ABSTRACT: Acromegaly is a severe and life-threatening disease caused by persistent excess of growth hormone (GH) which stimulates the synthesis and secretion of insulin-like growth factor-1 (IGF-1). In the majority (95%) of patients acromegaly is caused by sporadic GH-secreting neuroendocrine pituitary tumor (PitNET). Acromegaly-causing tumors are histologically diverse. The aim was to determine transcriptomic profiles in different histological subtypes and evaluate clinical implication of differential gene expression.
Project description:Objective Circulating plasma miRNAs have been increasingly studied in the field of pituitary neuroendocrine tumor (PitNET) research. Our aim was to discover circulating plasma miRNAs species associated with growth hormone (GH) secreting PitNETs and assess how the plasma levels of discovered miRNA candidates are impacted by SSA therapy and whether there is a difference in their levels between GH secreting PitNETs and other PitNET types. Methods miRNA candidates were discovered using the whole miRNA sequencing approach and differential expression analysis. Selected miRNAs were then analyzed using real-time polymerase chain reaction (qPCR). Results Whole miRNA sequencing discovered a total of 19 differentially expressed miRNAs (DEMs) in GH secreting PitNET patients' plasma 24 hours after surgery and 19 DEMs between GH secreting PitNET patients’ plasma and non-functioning (NF) PitNET patients’ plasma. Seven miRNAs were selected for further testing of which miR-625-5p, miR-503-5p miR-181a-2-3p and miR-130b-3p showed a significant downregulation in plasma after 1 month of SSA treatment. miR-181a-5p and mir-625-5p were also found to be significantly downregulated in plasma of GH secreting PitNET patients vs. NF PitNET patients. Conclusions Our study suggests that expression of plasma miRNAs miR-625-5p, miR-503-5p miR-181a-2-3p and miR-130b-3p in GH secreting PitNETs is affected by SSA treatment. Additionally, miR-625-5p and miR-181a-5p can distinguish GH secreting PitNETs from other PitNET types warranting further research on these miRNAs for treatment efficacy.
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.
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: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.
Project description:Data from 12 fresh-frozen somatotropinomas and their corresponding blood samples. Details are given in Valimaki et al. Whole-genome sequencing of Growth Hormone (GH) -secreting Pituitary Adenoma. Provisionally accepted, 2015.
Project description:This study, using a growth hormone (GH)-deficient dwarf animal model and peripheral GH replacement, investigated the effects of circulating IGF-1 during adolescence on IGF-1 levels in the brain. Our results demonstrated that hippocampal IGF-1 protein concentrations during adolescence are highly regulated by circulating IGF-1, which were reduced by GH deficiency and restored by systematic GH replacement. In contrast, IGF-1 levels in the CSF were decreased by GH deficiency but not restored by GH replacement. Furthermore, analysis of gene expression using microarrays and RT-PCR indicated that circulating IGF-1 levels did not modify the transcription of IGF-1 or its receptor in the hippocampus but did regulate genes that are involved in microvascular structure and function, brain development, and synaptic plasticity, which potentially support brain structures involved in cognitive function during this important developmental period.
Project description:Pituitary tumors (PitNETs) tumorigenesis is still not completely understood. Few studies have integrated exome, methylome, and transcriptome analyses. Taking advantage of a comprehensive phenotypic characterized Brazilian cohort, which has heterogeneous ethnic origin, we combined methylome and transcriptome analysis of the three major subtypes of surgically resectable PitNETs. Here, we included RNA-seq and basal patient / tumor data of 65 PitNETs: GH-secreting (acromegaly,n = 15), ACTH-secreting (Cushing disease, n = 7), and Non-Functioning (n = 43 PitNETs).
Project description:This study, using a growth hormone (GH)-deficient dwarf animal model and peripheral GH replacement, investigated the effects of circulating IGF-1 during adolescence on IGF-1 levels in the brain. Our results demonstrated that hippocampal IGF-1 protein concentrations during adolescence are highly regulated by circulating IGF-1, which were reduced by GH deficiency and restored by systematic GH replacement. In contrast, IGF-1 levels in the CSF were decreased by GH deficiency but not restored by GH replacement. Furthermore, analysis of gene expression using microarrays and RT-PCR indicated that circulating IGF-1 levels did not modify the transcription of IGF-1 or its receptor in the hippocampus but did regulate genes that are involved in microvascular structure and function, brain development, and synaptic plasticity, which potentially support brain structures involved in cognitive function during this important developmental period. GH-deficient dwarf (dw/dw) and heterozygous (HZ) rats were identified at postnatal day 33-34. Starting from d35, dw/dw rats received subcutaneous injection of either 300µg GH (dw/dw+GH) or saline (dw/dw+sal) for 7d or 30d. HZ animals received saline for the same periods as controls. Animals (n=4/group for each time point) were sacrificed, the hippocampi were dissected, and total RNA were isolated for subsequent transcriptomic profiling.
Project description:Abnormal DNA methylation contributes to tumor progression and is emerging as a prognostic marker in several types of cancers. Pituitary tumors (PitNETs) tumorigenesis is still not completely understood. Few studies have integrated exome, methylome, and transcriptome analyses. Taking advantage of a comprehensive phenotypic characterized Brazilian cohort, which has heterogeneous ethnic origin, we combined methylome and transcriptome analysis of the three major subtypes of surgically resectable PitNETs (n = 77): GH-secreting (acromegaly, n = 18), ACTH-secreting (Cushing disease, n = 13), and non-functioning (n = 46) PitNETs. Here, we included methylome and basal patient / tumor data.
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.