[Show abstract][Hide abstract] ABSTRACT: Patients with Xq26.3 microduplication present with X-linked acrogigantism (X-LAG) syndrome, an early-childhood form of gigantism due to marked growth hormone (GH) hypersecretion from mixed GH-PRL adenomas and hyperplasia. The microduplication includes GPR101, which is upregulated in patients' tumor tissue. The GPR101 gene codes for an orphan G protein coupled receptor that is normally highly expressed in the hypothalamus. Our aim was to determine whether GPR101 loss of function mutations or deletions could be involved in patients with congenital isolated GH deficiency (GHD). Taking advantage of the cohort of patients from the GENHYPOPIT network, we studied 41 patients with unexplained isolated GHD. All patients had Sanger sequencing of the GPR101 gene and array comparative genome hybridization (aCGH) to look for deletions. Functional studies (cell culture with GH secretion measurements, cAMP response) were performed. One novel GPR101 variant, c.589 G>T (p.V197L), was seen in the heterozygous state in a patient with isolated GHD. In silico analysis suggested that this variant could be deleterious. Functional studies did not show any significant difference in comparison with wild type for GH secretion and cAMP response. No truncating, frameshift, or small insertion-deletion (indel) GPR101 mutations were seen in the 41 patients. No deletion or other copy number variation at chromosome Xq26.3 was found on aCGH. We found a novel GPR101 variant of unknown significance, in a patient with isolated GH deficiency. Our study did not identify GPR101 abnormalities as a frequent cause of GH deficiency.
No preview · Article · Jan 2016 · Hormone and Metabolic Research
[Show abstract][Hide abstract] ABSTRACT: Over the last 5 years, new actors involved in the pathogenesis of combined pituitary hormone deficiency in humans have been reported: they include a member of the immunoglobulin superfamily glycoprotein and ciliary G protein coupled receptors, as well as new transcription factors and signalling molecules. New modes of inheritance for alterations of genes encoding transcription factors have also been described. Finally, actors known to be involved in a very specific phenotype (hypogonadotroph hypogonadism for instance) have been identified in a wider range of phenotypes. These data thus suggest that new mechanisms could explain the low rate of etiological identification in this heterogeneous group of diseases. Taking into account the fact that several reviews have been published in recent years on classical aetiologies of CPHD such as mutations of POU1F1 or PROP1, we focused the present overview on the data published in the last 5 years, to provide the reader with an updated review on this rapidly evolving field of knowledge.
Preview · Article · Jan 2016 · European Journal of Endocrinology
[Show abstract][Hide abstract] ABSTRACT: Context:
Cushing's disease (CD) is due to pituitary corticotrope adenomas that produce unrestrained ACTH secretion and have lost the negative feedback exerted by glucocorticoids (Gc). Gc also restrain corticotrope proliferation and the mechanisms of this inhibition are poorly understood.
The aim of the study was to identify cell cycle regulatory genes that are regulated by Gc and the Glucocorticoid Receptor (GR), and to assess regulatory genes that have a rate-limiting action on corticotrope prolifera tion and may be disregulated in CD.
The mouse corticotrope tumor cells AtT-20 were used to identify Gc-regulated genes that contribute to control of cell cycle progression. Surgery sections from CD patients were used to assess expression of CABLES1 in corticotrope adenomas.
Gene expression profiling, siRNA knockdowns, cell cycle analyses and genetic manipulations were carried out in AtT-20 cells. ChIPseq for pituitary-restricted transcription factors and RNA PolymeraseII was used to identify regulatory elements and genes that bind GR and are direct transcriptional targets. A panel of previously well-characterized corticotrope adenomas was used to correlate expression of CABLES1 with other markers.
Gc altered expression of three positive and three negative regulators of cell cycle progression. Two Myc genes (L-Myc, N-Myc) and E2F2 are repressed by Gc whereas genes for the negative regulators of cell cycle Gadd45β, Gadd45γ and Cables1 are actived by Gc. Cables1 siRNA knockdown strongly stimulates AtT-20 cell proliferation and antagonizes the growth inhibition produced by Gc. The Gadd45 and Cables1 genes have the hallmarks of direct Gc targets. CABLES1 is expressed in normal human pituitary cells but expression is lost in ∾55% corticotrope adenomas and this is strongly correlated with the loss of p27(Kip1) expression.
