Landscape of somatic allelic imbalances and copy number alterations in HER2-amplified breast cancer
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE31645 | GEO | 2011/12/02
SECONDARY ACCESSION(S): PRJNA145413
REPOSITORIES: GEO
Similar Datasets
Project description:A survey of the somatic allelic imbalances and copy number alterations in HER2-amplified breast cancer. Genomic profiling of 26 breast tumors with amplification of HER2 using 1M and 2.5M Illumina SNP beadchips. Sample identifiers correspond to GSE21259 where sample annotations may be extracted.
2011-12-02 | E-GEOD-31645 | biostudies-arrayexpress
Project description:INTRODUCTION: Human epidermal growth factor receptor 2 (HER2)-amplified breast cancer represents a clinically well-defined subgroup due to availability of targeted treatment. However, HER2-amplified tumors have been shown to be heterogeneous at the genomic level by genome-wide microarray analyses, pointing towards a need of further investigations for identification of recurrent copy number alterations and delineation of patterns of allelic imbalance. METHODS: High-density whole genome array-based comparative genomic hybridization (aCGH) and single nucleotide polymorphism (SNP) array data from 260 HER2-amplified breast tumors or cell lines, and 346 HER2-negative breast cancers with molecular subtype information were assembled from different repositories. Copy number alteration (CNA), loss-of-heterozygosity (LOH), copy number neutral allelic imbalance (CNN-AI), subclonal CNA and patterns of tumor DNA ploidy were analyzed using bioinformatical methods such as genomic identification of significant targets in cancer (GISTIC) and genome alteration print (GAP). The patterns of tumor ploidy were confirmed in 338 unrelated breast cancers analyzed by DNA flow cytometry with concurrent BAC aCGH and gene expression data. RESULTS: A core set of 36 genomic regions commonly affected by copy number gain or loss was identified by integrating results with a previous study, together comprising > 400 HER2-amplified tumors. While CNN-AI frequency appeared evenly distributed over chromosomes in HER2-amplified tumors, not targeting specific regions and often < 20% in frequency, the occurrence of LOH was strongly associated with regions of copy number loss. HER2-amplified and HER2-negative tumors stratified by molecular subtypes displayed different patterns of LOH and CNN-AI, with basal-like tumors showing highest frequencies followed by HER2-amplified and luminal B cases. Tumor aneuploidy was strongly associated with increasing levels of LOH, CNN-AI, CNAs and occurrence of subclonal copy number events, irrespective of subtype. Finally, SNP data from individual tumors indicated that genomic amplification in general appears as monoallelic, that is, it preferentially targets one parental chromosome in HER2-amplified tumors. CONCLUSIONS: We have delineated the genomic landscape of CNAs, amplifications, LOH, and CNN-AI in HER2-amplified breast cancer, but also demonstrated a strong association between different types of genomic aberrations and tumor aneuploidy irrespective of molecular subtype.
| S-EPMC3326571 | biostudies-literature
Project description:Lung cancer is the worldwide leading cause of death from cancer. This GEO series correspond to one of the BAC aCGH data sets used as validation cohort for the study: Landscape of somatic allelic imbalances and copy number alterations in human lung cancer, Int J Cancer 2013.
2012-10-09 | GSE29065 | GEO
Project description:Lung cancer is the worldwide leading cause of death from cancer. This GEO series correspond to one of the BAC aCGH data sets used as validation cohort for the study: Landscape of somatic allelic imbalances and copy number alterations in human lung cancer, Int J Cancer 2012. Genomic profiling of 78 lung carcinomas using 32K BAC aCGH microarrays.
