Somatic focal copy number gains of noncoding regions of receptor tyrosine kinase genes in epileptogenic neurons
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ABSTRACT:
PROVIDER: PRJNA663597 | ENA |
REPOSITORIES: ENA
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Project description:Epilepsy is a heterogenous group of disorders defined by recurrent seizure activity due to abnormal synchronized activity of neurons. A growing number of epilepsy cases are believed to be caused by genetic factors and copy number variants (CNV) contribute to up to 5% of epilepsy cases. However, CNVs in epilepsy are usually large deletions or duplications involving multiple neurodevelopmental genes. Here we identify focal amplifications of regulatory regions of receptor tyrosine kinase genes as a genetic abnormality in epileptogenic brains. Whole genome DNA methylation profiling identified three main clusters of which one showed strong association with receptor tyrosine kinase genes. By copy number analysis, we identified focal copy number gains involving EGFR and PDGFRA in brain tissue of patients who underwent seizure focus resection for treatment-resistant epilepsy. The dysplastic neurons showed marked overexpression of pEGFR and pPDGFRA, while glial and endothelial cells were negative. Sequencing and DNA methylation analysis revealed that enhancer regions of EGFR and PDGFRA gene promoter were amplified, while coding regions did not show copy number abnormalities or somatic mutations. Our results identify somatic focal copy number gains of noncoding regulatory regions in the brain as a previously unrecognized genetic driver in epilepsy. Somatic copy number aberrations of regulatory regions represent a mechanism of abnormal activation of receptor tyrosine kinase genes in epilepsy. Upregulated receptor tyrosine kinases provide a potential avenue for therapy in seizure disorders.
2021-07-13 | GSE157989 | GEO
Project description:Epilepsy is a heterogenous group of disorders defined by recurrent seizure activity due to abnormal synchronized activity of neurons. A growing number of epilepsy cases are believed to be caused by genetic factors and copy number variants (CNV) contribute to up to 5% of epilepsy cases. However, CNVs in epilepsy are usually large deletions or duplications involving multiple neurodevelopmental genes. In patients who underwent seizure focus resection for treatment-resistant epilepsy, whole genome DNA methylation profiling identified 3 main clusters of which one showed strong association with receptor tyrosine kinase (RTK) genes. We identified focal copy number gains involving epidermal growth factor receptor (EGFR) and PDGFRA loci. The dysplastic neurons of cases with amplifications showed marked overexpression of EGFR and PDGFRA, while glial and endothelial cells were negative. Targeted sequencing of regulatory regions and DNA methylation analysis revealed that only enhancer regions of EGFR and gene promoter of PDGFRA were amplified, while coding regions did not show copy number abnormalities or somatic mutations. Somatic focal copy number gains of noncoding regulatory represent a previously unrecognized genetic driver in epilepsy and a mechanism of abnormal activation of RTK genes. Upregulated RTKs provide a potential avenue for therapy in seizure disorders.
| S-EPMC8502434 | biostudies-literature
Project description:Focal gains of VEGFA and molecular classification of hepatocellular carcinoma
| PRJNA103797 | ENA
Project description:Many human cancers present as multi-focal lesions. Understanding the clonal origin of multi-focal cancers is of both etiological and clinical importance. The molecular basis of multi-focal prostate cancer has previously been explored using only a limited number of isolated markers and, although independent origin is widely believed, the clonal origin of multi-focal prostate cancer is still debatable. We attempted to address clonal origin using a genome-wide copy-number analysis of individual cancer and high-grade prostatic intraepithelial neoplasia (HGPIN) lesions. Using Affymetrix array 6.0 copy-number analysis, we compared the genomic changes detected in 54 individual cancer and HGPIN lesions, isolated from 20 clinically localized prostate cancer cases. Identical genomic copy-number changes, shared by all same-case cancer foci, were detected in all 16 informative multi-tumor cases. In addition, both HGPIN lesions in the two multi-HGPIN cases available shared identical genomic changes. Commonly known genomic alterations, including losses at 6q15, 8p21.3-8p21.2, 10q23.2-10q23.31, 13q21.31-13q21.32, 16q22.3, 16q23.2-16q23.3 and 21q22.2-21q22.3 regions and gain of 8q24.3 were the most frequently detected changes in this multi-focal prostate cancer study, occurring in all same-case foci in at least one case. Microarray data were confirmed by fluorescence in situ hybridization in selected foci. Our high-resolution genome-wide copy-number data suggest that many multi-focal cases derive from a single prostate cancer precursor clone and that this precursor may give rise to separate HGPIN foci, which through clonal expansion may progress to multi-focal invasive prostate cancer. These findings, which demonstrate the monoclonal origin of multi-focal prostate cancer, should significantly enhance our understanding of prostate carcinogenesis and potentially improve clinical management of the disease.
