Investigation of BRAF and CTNNB1 activating mutations in adrenocortical tumors

Activating mutations of the BRAF oncogene play a central role in the development of various cancer types, but their role in human adrenocortical tumors is unknown. At variance, activating mutations of another oncogene, CTNNB1, which encodes beta-catenin, have been shown to be common events in both benign and malignant adrenocortical tumors.

To investigate the prevalence of BRAF and CTNNB1 activating mutations in sporadic adrenocortical tumors.

Tissue samples from 15 adrenocortical carcinomas and 41 adrenocortical adenomas were investigated for the presence of BRAF and CTNNB1 activating mutations by PCR amplification and direct sequencing.

An advanced invasive non-functioning adrenocortical carcinoma carried a somatic heterozygous BRAF V600E mutation, while 4 functioning and 4 non-functioning adenomas and 3 functioning carcinomas carried different CTNNB1 activating mutations.

Activating BRAF somatic mutations may be occasionally found in advanced adrenocortical carcinomas, while CTNNB1 activating mutations are early and common events in adrenal tumorigenesis.