Endocrine Abstracts

Introduction: The silencing mechanisms of corticotroph tumors (CT) remain unclear. The most feasible hypothesis lies in a post-transcriptional deregulation of the POMC gene, precursor of ACTH. Micro RNAs (miRNAs) are small non-coding RNA molecules involved in the epigenetic regulation of gene expression through their inhibitory action on messenger RNA. miRNAs capable of inhibiting the expression of POMC have been described at the level of neurons of the hypot...

Introduction: Silent somatotroph tumors (sST) are a pituitary neuroendocrine tumor subtype with positive immunostaining for growth hormone (GH) but without the presence of acromegaly. Unlike silent corticotroph tumors, there is little information in the literature on sST. The aim of the present study was to study the demographic, clinical and molecular characteristics in a series of ST in order to compare sST and functioning ST (fST).Methods: We have stu...

Background: There is an increasing interest to find specific prognostic markers of the aggressive behaviour of some pituitary adenomas (PA). The most studied markers have been the immunohistochemical staining for Ki-67 and p53. The aim of this study was to evaluate the relevance as possible prognostic markers of growth factors (IGF1R), angiogenic factors (VEGF and his receptor) and new genes (PTTG) versus the immunohistochemical expression of Ki-67 and p53 in PA.<p class="...

Introduction: The last World Health Organization (WHO) 2016 classification of Pituitary Tumours recommends the determination of transcription factors. During the last few years, silent variants of the main pituitary tumours (PTs) have been described. The mechanisms of silencing of these tumors are still unknown. POU1F1 (Pit1) encodes a member of the POU family of transcription factors that has a relevant role in the differentiation, proliferation and survival of three...

Introduction: Because of the increase of brain image explorations, the prevalence of pituitary tumours has increased a lot. Although most of them have an indolent behaviour, some behave aggressively, demanding a lot of resources for their management. Therefore, it is very important to identify them as soon as possible. The recent WHO 2017 classification of pituitary tumours gives insights into improving their identification using the immunostaining (IS) of transcription factor...

Introduction: Recently we have demonstrated the contribution of the quantification of expression of adenohypophyseal hormone genes in the identification of the different Pituitary Neuroendocrine Tumor (PitNET) subtypes according to the 2004 WHO criteria.Aim: The aim of the present study was to evaluate the contribution of the quantification of expression of pituitary transcription factor genes to the identification of PitNETs according to 2017 WHO criter...

Context: The determination of human chorionic gonadotropin (hCG) in cerebrospinal fluid (CSF) is useful for the differential diagnosis of suprasellar lesions. However, the concentrations that prove diagnostic for neurohypophyseal germinoma have not been well defined. In addition, the immunoassays used for such determination are the same as those applied in serum, and few studies have been performed regarding the validation of such techniques in CSF.Objec...

Introduction: E2F1 regulates the expression of genes required for cell cycle progression and apoptosis. miR-17-5p regulates expression of E2F1. Both miR-17-5p and E2F1 have been described deregulated in cancer but they have been scarcely studied in human pituitary neuroendocrine tumours (PitNETs).The aim of the present study was to find biomarkers of aggressiveness in PitNETs and report the correlation between E2F1 and...

Introduction: The immunohistochemical characterization of Pit-1, Tpit and SF-1 transcription factors allows the identification of the three adenohypophyseal cell lines and has been incorporated into the latest WHO classification of pituitary adenomas (PA). The aim of the present study was to quantify the protein expression of pituitary-specific transcription factors (TF) by immunohistochemistry (IHC) and to correlate these results with the identification based on hormonal prot...

Introduction: Gonadotroph tumours (GT) are the most common subtype of silent pituitary neuroendocrine tumours. The diagnosis of this subtype of tumours is established after surgery. There are no reliable markers of aggressiveness to predict their clinical course and, moreover, immunohistochemistry (IHC) usually classifies GT as null cell tumours. The aim of the present study was to correlate molecular, immunohistochemical and biochemical gonadotropin expression, to quantify th...