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BioAssay: AID 651768

qHTS for Inhibitors of WRN Helicase

Inhibition of DNA repair is proposed as a strategy for combating cancer. Synthetic lethality is an approach that exploits preexisting DNA repair deficiencies in certain tumors to develop inhibitors of DNA repair pathways that compensate for the tumor-associated DNA repair deficiency. Because helicases play critical roles in the DNA damage response and in DNA repair, particularly in actively more ..
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 Tested Compounds
 Tested Compounds
All(363999)
 
 
Active(1678)
 
 
Inactive(356003)
 
 
Inconclusive(6336)
 
 
 Tested Substances
 Tested Substances
All(364325)
 
 
Active(1678)
 
 
Inactive(356305)
 
 
Inconclusive(6342)
 
 
AID: 651768
Data Source: NCGC (WRN100)
BioAssay Type: Confirmatory, Concentration-Response Relationship Observed
Depositor Category: NIH Molecular Libraries Probe Production Network
BioAssay Version:
Deposit Date: 2012-11-08
Modify Date: 2012-11-16

Data Table ( Complete ):           View Active Data    View All Data
Target
BioActive Compounds: 1678
Related Experiments
AIDNameTypeComment
651767qHTS for Inhibitors of WRN Helicase: SummarySummarydepositor-specified cross reference: Summary AID
720497qHTS for Inhibitors of WRN Helicase: Confirmatory Assay for Cherry-picked Compounds.Confirmatorydepositor-specified cross reference
720499qHTS for Inhibitors of WRN Helicase: Thiazole Orange DNA Binding CounterscreenConfirmatorydepositor-specified cross reference
720503qHTS for Inhibitors of WRN Helicase: BLM Helicase Counterscreen for WRN InhibitorsConfirmatorydepositor-specified cross reference
Description:
Inhibition of DNA repair is proposed as a strategy for combating cancer. Synthetic lethality is an approach that exploits preexisting DNA repair deficiencies in certain tumors to develop inhibitors of DNA repair pathways that compensate for the tumor-associated DNA repair deficiency. Because helicases play critical roles in the DNA damage response and in DNA repair, particularly in actively dividing and replicating cells, characterization of synthetic lethal relationships of DNA helicases may be of value in developing improved anticancer treatment strategies; moreover, small molecules that specifically target a given DNA helicase may be useful for understanding its role in cellular nucleic acid metabolism. The goal of this project is to identify small molecule, non-covalent chemical inhibitors of the Werner syndrome (WS) helicase (WRN), which plays an important role in cell proliferation, the replication stress response, and DNA repair. Werner syndrome is a premature aging disorder that displays many clinical symptoms of aging at an accelerated rate. The WRN gene product that is defective in the chromosomal instability disorder has DNA helicase and exonuclease activities and interacts with a number of nuclear proteins to maintain genomic stability.

We will employ an optimized high-throughput screening assay that utilizes a fluorescence intensity modulation scheme with a fluorophore and quencher positioned near one another within a duplex deoxyoligonucleotide that contains a single forked structure. After a high-throughput screen of the ~350,000-member Molecular Libraries Small Molecule Repository (MLSMR) collection, followed by data analysis and hit selection, a panel of confirmatory, as well as secondary and ternary, assays will be employed to identify high-confidence WRN inhibitors. Structure-activity relationships will be investigated for the top candidate inhibitor series through medchem expansion. These are the results of the primary screening campaign against the MLSMR.

NIH Chemical Genomics Center [NCGC]
NIH Molecular Libraries Probe Centers Network [MLPCN]

MLPCN Grant: MH096530
Assay Submitter (PI): Robert Brosh, National Institute of Aging
Protocol
Three muL of reagents (buffer in columns 3 and 4 as negative controls; WRN at 20 nM final concentration in columns 1 and 2 as positive controls; columns 5-48 as test reactions) will be dispensed into a 1536-well Greiner black plate via solenoid-valve based nanoliter dispensers. Compounds (23 nL each in columns 5-48) and control (23 nL each in column 2 as dose-response) will be transferred via a Kalypsys pintool equipped with a 1536-pin array. Plates will be incubated for 15 min at room temperature, and then 1 muL of substrate (100 nM forked duplex oligonucleotide and 2 mM ATP final concentrations) will be added to start reaction, and plate will be transferred into a ViewLux high-throughput CCD imager where reaction progress is measured in kinetic mode using standard red-fluorescence optics (excitation filter 525 nm, emission filter 598 nm).
Comment
Compound Ranking:

