Endocrine Abstracts

Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant disorder characterised by occurrence of parathyroid tumours and neuroendocrine tumours (NETs) of the pancreas and pituitary, which is caused by mutations of the MEN1 gene, encoding menin. Mouse models are important in elucidating mechanisms of MEN1 tumourigenesis and treatments, but the current models have limitations. Thus, in conventional heterozygous MEN1 knockout models, tumour d...

Epigenetic modifications and chromatin remodelling have been demonstrated to play a key role in the development, and progression of multiple cancers, and compounds regulating these mechanisms represent a novel class of anti-cancer drugs. Menin, which is encoded by the MEN1 gene, whose mutations result in a syndrome characterised by pituitary, parathyroid and pancreatic islet tumours, binds histone modifying enzymes, including the histone methyltransferase MLL1. Furthe...

There are currently no curative treatments for metastatic pancreatic neuroendocrine tumours (PNETs), and the 5-year survival is <50%. Such tumours frequently have mutations in chromatin remodelling genes as well as the protein encoded by the multiple endocrine neoplasia type 1 (MEN1) gene, menin, which is mutated in up to 40% of sporadic PNETs, and binds the histone methyltransferase MLL1. Histone modifications, and specifically acetylated residues on histone tail...

Marshall-Smith syndrome (MSS) is a congenital disorder affecting skeletal and neural development due to mutations in the nuclear factor I/X (NFIX) gene. Of these mutations, 61% are small insertions/deletions, 12% are splice site mutations and 27% are large exonic deletions clustered in exons 6–10 of the NFIX gene. In order to derive a MSS mouse model, the N-ethyl-N-nitrosourea (ENU) mutagenesis DNA archive was screened ...

Improved therapies for pancreatic and pituitary neuroendocrine tumors (NETs), which may occur in Multiple Endocrine Neoplasia type 1 (MEN1), are needed. We assessed the effects of pasireotide, a somatostatin analogue with high affinity for somatostatin receptors (SSTRs) −1, −2, −3 and −5, in a mouse model of MEN1. Men1+/− mice treated from 12 months of age with 40 μg/g pasireotide (n=71), or phosphate-buffered sal...

Case history: Vitamin D-dependent rickets type 2 (VDDR2) is an autosomal recessive condition caused by resistance to 1,25(OH)2D3, either through vitamin D receptor (VDR) mutations (type A) or abnormal expression of interfering proteins (type B), resulting in hypocalcaemia despite elevated plasma 1,25(OH)2D3 and parathyroid hormone concentrations. We report a proband, born to Caucasian non-consanguineous parents, who presente...

Heterozygous germline gain-of-function mutations of the extracellular calcium-sensing receptor (CaSR), a G-protein coupled receptor (GPCR), result in autosomal dominant hypocalcaemia type 1 (ADH1), which may cause symptomatic hypocalcaemia with low circulating parathyroid hormone (PTH) concentrations and hypercalciuria. Negative allosteric CaSR modulators, known as calcilytics, rectify the gain-of-function caused by CaSR mutations and are a potential targeted therapy for ADH1....

Familial hypocalciuric hypercalcaemia (FHH) comprises three genetic variants: FHH types 1 and 2 are due to mutations of the calcium-sensing receptor (CaSR) and G-protein subunit alpha-11, whereas, FHH type 3 (FHH3) is caused by heterozygous mutations affecting the Arg15 residue (Arg15Cys, Arg15His, Arg15Leu) of the adaptor-related protein complex 2-sigma subunit (AP2S1), which regulates CaSR endocytosis. FHH is usually associated with mild hypercalcaemia, normal parathyroid ho...

Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant disorder characterised by the occurrence of parathyroid, pancreatic and pituitary tumours, and is due to mutations of the MEN1 gene, which encodes menin. We have investigated identical twins with MEN1, one of whom developed primary hyperparathyroidism (PHPT) and a prolactinoma that caused pubertal arrest, and the other had PHPT only. DNA sequence analysis of the MEN1 coding region had not ide...

Pseudohypoparathyroidism (PHP) is due to parathyroid hormone (PTH) resistance that results in hypocalcaemia, hyperphosphataemia and elevated plasma PTH concentrations. Some PHP patients also have Albright’s hereditary dystrophy (AHO), which is characterised by short stature, round faces, dental hypoplasia, brachydactyly, subcutaneous ossifications and reduced mental acuity. The 3 major types of PHP referred to as PHP type 1a (PHP1a), PHP1b and pseudopseudohypoparathyroidi...