CABLES1 is a critical regulator of corticotrope proliferation that defines a pathway often inactivated in CD and links proliferation to Gc resistance.
No preview · Article · Dec 2015 · Journal of Clinical Endocrinology & Metabolism
[Show abstract][Hide abstract] ABSTRACT: Objective:
To monitor long-term pegvisomant treatment of patients with acromegaly in routine clinical practice.
Patients and methods:
The French ACROSTUDY is part of the global ACROSTUDY, an observational post-authorization safety surveillance study of acromegaly treatment with pegvisomant.
The median duration of follow-up of the 292 included patients was 5.2 years. Overall 272 (93%) patients received somatostatin analogues before initiation of pegvisomant. The most prescribed initial dose of pegvisomant (after possible administration of a loading dose) was 10mg/day and, starting from the 2nd year, the median dose was 20mg/day. Serum IGF-1 concentration decreased as soon as pegvisomant was started and after 5 years there was a 62% mean decrease in serum IGF-1 concentration. The percentage of patients with serum IGF-1 concentration within normal ranges (for age and sex) of the local laboratory shifted from 11% at start of pegvisomant to 43% at 6 months and 63% after 5 years. The last available imaging (242 patients) showed an increased or decreased tumor size in 4 and 10% of patients, respectively. Mean weight increased by 3kg over the 5-year period (P<10(-3)). Mean fasting blood glucose significantly decreased over time (P<0.05), while HbA1c level remained unchanged. Tolerance profile was generally good and similar to that described in clinical studies.
This analysis showed a significant decrease in IGF-1 levels throughout the follow-up period, and confirmed that pegvisomant treatment is safe in acromegaly. The results of this interim analysis remain to be confirmed by the final analysis.
No preview · Article · Nov 2015 · Annales d Endocrinologie
[Show abstract][Hide abstract] ABSTRACT: The management of hereditary pheochromocytoma has drastically evolved in the last 20 years. Bilateral pheochromocytoma does not increase mortality in multiple endocrine neoplasia type 2 (MEN 2) or von Hippel-Lindau (VHL) mutation carriers who are followed regularly, but these mutations induce major morbidities if total bilateral adrenalectomy is performed. Cortical sparing adrenal surgery may be proposed to avoid definitive adrenal insufficiency. The surgical goal is to leave sufficient cortical tissue to avoid glucocorticoid replacement therapy. This approach was achieved by the progressive experience of minimally invasive surgery via the transperitoneal or retroperitoneal route. Cortical sparing adrenal surgery exhibits less than 5% significant recurrence after 10 years of follow-up and normal glucocorticoid function in more than 50% of cases. Therefore, cortical sparing adrenal surgery should be systematically considered in the management of all patients with MEN 2 or VHL hereditary pheochromocytoma. Hereditary pheochromocytoma is a rare disease, and a randomized trial comparing cortical sparing vs. classical adrenalectomy is probably not possible. This lack of data most likely explains why cortical sparing surgery has not been adopted in most expert centers that perform at least 20 procedures per year for the treatment of this disease. This review examined recent data to provide insight into the technique, its indications, and results and subsequent follow-up in the management of patients with hereditary pheochromocytoma with a special emphasis on MEN 2.