2012-10-09 | E-GEOD-29065 | biostudies-arrayexpress
Project description:A SNP microarray and FISH-based procedure to detect allelic imbalances in multiple myeloma: an integrated genomics approach reveals a wide dosage effect on gene and microRNA expression This SuperSeries is composed of the following subset Series: GSE13591: Integrated genomics approach to detect allelic imbalances in multiple myeloma GSE16121: Integrated genomics approach to detect allelic imbalances in multiple myeloma, SNP data Refer to individual Series
2009-05-16 | E-GEOD-16122 | biostudies-arrayexpress
Project description:A SNP microarray and FISH-based procedure to detect allelic imbalances in multiple myeloma: an integrated genomics approach reveals a wide dosage effect on gene and microRNA expression Multiple myeloma (MM) is characterized by marked genomic instability. Beyond structural rearrangements, a relevant role in its biology is represented by allelic imbalances leading to significant variations in ploidy status. To better elucidate the genomic complexity of MM, we analyzed a panel of 45 patients using combined FISH and microarray approaches. Using a self-developed procedure to infer exact local copy numbers for each sample, we identified a significant fraction of patients showing marked aneuploidy. A conventional clustering analysis showed that aneuploidy, chromosome 1 alterations, hyperdiploidy and recursive deletions at 1p and chromosomes 13, 14 and 22 were the main aberrations driving samples grouping. Then, we integrated mapping information with gene and microRNAs expression profiles: a multiclass analysis of the identified clusters showed a marked gene-dosage effect, particularly concerning 1q transcripts, also confirmed by correlating gene expression levels and local copy number alterations. A wide dosage effect affected also microRNAs, indicating that structural abnormalities in MM closely reflect in their expression imbalances. Finally, we identified several loci in which genes and microRNAs expression correlated with loss-of-heterozygosity occurrence. Our results provide insights into the composite network linking genome structure and gene/microRNA transcriptional features in MM. Keywords: Integrated genomics approach based on SNP microarray and FISH procedures to detect allelic imbalances in multiple myeloma.
2009-05-16 | GSE16121 | GEO
Project description:Comparison between germline (blood) and microdissected bladder tumors to determine allelic imbalances. The GeneChip® Mapping 10K Early Access Array Affymetrix, Santa Clara, CA was used to determine the number of heterozygous SNPs in DNA from blood compared to the number of heterozygous SNPs in DNA from tumor in the same patient. Keywords: repeat sample
2005-04-15 | GSE2258 | GEO
Project description:A SNP microarray and FISH-based procedure to detect allelic imbalances in multiple myeloma: an integrated genomics approach reveals a wide dosage effect on gene and microRNA expression This SuperSeries is composed of the SubSeries listed below.
2009-05-16 | GSE16122 | GEO
Project description:Multiple myeloma (MM) is characterized by marked genomic instability. Beyond structural rearrangements, a relevant role in its biology is represented by allelic imbalances leading to significant variations in ploidy status. To better elucidate the genomic complexity of MM, we analyzed a panel of 45 patients using combined FISH and microarray approaches. Using a self-developed procedure to infer exact local copy numbers for each sample, we identified a significant fraction of patients showing marked aneuploidy. A conventional clustering analysis showed that aneuploidy, chromosome 1 alterations, hyperdiploidy and recursive deletions at 1p and chromosomes 13, 14 and 22 were the main aberrations driving samples grouping. Then, we integrated mapping information with gene and microRNAs expression profiles: a multiclass analysis of the identified clusters showed a marked gene-dosage effect, particularly concerning 1q transcripts, also confirmed by correlating gene expression levels and local copy number alterations. A wide dosage effect affected also microRNAs, indicating that structural abnormalities in MM closely reflect in their expression imbalances. Finally, we identified several loci in which genes and microRNAs expression correlated with loss-of-heterozygosity occurrence. Our results provide insights into the composite network linking genome structure and gene/microRNA transcriptional features in MM. Keywords: Integrated genomics approach based on SNP microarray and FISH procedures to detect allelic imbalances in multiple myeloma.
2009-04-14 | GSE13591 | GEO
Project description:Comparison between germline (blood) and microdissected bladder tumors to determine allelic imbalances. The GeneChip® Mapping 10K Early Access Array Affymetrix, Santa Clara, CA was used to determine the number of heterozygous SNPs in DNA from blood compared to the number of heterozygous SNPs in DNA from tumor in the same patient.
2010-06-10 | E-GEOD-2258 | biostudies-arrayexpress