Homo sapiens
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA147099 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Amplification of chromosomal region 11q13, containing the cell cycle regulatory gene CCND1, is frequently found in breast cancer and other malignancies. It is associated with the favourable oestrogen receptor (ER) positive breast tumour phenotype, but also with poor prognosis and treatment failure. 11q13 spans almost 14 Mb and contains more than 200 genes and is affected by various patterns of copy number gains, suggesting complex mechanisms and selective pressure during tumour progression. In the present study we used 32k tiling BAC array CGH to analyse 94 CCND1-amplified breast tumours from sporadic, hereditary and familial breast cancers to fine map chromosome 11q13. A set containing 281 CCND1-non-amplified breast tumours was used for comparisons. We used gene expression data to further validate the functional effect of gene amplification. We identified six core regions covering 11q13.1-q14.1 that were amplified in different combinations. The major core contained CCND1, whereas two cores were found proximal of CCND1 and three distal. The majority of the CCND1-amplified tumours were ER-positive and classified as luminal B. Furthermore, we found that CCND1 amplification is associated with a more aggressive phenotype within histological grade 2 tumours and luminal A subtype tumours. Amplification was equally prevalent in familial and sporadic tumours, but strikingly rare in BRCA1- and BRCA2- mutated tumours. We conclude that 11q13 includes many potential target genes in addition to CCND1. Genomic profiling of 94 CCND1-amplified breast tumors using tiling BAC aCGH. A number of cases were hybridized as replicates or replicate as dye-swaps.
2011-11-23 | E-GEOD-32578 | biostudies-arrayexpress
Project description:Amplification of chromosomal region 11q13, containing the cell cycle regulatory gene CCND1, is frequently found in breast cancer and other malignancies. It is associated with the favourable oestrogen receptor (ER) positive breast tumour phenotype, but also with poor prognosis and treatment failure. 11q13 spans almost 14 Mb and contains more than 200 genes and is affected by various patterns of copy number gains, suggesting complex mechanisms and selective pressure during tumour progression. In the present study we used 32k tiling BAC array CGH to analyse 94 CCND1-amplified breast tumours from sporadic, hereditary and familial breast cancers to fine map chromosome 11q13. A set containing 281 CCND1-non-amplified breast tumours was used for comparisons. We used gene expression data to further validate the functional effect of gene amplification. We identified six core regions covering 11q13.1-q14.1 that were amplified in different combinations. The major core contained CCND1, whereas two cores were found proximal of CCND1 and three distal. The majority of the CCND1-amplified tumours were ER-positive and classified as luminal B. Furthermore, we found that CCND1 amplification is associated with a more aggressive phenotype within histological grade 2 tumours and luminal A subtype tumours. Amplification was equally prevalent in familial and sporadic tumours, but strikingly rare in BRCA1- and BRCA2- mutated tumours. We conclude that 11q13 includes many potential target genes in addition to CCND1.
2011-11-23 | GSE32578 | GEO
Project description:Neuroblastoma is an embryonal neoplasm that remains of dramatic prognosis in its aggressive forms. Activating mutations of the ALK tyrosine kinase receptor have been identified in sporadic and familial cases of this cancer. We generated knock-in mice carrying the two most frequent Alk mutations observed in neuroblastoma patients. We used microarrays to detail the global programme of gene expression underlying the impact of ALK mutations on neuroblastoma formation in a MYCN amplified background. We selected several murine neuroblastoma tumors for RNA extraction and hybridization on Affymetrix microarrays. We generated three groups of tumors: 10 MYCN amplified tumors, 11 MYCN amplified/ALK F1174L tumors and 10 MYCN amplified/ALK R1275Q tumors.
