|Luminescence-based cell-based high throughput dose response assay for inhibitors of the Steroid Receptor Coactivator 3 (SRC3; NCOA3) - BioAssay Summary
Name: Luminescence-based cell-based high throughput dose response assay for inhibitors of the Steroid Receptor Coactivator 3 (SRC3; NCOA3). ..more
BioActive Compounds: 119
Depositor Specified Assays
Source (MLPCN Center Name): The Scripps Research Institute Molecular Screening Center (SRIMSC)
Affiliation: The Scripps Research Institute, TSRI
Assay Provider: Bert O'Malley, Baylor College of Medicine
Network: Molecular Library Probe Production Centers Network (MLPCN)
Grant Proposal Number: 5U19DK062434-09
Grant Proposal PI: Bert O'Malley, Baylor College of Medicine
External Assay ID: SRC3_INH_LUMI_1536_3XIC50 DRUN
Name: Luminescence-based cell-based high throughput dose response assay for inhibitors of the Steroid Receptor Coactivator 3 (SRC3; NCOA3).
Chemotherapeutic agents that target estrogen receptor alpha (ERa and growth factor signaling systems have been extensively pursued and developed for a long time (1-4). However, one of the most pressing limitations of currently established chemotherapeutic agents for breast cancer is the fact that breast cancers frequently acquire resistance to antiestrogens (5, 6). Nuclear receptors (NR) and other hormone receptors mediate their cellular effects in part through the interaction with coactivators which increase their transcriptional activity. The best characterized coactivator family is the steroid receptor coactivator (SRC) family (7). Given the central role that SRC-3 plays in breast and other cancers, the search for small molecule agents that target SRC-1 and SRC-3 represent an innovative and potentially effective strategy to identify agents to treat hormone-refractory breast cancers and other cancers where these coactivators are overexpressed. Compounds that target the function of steroid receptor coactivator 3 (SRC-3) protein promise to be different because cancer cells are less likely to bypass the comprehensive disruption of multiple growth factor signaling systems that result from the loss of SRC-3 function. In contrast to the goal of screens that seek to interfere with NR-coactivator interactions, the work proposed here aims to identify compounds that specifically target the coactivators themselves. This approach offers to be more broadly applicable. For instance, SRC-1 or SRC-3 typically remains overexpressed in ER negative cancers or acts as a coactivator for other oncogenic transcription factors (8). SMIs that target ERa, on the other hand are largely predicted to duplicate the biological action of antiestrogens such as tamoxifen.
1. Arteaga, C.L., A.K. Tandon, D.D. Von Hoff, and C.K. Osborne, Transforming growth factor beta: potential autocrine growth inhibitor of estrogen receptor-negative human breast cancer cells. Cancer Res, 1988. 48(14): p. 3898-904.
2. Ciardiello, F., T. Troiani, F. Caputo, M. De Laurentiis, G. Tortora, G. Palmieri, F. De Vita, M.R. Diadema, M. Orditura, G. Colantuoni, C. Gridelli, G. Catalano, S. De Placido, and A.R. Bianco, Phase II study of gefitinib in combination with docetaxel as first-line therapy in metastatic breast cancer. Br J Cancer, 2006. 94(11): p. 1604-9.
3. Goldstein, D., S.M. Bushmeyer, P.L. Witt, V.C. Jordan, and E.C. Borden, Effects of type I and II interferons on cultured human breast cells: interaction with estrogen receptors and with tamoxifen. Cancer Res, 1989. 49(10): p. 2698-702.
4. Riggins, R.B., A. Zwart, R. Nehra, and R. Clarke, The nuclear factor kappa B inhibitor parthenolide restores ICI 182,780 (Faslodex; fulvestrant)-induced apoptosis in antiestrogen-resistant breast cancer cells. Mol Cancer Ther, 2005. 4(1): p. 33-41.
5. Chen, F.L., W. Xia, and N.L. Spector, Acquired resistance to small molecule ErbB2 tyrosine kinase inhibitors. Clin Cancer Res, 2008. 14(21): p. 6730-4.
