New Oxidovanadium(IV) Coordination Complex Containing 2-Methylnitrilotriacetate Ligands Induces Cell Cycle Arrest and Autophagy in Human Pancreatic Ductal Adenocarcinoma Cell Lines

Trace elements in pancreatic cancer

BACKGROUND

Pancreatic cancer (PCA) is an extremely aggressive malignant cancer with an increasing incidence and a low five-year survival rate. The main reason for this high mortality is that most patients are diagnosed with PCA at an advanced stage, missing early treatment options and opportunities. As important nutrients of the human body, trace elements play an important role in maintaining normal physiological functions. Moreover, trace elements are closely related to many diseases, including PCA.

REVIEW

This review systematically summarizes the latest research progress on selenium, copper, arsenic, and manganese in PCA, elucidates their application in PCA, and provides a new reference for the prevention, diagnosis and treatment of PCA.

CONCLUSION

Trace elements such as selenium, copper, arsenic and manganese are playing an important role in the risk, pathogenesis, diagnosis and treatment of PCA. Meanwhile, they have a certain inhibitory effect on PCA, the mechanism mainly includes: promoting ferroptosis, inducing apoptosis, inhibiting metastasis, and inhibiting excessive proliferation.

Design, Synthesis, and Antitumor Evaluation of an Opioid Growth Factor Bioconjugate Targeting Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) presents a formidable challenge with high lethality and limited effective drug treatments. Its heightened metastatic potential further complicates the prognosis. Owing to the significant toxicity of current chemotherapeutics, compounds like [Met5]-enkephalin, known as opioid growth factor (OGF), have emerged in oncology clinical trials. OGF, an endogenous peptide interacting with the OGF receptor (OGFr), plays a crucial role in inhibiting cell proliferation across various cancer types. This in vitro study explores the potential anticancer efficacy of a newly synthesized OGF bioconjugate in synergy with the classic chemotherapeutic agent, gemcitabine (OGF-Gem). The study delves into assessing the impact of the OGF-Gem conjugate on cell proliferation inhibition, cell cycle regulation, the induction of cellular senescence, and apoptosis. Furthermore, the antimetastatic potential of the OGF-Gem conjugate was demonstrated through evaluations using blood platelets and AsPC-1 cells with a light aggregometer. In summary, this article demonstrates the cytotoxic impact of the innovative OGF-Gem conjugate on pancreatic cancer cells in both 2D and 3D models. We highlight the potential of both the OGF-Gem conjugate and OGF alone in effectively inhibiting the ex vivo pancreatic tumor cell-induced platelet aggregation (TCIPA) process, a phenomenon not observed with Gem alone. Furthermore, the confirmed hemocompatibility of OGF-Gem with platelets reinforces its promising potential. We anticipate that this conjugation strategy will open avenues for the development of potent anticancer agents.

Effect of the extra-nuclear cation on the cytotoxicity and mechanism of action of pyridine-2,6-dicarboxylate Ga(III) complexes

Two Ga(III) complexes (C1) and (C2) were prepared by the one-pot reaction of pyridine-2,6-dicarboxylic acid and aminopyridine derivatives with gallium(III) nitrate octahydrate. The compounds were characterized by single-crystal X-ray diffraction. The distorted octahedral geometry was confirmed by crystallographic data for both complexes. The study of the in vitro cytotoxicity of the compounds showed that the presence of different extra-nuclear cations can affect the cytotoxicity of the same anionic complexes. The most significant antiproliferative activity was observed for C1 (IC50 = 0.69 μM, MAE = 73.96%) and C2 (IC50 = 3.78 μM, MAE = 60.35%) (where MAE represents the maximal antiproliferative effect) against A431 cell line. The mechanistic study evidenced the same pathway for the death of A431 cells treated with the complexes, although the results for C2 were obtained at approximately five times the concentration of C1. According to the study, both complexes induced cell cycle arrest in G2/M phase in A431 cells by upregulating the levels of p21, p27, p-cdc25C, and p-cdc2 and downregulating the levels of cdc25C, cdc2, and cyclin B1. In addition, apoptosis via a caspase-dependent mitochondrial pathway was confirmed by a decrease in Bcl-2 family proteins and an increase in the expression of procaspase-9 and 3. Also, the complexes induced autophagic cell death by activating the RAGE /PI3KC3/Beclin 1 pathway in A431 cells. DATA AVAILABILITY: CCDC 874052 and 874055 contain the supplementary crystallographic data for C1 and C2, respectively. These data can be obtained free of charge via http://www.ccdc.cam.ac.uk/services/structures?pid=ccdc:874052,874055&sid=CCDCManual, or from the Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ, UK; fax: (+44) 1223-336-033; or e-mail: deposit@ccdc.cam.ac.uk.