2014-06-24 | E-GEOD-46583 | biostudies-arrayexpress
Project description:Recent insights into the role of the VHL tumor suppressor gene in hereditary and sporadic clear cell carcinoma of the kidney (ccRCC) have led to new treatments for patients with metastatic ccRCC, although virtually all patients eventually succumb to the disease. We performed an integrated, genome-wide analysis of copy-number changes and gene expression profiles in 90 tumors, including both sporadic and VHL disease-associated tumors, in hopes of identifying new therapeutic targets in ccRCC. We identified 14 regions of nonrandom copy-number change, including 7 regions of amplification (1q, 2q, 5q, 7q, 8q, 12p, and 20q) and 7 regions of deletion (1p, 3p, 4q, 6q, 8p, 9p, and 14q). An analysis aimed at identifying the relevant genes revealed VHL as one of 3 genes in the 3p deletion peak, CDKN2A and CDKN2B as the only genes in the 9p deletion peak, and MYC as the only gene in the 8q amplification peak. An integrated analysis to identify genes in amplification peaks that are consistently overexpressed among amplified samples confirmed MYC as a potential target of 8q amplification and identified candidate oncogenes in the other regions. A comparison of genomic profiles revealed that VHL disease-associated tumors are similar to a subgroup of sporadic tumors, and thus more homogeneous overall. Sporadic tumors without evidence of biallelic VHL inactivation fell into 2 groups: one group with genomic profiles highly dissimilar to the majority of ccRCC, and a second group with genomic profiles that are much more similar to tumors with biallelic inactivation of VHL. Keywords: comparative genomic hybridization
2009-06-02 | GSE14994 | GEO
Project description:<p>DNA Inverted Repeats as an At-risk Motif for Palindromic Gene Amplificatio defines oncogene amplification that is configured as a series of inverted duplications (palindromic gene amplification). There are several, recurrently amplified oncogenes throughout the human genome. However, it remains unclear whether this recurrent amplification is solely a manifestation of increased fitness resulting from random amplification mechanisms, or if genomic locus-specific amplification mechanism plays a role. </p> <p>In this study, we show that the ERBB2 oncogene at 17q12 is susceptible to palindromic gene amplification in HER2-positive breast tumors. We investigated eight tumors in this study, of which five tumors were HER2-positive, and three tumors were HER2-negative. HER2-status was determined by clinical FISH tests. We applied three genomic approaches to investigate the amplification mechanism: (1) copy number analysis by array-CGH on the Affymetrix SNP6.0 platform (8 files), (2) sequencing of DNA libraries enriched with tumor-derived palindromic DNA (Genome-wide Analysis of Palindrome Formation, GAPF-seq) (8 files) and (3) unbiased whole genome sequencing (WGS) (1 file). These molecular data is made available in the dbGaP. </p> <p>Genomic studies using tumor DNA was approved under the Internal Institutional Review Board at the Cleveland Clinic (IRB07-136: EXEMPT: Chromosome Breakage and DNA Palindrome Formation). Specimens were obtained and methods were carried out under the auspices of IRB 7881 (Evaluation of Genetic and Molecular Markers in Patients with Breast Cancer). All patients consented to allow their cancer specimens to be used by researchers in an anonymized fashion. The consent form indicates that publication will take place without identifiers to protect the identity of any specific individual.</p> <p>We observed significant and enrichment of palindromic DNA within amplified ERBB2 genomic segments in four out of five HER2-positive tumors. None of three HER2-negative tumors showed such enrichment. Palindromic DNA was particularly enriched at amplification peaks and boundaries between amplified and normal copy-number regions. Thus, palindromic gene amplification shaped the amplified ERBB2 locus. The moderate enrichment of palindromic DNA throughout the amplified segments leads us to propose that the ERBB2 locus is amplified through a mechanism that repeatedly generates palindromic DNA, such as Breakage-Fusion-Bridge cycles. Our results reveal a potential interaction between local genomic environments and gene amplification mechanisms. </p> <p>This study is published under the title "Palindromic amplification of the ERBB2 oncogene in primary HER2-positive breast tumors" <a href="https://www.ncbi.nlm.nih.gov/pubmed/?term=28211519" target="_blank">(PMID:28211519)</a>. </p>
| phs001261 | dbGaP
Project description:Recent insights into the role of the VHL tumor suppressor gene in hereditary and sporadic clear cell carcinoma of the kidney (ccRCC) have led to new treatments for patients with metastatic ccRCC, although virtually all patients eventually succumb to the disease. We performed an integrated, genome-wide analysis of copy-number changes and gene expression profiles in 90 tumors, including both sporadic and VHL disease-associated tumors, in hopes of identifying new therapeutic targets in ccRCC. We identified 14 regions of nonrandom copy-number change, including 7 regions of amplification (1q, 2q, 5q, 7q, 8q, 12p, and 20q) and 7 regions of deletion (1p, 3p, 4q, 6q, 8p, 9p, and 14q). An analysis aimed at identifying the relevant genes revealed VHL as one of 3 genes in the 3p deletion peak, CDKN2A and CDKN2B as the only genes in the 9p deletion peak, and MYC as the only gene in the 8q amplification peak. An integrated analysis to identify genes in amplification peaks that are consistently overexpressed among amplified samples confirmed MYC as a potential target of 8q amplification and identified candidate oncogenes in the other regions. A comparison of genomic profiles revealed that VHL disease-associated tumors are similar to a subgroup of sporadic tumors, and thus more homogeneous overall. Sporadic tumors without evidence of biallelic VHL inactivation fell into 2 groups: one group with genomic profiles highly dissimilar to the majority of ccRCC, and a second group with genomic profiles that are much more similar to tumors with biallelic inactivation of VHL. Keywords: comparative genomic hybridization 90 clear cell renal cell carcinomas and 21 renal cancer cell lines were subject to 250K SNP analysis.
