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Nature Communications May 2024Checkpoint kinase 1 (CHK1) is critical for cell survival under replication stress (RS). CHK1 inhibitors (CHK1i's) in combination with chemotherapy have shown promising...
Checkpoint kinase 1 (CHK1) is critical for cell survival under replication stress (RS). CHK1 inhibitors (CHK1i's) in combination with chemotherapy have shown promising results in preclinical studies but have displayed minimal efficacy with substantial toxicity in clinical trials. To explore combinatorial strategies that can overcome these limitations, we perform an unbiased high-throughput screen in a non-small cell lung cancer (NSCLC) cell line and identify thioredoxin1 (Trx1), a major component of the mammalian antioxidant-system, as a determinant of CHK1i sensitivity. We establish a role for redox recycling of RRM1, the larger subunit of ribonucleotide reductase (RNR), and a depletion of the deoxynucleotide pool in this Trx1-mediated CHK1i sensitivity. Further, the TrxR inhibitor auranofin, an approved anti-rheumatoid arthritis drug, shows a synergistic interaction with CHK1i via interruption of the deoxynucleotide pool. Together, we show a pharmacological combination to treat NSCLC that relies on a redox regulatory link between the Trx system and mammalian RNR activity.
Topics: Checkpoint Kinase 1; Humans; Oxidation-Reduction; Thioredoxins; Cell Line, Tumor; Auranofin; Carcinoma, Non-Small-Cell Lung; Lung Neoplasms; Protein Kinase Inhibitors; Ribonucleoside Diphosphate Reductase; Ribonucleotide Reductases; Drug Synergism; Animals
PubMed: 38821952
DOI: 10.1038/s41467-024-48076-9 -
Molecular Cancer Therapeutics Jul 2013Despite significant treatment advances over the past decade, metastatic gastrointestinal stromal tumor (GIST) remains largely incurable. Rare diseases, such as GIST,...
Despite significant treatment advances over the past decade, metastatic gastrointestinal stromal tumor (GIST) remains largely incurable. Rare diseases, such as GIST, individually affect small groups of patients but collectively are estimated to affect 25 to 30 million people in the United States alone. Given the costs associated with the discovery, development, and registration of new drugs, orphan diseases such as GIST are often not pursued by mainstream pharmaceutical companies. As a result, "drug repurposing" or "repositioning," has emerged as an alternative to the traditional drug development process. In this study, we screened 796 U.S. Food and Drug Administration (FDA)-approved drugs and found that two of these compounds, auranofin (Ridaura) and fludarabine phosphate, effectively and selectively inhibited the proliferation of GISTs, including imatinib-resistant cells. One of the most notable drug hits, auranofin, an oral, gold-containing agent approved by the FDA in 1985 for the treatment of rheumatoid arthritis, was found to inhibit thioredoxin reductase activity and induce reactive oxygen species (ROS) production, leading to dramatic inhibition of GIST cell growth and viability. Importantly, the anticancer activity associated with auranofin was independent of imatinib-resistant status, but was closely related to the endogenous and inducible levels of ROS. Coupled with the fact that auranofin has an established safety profile in patients, these findings suggest for the first time that auranofin may have clinical benefit for patients with GIST, particularly in those suffering from imatinib-resistant and recurrent forms of this disease.
Topics: Apoptosis; Auranofin; Cell Culture Techniques; Cell Line, Tumor; Cell Proliferation; Drug Repositioning; Gastrointestinal Stromal Tumors; Humans; Vidarabine
PubMed: 23657945
DOI: 10.1158/1535-7163.MCT-12-0968 -
Virulence Dec 2021The slowing-down drug-discovery emphasized the importance of repurposing old drugs. This is particularly true when combating infections caused by therapy-refractory...
