In vitro activity: COTI-2 can potently inhibit the proliferation of all the tested cell lines following 72 h of treatment. COTI-2 is significantly effective at inhibiting tumor cell proliferation in all three cell lines (COLO-205, HCT-15, and SW620). Low concentrations of COTI-2 are active against all human glioblastoma cell lines tested (U87-MG, SNB-19, SF-268, and SF-295). COTI-2 treatment of SHP-77 cells with approximate IC50 concentrations results in the induction of early apoptosis among 40 to 47% of total cells.

Kinase Assay: The activity of COTI-2 against 227 kinases is tested using the AMBIT BIOSCIENCES KINOMESCAN assay. Briefly, streptavidin-coated magnetic beads are treated with biotinylated small molecule ligands for 30 min at 25°C to generate affinity resins for kinase assays. The liganded beads are blocked with excess biotin and washed with blocking buffer (1% BSA, 0.05% Tween 20, 1 mM DTT) to remove unbound ligand and to reduce non-specific binding. Binding reactions are assembled by combining phage lysates, liganded affinity beads, and COTI-2 in 1× binding buffer (20% SeaBlock, 0.17× PBS, 0.05% Tween 20, 6 mM DTT). All reactions are carried out in polystyrene 96-well plates that have been pre-treated with blocking buffer in a final volume of 0.1 mL.

Cell Assay: SHP-77 cells were treate with COTI-2 at various concentrations for 48 h. Cells were then washed twice with 1X cold PBS and stained with Annexin V and 7AAD. Briefly, 5 μl of Annexin V and 7AAD were added to 1 × 105 cells and incubated for 15 min at room temperature in the dark. Then 400 μl of the 1X binding buffer was added to the cells.