Activation of β-catenin signaling in differentiated mammary secretory cells induces transdifferentiation into epidermis and squamous metaplasias

摘要: Mammary anlagen are formed in the embryo as a derivative of epidermis, process that is controlled by Lef-1 and therefore possibly β-catenin. To investigate role β-catenin signaling mammary alveolar epithelium, we have stabilized endogenous differentiating epithelium through deletion exon 3 (amino acids 5–80) gene. This task was accomplished mice carrying floxed gene Cre transgene under control mammary-specific whey acidic protein (WAP) promoter or mouse tumor virus-long terminal repeat (MMTV-LTR). Stabilized obtained during first pregnancy, its presence resulted dedifferentiation followed transdifferentiation into epidermal pilar structures. Extensive squamous metaplasia, but no adenocarcinomas, developed upon activation pregnancy persisted throughout involution. These data demonstrate induces program results loss epithelial cell differentiation induction