vasoactive-intestinal-peptide and Adrenal-Cortex-Neoplasms

Multiple Endocrine Neoplasia type 1 (MEN1) is a rare autosomal dominant hereditary cancer syndrome presented mostly by tumours of the parathyroids, endocrine pancreas and anterior pituitary, and characterised by a very high penetrance and an equal sex distribution. It occurs in approximately one in 30,000 individuals. Two different forms, sporadic and familial, have been described. The sporadic form presents with two of the three principal MEN1-related endocrine tumours (parathyroid adenomas, entero-pancreatic tumours and pituitary tumours) within a single patient, while the familial form consists of a MEN1 case with at least one first degree relative showing one of the endocrine characterising tumours. Other endocrine and non-endocrine lesions, such as adrenal cortical tumours, carcinoids of the bronchi, gastrointestinal tract and thymus, lipomas, angiofibromas, collagenomas have been described. The responsible gene, MEN1, maps on chromosome 11q13 and encodes a 610 aminoacid nuclear protein, menin, with no sequence homology to other known human proteins. MEN1 syndrome is caused by inactivating mutations of the MEN1 tumour suppressor gene. This gene is probably involved in the regulation of several cell functions such as DNA replication and repair and transcriptional machinery. The combination of clinical and genetic investigations, together with the improving of molecular genetics knowledge of the syndrome, helps in the clinical management of patients. Treatment consists of surgery and/or drug therapy, often in association with radiotherapy or chemotherapy. Currently, DNA testing allows the early identification of germline mutations in asymptomatic gene carriers, to whom routine surveillance (regular biochemical and/or radiological screenings to detect the development of MEN1-associated tumours and lesions) is recommended.

Topics: Adolescent; Adrenal Cortex Neoplasms; Adult; Aged; Aged, 80 and over; Angiofibroma; Carcinoid Tumor; Child; Facial Neoplasms; Female; Gastrinoma; Genetic Testing; Humans; Insulinoma; Lipoma; Male; Meningioma; Middle Aged; Multiple Endocrine Neoplasia Type 1; Pancreatic Neoplasms; Parathyroid Neoplasms; Pituitary Neoplasms; Prolactinoma; Proto-Oncogene Proteins; Thyroid Neoplasms; Vasoactive Intestinal Peptide; Young Adult

Adrenocortical carcinoma is an uncommon malignancy and feminizing symptoms secondary to adrenal estrogen-secretion are extremely rare. The direct secretion of estradiol by adrenocortical tumors requires, in addition to the expression of aromatase (CYP19), the expression of one or more of the reductive 17beta-hydroxysteroid dehydrogenases. The expression of CYP19 transcripts and protein were markedly induced in the H295 adrenocortical carcinoma cell line after treatment with either forskolin or vasoactive intestinal peptide (VIP). Western immunoblotting demonstrated a marked induction of the CYP19 protein of characteristic size after only a short (6h) treatment period with VIP or forskolin. The CYP19 mRNA transcripts were derived from both promoters PII (Ic) and I.3 (Id) after treatment with both agents. The reductive type 5 17beta-hydroxysteroid dehydrogenase (AKR1C3) was also constitutively expressed in the H295 cells but neither its mRNA transcript nor protein levels were altered after forskolin or VIP treatment. Western immunoblotting of an estrogen-secreting adrenal carcinoma revealed notable levels of both aromatase and AKR1C3 expression while an aldosterone-producing adrenal adenoma lacked aromatase expression and showed a reduced level of AKR1C3 expression. Immunohistochemistry of the carcinoma-bearing adrenal revealed localization of AKR1C3 not only in the tumor but also principally in the zona reticularis of the normal adrenal tissue. Adrenal aromatase and AKR1C3 expression therefore appear to be features of adrenocortical malignancies that are associated with biosynthesis of active estrogen.

Topics: 17-Hydroxysteroid Dehydrogenases; 3-Hydroxysteroid Dehydrogenases; Adrenal Cortex Neoplasms; Adult; Aldo-Keto Reductase Family 1 Member C3; Aromatase; Cell Line, Tumor; Colforsin; Cytochrome P-450 CYP11B2; Estrogens; Female; Humans; Hydroxyprostaglandin Dehydrogenases; Progesterone Reductase; Promoter Regions, Genetic; Steroid 11-beta-Hydroxylase; Steroid 17-alpha-Hydroxylase; Vasoactive Intestinal Peptide

