Extensive expertise in endocrinology: glucose-dependent insulinotropic peptide-dependent Cushing's syndrome.

Thirty years ago, we identified that cortisol secretion in some patients with unilateral adenoma or primary bilateral macronodular adrenal hyperplasia (PBMAH) was stimulated by food intake; this was secondary to the abnormal adrenocortical responsiveness to physiological post-prandial increase in glucose-dependent insulinotropic peptide (GIP). This resulted from the ectopic expression of non-mutated GIP receptor in the pathological adrenal tissues of those patients. Although ectopic GIP receptor (GIPR) was confirmed in a relatively limited number of cases to date, its elucidation leads to the identification of a wide diversity of aberrant G-protein-coupled receptors regulating steroidogenesis and cell proliferation in a high proportion of patients with PBMAH or cortisol-secreting adenomas. In addition, ectopic GIPR was identified in other endocrine tumors including somatotroph pituitary tumors with paradoxical growth hormone response to oral glucose, medullary thyroid carcinomas, and other neuroendocrine tumors. The first molecular pathogenic mechanism responsible for ectopic GIPR expression was elucidated in unilateral GIP-dependent adenomas in which somatic duplication and rearrangements in chromosome region 19q13.32 containing the GIPR locus lead to increased expression of GIPR which was enhanced by the activity of a glucocorticoid response element. Recently, germline lysine demythylase 1A (KDMIA) mutations combined with somatic chromosome 1p deletions were found to be specifically responsible for ectopic GIPR in sporadic or familial GIP-dependent PBMAH and can be associated with adrenal myelolipoma, monoclonal gammopathy of unknown significance (MGUS), or multiple myeloma. Screening for ectopic GIPR should be conducted in all patients with PBMAH; genetic studies to identify KDM1A mutations should be offered to such patients in order to detect affected members and provide early detection of PBMAH and other potential associated neoplasias. The elucidation of GIP-dependent Cushing's syndrome (CS) illustrates that careful bedside phenotyping of rare conditions can lead to identification of genetically determined diseases requiring personalized approaches to investigation and therapy.

Lacroix A 《-》

Loss of KDM1A in GIP-dependent primary bilateral macronodular adrenal hyperplasia with Cushing's syndrome: a multicentre, retrospective, cohort study.

GIP-dependent primary bilateral macronodular adrenal hyperplasia with Cushing's syndrome is caused by aberrant expression of the GIP receptor in adrenal lesions. The bilateral nature of this disease suggests germline genetic predisposition. We aimed to identify the genetic driver event responsible for GIP-dependent primary bilateral macronodular adrenal hyperplasia with Cushing's syndrome. We conducted a multicentre, retrospective, cohort study at endocrine hospitals and university hospitals in France, Canada, Italy, Greece, Belgium, and the Netherlands. We collected blood and adrenal samples from patients who had undergone unilateral or bilateral adrenalectomy for GIP-dependent primary bilateral macronodular adrenal hyperplasia with Cushing's syndrome. Adrenal samples from patients with primary bilateral macronodular adrenal hyperplasia who had undergone an adrenalectomy for overt or mild Cushing's syndrome without evidence of food-dependent cortisol production and those with GIP-dependent unilateral adrenocortical adenomas were used as control groups. We performed whole genome, whole exome, and targeted next generation sequencing, and copy number analyses of blood and adrenal DNA from patients with familial or sporadic disease. We performed RNA sequencing on adrenal samples and functional analyses of the identified genetic defect in the human adrenocortical cell line H295R. 17 patients with GIP-dependent primary bilateral macronodular adrenal hyperplasia with Cushing's syndrome were studied. The median age of patients was 43·3 (95% CI 38·8-47·8) years and most patients (15 [88%]) were women. We identified germline heterozygous pathogenic or most likely pathogenic variants in the KDM1A gene in all 17 patients. We also identified a recurrent deletion in the short p arm of chromosome 1 harboring the KDM1A locus in adrenal lesions of these patients. None of the 29 patients in the control groups had KDM1A germline or somatic alterations. Concomitant genetic inactivation of both KDM1A alleles resulted in loss of KDM1A expression in adrenal lesions. Global gene expression analysis showed GIP receptor upregulation with a log2 fold change of 7·99 (95% CI 7·34-8·66; p=4·4 × 10-125), and differential regulation of several other G protein-coupled receptors in GIP-dependent primary bilateral macronodular hyperplasia samples compared with control samples. In vitro pharmacological inhibition and inactivation of KDM1A by CRISPR-Cas9 genome editing resulted in an increase of GIP receptor transcripts and protein in human adrenocortical H295R cells. We propose that GIP-dependent primary bilateral macronodular adrenal hyperplasia with Cushing's syndrome results from a two-hit inactivation of KDM1A, consistent with the tumour suppressor gene model of tumorigenesis. Genetic testing and counselling should be offered to these patients and their relatives. Agence Nationale de la Recherche, Fondation du Grand défi Pierre Lavoie, and the French National Cancer Institute.

Chasseloup F ，Bourdeau I ，Tabarin A ，Regazzo D ，Dumontet C ，Ladurelle N ，Tosca L ，Amazit L ，Proust A ，Scharfmann R ，Mignot T ，Fiore F ，Tsagarakis S ，Vassiliadi D ，Maiter D ，Young J ，Lecoq AL ，Deméocq V ，Salenave S ，Lefebvre H ，Cloix L ，Emy P ，Dessailloud R ，Vezzosi D ，Scaroni C ，Barbot M ，de Herder W ，Pattou F ，Tétreault M ，Corbeil G ，Dupeux M ，Lambert B ，Tachdjian G ，Guiochon-Mantel A ，Beau I ，Chanson P ，Viengchareun S ，Lacroix A ，Bouligand J ，Kamenický P ... -  《-》

Clinical, Pathophysiologic, Genetic, and Therapeutic Progress in Primary Bilateral Macronodular Adrenal Hyperplasia.

