An Update on the Genetic Drivers of Corticotroph Tumorigenesis.

The genetic landscape of corticotroph tumours of the pituitary gland has dramatically changed over the last 10 years. Somatic changes in the gene account for the most common genetic defect in corticotrophinomas, especially in females, while variants in or are associated with a subset of aggressive tumours. Germline defects have also been identified in patients with Cushing's disease: some are well-established (), while others are rare and could represent coincidences.

Intact GR dimerization is critical for restraining plasma ACTH levels during chronic psychosocial stress.

Male C57BL/6N mice exposed to the chronic subordinate colony housing (CSC; 19 days) paradigm, a preclinically validated model of chronic psychosocial stress, are characterized by unaffected basal morning plasma corticosterone (CORT) concentrations despite adrenal and pituitary hyperplasia and increased adrenocorticotropic hormone (ACTH) plasma concentrations, compared with single-housed control (SHC) mice. However, as CSC mice are still able to show an increased CORT secretion towards novel heterotypic stressors, these effects might reflect an adaptation rather than a functional breakdown of general hypothalamus-pituitary-adrenal (HPA) axis functionality. In the present study we used male mice of a genetically modified mouse line, to investigate whether genetically-driven ACTH overexpression compromises adaptational processes occurring at the level of the adrenals during CSC exposure.

Aggressive Pituitary Tumors and Pituitary Carcinomas: From Pathology to Treatment.

Aggressive pituitary tumors (APTs) and pituitary carcinomas (PCs) are heterogeneous with regard to clinical presentation, proliferative markers, clinical course, and response to therapy. Half of them show an aggressive course only many years after the first apparently benign presentation. APTs and PCs share several properties, but a Ki67 index greater than or equal to 10% and extensive p53 expression are more prevalent in PCs.

TP53 mutations in functional corticotroph tumors are linked to invasion and worse clinical outcome.

Corticotroph macroadenomas are rare but difficult to manage intracranial neoplasms. Mutations in the two Cushing's disease mutational hotspots USP8 and USP48 are less frequent in corticotroph macroadenomas and invasive tumors. There is evidence that TP53 mutations are not as rare as previously thought in these tumors.

Improved pasireotide response in USP8 mutant corticotroph tumours in vitro.

Cushing's disease is a rare but devastating and difficult to manage condition. The somatostatin analogue pasireotide is the only pituitary-targeting pharmaceutical approved for the treatment of Cushing's disease but is accompanied by varying efficacy and potentially severe side effects. Finding means to predict which patients are more likely to benefit from this treatment may improve their management.

HIF1α is a direct regulator of steroidogenesis in the adrenal gland.

Endogenous steroid hormones, especially glucocorticoids and mineralocorticoids, derive from the adrenal cortex, and drastic or sustained changes in their circulatory levels affect multiple organ systems. Although hypoxia signaling in steroidogenesis has been suggested, knowledge on the true impact of the HIFs (Hypoxia-Inducible Factors) in the adrenocortical cells of vertebrates is scant. By creating a unique set of transgenic mouse lines, we reveal a prominent role for HIF1α in the synthesis of virtually all steroids in vivo.

Heat Shock Protein 90 as a Prognostic Marker and Therapeutic Target for Adrenocortical Carcinoma.

Adrenocortical carcinoma (ACC) is a rare tumor entity with restricted therapeutic opportunities. HSP90 (Heat Shock Protein 90) chaperone activity is fundamental for cell survival and contributes to different oncogenic signaling pathways. Indeed, agents targeting HSP90 function have shown therapeutic efficacy in several cancer types.

Driver mutations in USP8 wild-type Cushing's disease.

Background: Medical treatment in Cushing's disease (CD) is limited due to poor understanding of its pathogenesis. Pathogenic variants of ubiquitin specific peptidase 8 (USP8) have been confirmed as causative in around half of corticotroph tumors. We aimed to further characterize the molecular landscape of those CD tumors lacking USP8 mutations in a large cohort of patients.

Inherited Forms of Primary Hyperaldosteronism: New Genes, New Phenotypes and Proposition of A New Classification.

Primary aldosteronism is a common cause of endocrine hypertension. It results from the excess production of aldosterone by the adrenal cortex and is related to increased morbidity and mortality. Most cases of PA are sporadic but inherited patterns of the disease have been reported in the literature.