CaArray_gray-00298: Genomic and transcriptional aberrations linked to breast cancer pathophysiologies - Genome Copy Number (Scanning and OncoBAC)
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE69035 | GEO | 2015/05/20
SECONDARY ACCESSION(S): PRJNA284371
REPOSITORIES: GEO
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Project description:Tumor recurrence represents a significant clinical challenge in the treatment and management of breast cancer. To investigate whether copy number aberrations (CNAs) facilitate the re-emergence of tumor growth from residual disease we performed array comparative genomic hybridization (aCGH) on primary and recurrent mammary tumors from an inducible mouse model of type-I insulin-like growth factor receptor (IGF-IR) driven breast cancer. This genome-wide analysis revealed primary and recurrent tumors harbored distinct copy number aberrations (CNAs) with relapsed tumors containing an increased number of gene-level gains and losses. Remarkably, CNAs detected in primary tumors were largely devoid of annotated cancer genes while the vast majority of recurrent tumors harbored at least one CNA containing a known oncogene or tumor suppressor. Specifically, a subset of recurrent tumors carried gains at 6qA2 and 9qA2 which encode the Met and Yap1 oncogenes respectively. The most frequent CNA detected was a focal deletion at 4qC5 involving the Cdkn2a and Cdkn2b tumor suppressor genes. Integrative analysis revealed positive correlations between gene copy number and mRNA expression suggesting Met, Yap1 and Cdkn2a/b may serve as potential driver genes that promote tumor recurrence. Together, these findings indicate that tumor recurrence is facilitated by the acquisition of CNAs with oncogenic potential and provide a framework to dissect the molecular mechanisms that mediate tumor escape from dormancy.
2018-11-28 | GSE120186 | GEO
Project description:Large but not small copy-number alterations correlate to high-risk genomic aberrations and survival in chronic lymphocytic leukemia: a high-resolution genomic screening of newly diagnosed patients. Single nucleotide polymorphism (SNP)-arrays allow simultaneous detection of copy-number aberrations (CNAs) and copy-number neutral loss-of-heterozygosity (CNN-LOH). In this study we investigated the presence of CNAs and CNN-LOH in newly diagnosed CLL samples from a Swedish chronic lymphocytic leukemia (CLL) cohort. In this study we could detect the known recurrent aberrations in CLL (i.e. deletions of 13q, 11q, 17p and trisomy 12). We also detected other both large and small CNAs which were mostly non-recurrent. CNN-LOH was detected on chromosome 13q in patients that carried homozygous deletion of 13q.
2009-11-23 | GSE16406 | GEO
Project description:Diffuse large B-cell lymphoma (DLBCL) is a clinically and biologically heterogeneous disease. We have characterized recurrent copy number alterations (CNAs) in a large series of primary DLBCLs with HD-SNP arrays and the GISTIC algromithm. We evaluated the associations between transcript abundance and the presence of specific CNAs by obtaining RNA profiles on the majority of the primary DLBCLs and integrating the gene expression profiles with the copy number data.
2012-09-12 | GSE34171 | GEO
Project description:In order to screen potential novel 'driver genes' in lung cancer in Xuanwei (LCXW), genome-wide DNA copy number alterations (CNAs) were detected on 8 paired LCXW and non-cancerous lung (NCL) tissues by array-based comparative genomic hybridization microarrays. The log2 copy-number ratio calculation and CNA calls were determined using segMNT algorithm in NimbleScan. Log2 ratio test/control thresholds of 0.25 and -0.25 were defined as copy number gains and losses, respectively. Deviant signal intensity ratios involving 5 or more neighboring probes were considered as genomic aberrations. A large number of CNAs and DEGs were detected, respectively. Many recurrent CNAs were screened out, including gains at 5p15.33-p15.32, 5p15.1-p14.3 and 5p14.3-p14.2, and losses at 11q24.3, 21q21.1, 21q22.12-q22.13 and 21q22.2.
