Project description:Solid tumors were histopathologically categorized into carcinomas and sarcomas and analyzed based on structural variations specific to each group. To investigate this, we utilized whole genome sequencing (WGS) data from dogs with solid tumors, including carcinomas and sarcomas. Structural variations, which induce extensive base changes, significantly impact tumor development. Through our analysis, we identified 146,847 structural variations within the solid tumor data. By comparing each solid tumor group, we identified both common genes affecting tumors across groups and differential genes unique to carcinomas and sarcomas. This finding suggests that understanding the specific genetic alterations associated with each tumor type can enhance the accuracy of diagnosis, inform treatment strategies, and improve prognostic assessments.
Project description:Somatic genome rearrangements are thought to play important roles in cancer development. We optimized a long span paired-end-tag (PET) sequencing approach using 10 Kb genomic DNA inserts to study human genome structural variations (SVs). The use of 10 Kb insert size allows the identification of breakpoints within repetitive or homology containing regions of a few Kb in size and results in a higher physical coverage compared to small insert libraries with the same sequencing effort. We have applied this approach to comprehensively characterize the SVs of 15 cancer and 2 non-cancer genomes and used a filtering approach to strongly enrich for somatic SVs in the cancer genomes. Our analyses revealed that most inversions, deletions, and insertions are germline SVs, whereas tandem duplications, unpaired inversions, inter-chromosomal translocations, and complex rearrangements are overrepresented among somatic rearrangements in cancer genomes. We demonstrate that the quantitative and connective nature of DNA-PET data is precise in delineating the genealogy of complex rearrangement events, we observe signatures which are compatible with breakage-fusion-bridge cycles, and discover that large duplications are among the initial rearrangements that trigger genome instability for extensive amplification in epithelial cancers. Structural variations of 15 human cancer samples and 2 human normal samples were identified by long span paired-end sequencing
Project description:We identified genomic structural alterations of six patients with signs of neurodevelopmental disorder (NDDs) that harbour chromosomal rearrangements using large-insert paired-end tag sequencing (DNA-PET). This technique allowed the refinement of chromosomal breakpoints and lead to the identification of seven disrupted genes (GNAQ, RBFOX3, UNC5D, TMEM47, NCAPG2, GTDC1 and XIAP). For one patient we filtered the entire panel of structural variations (SVs) with his parents and identified a unique SV that disrupted a single gene: GTDC1. We then validated the functional consequences of the chromosomal breakpoint disruption of GTDC1 by using patient-derived iPSCs. By differentiating these cells into neural progenitor cells (NPCs) and neurons, we interrogated the disease process at the cellular level and observed defects in the proliferation and glycosylation status of NPCs and also defects in neuronal maturation and function. We compared these results with GTDC1-deficient wild-type human NPCs and neurons, and observed similar phenotypic features as in the patient-derived cells which confirm that GTDC1 is involved in the patient’s phenotype. We show here that the combination of genomic screening with iPSCs technology provides a mechanistic insight into possible contributory effects of candidate genes implicated in NDDs and for personalized medicine. Structural variations were identified by long insert DNA paired-end tag (DNA-PET) sequencing, a mate-pair sequencing approach.
Project description:Structural variations (SVs) contribute significantly to the variability of the human genome and extensive genomic rearrangements are a hallmark of cancer. Genomic DNA paired-end-tag (DNA-PET) sequencing is an attractive approach to identify genomic SVs. The current application of PET sequencing with short insert size DNA is insufficient for the comprehensive mapping of SVs in low complexity and repeat-rich genomic regions. We have developed a robust procedure to generate PET sequencing data using large DNA inserts of 10 - 20 kb for the identification of SVs. We compared the characteristics of the large insert libraries with short insert (1 kb) libraries with the same sequencing depths and costs. Although short insert libraries bear an advantage in identifying small deletions, they do not provide a significantly better breakpoint resolution. Large inserts are superior to short inserts in providing higher physical genome coverage and therefore achieve greater sensitivity for the identification of the different types of SVs, including copy number neutral and complex events. Further, large inserts allow the identification of SVs within repetitive sequences which cannot be spanned by short inserts. Structural variations of three cancer cell lines using short (1 kb) and long (10 kb and 20 kb) insert size DNA fragments
Project description:We used massively parallel DNA sequencing of paired-end ditags (DNA-PET) to identify structural genetic factors associated with disease progression and drug-resistance in representative samples from four CML patients and one CML cell line. The functional consequences of our genetic findings were evaluated in primary CML cells and cell lines, and validated in a larger CML cohort. We discovered a novel intronic deletion that correlated with imatinib-resistance, and was subsequently confirmed to be a polymorphism in normal East-Asian, but not African or Caucasian, populations. We found that the polymorphism favored expression of transcripts lacking a pro-apoptotic domain, which is critical for imatinib-induced cell death. A CML cell line containing the polymorphism also exhibited BCR-ABL-independent imatinib-resistance. Structural variations of 5 human CML samples were identified by long span paired-end sequencing
Project description:Glioblastoma multiforme is the most common and aggressive type of brain cancer. Little is known about the complex relationship between genomic and epigenomic as tumour progresses. We present the following base resolution whole genome maps of matched tumour/margin and blood samples from a glioblastoma multiforme patient:<br>* Single nucleotide variations (SNVs), copy number variations (CNVs) and structural variations (SVs) as revealed by DNA sequencing. </br> <br>* 5-methylcytosine and 5-hydroxymethylcytosine levels obtained using (oxidative)bisulfite sequencing. </br> <br>* Transcript levels produced using RNA sequencing.</br> <br>For the three samples with very large bam raw data files ('Blood DNA-seq', 'Margin DNA-seq' and 'Tumour DNA-seq'), bai index files are available from https://www.ebi.ac.uk/arrayexpress/files/E-MTAB-5171/E-MTAB-5171.additional.1.zip