scholarly journals Dissecting Intra-Tumor Heterogeneity by the Analysis of Copy Number Variations in Single Cells: The Neuroblastoma Case Study

2019 ◽  
Vol 20 (4) ◽  
pp. 893 ◽  
Author(s):  
Federica Cariati ◽  
Francesca Borrillo ◽  
Varun Shankar ◽  
Marcella Nunziato ◽  
Valeria D’Argenio ◽  
...  
Keyword(s):  
Cell Lines ◽  
Copy Number ◽  
Tumor Heterogeneity ◽  
Single Cells ◽  
Neuroblastoma Cell ◽  
Copy Number Variants ◽  
Copy Number Variations ◽  
Cellular Heterogeneity ◽  
Genotypic Differences ◽  
Laboratory Protocol

Tumors often show intra-tumor heterogeneity because of genotypic differences between all the cells that compose it and that derive from it. Recent studies have shown significant aspects of neuroblastoma heterogeneity that may affect the diagnostic-therapeutic strategy. Therefore, we developed a laboratory protocol, based on the combination of the advanced dielectrophoresis-based array technology and next-generation sequencing to identify and sort single cells individually and carry out their copy number variants analysis. The aim was to evaluate the cellular heterogeneity, avoiding overestimation or underestimation errors, due to a bulk analysis of the sample. We tested the above-mentioned protocol on two neuroblastoma cell lines, SK-N-BE(2)-C and IMR-32. The presence of several gain or loss chromosomal regions, in both cell lines, shows a high heterogeneity of the copy number variants status of the single tumor cells, even if they belong to an immortalized cell line. This finding confirms that each cell can potentially accumulate different alterations that can modulate its behavior. The laboratory protocol proposed herein provides a tool able to identify prevalent behaviors, and at the same time highlights the presence of particular clusters that deviate from them. Finally, it could be applicable to many other types of cancer.

scholarly journals Genotype-Phenotype correlation in Dravet Syndrome with SCN1A mutation increase efficiency of molecular diagnosis

2012 ◽  
Vol 18 (2) ◽  
pp. 60-62
Author(s):  
MC Gonsales ◽  
P Preto ◽  
MA Montenegro ◽  
MM Guerreiro ◽  
I Lopes-Cendes
Keyword(s):  
Protein Function ◽  
Copy Number ◽  
Mutation Screening ◽  
Copy Number Variants ◽  
Febrile Seizures ◽  
Copy Number Variations ◽  
Dravet Syndrome ◽  
Missense Mutations ◽  
The Impact ◽  
Doose Syndrome

OBJECTIVES: The purpose of this study was to advance the knowledge on the clinical use of SCN1A testing for severe epilepsies within the spectrum of generalized epilepsy with febrile seizures plus by performing genetic screening in patients with Dravet and Doose syndromes and establishing genotype-phenotype correlations. METHODS: Mutation screening in SCN1A was performed in 15 patients with Dravet syndrome and 13 with Doose syndrome. Eight prediction algorithms were used to analyze the impact of the mutations in putative protein function. Furthermore, all SCN1A mutations previously published were compiled and analyzed. In addition, Multiplex Ligation-Dependent Probe Amplification (MLPA) technique was used to detect possible copy number variations within SCN1A. RESULTS: Twelve mutations were identified in patients with Dravet syndrome, while patients with Doose syndrome showed no mutations. Our results show that the most common type of mutation found is missense, and that they are mostly located in the pore region and the N- and C-terminal of the protein. No copy number variants in SCN1A were identified in our cohort. CONCLUSIONS: SCN1A testing is clinically useful for patients with Dravet syndrome, but not for those with Doose syndrome, since both syndromes do not seem to share the same genetic basis. Our results indicate that indeed missense mutations can cause severe phenotypes depending on its location and the type of amino-acid substitution. Moreover, our strategy for predicting deleterious effect of mutations using multiple computation algorithms was efficient for most of the mutations identified.

scholarly journals Evolution and lineage dynamics of a transmissible cancer in Tasmanian devils

PLoS Biology ◽  
2020 ◽  
Vol 18 (11) ◽  
pp. e3000926 ◽  
Author(s):  
Young Mi Kwon ◽  
Kevin Gori ◽  
Naomi Park ◽  
Nicole Potts ◽  
Kate Swift ◽  
...  
Keyword(s):  
Positive Selection ◽  
Cancer Cells ◽  
Cell Lines ◽  
Copy Number ◽  
Convergent Evolution ◽  
Evolutionary History ◽  
Genome Instability ◽  
Copy Number Variants ◽  
Tasmanian Devil ◽  
Transmissible Cancer

Devil facial tumour 1 (DFT1) is a transmissible cancer clone endangering the Tasmanian devil. The expansion of DFT1 across Tasmania has been documented, but little is known of its evolutionary history. We analysed genomes of 648 DFT1 tumours collected throughout the disease range between 2003 and 2018. DFT1 diverged early into five clades, three spreading widely and two failing to persist. One clade has replaced others at several sites, and rates of DFT1 coinfection are high. DFT1 gradually accumulates copy number variants (CNVs), and its telomere lengths are short but constant. Recurrent CNVs reveal genes under positive selection, sites of genome instability, and repeated loss of a small derived chromosome. Cultured DFT1 cell lines have increased CNV frequency and undergo highly reproducible convergent evolution. Overall, DFT1 is a remarkably stable lineage whose genome illustrates how cancer cells adapt to diverse environments and persist in a parasitic niche.

