Wnt/β-catenin signalling in adrenal physiology and tumour development.

Wnt/β-catenin signalling plays essential roles during embryonic development and in adult tissue homeostasis. Canonical signalling through Wnt secreted ligands relies on the control of β-catenin cytoplasmic accumulation and translocation to the nucleus. In this compartment, β-catenin serves as a transcription coactivator for transcription factors such as Lef/Tcf or some nuclear receptors. Constitutive Wnt signalling resulting from inactivation of inhibitors of the pathway or from activating mutations in β-catenin, triggers tumour development in a number of tissues. Analysis of patients' samples and genetically engineered mouse models has shown that Wnt signalling was involved in adrenal development and tumourigenesis. This review will summarise all these recent findings and will focus on some of the mechanisms that may lead to aberrant accumulation of β-catenin in adrenocortical tumours.