Selective cytotoxicity of vanadium complexes on human pancreatic ductal adenocarcinoma cell line by inducing necroptosis, apoptosis and mitotic catastrophe process

Catalytic, Antifungal, and Antiproliferative Activity Studies of a New Family of Mononuclear [VIVO]/[VVO2] Complexes

Ligands derived from 2-(1-phenylhydrazinyl)pyridine and salicylaldehyde (HL1), 3-methoxysalicylaldehyde (HL2), 5-bromosalicylaldehyde (HL3), and 3,5-di-tert-butylsalicylaldehyde (HL4) react with [VIVO(acac)2] in MeOH followed by aerial oxidation to give [VVO2(L1)] (1), [VVO2(L2)] (2), [VVO2(L3)] (3), and [VVO2(L4)] (4). Complex [VIVO(acac)(L1)] (5) is also isolable from [VIVO(acac)2] and HL1 in dry MeOH. Structures of all complexes were confirmed by single-crystal X-ray and spectroscopic studies. They efficiently catalyze benzyl alcohol and its derivatives' oxidation in the presence of H2O2 to their corresponding aldehydes. Under optimized reaction conditions using 1 as a catalyst precursor, conversion of benzyl alcohol follows the order: 4 (93%) > 2 (90%) > 1 (86%) > 3 (84%) ≈ 5 (84%). These complexes were also evaluated for antifungal and antiproliferative activities. Complex 3 with MIC50 = 16 μg/mL, 4 with MIC50 = 12 μg/mL, and 5 with MIC50 = 16 μg/mL are efficient toward planktonic cells of Candida albicans and Candida tropicalis. On Michigan cancer foundation-7 (MCF-7) cells, they show comparable cytotoxic effects and exhibit IC50 in the 27.3-33.5 μg/mL range, and among these, 4 exhibits the highest cytotoxicity. A similar study on human embryonic kidney cells (HEK293) confirms their less toxicity at lower concentrations (4 to 16 μg/mL) compared to MCF-7.

Sodium orthovanadate exhibits anti-angiogenic, antiapoptotic and blood glucose-lowering effect on colon cancer associated with diabetes

BACKGROUND

The presence of type 2 diabetes mellitus increases the risk of developing the colon cancer. The main objective of this study was to determine the role of sodium orthovanadate (SOV) in colon cancer associated with diabetes mellitus by targeting the competitive inhibition of PTP1B.

METHODS

For in vivo study, high fat diet with low dose streptozotocin model was used for inducing the diabetes mellitus. Colon cancer was induced by injecting 1,2-dimethylhydrazine (25 mg/kg, sc) twice a week. TNM staging and immunohistochemistry (IHC) was carried out for colon cancer tissues. In vitro studies like MTT assay, clonogenic assay, rhodamine-123 dye assay and annexin V-FITC assay using flow cytometry were performed on HCT-116 cell line. CAM assay was performed to examine the anti-angiogenic effect of the drug.

RESULTS

Sodium orthovanadate reduces the blood glucose level and tumor parameters in the animals. In vitro studies revealed that SOV decreased cell proliferation dose dependently. In addition, SOV induced apoptosis as depicted from rhodamine-123 dye assay and annexin V-FITC assay using flow cytometry as well as p53 IHC staining. SOV showed reduced angiogenesis effect on eggs which was depicted from CAM assay and also from CD34 and E-cadherin IHC staining.

CONCLUSIONS

Our data suggest that SOV exhibits protective role in colon cancer associated with diabetes mellitus. SOV exhibits anti-proliferative, anti-angiogenic and apoptotic inducing effects hence can be considered for therapeutic switching in diabetic colon cancer.

Genome, Metabolism, or Immunity: Which Is the Primary Decider of Pancreatic Cancer Fate through Non-Apoptotic Cell Death?

Pancreatic ductal adenocarcinoma (PDAC) is a solid tumor characterized by poor prognosis and resistance to treatment. Resistance to apoptosis, a cell death process, and anti-apoptotic mechanisms, are some of the hallmarks of cancer. Exploring non-apoptotic cell death mechanisms provides an opportunity to overcome apoptosis resistance in PDAC. Several recent studies evaluated ferroptosis, necroptosis, and pyroptosis as the non-apoptotic cell death processes in PDAC that play a crucial role in the prognosis and treatment of this disease. Ferroptosis, necroptosis, and pyroptosis play a crucial role in PDAC development via several signaling pathways, gene expression, and immunity regulation. This review summarizes the current understanding of how ferroptosis, necroptosis, and pyroptosis interact with signaling pathways, the genome, the immune system, the metabolism, and other factors in the prognosis and treatment of PDAC.

