Assay Method Information

Assay Name:  The screening assay for Wnt activity
Description:  The screening assay for Wnt activity is described as follows. Reporter cell lines can be generated by stably transducing cancer cell lines (e.g., colon cancer) or primary cells (e.g., IEC-6 intestinal cells) with a lentiviral construct that includes a Wnt-responsive promoter driving expression of the firefly luciferase gene.SW480 colon carcinoma cells were transduced with a lentiviral vector expressing luciferase with a human Sp5 promoter consisting of a sequence of eight TCF/LEF binding sites. SW480 cells stably expressing the Sp5-Luc reporter gene and a hygromycin resistance gene were selected by treatment with 150 μg/ml of hygromycin for 7 days. These stably transduced SW480 cells were expanded in cell culture and used for all further screening activities. For Sp5-Luc reporter gene assays, the cells were plated at 10,000 cells/well in 96-well plates with growth medium containing 10% fetal calf serum and incubated overnight at 37° C. and 5% CO2. Each compound was dissolved in DMSO as a 10 mM stock in standard j-vials and used to prepare compound source plates in dose-response format with 3-fold serial dilutions and a 10 mM top concentration. Compound transfer from serially diluted source plates to assay plates containing the cells was accomplished using a pintool (Multimek 96, Beckman equipped with V&P Scientific FP1S50H pins) based liquid handling protocol. This protocol used a slotted pin to transfer 50 nl of compound from a source plate well to an assay plate well containing 50 μl of cells in growth medium. The 1000-fold dilution resulted in a final DMSO concentration of 0.1% on the cells in each well. Control wells received 50 nl of DMSO treatment for normalization and calculating IC50 values. The treated cells were incubated at 37° C. and 5% CO2 for an additional forty-two hours. Following incubation, the growth medium was removed and 50 μl of BrightGlo luminescence reagent (Promega) was added to each well of the 96-well assay plates. The plates were placed on an orbital shaker for 5 min and then luminescence was quantified on the Victor3 (Perkin Elmer) plate reader. Readings were normalized to DMSO only treated cells, and normalized activities were utilized for IC50 calculations using the dose-response log (inhibitor) vs. response-variable slope (four parameters) nonlinear regression feature available in GraphPad Prism 5.0 or 6.0.
Affinity data for this assay
 

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