Method of screening for a compound for inhibitory activity of FN14-tweak interaction
The present disclosure is directed to methods of screening a compound for modulating activity at a TNF-like weak inducer of apoptosis (TWEAK) binding site on a cysteine-rich domain (CRD) of fibroblast growth factor-inducible 14 (Fn14). The present disclosure also provides heterocyclic compounds and pharmaceutically acceptable salts thereof and methods for the prevention, treatment, and amelioration of cell proliferative disorders with these compounds.
1. A method of screening a compound for inhibitory activity of fibroblast growth factor-inducible 14-TNF-like weak inducer of apoptosis (FN14-TWEAK) interaction, the method comprising the following steps:
a) screening the compound using a cell-based luciferase reporter assay, wherein inhibition of luciferase signal following addition of the compound and TWEAK confirm the activity of the compound at the TWEAK binding site on the cysteine-rich domain (CRD) of Fn14;
b) screening the activity of the compound in combination with a purified tumor necrosis factor alpha (TNFα) using a cell-based luciferase reporter assay, wherein lack of inhibition of luciferase signal confirms specificity of the activity of the compound at the TWEAK binding site on the CRD of Fn14: and
c) further screening the compound for activity at the TWEAK binding site on the CRD of Fn14 using a migration assay by measuring inhibition of migration of cells resulting from addition of the compound and purified TWEAK to the migration assay, wherein inhibition of migration of the cells confirms activity of the compound at the TWEAK binding site on the CRD of Fn14.
2. The method of claim 1 further comprising screening the compound to assess non-specific cytotoxicity using a cell viability assay.
3. The method of claim 1 , wherein the compound has an IC 50 of at least 10 μM.
4. The method of claim 1 further comprising performing an ELISA assay with Fn14, a soluble form of TWEAK (sTWEAK), and the compound to calculate the reduction in sTWEAK binding due to the addition of the compound with a standard curve.
5. The method according to claim 1 , wherein the cell-based luciferase reporter assay comprises human embryonic kidney cells.
6. The method according to claim 1 , wherein the cell-based luciferase reporter assay comprises cells that stably co-express full length Fn14 and a firefly luciferase reporter driven by NF-κB response elements.
7. The method according to claim 1 , wherein the migration assay comprises:
culturing cells in medium containing the compound; and
monitoring radial migration of the cells.
8. The method of claim 7 , wherein the cells are glioblastoma or breast cancer cells.
9. The method of claim 1 , wherein the cell-based luciferase reporter assay comprises cells expressing full length Fn14.
10. The method of claim 1 , wherein the cell-based luciferase reporter assay comprises cells expressing a firefly luciferase reporter driven by NF-κB.
11. The method of claim 1 , wherein the migration assay comprises performing a Boyden Chamber assay.