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Alteration of thioredoxin reductase 1 levels in elucidating cancer etiology.

ABSTRACT: Thioredoxin reductase 1 (TR1) is a major antioxidant and redox regulator in mammalian cells and appears to function as a double-edged sword in that it has roles in preventing and promoting/sustaining cancer. TR1 is overexpressed in many cancer cells and targeting its removal often leads to a reversal in numerous malignant characteristics which has marked this selenoenzyme as a prime target for cancer therapy. Since alterations in TR1 activity may lead to a better understanding of the etiology of cancer and new avenues for providing better therapeutic procedures, we have described herein techniques for removing and reexpressing TR1 employing RNAi technology and for assessing the catalytic activity of this enzyme.

SUBMITTER: Yoo MH

PROVIDER: S-EPMC3088101 | biostudies-literature | 2010

REPOSITORIES: biostudies-literature

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Alteration of thioredoxin reductase 1 levels in elucidating cancer etiology.

Yoo Min-Hyuk MH Carlson Bradley A BA Tsuji Petra P Irons Robert R Gladyshev Vadim N VN Hatfield Dolph L DL

Methods in enzymology 20100620

Thioredoxin reductase 1 (TR1) is a major antioxidant and redox regulator in mammalian cells and appears to function as a double-edged sword in that it has roles in preventing and promoting/sustaining cancer. TR1 is overexpressed in many cancer cells and targeting its removal often leads to a reversal in numerous malignant characteristics which has marked this selenoenzyme as a prime target for cancer therapy. Since alterations in TR1 activity may lead to a better understanding of the etiology of ...[more]

PMID: 20609915

Similar Datasets

Role of thioredoxin reductase 1 and thioredoxin interacting protein in prognosis of breast cancer.

Project description:INTRODUCTION: The purpose of this work was to study the prognostic influence in breast cancer of thioredoxin reductase 1 (TXNRD1) and thioredoxin interacting protein (TXNIP), key players in oxidative stress control that are currently evaluated as possible therapeutic targets. METHODS: Analysis of the association of TXNRD1 and TXNIP RNA expression with the metastasis-free interval (MFI) was performed in 788 patients with node-negative breast cancer, consisting of three individual cohorts (Mainz, Rotterdam and Transbig). Correlation with metagenes and conventional clinical parameters (age, pT stage, grading, hormone and ERBB2 status) was explored. MCF-7 cells with a doxycycline-inducible expression of an oncogenic ERBB2 were used to investigate the influence of ERBB2 on TXNRD1 and TXNIP transcription. RESULTS: TXNRD1 was associated with worse MFI in the combined cohort (hazard ratio = 1.955; P < 0.001) as well as in all three individual cohorts. In contrast, TXNIP was associated with better prognosis (hazard ratio = 0.642; P < 0.001) and similar results were obtained in all three subcohorts. Interestingly, patients with ERBB2-status-positive tumors expressed higher levels of TXNRD1. Induction of ERBB2 in MCF-7 cells caused not only an immediate increase in TXNRD1 but also a strong decrease in TXNIP. A subsequent upregulation of TXNIP as cells undergo senescence was accompanied by a strong increase in levels of reactive oxygen species. CONCLUSIONS: TXNRD1 and TXNIP are associated with prognosis in breast cancer, and ERBB2 seems to be one of the factors shifting balances of both factors of the redox control system in a prognostic unfavorable manner.

| S-EPMC2917039 | biostudies-literature

Thioredoxin reductase.

