Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Non-invasive detection of genome-wide somatic copy number alterations by liquid biopsies.

ABSTRACT: Liquid biopsies, i.e. the analysis of circulating tumor cells (CTCs) or circulating tumor DNA (ctDNA), are evolving into promising clinical tools. Indeed, a plethora of liquid biopsy technologies to deduce non-invasively characteristics of the tumor genome from the peripheral blood have been developed over the last few years. For example, liquid biopsies have been used to assess the tumor burden, to monitor the evolution of tumor genomes, to unravel mechanisms of resistance, to establish the tumor heterogeneity, and for the identification of prognostic and predictive markers. In this review we focus on methods to establish genome-wide profiles of somatic copy number alterations (SCNAs) from plasma DNA and show how they provide novel insights into the biology of cancer and their impact on the management of patients.

SUBMITTER: Heitzer E

PROVIDER: S-EPMC5528970 | biostudies-other | 2016 Mar

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Similar Datasets

LiquidCNA: Tracking subclonal evolution from longitudinal liquid biopsies using somatic copy number alterations.

Project description:Cell-free DNA (cfDNA) measured via liquid biopsies provides a way for minimally invasive monitoring of tumor evolutionary dynamics during therapy. Here we present liquidCNA, a method to track subclonal evolution from longitudinally collected cfDNA samples sequenced through cost-effective low-pass whole-genome sequencing. LiquidCNA utilizes somatic copy number alteration (SCNA) to simultaneously genotype and quantify the size of the dominant subclone without requiring B-allele frequency information, matched-normal samples, or prior knowledge on the genetic identity of the emerging clone. We demonstrate the accuracy of liquidCNA in synthetically generated sample sets and in vitro mixtures of cancer cell lines. In vivo application in patients with metastatic lung cancer reveals the progressive emergence of a novel tumor subpopulation. LiquidCNA is straightforward to use, is computationally inexpensive, and enables continuous monitoring of subclonal evolution to understand and control-therapy-induced resistance.

| S-EPMC8350516 | biostudies-literature

Genome-Wide Analysis of Somatic Copy Number Alterations and Gene Expression in Metastatic Melanoma

Project description:This SuperSeries is composed of the SubSeries listed below. Refer to individual Series

| S-ECPF-GEOD-23056 | biostudies-other

Genome-Wide Analysis of Somatic Copy Number Alterations and Gene Expression in Metastatic Melanoma: RNA-Seq

Project description:All cancers are diseases of the genome. A combination of somatic point mutations, focal amplifications and deletions, and chromosome level aberrations conspire to disrupt gene expression and the interplay between signaling pathways that control normal growth and tissue homeostasis. Here we investigate transcript levels in 7 melanomas and a pool of melanocytes. The transcriptome from 7 cutaneous melanomas and a pool of 2 normal melanocyte cultures was sequenced using the 454 technology

| S-ECPF-GEOD-22932 | biostudies-other

Genome-Wide Somatic Copy Number Alterations and Mutations in High-Grade Pancreatic Intraepithelial Neoplasia.

Project description:To obtain a better understanding of the genetic alterations of high-grade pancreatic intraepithelial neoplasia (HG-PanIN), we performed whole-genome copy number analysis by using single nucleotide polymorphism microarrays and targeted next-generation sequencing of 11 microdissected HG-PanIN and two low-grade PanIN lesions associated with HG-PanIN. HG-PanIN mutation profiles were compared with those of their associated invasive pancreatic ductal adenocarcinoma. All PanIN lesions harbored somatic KRAS mutations. The most common copy number losses in the HG-PanIN were at the CDKN2A (9p21), TP53 (17p13), and SMAD4 (18q21) loci. Chromosomal losses in HG-PanIN were also found at 6p25-p24, 6q11-q27, 12q24, and 17q23-q24. Biallelic inactivation of CDKN2A and TP53 was detected in five of eight and in three of eight evaluable PanIN lesions, respectively. None of the HG-PanIN lesions had SMAD4 mutations or homozygous deletion. Copy number gains were noted at the MYC (8q24) and CCNE1 (19q12) loci and at 1q25-q31. Four HG-PanINs and one low-grade PanIN harbored chromothripsis-like regions. Five of seven pancreatic ductal adenocarcinomas evaluated had additional mutations that were not found in their associated HG-PanIN. HG-PanIN harbors widespread copy number alterations and commonly shows evidence of biallelic inactivation of CDKN2A and TP53 but not SMAD4. Chromothripsis events contribute to the copy number alterations of HG-PanIN.

| S-EPMC6024190 | biostudies-literature

Molecular profiling and genome-wide analysis based on somatic copy number alterations in advanced colorectal cancers.