Metal-Based Anticancer Complexes and p53: How Much Do We Know?

P53 plays a key role in protecting the human genome from DNA-related mutations; however, it is one of the most frequently mutated genes in cancer. The P53 family members p63 and p73 were also shown to play important roles in cancer development and progression. Currently, there are various organic molecules from different structural classes of compounds that could reactivate the function of wild-type p53, degrade or inhibit mutant p53, etc. It was shown that: (1) the function of the wild-type p53 protein was dependent on the presence of Zn atoms, and (2) Zn supplementation restored the altered conformation of the mutant p53 protein. This prompted us to question whether the dependence of p53 on Zn and other metals might be used as a cancer vulnerability. This review article focuses on the role of different metals in the structure and function of p53, as well as discusses the effects of metal complexes based on Zn, Cu, Fe, Ru, Au, Ag, Pd, Pt, Ir, V, Mo, Bi and Sn on the p53 protein and p53-associated signaling.

Evaluation of autophagy inhibition to combat cancer: (vanadium complex)-protein interactions, parameterization, and validation of a new force field

Autophagy has drawn attention from the scientific community, mainly because of its significant advantages over chemotherapeutic processes. One of these advantages is its direct action on cancer cells, avoiding possible side effects, unlike chemotherapy, which reaches tumor cells and affects healthy cells in the body, leading to a great loss in the quality of life of patients. In this way, it is known that vanadium complex (VC) [VO(oda)(phen)] has proven inhibition effect on autophagy process in pancreatic cancer cells. Keeping that in mind, molecular dynamics (MD) simulations can be considered excellent strategies to investigate the interaction of metal complexes and their biological targets. However, simulations of this type are strongly dependent on the appropriate choice of force field (FF). Therefore, this work proposes the development of AMBER FF parameters for VC, having a minimum energy structure as a starting point, obtained through DFT calculations with B3LYP/def2-TZVP level of theory plus ECP for the vanadium atom. An MD simulation in vacuum was performed to validate the developed FF. From the structural analyses, satisfying values of VC bond lengths and angles were obtained, where a good agreement with the experimental data and the quantum reference was found. The RMSD analysis showed an average of only 0.3%. Finally, we performed docking and MD (120 ns) simulations with explicit solvent between VC and PI3K. Overall, our findings encourage new parameterizations of metal complexes with significant biological applications, as well as allow to contribute to the elucidation of the complex process of autophagy.

Biological Consequences of Vanadium Effects on Formation of Reactive Oxygen Species and Lipid Peroxidation

Lipid peroxidation (LPO), a process that affects human health, can be induced by exposure to vanadium salts and compounds. LPO is often exacerbated by oxidation stress, with some forms of vanadium providing protective effects. The LPO reaction involves the oxidation of the alkene bonds, primarily in polyunsaturated fatty acids, in a chain reaction to form radical and reactive oxygen species (ROS). LPO reactions typically affect cellular membranes through direct effects on membrane structure and function as well as impacting other cellular functions due to increases in ROS. Although LPO effects on mitochondrial function have been studied in detail, other cellular components and organelles are affected. Because vanadium salts and complexes can induce ROS formation both directly and indirectly, the study of LPO arising from increased ROS should include investigations of both processes. This is made more challenging by the range of vanadium species that exist under physiological conditions and the diverse effects of these species. Thus, complex vanadium chemistry requires speciation studies of vanadium to evaluate the direct and indirect effects of the various species that are present during vanadium exposure. Undoubtedly, speciation is important in assessing how vanadium exerts effects in biological systems and is likely the underlying cause for some of the beneficial effects reported in cancerous, diabetic, neurodegenerative conditions and other diseased tissues impacted by LPO processes. Speciation of vanadium, together with investigations of ROS and LPO, should be considered in future biological studies evaluating vanadium effects on the formation of ROS and on LPO in cells, tissues, and organisms as discussed in this review.