2010-04-10 | E-GEOD-14994 | biostudies-arrayexpress
Project description:The let-7 microRNA families are tumor suppressors often deregulated in cancer, yet the underlying mechanisms of let-7 disruption remain poorly understood. Neuroblastoma is defined in part by poor prognosis associated with genetic amplification of MYCN, itself a let-7 target. The let-7 biogenesis inhibitor LIN28B has been implicated as a critical regulator of MYCN ; however, here we show that LIN28B is dispensable for both MYCN protein expression and growth of MYCN amplified neuroblastoma cell lines despite robust de-repression of let-7 . We further report that amplified MYCN mRNA is a potent let-7 sponge that through exceptionally high expression defines a sub-set of self-sponging amplified competing endogenous RNA (aceRNA) and reconciles the dispensability of LIN28B . In addition, we observe frequent genomic loss of let-7 that inversely associates with MYCN- amplification, providing an explanation for common, yet unresolved amplification-independent patterns of chromosome loss. We thus propose a model whereby let-7 disruption by genetic loss, LIN28B expression, or aceRNA sponging is a unifying mechanism of neuroblastoma pathogenesis. Indeed, our data show that the majority of neuroblastomas have at least one let-7 disruption event and that genetic loss in non-MYCN amplified tumors marks decreased survival, further underscoring its importance. The inverse relationship between allelic loss and sponging of let-7 from highly expressed or amplified oncogenes may have broad implications for oncogenesis.
2016-07-06 | GSE81499 | GEO
Project description:The let-7 microRNA families are tumor suppressors often deregulated in cancer, yet the underlying mechanisms of let-7 disruption remain poorly understood. Neuroblastoma is defined in part by poor prognosis associated with genetic amplification of MYCN, itself a let-7 target. The let-7 biogenesis inhibitor LIN28B has been implicated as a critical regulator of MYCN ; however, here we show that LIN28B is dispensable for both MYCN protein expression and growth of MYCN amplified neuroblastoma cell lines despite robust de-repression of let-7 . We further report that amplified MYCN mRNA is a potent let-7 sponge that through exceptionally high expression defines a sub-set of self-sponging amplified competing endogenous RNA (aceRNA) and reconciles the dispensability of LIN28B . In addition, we observe frequent genomic loss of let-7 that inversely associates with MYCN- amplification, providing an explanation for common, yet unresolved amplification-independent patterns of chromosome loss. We thus propose a model whereby let-7 disruption by genetic loss, LIN28B expression, or aceRNA sponging is a unifying mechanism of neuroblastoma pathogenesis. Indeed, our data show that the majority of neuroblastomas have at least one let-7 disruption event and that genetic loss in non-MYCN amplified tumors marks decreased survival, further underscoring its importance. The inverse relationship between allelic loss and sponging of let-7 from highly expressed or amplified oncogenes may have broad implications for oncogenesis.
2016-07-06 | GSE81498 | GEO
Project description:The let-7 microRNA families are tumor suppressors often deregulated in cancer, yet the underlying mechanisms of let-7 disruption remain poorly understood. Neuroblastoma is defined in part by poor prognosis associated with genetic amplification of MYCN, itself a let-7 target. The let-7 biogenesis inhibitor LIN28B has been implicated as a critical regulator of MYCN ; however, here we show that LIN28B is dispensable for both MYCN protein expression and growth of MYCN amplified neuroblastoma cell lines despite robust de-repression of let-7 . We further report that amplified MYCN mRNA is a potent let-7 sponge that through exceptionally high expression defines a sub-set of self-sponging amplified competing endogenous RNA (aceRNA) and reconciles the dispensability of LIN28B . In addition, we observe frequent genomic loss of let-7 that inversely associates with MYCN- amplification, providing an explanation for common, yet unresolved amplification-independent patterns of chromosome loss. We thus propose a model whereby let-7 disruption by genetic loss, LIN28B expression, or aceRNA sponging is a unifying mechanism of neuroblastoma pathogenesis. Indeed, our data show that the majority of neuroblastomas have at least one let-7 disruption event and that genetic loss in non-MYCN amplified tumors marks decreased survival, further underscoring its importance. The inverse relationship between allelic loss and sponging of let-7 from highly expressed or amplified oncogenes may have broad implications for oncogenesis.
2016-07-06 | GSE81497 | GEO
Project description:Gene expression profiling has discriminated between sporadic microsatellite instable (MSI) and microsatellite stable (MSS) colorectal cancers (CRCs), whereas the expression pattern of familial colorectal cancer type X (FCCTX) and Lynch syndrome (LS) associated CRCs remain largely unknown. The purpose of this study is to use gene expression profiling of formalin-fixed paraffin-embedded (FFPE) tumor specimens from FCCTX, LS and sporadic CRC as a control to detect expression patterns and to identify signaling pathways differing between FCCTX and LS tumors.
2012-03-08 | GSE36335 | GEO