2011-12-31 | GSE29569 | GEO
Project description:The landscape of somatic copy-number alterations (SCNAs) affecting long non-coding RNAs (lncRNAs) in human cancer remains largely unexplored. While the majority of lncRNAs remains to be functionally characterized, several have been implicated in cancer development and metastasis. Considering the plethora of lncRNAs genes that is currently reported, it is conceivable that several lncRNAs might function as oncogenes or tumor suppressor genes. We devised a strategy to detect focal lncRNA SCNAs using a custom DNA microarray platform probing 20 418 lncRNA genes. By screening a panel of 80 cancer cell lines, we detected numerous focal aberrations targeting one or multiple lncRNAs without affecting neighboring protein-coding genes. These focal aberrations are highly suggestive for a tumor suppressive or oncogenic role of the targeted lncRNA gene. Although functional validation remains an essential step in the further characterization of the involved candidate cancer lncRNAs, our results provide a direct way of prioritizing candidate lncRNAs involved in cancer pathogenesis.
2017-01-01 | GSE85444 | GEO
Project description:Many human cancers present as multi-focal lesions. Understanding the clonal origin of multi-focal cancers is of both etiological and clinical importance. The molecular basis of multi-focal prostate cancer has previously been explored using only a limited number of isolated markers and, although independent origin is widely believed, the clonal origin of multi-focal prostate cancer is still debatable. We attempted to address clonal origin using a genome-wide copy-number analysis of individual cancer and high-grade prostatic intraepithelial neoplasia (HGPIN) lesions. Using Affymetrix array 6.0 copy-number analysis, we compared the genomic changes detected in 54 individual cancer and HGPIN lesions, isolated from 20 clinically localized prostate cancer cases. Identical genomic copy-number changes, shared by all same-case cancer foci, were detected in all 16 informative multi-tumor cases. In addition, both HGPIN lesions in the two multi-HGPIN cases available shared identical genomic changes. Commonly known genomic alterations, including losses at 6q15, 8p21.3-8p21.2, 10q23.2-10q23.31, 13q21.31-13q21.32, 16q22.3, 16q23.2-16q23.3 and 21q22.2-21q22.3 regions and gain of 8q24.3 were the most frequently detected changes in this multi-focal prostate cancer study, occurring in all same-case foci in at least one case. Microarray data were confirmed by fluorescence in situ hybridization in selected foci. Our high-resolution genome-wide copy-number data suggest that many multi-focal cases derive from a single prostate cancer precursor clone and that this precursor may give rise to separate HGPIN foci, which through clonal expansion may progress to multi-focal invasive prostate cancer. These findings, which demonstrate the monoclonal origin of multi-focal prostate cancer, should significantly enhance our understanding of prostate carcinogenesis and potentially improve clinical management of the disease. Copy number analysis of Affymetrix SNP 6.0 array was performed for a total of 48 cancer and HGPIN lesions from 18 prostate cancer cases. All samples have case-matched normal controls. PL = high grade PIN from left side, PR = high grade PIN from right side, PM = high grade PIN from middle of the tissue, TL = tumour from left side, TR = tumour from right side.
