Project description:Structural rearrangements form a major class of somatic variation in cancer genomes. Local chromosome shattering, termed chromothripsis, is a mechanism proposed to be the cause of clustered chromosomal rearrangements and was recently described to occur in a small percentage of tumors. The significance of these clusters for tumor development or metastatic spread is largely unclear. We used genome-wide long mate-pair sequencing and SNP array profiling to reveal that chromothripsis is a widespread phenomenon in primary colorectal cancer and metastases. We find large and small chromothripsis events in nearly every colorectal tumor sample and show that several breakpoints of chromothripsis clusters and isolated rearrangements affect cancer genes, including NOTCH2, EXO1 and MLL3. We complemented the structural variation studies by sequencing the coding regions of a cancer exome in all colorectal tumor samples and found somatic mutations in 24 genes, including APC, KRAS, SMAD4 and PIK3CA. A pairwise comparison of somatic variations in primary and metastatic samples indicated that in many chromothripsis clusters, isolated rearrangements and point mutations are exclusively present in either the primary tumor or the metastasis and may affect cancer genes in a lesion-specific manner. We conclude that chromothripsis is a prevalent mechanism driving structural rearrangements in colorectal cancer and show that a complex interplay between point mutations, simple copy number changes and chromothripsis events drive colorectal tumor development and metastasis. We analyzed 16 tissue samples from four patients. For each patient we analyzed the DNA of a primary colon tumor sample, a normal colon tissue sample, a metastatic liver tumor sample and a normal liver tissue sample. The normal colon and normal liver samples serve as a control for the primary and metastatic tumor samples.

2011-10-11 | E-GEOD-32711 | biostudies-arrayexpress

Crystal structure of Homo sapiens kynureninase.

Project description: Not available

| S-EPMC2531291 | biostudies-literature

Whole-exome sequencing (WES) of single glands from opposite side of two colorectal tumors and WES of colorectal cancer xenografts derived from single cell culture to study tumor growth dynamics

Project description:Single Gland Whole-exome sequencing: building on our prior description of multi-region WES of colorectal tumors and targeted single gland sequencing (E-MTAB-2247), we performed WES of multiple single glands from different sides (right: A and left: B) of two tumors in this study (tumor O and U) on the illumina platform using the Agilent SureSelect 2.0 or illumina Nextera Rapid Capture Exome kit (SureSelect or NRCE, as indicated in the naming of fastq files). Colorectal Cancer Xenograft Whole-exome sequencing: The HCT116 and LoVo Mismatch-Repair-deficient colorectal adenocarcinoma cell lines were obtained from the ATCC and cultured under standard conditions. For both cell lines, a single âfoundingâ cell was cloned and expanded in vitro to ~6M cells. Two aliquots of ~1M cells were subcutaneously injected into opposite flanks (right and left) of a nude mouse and tumors allowed to reach a size of ~1B cells (1cm3) before the animal was sacrificed. Tumor tissue was collected separately from the right and left lesions and DNA was extracted for WES using the illumina TruSeq Exome kit or Nextera Rapid Capture Exome expanded Kits (Truseq or NRCEe), as was DNA from the first passage population (a polyclonal tissue culture for HCT116 and a polyclonal xenograft sample for LoVo), which were employed as a control to study mutation accumulation in culture and post xenotransplantation.

2017-05-01 | E-MTAB-5547 | biostudies-arrayexpress

Homo sapiens whole blood.

Project description:RNA extracted at 240min. Samples are rRNA depleted. Expression measurement of Homo sapiens genes.

2019-07-31 | GSE114179 | GEO