Vanadium complex as a potential modulator of the autophagic mechanism through proteins PI3K and ULK1: development, validation and biological implications of a specific force field for [VO(bpy)2Cl]

The modulation of autophagy has been presented as a very useful strategy in anticancer treatments. In this sense, the vanadium complex (VC) bis(2,2'-bipyridine)chlorooxovanadium(IV), [VO(bpy)2Cl], is known for its ability to induce autophagy in triple-negative breast cancer cells (TNBC). An excellent resource to investigate the role of VC in the induction of autophagy is to make use of Molecular Dynamics (MD) simulations. However, until now, the scarcity of force field parameters for the VC prevented a reliable analysis. The autophagy signaling pathway starts with the PI3K protein and ends with ULK1. Therefore, in the first stage of this work, we developed a new AMBER force field for the VC (VCFF) from a quantum structure, obtained by DFT calculations. In the second stage, the VCFF was validated through structural analyses. From this, it was possible to investigate, through docking and MD (200 ns), the performance of the PI3K-VC and ULK1-VC systems (third stage). The analyses of this last stage involved RMSD, hydrogen bonds, RMSF and two pathways for the modulation of autophagy. In general, this work fills in the absence of force field parameters (FF) for VC by proposing an efficient and new FF, in addition to investigating, at the molecular level, how VC is able to induce autophagy in TNBC cells. This study encourages new parameterizations of metallic complexes and contributes to the understanding of the duality of autophagic processes.Communicated by Ramaswamy H. Sarma.

In Vitro and In Vivo Biological Activities of Dipicolinate Oxovanadium(IV) Complexes

The work is focused on anticancer properties of dipicolinate (dipic)-based vanadium(IV) complexes [VO(dipic)(N^∩N)] bearing different diimines (2-(1H-imidazol-2-yl)pyridine, 2-(2-pyridyl)benzimidazole, 1,10-phenanthroline-5,6-dione, 1,10-phenanthroline, and 2,2'-bipyridine), as well as differently 4,7-substituted 1,10-phenanthrolines. The antiproliferative effect of V(IV) systems was analyzed in different tumors (A2780, HCT116, and HCT116-DoxR) and normal (primary human dermal fibroblasts) cell lines, revealing a high cytotoxic effect of [VO(dipic)(N^∩N)] with 4,7-dimethoxy-phen (5), 4,7-diphenyl-phen (6), and 1,10-phenanthroline (8) against HCT116-DoxR cells. The cytotoxicity differences between these complexes can be correlated with their different internalization by HCT116-DoxR cells. Worthy of note, these three complexes were found to (i) induce cell death through apoptosis and autophagy pathways, namely, through ROS production; (ii) not to be cytostatic; (iii) to interact with the BSA protein; (iv) do not promote tumor cell migration or a pro-angiogenic capability; (v) show a slight in vivo anti-angiogenic capability, and (vi) do not show in vivo toxicity in a chicken embryo.

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.

Calcium silicate/bortezomib combinatory therapy for multiple myeloma

Multiple myeloma (MM) is the second most common hematologic malignancy. Bortezomib (BOR), a first-generation proteasome inhibitor, is the basic agent for the treatment of MM and has greatly improved the survival of patients with MM. However, the side effects of BOR (e.g. peripheral neuropathy) occur frequently and almost all MM patients eventually develop resistance to BOR and go on to develop refractory relapsed multiple myeloma (RRMM). Therefore, it is of great significance to find a method to increase the sensitivity of MM to BOR to reduce toxicity and drug resistance. Herein, we found that calcium silicate (CS), a silicate bioceramic that releases Si ions (SIs), enhanced the BOR anti-myeloma effect in vitro in human myeloma cell lines (HMCLs), including BOR-resistant cell lines (U266/BOR). The enhanced anti-myeloma effect of these two agents was demonstrated in primary MM cells regardless of disease status and in MM xenograft mice. Mechanistically, SI enhanced G2/M cell cycle arrest and the inhibition of the NF-κB pathway induced by BOR. These results imply that the combination of SI and BOR (SI/BOR) is a promising way to overcome BOR resistance in MM and RRMM. The future use of nanotechnology to prepare CS nanomaterials as BOR carriers for the treatment of MM and RRMM is a very promising clinical application.

