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PloS One 2012Increased glutathione (GSH) and thioredoxin (Trx) metabolism are mechanisms that are widely implicated in resistance of cancer cells to chemotherapy. The current study...
Increased glutathione (GSH) and thioredoxin (Trx) metabolism are mechanisms that are widely implicated in resistance of cancer cells to chemotherapy. The current study determined if simultaneous inhibition of GSH and Trx metabolism enhanced cell killing of human head and neck squamous cell carcinoma (HNSCC) cells by a mechanism involving oxidative stress. Inhibition of GSH and Trx metabolism with buthionine sulfoximine (BSO) and auranofin (AUR), respectively, induced significant decreases in clonogenic survival compared to either drug alone in FaDu, Cal-27 and SCC-25 HNSCC cells in vitro and in vivo in Cal-27 xenografts. BSO+AUR significantly increased glutathione and thioredoxin oxidation and suppressed peroxiredoxin activity in vitro. Pre-treatment with N-acetylcysteine completely reversed BSO+AUR-induced cell killing in FaDu and Cal-27 cells, while catalase and selenium supplementation only inhibited BSO+AUR-induced cell killing in FaDu cells. BSO+AUR decreased caspase 3/7 activity in HNSCC cells and significantly reduced the viability of both Bax/Bak double knockout (DKO) and DKO-Bax reconstituted hematopoietic cells suggesting that necrosis was involved. BSO+AUR also significantly sensitized FaDu, Cal-27, SCC-25 and SQ20B cells to cell killing induced by the EGFR inhibitor Erlotinib in vitro. These results support the conclusion that simultaneous inhibition of GSH and Trx metabolism pathways induces oxidative stress and clonogenic killing in HNSCCs and this strategy may be useful in sensitizing HNSCCs to EGFR inhibitors.
Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Auranofin; Buthionine Sulfoximine; Carcinoma, Squamous Cell; Catalase; Cell Line, Tumor; Cell Survival; Drug Synergism; Erlotinib Hydrochloride; Female; Gene Knockdown Techniques; Glutathione; Glutathione Peroxidase; Glutathione Reductase; Head and Neck Neoplasms; Humans; Mice; Mice, Nude; Necrosis; Oxidation-Reduction; Oxidative Stress; Peroxiredoxins; Quinazolines; RNA, Small Interfering; Thioredoxin-Disulfide Reductase; Thioredoxins; Xenograft Model Antitumor Assays
PubMed: 23118946
DOI: 10.1371/journal.pone.0048175 -
Cancer Research Mar 2018Highly glycolytic cervical cancers largely resist treatment by cisplatin and coadministered pelvic irradiation as the present standard of care. In this study, we...
Highly glycolytic cervical cancers largely resist treatment by cisplatin and coadministered pelvic irradiation as the present standard of care. In this study, we investigated the effects of inhibiting glycolysis and thiol redox metabolism to evaluate them as alternate treatment strategies in these cancers. In a panel of multiple cervical cancer cell lines, we evaluated sensitivity to inhibition of glycolysis (2-deoxyglucose, 2-DG) with or without simultaneous inhibition of glutathione and thioredoxin metabolism (BSO/AUR). Intracellular levels of total and oxidized glutathione, thioredoxin reductase activity, and indirect measures of intracellular reactive oxygen species were compared before and after treatment. Highly radioresistant cells were the most sensitive to 2-DG, whereas intermediate radioresistant cells were sensitive to 2-DG plus BSO/AUR. In response to 2-DG/BSO/AUR treatment, we observed increased levels of intracellular oxidized glutathione, redox-sensitive dye oxidation, and decreased glucose utilization via multiple metabolic pathways including the tricarboxylic acid cycle. 2-DG/BSO/AUR treatment delayed the growth of tumors composed of intermediate radioresistant cells and effectively radiosensitized these tumors at clinically relevant radiation doses both and Overall, our results support inhibition of glycolysis and intracellular redox metabolism as an effective alternative drug strategy for the treatment of highly glycolytic and radioresistant cervical cancers. This study suggests a simple metabolic approach to strike at an apparent Achilles' heel in highly glycolytic, radioresistant forms of cervical cancers, possibly with broader applications in cancer therapy. .
Topics: Animals; Auranofin; Buthionine Sulfoximine; Cell Death; Cell Line, Tumor; Citric Acid Cycle; Deoxyglucose; Female; Glutathione; Glycolysis; Humans; Lactic Acid; Mice, Nude; Oxidation-Reduction; Radiation Tolerance; Reactive Oxygen Species; Thioredoxins; Uterine Cervical Neoplasms; Xenograft Model Antitumor Assays
PubMed: 29339540
DOI: 10.1158/0008-5472.CAN-17-2367 -
PloS One 2020Ataxia-Telangiectasia (A-T), a pleiotropic chromosomal breakage syndrome, is caused by the loss of the kinase Ataxia-telangiectasia mutated (ATM). ATM is not only...