The slowing-down drug-discovery emphasized the importance of repurposing old drugs. This is particularly true when combating infections caused by therapy-refractory microorganisms, such as species and . Recent studies on responses to oxidative stress underscored the importance of targeting the underlying mechanisms. Auranofin, ebselen, PX-12, honokiol, and to a lesser extent, conoidin A are known to disturb redox-homeostasis systems in many organisms. Their antifungal activity was assessed against 27 isolates belonging to the major species: , and . Auranofin and honokiol were the most active against all species (mean MIC values of 2.875 and 6.143 μg/ml, respectively) and against isolates (mean MIC values of 4.0 and 3.563μg/ml respectively). Combinations of auranofin with voriconazole or honokiol revealed additive effects against 9/27 and 18/27 isolates, respectively. Synergistic interaction between auranofin and honokiol was only found against one isolate of . The effects of auranofin upon exposure to oxidative stress were also investigated. For all species except , the maximal growth in the presence of auranofin significantly decreased when adding a sublethal dose of menadione. The analysis of the expression of genes encoding oxidoreductase enzymes upon exposure of to honokiol unveiled the upregulation of many genes, especially those coding peroxiredoxins, thioredoxin reductases, and glutaredoxins. Altogether, these data suggest that auranofin and honokiol act via dampening the redox balance and support their repurposing as antifungals against species and .
Topics: Antifungal Agents; Auranofin; Biphenyl Compounds; Drug Repositioning; Lignans; Scedosporium
PubMed: 33825667
DOI: 10.1080/21505594.2021.1909266 -
Breast Cancer Research and Treatment Dec 2021Tumor cells are dependent on the glutathione and thioredoxin antioxidant pathways to survive oxidative stress. Since the essential amino acid methionine is converted to...
PURPOSE
Tumor cells are dependent on the glutathione and thioredoxin antioxidant pathways to survive oxidative stress. Since the essential amino acid methionine is converted to glutathione, we hypothesized that methionine restriction (MR) would deplete glutathione and render tumors dependent on the thioredoxin pathway and its rate-limiting enzyme thioredoxin reductase (TXNRD).
METHODS
Triple (ER/PR/HER2)-negative breast cancer (TNBC) cells were treated with control or MR media and the effects on reactive oxygen species (ROS) and antioxidant signaling were examined. To determine the role of TXNRD in MR-induced cell death, TXNRD1 was inhibited by RNAi or the pan-TXNRD inhibitor auranofin, an antirheumatic agent. Metastatic and PDX TNBC mouse models were utilized to evaluate in vivo antitumor activity.
RESULTS
MR rapidly and transiently increased ROS, depleted glutathione, and decreased the ratio of reduced glutathione/oxidized glutathione in TNBC cells. TXNRD1 mRNA and protein levels were induced by MR via a ROS-dependent mechanism mediated by the transcriptional regulators NRF2 and ATF4. MR dramatically sensitized TNBC cells to TXNRD1 silencing and the TXNRD inhibitor auranofin, as determined by crystal violet staining and caspase activity; these effects were suppressed by the antioxidant N-acetylcysteine. H-Ras-transformed MCF-10A cells, but not untransformed MCF-10A cells, were highly sensitive to the combination of auranofin and MR. Furthermore, dietary MR induced TXNRD1 expression in mammary tumors and enhanced the antitumor effects of auranofin in metastatic and PDX TNBC murine models.
CONCLUSION
MR exposes a vulnerability of TNBC cells to the TXNRD inhibitor auranofin by increasing expression of its molecular target and creating a dependency on the thioredoxin pathway.
Topics: Animals; Auranofin; Humans; Methionine; Mice; Oxidation-Reduction; Thioredoxin Reductase 1; Thioredoxin-Disulfide Reductase; Triple Negative Breast Neoplasms
PubMed: 34553295
DOI: 10.1007/s10549-021-06398-y -
Journal of Biological Inorganic... Oct 2020Native mass spectrometry is a potent technique to study and characterize biomacromolecules in their native state. Here, we have applied this method to explore the...