Simvastatin Attenuated Tumor Growth in Different Pancreatic Tumor Animal Models

Newly diagnosed pancreatic cancer increases year by year, while the prognosis of pancreatic cancer has not been very good. Statin drugs were found to have protective effects against a variety of cancers, but their association with pancreatic cancer remains to be clarified. This study used different pancreatic cancer cell lines and in different animal models to confirm the relationship between simvastatin and pancreatic cancer. Flow cytometry and luciferase-based bioluminescent images were used to investigate the cell cycle and tumor growth changes under simvastatin treatment. Simvastatin decreased the MIA PaCa-2 cells, PANC-1 cells, and BxPC-3 cell viability significantly and may arrest the cell cycle in the G0 phase. During in vivo study, subcutaneously implanted simvastatin pre-treated pancreatic cancer cells and intraperitoneally treated simvastatin continuously demonstrated a slower tumor growth rate and decreased the tumor/body weight ratio significantly. In intravenous implant models, implanted simvastatin-pre-treated BxPC-3 cells and cells treated along with simvastatin significantly decreased the tumor growth curve. Implanting the simvastatin-pre-treated pancreatic cells in the subcutaneous model showed better growth inhibition than the intravenous model. These results suggest simvastatin treatment may relate to different signaling pathways in local growth and metastasis. Pancreatic cancer cells presented different growth patterns in different animal-induced models, which could be important for clinical reference when it comes to the relationship of long-term statin use and pancreatic cancer.

A novel necroptosis-related gene signature associated with immune landscape for predicting the prognosis of papillary thyroid cancer

Background: Necroptosis, a type of programmed cell death, has been implicated in a variety of cancer-related biological processes. However, the roles of necroptosis-related genes in thyroid cancer yet remain unknown.

Methods: A necroptosis-related gene signature was constructed using the least absolute shrinkage and selection operator (LASSO) regression analysis and Cox regression analysis. The predictive value of the prognostic signature was validated in an internal cohort. Additionally, the single-sample gene set enrichment analysis (ssGSEA) was used to examine the relationships between necroptosis and immune cells, immunological functions, and immune checkpoints. Next, the modeled genes expressions were validated in 96 pairs of clinical tumor and normal tissue samples. Finally, the effects of modeled genes on PTC cells were studied by RNA interference approaches in vitro.

Results: In this study, the risk signature of seven necroptosis-related genes was created to predict the prognosis of papillary thyroid cancer (PTC) patients, and all patients were divided into high- and low-risk groups. Patients in the high-risk group fared worse in terms of overall survival than those in the low-risk group. The area under the curve (AUC) of the receiving operating characteristic (ROC) curves proved the predictive capability of created signature. The risk score was found to be an independent risk factor for prognosis in multivariate Cox analysis. The low-risk group showed increased immune cell infiltration and immunological activity, implying that they might respond better to immune checkpoint inhibitor medication. Next, GEO database and qRT-PCR in 96 pairs of matched tumorous and non-tumorous tissues were used to validate the expression of the seven modeled genes in PTCs, and the results were compatible with TCGA database. Finally, overexpression of IPMK, KLF9, SPATA2 could significantly inhibit the proliferation, invasion and migration of PTC cells.

Conclusion: The created necroptosis associated risk signature has the potential to have prognostic capability in PTC for patient outcome. The findings of this study could pave the way for further research into the link between necroptosis and tumor immunotherapy.

The Role of Nonapoptotic Programmed Cell Death — Ferroptosis, Necroptosis, and Pyroptosis — in Pancreatic Ductal Adenocarcinoma Treatment

Pancreatic ductal adenocarcinoma (PDAC) is the most lethal cancer, with a dismal 5-year survival rate of less than 10%. It is estimated that approximately 80% of pancreatic ductal carcinoma (PDAC) patients are diagnosed at an advanced or metastatic stage. Hence, most patients are not appropriate candidates for surgical resection and therefore require systemic chemotherapy. However, it has been reported that most patients develop chemoresistance within several months, partly because of antiapoptotic mechanisms. Hence, inducing alternative programmed cell death (PCD), including ferroptosis, necroptosis or pyroptosis, seems to be a promising strategy to overcome antiapoptosis-mediated chemoresistance. In this review, we shed light on the molecular mechanisms of ferroptosis, necroptosis and pyroptosis and suggest several potential strategies (e.g., compounds and nanoparticles [NPs]) that are capable of triggering nonapoptotic PCD to suppress PDAC progression. In conclusion, these strategies might serve as adjuvants in combination with clinical first-line chemotherapies to improve patient survival rates.