Ataxia-Telangiectasia (A-T), a pleiotropic chromosomal breakage syndrome, is caused by the loss of the kinase Ataxia-telangiectasia mutated (ATM). ATM is not only involved in the response to DNA damage, but also in sensing and counteracting oxidative stress. Since a disturbed redox balance has been implicated in the pathophysiology of A-T lung disease, we aimed to further explore the interplay between ATM and oxidative stress in lung cells. Using a kinetic trapping approach, we could demonstrate an interaction between the trapping mutant TRX1-CS and ATM upon oxidative stress. We could further show that combined inhibition of thioredoxin reductase (TrxR) and ATM kinase activity, using Auranofin and KU55933 respectively, induced an increase in cellular reactive oxygen species (ROS) levels and protein oxidation in lung cells. Furthermore, ATM inhibition sensitized lung cells to Auranofin-induced cell death that could be rescued by ROS scavengers. As a consequence, targeted reduction of ATM by TRX1 could serve as a regulator of oxidative ATM activation and contribute to the maintenance of the cellular redox homeostasis. These results highlight the importance of the redox-active function of ATM in preventing ROS accumulation and cell death in lung cells.
Topics: A549 Cells; Animals; Ataxia Telangiectasia Mutated Proteins; Auranofin; Cell Death; HEK293 Cells; Humans; Mice; Morpholines; Oxidative Stress; Protein Kinase Inhibitors; Pyrones; Thioredoxin-Disulfide Reductase; Thioredoxins
PubMed: 33338048
DOI: 10.1371/journal.pone.0244060 -
Redox Biology Aug 2016Metastasis is the most life threatening aspect of breast cancer. It is a multi-step process involving invasion and migration of primary tumor cells with a subsequent...
Metastasis is the most life threatening aspect of breast cancer. It is a multi-step process involving invasion and migration of primary tumor cells with a subsequent colonization of these cells at a secondary location. The aim of the present study was to investigate the role of thioredoxin (Trx1) in the invasion and migration of breast cancer cells and to assess the strength of the association between high levels of Trx1 and thioredoxin reductase (TrxR1) expression with breast cancer patient survival. Our results indicate that the expression of both Trx1 and TrxR1 are statistically significantly increased in breast cancer patient cells compared with paired normal breast tissue from the same patient. Over-expression of Trx1 in MDA-MB-231 breast cancer cell lines enhanced cell invasion in in vitro assays while expression of a redox inactive mutant form of Trx1 (designated 1SS) or the antisense mRNA inhibited cell invasion. Addition of exogenous Trx1 also enhanced cell invasion, while addition of a specific monoclonal antibody that inhibits Trx1 redox function decreased cell invasion. Over-expression of intracellular Trx1 did not increase cell migration but expression of intracellular 1SS inhibited migration. Addition of exogenous Trx1 enhanced cell migration while 1SS had no effect. Treatment with auranofin inhibited TrxR activity, cell migration and clonogenic activity of MDA-MB-231 cells, while increasing reactive oxygen species (ROS) levels. Analysis of 25 independent cohorts with 5910 patients showed that Trx1 and TrxR1 were both associated with a poor patient prognosis in terms of overall survival, distant metastasis free survival and disease free survival. Therefore, targeting the Trx system with auranofin or other specific inhibitors may provide improved breast cancer patient outcomes through inhibition of cancer invasion and migration.
Topics: Auranofin; Breast Neoplasms; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cell Survival; Extracellular Space; Female; Gene Expression; Gene Expression Profiling; Humans; Oxidation-Reduction; Prognosis; Reactive Oxygen Species; Thioredoxin Reductase 1; Thioredoxins; Transcriptome
PubMed: 26760912
DOI: 10.1016/j.redox.2015.12.004 -
The Journal of Clinical Investigation Jun 1996The orphan nuclear receptor, peroxisome proliferator-activated receptor (PPAR) gamma, is implicated in mediating expression of fat-specific genes and in activating the...