6. Riggins, R.B., M.M. Mazzotta, O.Z. Maniya, and R. Clarke, Orphan nuclear receptors in breast cancer pathogenesis and therapeutic response. Endocr Relat Cancer, 2010. 17(3): p. R213-31.
7. Lonard, D.M., R. Kumar, and B.W. O'Malley, Minireview: the SRC family of coactivators: an entree to understanding a subset of polygenic diseases? Mol Endocrinol, 2010. 24(2): p. 279-85.
8. Xu, J., R.C. Wu, and B.W. O'Malley, Normal and cancer-related functions of the p160 steroid receptor co-activator (SRC) family. Nat Rev Cancer, 2009. 9(9): p. 615-30.
dose response, quadruplicate, steroid receptor coactivator 3, SRC3, nuclear receptor coactivator 3, NCOA3, amplified in breast cancer 1 protein, AIB1, cancer, breast cancer, inhibit, inhibitor, coactivator, lumi, luminescence, HTS, high throughput screen, 1536, Scripps Florida, The Scripps Research Institute Molecular Screening Center, SRIMSC, Molecular Libraries Probe Production Centers Network, MLPCN.
The purpose of this assay is to determine dose response curves for the top 250 compounds identified as active in a set of experiments entitled, "Luminescence-based cell-based primary high throughput screening assay to identify inhibitors of the Steroid Receptor Coactivator 3 (SRC3; NCOA3)" (AID 588352), that confirmed activity in a set of experiments entitled, "Luminescence-based cell-based high throughput confirmation assay for inhibitors of the Steroid Receptor Coactivator 3 (SRC3; NCOA3)" (AID 588792), and were inactive in a set of experiments entitled, "Counterscreen for inhibitors of the Steroid Receptor Coactivator 3 (SRC3; NCOA3): Luminescence-based cell-based high throughput assay to identify inhibitors of the Herpes Virus Virion Protein 16 (VP16)" (AID 588794).
In this assay, HEK293 cells are transfected with a GAL4-responsive reporter plasmid (pGL4.31, Promega) and an expression vector encoding SRC3 fused to the DNA-binding domain of GAL4 (pBIND-SRC-3). The ability of compounds to reduce coactivator transcriptional activity is assessed by measuring luciferase expression from the reporter gene plasmid. As designed, compounds that inhibit the ability of SRC3 to induce transcription will lead to a decrease in expression of the luciferase gene, resulting in reduced well luminescence. Compounds are tested in quadruplicate using a 10-point 1:3 dilution series starting at a nominal test concentration of 36 uM.
Seven million HEK293 cells were seeded into T-175 flasks containing 23 mLs of DMEM media supplemented with 10% v/v fetal bovine serum and 1% v/v Anti-Anti. Flasks were then incubated for 48 hours at 37 C, 5% CO2 and 95% relative humidity (RH). The day prior to the assay, cells were harvested using TrypLE, resuspended in fresh media at a density of 1 million cells per mL and seeded into new T-175 flasks (23 mL per flask). After allowed to attach for one hour at 37 C, 5% CO2 and 95% RH, cells were transfected with 1 mL of preincubated mix of serum-free OptiMEM containing 23 ug of the pGL4.31 reporter plasmid, 2.3 ug of pBIND-SRC3 vector, and 80 uL of transfection reagents. Twenty four hours post transfection, cells were harvested using 5 mL of TrypLE and resuspended at a concentration of 750,000 cells per mL in phenol-red free DMEM media supplemented as described above.
The assay was started by dispensing 5 uL of cell suspension into each well of a white, solid-bottom 1536-well plate using a flying reagent dispenser (3,750 cells per well). The first two columns received cells transfected with reporter plasmid and an empty pBIND vector as a control for background luminescence. Cells were then treated with 18 nL/well of test compounds, DMSO as a negative control (final concentration 0.36%), or Gossypol as a positive control (36 uM final) using a PinTool transfer unit (GNF). Plates were then placed in the incubator at 37 C, 5% CO2 and 95%RH. Twenty four hours later, plates were removed from the incubator and equilibrated to room temperature for 10 minutes. Luciferase activity was detected by adding 5 uL per well of ONE-Glo luciferase detection reagent. After a 15 minute incubation time, light emission was measured using the ViewLux plate reader (PerkinElmer). The percent inhibition of each test compound was calculated as follows:
%_Inhibition = ( 1 - ( median_positive_control - test_compound ) / ( median_positive_control - median_negative_control ) * 100
Test_Compound is defined as wells containing test compound treated cells.