Novel necroptosis-related gene signature for predicting the prognosis of pancreatic adenocarcinoma

Pancreatic adenocarcinoma (PAAD) is a deadly digestive system tumor with a poor prognosis. Recently, necroptosis has been considered as a type of inflammatory programmed cell death. However, the expression of necroptosis-related genes (NRGs) in PAAD and their associations with prognosis remain unclear. NRGs' prediction potential in PAAD samples from The TCGA and GEO datasets was investigated. The prediction model was constructed using Lasso regression. Co-expression analysis showed that gene expression was closely related to necroptosis. NRGs were shown to be somewhat overexpressed in high-risk people even when no other clinical symptoms were present, indicating that they may be utilized in a model to predict PAAD prognosis. GSEA showed immunological and tumor-related pathways in the high-risk group. Based on the findings, immune function and m6A genes differ significantly between the low-risk and high-risk groups. MET, AM25C, MROH9, MYEOV, FAM111B, Y6D, and PPP2R3A might be related to the oncology process for PAAD patients. Moreover, CASKIN2, TLE2, USP20, SPRN, ARSG, MIR106B, and MIR98 might be associated with low-risk patients with PAAD. NRGs and the relationship of the immune function, immune checkpoints, and m6A gene expression with NRGs in PAAD may be considered as potential therapeutic targets that should be further studied.

The Effect of Vanadium Inhalation on the Tumor Progression of Urethane-Induced Lung Adenomas in a Mice Model

Lung cancer has the highest death rates. Aerosol drug delivery has been used for other lung diseases. The use of inhaled vanadium (V) as an option for lung cancer treatment is explored. Four groups of mice were studied: (1) Saline inhalation alone, (2) Single intraperitoneal (i.p.) dose of urethane, (3) V nebulization twice a week (Wk) for 8 Wk, and (4) A single dose of urethane and V nebulization for 8 Wk. Mice were sacrificed at the end of the experiment. Number and size of tumors, PCNA (proliferating cell nuclear antigen) and TUNEL (terminal deoxynucleotidyl tranferase dUTP nick-end labeling) immunohistochemistry were evaluated and compared within groups. Results: The size and number of tumors decreased in mice exposed to V-urethane and the TUNEL increased in this group; differences in the PCNA were not observed. Conclusions: Aerosol V delivery increased apoptosis and possibly the growth arrest of the tumors with no respiratory clinical changes in the mice.

Compound Cocktail Inhibits Influenza Viral Pneumonia via Phospholipase Cγ1 Phosphorylation-Related Necroptosis and Partial Autophagy in Natural Killer Cells

Influenza viral infections are prone to global outbreaks and cause pneumonia in affected populations. High morbidity and mortality caused by pneumonia occur during an influenza pandemic. Antivirals or control of inflammation is the primary means of influenza treatment. A compound cocktail composed of arctiin, daidzein, glycyrrhizic acid, and liquiritin inhibited mouse pneumonia resulting from a PR8 viral infection and caused a weight gain after oral administration. Natural killer cell activating receptors, both Ly49D and Ly49H in the lungs, were increased in the treatment in mice. In H3N2 virus-infected natural killer-92MI cells, the cocktail treatment had different effects on phosphorylation sites of phospholipase Cγ1 (PLCγ1) and killed infected cells through necroptosis or late apoptosis, in which RIP3 was increased and both caspase-3 and phosphorylated-JNK in the cells were downregulated. Acid phosphatase activity in viral-infected natural killer-92MI cells was induced by the compound cocktail treatment, which could be related to the p62 decrease in natural killer-92MI cells. In addition, an autophagic flux induction was observed in alveolar basal epithelial cells (A549). Protein p65, but not phosphorylated-p65, was significantly decreased by the treatment. Our results indicate that the compound cocktail strengthened the phosphorylation of PLCγ1-related necroptosis and partial autophagy in natural killer cells, which could yield an inhibitory effect on viral pneumonia in influenza.