Native mass spectrometry is a potent technique to study and characterize biomacromolecules in their native state. Here, we have applied this method to explore the solution chemistry of human carbonic anhydrase I (hCA I) and its interactions with four different inhibitors, namely three sulfonamide inhibitors (AAZ, MZA, SLC-0111) and the dithiocarbamate derivative of morpholine (DTC). Through high-resolution ESI-Q-TOF measurements, the native state of hCA I and the binding of the above inhibitors were characterized in the molecular detail. Native mass spectrometry was also exploited to assess the direct competition in solution among the various inhibitors in relation to their affinity constants. Additional studies were conducted on the interaction of hCA I with the metallodrug auranofin, under various solution and instrumental conditions. Auranofin is a selective reagent for solvent-accessible free cysteine residues, and its reactivity was analyzed also in the presence of CA inhibitors. Overall, our investigation reveals that native mass spectrometry represents an excellent tool to characterize the solution behavior of carbonic anhydrase.
Topics: Auranofin; Carbonic Anhydrase I; Carbonic Anhydrase Inhibitors; Humans; Mass Spectrometry; Models, Molecular; Protein Binding; Protein Conformation
PubMed: 32926233
DOI: 10.1007/s00775-020-01818-8 -
International Journal of Molecular... Oct 2022Reactive oxygen species (ROS) homeostasis and mitochondrial metabolism are critical for the survival of cancer cells, including cancer stem cells (CSCs), which often...
Reactive oxygen species (ROS) homeostasis and mitochondrial metabolism are critical for the survival of cancer cells, including cancer stem cells (CSCs), which often cause drug resistance and cancer relapse. Auranofin is a mono-gold anti-rheumatic drug, and it has been repurposed as an anticancer agent working by the induction of both ROS increase and mitochondrial dysfunction. Hypothetically, increasing auranofin's positive charges via incorporating more gold atoms to enhance its mitochondria-targeting capacity could enhance its anti-cancer efficacy. Hence, in this work, both mono-gold and bi-gold compounds were designed and evaluated to test our hypothesis. The results showed that bi-gold compounds generally suppressed cancer cells proliferation better than their mono-gold counterparts. The most potent compound, BGC2a, substantially inhibited the antioxidant enzyme TrxR and increased the cellular ROS. BGC2a induced cell apoptosis, which could not be reversed by the antioxidant agent vitamin C, implying that the ROS induced by TrxR inhibition might not be the decisive cause of cell death. As expected, a significant proportion of BGC2a accumulated within mitochondria, likely contributing to mitochondrial dysfunction, which was further confirmed by measuring oxygen consumption rate, mitochondrial membrane potential, and ATP production. Moreover, BGC2a inhibited colony formation and reduced stem-like side population (SP) cells of A549. Finally, the compound effectively suppressed the tumor growth of both A549 and PANC-1 xenografts. Our study showed that mitochondrial disturbance may be gold-based compounds' major lethal factor in eradicating cancer cells, providing a new approach to developing potent gold-based anti-cancer drugs by increasing mitochondria-targeting capacity.
Topics: Humans; Reactive Oxygen Species; Auranofin; Antioxidants; Mitochondria; Apoptosis; Gold Compounds; Ascorbic Acid; Antirheumatic Agents; Adenosine Triphosphate; Cell Proliferation; Cell Line, Tumor; Neoplasms
PubMed: 36293028
DOI: 10.3390/ijms232012169 -
Journal of Medicinal Chemistry Sep 2019Auranofin, an FDA-approved arthritis drug, has recently been repurposed as a potential antimicrobial agent; it performed well against many Gram-positive bacteria,...
Auranofin, an FDA-approved arthritis drug, has recently been repurposed as a potential antimicrobial agent; it performed well against many Gram-positive bacteria, including multidrug resistant strains. It is, however, inactive toward Gram-negative bacteria, for which we are in dire need of new therapies. In this work, 40 auranofin analogues were synthesized by varying the structures of the thiol and phosphine ligands, and their activities were tested against ESKAPE pathogens. The study identified compounds that exhibited bacterial inhibition (MIC) and killing (MBC) activities up to 65 folds higher than that of auranofin, making them effective against Gram-negative pathogens. Both thiol and the phosphine structures influence the activities of the analogues. The trimethylphosphine and triethylphosphine ligands gave the highest activities against Gram-negative and Gram-positive bacteria, respectively. Our SAR study revealed that the thiol ligand is also very important, the structure of which can modulate the activities of the Au complexes for both Gram-negative and Gram-positive bacteria. Moreover, these analogues had mammalian cell toxicities either similar to or lower than that of auranofin.