2011-12-31 | E-GEOD-29569 | biostudies-arrayexpress
Project description:To characterize the genetic alterations that instigate hepatitis C virus-induced hepatocellular carcinoma (HCC), we conducted an integrative genomic analysis of 103 HCCs. Most tumors harbored 1q gain, 8q gain or 8p loss, with occasional alterations in 13 additional chromosome arms. In addition to amplifications at 11q13 in 6 tumors, 4 tumors harbored focal gains at 6p21 incorporating VEGFA, which were confirmed in 4 of 113 HCC in an independent validation set. Strikingly, this locus overlapped with copy gains in 4 of 371 lung adenocarcinomas. Overexpression of VEGFA via 6p21 gain suggested a cell-nonautonomous mechanism of oncogene activation. Hierarchical clustering of gene expression among 91 tumors identified 5 classes, including ‘Wnt-CTNNB1’, ‘proliferation’ and ‘interferon-related’ gene classes. We also discovered a novel class defined by polysomy of chromosome 7, gains of which were associated with early tumor recurrence after resection. These findings reveal key alterations in HCC pathogenesis and implicate potential therapeutic targets. Keywords: disease state analysis
2008-06-22 | GSE9845 | GEO
Project description:Duplications of the Xq28 region are the most frequent chromosomal aberrations observed in patients with intellectual disability (ID), especially in males. These duplications occur by variable mechanisms, including interstitial duplications mediated by segmental duplications in this region and terminal duplications (functional disomy) derived from translocation with other chromosomes. The most commonly duplicated region includes methyl CpG-binding protein 2 gene (MECP2), which has a minimal duplicated size of 0.2?Mb. Patients with MECP2 duplications show severe ID, intractable seizures and recurrent infections. Duplications in the telomeric neighboring regions, which include GDP dissociation inhibitor 1 gene (GDI1) and ras-associated protein RAB39B gene (RAB39B), are independently associated with ID, and many segmental duplications located in this region could mediate these frequently observed interstitial duplications. In addition, large duplications, including MECP2 and GDI1, induce hypoplasia of the corpus callosum. Abnormalities observed in the white matter, revealed by brain magnetic resonance imaging, are a common finding in patients with MECP2 duplications. As primary sequence analysis cannot be used to determine the region responsible for chromosomal duplication syndrome, finding this region relies on the collection of genotype-phenotype data from patients.
| S-EPMC4785515 | biostudies-literature
Project description:We investigated the frequency and function of mutations and increased copy number of the PIK3CA gene in lung cancers. PIK3CA mutations are one of the most common gene changes present in human cancers. We analyzed the mutational status of exons 9 and 20 and gene copy number of PIK3CA using 86 non-small cell lung cancer (NSCLC) cell lines, 43 small cell lung cancer (SCLC) cell lines, 3 extrapulmonary small cell cancer (ExPuSC) cell lines, and 691 resected NSCLC tumors and studied the relationship between PIK3CA alterations and mutational status of epidermal growth factor receptor (EGFR) signaling pathway genes (EGFR, KRAS, HER2, and BRAF). We also determined PIK3CA expression and activity and correlated the findings with effects on cell growth. We identified mutations in 4.7% of NSCLC cell lines and 1.6% of tumors of all major histologic types. Mutations in cell lines of small cell origin were limited to two ExPuSC cell lines. PIK3CA copy number gains were more frequent in squamous cell carcinoma (33.1%) than in adenocarcinoma (6.2%) or SCLC lines (4.7%). Mutational status of PIK3CA was not mutually exclusive to EGFR or KRAS. PIK3CA alterations were associated with increased phosphatidylinositol 3-kinase activity and phosphorylated Akt expression. RNA interference-mediated knockdown of PIK3CA inhibited colony formation of cell lines with PIK3CA mutations or gains but was not effective in PIK3CA wild-type cells. PIK3CA mutations or gains are present in a subset of lung cancers and are of functional importance.
| S-EPMC2874836 | biostudies-other
Project description:To characterize the genetic alterations that instigate hepatitis C virus-induced hepatocellular carcinoma (HCC), we conducted an integrative genomic analysis of 103 HCCs. Most tumors harbored 1q gain, 8q gain or 8p loss, with occasional alterations in 13 additional chromosome arms. In addition to amplifications at 11q13 in 6 tumors, 4 tumors harbored focal gains at 6p21 incorporating VEGFA, which were confirmed in 4 of 113 HCC in an independent validation set. Strikingly, this locus overlapped with copy gains in 4 of 371 lung adenocarcinomas. Overexpression of VEGFA via 6p21 gain suggested a cell-nonautonomous mechanism of oncogene activation. Hierarchical clustering of gene expression among 91 tumors identified 5 classes, including ‘Wnt-CTNNB1’, ‘proliferation’ and ‘interferon-related’ gene classes. We also discovered a novel class defined by polysomy of chromosome 7, gains of which were associated with early tumor recurrence after resection. These findings reveal key alterations in HCC pathogenesis and implicate potential therapeutic targets. Keywords: disease state analysis 103 hepatocellular carcinomas and 95 adjacent cirrhotic, non-tumoral liver tissue were obtained at the time of surgical resection of orthotopic transplantation.
2008-06-21 | E-GEOD-9845 | biostudies-arrayexpress