The orphan nuclear receptor, peroxisome proliferator-activated receptor (PPAR) gamma, is implicated in mediating expression of fat-specific genes and in activating the program of adipocyte differentiation. The potential for regulation of PPAR gamma gene expression in vivo is unknown. We cloned a partial mouse PPAR gamma cDNA and developed an RNase protection assay that permits simultaneous quantitation of mRNAs for both gamma l and gamma 2 isoforms encoded by the PPAR gamma gene. Probes for detection of adipocyte P2, the obese gene product, leptin, and 18S mRNAs were also employed. Both gamma l and gamma 2 mRNAs were abundantly expressed in adipose tissue. PPAR gamma 1 expression was also detected at lower levels in liver, spleen, and heart; whereas, gamma l and gamma 2 mRNA were expressed at low levels in skeletal muscle. Adipose tissue levels of gamma l and gamma 2 were not altered in two murine models of obesity (gold thioglucose and ob/ob), but were modestly increased in mice with toxigene-induced brown fat ablation uncoupling protein diphtheria toxin A mice. Fasting (12-48 h) was associated with an 80% fall in PPAR gamma 2 and a 50% fall in PPAR gamma mRNA levels in adipose tissue. Western blot analysis demonstrated a marked effect of fasting to reduce PPAR gamma protein levels in adipose tissue. Similar effects of fasting on PPAR gamma mRNAs were noted in all three models of obesity. Insulin-deficient (streptozotocin) diabetes suppressed adipose tissue gamma l and gamma 2 expression by 75% in normal mice with partial restoration during insulin treatment. Levels of adipose tissue PPAR gamma 2 mRNA were increased by 50% in normal mice exposed to a high fat diet. In obese uncoupling protein diphtheria toxin A mice, high fat feeding resulted in de novo induction of PPAR gamma 2 expression in liver. We conclude (a) PPAR gamma 2 mRNA expression is most abundant in adipocytes in normal mice, but lower level expression is seen in skeletal muscle; (b) expression of adipose tissue gamma1 or gamma2 mRNAs is increased in only one of the three models of obesity; (c) PPAR gamma 1 and gamma 2 expression is downregulated by fasting and insulin-deficient diabetes; and (d) exposure of mice to a high fat diet increases adipose tissue expression of PPAR gamma (in normal mice) and induces PPAR gamma 2 mRNA expression in liver (in obese mice). These findings demonstrate in vivo modulation of PPAR gamma mRNA levels over a fourfold range and provide an additional level of regulation for the control of adipocyte development and function.
Topics: Adipocytes; Adipose Tissue; Adipose Tissue, Brown; Animals; Aurothioglucose; Base Sequence; DNA Primers; Diabetes Mellitus, Experimental; Dietary Fats; Diphtheria Toxin; Female; Gene Expression Regulation; Leptin; Liver; Male; Mice; Mice, Inbred C57BL; Mice, Obese; Molecular Sequence Data; Muscle, Skeletal; Myocardium; Obesity; Organ Specificity; Polymerase Chain Reaction; Protein Biosynthesis; Proteins; RNA, Messenger; RNA, Ribosomal, 16S; Receptors, Cytoplasmic and Nuclear; Reference Values; Spleen; Transcription Factors; Transcription, Genetic
PubMed: 8647948
DOI: 10.1172/JCI118703 -
Annals of the Rheumatic Diseases Feb 1985The question 'Does the use of second-line therapy confer long-term benefit on outcome measures in rheumatoid arthritis?' remains unanswered. The major obstacle which... (Clinical Trial)
Clinical Trial Review
The question 'Does the use of second-line therapy confer long-term benefit on outcome measures in rheumatoid arthritis?' remains unanswered. The major obstacle which prevents collection of the necessary data is the lack of a suitable control group. In this report experience with three 'second-line placebo groups' is described, and previous studies in the literature which incorporated a placebo group are reviewed. In the absence of concurrent corticosteroid therapy very few patients remain on placebo second-line medication after one year. Those that do, appear to have milder disease and are not representative of the group as a whole. Data on outcome measures need to be collected over two to five years, but the answer to the question which is posed does not depend upon larger and larger placebo groups which constitute increasing bias. To define the extent of benefit offered by the more powerful therapeutic agents a novel approach in regard to drug assessment will be required.
Topics: Anti-Inflammatory Agents; Arthritis, Rheumatoid; Auranofin; Aurothioglucose; Azathioprine; Clinical Trials as Topic; Cyclophosphamide; Gold Sodium Thiomalate; Humans; Ketotifen; Levamisole; Penicillamine; Placebos; Prognosis; Sulfasalazine
PubMed: 2858180
DOI: 10.1136/ard.44.2.134 -
Gut Jan 1986Gastrointestinal function was assessed in six patients with rheumatoid arthritis who had developed diarrhoea on treatment with Auranofin. With the administration of...
