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Inorganic Chemistry Jul 2023Auranofin, a gold(I)-based complex, is under clinical trials for application as an anticancer agent for the treatment of nonsmall-cell lung cancer and ovarian cancer. In...
Auranofin, a gold(I)-based complex, is under clinical trials for application as an anticancer agent for the treatment of nonsmall-cell lung cancer and ovarian cancer. In the past years, different derivatives have been developed, modifying gold linear ligands in the search for new gold complexes endowed with a better pharmacological profile. Recently, a panel of four gold(I) complexes, inspired by the clinically established compound auranofin, was reported by our research group. As described, all compounds possess an [Au{P(OMe)}] cationic moiety, in which the triethylphosphine of the parent compound auranofin was replaced with an oxygen-rich trimethylphosphite ligand. The gold(I) linear coordination geometry was complemented by Cl, Br, I, and the auranofin-like thioglucose tetraacetate ligand. As previously reported, despite their close similarity to auranofin, the panel compounds exhibited some peculiar and distinctive features, such as lower log values which can induce relevant differences in the overall pharmacokinetic profiles. To get better insight into the P-Au strength and stability, an extensive study was carried out for relevant biological models, including three different vasopressin peptide analogues and cysteine, using P NMR and LC-ESI-MS. A DFT computational study was also carried out for a better understanding of the theoretical fundamentals of the disclosed differences with regard to triethylphosphine parent compounds.
Topics: Auranofin; Ligands; Gold; Antineoplastic Agents; Magnetic Resonance Spectroscopy
PubMed: 37342994
DOI: 10.1021/acs.inorgchem.3c01280 -
Cancer Chemotherapy and Pharmacology Jul 2023Cisplatin resistance is the major obstacle in the clinical treatment of ovarian cancer patients. Molecular mechanisms of cisplatin resistance are multifaceted....
PURPOSE
Cisplatin resistance is the major obstacle in the clinical treatment of ovarian cancer patients. Molecular mechanisms of cisplatin resistance are multifaceted. Gold(I)-compounds, i.e. N-heterocyclic carbene-gold(I)-complexes (NHC-Au(I)) has been regarded as promising cytotoxic drug candidates. However, their potential to overcome cisplatin resistance has hardly been addressed yet. Here we investigated the activity of the gold(I) drug auranofin and the NHC-Au(I)-compound MC3 in W1CR and A2780cis cisplatin-resistant ovarian cancer cells.
METHODS
Cytotoxicity of auranofin and MC3 was detected by MTT assay, correlated with intracellular gold(I) content, analyzed by AAS, and with flow cytometric detection of the cell cycle. Insight into cellular redox balance was provided by fluorimetric ROS-formation assay and western blotting thioredoxin (Trx) and Nrf2. The role of ERK was elucidated by using the inhibitor SCH772984 and its impact on cytotoxicity upon co-treatment with cisplatin and Au(I)-compounds, respectively.
RESULTS
MC3 overcomes cisplatin resistance in A2780cis and W1CR, and auranofin in W1CR cells completely, which is neither reflected by intracellular gold levels nor cell cycle changes. Upregulated redox balance appears as a basis for resistance. W1CR cells possess higher Trx levels, whereas A2780cis cells display strong Nrf2 expression as anti-oxidative protection. Nevertheless, overcoming redox balance appears not primary mode of activity comparing cisplatin and gold(I)-compounds. pERK emerges as a critical component and thus a promising target for overcoming resistance, regulating apoptosis differently in response to either gold(I) or cisplatin in A2780 cells.
CONCLUSION
These data reflect the complexity of cisplatin resistance in cell models and emphasize NHC-Au(I)-complexes as prospective cytotoxic agents for further investigations in that respect.
Topics: Humans; Female; Cisplatin; Ovarian Neoplasms; Gold; Auranofin; Cell Line, Tumor; NF-E2-Related Factor 2; Prospective Studies; Drug Resistance, Neoplasm; Antineoplastic Agents; Apoptosis
PubMed: 37272932
DOI: 10.1007/s00280-023-04548-1 -
Biomedicine & Pharmacotherapy =... May 2024Thioredoxin reductase 1 (TrxR1) has emerged as a promising target for cancer therapy. In our previous research, we discovered several new TrxR1 inhibitors and found that...
