EPAS1-mutated paragangliomas are associated with hemoglobin disorders
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE249273 | GEO | 2023/12/11
REPOSITORIES: GEO
Similar Datasets
Project description:A Cartes d'Identité des Tumeurs (CIT) project from the french Ligue Nationale Contre le Cancer (http://cit.ligue-cancer.net) | Affymetrix HG-U133 Plus 2.0 : 188 tumor samples |Pheochromocytomas and paragangliomas are neuroendocrine tumors occuring in the context of inherited cancer syndromes in approximately 30% of cases, linked to germline mutations in VHL, RET, NF1, SDHA, SDHB, SDHC, SDHD, SDHAF2 or TMEM127 genes. Although progress has been made with regard to tumorigenesis mechanisms in pheochromocytoma/paraganglioma thanks to genome-wide expression studies, the question of a putative molecular distinction between VHL- and SDHx- on one hand, and RET- and NF1-related tumors on the other hand, remained to be addressed as well as the characterization of genetic events in sporadic tumors. With this purpose, 202 pheochromocytomas/paragangliomas, including 75 hereditary tumors, were investigated by expression profiling, array CGH and somatic mutation screening. The systematic characterization of somatic genetic events associated with tumor suppressor gene germline mutations in tumor tissues reveals a majority of loss of heterozygosity (LOH) but also point mutations and copy neutral LOH. Gene-expression signature defined the hereditary tumors according to their genotype. Especially, a complete sub-separation between SDHx- and VHL-related tumors was observed. Moreover, guided by the transcriptome classification and the LOH profile, somatic mutations in VHL or RET genes were identified in 14% of sporadic pheochromocytomas/paragangliomas. A genetic cause was found in 45.5% (92/202) of the large series of pheochromocytomas/paragangliomas analyzed. Regarding mutated genes, specific molecular pathways involved in tumorigenesis mechanisms are showed. Altogether, these new findings suggest that somatic mutation analysis would give important clues for personalized molecular target therapies.
2011-07-07 | E-MTAB-733 | biostudies-arrayexpress
Project description:The similarity in gene-expression profiles suggest that PGL2, like SDHD, is involved in the functionality of the SDH complex, and that tumor formation in these three subgroups involves the same pathways as in SDH linked paragangliomas. We were not able to clarify the identity of PGL2 on 11q13. The lack of differential gene-expression of chromosome 11 genes might indicate that chromosome 11 loss, as demonstrated in SDHD-linked paragangliomas, is an important feature in the formation of a paraganglioma regardless of the genetic background. Keywords: disease state analysis We compared the gene expression profiles of sporadic (n=7), SDHD- (n=6) and PGL2-linked (n=4) head and neck paraganglioma.
2008-12-10 | E-GEOD-12921 | biostudies-arrayexpress
Project description:The similarity in gene-expression profiles suggest that PGL2, like SDHD, is involved in the functionality of the SDH complex, and that tumor formation in these three subgroups involves the same pathways as in SDH linked paragangliomas. We were not able to clarify the identity of PGL2 on 11q13. The lack of differential gene-expression of chromosome 11 genes might indicate that chromosome 11 loss, as demonstrated in SDHD-linked paragangliomas, is an important feature in the formation of a paraganglioma regardless of the genetic background. Keywords: disease state analysis
2008-12-10 | GSE12921 | GEO
Project description:Gene-centric CNV analysis of 24 individual paraganglioma cases identified a list of 104 genes most significantly targeted by tumor-associated alterations. The NOTCH signaling pathway was the most significantly enriched term in the list. Overexpression of the relevant NOTCH pathway proteins in sustentacular (glial), chief (neuroendocrine) and endothelial cells was confirmed by immunomorphological studies in 47 paragangliomas, including CNV-tested cases. NOTCH upregulation was observed also in cases with no evidence of CNVs at NOTCH signaling genes, suggesting altered epigenetic modulation of the pathway. Notably, this was confirmed by microRNA expression analysis, that showed tumor-associated downregulation of the miR-200s and miR-34s families, correlated to NOTCH signaling and directly targeting NOTCH1. Total DNA from paraganglioma sample compared to total DNA from paired blood sample.