Regulated cell death (RCD) in cancer: key pathways and targeted therapies

Regulated cell death (RCD), also well-known as programmed cell death (PCD), refers to the form of cell death that can be regulated by a variety of biomacromolecules, which is distinctive from accidental cell death (ACD). Accumulating evidence has revealed that RCD subroutines are the key features of tumorigenesis, which may ultimately lead to the establishment of different potential therapeutic strategies. Hitherto, targeting the subroutines of RCD with pharmacological small-molecule compounds has been emerging as a promising therapeutic avenue, which has rapidly progressed in many types of human cancers. Thus, in this review, we focus on summarizing not only the key apoptotic and autophagy-dependent cell death signaling pathways, but the crucial pathways of other RCD subroutines, including necroptosis, pyroptosis, ferroptosis, parthanatos, entosis, NETosis and lysosome-dependent cell death (LCD) in cancer. Moreover, we further discuss the current situation of several small-molecule compounds targeting the different RCD subroutines to improve cancer treatment, such as single-target, dual or multiple-target small-molecule compounds, drug combinations, and some new emerging therapeutic strategies that would together shed new light on future directions to attack cancer cell vulnerabilities with small-molecule drugs targeting RCD for therapeutic purposes.

Acute Toxicity Evaluation of Non-Innocent Oxidovanadium(V) Schiff Base Complex

The vanadium(V) complexes have been investigated as potential anticancer agents which makes it essential to evaluate their toxicity for safe use in the clinic. The large-scale synthesis and the acute oral toxicity in mice of the oxidovanadium(V) Schiff base catecholate complex, abbreviated as [VO(HSHED)dtb] containing a redox-active ligand with tridentate Schiff base (HSHED = N-(salicylideneaminato)-N’-(2-hydroxyethyl)-1,2-ethylenediamine) and dtb = 3,5-di-(t-butyl)catechol ligands were carried out. The body weight, food consumption, water intake as well biomarkers of liver and kidney toxicity of the [VO(HSHED)dtb] were compared to the precursors, sodium orthovanadate, and free ligand. The 10-fold scale-up synthesis of the oxidovanadium(V) complex resulting in the preparation of material in improved yield leading to 2–3 g (79%) material suitable for investigating the toxicity of vanadium complex. No evidence of toxicity was observed in animals when acutely exposed to a single dose of 300 mg/kg for 14 days. The toxicological results obtained with biochemical and hematological analyses did not show significant changes in kidney and liver parameters when compared with reference values. The low oral acute toxicity of the [VO(HSHED)dtb] is attributed to redox chemistry taking place under biological conditions combined with the hydrolytic stability of the oxidovanadium(V) complex. These results document the design of oxidovanadium(V) complexes that have low toxicity but still are antioxidant and anticancer agents.

The liposomal delivery of hydrophobic oxidovanadium complexes imparts highly effective cytotoxicity and differentiating capacity in neuroblastoma tumour cells

Oxidovanadium complexes with organic ligands are well known to have cytotoxic or differentiating capabilities against a range of cancer cell types. Their limited use in clinical testing though has resulted largely from uncertainties about the long-term toxicities of such complexes, due in part to the speciation to vanadate ions in the circulation. We hypothesised that more highly stable complexes, delivered using liposomes, may provide improved opportunities for oxidovanadium applications against cancer. In this study we sourced specifically hydrophobic forms of oxidovanadium complexes with the explicit aim of demonstrating liposomal encapsulation, bioavailability in cultured neuroblastoma cells, and effective cytotoxic or differentiating activity. Our data show that four ethanol-solubilised complexes with amine bisphenol, aminoalcohol bisphenol or salan ligands are equally or more effective than a previously used complex bis(maltolato)oxovanadium(V) in neuroblastoma cell lines. Moreover, we show that one of these complexes can be stably incorporated into cationic liposomes where it retains very good bioavailability, apparently low speciation and enhanced efficacy compared to ethanol delivery. This study provides the first proof-of-concept that stable, hydrophobic oxidovanadium complexes retain excellent cellular activity when delivered effectively to cancer cells with nanotechnology. This offers the improved prospect of applying oxidovanadium-based drugs in vivo with increased stability and reduced off-target toxicity.

Vanadium: Risks and possible benefits in the light of a comprehensive overview of its pharmacotoxicological mechanisms and multi-applications with a summary of further research trends

BACKGROUND

Vanadium (V) is an element with a wide range of effects on the mammalian organism. The ability of this metal to form organometallic compounds has contributed to the increase in the number of studies on the multidirectional biological activity of its various organic complexes in view of their application in medicine.

