XAV939, 1 mg

A WNT pathway inhibitor from STEMCELL Technologies, this small molecule selectively inhibits tankyrase (TNKS) 1 and 2 with IC₅₀ values of 11 and 4 nM, respectively. By inhibiting TNKS activity, the compound increases AXIN-GSK3β complex levels and promotes β-catenin degradation in SW480 cells, thereby blocking downstream WNT pathway signaling.

The chemical name is 2-[4-(trifluoromethyl)phenyl]-1,5,7,8-tetrahydrothiopyrano[4,3-d]pyrimidin-4-one (CAS 284028-89-3), with molecular formula C₁₄H₁₁F₃N₂OS and molecular weight 312.3 g/mol. The product is supplied as a crystalline solid with purity ≥ 98% and should be kept stable at -20°C, protected from prolonged light exposure. Reported solubility values are ≤ 6.4 mM in DMSO, approximately 0.15 mg/mL in 1:5 EtOH:PBS (pH 7.2), ~2 mg/mL in DMSO, and ~5 mg/mL in DMF. Stock solutions should be prepared fresh in DMSO, and final DMSO concentration should be kept below 0.1% when added to cell culture to avoid toxicity.

Published research applications include induction of cardiomyogenesis in mesoderm progenitor cells derived from mouse embryonic stem cells and, in combination with the SMAD inhibitors LDN193189 and SB431542, promotion of forebrain fates in human pluripotent stem cell lines. In cancer research contexts, the compound inhibits colony formation in APC-deficient, β-catenin-dependent DLD-1 colorectal cancer cells. The substance is classified as acutely toxic if swallowed (Category 3) and causes serious eye irritation (Category 2A). For research use only.