No preview · Article · Aug 2015 · European Journal of Endocrinology
[Show abstract][Hide abstract] ABSTRACT: ISL1 is a LIM homeodomain transcription factor necessary for development of the pituitary, retina, motor neurons, heart, and pancreas. Isl1 deficient mice (Isl1(-/-)) die early during embryogenesis at embryonic day 10.5 due to heart defects, and at that time, they have an undersized pituitary primordium. ISL1 is expressed in differentiating pituitary cells in early embryogenesis. Here we report the cell specific expression of ISL1 and assessment of its role in gonadotropes and thyrotropes. Isl1 expression is elevated in pituitaries of Cga(-/-) mice, a model of hypothyroidism with thyrotrope hypertrophy and hyperplasia. Thyrotrope-specific disruption of Isl1 with Tshb-cre is permissive for normal serum TSH, but T4 levels are decreased suggesting decreased thyrotrope function. Inducing hypothyroidism in normal mice causes a reduction in T4 levels and dramatically elevated TSH response, but mice with thyrotrope-specific disruption of Isl1 have a blunted TSH response. In contrast, deletion of Isl1 in gonadotropes with an Lhb-cre transgene has no obvious effect on gonadotrope function or fertility. These results show that ISL1 is necessary for maximal thyrotrope response to hypothyroidism, in addition to its role in development of Rathke's pouch.
No preview · Article · Aug 2015 · Molecular Endocrinology
[Show abstract][Hide abstract] ABSTRACT: Despite being a classical growth disorder, pituitary gigantism has not been studied previously in a standardized way. We performed a retrospective, multicenter, international study to characterize a large series of pituitary gigantism patients. We included 208 patients (163 males; 78.4%) with growth hormone excess and current/previous abnormal growth velocity for age or final height >2SD above country normal means. The median onset of rapid growth was 13.0 years and occurred significantly earlier in females than in males; pituitary adenomas were diagnosed earlier in females than males (15.8 vs. 21.5 years, respectively). Adenomas were ≥10 mm (i.e. macroadenomas) in 84%, of which extrasellar extension occurred in 77% and invasion in 54%. GH/IGF-1 control was achieved in 39% during long-term follow-up. Final height was greater in those with younger age of onset, with larger tumors and higher GH levels. Later disease control was associated with a greater difference from mid-parental height (r=0.23, P=0.02). AIP mutations occurred in 29%; microduplication at Xq26.3 -X-linked acro-gigantism (X-LAG)- occurred in two familial isolated pituitary adenoma (FIPA) kindreds and in ten sporadic patients. Tumor size was not different in X-LAG, AIP mutated and genetically-negative patient groups. AIP-mutated and X-LAG patients had significantly younger age at onset and diagnosis, but disease control was worse in genetically-negative cases. Pituitary gigantism patients are characterized by male predominance and large tumors that are difficult to control. Treatment delay increases final height and symptom burden. AIP mutations and X-LAG explain many cases, but no genetic etiology is seen in >50% of cases.
Full-text · Article · Jul 2015 · Endocrine Related Cancer
[Show abstract][Hide abstract] ABSTRACT: In couples presenting with retrograde ejaculation refractory to medical treatment, the first choice of fertility treatment should be Assisted Reproductive Techniques using rapidly purified spermatozoa retrieved from post-ejaculatory urine. The Hotchkiss technique and modified variants are simple and efficient for retrieving sperm from the bladder. We developed a new protocol, including a novel modified Hotchkiss technique involving sperm cryopreservation. The aim was to study the pregnancy rate and birth rate achieved by intra cytoplasmic sperm injection (ICSI) using frozen-thawed sperm retrieved from the bladder with this novel modified Hotchkiss technique in patients with refractory retrograde ejaculation.
In this descriptive retrospective, single-center study, we analyzed the local database of all patients who banked sperm at the CECOS Laboratory Biology of Reproduction of La Conception University Hospital, Marseille, France, between 2004 and 2014. A total of 2171 patients banked sperm during this time, including 63 patients with retrograde ejaculation, of whom ten patients banked sperm that had been retrieved by the modified Hotchkiss technique. These ten couples underwent 26 ICSI cycles: nine clinical pregnancies were achieved in six couples, including eight after fresh embryo transfer and one after thawed embryo transfer, resulting in seven live births. The average live birth rate per transfer was 28 %.
We report the largest series of births using frozen-thawed spermatozoa retrieved from post-ejaculatory urine by a modified Hotchkiss technique. This series of births demonstrates that this new modified Hotchkiss technique allows for successful association with sperm cryopreservation, leading to an efficient and easy management of couples with refractory retrograde ejaculation.