OBJECTIVE

This review aims at summarizing the current state of knowledge of the pharmacological potential of V and the mechanisms underlying its anti-viral, anti-bacterial, anti-parasitic, anti-fungal, anti-cancer, anti-diabetic, anti-hypercholesterolemic, cardioprotective, and neuroprotective activity as well as the mechanisms of appetite regulation related to the possibility of using this element in the treatment of obesity. The toxicological potential of V and the mechanisms of its toxic action, which have not been sufficiently recognized yet, as well as key information about the essentiality of this metal, its physiological role, and metabolism with certain aspects on the timeline is collected as well. The report also aims to review the use of V in the implantology and industrial sectors emphasizing the human health hazard as well as collect data on the directions of further research on V and its interactions with Mg along with their character.

RESULTS AND CONCLUSIONS

Multidirectional studies on V have shown that further analyses are still required for this element to be used as a metallodrug in the fight against certain life-threatening diseases. Studies on interactions of V with Mg, which showed that both elements are able to modulate the response in an interactive manner are needed as well, as the results of such investigations may help not only in recognizing new markers of V toxicity and clarify the underlying interactive mechanism between them, thus improving the medical application of the metals against modern-age diseases, but also they may help in development of principles of effective protection of humans against environmental/occupational V exposure.

A novel coordination complex of platinum (PT) induces cell death in colorectal cancer by altering redox balance and modulating MAPK pathway

Background

Colorectal cancer (CRC) is a heterogeneous tumor having various genetic alterations. The current treatment options had limited impact on disease free survival due to therapeutic resistance. Novel anticancer agents are needed to treat CRC specifically metastatic colorectal cancer. A novel coordination complex of platinum, (salicylaldiminato)Pt(II) complex with dimethylpropylene linkage (PT) exhibited potential anti-cancer activity. In this study, we explored the molecular mechanism of PT-induced cell death in colorectal cancer.

Methods

Colony formation was evaluated using the clonogenic assay. Apoptosis, cell cycle analysis, reactive oxygen species, mitochondrial membrane potential and caspase-3/− 7 were assessed by flow cytometry. Glutathione level was detected by colorimetric assay. PT-induced alteration in pro-apoptotic/ anti-apoptotic proteins and other signaling pathways were investigated using western blotting. P38 downregulation was performed using siRNA.

Results

In the present study, we explored the molecular mechanism of PT-mediated inhibition of cell proliferation in colorectal cancer cells. PT significantly inhibited the colony formation in human colorectal cancer cell lines (HT-29, SW480 and SW620) by inducing apoptosis and necrosis. This platinum complex was shown to significantly increase the reactive oxygen species (ROS) generation, depletion of glutathione and reduced mitochondrial membrane potential in colorectal cancer cells. Exposure to PT resulted in the downregulation of anti-apoptotic proteins (Bcl2, BclxL, XIAP) and alteration in Cyclins expression. Furthermore, PT increased cytochrome c release into cytosol and enhanced PARP cleavage leading to activation of intrinsic apoptotic pathway. Moreover, pre-treatment with ROS scavenger N-acetylcysteine (NAC) attenuated apoptosis suggesting that PT-induced apoptosis was driven by oxidative stress. Additionally, we show that PT-induced apoptosis was mediated by activating p38 MAPK and inhibiting AKT pathways. This was demonstrated by using chemical inhibitor and siRNA against p38 kinase which blocked the cytochrome c release and apoptosis in colorectal cancer cells.

Conclusion

Collectively, our data demonstrates that the platinum complex (PT) exerts its anti-proliferative effect on CRC by ROS-mediated apoptosis and activating p38 MAPK pathway. Thus, our findings reveal a novel mechanism of action for PT on colorectal cancer cells and may have therapeutic implication.

Cell apoptosis induced by ciprofloxacin based Cu(II) complexes: cytotoxicity, SOD mimic and antibacterial studies

The current cancer research focuses on the design and synthesis of chemical compounds that can modulate cell apoptosis or programmed cell death. So we synthesized and characterized ciprofloxacin based copper(II) complexes and studied their anticancer activity against HCT 116 cancer cells by MTT assay. We further investigated the influence of compound-2 (better IC₅₀ value than cisplatin) on cancer cells to know the exact mechanism of anticancer activity. The distinct morphological change of cells due to compound-2 was observed in bright field microscopy. The trypan blue assay clearly demonstrated inhibition of cell viability. The clonogenic ability inhibition assay showed a low percentage of the plating efficiency of HCT 116 cells. The mechanism of cell death, either apoptotic or necrotic was distinguished by annexin V-FITC/PI (propidium iodide) staining assay and LDH (lactate dehydrogenase) release assay. The positive annexinV/PI cells in presence of compound-2 and absence of LDH in the LDH release assay confirmed the cell apoptotic mechanism of cell death. We also checked in vitro antibacterial activity of compounds against Gram^(-ve) and Gram^(+ve) bacteria in terms of MIC (minimum inhibitory concentration) and the data were in good agreement with the standard drug data. SOD mimic activity of synthesized Cu(II) complexes was also studied in terms of IC₅₀ value. The brine shrimp lethality bioassay was also performed to evaluate the cytotoxic properties of the Cu(II) complexes.Communicated by Ramaswamy H. Sarma.