Project description:The mammalian thioredoxin reductases (TrxRs) are a family of selenium-containing pyridine nucleotide-disulphide oxidoreductases with mechanistic and sequence identity, including a conserved -Cys-Val-Asn-Val-Gly-Cys- redox catalytic site, to glutathione reductases. TrxRs catalyse the NADPH-dependent reduction of the redox protein thioredoxin (Trx), as well as of other endogenous and exogenous compounds. The broad substrate specificity of mammalian TrxRs is due to a second redox-active site, a C-terminal -Cys-SeCys- (where SeCys is selenocysteine), that is not found in glutathione reductase or Escherichia coli TrxR. There are currently two confirmed forms of mammalian TrxRs, TrxR1 and TrxR2, and it is possible that other forms will be identified. The availability of Se is a key factor determining TrxR activity both in cell culture and in vivo, and the mechanism(s) for the incorporation of Se into TrxRs, as well as the regulation of TrxR activity, have only recently begun to be investigated. The importance of Trx to many aspects of cell function make it likely that TrxRs also play a role in protection against oxidant injury, cell growth and transformation, and the recycling of ascorbate from its oxidized form. Since TrxRs are able to reduce a number of substrates other than Trx, it is likely that additional biological effects will be discovered for TrxR. Furthermore, inhibiting TrxR with drugs may lead to new treatments for human diseases such as cancer, AIDS and autoimmune diseases.

| S-EPMC1220815 | biostudies-other

Thioredoxin reductase 1 deficiency enhances selenite toxicity in cancer cells via a thioredoxin-independent mechanism.

Project description:Selenium is an essential trace element in mammals, but is toxic at high levels. It is best known for its cancer prevention activity, but cancer cells are more sensitive to selenite toxicity than normal cells. Since selenite treatment leads to oxidative stress, and the Trx (thioredoxin) system is a major antioxidative system, we examined the interplay between TR1 (Trx reductase 1) and Trx1 deficiencies and selenite toxicity in DT cells, a malignant mouse cell line, and the corresponding parental NIH 3T3 cells. TR1-deficient cells were far more sensitive to selenite toxicity than Trx1-deficient or control cells. In contrast, this effect was not seen in cells treated with hydrogen peroxide, suggesting that the increased sensitivity of TR1 deficiency to selenite was not due to oxidative stress caused by this compound. Further analyses revealed that only TR1-deficient cells manifested strongly enhanced production and secretion of glutathione, which was associated with increased sensitivity of the cells to selenite. The results suggest a new role for TR1 in cancer that is independent of Trx reduction and compensated for by the glutathione system. The results also suggest that the enhanced selenite toxicity of cancer cells and simultaneous inhibition of TR1 can provide a new avenue for cancer therapy.

| S-EPMC3508724 | biostudies-literature

Thioredoxin reductase and its inhibitors.

Project description:Thioredoxin plays a crucial role in a wide number of physiological processes, which span from reduction of nucleotides to deoxyriboucleotides to the detoxification from xenobiotics, oxidants and radicals. The redox function of Thioredoxin is critically dependent on the enzyme Thioredoxin NADPH Reductase (TrxR). In view of its indirect involvement in the above mentioned physio/pathological processes, inhibition of TrxR is an important clinical goal. As a general rule, the affinities and mechanisms of binding of TrxR inhibitors to the target enzyme are known with scarce precision and conflicting results abound in the literature. A relevant analysis of published results as well as the experimental procedures is therefore needed, also in view of the critical interest of TrxR inhibitors. We review the inhibitors of TrxR and related flavoreductases and the classical treatment of reversible, competitive, non competitive and uncompetitive inhibition with respect to TrxR, and in some cases we are able to reconcile contradictory results generated by oversimplified data analysis.

| S-EPMC4275836 | biostudies-literature

Identification of targets of the protein disulfide reductase thioredoxin

Project description:Identification of targets of the protein disulfide reductase thioredoxin using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) and thiol specific differential labeling with isotope-coded affinity tags (ICAT). Reduction of specific target disulfides is quantified by measuring ratios of cysteine residues labeled with the heavy (13C) and light (12C) ICAT reagents in peptides derived from tryptic digests of Trx-treated and non-treated samples. Keywords: protein, LC-MS/MS, ICAT

2008-11-20 | GSE11650 | GEO

Hepatocyte Hyperproliferation upon Liver-Specific Co-disruption of Thioredoxin-1, Thioredoxin Reductase-1, and Glutathione Reductase.

