Mammary anlagen are formed in the embryo as a derivative of the epidermis, a process that is controlled by Lef-1 and therefore possibly by β-catenin. To investigate the role of βcatenin signaling in mammary alveolar epithelium, we have stabilized endogenous β-catenin in differentiating alveolar epithelium through the deletion of exon 3 (amino acids 5-80) of the β-catenin gene. This task was accomplished in mice carrying a floxed β-catenin gene and a Cre transgene under control of the mammary-specific whey acidic protein (WAP) gene promoter or the mouse mammary tumor virus-long terminal repeat (MMTV-LTR). Stabilized β-catenin was obtained during the first pregnancy, and its presence resulted in the dedifferentiation of alveolar epithelium followed by a transdifferentiation into epidermal and pilar structures. Extensive squamous metaplasia, but no adenocarcinomas, developed upon β-catenin activation during pregnancy and persisted throughout involution. These data demonstrate that the activation of βcatenin signaling induces a program that results in loss of mammary epithelial cell differentiation and induction of epidermal structures.
|Original language||English (US)|
|Number of pages||6|
|Journal||Proceedings of the National Academy of Sciences of the United States of America|
|State||Published - Jan 8 2002|
- Cell identity
- Mammary gland
ASJC Scopus subject areas