1. Compounds are first classified as having full titration curves, partial modulation, partial curve (weaker actives), single point activity (at highest concentration only), or inactive. See data field "Curve Description". For this assay, apparent inhibitors are ranked higher than compounds that showed apparent activation.
2. For all inactive compounds, PUBCHEM_ACTIVITY_SCORE is 0. For all active compounds, a score range was given for each curve class type given above. Active compounds have PUBCHEM_ACTIVITY_SCORE between 40 and 100. Inconclusive compounds have PUBCHEM_ACTIVITY_SCORE between 1 and 39. Fit_LogAC50 was used for determining relative score and was scaled to each curve class' score range.
Categorized Comment - additional comments and annotations
From ChEMBL:
Assay Type: Functional
Assay Cell Type: NULL
Result Definitions
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TIDNameDescriptionHistogramTypeUnit
OutcomeThe BioAssay activity outcomeOutcome
ScoreThe BioAssay activity ranking scoreInteger
1PhenotypeIndicates type of activity observed: inhibitor, activator, fluorescent, cytotoxic, inactive, or inconclusive.String
2Potency*Concentration at which compound exhibits half-maximal efficacy, AC50. Extrapolated AC50s also include the highest efficacy observed and the concentration of compound at which it was observed.FloatμM
3EfficacyMaximal efficacy of compound, reported as a percentage of control. These values are estimated based on fits of the Hill equation to the dose-response curves.Float%
4Analysis CommentAnnotation/notes on a particular compound's data or its analysis.String
5Activity_ScoreActivity score.Integer
6Curve_DescriptionA description of dose-response curve quality. A complete curve has two observed asymptotes; a partial curve may not have attained its second asymptote at the highest concentration tested. High efficacy curves exhibit efficacy greater than 80% of control. Partial efficacies are statistically significant, but below 80% of control.String
7Fit_LogAC50The logarithm of the AC50 from a fit of the data to the Hill equation (calculated based on Molar Units).Float
8Fit_HillSlopeThe Hill slope from a fit of the data to the Hill equation.Float
9Fit_R2R^2 fit value of the curve. Closer to 1.0 equates to better Hill equation fit.Float
10Fit_InfiniteActivityThe asymptotic efficacy from a fit of the data to the Hill equation.Float%
11Fit_ZeroActivityEfficacy at zero concentration of compound from a fit of the data to the Hill equation.Float%
12Fit_CurveClassNumerical encoding of curve description for the fitted Hill equation.Float
13Excluded_PointsWhich dose-response titration points were excluded from analysis based on outlier analysis. Each number represents whether a titration point was (1) or was not (0) excluded, for the titration series going from smallest to highest compound concentrations.String
14Max_ResponseMaximum activity observed for compound (usually at highest concentration tested).Float%
15Activity at 0.0009677143 uM (0.000967714μM**)% Activity at given concentration.Float%
16Activity at 0.00194 uM (0.00193543μM**)% Activity at given concentration.Float%
17Activity at 0.00298 uM (0.00297648μM**)% Activity at given concentration.Float%
18Activity at 0.00581 uM (0.00580629μM**)% Activity at given concentration.Float%
19Activity at 0.00871 uM (0.00870949μM**)% Activity at given concentration.Float%
20Activity at 0.017 uM (0.017419μM**)% Activity at given concentration.Float%
21Activity at 0.026 uM (0.0261284μM**)% Activity at given concentration.Float%
22Activity at 0.052 uM (0.0522568μM**)% Activity at given concentration.Float%
23Activity at 0.080 uM (0.0798584μM**)% Activity at given concentration.Float%
24Activity at 0.157 uM (0.156771μM**)% Activity at given concentration.Float%
25Activity at 0.235 uM (0.235156μM**)% Activity at given concentration.Float%
26Activity at 0.469 uM (0.469047μM**)% Activity at given concentration.Float%
27Activity at 0.705 uM (0.705467μM**)% Activity at given concentration.Float%
28Activity at 1.280 uM (1.27968μM**)% Activity at given concentration.Float%
29Activity at 2.260 uM (2.25959μM**)% Activity at given concentration.Float%
30Activity at 4.233 uM (4.2328μM**)% Activity at given concentration.Float%
31Activity at 6.349 uM (6.34921μM**)% Activity at given concentration.Float%
32Activity at 11.58 uM (11.5829μM**)% Activity at given concentration.Float%
33Activity at 19.05 uM (19.0476μM**)% Activity at given concentration.Float%
34Activity at 38.10 uM (38.0952μM**)% Activity at given concentration.Float%
35Activity at 57.11 uM (57.1065μM**)% Activity at given concentration.Float%
36Activity at 114.0 uM (114μM**)% Activity at given concentration.Float%
37Activity at 114.3 uM (114.286μM**)% Activity at given concentration.Float%
38Compound QCNCGC designation for data stage: 'qHTS', 'qHTS Verification', 'Secondary Profiling'String

* Activity Concentration. ** Test Concentration.
Additional Information
Grant Number: MH096530

Data Table (Concise)
Data Table ( Complete ):     View Active Data    View All Data
Classification
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