Positive_Control is defined as wells containing Gossypol treated cells.
Negative_Control is defined as wells containing DMSO treated cells.
PubChem Activity Outcome and Score:
For each test compound, percent inhibition was plotted against compound concentration. A four parameter equation describing a sigmoidal dose-response curve was then fitted with adjustable baseline using Assay Explorer software (Symyx Technologies Inc). The reported IC50 values were generated from fitted curves by solving for the X-intercept value at the 50% inhibition level of the Y-intercept value. In cases where the highest concentration tested (i.e. 36 uM) did not result in greater than 50% inhibition, the IC50 was determined manually as greater than 36 uM. Compounds with an IC50 greater than 10 uM were considered inactive. Compounds with an IC50 equal to or less than 10 uM were considered active.
Any compound with a percent activity value < 50% at all test concentrations was assigned an activity score of zero. Any compound with a percent activity value >= 50% at any test concentration was assigned an activity score greater than zero.
Activity score was then ranked by the potency of the compounds with fitted curves, with the most potent compounds assigned the highest activity scores.
The PubChem Activity Score range for active compounds is 100-71, and for inactive compounds 70-0.
List of Reagents:
HEK-293 cells (ATCC, part CRL-1573)
DMEM media (Invitrogen, part 11965)
Fetal Bovine Serum (Hyclone, part SH30088.03)
Anti-Anti (Gibco, part 15240)
TrypLE (Invitrogen, part 12604)
T-175 flasks (Falcon, part 353112)
pGL4.31 (Promega, part C935A)
pBIND-SRC3 (Assay Provider)
TransIT 293 transfection reagent (Mirus Corporation, part MIR-2700)
ONE-Glo luciferase reagent (Promega, part E6130)
White, solid-bottom 1536-well plates (Greiner, part 789173)
Due to the increasing size of the MLPCN compound library, this assay may have been run as two or more separate campaigns, each campaign testing a unique set of compounds. In this case the results of each separate campaign were assigned "Active/Inactive" status based upon that campaign's specific compound activity cutoff value. All data reported were normalized on a per-plate basis. Possible artifacts of this assay can include, but are not limited to: dust or lint located in or on wells of the microtiter plate, cytotoxic compounds, compounds that perturb the UAS/GAL4 reporter system, and compounds that quench, inhibit, stabilize, or emit luminescence within the well. All test compound concentrations reported are nominal; the specific concentration for a particular test compound may vary based upon the actual sample provided by the MLSMR. The MLSMR was not able to provide all compounds selected for testing in this assay.
BAO: version: 1.4b1090
BAO: bioassay specification: assay stage: confirmatory
BAO: bioassay specification: assay biosafety level: bsl1
BAO: assay format: cell-based format
BAO: bioassay specification: assay measurement type: endpoint assay
BAO: bioassay specification: assay readout content: assay readout method: regular screening
BAO: bioassay specification: assay readout content: content readout type: single readout
BAO: meta target: molecular target: protein target: transcription factor
BAO: meta target: biological process target: regulation of molecular function
BAO: meta target detail: binding reporter specification: interaction: protein-small molecule
BAO: assay design: inducible reporter: luciferase induction
BAO: detection technology: luminescence: chemiluminescence
Assay: Dictionary: Version: 0.1
Assay: CurveFit : Equation: =( ( [Maximal Response] * [Concentration]^[Hill Slope] ) / ( [Inflection Point Concentration]^[Hill Slope] + [Concentration]^[Hill Slope] ) ) + [Baseline Response]
Assay: CurveFit : Mask: Excluded Points
* Activity Concentration. ** Test Concentration.
Data Table (Concise)