The innervation of the human adrenal gland and of cortical lesions was studied in sections of cortical tissue (n=10), hyperplastic cortical tissue (n=3), and tissue from cortical adenomas (n=5) and carcinomas (n=6). The presence and distribution of nerve structures containing neuronal markers indicating sympathetic and parasympathetic innervation were studied by immunohistochemistry and the co-existence and co-localization patterns of the different markers by immunofluorescence. The cortex and hyperplastic cortical tissue had a moderate to rich supply of nerve structures containing the typical neuronal markers: protein gene product 9.5 (PGP 9.5), neuron-specific enolase (NSE), small vesicle synaptic protein type 2 (SV2), and nerves showing immunoreactivity to the adrenergic marker tyrosine hydroxylase (TH). All these immunoreactive nerves were located predominantly adjacent to blood vessels, but also among parenchymal cells. The cortex showed numerous nerve structures containing the neuropeptide substance P (SP), neuropeptide Y (NPY) and vasoactive intestinal protein (VIP), but few nerves containing these peptides were seen in hyperplastic cortical tissue. Typical markers were occasionally observed in cortical adenomas but were not found in carcinomas, except in a few cases where PGP 9.5 and NSE were present, but only adjacent to necrotic areas. Nerves containing NPY and VIP occurred in varying numbers in both adenomas and carcinomas. NPY- and VIP-immunoreactive nerve structures were seen mostly alongside blood vessels. There were several types of co-existence. For instance, NSE/VIP-, TH/VIP- and TH/NPY-immunoreactive nerve structures were often seen in the same trunk, but were only partly co-localized.

Topics: Adenoma; Adrenal Cortex; Adrenal Cortex Neoplasms; Carcinoma; Fluorescent Antibody Technique, Indirect; Humans; Hyperplasia; Immunoenzyme Techniques; Membrane Glycoproteins; Nerve Tissue Proteins; Neuropeptide Y; Parasympathetic Nervous System; Phosphopyruvate Hydratase; Sympathetic Nervous System; Thiolester Hydrolases; Tyrosine 3-Monooxygenase; Ubiquitin Thiolesterase; Vasoactive Intestinal Peptide

VIP receptors are frequently overexpressed by various endocrine tumors. In this study the expression of VIP receptors in the human adrenocortical carcinoma cell line NCI-H295 and their involvement in the regulation of steroidogenesis was investigated. NCI-H295 cells express VIP1 and VIP2 receptors as demonstrated by RT-PCR, whereas they do not express VIP itself. The receptors are functionally coupled to steroidogenesis since VIP (10(-9) M to 10(-6) M) exerted a dose-dependent stimulatory effect on the release of aldosterone, cortisol, and DHEA. VIP increased ACTH-stimulated releases of aldosterone and cortisol. The proliferation rate of NCI-H295 cells was not affected by VIP. These data show that NCI-H295 cells express both forms of the VIP receptor and that VIP is involved in an ACTH-independent regulation of steroidogenesis in the adrenal tumor cells.

Topics: Adrenal Cortex; Adrenal Cortex Hormones; Adrenal Cortex Neoplasms; Aldosterone; Dehydroepiandrosterone; Dose-Response Relationship, Drug; Humans; Hydrocortisone; Receptors, Vasoactive Intestinal Peptide; Tumor Cells, Cultured; Vasoactive Intestinal Peptide

The purpose of this study was to investigate the mechanisms of action of pituitary adenylate cyclase-activating polypeptide (PACAP) in stimulating aldosterone production in two different models: bovine adrenal zona glomerulosa (ZG) cells in primary culture and the human adrenocortical carcinoma cell line H295R. PACAP binds to two major groups of receptors: type I, which prefers PACAP38 and PACAP27 over vasoactive intestinal peptide (VIP); and type II, which has approximately equal affinity for PACAP38, PACAP27, and VIP. The type I subclass comprises multiple splice variants that can be distinguished by their specificity to PACAP38 and PACAP27 in their activation of adenylate cyclase and phospholipase C. Type II PACAP/ VIP receptors couple only to AC. In bovine ZG cells, PACAP38 and PACAP27 stimulated aldosterone production in a dose-dependent manner, whereas VIP was ineffective. In H295R cells, PACAP38, PACAP27, and VIP dose-dependently stimulated aldosterone production with roughly the same ED50. In bovine ZG cells, PACAP38 and PACAP27 stimulated cAMP production with similar efficacy, whereas VIP had no effect. In H295R cells, all three peptides stimulated cAMP accumulation. PACAP38 and PACAP27 also activated PLC in bovine ZG cells as they induced an increase in Ins(1,4,5)Ps production. In H295R cells, neither of these peptides was able to stimulate IP turnover. These results indicate that PACAP stimulation of aldosterone production is mediated by the PVR1s or the PVR1hop splice variants of the type I PACAP-specific receptor subtype in bovine ZG cells, whereas only type II PACAP/VIP receptors seemed to occur in the human H295R cell line. In addition, PACAP-stimulated aldosterone production was inhibited by atrial natriuretic peptide in bovine and human adrenocortical cells, however not by the same mechanism. This further supports species-specific and/or cell type-specific signaling pathways for PACAP in the regulation of aldosterone production.

