Characterisation of a variant linked to cortisol-producing adrenocortical adenoma
Abstract
Objective: Adrenocortical adenomas are frequent in the general population and can be associated with autonomous cortisol excess, increasing morbidity and mortality. Altered cAMP/PKA signalling is common in sporadic cortisol-producing adenomas, typically due to somatic activating mutations in the catalytic subunit α of PKA (PRKACA) or the G-protein α subunit, Gαs (GNAS), which activate cAMP signalling. We previously identified a novel p.Lys58Gln GNAS somatic variant in a patient with a 5.3 cm adenoma and overt Cushing's syndrome. This novel mutation was not charactersised before but provided enough evidence to warrant further investigation.
Design and methods: Using HEK293 cells depleted of GNAS, we established wild-type (WT) Gαs and Gαs-Lys58Gln stable cell lines and evaluated adrenocorticotropic hormone (ACTH) receptor signalling using a cAMP GloSensor assay, measured CREB transcription factor phosphorylation (pCREB) by AlphaLISA and assessed CRE luciferase reporter activity. Cell viability and apoptosis were also assessed over 5 days.
Results: The Gαs-Lys58Gln variant showed a significantly higher basal cAMP, pCREB and CRE luciferase reporter concentration and a greater response to ACTH (0-10 nM, P < 0.001) compared to WT Gαs. The variant had no effect on ligand potency. There was also significantly enhanced cell viability and apoptosis in cells with the Gαs-Lys58Gln variant.
Conclusions: In conclusion, our study demonstrated that the Gαs-Lys58Gln variant is associated with constitutive activation of GNAS signalling, similar to Arg201 mutations previously reported in adrenocortical adenomas, potentially representing a new pathogenic mechanism in a subset of patients with adrenal Cushing syndrome. This variant may also affect cell proliferation and requires further study.
Date
2025-05-16
Type
Article
Subject
Endocrinology, Mutation, Adrenal gland neoplasms, Endocrine gland neoplasms, Endocrinology
Collections
Citation
Jamaluddin A, Wyatt R, Pasaliu A, Ruggles O, Calebiro D, Gorvin CM, Ronchi CL. Characterisation of a GNAS variant linked to cortisol-producing adrenocortical adenoma. Endocr Oncol. 2025 May 16;5(1):e250009. doi: 10.1530/EO-25-0009.
Journal / Source Title
Endocrine Oncology
DOI
10.1530/EO-25-0009
PMID
40391091
Publisher
Bioscientifica
Publisher’s URL
https://eo.bioscientifica.com/