Anticancer effect of sodium metavanadate on murine breast cancer both in vitro and in vivo

Sodium metavanadate (NaVO₃) exhibits important physiological effects including insulin-like, chemoprevention and anticancer activity. However, the effects of NaVO₃ on breast cancer and underlying mechanisms are still unclear. In this study, our results revealed that NaVO₃ was able to inhibit proliferation of murine breast cancer cells 4T1 with IC₅₀ value of 8.19 μM and 1.92 μM at 24 h and 48 h, respectively. The mechanisms underlying the inhibition activity were that NaVO₃ could increase reactive oxygen species (ROS) level in a concentration-dependent way, arrest cells at G2/M phase, diminish the mitochondrial membrane potential (MMP), finally promote the progress of apoptosis. Furthermore, NaVO₃ also exhibited a dose-dependent anticancer activity in breast cancer-bearing mice that led to the shrinkage of tumor volume (about 50%), lower microvessel density, less propagating cells and more apoptotic cells in vivo, as compared to the saline group. Therefore, NaVO₃ may act as a potential chemotherapeutic agent in breast cancer treatment.

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.

Effects of melatonin to arecoline-induced reactive oxygen species production and DNA damage in oral squamous cell carcinoma

BACKGROUND/PURPOSE

Arecoline, the major alkaloid of areca nut, is known to induce reactive oxygen species (ROS) and DNA damage during oral cancer progression. This study aim to evaluate whether melatonin, an antioxidant, supported or repressed the arecoline-induced carcinogenesis phenotypes in oral squamous cell carcinoma (OSCC).

METHODS

The cytotoxicity of arecoline or melatonin treatment alone and their co-treatment in the OSCC cell line OEC-M1 were analyzed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The cell cycle, cell death, and total ROS production were analyzed using flow cytometer. The protein expression was determined using western blot analysis. The genotoxicity and mutation rate were determined using micronucleus assay and hypoxanthine phosphoribosyl transferase (HPRT) forward mutation assay, respectively, in CHO-K1 cells. The ataxia telangiectasia mutated (ATM) promoter activity and DNA repair ability were determined through reporter assay.

RESULTS

The result showed that both the arecoline and melatonin induced ROS production and antioxidant enzymes expression. Melatonin treatment enhanced arecoline-induced ROS production, cytotoxicity, G2/M phase arrest, and cell apoptosis in OSCC cells. On the other hand, melatonin treatment activated DNA repair activity to reverse arecoline-induced DNA damage and mutation.

CONCLUSION

These results indicated that melatonin is a potential chemopreventive agent for betel quid chewers to prevent OSCC initiation and progression.

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.

Possible Selective Cytotoxicity of Vanadium Complex on Breast Cancer Cells Involving Pathophysiological Pathways

Background:

Triple-Negative Breast Cancers (TNBC) are among the most aggressive and therapyresistant breast tumors. Development of new treatment strategies that target pathways involved in cancer cells resistance is an attractive candidate to overcome therapeutic resistance.

Objective:

To clarify the antitumor activity of [VO (bpy)2 Cl] Cl complex as a new therapeutic agent through studying the interplay between apoptosis, autophagy and notch signaling pathways.

Methods:

Proliferation of MDA-MB-231 cells and IC50 value of the vanadium complex were assessed by MTT assay. Flow cytometry was utilized to detect cell cycle distribution, apoptosis assay, LC3 levels and Acid Vascular Organelles (AVOs). Caspase 3 levels were detected by ELISA. Changes in Notch1 gene expression were assessed by real-time PCR. AVOs qualitative detection was assessed by a fluorescence microscope.

Results:

The growth of MDA-MB-231 cells was suppressed after treatment with [VO (bpy)2 Cl] Cl complex, in a dose-dependent manner. The affinity for apoptotic cell death induction was shown through the increase in the sub G0 peak, the percentage of early and late apoptotic phases, and the elevation in caspase 3 levels. The affinity for autophagic cell death induction was observed through the increase in the G0/G1 phase, G2/M arrest, the increase of AVOs red fluorescence and elevated LC3 levels. The affinity for notch pathway inhibition was shown through the suppression of Notch 1 gene expression.