Topics: A549 Cells; Anti-Bacterial Agents; Antirheumatic Agents; Auranofin; Cell Survival; Dose-Response Relationship, Drug; Gram-Negative Aerobic Bacteria; Gram-Positive Bacteria; Humans; Microbial Sensitivity Tests; Molecular Structure; Structure-Activity Relationship; Tumor Cells, Cultured
PubMed: 31386365
DOI: 10.1021/acs.jmedchem.9b00550 -
Antimicrobial Agents and Chemotherapy Jan 2017Under an NIH priority to identify new drugs to treat class B parasitic agents, we performed high-throughput screens, which identified the activity of auranofin (Ridaura)...
Under an NIH priority to identify new drugs to treat class B parasitic agents, we performed high-throughput screens, which identified the activity of auranofin (Ridaura) against Entamoeba histolytica and Giardia intestinalis, major causes of water- and foodborne outbreaks. Auranofin, an orally administered, gold (Au)-containing compound that was approved by the FDA in 1985 for treatment of rheumatoid arthritis, was effective in vitro and in vivo against E. histolytica and both metronidazole-sensitive and -resistant strains of Giardia We now report the results of an NIH-sponsored phase I trial to characterize the pharmacokinetics (PK) and safety of auranofin in healthy volunteers using modern techniques to measure gold levels. Subjects received orally 6 mg (p.o.) of auranofin daily, the recommended dose for rheumatoid arthritis, for 7 days and were followed for 126 days. Treatment-associated adverse events were reported by 47% of the subjects, but all were mild and resolved without treatment. The mean gold maximum concentration in plasma (C) at day 7 was 0.312 μg/ml and the half-life (t) 35 days, so steady-state blood levels would not be reached in short-term therapy. The highest concentration of gold, 13 μM (auranofin equivalent), or more than 25× the 50% inhibitory concentration (IC) for E. histolytica and 4× that for Giardia, was in feces at 7 days. Modeling of higher doses (9 and 21 mg/day) was performed for systemic parasitic infections, and plasma gold levels of 0.4 to 1.0 μg/ml were reached after 14 days of treatment at 21 mg/day. This phase I trial supports the idea of the safety of auranofin and provides important PK data to support its potential use as a broad-spectrum antiparasitic drug. (This study has been registered at ClinicalTrials.gov under identifier NCT02089048.).
Topics: Administration, Oral; Adult; Antiparasitic Agents; Antirheumatic Agents; Auranofin; Computer Simulation; Drug Administration Schedule; Drug Dosage Calculations; Drug Repositioning; Entamoeba histolytica; Female; Giardia lamblia; Gold; Half-Life; Healthy Volunteers; High-Throughput Screening Assays; Humans; Inhibitory Concentration 50; Male; Metronidazole; Models, Statistical; Tissue Distribution
PubMed: 27821451
DOI: 10.1128/AAC.01947-16 -
International Journal of Molecular... May 2021Chronic inflammation, which is promoted by the production and secretion of inflammatory mediators and cytokines in activated macrophages, is responsible for the...
Anti-Inflammatory Effect of Auranofin on Palmitic Acid and LPS-Induced Inflammatory Response by Modulating TLR4 and NOX4-Mediated NF-κB Signaling Pathway in RAW264.7 Macrophages.