Gastrointestinal function was assessed in six patients with rheumatoid arthritis who had developed diarrhoea on treatment with Auranofin. With the administration of Auranofin whole gut transit time decreased markedly (to 50% or less of control values) in five of six patients. The speed of passage of intestinal contents through the colon was certainly increased but attempts to assess transit through the upper gastrointestinal tract failed because the breath hydrogen method gave inconclusive results. There was no evidence of colitis and in all cases biopsy of the rectal mucosa appeared normal by light microscopy. In the five patients with rapid intestinal transit faecal weight increased more than two-fold (range +44 to +335%) although in only three cases were the changes sufficient to cause an increased frequency of bowel action. Overall the concentration of sodium in faecal water increased three-fold (mean values rose from 10.6 to 38.3 mmol/l). There were no significant changes in the concentrations of either potassium or chloride but bicarbonate was reduced. Faecal pH fell from a mean value of 7.5 (range 6.8-7.9) to a mean value of 6.4 (range 6.0-7.4). In the three patients who developed overt diarrhoea and in two others taking Auranofin the intestinal uptake of 51Cr-EDTA was increased on average three-fold and there was a similar change in the ratio of the absorption of lactulose/mannitol. The mean clearance of alpha-1-antitrypsin from the circulation into the gastrointestinal tract was doubled. These data indicate an increase in intestinal permeability. In contrast the absorption of vitamin B12 was unaffected and there was no significant change in the excretion of faecal fat although one patient developed mild steatorrhoea. Thus in a selected group of subjects with rheumatoid arthritis the administration of Auranofin caused diarrhoea in association with a reversible defect in intestinal permeability but without significant change in the absorption of nutrients.
Topics: Adult; Aged; Anti-Inflammatory Agents; Arthritis, Rheumatoid; Auranofin; Aurothioglucose; Diarrhea; Feces; Female; Gold; Humans; Intestinal Absorption; Intestinal Mucosa; Intestines; Middle Aged; Permeability
PubMed: 3081411
DOI: 10.1136/gut.27.1.59 -
BMC Cancer May 2018The orally available gold complex auranofin (AF) has been used in humans, primarily as an antirheumatic/immunomodulatory agent. It has been safely administered to...
BACKGROUND
The orally available gold complex auranofin (AF) has been used in humans, primarily as an antirheumatic/immunomodulatory agent. It has been safely administered to healthy dogs to establish pharmacokinetic parameters for oral administration, and has also been used as a treatment in some dogs with immune-mediated conditions. Multiple in vitro studies have recently suggested that AF may possess antineoplastic properties. Spontaneous canine lymphoma may be a very useful translational model for the study of human lymphoma, prompting the evaluation of AF in canine lymphoma cells.
METHODS
We investigated the antineoplastic activity of AF in 4 canine lymphoid tumor derived cell lines through measurements of proliferation, apoptosis, thioredoxin reductase (TrxR) activity and generation of reactive oxygen species (ROS), and detected the effects of AF when combined with conventional cytotoxic drugs using the Chou and Talalay method. We also evaluated the antiproliferative effects of AF in primary canine lymphoma cells using a bioreductive fluorometric assay.
RESULTS
At concentrations that appear clinically achievable in humans, AF demonstrated potent antiproliferative and proapoptotic effects in canine lymphoid tumor cell lines. TrxR inhibition and increased ROS production was observed following AF treatment. Moreover, a synergistic antiproliferative effect was observed when AF was combined with lomustine or doxorubicin.
CONCLUSIONS
Auranofin appears to inhibit the growth and initiate apoptosis in canine lymphoma cells in vitro at clinically achievable concentrations. Therefore, this agent has the potential to have near-term benefit for the treatment of canine lymphoma, as well as a translational model for human lymphoma. Decreased TrxR activity and increasing ROS production may be useful biomarkers of drug exposure.
Topics: Animals; Antineoplastic Agents; Apoptosis; Auranofin; Cell Line, Tumor; Cell Proliferation; Dogs; Drug Screening Assays, Antitumor; Lymphoma; Reactive Oxygen Species; Thioredoxin-Disulfide Reductase
PubMed: 29724201
DOI: 10.1186/s12885-018-4450-2 -
ACS Infectious Diseases Oct 2019() infection poses a worldwide public health crisis, as chronic infection is rampant and can lead to gastric ulcers, gastritis, and gastric cancer. Unfortunately,...
