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: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:Recurrent single-nucleotide and small indel somatic mutations were infrequent among the three adenoma subtypes. However, somatic copy-number alterations (SCNA) were identified in all three pituitary adenoma subtypes. Methylation analysis revealed adenoma subtype-specific DNA methylation profiles, with GHsecreting adenomas being dominated by hypomethylated sites. Likewise, gene-expression patterns revealed adenoma subtype-specific profiles. Integrating DNA methylation and gene-expression data revealed that hypomethylation of promoter regions are related with increased expression of GH1 and SSTR5 genes in GH-secreting adenomas and POMC gene in ACTH secreting adenomas. Finally, multispectral IHC staining of immune-related proteins showed abundant expression of PD-L1 among all three adenoma subtypes.
Project description:The aim of the study was to compare genes’ expression profiles of functioning and silent corticotroph adenomas to investigate possible biological mechanism of different hormone secretion . Since USP8 is the best know driver gene mutated in large proportion of ACTH-omas we intended to verify whether the mutation occurs in SCAs and how it affects transcriptomic profile.
Project description:Background Micro RNAs (miRNAs) are a class of small non-coding RNAs that are involved in post transcriptional gene expression regulation. miRNAS can be found in various bodily fluids including plasma. Recently circulating plasma miRNAs have been studied as biomarkers in various tumors including pituitary neuroendocrine tumors (PitNETs). However the identification of PitNET derived miRNAs in plasma remains a challenging task due to tumor volume, mass and miRNA dilution within blood. To our knowledge this is the first study that has used the NGS approach to characterize circulating miRNAs in plasma acquired from Bilateral petrosal sinus sampling (BIPSS) - a gold standard in diagnosis of ACTH secreting PitNETs. Results We sequenced plasma samples that were acquired from sinistral and dextral sides of sinus petrosus inferior and complementary plasma from peripheral venous blood (PVB). BIPSS samples were collected in three separate time periods: before administration of corticotropin releasing hormone (CRH), 5 minutes after stimulation and 15 minutes after stimulation with CRH. The highest amount of differentially expressed miRNAs was observed 5 minutes after CRH stimulation (20 upregulated, 14 downregulated). During the BIPSS procedure the highest amount of ACTH was released in the sinistral side during the 5th minute after the stimulation by CRH. In the plasma of sinistral side at the 5th minute we identified two miRNAs: hsa-miR-7-5p and hsa-miR-375-3p that were highly upregulated compared to other BIPSS samples and samples from PVB. Using clustering analysis we were able to distinguish plasma samples acquired from BIPSS from PVB plasma, indicating that the miRNA fraction characterized in this study has potentially PitNET borne origin. Conclusions In this study we provided the first insight into the landscape of circulating miRNAs in close proximity to the ACTH secreting PitNET. The data indicates that ACTH secreting PitNET releases two circulating miRNAs upon stimulation with CRH (hsa-mir-7-5p, hsa-mir-375-3p) alongside with ACTH implying the further studies of these miRNA as diagnostic markers.
Project description:Despite a considerable literature concerning the molecular pathogenesis of pituitary tumors, the mechanisms of pituitary tumors development and progression remain unknown. Four SAGE cDNA libraries were constructed using a pool of mRNA obtained from five GH-, two ACTH-secreting, and four non secreting pituitary tumors (NS), and three normal pituitaries from patients who had accidental death, using I-SAGE kit (Invitrogen). The aim of this study was to evaluate the differential gene expression profile by SAGE genes in different subtypes of pituitary tumors to contribute for understanding of pituitary tumorigenesis. Comparative analysis of gene expression profiles in subtypes of pituitary tumores.
Project description:The reasons why some pituitary adenomas are fucntioning(secreting hormones) or not is not well understood. This analysis dig into the transcriptomes of secreting and non-secreting corticotropic adenomas as well as non-fucntioning gonadotropic adenomas.
Project description:Sixty-nine (69) tumor samples were collected from patients who underwent thyroidectomy.<br><br>The tumors included 22 benign follicular adenomas, 18 follicular carcinomas, 12 samples of microfollicular adenomas, 4 anaplastic carcinomas, 2 papillary carcinomas, and 9 nodular goiters. 23 samples were obtained from the expression profile repository, Array Express, these counted 14 papillary carcinomas and 9 normal thyroid.
Project description:We profiled the somatic landscape of 21 growth hormone (GH) -secreting pituitary adenomas using somatic copy-number alteration (SCNA), whole-genome sequencing (WGS), bisulfate sequencing, and transcriptome approaches. See details in Valimaki et al. Genetic and epigenetic characterization of growth hormone (GH) - secreting pituitary tumors. Manuscript in preparation, 2019.