2013-08-21 | E-GEOD-49614 | biostudies-arrayexpress
Project description:Purpose: By integrating DNA methylation and gene expression of COPD lung tissues, we identified EPAS1 as a key regulator whose downstream genes significantly overlapped with multiple genes sets associated with COPD disease severity. EPAS1 is distinct in comparison with other key regulators in terms of methylation profiles and downstream target genes. Genes predicted to be regulated by EPAS1 were enriched for biological processes including signaling, cell communications, and system developement. As EPAS1 downstream genes were significantly enriched for hypoxia responsive genes in endothelial cells, we tested EPAS1 function in human and mouse endothelial cells HUVEC and C166. EPAS1 knockdown by siRNA in endothelial cells impacted genes that significantly overlapped with EPAS1 downstream genes in lung tissue including hypoxia responsive genes. Methods: The cell lines of HUVEC (Lonza, MD, USA) and C166 (American Type Culture Collection, VA, USA) were cultured in the appropriate media at 37M-BM-0C with 5% CO2. The cells were transfected with EPAS1 siRNA and non-targeting negative control siRNA (Life Technologies, CA, USA) using Lipofectamine RNAiMAX as recommended transfection protocols by the manufacturer. After the treatments with 5nM SilencerM-BM-. Select siRNA (s4700 for EPAS1, s65525 for Epas1; Life Technologies, USA) for 48 hours, the total RNA was purified with RNeasy Mini Kit (QIAGEN, Germany). The efficiencies of knocked down the EPAS1 expression were assessed by qPCR with 1.4% for HUVEC, 3.2% for C166. Approximately 250 ng of total RNA per sample were used for library construction by the TruSeq RNA Sample Prep Kit (Illumina) and sequenced using the Illumina HiSeq 2500 instrument with 100nt single read setting according to the manufacturer's instructions. Sequence reads were aligned to human genome assembly hg19 and mouse genome assembly mm10, respectively, using Tophat [96]. Total 23,228 human and 22,609 mouse genes were quantified using Cufflinks [96]. siRNA signatures were derived by comparing expression profiles of EPAS1 or Epas1 siRNAs with non-targeting siRNAs at paired t-test p-value cutoff 0.05 with resulting signature sizes of 2,796 and 3,730, and corresponding q-values [97] 0.11 and 0.07 for HUVEC and C166, respectively. Results: When comparing endothelial cells treated with EPAS1 siRNAs and scrambled siRNAs, we identified an EPAS1 siRNA signature consisting of 2796 and 3730 genes in human and mouse endothelial cell lines, respectively, whose expression levels significantly changed (t-test p-value<0.05), including EPAS1 itself (p-value = 0.002 and 0.02) and the EPAS1 downstream target gene VEGFA (p-value = 0.03 and 0.01). The EPAS1 siRNA signatures derived from human and mouse cell lines were highly consistent, with 695 genes in common to both signatures (p-value = 7.2x10-65). Both signatures not only significantly overlapped with EPAS1 downstream genes (p-value = 7.3x10-7 and 1.5x10-12), but also with hypoxia response genes in endothelial cells (FisherM-bM-^@M-^Ys Exact Test p-value = 5.8x10-8 and 1.2x10-12 in the human and mouse signatures, respectively). Moreover, the EPAS1 siRNA signatures consistently overlapped genes associated with the COPD severity phenotypes. These results together validate that EPAS1 causally regulates the downstream target genes we predicted, and that these genes in turn affect COPD development and progression. For each of human and mouse cell lines, 3 siRNA control cells, and 3 siRNA EPAS1 knockdown cells were used and analyzed. To identify EPAS1 signatures, paired t-test was performed between control siRNA and EPAS1 siRNA samples.