Application of Restriction Site-Associated DNA Sequencing (RAD-Seq) for Copy Number Variation and Triploidy Detection in Human

2021 ◽  
pp. 1-8
Author(s):  
Jian-Chun He ◽  
Shao-Ying Li ◽  
Wen-Zhi He ◽  
Jia-Jia Xian ◽  
Xiao-Yan Ma ◽  
...  
Keyword(s):  
Dna Sequencing ◽  
Cell Lines ◽  
Genome Sequencing ◽  
Copy Number ◽  
Restriction Site ◽  
Chromosomal Abnormalities ◽  
Copy Number Variations ◽  
Str Analysis ◽  
Tissue Samples ◽  
Low Pass

At present, low-pass whole-genome sequencing (WGS) is frequently used in clinical research and in the screening of copy number variations (CNVs). However, there are still some challenges in the detection of triploids. Restriction site-associated DNA sequencing (RAD-Seq) technology is a reduced-representation genome sequencing technology developed based on next-generation sequencing. Here, we verified whether RAD-Seq could be employed to detect CNVs and triploids. In this study, genomic DNA of 11 samples was extracted employing a routine method and used to build libraries. Five cell lines of known karyotypes and 6 triploid abortion tissue samples were included for RAD-Seq testing. The triploid samples were confirmed by STR analysis and also tested by low-pass WGS. The accuracy and efficiency of detecting CNVs and triploids by RAD-Seq were then assessed, compared with low-pass WGS. In our results, RAD-Seq detected 11 out of 11 (100%) chromosomal abnormalities, including 4 deletions and 1 aneuploidy in the purchased cell lines and all triploid samples. By contrast, these triploids were missed by low-pass WGS. Furthermore, RAD-Seq showed a higher resolution and more accurate allele frequency in the detection of triploids than low-pass WGS. Our study shows that, compared with low-pass WGS, RAD-Seq has relatively higher accuracy in CNV detection at a similar cost and is capable of identifying triploids. Therefore, the application of this technique in medical genetics has a significant potential value.

scholarly journals Genome-wide characterization of copy number variations in diffuse large B-cell lymphoma with implications in targeted therapy

2019 ◽  
Vol 2 (4) ◽  
pp. 246-258
Author(s):  
Prashanthi Dharanipragada ◽  
Nita Parekh
Keyword(s):  
B Cell ◽  
Cell Lines ◽  
Copy Number ◽  
Cell Lymphoma ◽  
B Cell Lymphoma ◽  
Copy Number Variations ◽  
Model Systems ◽  
Significant Heterogeneity ◽  
Large B Cell Lymphoma ◽  
Large B Cell

Abstract Diffuse large B-cell lymphoma (DLBCL) is the aggressive form of haematological malignancies with relapse/refractory in ~ 40% of cases. It mostly develops due to accumulation of various genetic and epigenetic variations that contribute to its aggressiveness. Though large-scale structural alterations have been reported in DLBCL, their functional role in pathogenesis and as potential targets for therapy is not yet well understood. In this study we performed detection and analysis of copy number variations (CNVs) in 11 human DLBCL cell lines (4 activated B-cell–like [ABC] and 7 germinal-centre B-cell–like [GCB]), that serve as model systems for DLBCL cancer cell biology. Significant heterogeneity observed in CNV profiles of these cell lines and poor prognosis associated with ABC subtype indicates the importance of individualized screening for diagnostic and prognostic targets. Functional analysis of key cancer genes exhibiting copy alterations across the cell lines revealed activation/disruption of ten potentially targetable immuno-oncogenic pathways. Genome guided in silico therapy that putatively target these pathways is elucidated. Based on our analysis, five CNV-genes associated with worst survival prognosis are proposed as potential prognostic markers of DLBCL.

scholarly journals RBV: Read balance validator, a tool for prioritising copy number variations in germline conditions

2018 ◽  
Author(s):  
Whitney Whitford ◽  
Klaus Lehnert ◽  
Russell G. Snell ◽  
Jessie C. Jacobsen
Keyword(s):  
Copy Number ◽  
High Throughput Sequencing ◽  
Sequence Data ◽  
Relative Proportion ◽  
Copy Number Variants ◽  
Read Depth ◽  
Copy Number Variations ◽  
Single Nucleotide Variants ◽  
Software Packages ◽  
Bioinformatic Tool