Project description:Energetic nutrients are oxidized to sustain high intracellular NADPH/NADP+ ratios. NADPH-dependent reduction of thioredoxin-1 (Trx1) disulfide and glutathione disulfide by thioredoxin reductase-1 (TrxR1) and glutathione reductase (Gsr), respectively, fuels antioxidant systems and deoxyribonucleotide synthesis. Mouse livers lacking both TrxR1 and Gsr sustain these essential activities using an NADPH-independent methionine-consuming pathway; however, it remains unclear how this reducing power is distributed. Here, we show that liver-specific co-disruption of the genes encoding Trx1, TrxR1, and Gsr (triple-null) causes dramatic hepatocyte hyperproliferation. Thus, even in the absence of Trx1, methionine-fueled glutathione production supports hepatocyte S phase deoxyribonucleotide production. Also, Trx1 in the absence of TrxR1 provides a survival advantage to cells under hyperglycemic stress, suggesting that glutathione, likely via glutaredoxins, can reduce Trx1 disulfide in vivo. In triple-null livers like in many cancers, deoxyribonucleotide synthesis places a critical yet relatively low-volume demand on these reductase systems, thereby favoring high hepatocyte turnover over sustained hepatocyte integrity.

| S-EPMC5730093 | biostudies-literature

The mitochondrial thioredoxin reductase system (TrxR2) in vascular endothelium controls peroxynitrite levels and tissue integrity.

Project description:The mitochondrial thioredoxin/peroxiredoxin system encompasses NADPH, thioredoxin reductase 2 (TrxR2), thioredoxin 2, and peroxiredoxins 3 and 5 (Prx3 and Prx5) and is crucial to regulate cell redox homeostasis via the efficient catabolism of peroxides (TrxR2 and Trxrd2 refer to the mitochondrial thioredoxin reductase protein and gene, respectively). Here, we report that endothelial TrxR2 controls both the steady-state concentration of peroxynitrite, the product of the reaction of superoxide radical and nitric oxide, and the integrity of the vascular system. Mice with endothelial deletion of the Trxrd2 gene develop increased vascular stiffness and hypertrophy of the vascular wall. Furthermore, they suffer from renal abnormalities, including thickening of the Bowman's capsule, glomerulosclerosis, and functional alterations. Mechanistically, we show that loss of Trxrd2 results in enhanced peroxynitrite steady-state levels in both vascular endothelial cells and vessels by using a highly sensitive redox probe, fluorescein-boronate. High steady-state peroxynitrite levels were further found to coincide with elevated protein tyrosine nitration in renal tissue and a substantial change of the redox state of Prx3 toward the oxidized protein, even though glutaredoxin 2 (Grx2) expression increased in parallel. Additional studies using a mitochondria-specific fluorescence probe (MitoPY1) in vessels revealed that enhanced peroxynitrite levels are indeed generated in mitochondria. Treatment with Mn(III)tetrakis(1-methyl-4-pyridyl)porphyrin [Mn(III)TMPyP], a peroxynitrite-decomposition catalyst, blunted intravascular formation of peroxynitrite. Our data provide compelling evidence for a yet-unrecognized role of TrxR2 in balancing the nitric oxide/peroxynitrite ratio in endothelial cells in vivo and thus establish a link between enhanced mitochondrial peroxynitrite and disruption of vascular integrity.

| S-EPMC7896346 | biostudies-literature

Cloning of thioredoxin h reductase and characterization of the thioredoxin reductase-thioredoxin h system from wheat.