2015-01-16 | E-GEOD-62974 | biostudies-arrayexpress
Project description:BACKGROUND & AIMS: Recent studies revealed that hemoglobin is expressed in some non-erythrocytes and it suppresses oxidative stress when overexpressed. Oxidative stress plays a critical role in the pathogenesis of non-alcoholic steatohepatitis (NASH). This study was to investigate whether hemoglobin is expressed in hepatocytes and how it is related to oxidative stress in NASH patients. METHODS: Microarray was performed to identify differentially expressed genes in NASH. Quantitative real time PCR (qRT-PCR) was used to examine gene expression levels. Western blotting and immunofluorescence staining were employed to examine hemoglobin proteins. Flow cytometry was used to measure intracellular oxidative stress. RESULTS: Analysis of microarray gene expression data has revealed a significant increase in the expression of hemoglobin alpha (HBA1) and beta (HBB) in liver biopspies from NASH patients. Increased hemoglobin expression in NASH was validated by qRT-PCR. However, the expression of erythrocyte specific marker genes such as SPTA, SPTB, GYPA, GATA1, and ALAS2 did not change, indicating that increased hemoglobin expression in NASH was not from erythropoiesis, but could result from increased expression in hepatocytes. Immunofluorescence staining demonstrated positive HBA1 and HBB expression in the hepatocytes of NASH livers. Hemoglobin expression was also observed in human hepatocellular carcinoma HepG2 cell line. Furthermore, treatment with hydrogen peroxide, a known oxidative stress inducer, induced a dose dependent increase in HBA1 expression in HepG2 cells. Intriguingly, forced hemoglobin expression suppressed oxidative stress. CONCLUSIONS: Oxidative stress upregulates hemoglobin expression in hepatocytes. Suppression of oxidative stress by hemoglobin could be a mechanism to protect hepatocytes from oxidative damage. These findings suggest that hemoglobin is an inducible antioxidant in hepatocytes in response to increased oxidative stress as found in NASH livers. Twelve biopsy diagnosed NASH patients were included in this study. For control groups, total RNA from 5 different subjects were purchased from ADMET. These subjects are free from liver disease.
2010-10-20 | E-GEOD-24807 | biostudies-arrayexpress
Project description:Gene-centric CNV analysis of 24 individual paraganglioma cases identified a list of 104 genes most significantly targeted by tumor-associated alterations. The NOTCH signaling pathway was the most significantly enriched term in the list. Overexpression of the relevant NOTCH pathway proteins in sustentacular (glial), chief (neuroendocrine) and endothelial cells was confirmed by immunomorphological studies in 47 paragangliomas, including CNV-tested cases. NOTCH upregulation was observed also in cases with no evidence of CNVs at NOTCH signaling genes, suggesting altered epigenetic modulation of the pathway. Notably, this was confirmed by microRNA expression analysis, that showed tumor-associated downregulation of the miR-200s and miR-34s families, correlated to NOTCH signaling and directly targeting NOTCH1.
2013-08-21 | GSE49614 | GEO
Project description:To understand the role of the hypoxia-inducible transcription factor EPAS1 in regulating spermatogonial stem cell (SSC) function, a conditional knockout mouse was generated (EPAS1-cKO) where Epas1 was ablated only in the germ cells (Ddx4-Cre, Epasfl/-). For single cell RNA sequencing analysis, control and EPAS1-cKO males were pre-treated with the chemotherapeutic reagent busulfan to instigate regenerative conditions, and a germ cell-enriched cell population was collected 14 days later. Transcriptome profiling revealed that EPAS1 deficiency alters gene expression and key cellular processes in undifferentiated spermatogonia, including metabolism and proteostasis. Overall, these transcriptomic changes resulted in an impaired capacity for SSCs to restore spermatogenesis after busulfan treatment.
2023-11-08 | GSE235319 | GEO
Project description:Transcriptional profiling of mouse chondrocytes comparing chondrocytes infected with empty adenovirus and Epas1 adenovirus. RNA was extracted from each chondrocytes. We used microarrays to determine the effect of Epas1 overexpression on chondrocytes and identify the noble regulatory molecules during osteoarthritic pathogenesis.
2015-10-02 | GSE73659 | GEO
Project description:SNP profiles from 78 pheochromocytomas and paragangliomas were analyzed to detect copy number changes and LOH.
2012-09-11 | GSE38525 | GEO