A cell-permeable
p-imidobenzamidoquinoline,
endo-diastereomer that is shown to inhibit the activity of TNKS1/PARP5a and TNKS2/PARP5b in
in vitro auto-PARsylation assays (IC
50 = 131 and 56 nM, respectively) and effectively suppress Wnt-stimulated transcription activity in L-Wnt-STF-based reporter assays (IC
50 = 180 nM), while exhibiting little activity against PARP1 or PARP2 (IC
50 >18.75 μM). Although both IWR-1-
endo and XAV939 (Tankyrase1/2 Inhibitor;
>Cat. No. 575545) act as reversible Wnt pathway inhibitors and exhibit similar pharmacological effects both
in vitro and
in vivo, IWR-1-
endo exerts its effect via interaction with Axin, while XAV939 binds TNKS directly.