Topics: Adrenal Cortex Neoplasms; Aldosterone; Animals; Atrial Natriuretic Factor; Cattle; Cells, Cultured; Cyclic AMP; Humans; Inositol 1,4,5-Trisphosphate; Neuropeptides; Pituitary Adenylate Cyclase-Activating Polypeptide; Vasoactive Intestinal Peptide; Zona Glomerulosa

To investigate a possible direct action of vasoactive intestinal polypeptide (VIP) on adrenal cortisol secretion and to define its mechanism of action.. The human adrenocortical carcinoma cell line NCI H295, which is not contaminated by medullary chromaffin cells, was used to aid distinction between a direct action of VIP on adrenocortical cells and an indirect mechanism involving VIP-stimulated release of catecholamines.. NCI H295 cells were challenged with 10(-11)-10(-7) mol/l VIP for 4 h, with or without prior exposure for 72 h to 10 micromol/l forskolin. Cortisol and cyclic AMP contents of the overlying media were measured using in-house radioimmunoassays. Cells were treated with 10(-8)-10(-6) mol/l adrenaline or 3.3 x 10(-8) mol/l VIP with and without 10(-8)-10(-6) mol/l propranolol to exclude the possibility that an indirect mechanism of action involving beta-adrenoceptors was operating.. VIP treatment produced an increase in cortisol secretion without pre-incubation, but this was markedly enhanced by prior exposure of cells to forskolin. VIP was potent, with a threshold of 10(-11) mol/l (n = 4), reaching a maximum 3.9+/-0.9-fold increase in effect on cells pre-exposed to forskolin (n = 4) by 3.3 x 10(-8) mol/l. This increase matched the 4 h response to 10 micromol/l forskolin. Cortisol secretion was accompanied by a parallel, dose-dependent increase in accumulation of cAMP.. VIP potently and directly stimulates secretion of cortisol from these adrenocortical cells of human origin via an adenylate cyclase-coupled VIP receptor. These findings raise the possibility of a significant and direct effect of VIP in the control of steroid secretion from the adrenal cortex in humans.

Topics: Adrenal Cortex Neoplasms; Adrenergic beta-Antagonists; Adrenocortical Carcinoma; Colforsin; Cyclic AMP; Dose-Response Relationship, Drug; Humans; Hydrocortisone; Propranolol; Radioimmunoassay; Stimulation, Chemical; Tumor Cells, Cultured; Vasoactive Intestinal Peptide

Our patient had a left suprarenal mass. His blood pressure was normal, but his urinary catecholamines (CA), vanillylmandelic acid (VMA), total metanephrines (TMn) and 5-hydroxyindolacetic acid (5HIAA) were elevated. In addition, he had elevated, nonsuppressible urinary 17-ketosteroids (17KS) and androsterone, but his urinary 17-hydroxycorticoids (17OHCS) and free cortisol were normal, as were his plasma cortisol and ACTH. After resection of the suprarenal mass, the patient's urinary hormone values reverted to normal. The mass contained a pheochromocytoma and an adrenocortical adenoma. The pheochromocytoma was unusual in that it contained very little norepinephrine (NE) and dopamine (DA) and an abundance of epinephrine (E) despite normal enzyme concentrations. Electron micrographs showed primarily E granules with few of the NE-type. The immunoperoxidase histochemical stains for vasoactive intestinal peptide (VIP) and serotonin (S) were strongly positive. The patient's blood pressure may have been normal because his pheochromocytoma secreted E, VIP, or S. The associated adrenocortical adenoma produced no symptoms and was probably coincidental.

Topics: Adenoma; Adrenal Cortex Neoplasms; Androgens; Catecholamines; Gas Chromatography-Mass Spectrometry; Histocytochemistry; Humans; Immunoenzyme Techniques; Male; Microscopy, Electron; Middle Aged; Multiple Endocrine Neoplasia; Pheochromocytoma; Serotonin; Vasoactive Intestinal Peptide