Endocrine Abstracts

Introduction: Osilodrostat and Metyrapone are two CYP11B1 inhibitors used for the treatment of patients with Cushing syndrome. Despite their common suspected mechanism of action, the comparison of serum steroid profiles determined in HPLC-MS/MS in patients treated by either Osilodrostat or Metyrapone for an ACTH-dependent Cushing syndrome identified higher levels of 11-deoxycortisol and androgens in patients treated by Metyrapone than in those treated by Osilodrostat (F. B...

Introduction: Bilateral macronodular adrenal hyperplasia (BMAH) is a rare aetiology of Cushing syndrome. Familial clustering suggests a genetic cause that was recently confirmed, after identification of inactivating germline mutations in armadillo repeat containing 5 (ARMC5) gene.Clinical case: A 70 years old female admitted due to femoral neck fracture in May 2014, presented central obesity, rubeosis and hypertension. Laboratory work up reveale...

The cAMP signaling pathway plays an important role in cell proliferation and differentiation, and can be altered at multiple levels in endocrine tumors. Its central component is the protein kinase A (PKA). Inactivating mutations of PRKAR1A are observed in CNC (a dominant autosomal hereditary disease responsible for primary pigmented nodular adrenocortical disease, cardiac myxoma and lentiginosis). Most PRKAR1A mutations lead to mRNA unstability and protein degrad...

cAMP/PKA pathway activation is frequently involved in endocrine tumors with overactivity. The Carney complex (CNC) is an autosomal dominant multiple endocrine neoplasia syndrome which associates cardiac myxomas, spotty skin pigmentation and endocrine overactivity. Mutations in the PRKAR1A gene located at 17q22-24 and encoding for the R1A regulatory subunit of protein kinase A have been found in about 60% of CNC. These mutations are heterozygous germline mutations leading to ab...

BackgroundARMC5 is a putative tumor suppressor gene that is frequently mutated in primary bilateral macronodular adrenal hyperplasia (PBMAH), a rare cause of Cushing’s syndrome. The function of ARMC5 is poorly known, aside the fact that it regulates cell apoptosis and adrenal steroidogenesis in by mechanisms still unknown. Tumor suppressor genes play an important role in oxidative stress.MethodsIn this s...

The most frequent molecular alteration in adrenocortical tumors (ACT) is the activation of the Wnt/β-catenin pathway that is associated with poor prognosis in adrenocortical carcinoma. Activating β-catenin mutation (p.S31, p.S37, p.S45, T.41) inhibiting its proteosomal degradation by the canonical destruction complex is responsible for its abnormal activation in roughly 30% of ACT. However, the E3 ubiquitin protein ligase 1, SIAH1 is able to ubiquitinate β-caten...

Introduction: Bilateral macronodular adrenal disease (BMAD) is a genetically heterogeneous disease that can be caused by ARMC5 or KDM1A alterations. Indeed, a germline and somatic event leading to a bi-allelic inactivation of ARMC5 or KDM1A are responsible for 20 and 1% of BMAD cases, respectively. Genetic analysis identified three molecular groups: ARMC5, KDM1A and no genetic cause known to date. Although there is a high h...

Introduction: ARMC5 germline and somatic inactivating mutations were discovered in patients treated by adrenalectomy for hypercortisolism due to primary bilateral macronodular adrenal hyperplasia (PBMAH). Since then, several ARMC5 germline variants have been described in PBMAH patients. Genetic alterations are spread all over ARMC5 coding sequence and many are missense variants. For them, geneticist conclusions are based on in silico predictions. As ...

Background: Cushing’s syndrome, caused by an excess of circulating glucocorticoids, is associated with high morbidity and presents high inter-individual variability. The earlier the diagnosis, the better the treatment effectiveness and the prognosis. Hormone assays, routinely used, contribute to identify Cushing’s syndrome. However, no biomarker is currently available to directly quantify the biological action of glucocorticoids. Blood samples represent an easily obt...

Pituitary adenomas, now called pituitary neuroendocrine tumors (PitNETs), vary in histological type, secretion, invasion and growth speed. A World Health Organization (WHO) histo-prognostic classification was released in 2017. Pituitary tumorigenesis is largely unexplained. Rare germline mutations (MENIN, AIP), and common somatic mutations in somatotroph (GNAS) and corticotroph (USP8) are reported. Recently, genomic analyses have been report...