IWP 4 is an inhibitor of Wnt production. IWP 4 impairs Wnt pathway activity (IC50 = 25 nM) by inactivating Porcupine, a membrane-bound acyltransferase responsible for attaching a palmitoyl group to Wnt proteins, which is essential to Wnt signaling and Wnt secretion. The Wnt family of signaling proteins is involved in most aspects of embryonic development and postembryonic tissue homeostasis. Hyperactivation of the Wnt/β-catenin pathway induces premature senescence of stem cells and age-related loss of stem cell function. In cancer, hyperactivation of the Wnt/β-catenin pathway often exists along with mutations in other cell growth regulatory genes, which results in aberrant cell growth. Thus, IWP 4 could serve a useful tool for researching tissue regeneration and Wnt ligand-dependent tumors. IWP 4 has been used for inducing cardiomyocyte differentiation from human pluripotent stem cells.

References:

1. Chen B, Dodge ME, Tang W, et al. Small molecule-mediated disruption of Wnt-dependent signaling in tissue regeneration and cancer. Nature Chemical Biology, 2009, 5(2): 100-107.

2. Lian X, Hsiao C, Wilson G, et al. Robust cardiomyocyte differentiation from human pluripotent stem cells via temporal modulation of canonical Wnt signaling. Proceedings of the National Academy of Sciences of the United States of America, 2012, 109(27): E1848-1857.