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BioAssay: AID 328608

Inhibition of NADPH-reduced rat recombinant TrxR1 at 0.25 uM attenuated in presence of 1 mM Glutathione after 30 minis

Arsenic trioxide (ATO) is an effective cancer therapeutic drug for acute promyelocytic leukemia and has potential anticancer activity against a wide range of solid tumors. ATO exerts its effect mainly through elevated oxidative stress, but the exact molecular mechanism remains elusive. The thioredoxin (Trx) system comprising NADPH, thioredoxin reductase (TrxR), and Trx and the glutathione (GSH) more ..
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 Tested Compounds
 Tested Compounds
All(1)
 
 
Active(1)
 
 
 Tested Substances
 Tested Substances
All(1)
 
 
Active(1)
 
 
AID: 328608
Data Source: ChEMBL (476634)
Depositor Category: Literature, Extracted
BioAssay Version:
Deposit Date: 2010-05-25
Modify Date: 2014-05-14

Data Table ( Complete ):           Active    All
Target
Sequence: RecName: Full=Thioredoxin reductase 1, cytoplasmic; Short=TR; AltName: Full=NADPH-dependent thioredoxin reductase; AltName: Full=Thioredoxin reductase TR1
Description ..   
Protein Family: Pyridine nucleotide-disulphide oxidoreductase, dimerization domain
Comment ..   

Gene:TXNRD1     Related Protein 3D Structures     More BioActivity Data..
BioActive Compound: 1
Description:
Title: Targeting thioredoxin reductase is a basis for cancer therapy by arsenic trioxide.

Abstract: Arsenic trioxide (ATO) is an effective cancer therapeutic drug for acute promyelocytic leukemia and has potential anticancer activity against a wide range of solid tumors. ATO exerts its effect mainly through elevated oxidative stress, but the exact molecular mechanism remains elusive. The thioredoxin (Trx) system comprising NADPH, thioredoxin reductase (TrxR), and Trx and the glutathione (GSH) system composed of NADPH, glutathione reductase, and GSH supported by glutaredoxin are the two electron donor systems that control cellular proliferation, viability, and apoptosis. Recently, the selenocysteine-dependent TrxR enzyme has emerged as an important molecular target for anticancer drug development. Here, we have discovered that ATO irreversibly inhibits mammalian TrxR with an IC(50) of 0.25 microM. Both the N-terminal redox-active dithiol and the C-terminal selenothiol-active site of reduced TrxR may participate in the reaction with ATO. The inhibition of MCF-7 cell growth by ATO was correlated with irreversible inactivation of TrxR, which subsequently led to Trx oxidation. Furthermore, the inhibition of TrxR by ATO was attenuated by GSH, and GSH depletion by buthionine sulfoximine enhanced ATO-induced cell death. These results strongly suggest that the ATO anticancer activity is by means of a Trx system-mediated apoptosis. Blocking cancer cell DNA replication and repair and induction of oxidative stress by the inhibition of both Trx and GSH systems are suggested as cancer chemotherapeutic strategies.
(PMID: 17640917)
Categorized Comment
Assay Type: Binding

Assay Data Source: Scientific Literature

BAO: Assay Format: biochemical format

Target Type: Target is a single protein chain

Result Definitions
TIDNameDescriptionHistogramTypeUnit
OutcomeThe BioAssay activity outcomeOutcome
1Activity activity commentActivity activity commentString
2Activity standard flagActivity standard flagInteger
3Activity qualifierActivity qualifierString
4Activity published valueActivity published valueFloat
5Activity standard valueActivity standard valueFloat

Data Table (Concise)
Classification
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