Patients with primary bilateral macronodular adrenal hyperplasia (PBMAH) usually present bilateral benign adrenocortical macronodules at imaging and variable levels of cortisol excess. PBMAH is a rare cause of primary overt Cushing's syndrome but may represent up to one-third of bilateral adrenal incidentalomas with evidence of cortisol excess. The increased steroidogenesis in PBMAH is often regulated by various G protein-coupled receptors (GPCRs) aberrantly expressed in PBMAH tissues; some receptor ligands are ectopically produced in PBMAH tissues, creating aberrant autocrine/paracrine regulation of steroidogenesis. The bilateral nature of PBMAH and familial aggregation led to the identification of germline heterozygous inactivating mutations of the ARMC5 gene, in 20% to 25% of the apparent sporadic cases and more frequently in familial cases; ARMC5 mutations/pathogenic variants can be associated with meningiomas. More recently, combined germline mutations/pathogenic variants and somatic events inactivating the KDM1A gene were specifically identified in patients affected by glucose-dependent insulinotropic peptide (GIP)-dependent PBMAH. Functional studies demonstrated that inactivation of KDM1A leads to GIP-receptor (GIPR) overexpression and over- or downregulation of other GPCRs. Genetic analysis is now available for early detection of family members of index cases with PBMAH carrying identified germline pathogenic variants. Detailed biochemical, imaging, and comorbidity assessment of the nature and severity of PBMAH is essential for its management. Treatment is reserved for patients with overt or mild cortisol/aldosterone or other steroid excesses, taking in account comorbidities. It previously relied on bilateral adrenalectomy; however, recent studies tend to favor unilateral adrenalectomy or, less frequently, medical treatment with cortisol synthesis inhibitors or specific blockers of aberrant GPCR.

Bertherat J ，Bourdeau I ，Bouys L ，Chasseloup F ，Kamenický P ，Lacroix A ... -  《-》

Primary unilateral macronodular adrenal hyperplasia with concomitant glucocorticoid and androgen excess and KDM1A inactivation.

Primary bilateral macronodular adrenal hyperplasia (PBMAH) is a rare cause of Cushing's syndrome. Individuals with PBMAH and glucose-dependent insulinotropic polypeptide (GIP)-dependent Cushing's syndrome due to ectopic expression of the GIP receptor (GIPR) typically harbor inactivating KDM1A sequence variants. Primary unilateral macronodular adrenal hyperplasia (PUMAH) with concomitant glucocorticoid and androgen excess has never been encountered or studied. We investigated a woman with a large, heterogeneous adrenal mass and severe adrenocorticotropic hormone-independent glucocorticoid and androgen excess, a biochemical presentation typically suggestive of adrenocortical carcinoma. The patient presented during pregnancy (22nd week of gestation) and reported an 18-month history of oligomenorrhea, hirsutism, and weight gain. We undertook an exploratory study with detailed histopathological and genetic analysis of the resected adrenal mass and leukocyte DNA collected from the patient and her parents. Histopathology revealed benign macronodular adrenal hyperplasia. Imaging showed a persistently normal contralateral adrenal gland. Whole-exome sequencing of 4 representative nodules detected KDM1A germline variants, benign NM_001009999.3:c.136G > A:p.G46S, and likely pathogenic NM_001009999.3:exon6:c.865_866del:p.R289Dfs*7. Copy number variation analysis demonstrated an additional somatic loss of the KDM1A wild-type allele on chromosome 1p36.12 in all nodules. RNA sequencing of a representative nodule showed low/absent KDM1A expression and increased GIPR expression compared with 52 unilateral sporadic adenomas and 4 normal adrenal glands. Luteinizing hormone/chorionic gonadotropin receptor expression was normal. Sanger sequencing confirmed heterozygous KDM1A variants in both parents (father: p.R289Dfs*7 and mother: p.G46S) who showed no clinical features suggestive of glucocorticoid or androgen excess. We investigated the first PUMAH associated with severe Cushing's syndrome and concomitant androgen excess, suggesting pathogenic mechanisms involving KDM1A.

Elhassan YS ，Appenzeller S ，Landwehr LS ，Lippert J ，Popat D ，Gilligan LC ，Abdi L ，Goh E ，Diaz-Cano S ，Kircher S ，Gramlich S ，Sutcliffe RP ，Thangaratinam S ，Chan LF ，Fassnacht M ，Arlt W ，Ronchi CL ... -  《-》

Adrenal GIPR expression and chromosome 19q13 microduplications in GIP-dependent Cushing's syndrome.

Lecoq AL ，Stratakis CA ，Viengchareun S ，Chaligné R ，Tosca L ，Deméocq V ，Hage M ，Berthon A ，Faucz FR ，Hanna P ，Boyer HG ，Servant N ，Salenave S ，Tachdjian G ，Adam C ，Benhamo V ，Clauser E ，Guiochon-Mantel A ，Young J ，Lombès M ，Bourdeau I ，Maiter D ，Tabarin A ，Bertherat J ，Lefebvre H ，de Herder W ，Louiset E ，Lacroix A ，Chanson P ，Bouligand J ，Kamenický P ... -  《-》