Potency assay (cells):
In HEK293 cells, XAV939 inhibited SuperTopFlash-luciferase reporter expression (Wnt/B-catenin-dependent expression).
Target engagement assay (cells):
In cells, modified XAV939 was used to identify targets using iTRAQ chemoproteomics; identified targets included TNKS, TNKS2, PARP1, and PARP2. In CETSA experiments, XAV939 interacts with PARP1, confirming that this compound targets PARP family proteins beyond TNKS1 and TNSK2.