Conclusion:

[VO (bpy)2 Cl] Cl complex could be a promising candidate as therapeutic agent targeting different therapeutic targets including apoptosis, autophagy and notch signaling pathways.

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.

Inhibitory effects of oxidovanadium complexes on the aggregation of human islet amyloid polypeptide and its fragments

Human islet amyloid polypeptide (hIAPP) is synthesized by pancreatic β-cells and co-secreted with insulin. Misfolding and amyloidosis of hIAPP induce β-cell dysfunction in type II diabetes mellitus. Numerous small organic molecules and metal complexes act as inhibitors against amyloid-related diseases, justifying the need to explore the inhibitory mechanism of these compounds. In this work, three oxidovanadium complexes, namely, (NH₄)[VO(O₂)₂(bipy)]·4H₂O (1) (bipy = 2,2' bipyridine), bis(ethyl-maltolato, O,O)oxido-vanadium(IV) (2), and (bipyH₂)H₂[O{VO(O₂)(bipy)}₂]·5H₂O (3), were synthesized and used to inhibit the aggregation of hIAPP and its fragments, namely, hIAPP19-37 and hIAPP20-29. Results revealed that shortening the peptide sequence decreased the aggregation capability of hIAPP fragments, and the oxidovanadium complexes inhibited the fibrillization of hIAPP better than its fragments. Interestingly, the binding of oxidovanadium complexes to hIAPP and its fragments presented a distinct thermodynamic behavior. Oxidovanadium complexes featured the disaggregation capability against hIAPP, better than against its fragments. These complexes also decreased the cytotoxicity caused by hIAPP and its fragments by reducing the production of oligomers. 3 may be a good hIAPP inhibitor based on its inhibition, disaggregation capability, and regulatory effect on peptide-induced cytotoxicity. Oxidovanadium complexes exhibit potential as metallodrugs against amyloidosis-related diseases.

Vanadium Compounds as Enzyme Inhibitors with a Focus on Anticancer Effects

Vanadium salts and coordination compounds have desirable cellular anticancer effects, and although they have been investigated in detail as a potential treatment for diabetes, less attention has been given to the anticancer effects. The inhibition of some signal transduction enzymes is known, and studies of the metabolism and activation pathways both in vitro and in vivo are important for future investigations and development of vanadium's role as a new potential drug. In addition, a new approach has demonstrated that the enhancement of oncolytic viruses using vanadium salts and coordination complexes for immunotherapy is very promising. Some differences exist between this approach and current antidiabetic and anticancer studies because vanadium(iv) complexes have been found to be most potent in the latter approach, but the few compounds investigated with oncolytic viruses show that vanadium(v) systems are more effective. We conclude that recent studies demonstrate effects on signal transduction enzymes and anticancer pathways, thus suggesting potential applications of vanadium as anticancer agents in the future both as standalone treatments as well as combination therapies.

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

Pancreatic cancer is characterized by one of the lowest five-year survival rates. In search for new treatments, some studies explored several metal complexes as potential anticancer drugs. Therefore, we investigated three newly synthesized oxidovanadium(IV) complexes with 2-methylnitrilotriacetate (bcma3-), N-(2-carbamoylethyl)iminodiacetate (ceida3-) and N-(phosphonomethyl)-iminodiacetate (pmida4-) ligands as potential anticancer compounds using pancreatic cancer cell lines. We measured: Cytotoxicity using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), neutral red (NR) and lactate dehydrogenase (LDH) assay; antiproliferative activity by bromodeoxyuridine BrdU assay; reactive oxygen species (ROS) generation and cell cycle analysis by flow cytometry; protein level by Western blot and cellular morphology by confocal laser scanning microscopy. The results showed that these oxidovanadium(IV) complexes were cytotoxic on pancreatic cancer cells (PANC-1 and MIA PaCa2), but not on non-tumor human immortalized pancreas duct epithelial cells (hTERT-HPNE) over the concentration range of 10⁻25 μM, following 48 h incubation. Furthermore, molecular mechanisms of cytotoxicity of [4-NH₂-2-Me(Q)H][VO(bcma)(H₂O)]2H₂O (T1) were dependent on antiproliterative activity, increased ROS generation, cell cycle arrest in G2/M phase with simultaneous triggering of the p53/p21 pathway, binucleation, and induction of autophagy. Our study indicates that oxidovanadium(IV) coordination complexes containing 2-methylnitrilotriacetate ligand are good candidates for preclinical development of novel anticancer drugs targeting pancreatic cancer.