Thioredoxin reductase 1 (TrxR1) has emerged as a promising target for cancer therapy. In our previous research, we discovered several new TrxR1 inhibitors and found that they all have excellent anti-tumor activity. At the same time, we found these TrxR1 inhibitors all lead to an increase in AKT phosphorylation in cancer cells, but the detailed role of AKT phosphorylation in TrxR1 inhibitor-mediated cell death remains unclear. In this study, we identified the combination of AKT and TrxR1 inhibitor displayed a strong synergistic effect in colon cancer cells. Furthermore, we demonstrated that the synergistic effect of auranofin (TrxR1 inhibitor) and MK-2206 (AKT inhibitor) was caused by ROS accumulation. Importantly, we found that ATM inhibitor KU-55933 can block the increase of AKT phosphorylation caused by auranofin, and exhibited a synergistic effect with auranofin. Taken together, our study demonstrated that the activation of ATM/AKT pathway is a compensatory mechanism to cope with ROS accumulation induced by TrxR1 inhibitor, and synergistic targeting of TrxR1 and ATM/AKT pathway is a promising strategy for treating colon cancer.
Topics: Humans; Colonic Neoplasms; Proto-Oncogene Proteins c-akt; Thioredoxin Reductase 1; Drug Synergism; Auranofin; Ataxia Telangiectasia Mutated Proteins; Reactive Oxygen Species; Signal Transduction; Heterocyclic Compounds, 3-Ring; Cell Line, Tumor; Phosphorylation; Morpholines; HCT116 Cells; Pyrones
PubMed: 38565059
DOI: 10.1016/j.biopha.2024.116507 -
Scientific Reports Sep 2023Clostridioides difficile infections (CDIs) are responsible for a significant number of antibiotic-associated diarrheal cases. The standard-of-care antibiotics for C....
Clostridioides difficile infections (CDIs) are responsible for a significant number of antibiotic-associated diarrheal cases. The standard-of-care antibiotics for C. difficile are limited to fidaxomicin and vancomycin, with the recently obsolete metronidazole recommended if both are unavailable. No new antimicrobials have been approved for CDI since fidaxomicin in 2011, despite varying rates of treatment failure among all standard-of-care drugs. Drug repurposing is a rational strategy to generate new antimicrobials out of existing therapeutics approved for other indications. Auranofin is a gold-containing anti-rheumatic drug with antimicrobial activity against C. difficile and other microbes. In a previous report, our group hypothesized that inhibition of selenoprotein biosynthesis was auranofin's primary mechanism of action against C. difficile. However, in this study, we discovered that C. difficile mutants lacking selenoproteins are still just as sensitive to auranofin as their respective wild-type strains. Moreover, we found that selenite supplementation dampens the activity of auranofin against C. difficile regardless of the presence of selenoproteins, suggesting that selenite's neutralization of auranofin is not because of compensation for a chemically induced selenium deficiency. Our results clarify the findings of our original study and may aid drug repurposing efforts in discovering the compound's true mechanism of action against C. difficile.
Topics: Auranofin; Clostridioides; Clostridioides difficile; Fidaxomicin; Selenious Acid; Selenoproteins
PubMed: 37679389
DOI: 10.1038/s41598-023-36796-9 -
Microbiology Spectrum Feb 2024Drug repurposing efforts led to the discovery of bactericidal activity in auranofin, a gold-containing drug used to treat rheumatoid arthritis. Auranofin kills...
Drug repurposing efforts led to the discovery of bactericidal activity in auranofin, a gold-containing drug used to treat rheumatoid arthritis. Auranofin kills Gram-positive bacteria by inhibiting thioredoxin reductase, an enzyme that scavenges reactive oxygen species (ROS). Despite the presence of thioredoxin reductase in Gram-negative bacteria, auranofin is not always active against them. It is not clear whether the lack of activity in several Gram-negative bacteria is due to the cell envelope barrier or the presence of other ROS protective enzymes such as glutathione reductase (GOR). We previously demonstrated that chemical analogs of auranofin (MS-40 and MS-40S), but not auranofin, are bactericidal against the Gram-negative complex. Here, we explore the targets of auranofin, MS-40, and MS-40S in and elucidate the mechanism of action of the auranofin analogs by a genome-wide, randomly barcoded transposon screen (BarSeq). Auranofin and its analogs inhibited the thioredoxin reductase and induced ROS but did not inhibit the bacterial GOR. Genome-wide, BarSeq analysis of cells exposed to MS-40 and MS-40S compared to the ROS inducers arsenic trioxide, diamide, hydrogen peroxide, and paraquat revealed common and unique mediators of drug susceptibility. Furthermore, deletions of and that encode enzymes in the glutathione biosynthetic pathway led to increased susceptibility to MS-40 and MS-40S. Overall, our data suggest that the auranofin analogs kill by inducing ROS through inhibition of thioredoxin reductase and that the glutathione system has a role in protecting against these ROS-inducing compounds.IMPORTANCEThe Burkholderia cepacia complex is a group of multidrug-resistant bacteria that can cause infections in the lungs of people with the autosomal recessive disease, cystic fibrosis. Specifically, the bacterium Burkholderia cenocepacia can cause severe infections, reducing lung function and leading to a devastating type of sepsis, cepacia syndrome. This bacterium currently does not have an accepted antibiotic treatment plan because of the wide range of antibiotic resistance. Here, we further the research on auranofin analogs as antimicrobials by finding the mechanism of action of these potent bactericidal compounds, using a powerful technique called BarSeq, to find the global response of the cell when exposed to an antimicrobial.