AbstractBackgroundThe popularisation and decreased cost of genome resequencing has resulted in an increased use in molecular diagnostics. While there are a number of established and high quality bioinfomatic tools for identifying small genetic variants including single nucleotide variants and indels, currently there is no established standard for the detection of copy number variants (CNVs) from sequence data. The requirement for CNV detection from high throughput sequencing has resulted in the development of a large number of software packages. These tools typically utilise the sequence data characteristics: read depth, split reads, read pairs, and assembly-based techniques. However the additional source of information from read balance, defined as relative proportion of reads of each allele at each position, has been underutilised in the existing applications.ResultsWe present Read Balance Validator (RBV), a bioinformatic tool which uses read balance for prioritisation and validation of putative CNVs. The software simultaneously interrogates nominated regions for the presence of deletions or multiplications, and can differentiate larger CNVs from diploid regions. Additionally, the utility of RBV to test for inheritance of CNVs is demonstrated in this report.ConclusionsRBV is a CNV validation and prioritisation bioinformatic tool for both genome and exome sequencing available as a python package from https://github.com/whitneywhitford/RBV

scholarly journals Predictive impact of rare genomic copy number variations in siblings of individuals with autism spectrum disorders

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
L. D’Abate ◽  
S. Walker ◽  
R. K. C. Yuen ◽  
K. Tammimies ◽  
J. A. Buchanan ◽  
...  
Keyword(s):  
Autism Spectrum Disorders ◽  
Copy Number ◽  
Copy Number Variants ◽  
Autism Spectrum ◽  
Copy Number Variations ◽  
Recurrence Prediction ◽  
Common Genetic Variants ◽  
Spectrum Disorders ◽  
Atypical Development ◽  
Research Consortium

AbstractIdentification of genetic biomarkers associated with autism spectrum disorders (ASDs) could improve recurrence prediction for families with a child with ASD. Here, we describe clinical microarray findings for 253 longitudinally phenotyped ASD families from the Baby Siblings Research Consortium (BSRC), encompassing 288 infant siblings. By age 3, 103 siblings (35.8%) were diagnosed with ASD and 54 (18.8%) were developing atypically. Thirteen siblings have copy number variants (CNVs) involving ASD-relevant genes: 6 with ASD, 5 atypically developing, and 2 typically developing. Within these families, an ASD-related CNV in a sibling has a positive predictive value (PPV) for ASD or atypical development of 0.83; the Simons Simplex Collection of ASD families shows similar PPVs. Polygenic risk analyses suggest that common genetic variants may also contribute to ASD. CNV findings would have been pre-symptomatically predictive of ASD or atypical development in 11 (7%) of the 157 BSRC siblings who were eventually diagnosed clinically.

A Study from Turkey: Identification of Copy Number Variants in Children and Adolescents with Autism Spectrum Disorder

2021 ◽  
Author(s):  
Ahmet Özaslan ◽  
Gülsüm Kayhan ◽  
Elvan İşeri ◽  
Mehmet Ali Ergün ◽  
Esra Güney ◽  
...  
Keyword(s):  
Copy Number ◽  
Diagnostic Yield ◽  
Venous Blood ◽  
Copy Number Variants ◽  
Clinical Importance ◽  
Turkish Population ◽  
Autism Spectrum ◽  
Copy Number Variations ◽  
Turkish Children ◽  
Children With Asd

Abstract Recent studies suggest that copy number variations (CNVs) play a significant role in the aetiology of ASD. This study aims to investigate CNVs, which are thought to be an important factor in ASD etiology. In addition it was aimed to specify the clinical usefulness of chromosomal microarrays (CMA) in the examination of ASD patients in Turkish population. Of 47 children (60.34±25.60 months; 82.9% boys) with ASD were constructed the sample. The karyotype structure of all participants was found to be normal using conventional cytogenetic methods. DNA obtained from the venous blood samples of the participants was evaluated using SurePrint G3 ISCA V2 CGH 8x60K Array (Agilent Technologies Santa Clara, CA, USA). We have identified 8 CNVs, ranging in size from 55 kb to 6.5 Mb in 7 (5 boys) of 47 children with ASD of the 4 of 8 CNVs were classified as pathogenic, which were 9p24.3p24.2 deletion in 3 Mb size, 15q11-q13 duplication in 6.5 Mb size, 16p11.2 deletion in 598 kb size and 22q13.3 deletion in 55 kb size. According to results has been demonstrated that diagnostic yield of CMA in Turkish children with ASD was 8.5%. Our results indicate that CNVs contribute a part to the genetic aetiology of Turkish children with ASD. In accordance with the literature, these results emphasize the clinical importance of CMA to investigate the aetiology of ASD.

scholarly journals Common copy number variations in fifty radiosensitive cell lines

Genomics ◽  
2012 ◽  
Vol 99 (2) ◽  
pp. 96-100 ◽  
Author(s):  
Xinmin Li ◽  
Jian Zhou ◽  
Shareef A. Nahas ◽  
Haolei Wan ◽  
Hailiang Hu ◽  
...  
Keyword(s):  
Cell Lines ◽  
Copy Number ◽  
Copy Number Variations
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