IGF antagonizes the Wnt/β-Catenin pathway and promotes differentiation of extra-embryonic endoderm.

Mouse F9 teratocarcinoma cells are an established model for the differentiation of extra-embryonic endoderm (ExEn). Primitive endoderm, parietal and visceral endoderm can be generated by stimulation of F9 cells with retinoic acid and dibutyryl cyclic adenosine monophosphate. Here we show that Wnt/β-Catenin signaling is down-regulated during ExEn differentiation in F9 cells and that the inhibition of the Wnt pathway promotes differentiation of the three extra-embryonic endoderm lineages.

Loss of Xenopus cadherin-11 leads to increased Wnt/β-catenin signaling and up-regulation of target genes c-myc and cyclin D1 in neural crest.

Xenopus cadherin-11 (Xcadherin-11) is an exceptional cadherin family member, which is predominantly expressed in cranial neural crest cells (NCCs). Apart from mediating cell-cell adhesion it promotes cranial NCC migration by initiating filopodia and lamellipodia formation. Here, we demonstrate an unexpected function of Xcadherin-11 in NCC specification by interfering with canonical Wnt/β-catenin signaling.