Project description:The aim of this study was to perform comparative gene expression analysis of AIP mutation-positive, AIP mutation-negative familial and sporadic somatotroph tumours to discover the genes/pathways responsible for the aggressive phenotype. Gene expression analysis was performed on 25 pituitary samples (five normal pituitary, six AIPpos GH, three AIPneg GH, four sporadic GH, two AIPneg familial NFPA and five sporadic NFPA adenomas) using the Affymetrix human Gene Chip HG-U133 Plus 2.0 array.
Project description:Corticotropin (ACTH)-secreting pituitary adenomas give rise to a severe endocrinological disorder, i.e., Cushing’s disease, with multifaceted clinical presentation and treatment outcomes. Experimental studies suggested that disease variability is inherent to the pituitary tumor, thus pointing to the need for further studies into tumor biology. Aim of the present study was to evaluate transcriptome expression pattern in a large series of ACTH-secreting pituitary adenoma specimens, in order to identify molecular signatures of these tumors. Gene expression profiling of formalin-fixed paraffin-embedded specimens from 40 human ACTH-secreting pituitary adenomas revealed significant expression of genes involved in protein biosynthesis and ribosomal function, in keeping with neuroendocrine cell profile. Unsupervised cluster analysis identified three distinct gene profile clusters and several genes were uniquely overexpressed in a given cluster, accounting for different molecular signatures. Of note, gene expression profiles were associated with clinical features such as age and size of the tumor. Altogether, our study shows that corticotrope tumors are characterized by neuroendocrine gene expression profile and present subgroup-specific molecular features.
Project description:Colorectal cancer can be divided into four consensus molecular subtypes, which might associate with distinct precursor lesions. The aim of this study was to determine the subtype affiliation of two types of colorectal adenomas: tubular adenomas (TAs) and sessile serrated adenomas (SSAs) and to determine the activity of TGFβ signaling and the role of this cytokine in subtype affiliation. Adenoma samples were collected in the Academic Medical Center (AMC), Amsterdam, The Netherlands. Tubular adenomas (TAs) were obtained from familial adenomatous polyposis (FAP) patients and sessile serrated adenomas (SSAs) were collected from serrated polyposis syndrome (SPS) patients. Gene expression was analyzed for 7 sessile serrated adenomas (SSA) and 9 tubular adenomas (TA).
Project description:Pituitary adenomas are benign tumors originating from the endocrine cells of the pituitary gland, but some pathological subtypes are highly invasive, known as invasive pituitary adenomas. Invasive pituitary adenomas are relatively rare, progress rapidly, easily invade surrounding tissues, have a high risk of recurrence, and have poor response to standard treatments. This study collected tumor specimens from 17 patients with non-invasive pituitary adenomas (FSH type) and 15 patients with invasive pituitary adenomas (ACTH-silent type), and performed transcriptome sequencing, aiming to explore the genetic differences between invasive and non-invasive pituitary adenomas.
Project description:Colorectal cancer can be divided into four consensus molecular subtypes, which might associate with distinct precursor lesions. The aim of this study was to determine the subtype affiliation of two types of colorectal adenomas: tubular adenomas (TAs) and sessile serrated adenomas (SSAs) and to determine the activity of TGFβ signaling and the role of this cytokine in subtype affiliation. Adenoma samples were collected in the Academic Medical Center (AMC), Amsterdam, The Netherlands. Tubular adenomas (TAs) were obtained from familial adenomatous polyposis (FAP) patients and sessile serrated adenomas (SSAs) were collected from serrated polyposis syndrome (SPS) patients.
Project description:Pituitary adenomas (PAs) are intracranial tumors associated with significant morbidity due to hormonal dysregulation, mass effects and heavy treatment burden. Growth hormone (GH)-secreting PAs (somatotropinomas) cause acromegaly-gigantism. Genetic forms of somatotropinomas due to germline AIP mutations (AIPmut+) have an early onset and are aggressive and resistant to treatment with somatostatin analogs (SSAs), including octreotide. The molecular underpinnings of these clinical features remain unclear. We investigate the role of miRNA dysregulation in AIPmut+ versus AIPmut- PA samples by array analysis. miR-34a and miR-145 were found highly expressed in AIPmut+ vs AIPmut-somatotropinomas. Ectopic expression of AIPmut (p.R271W) in Aip-/- mouse embryonic fibroblasts upregulated miR-34a and miR-145, establishing a causal link between AIPmut and miRNA expression. In PA cells (GH3), miR-34a overexpression promoted proliferation, clonogenicity, migration and suppressed apoptosis, whereas miR-145 moderately affected proliferation and apoptosis. Moreover, high miR-34a expression increased intracellular cAMP, a critical mitogenic factor in PAs. Crucially, high miR-34a expression significantly blunted octreotide-mediated GH inhibition and anti-proliferative effects. miR-34a directly targets Gnai2 encoding Gαi2, a G protein subunit inhibiting cAMP production. Accordingly, Gαi2 levels were significantly lower in AIPmut+ versus AIPmut- PA. Taken together, somatotropinomas with AIP mutations overexpress miR-34a, which in turn downregulates Gαi2 expression, increases cAMP concentration and ultimately promotes cell growth. Upregulation of miR-34a also impairs the hormonal and antiproliferative response of PA cells to octreotide. Thus, miR-34a is a downstream target of mutant AIP that promotes a cellular phenotype mirroring the aggressive clinical features of AIPmut+ acromegaly.