() infection poses a worldwide public health crisis, as chronic infection is rampant and can lead to gastric ulcers, gastritis, and gastric cancer. Unfortunately, frontline therapies cause harmful side effects and are often ineffective due to antibiotic resistance. The FDA-approved drug auranofin is a gold complex with a Au(I) core coordinated with triethylphosphine and peracetylated thioglucose as the ligands. Auranofin is used for the treatment of rheumatoid arthritis and also displays potent activity against . One of auranofin's modes of action involves cell death by disrupting cellular thiol-redox balance maintained by thioredoxin reductase (TrxR), but this disruption leads to unwanted side effects due to mammalian cell toxicity. Here, we developed and tested sugar-modified analogs of auranofin as potential antibiotics against , with the rationale that modulating the sugar moiety would bias uptake by targeting bacterial cells and mitigating mammalian cell toxicity. Sugar-modified auranofin analogs displayed micromolar minimum inhibitory concentrations against , maintained nanomolar inhibitory activity against the target enzyme TrxR, and caused reduced toxicity to mammalian cells. Taken together, our results suggest that structurally modifying the sugar component of auranofin has the potential to yield superior antibiotics for the treatment of infection. Broadly, glyco-tailoring is an attractive approach for repurposing approved drugs.
Topics: Anti-Bacterial Agents; Auranofin; Cell Death; Drug Repositioning; Enzyme Inhibitors; Gold; Helicobacter Infections; Helicobacter pylori; Microbial Sensitivity Tests; Oxidative Stress; Sugars; Sulfhydryl Compounds; Thioredoxin-Disulfide Reductase
PubMed: 31487153
DOI: 10.1021/acsinfecdis.9b00251 -
Free Radical Biology & Medicine Oct 2014The most common form of newborn chronic lung disease, bronchopulmonary dysplasia (BPD), is thought to be caused by oxidative disruption of lung morphogenesis, which...
The most common form of newborn chronic lung disease, bronchopulmonary dysplasia (BPD), is thought to be caused by oxidative disruption of lung morphogenesis, which results in decreased pulmonary vasculature and alveolar simplification. Although cellular redox status is known to regulate cellular proliferation and differentiation, redox-sensitive pathways associated with these processes in developing pulmonary epithelium are unknown. Redox-sensitive pathways are commonly regulated by cysteine thiol modifications. Therefore two thiol oxidoreductase systems, thioredoxin and glutathione, were chosen to elucidate the roles of these pathways on cell death. Studies herein indicate that thiol oxidation contributes to cell death through impaired activity of glutathione-dependent and thioredoxin (Trx) systems and altered signaling through redox-sensitive pathways. Free thiol content decreased by 71% with hyperoxic (95% oxygen) exposure. Increased cell death was observed during oxygen exposure when either the Trx or the glutathione-dependent system was pharmacologically inhibited with aurothioglucose (ATG) or buthionine sulfoximine, respectively. However, inhibition of the Trx system yielded the smallest decrease in free thiol content (1.44% with ATG treatment vs 21.33% with BSO treatment). Although Trx1 protein levels were unchanged, Trx1 function was impaired during hyperoxic treatment as indicated by progressive cysteine oxidation. Overexpression of Trx1 in H1299 cells utilizing an inducible construct increased cell survival during hyperoxia, whereas siRNA knockdown of Trx1 during oxygen treatment reduced cell viability. Overall, this indicated that a comparatively small pool of proteins relies on Trx redox functions to mediate cell survival in hyperoxia, and the protective functions of Trx1 are progressively lost by its oxidative inhibition. To further elucidate the role of Trx1, potential Trx1 redox protein-protein interactions mediating cytoprotection and cell survival pathways were determined by utilizing a substrate trap (mass action trapping) proteomics approach. With this method, known Trx1 targets were detected, including peroxiredoxin-1as well as novel targets, including two HSP90 isoforms (HSP90AA1 and HSP90AB1). Reactive cysteines within the structure of HSP90 are known to modulate its ATPase-dependent chaperone activity through disulfide formation and S-nitrosylation. Whereas HSP90 expression is unchanged at the protein level during hyperoxic exposure, siRNA knockdown significantly increased hyperoxic cell death by 2.5-fold, indicating cellular dependence on HSP90 chaperone functions in response to hyperoxic exposure. These data support the hypothesis that hyperoxic impairment of Trx1 has a negative impact on HSP90-oxidative responses critical to cell survival, with potential implications for pathways implicated in lung development and the pathogenesis of BPD.
Topics: Bronchopulmonary Dysplasia; Buthionine Sulfoximine; Cell Line, Tumor; Cell Survival; Glutathione; HSP90 Heat-Shock Proteins; Humans; Hyperoxia; Lung; Oxidation-Reduction; Oxygen; Peroxiredoxins; RNA Interference; RNA, Small Interfering; Signal Transduction; Thioredoxin-Disulfide Reductase; Thioredoxins
PubMed: 25106706
DOI: 10.1016/j.freeradbiomed.2014.07.023