Synthesis, characterization, DFT calculations and anticancer activity of a new oxidovanadium(iv) complex with a ligand derived from o-vanillin and thiophene

New vanadium complex was synthesized and fully characterized showing promising anticancer activity on triple negative breast cancer cells.

In vitrocytotoxicity and catalytic evaluation of dioxidovanadium(v) complexes in an azohydrazone ligand environment

Synthesis, characterization,in vitrocytotoxicity and catalytic potential of the dioxidovanadium(v) complexes of azohydrazones.

Vanadium compounds and cellular death mechanisms in the A549 cell line: The relevance of the compound valence

Non-small lung cell carcinoma has a high morbidity and mortality rates. The elective treatment for stage III and IV is cisplatinum that conveys serious toxic side effects. Vanadium compounds are metal molecules with proven antitumor activity that depends on its valence. Therefore, a better understanding of the mechanism of action of vanadium compounds is required. The aim of our study was to investigate the mechanisms of cell death induced by sodium metavanadate (NaVO₃ [V(+5)]) and vanadyl sulfate (VOSO₄ [(+4)]), both of which have reported apoptotic-inducing activity. We exposed the A549 cell line to various concentrations (0-100 μM) and to different exposure times to each compound and determined the cell viability and expression of caspases, reactive oxygen species (ROS) production, Bcl2, Bax, FasL and NO. Our results showed that neither compounds modified the basal expression of caspases or pro- and anti-apoptotic proteins. The only change observed was the 12- and 14-fold significant increase in ROS production induced by NaVO₃ and VOSO₄ , respectively, at 100 μm concentrations after 48 hours. Our results suggest that classical apoptotic mechanisms are not related to the cell death induced by the vanadium compounds evaluated here, and showed that the higher ROS production was induced by the [(+4)] valence compound. It is possible that the difference will be secondary to its higher oxidative status and thus higher ROS production, which leads to higher cell damage. In conclusion, our results suggest that the efficacy of the cell death mechanisms induced by vanadium compounds differ depending on the valence of the compound.

Vanadium: History, chemistry, interactions with α-amino acids and potential therapeutic applications

In the last 30 years, since the discovery that vanadium is a cofactor found in certain enzymes of tunicates and possibly in mammals, different vanadium-based drugs have been developed targeting to treat different pathologies. So far, the in vitro studies of the insulin mimetic, antitumor and antiparasitic activity of certain compounds of vanadium have resulted in a great boom of its inorganic and bioinorganic chemistry. Chemical speciation studies of vanadium with amino acids under controlled conditions or, even in blood plasma, are essential for the understanding of the biotransformation of e.g. vanadium antidiabetic complexes at the physiological level, providing clues of their mechanism of action. The present article carries out a bibliographical research emphaticizing the chemical speciation of the vanadium with different amino acids and reviewing also some other important aspects such as its chemistry and therapeutical applications of several vanadium complexes.

Vanadium complex: an appropriate candidate for killing hepatocellular carcinoma cancerous cells

Hepatocellular carcinoma (HCC) is a prevalent human malignancy which its drug resistance is increasing world-wide. This project was designed to assess the anti-cancer effects of 4-bromo-2-(((5-chloro-2-hydroxyphenyl) imino) methyl) phenol ([IV(L)] complex) on the HepG2 cell line and also L929 cells, as normal cells. HepG2 and L929 cells were cultured in RPMI culture medium and the survival rates of the cells were determined after 24 and 48 h using MTT assay to find IC50 concentration of vanadium m, [IV(L)] complex. The early apoptosis and necrosis/late apoptosis were determined by means of annexin V/PI apoptosis detection kit. The results revealed that vanadium m, [IV(L)] complex induce early apoptosis higher in HepG2 cell line than L929 cells. The rates of necrosis/late apoptosis were also induced in HepG2 cells more than L929 cells. Based on the results, vanadium m, [IV(L)] complex might be considered as a safe new drug for treatment of HCC with low side effects on control liver cells.