Project description:Thioredoxins h are ubiquitous proteins reduced by NADPH- thioredoxin reductase (NTR). They are able to reduce disulphides in target proteins. In monocots, thioredoxins h accumulate at high level in seeds and show a predominant localization in the nucleus of seed cells. These results suggest that the NTR-thioredoxin h system probably plays an important role in seed physiology. To date, the study of this system in monocots is limited by the lack of information about NTR. In the present study, we describe the cloning of a full-length cDNA encoding NTR from wheat ( Triticum aestivum ). The polypeptide deduced from this cDNA shows close similarity to NTRs from Arabidopsis, contains FAD- and NADPH-binding domains and a disulphide probably interacting with the disulphide at the active site of thioredoxin h. Wheat NTR was expressed in Escherichia coli as a His-tagged protein. The absorption spectrum of the purified recombinant protein is typical of flavoenzymes. Furthermore, it showed NADPH-dependent thioredoxin h reduction activity, thus confirming that the cDNA clone reported in the present study encodes wheat NTR. Using the His-tagged NTR and TRXhA (wheat thioredoxin h ), we successfully reconstituted the wheat NTR-thioredoxin h system in vitro, as shown by the insulin reduction assay. A polyclonal antibody was raised against wheat NTR after immunization of rabbits with the purified His-tagged protein. This antibody efficiently detected a single polypeptide of the corresponding molecular mass in seed extracts and it allowed the analysis of the pattern of accumulation of NTR in different wheat organs and developmental stages. NTR shows a wide distribution in wheat, but, surprisingly, its accumulation in seeds is low, in contrast with the level of thioredoxins h.

| S-EPMC1222897 | biostudies-other

Transcription profiling of Arabidopsis thioredoxin reductase knock-out mutant

Project description:Transcriptomic study of a thioredoxin reductase knock-out mutant. Biological question : Thioredoxins are small redox proteins implicated in crucial pathways of cell life. They are reduced by a conserved flavoprotein named NADPH-dependent thioredoxin reductase (NTR). In order to give an insight into the functions of the NTR/thioredoxin pathway in Arabidopsis, we have used a reverse genetic approch. Both NTR genes (NTRA and NTRB) have been inactivated in the double ntra ntrb mutant. T-DNA lines have been provided by the SALK library. Surprisingly, this mutant shows a limited phenotype suggested that some additional redox pathways are involved in compensating the inactivation of the NTR/thioredoxin pathway. In order to isolate compensatory genes that would be transcriptionally induced in the ntra ntrb mutant, we have performed this CATMA project. Seeds of the wild-type Col-0 ecotype and of the ntra ntrb homozygote double mutant were sowed in soil. Three replicates of lines were made (Col-0 1, 2 and 3 ntra ntrb 1, 2 and 3) : plants were put at different places of the greenhouse and grown at different times. Germination was synchronized by 4 days at 4C and plants were grown during 17 days, until they reached a 6 rosette leaves stage. Entire plants (30 plants per sample) were harvested, frozen in liquid nitrogen and stored at -80C until extraction.

2005-09-15 | E-MEXP-365 | biostudies-arrayexpress

ntr-Transcriptomic study of a thioredoxin reductase knock-out mutant.

Project description:rs04-02_ntr - ntr - Thioredoxins are small redox proteins implicated in crucial pathways of cell life. They are reduced by a conserved flavoprotein named NADPH-dependent thioredoxin reductase (NTR). In order to give an insight into the functions of the NTR/thioredoxin pathway in Arabidopsis, we have used a reverse genetic approch. Both NTR genes (NTRA and NTRB) have been inactivated in the double ntra ntrb mutant. T-DNA lines have been provided by the SALK library. Surprisingly, this mutant shows a limited phenotype suggested that some additional redox pathways are involved in compensating the inactivation of the NTR/thioredoxin pathway. In order to isolate compensatory genes that would be transcriptionally induced in the ntra ntrb mutant, we have performed this CATMA project. - Comparison of the transcript profile of the ntra ntrb knock-out mutant vs Col-0 wild-type ecotype. Seeds of the wild-type Col-0 ecotype and of the ntra ntrb homozygote double mutant were sowed in soil. Three replicates of lines were made (Col-0 1, 2 and 3 ntra ntrb 1, 2 and 3) : plants were put at different places of the greenhouse and grown at different times. Germination was synchronized by 4 days at 4degreeC and plants were grown during 17 days, until they reached a 6 rosette leaves stage. Entire plants (30 plants per sample) were harvested, frozen in liquid nitrogen and stored at 80degreeC until extraction. Keywords: gene knock out,wt vs mutant comparison

2007-06-20 | GSE7998 | GEO

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