Project description:To characterize somatic alterations in colorectal cancer (CRC), we conducted a genome-scale analysis of 106 CRC specimens. We assessed comprehensive somatic copy number alterations (SCNAs) in these CRC specimens. In addition, we examined microsatellite instability (MSI; low and high), genetic mutations (KRAS, BRAF, TP53, and PIK3CA), and DNA methylation status (classified into low, intermediate, and high type). We stratified molecular alterations in the CRCs using a hierarchical cluster analysis.?The examined CRCs could be categorized into three subgroups using hierarchical cluster analysis. Tumors in subgroup 1 were characterized by a low frequency of SCNAs and a high frequency of MSI-high status, whereas tumors in subgroups 2 and 3 were closely associated with a high frequency of SCNAs. Tumors in subgroup 1 were preferentially present in the right-sided colon and showed frequent MSI-high status. Subgroup 3 was distinguished by specific alterations, including gains at 1q23-44, 1p11-36, 10q11-26, 10p11-13, 12q24-24, and 13q33-33. In contrast, tumors in subgroup 2 were characterized by copy-neutral LOH at 12p12-13, 1q24-25, and 10q22. In addition, KRAS mutations were more frequently found in subgroup 3 than in subgroup 1. TP53 mutations and intermediate levels of DNA methylation were common alterations in the three subgroups. SCNAs contributed to sporadic CRC, and there were three subgroups based on SCNAs that played a different role in driving the development of this disease.

| S-EPMC5814737 | biostudies-literature

Detection of somatic copy number alterations in cancer using targeted exome capture sequencing.

Project description:The research community at large is expending considerable resources to sequence the coding region of the genomes of tumors and other human diseases using targeted exome capture (i.e., "whole exome sequencing"). The primary goal of targeted exome sequencing is to identify nonsynonymous mutations that potentially have functional consequences. Here, we demonstrate that whole-exome sequencing data can also be analyzed for comprehensively monitoring somatic copy number alterations (CNAs) by benchmarking the technique against conventional array CGH. A series of 17 matched tumor and normal tissues from patients with metastatic castrate-resistant prostate cancer was used for this assessment. We show that targeted exome sequencing reliably identifies CNAs that are common in advanced prostate cancer, such as androgen receptor (AR) gain and PTEN loss. Taken together, these data suggest that targeted exome sequencing data can be effectively leveraged for the detection of somatic CNAs in cancer.

| S-EPMC3223606 | biostudies-literature

A genome-wide screen for copy number alterations in Aicardi syndrome.

Project description:Aicardi syndrome is a severe neurodevelopmental disorder that affects females or rarely males with a 47,XXY karyotype. Therefore, it is thought to be caused by heterozygous defects in an essential X-linked gene or by defects in an autosomal gene with sex-limited expression. Because all reported cases are sporadic with one exception, traditional linkage analysis to identify the mutant gene is not possible, and the de novo mutation rate must be high. As an alternative approach to localize the mutant gene, we screened the DNA of 38 girls with Aicardi syndrome by high-resolution, genome-wide array comparative genomic hybridization for copy number gains and losses. We found 110 copy number variants (CNVs), 97 of which are known, presumably polymorphic, CNVs; 8 have been seen before in unrelated studies in unaffected individuals. Four previously unseen CNVs on autosomes were each inherited from a healthy parent. One subject with Aicardi syndrome had a de novo loss of X-linked copy number in a region without known genes. Detailed analysis of this and flanking regions did not reveal CNVs or mutations in annotated genes in other affected subjects. We conclude that, in this study population of 38 subjects, Aicardi syndrome is not caused by CNVs detectable with the high-resolution array platform that was used.

| S-EPMC3640635 | biostudies-literature

Genome-wide copy number alterations in subtypes of invasive breast cancers in young white and African American women.

