Endocrine Abstracts

Currently, no effective medical therapy exists for inoperable phaeochromocytomas (PCCs). Thus, we investigated the antitumor potential of the dual PI3K/mTOR inhibitor NVP-BEZ235 against PCC in vivo. We employed a spontaneous model of endogenous aggressive PCCs (MENX rats), which closely recapitulate the human tumours. Administration of NVP-BEZ235 to MENX rats for 14 days inhibited proliferation (assessed by Ki67, NuSAP staining), vascularity (CD31, VEGFA), and induced...

Poor hormonal and tumour responses to somatostatin analogues (SSA) in acromegaly can occur although the aetiology is often unclear. Two genetic syndromes are associated with relative SSA resistance: acromegaly due to AIP mutations (AIPmut) and the newly described X-linked acrogigantism (X-LAG) syndrome due to chromosome Xq26.3 microduplications. We studied whether SSA resistance in these conditions was related to somatostatin receptor (SSTR) levels in tumour tissues. We studie...

Phaeochromocytomas (PCs) are neuroendocrine tumors derived from neural crest-derived chromaffin cells of the adrenal medulla and sympathetic ganglia.About 10% of all PCs can be malignant.Currently, there is no effective therapy for malignant PCs.In many neuroendocrine tumors, including PCs, the PI3K/AKT/mTOR survival pathway is hyperactivated. Therefore, the inhibition of this signaling cascade may exert an a...

Phaeochromocytomas (PCs) are neuroendocrine tumors derived from neural crest-derived chromaffin cells of the adrenal medulla and sympathetic ganglia (the latter referred to as paragangliomas), which produce significant amounts of catecholamines. Although PCs are mostly benign, 10% of all PCs can be malignant evidenced by the presence of metastases, predominantly in bone, lungs, liver and lymph. Currently, there is no effective therapy for malignant PCs.I...

Introduction: Somatostatin analogs (SSAs) are the first-line clinical treatment for patients with pituitary adenomas (PAs) but their efficacy is highly variable among patients. This could be due to a differential expression of somatostatin receptor subtypes (Ssts) among tumors, but this issue is still unresolved. Nonfunctioning pituitary adenomas (NFPAs), which mostly derive from gonadotroph cells, are among the tumors that poorly respond to SSAs. Rats carrying a germline loss...

Abstract: Somatostatin analogs (SSAs) constitute first-line treatment for patients with neuroendocrine tumors. Somatostatin receptors (SSTRs) are the most common therapeutic, radiotherapeutic, and imaging targets of SSAs. Some G-protein-coupled receptors, including SSTRs, regulate their responsiveness to continuous drug exposure with different degrees of receptor internalization. Thus, SSTR internalization seems to play an important role in predicting the response to SSAs in p...

Primary hyperparathyroidism (PHPT) is usually a sporadic disorder, but in <10% of cases occurs as part of hereditary syndromes, including multiple endocrine neoplasia types 1 and 2A (MEN1 and MEN2A), hyperparathyroidism-jaw tumor syndrome (HPT-JT) and familial isolated hyperparathyroidism (FIHP).MEN 1 is an autosomal dominant disorder characterized by tumours in multiple endocrine glands, most commonly parathyroid, enteropancreatic and anterior pitui...