Project description:Gonadotroph adenomas comprise 15M-bM-^@M-^S40 % of all pituitary tumors, are usually non-functioning and are often large and invasive at presentation. Surgery is the first-choice treatment, but complete resection is not always achieved, leading to high recurrence rates. As gonadotroph adenomas poorly respond to conventional pharmacological therapies, novel treatment strategies are needed. Their identification has been hampered by our incomplete understanding of the molecular pathogenesis of these tumors. Recently, we demM-BM-,onstrated that MENX-affected rats develop gonadotroph adenomas closely resembling their human counterparts. To discover new genes/pathways involved in gonadotroph cells tumorigenesis, we performed transcriptome profiling of rat tumors versus normal pituitary. Adenomas showed overrepM-BM-,resentation of genes involved in cell cycle, development, cell differentiation/proliferation, and lipid metabolism. BioinforM-BM-,matic analysis identified downstream targets of the transcripM-BM-,tion factor SF-1 as being up-regulated in rat (and human) adenomas. Meta-analyses demonstrated remarkable similariM-BM-,ties between gonadotroph adenomas in rats and humans, and highlighted common dysregulated genes, several of which were not previously implicated in pituitary tumorigenesis. Two such genes, CYP11A1 and NUSAP1, were analyzed in 39 human gonadotroph adenomas by qRT-PCR and found to be up-regulated in 77 and 95 % of cases, respectively. Immunohistochemistry detected high P450scc (encoded by CYP11A1) and NuSAP expression in 18 human gonadoM-BM-,troph tumors. In vitro studies demonstrated for the first time that Cyp11a1 is a target of SF-1 in gonadotroph cells and promotes proliferation/survival of rat pituitary adenoma priM-BM-,mary cells and cell lines. Our studies reveal clues about the molecular mechanisms driving rat and human gonadotroph adenomas development, and may help identify previously unexplored biomarkers for clinical use. We compared five control animals and 16 homozygous mutants (p27Kip1/Cdknb1)
Project description:Gonadotroph adenomas comprise 15–40 % of all pituitary tumors, are usually non-functioning and are often large and invasive at presentation. Surgery is the first-choice treatment, but complete resection is not always achieved, leading to high recurrence rates. As gonadotroph adenomas poorly respond to conventional pharmacological therapies, novel treatment strategies are needed. Their identification has been hampered by our incomplete understanding of the molecular pathogenesis of these tumors. Recently, we dem¬onstrated that MENX-affected rats develop gonadotroph adenomas closely resembling their human counterparts. To discover new genes/pathways involved in gonadotroph cells tumorigenesis, we performed transcriptome profiling of rat tumors versus normal pituitary. Adenomas showed overrep¬resentation of genes involved in cell cycle, development, cell differentiation/proliferation, and lipid metabolism. Bioinfor¬matic analysis identified downstream targets of the transcrip¬tion factor SF-1 as being up-regulated in rat (and human) adenomas. Meta-analyses demonstrated remarkable similari¬ties between gonadotroph adenomas in rats and humans, and highlighted common dysregulated genes, several of which were not previously implicated in pituitary tumorigenesis. Two such genes, CYP11A1 and NUSAP1, were analyzed in 39 human gonadotroph adenomas by qRT-PCR and found to be up-regulated in 77 and 95 % of cases, respectively. Immunohistochemistry detected high P450scc (encoded by CYP11A1) and NuSAP expression in 18 human gonado¬troph tumors. In vitro studies demonstrated for the first time that Cyp11a1 is a target of SF-1 in gonadotroph cells and promotes proliferation/survival of rat pituitary adenoma pri¬mary cells and cell lines. Our studies reveal clues about the molecular mechanisms driving rat and human gonadotroph adenomas development, and may help identify previously unexplored biomarkers for clinical use.
Project description:In this work we employed the comprehensive evaluation of clinical data of the cohort of CD patients along with the sequencing of 14 exon of USP8 to estimate the prevalence of USP8 mutations in our cohort and transcriptome analysis of tumor tissue to search for the associations between USP8 mutation status, molecular markers of pituitary adenomas, and clinical and diagnostic parameters of Cushing’s syndrome including hormonal secretion, tumor size, aggressiveness, and SSRT2/SSRT5 expression.
Project description:Growth hormone-secreting pituitary adenomas account for approximately 10% of endocrine pituitary tumors and are pathologically classified into densely granulated adenomas (DGGH) and sparsely granulated adenomas (SGGH). m6A has been reported to play an important role in tumorigenesis and development, but its potential role in the pathogenesis of these two subtypes has not yet been thoroughly investigated. Consequently, we performed MeRIP-seq analysis of pituitary adenomas and the GH3 cell line. We observed that the expression of FTO was significantly increased in SGGH, leading to a reduction in m6A modification and a disruption of desmosome organization.