Project description:Genomic copy number alterations (CNA) are common in breast cancer. Identifying characteristic CNAs associated with specific breast cancer subtypes is a critical step in defining potential mechanisms of disease initiation and progression. We used genome-wide array comparative genomic hybridization to identify distinctive CNAs in breast cancer subtypes from 259 young (diagnosed with breast cancer at <55 years) African American (AA) and Caucasian American (CA) women originally enrolled in a larger population-based study. We compared the average frequency of CNAs across the whole genome for each breast tumor subtype and found that estrogen receptor (ER)-negative tumors had a higher average frequency of genome-wide gain (P < 0.0001) and loss (P = 0.02) compared to ER-positive tumors. Triple-negative (TN) tumors had a higher average frequency of genome-wide gain (P < 0.0001) and loss (P = 0.003) than non-TN tumors. No significant difference in CNA frequency was observed between HER2-positive and -negative tumors. We also identified previously unreported recurrent CNAs (frequency >40%) for TN breast tumors at 10q, 11p, 11q, 16q, 20p, and 20q. In addition, we report CNAs that differ in frequency between TN breast tumors of AA and CA women. This is of particular relevance because TN breast cancer is associated with higher mortality and young AA women have higher rates of TN breast tumors compared to CA women. These data support the possibility that higher overall frequency of genomic alteration events as well as specific focal CNAs in TN breast tumors might contribute in part to the poor breast cancer prognosis for young AA women.

| S-EPMC3224104 | biostudies-literature

Molecular profiling and comprehensive genome-wide analysis of somatic copy number alterations in gastric intramucosal neoplasias based on microsatellite status.

Project description:BACKGROUND:We attempted to identify the molecular profiles of gastric intramucosal neoplasia (IMN; low-grade dysplasia, LGD; high-grade dysplasia, HGD; intramucosal cancer, IMC) by assessing somatic copy number alterations (SCNAs) stratified by microsatellite status (microsatellite stable, MSS; microsatellite instable, MSI). Thus, microsatellite status was determined in 84 tumors with MSS status and 16 tumors with MSI status. METHODS:One hundred differentiated type IMNs were examined using SCNAs. In addition, genetic mutations (KRAS, BRAF, PIK3CA, and TP53) and DNA methylation status (low, intermediate and high) were also analyzed. Finally, we attempted to identify molecular profiles using a hierarchical clustering analysis. RESULTS:Three patterns could be categorized according to SCNAs in IMNs with the MSS phenotype: subgroups 1 and 2 showing a high frequency of SCNAs, and subgroup 3 displaying a low frequency of SCNAs (subgroup 1 > 2 > 3 for SCNA). Subgroup 1 could be distinguished from subgroup 2 by the numbers of total SCNAs (gains and losses) and SCN gains (subgroup 1 > 2). The SCNA pattern of LGD was different from that of HGD and IMC. Moreover, IMNs with the MSI phenotype could be categorized into two subtypes: high frequency of SCNAs and low frequency of SCNAs. Genetic mutations and DNA methylation status did not differ among subgroups in IMNs. CONCLUSION:Molecular profiles stratified by SCNAs based on microsatellite status may be useful for elucidation of the mechanisms of early gastric carcinogenesis.

| S-EPMC6097076 | biostudies-literature

Genome-wide somatic copy number alterations in low-grade PanINs and IPMNs from individuals with a family history of pancreatic cancer.

Project description:Characterizing the earliest chromosomal alterations of pancreatic precursor neoplasms from individuals with a familial aggregation of pancreatic cancer may provide clues as to the loci of pancreatic cancer susceptibility genes.We used Illumina 370/660K SNP arrays to conduct genome-wide copy number analysis in 60 benign neoplasms [58 mostly low-grade pancreatic intraepithelial neoplasias (PanIN) and intraductal papillary mucinous neoplasms (IPMN) and two pancreatic neuroendocrine tumors (PNET)] and matched normal tissues from 16 individuals with a family history of pancreatic cancer. PanINs and IPMNs were analyzed for KRAS codon 12/13 mutations.Of 40 benign neoplasms with adequate SNP calls and allele ratios, somatic chromosomal copy number changes were identifiable in only nine lesions, including eight of the 38 PanIN/IPMNs (two of which had identical alterations) and one of the two PNETs. Only two precursor lesions had more than one somatic copy number alteration. In contrast, the overwhelming majority (?95%) of PanINs harbored KRAS mutations. The chromosomal alterations identified included nine chromosomal arms affected by chromosomal loss and two by chromosomal gain. Copy number loss spanning 9p21.3 was identified in three precursor lesions; two precursors had chromosomal losses affecting 6q and 17p.Low- and intermediate-grade PanINs and IPMNs from patients with a family history of pancreatic cancer harbor few if any somatic chromosomal alterations. The absence of a locus of recurrent chromosomal loss in most low-grade pancreatic cancer precursor lesions supports the hypothesis that there is no one tumor suppressor gene locus consistently involved in initiating familial pancreatic neoplasia.

| S-EPMC3629843 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data