Sodium orthovanadate overcomes sorafenib resistance of hepatocellular carcinoma cells by inhibiting Na+/K+-ATPase activity and hypoxia-inducible pathways

The resistance to sorafenib highly affects its clinical benefits for treating hepatocellular carcinoma (HCC). Sodium orthovanadate (SOV) is a phosphate analog that displays anti-cancer activities against various types of malignancies including HCC. The present study has demonstrated that SOV is able to overcome sorafenib resistance and strengthens sorafenib in suppressing sorafenib-resistant HCC cells in vitro and in animal models. Similar to its action on parental HCC cells, SOV induced cell cycle arrest at G2/M phases by regulating cyclin B1 and cyclin-dependent kinase 1, and apoptosis by reducing mitochondrial membrane potential, in sorafenib-resistant HCC cells. More importantly, SOV inhibited ATPase activity, which was significantly elevated in sorafenib-resistant HCC cells. SOV also reduced the expression of HIF-1α and HIF-2α and their nuclear translocation, resulting in downregulation of their downstream factors including vascular endothelial growth factor, lactate dehydrogenase-A and glucose transporter 1. Its ability to inhibit ATPase activity and hypoxia-inducible pathways enabled SOV to efficiently suppress both normoxic and hypoxic cells, which compose cancer cell populations inside sorafenib-resistant HCC tumors. The present results indicate that SOV may be a potent candidate drug for overcoming the resistance to sorafenib in treating HCC.

Synthesis of New Oxido-Vanadium Complexes: Catalytic Properties and Cytotoxicity

Reaction of 2,3-dihydroxy benzaldehyde with 2-({2-amino phenyl}diazenyl)phenol afforded the ligand 3-(2-(2-hydroxyphenyl)diazenyl)-4-alkylphenyliminomethyl)benzene-1,2-diol. Reaction of H2L with VOSO4. 5H2O gave the oxido-vanadium(IV) complexes [(L)VO], which exhibited a quasi-reversible oxidative cyclic voltammetric response in a V(IV)/V(V) oxidative process. The complexes act as catalysts in the oxidation of organic thioethers and bromination of phenol. Their cytotoxic properties were examined for three cancer cell lines.

Vanadium Compounds as PTP Inhibitors

Phosphotyrosine signaling is regulated by the opposing actions of protein tyrosine kinases (PTKs) and protein tyrosine phosphatases (PTPs). Here we discuss the potential of vanadium derivatives as PTP enzyme inhibitors and metallotherapeutics. We describe how vanadate in the V oxidized state is thought to inhibit PTPs, thus acting as a pan-inhibitor of this enzyme superfamily. We discuss recent developments in the biological and biochemical actions of more complex vanadium derivatives, including decavanadate and in particular the growing number of oxidovanadium compounds with organic ligands. Pre-clinical studies involving these compounds are discussed in the anti-diabetic and anti-cancer contexts. Although in many cases PTP inhibition has been implicated, it is also clear that many such compounds have further biochemical effects in cells. There also remain concerns surrounding off-target toxicities and long-term use of vanadium compounds in vivo in humans, hindering their progress through clinical trials. Despite these current misgivings, interest in these chemicals continues and many believe they could still have therapeutic potential. If so, we argue that this field would benefit from greater focus on improving the delivery and tissue targeting of vanadium compounds in order to minimize off-target toxicities. This may then harness their full therapeutic potential.

Two novel Mg(II)-based and Zn(II)-based complexes: inhibiting growth of human liver cancer cells

Two new Mg(II)-based and Zn(II)-based coordination polymers, {[Mg3(BTB)(DMA)4](DMA)2}n (1, H3BTB=1,3,5-benzenetrisbenzoic acid, DMA=N,N-dimethylacetamide) and {(H2NMe2)2[Zn3(BTB)2(OH)(Im)](DMF)9(MeOH)7}n (2, Im=imidazole, DMF=N,N-dimethylformamide), have been successfully synthesized and structurally characterized under solvothermal conditions. 1 contains a linear [Mg3(COO)6] cluster that connected by the fully deprotonated BTB3- ligands to give a kgd-type 2D bilayer structure; 2 represents a microporous 3D pillar-layered system based on the binuclear Zn units and pillared Im ligands, which shows a (3,5)-connected hms topological net. In addition, in vitro anticancer activities of compounds 1 and 2 on 4 human liver cancer cells (HB611, HHCC, BEL-7405 and SMMC-7721) were determined.