay and up-regulated γ-H2AX and p53 expressions confirmed that 1 caused DNA damage in MCF-7 cells. Moreover, 1 led to enhancement of the biomarker of lipid peroxidation and the indicator of protein carbonylation in MCF-7 cells. All the results suggest that 1 could kill MCF-7 cells by generating oxidative stress, impairing DNA, promoting lipid peroxidation and protein carbonylation, and inducing apoptosis and autophagy. Furthermore, 1 also displayed antimetastatic activities with inhibition of cell invasion and migration, together with antiangiogenesis properties. On the whole, copper complex based on rosin derivatives is worth developing as metal-based antitumor drugs.

Role of π-conjugation on the coordination behaviour, substitution kinetics, DNA/BSA interactions, and in vitro cytotoxicity of carboxamide palladium(II) complexes

Treatments of N-(pyridin-2-ylmethyl)pyrazine-2-carboxamide (L1), N-(quinolin-8-yl)pyrazine-2-carboxamide (L2), N-(quinolin-8-yl)picolinamide (L3) and N-(quinolin-8-yl)quinoline-2-carboxamide (L4) with [PdCl2(NCMe)]2 afforded the corresponding Pd(ii) complexes, [Pd(L1)Cl] (PdL1); [Pd(L2)Cl] (PdL2); [Pd(L3)Cl] (PdL3); and [Pd(L4)Cl] (PdL4) in moderate yields. Structural characterisation of the compounds was achieved by NMR and FT-IR spectroscopies, elemental analyses and single crystal X-ray crystallography. The solid-state structures of complexes PdL2-PdL4 established the presence of one tridentate carboxamide and Cl ligands around the Pd(ii) coordination sphere, to give distorted square planar complexes. Electrochemical investigations of PdL1-PdL4 showed irreversible one-electron oxidation reactions. Kinetics reactivity of the complexes towards bio-molecules, thiourea (Tu), l-methionine (L-Met) and guanosine 5'-diphosphate disodium salt (5'-GMP) decreased in the order: PdL1 > PdL2 > PdL3 > PdL4, in tandem with the density functional theory (DFT) data. The complexes bind favourably to calf thymus (CT-DNA), and bovine serum albumin (BSA), and the order of their interactions agrees with the substitution kinetics trends. The in vitro cytotoxic activities of PdL1-PdL4 were examined in cancer cell lines A549, PC-3, HT-29, Caco-2, and HeLa, and a normal cell line, KMST-6. Overall, PdL1 and PdL3 displayed potent cytotoxic effects on A549, PC-3 HT-29 and Caco-2 comparable to cisplatin. All the investigated complexes exhibited lower toxicity on normal cells than cisplatin.

Development, evaluation and effect of anionic co-ligand on the biological activity of benzothiazole derived copper(II) complexes

Research on development of novel metal based anti-cancer agents continues with its popularity among bioinorganic community. Benzothiazole, an important heterocyclic pharmacophore, was chosen as a valuable and useful scaffold for the synthesis of novel copper(II) complexes. Three new copper(II) complexes obtained from the synthesis of newly synthesized benzothiazole based N-(benzo[d]thiazol-2-ylmethyl)-N-methyl-2-(pyridin-2-yl)ethan-1-amine (btzpy) ligand with CuCl₂ [Cu(btzpy)Cl₂] (1), Cu(NCS)₂ [Cu(btzpy)(NCS)₂] (2), and Cu(NO₃)₂ [Cu(btzpy)(NO₃)(H₂O)]NO₃ (3) were isolated and characterized by physical and spectroscopic measurements, including single-crystal X-ray structures. The interaction of complexes 1 and 3 with calf thymus (CT)-DNA was investigated using ethidium bromide fluorescence quenching assay and weak intercalation with K_SV values of 9.8 × 10² M^-1 and 8.2 × 10² M^-1, respectively was observed. All three complexes have shown DNA cleavage of supercoiled plasmid DNA forming single nicked and double nicked forms in the presence of external reducing agents like 3-mercaptopropionic acid (3-MPA) and ascorbic acid. The water-soluble complexes 1 and 3 also show prominent hydrolytic DNA cleavage. From the DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging assay, it was observed that complex 2 also exhibits good antioxidant properties. The cytotoxicity of complexes 1-3 was tested against the lung cancer cell line (A549) and complex 2 with -NCS moiety shows maximum activity in the micromolar range. A rationale for the observed activity is proposed in light of the other properties of these molecules.