Molecular and Cellular Mechanisms of Cytotoxic Activity of Vanadium Compounds against Cancer Cells

Discovering that metals are essential for the structure and function of biomolecules has given a completely new perspective on the role of metal ions in living organisms. Nowadays, the design and synthesis of new metal-based compounds, as well as metal ion binding components, for the treatment of human diseases is one of the main aims of bioinorganic chemistry. One of the areas in vanadium-based compound research is their potential anticancer activity. In this review, we summarize recent molecular and cellular mechanisms in the cytotoxic activity of many different synthetic vanadium complexes as well as inorganic salts. Such mechanisms shall include DNA binding, oxidative stress, cell cycle regulation and programed cell death. We focus mainly on cellular studies involving many type of cancer cell lines trying to highlight some new significant advances.

Synthesis, Characterisation, and Biological Properties of Oxidovanadium(IV) 3,5-Dinitrosalicylhydroxamate Complexes

The new oxidovanadium(iv) complexes of composition [VO(3,5(NO2)2C6H2(OH)CONHO)2] 1 and [VO(acac)(3,5(NO2)2C6H2(OH)CONHO)] 2 (where acac=(CH3COCHCOCH3)–] have been synthesised by the reactions of VOSO4·5H2O and [VO(acac)2] with potassium 3,5-dinitrosalicylhydroxamate (3,5-(NO2)2SHK) and characterised by elemental analyses, molar conductivity, magnetic moment measurements and FT-IR, UV-vis, and electron spin resonance (ESR) spectroscopies and mass spectrometry. Infrared spectra of complexes have indicated bonding through oxygen atoms of carbonyl and hydroxamic groups (O,O coordination). The magnetic moment, ESR, and mass spectra of the complexes suggested their monomeric nature, and a distorted square-pyramidal geometry around the vanadium has tentatively been proposed. The electrochemical behaviour of 1 and 2 has been studied by cyclic voltammetry. Thermal behaviour of the complexes studied by thermogravimetric and differential thermal analysis techniques has yielded VO2 as the decomposition product. The invitro antimicrobial activity of the ligand and complexes has been assayed against pathogenic bacteria and fungi by the minimum inhibitory concentration (MIC) method. The invitro antioxidant activity of the complexes has been determined by 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging method.

The Role of Autophagy in Pancreatic Cancer-Recent Advances

Pancreatic ductal adenocarcinoma (PDAC) remains one of the deadliest cancers with a 5-year survival rate of only 9%, despite ongoing efforts to improve treatment. This dismal prognosis is due to the difficulty of early stage diagnosis, drug resistance, and likelihood of metastasis development. It is therefore of great importance to identify appropriate therapeutic targets and gain a greater understanding of PDAC biology. Autophagy is a membrane-mediated degradation and recycling mechanism, which is crucial for cell homeostasis. There is evidence for both a tumor-suppressive and a tumor-promoting role of autophagy in cancer, and this is likely context dependent. Within PDAC, a large body of evidence points towards autophagy being required for tumor survival and metabolism. In this review, we describe the recent advances in the understanding of the role and regulation of autophagy in PDAC.

Fast, Facile and Solvent-Free Dry-Melt Synthesis of Oxovanadium(IV) Complexes: Simple Design with High Potency towards Cancerous Cells

A range of oxobis(phenyl-1,3-butanedione) vanadium(IV) complexes have been successfully synthesized from cheap starting materials and a simple and solvent-free one-pot dry-melt reaction. This direct, straightforward, fast and alternative approach to inorganic synthesis has the potential for a wide range of applications. Analytical studies confirm their successful synthesis, purity and solid-state coordination, and we report the use of such complexes as potential drug candidates for the treatment of cancer. After a 24 hour incubation of A549 lung carcinoma cells with the compounds, they reveal cytotoxicity values elevenfold greater than cisplatin and remain non-toxic towards normal cell types. Additionally, the complexes are stable over a range of physiological pH values and show the potential for interactions with bovine serum albumin.