Topics: Humans; Auranofin; Reactive Oxygen Species; Thioredoxin-Disulfide Reductase; Anti-Bacterial Agents; Burkholderia cepacia complex; Burkholderia cenocepacia; Glutathione
PubMed: 38206016
DOI: 10.1128/spectrum.03201-23 -
Biometals : An International Journal on... Oct 2023Auranofin ([1-(thio-κS)-β-D-glucopyranose-2,3,4,6-tetraacetato](triethylphosphine)-gold) is a leading gold-based drug clinically used to treat arthritis. In the last...
Auranofin ([1-(thio-κS)-β-D-glucopyranose-2,3,4,6-tetraacetato](triethylphosphine)-gold) is a leading gold-based drug clinically used to treat arthritis. In the last years, it entered various drug reprofiling programs, and it has been found promising against various forms of tumor, including ovarian cancer. Evidence showed as its antiproliferative profile mainly depends on the inhibition of thioredoxin reductase (TrxR), being this mitochondrial system its main target. In this context, we report here the synthesis and biological evaluation of a novel complex designed as auranofin analogue obtained through the conjugation of a phenylindolylglyoxylamide ligand (which belongs to the so-called PIGA TSPO ligand family) with the auranofin-derived cationic fragment [Au(PEt)]. This complex is characterized by two parts. The phenylindolylglyoxylamide moiety, owing to its high affinity for TSPO (in the low nM range) should drive the compound to target mitochondria, whereas the [Au(PEt)] cation is the actual anticancer-active molecular fragment. Overall, we wanted to offer the proof-of-concept that by coupling PIGA ligands to anticancer gold active moieties, it is possible to preserve and even improve anticancer effects, opening the avenue to a reliable approach for targeted therapy.
Topics: Humans; Female; Auranofin; Pharmacophore; Ligands; Antineoplastic Agents; Gold; Thioredoxin-Disulfide Reductase; Ovarian Neoplasms; Cell Line, Tumor; Receptors, GABA
PubMed: 36869967
DOI: 10.1007/s10534-023-00496-8 -
Cancer Genomics & Proteomics 2024Chemoresistance in rhabdomyosarcoma (RMS) is associated with poor survival, necessitating the development of novel anticancer drugs. Auranofin (AUR), an anti-rheumatic...
BACKGROUND/AIM
Chemoresistance in rhabdomyosarcoma (RMS) is associated with poor survival, necessitating the development of novel anticancer drugs. Auranofin (AUR), an anti-rheumatic drug, is a thioredoxin reductase (TXNRD) inhibitor with anticancer properties. Although patient-derived xenograft (PDX) models are essential for studying cancer biology, reports on sarcomas using the PDX model are scarce because of their rarity. This study aimed to investigate the effectiveness of AUR treatment in RMS using a PDX model to evaluate its impact on local progression.
MATERIALS AND METHODS
A 20-year-old woman who was diagnosed with alveolar RMS was used to generate the PDX model. RMS PDX tumors were implanted in nude mice and divided into non-treated (vehicle) and treated (AUR) groups. Tumor volume and weight were evaluated, and immunohistochemical staining was performed to evaluate local progression of the sarcoma. The relationship between the TXNRD-1 expression and survival probability of patients with RMS was evaluated using publicly available expression cohorts.
RESULTS
AUR significantly suppressed RMS tumor progression over time. It also significantly suppressed the tumor size and weight at the time of excision. Histological evaluation showed that AUR induced oxidative stress in the PDX mouse models and inhibited the local progression of RMS by inducing apoptosis. High TXNRD-1 expression was found to be a negative prognostic factor for overall survival in patients with RMS.
CONCLUSION
AUR-induced inhibition of TXNRDs can significantly impede the local progression of RMS through the oxidative stress-apoptosis pathway as demonstrated in PDX models. Thus, targeting TXNRD inhibition may be a promising therapeutic strategy for the treatment of RMS.
Topics: Female; Humans; Animals; Mice; Young Adult; Adult; Thioredoxin-Disulfide Reductase; Mice, Nude; Rhabdomyosarcoma; Sarcoma; Auranofin; Disease Models, Animal; Xenograft Model Antitumor Assays; Cell Line, Tumor
PubMed: 38423598
DOI: 10.21873/cgp.20439