In vitro activity: XMD8-87 is found to be potent in the inhibition of TNK2 phosphorylation. XMD8-87 and XMD16-5 potently inhibit phosphorylation of TNK2 truncation mutations found in solid tumor types.

Kinase Assay: Kinase targets are tested with biochemical enzymatic kinase assays using the SelectScreen Kinase Profiling Service to determine IC50 values. The compounds (XMD8-87) are assayed at 10 concentrations (3-fold serial dilutions starting from 1 μM) at an ATP concentration equal to the ATP Km

Cell Assay: 293T cells expressing TNK2 are plated in 6-well format at a density of 250,000 cells per well 48 hours prior to treatment. Cells are then treated with a 100 μL of XMD8-87 or XMD16-5 at 5 μmol/L and with 9 1:1 serial dilutions down to ≈10 nmol/L. Two additional samples are treated with DMSO only. Cells are then incubated for 6 hours at 37°C. Protein extraction is accomplished by adding 300 μL of lysis buffer to cells after removing media. Plates are gently shaken for 5 minutes at room temperature. Lysates are collected and cleared of incompletely solubilized material by spinning for 10 minutes at maximum speed in a microcentrifuge. Samples are prepared for SDS-PAGE using the EPage loading buffer.