Evaluation of adrenal tumors from 118 adult patients demonstrated an increase in CTNNB1 mutations and abnormal β-catenin accumulation in both adrenocortical adenoma and ACC.
Mutations of the β-catenin gene (CTNNB1), which lead to constitutive activation of Wnt signaling, have recently been described in adrenocortical adenomas (AA) and carcinomas (ACC).
ENC1 was specifically overexpressed in three of three AA harboring CTNNB1 point mutations. mRNA expression and protein levels of RALBP1, PDE2A, and ENC1 were decreased in a dose-dependent manner in H295R cells after treatment with PKF115-584 or PNU74654.
The Wnt/beta-catenin pathway is activated in PPNADs and ACAs with PRKAR1A mutations, suggesting a cross talk between the cAMP and Wnt/beta-catenin pathways in ACT development.
Activating mutations of exon 3 of the beta-catenin gene are frequent in adrenocortical adenomas, and further characterization of the Wnt/beta-catenin signalling pathway should lead to a better understanding of adrenal tumourigenesis.
In adrenocortical adenomas, beta-catenin alterations are more frequent in nonfunctioning tumors, suggesting that beta-catenin pathway activation might be mostly involved in the development of nonsecreting adrenocortical adenomas and adrenocortical carcinomas.