2016-10-22 | GSE89046 | GEO
Project description:Screening for gene copy-number alterations (CNAs) has improved by applying genome-wide microarrays, where SNP arrays also allow analysis of loss of heterozygozity (LOH). We here analyzed 10 chronic lymphocytic leukemia (CLL) samples using four different high-resolution platforms: BAC arrays (32K), oligonucleotide arrays (185K, Agilent), and two SNP arrays (250K, Affymetrix and 317K, Illumina). Cross-platform comparison revealed 29 concordantly detected CNAs, including known recurrent alterations, which confirmed that all platforms are powerful tools when screening for large aberrations. However, detection of 32 additional regions present in 2-3 platforms illustrated a discrepancy in detection of small CNAs, which often involved reported copy-number variations. LOH analysis revealed concordance of mainly large regions, but showed numerous, small nonoverlapping regions and LOH escaping detection. Evaluation of baseline variation and copy-number ratio response showed the best performance for the Agilent platform and confirmed the robustness of BAC arrays. Accordingly, these platforms demonstrated a higher degree of platform-specific CNAs. The SNP arrays displayed higher technical variation, although this was compensated by high density of elements. Affymetrix detected a higher degree of CNAs compared to Illumina, while the latter showed a lower noise level and higher detection rate in the LOH analysis. Large-scale studies of genomic aberrations are now feasible, but new tools for LOH analysis are requested.
2008-12-10 | GSE13557 | GEO
Project description:Neuroblastoma (NB) is an aggressive tumor that affects both infants and children. The disease outcome is greatly influenced by age of patient, stage, chromosome copy number aberrations (CNAs) and gene expression abnormalities. We analyzed, by microarray technology, genome and transcriptome of 3 groups of tumors of patients with metastatic disease: G1, stage 4S and MYCN single copy; G2, stage 4 younger than 18 months of age, MYCN single copy with no disease progression and G3, stage 4, older than 19 months, with unfavorable outcome. We found an accumulation of structural copy number aberrations (CNAs) in G3 whereas G1 tumors had mostly numerical (N) CNAs and G2 showed an intermediate behavior. Pair wise comparisons demonstrated that the average of N CNAs significantly decreased from G1 to G2 to G3 (9.6 G1 < 7.2 G2 < 3.6 G3); in contrast S CNAs significantly increased in G3 (0.7 G1 < 3.7 G2 < 7.0 G3). Interestingly, we observed several intra-chromosomal rearrangements in G3 tumors on chromosomes not usually involved in NB. Excluding MYCN amplified tumors by G3 we found a high frequency of S CNAs in this group. Gene expression analysis showed a deregulation of downstream genes of Ras and Rho signaling pathway among the 3 groups. It has been also observed a progressive switch off of development and adhesion genes and a switch on of cell cycle genes from G1 to G2 to G3. Moreover, the telemorase genes were significantly expressed in G3 with respect to remaining groups. Present data show an accumulation of S CNAs from stage 4S to 4. The deregulation of genes Rho/Ras pathway may explain the increase of tumor aggressiveness from G1 to G2 to G3. The increase of cell cycle and telomerase genes expression associated with G3 would provide unlimited replicative potential for these tumors and may be responsible for accumulation of S CNAs. Finally, we can argue that accumulation of structural aberrations and gene deregulation is age-dependent and it is associated with a more aggressive tumor phenotype. We analyzed 133 samples of metastatic neuroblastoma from patients divided into three groups: G1 49 patients stage 4S and MYCN single copy; G2 37 patients stage 4 younger than 18 months of age at diagnosis, MYCN single copy with no disease progression; G3 47 patients stage 4 older than 19 months of age at diagnosis, with unfavorable outcome.
2012-01-01 | E-GEOD-25771 | biostudies-arrayexpress
Project description:Screening for gene copy-number alterations (CNAs) has improved by applying genome-wide microarrays, where SNP arrays also allow analysis of loss of heterozygozity (LOH). We here analyzed 10 chronic lymphocytic leukemia (CLL) samples using four different high-resolution platforms: BAC arrays (32K), oligonucleotide arrays (185K, Agilent), and two SNP arrays (250K, Affymetrix and 317K, Illumina). Cross-platform comparison revealed 29 concordantly detected CNAs, including known recurrent alterations, which confirmed that all platforms are powerful tools when screening for large aberrations. However, detection of 32 additional regions present in 2-3 platforms illustrated a discrepancy in detection of small CNAs, which often involved reported copy-number variations. LOH analysis revealed concordance of mainly large regions, but showed numerous, small nonoverlapping regions and LOH escaping detection. Evaluation of baseline variation and copy-number ratio response showed the best performance for the Agilent platform and confirmed the robustness of BAC arrays. Accordingly, these platforms demonstrated a higher degree of platform-specific CNAs. The SNP arrays displayed higher technical variation, although this was compensated by high density of elements. Affymetrix detected a higher degree of CNAs compared to Illumina, while the latter showed a lower noise level and higher detection rate in the LOH analysis. Large-scale studies of genomic aberrations are now feasible, but new tools for LOH analysis are requested. 10 chronic lymphocytic leukemia (CLL) samples was analyzed using four different high-resolution platforms: 32K BAC arrays, 185K Agilent oligonucleotide arrays, 250K Affymetrix SNP arrays and 317K Illumina SNP arrays.