Chronic inflammation, which is promoted by the production and secretion of inflammatory mediators and cytokines in activated macrophages, is responsible for the development of many diseases. Auranofin is a Food and Drug Administration-approved gold-based compound for the treatment of rheumatoid arthritis, and evidence suggests that auranofin could be a potential therapeutic agent for inflammation. In this study, to demonstrate the inhibitory effect of auranofin on chronic inflammation, a saturated fatty acid, palmitic acid (PA), and a low concentration of lipopolysaccharide (LPS) were used to activate RAW264.7 macrophages. The results show that PA amplified LPS signals to produce nitric oxide (NO) and various cytokines. However, auranofin significantly inhibited the levels of NO, monocyte chemoattractant protein-1, and pro-inflammatory cytokines, such as interleukin (IL)-1β, tumor necrosis factor-α, and IL-6, which had been increased by co-treatment with PA and LPS. Moreover, the expression of inducible NO synthase, IL-1β, and IL-6 mRNA and protein levels increased by PA and LPS were reduced by auranofin. In particular, the upregulation of NADPH oxidase (NOX) 4 and the translocation of the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) induced by PA and LPS were suppressed by auranofin. The binding between the toll-like receptor (TLR) 4 and auranofin was also predicted, and the release of NO and cytokines was reduced more by simultaneous treatment with auranofin and TLR4 inhibitor than by auranofin alone. In conclusion, all these findings suggested that auranofin had anti-inflammatory effects in PA and LPS-induced macrophages by interacting with TLR4 and downregulating the NOX4-mediated NF-κB signaling pathway.
Topics: Animals; Auranofin; Gene Expression Regulation; Humans; Inflammation; Lipopolysaccharides; Macrophages; Mice; NADPH Oxidase 4; NF-kappa B; Palmitic Acid; RAW 264.7 Cells; Toll-Like Receptor 4
PubMed: 34072916
DOI: 10.3390/ijms22115920 -
The Journal of Biological Chemistry Jan 2016The synthesis of selenocysteine, the 21st amino acid, occurs on its transfer RNA (tRNA), tRNA(Sec). tRNA(Sec) is initially aminoacylated with serine by seryl-tRNA...
The synthesis of selenocysteine, the 21st amino acid, occurs on its transfer RNA (tRNA), tRNA(Sec). tRNA(Sec) is initially aminoacylated with serine by seryl-tRNA synthetase and the resulting seryl moiety is converted to phosphoserine by O-phosphoseryl-tRNA kinase (PSTK) in eukaryotes. The selenium donor, selenophosphate is synthesized from selenide and ATP by selenophosphate synthetase. Selenocysteinyl-tRNA synthase (SepSecS) then uses the O-phosphoseryl-tRNA(Sec) and selenophosphate to form Sec-tRNA(Sec) in eukaryotes. Here, we report the characterization of selenocysteinyl-tRNA synthase from Leishmania donovani. Kinetoplastid SepSecS enzymes are phylogenetically closer to worm SepSecS. LdSepSecS was found to exist as a tetramer. Leishmania SepSecS enzyme was found to be active and able to complement the ΔselA deletion in Escherichia coli JS1 strain only in the presence of archaeal PSTK, indicating the conserved nature of the PSTK-SepSecS pathway. LdSepSecS was found to localize in the cytoplasm of the parasite. Gene deletion studies indicate that Leishmania SepSecS is dispensable for the parasite survival. The parasite was found to encode three selenoproteins, which were only expressed in the presence of SepSecS. Selenoproteins of L. donovani are not required for the growth of the promastigotes. Auranofin, a known inhibitor of selenoprotein synthesis showed the same sensitivity toward the wild-type and null mutants suggesting its effect is not through binding to selenoproteins. The three-dimensional structural comparison indicates that human and Leishmania homologs are structurally highly similar but their association modes leading to tetramerization seem different.
Topics: Amino Acid Sequence; Amino Acyl-tRNA Synthetases; Animals; Auranofin; Cell Line; Conserved Sequence; Cytoplasm; Enzyme Inhibitors; Gene Deletion; Leishmania donovani; Macrophages; Mice; Models, Molecular; Molecular Sequence Data; Organisms, Genetically Modified; Phylogeny; Protein Conformation; Protozoan Proteins; RNA, Transfer, Amino Acyl; Recombinant Proteins; Selenoproteins; Sequence Alignment; Virulence
PubMed: 26586914
DOI: 10.1074/jbc.M115.695007