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.

Diagnosis and Treatment of Parasellar Lesions.

The parasellar region, located around the sella turcica, is an anatomically complex area representing a crossroads for important adjacent structures. Several lesions, including tumoral, inflammatory vascular, and infectious diseases may affect this area. Although invasive pituitary tumors are the most common neoplasms encountered within the parasellar region, other tumoral (and cystic) lesions can also be detected.

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.

Aggressive and Malignant Prolactinomas.

Prolactin-secreting tumors (prolactinomas) represent the most common pituitary tumor type, accounting for 47-66% of functional pituitary tumors. Prolactinomas are usually benign and controllable tumors as they express abundant levels of dopamine type 2 receptor (D2), and can be treated with dopaminergic drugs, effectively reducing prolactin levels and tumor volume. However, a proportion of prolactinomas exhibit aggressive features (including invasiveness, relevant growth despite adequate dopamine agonist treatment, and recurrence potential) and few may exhibit metastasizing potential (carcinomas).

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.

PATHOGENESIS OF CUSHING DISEASE: AN UPDATE ON THE GENETICS OF CORTICOTROPINOMAS.

Objective: Cushing disease is a rare severe condition caused by pituitary tumors that secrete adrenocorticotropic hormone (ACTH), leading to excessive endogenous glucocorticoid production. Tumors causing Cushing disease, also called corticotropinomas, are typically monoclonal neoplasms that mainly occur sporadically.

Methods: Literature review.

The USP8 mutational status may predict long-term remission in patients with Cushing's disease.

Objective: Almost half of the cases of Cushing's disease (CD) tumours carry recurrent activating somatic mutations in the ubiquitin-specific protease eight gene (USP8). The USP8 mutational status could predict remission in patients with CD, so our objective was to correlate the presence of somatic USP8 mutations with the rate of recurrence after transsphenoidal surgery (TSS) retrospectively.

Design: Biochemical, radiological and clinical data were retrospectively assessed in 48 patients.

Somatic mutations are frequent events in corticotroph tumor progression causing Nelson's tumor.

Objective: Somatic mutations in the ubiquitin-specific protease 8 () gene are frequent in corticotroph tumors causing Cushing's disease (CD). Corticotroph tumor progression, the so-called Nelson's syndrome (NS), is a potentially life-threatening complication of bilateral adrenalectomy in patients with refractory CD that is caused by the development of an ACTH-secreting tumor of the pituitary gland. Whether alterations are also present in progressive Nelson's tumors has not been studied in detail so far.

PRKACA Somatic Mutations Are Rare Findings in Aldosterone-Producing Adenomas.

Context: Somatic mutations have been found causative for endocrine autonomy in aldosterone-producing adenomas (APAs). Whereas mutations of PRKACA (catalytic subunit of protein kinase A) have been identified in cortisol-producing adenomas, the presence of PRKACA variants in APAs is unknown, especially in those that display cosecretion of cortisol.

Objective: The objective of the study was to investigate PRKACA somatic variants identified in APA cases.

The Gene of the Ubiquitin-Specific Protease 8 Is Frequently Mutated in Adenomas Causing Cushing's Disease.

Context: We have recently reported somatic mutations in the ubiquitin-specific protease USP8 gene in a small series of adenomas of patients with Cushing's disease.

Objective: To determine the prevalence of USP8 mutations and the genotype-phenotype correlation in a large series of patients diagnosed with Cushing's disease.

Design: We performed a retrospective, multicentric, genetic analysis of 134 functioning and 11 silent corticotroph adenomas using Sanger sequencing.

A microRNA signature associated with early recurrence in breast cancer.

Recurrent breast cancer occurring after the initial treatment is associated with poor outcome. A bimodal relapse pattern after surgery for primary tumor has been described with peaks of early and late recurrence occurring at about 2 and 5 years, respectively. Although several clinical and pathological features have been used to discriminate between low- and high-risk patients, the identification of molecular biomarkers with prognostic value remains an unmet need in the current management of breast cancer.

Serum protein levels following surgery in breast cancer patients: a protein microarray approach.

Surgery is the primary treatment for non-metastatic breast cancer. However, the risk of early recurrence remains after surgical removal of the primary tumor. Recurrence is suggested to result from hidden micrometastatic foci, which are triggered to escape from dormancy by surgical resection of the primary tumor.

VRK2 anchors KSR1-MEK1 to endoplasmic reticulum forming a macromolecular complex that compartmentalizes MAPK signaling.

The spatial and temporal regulation of intracellular signaling is determined by the spatial and temporal organization of complexes assembled on scaffold proteins, which can be modulated by their interactions with additional proteins as well as subcellular localization. The scaffold KSR1 protein interacts with MAPK forming a complex that conveys a differential signaling in response to growth factors. The aim of this work is to determine the unknown mechanism by which VRK2A downregulates MAPK signaling.

Lack of evidence for KRAS oncogenic mutations in triple-negative breast cancer.

Background: Mutational analysis of the KRAS gene has recently been established as a complementary in vitro diagnostic tool for the identification of patients with colorectal cancer who will not benefit from anti-epidermal growth factor receptor (EGFR) therapies. Assessment of the mutation status of KRAS might also be of potential relevance in other EGFR-overexpressing tumors, such as those occurring in breast cancer. Although KRAS is mutated in only a minor fraction of breast tumors (5%), about 60% of the basal-like subtype express EGFR and, therefore could be targeted by EGFR inhibitors.

The functional interaction of 14-3-3 proteins with the ERK1/2 scaffold KSR1 occurs in an isoform-specific manner.

Identifying 14-3-3 isoform-specific substrates and functions may be of broad relevance to cell signaling research because of the key role played by this family of proteins in many vital processes. A multitude of ligands have been identified, but the extent to which they are isoform-specific is a matter of debate. Herein we demonstrate, both in vitro and in vivo, a specific, functionally relevant interaction of human 14-3-3gamma with the molecular scaffold KSR1, which is mediated by the C-terminal stretch of 14-3-3gamma.