2008-12-10 | E-GEOD-13557 | biostudies-arrayexpress
Project description:The ETV6/RUNX1 fusion gene, present in 25% of B-lineage childhood acute lymphoblastic leukemia (ALL), is thought to represent an initiating event, which requires additional genetic changes for leukemia development. To identify additional genetic alterations, 24 ETV6/RUNX1-positive ALLs were analyzed using 500K single nucleotide polymorphism arrays. The results were combined with previously published data sets, allowing us to ascertain genomic copy number aberrations (CNAs) in 164 cases. In total, 45 recurrent CNAs were identified with an average number of 3.5 recurrent changes per case (range 0-13). Twenty-six percent of cases displayed a set of recurrent CNAs identical to that of other cases in the data set. The majority (74%), however, displayed a unique pattern of recurrent CNAs, indicating a large heterogeneity within this ALL subtype. As previously demonstrated, alterations targeting genes involved in B-cell development were common (present in 28% of cases). However, the combined analysis also identified alterations affecting nuclear hormone response (24%) to be a characteristic feature of ETV6/RUNX1-positive ALL. Studying the correlation pattern of the CNAs allowed us to highlight significant positive and negative correlations between specific aberrations. Furthermore, oncogenetic tree models identified ETV6, CDKN2A/B, PAX5, del(6q), and +16 as possible early events in the leukemogenic process.
2010-07-07 | GSE19996 | GEO
Project description:The ETV6/RUNX1 fusion gene, present in 25% of B-lineage childhood acute lymphoblastic leukemia (ALL), is thought to represent an initiating event, which requires additional genetic changes for leukemia development. To identify additional genetic alterations, 24 ETV6/RUNX1-positive ALLs were analyzed using 500K single nucleotide polymorphism arrays. The results were combined with previously published data sets, allowing us to ascertain genomic copy number aberrations (CNAs) in 164 cases. In total, 45 recurrent CNAs were identified with an average number of 3.5 recurrent changes per case (range 0-13). Twenty-six percent of cases displayed a set of recurrent CNAs identical to that of other cases in the data set. The majority (74%), however, displayed a unique pattern of recurrent CNAs, indicating a large heterogeneity within this ALL subtype. As previously demonstrated, alterations targeting genes involved in B-cell development were common (present in 28% of cases). However, the combined analysis also identified alterations affecting nuclear hormone response (24%) to be a characteristic feature of ETV6/RUNX1-positive ALL. Studying the correlation pattern of the CNAs allowed us to highlight significant positive and negative correlations between specific aberrations. Furthermore, oncogenetic tree models identified ETV6, CDKN2A/B, PAX5, del(6q), and +16 as possible early events in the leukemogenic process. Affymetrix SNP arrays were performed according to the manufacturer's directions on DNA extracted from 23 leukemic bone marrow samples and one ETV6/RUNX1-positive cell line.
2010-07-07 | E-GEOD-19996 | biostudies-arrayexpress
Project description:Cancer is a genetic disease with frequent somatic alterations in DNA. Study of recurrent copy number aberrations (CNAs) in human cancers would enable the elucidation of disease mechanisms and the identification of key oncogenic drivers with causal roles in oncogenesis. We have comprehensively and systematically characterized CNAs and accompanied gene expression changes in the tumors and their matched non-tumor liver tissues from 286 hepatocellular carcinoma (HCC) patients. Our analysis identified 29 recurrently amplified regions and 22 deleted regions with a high level of copy number changes, harboring established oncogenes and tumor suppressors, including CCND1, MET, CDKN2A and CDKN2B, as well as many other genes not previously reported to be involved in liver carcinogenesis. Cis-acting genes in the amplification and deletion peaks were enriched in core cancer pathways, including cell cycle, p53, PI3K, MAPK, Wnt and TGFβ signaling in large proportions of HCCs. We further validated two candidate driver genes, BCL9 and MTDH, from the recurrent focal amplification peaks and showed that they play a significant role in HCC growth and survival. In summary, we have demonstrated that characterizing the CNA landscape in HCC will facilitate the understanding of disease mechanisms and the identification of oncogenic drivers that may serve as potential therapeutic targets for the treatment of this devastating disease. Thirty hepatocellular carcinoma cell lines were genotyped using Illumina HumanOmni1-Quad BeadChip to estimate their copy number profiles relative to pooled Hapmap samples.
2013-05-22 | E-GEOD-38207 | biostudies-arrayexpress