Project description:Chromosome segregation errors have been linked to DNA damage and genomic rearrangements. Accumulating evidence has shown that catastrophic genomic rearrangements, like chromothripsis, can result from lagging chromosomes undergoing aberrant DNA replication and DNA damage in micronuclei. Detailed characterization of genomic rearrangements resulting from DNA damage in micronuclei has been hampered because of difficulties in culturing daughter cells with DNA damage. Here, we employ a method by which a specific single chromosome is trapped in a micronucleus, followed by transfer to an acceptor cell. Next, stably propagating clonal cell lines with an extra chromosome were established and analyzed by copy number profiling and whole genome sequencing. While non-transformed, p53 proficient and telomerase-immortalized RPE1 cells showed a stable genome following addition of the transferred chromosome, we observed frequent de novo genomic rearrangements in cells derived from the HCT116 colorectal cancer cell line after chromosome transfer. The de novo rearrangements varied from simple deletions and duplications to complex rearrangements. Phase-informative SNPs revealed that the rearrangements specifically occurred on the transferred chromosome. We found that the complex rearrangements recapitulated all features of chromothripsis, including massive oscillation between two copy number states, localization to a single chromosome, random joining of chromosome fragments and non-homologous or micro-homologous repair. We describe an approach that enables the isolation of clonal cell lines with genomic rearrangements and chromothripsis on a specific chromosome in p53 proficient cells. The procedure enables further investigation of the exact mechanism leading to chromothripsis and the analysis of its consequences for cell survival (viability) and cancer development.
Project description:Chromosome segregation errors have been linked to DNA damage and genomic rearrangements. Accumulating evidence has shown that catastrophic genomic rearrangements, like chromothripsis, can result from lagging chromosomes undergoing aberrant DNA replication and DNA damage in micronuclei. Detailed characterization of genomic rearrangements resulting from DNA damage in micronuclei has been hampered because of difficulties in culturing daughter cells with DNA damage. Here, we employ a method by which a specific single chromosome is trapped in a micronucleus, followed by transfer to an acceptor cell. Next, stably propagating clonal cell lines with an extra chromosome were established and analyzed by copy number profiling and whole genome sequencing. While non-transformed, p53 proficient and telomerase-immortalized RPE1 cells showed a stable genome following addition of the transferred chromosome, we observed frequent de novo genomic rearrangements in cells derived from the HCT116 colorectal cancer cell line after chromosome transfer. The de novo rearrangements varied from simple deletions and duplications to complex rearrangements. Phase-informative SNPs revealed that the rearrangements specifically occurred on the transferred chromosome. We found that the complex rearrangements recapitulated all features of chromothripsis, including massive oscillation between two copy number states, localization to a single chromosome, random joining of chromosome fragments and non-homologous or micro-homologous repair. We describe an approach that enables the isolation of clonal cell lines with genomic rearrangements and chromothripsis on a specific chromosome in p53 proficient cells. The procedure enables further investigation of the exact mechanism leading to chromothripsis and the analysis of its consequences for cell survival (viability) and cancer development.
Project description:Chromosome segregation errors have been linked to DNA damage and genomic rearrangements. Accumulating evidence has shown that catastrophic genomic rearrangements, like chromothripsis, can result from lagging chromosomes undergoing aberrant DNA replication and DNA damage in micronuclei. Detailed characterization of genomic rearrangements resulting from DNA damage in micronuclei has been hampered because of difficulties in culturing daughter cells with DNA damage. Here, we employ a method by which a specific single chromosome is trapped in a micronucleus, followed by transfer to an acceptor cell. Next, stably propagating clonal cell lines with an extra chromosome were established and analyzed by copy number profiling and whole genome sequencing. While non-transformed, p53 proficient and telomerase-immortalized RPE1 cells showed a stable genome following addition of the transferred chromosome, we observed frequent de novo genomic rearrangements in cells derived from the HCT116 colorectal cancer cell line after chromosome transfer. The de novo rearrangements varied from simple deletions and duplications to complex rearrangements. Phase-informative SNPs revealed that the rearrangements specifically occurred on the transferred chromosome. We found that the complex rearrangements recapitulated all features of chromothripsis, including massive oscillation between two copy number states, localization to a single chromosome, random joining of chromosome fragments and non-homologous or micro-homologous repair. We describe an approach that enables the isolation of clonal cell lines with genomic rearrangements and chromothripsis on a specific chromosome in p53 proficient cells. The procedure enables further investigation of the exact mechanism leading to chromothripsis and the analysis of its consequences for cell survival (viability) and cancer development. We analyzed 38 cell clones, originating from HCT116 or RPE1 cells respectively, with Illumina beadchip arrays to test for unique de novo copy number variants and to determine the chromosome affacted by the CNAs.
Project description:Chromosome segregation errors have been linked to DNA damage and genomic rearrangements. Accumulating evidence has shown that catastrophic genomic rearrangements, like chromothripsis, can result from lagging chromosomes undergoing aberrant DNA replication and DNA damage in micronuclei. Detailed characterization of genomic rearrangements resulting from DNA damage in micronuclei has been hampered because of difficulties in culturing daughter cells with DNA damage. Here, we employ a method by which a specific single chromosome is trapped in a micronucleus, followed by transfer to an acceptor cell. Next, stably propagating clonal cell lines with an extra chromosome were established and analyzed by copy number profiling and whole genome sequencing. While non-transformed, p53 proficient and telomerase-immortalized RPE1 cells showed a stable genome following addition of the transferred chromosome, we observed frequent de novo genomic rearrangements in cells derived from the HCT116 colorectal cancer cell line after chromosome transfer. The de novo rearrangements varied from simple deletions and duplications to complex rearrangements. Phase-informative SNPs revealed that the rearrangements specifically occurred on the transferred chromosome. We found that the complex rearrangements recapitulated all features of chromothripsis, including massive oscillation between two copy number states, localization to a single chromosome, random joining of chromosome fragments and non-homologous or micro-homologous repair. We describe an approach that enables the isolation of clonal cell lines with genomic rearrangements and chromothripsis on a specific chromosome in p53 proficient cells. The procedure enables further investigation of the exact mechanism leading to chromothripsis and the analysis of its consequences for cell survival (viability) and cancer development. We analyzed 38 cell clones, originating from HCT116 or RPE1 cells respectively, with Illumina beadchip arrays to test for unique de novo copy number variants and to determine the chromosome affacted by the CNAs.
Project description:Copy number variations and genomic rearrangements in the CFH-CFHRs region were assessed with a custom-designed high-density 8x15k oligonucleotide CGH arrays spanning the RCA gene cluster region in human chromosome 1q32 (median resolution of 110 bp) (AMADID 040193, Agilent Technologies, Santa Clara, CA). A healthy male donor sample, fully genotyped for that region, was used as hybridization control. Microarray data were extracted and visualized using the Feature Extraction Software v10.7 and Genomic Workbench Standard Edition 7.0 (Agilent Corp, Santa Clara, CA). Copy number altered regions were detected using ADM-2 (set as 5) statistic provided by DNA Analytics, with a minimum number of 5 consecutive probes. Genomic build hg19 was used for the experiment.
Project description:Copy number variations and genomic rearrangements in the CFH-CFHRs region were assessed with a custom-designed high-density 8x15k oligonucleotide CGH arrays spanning the RCA gene cluster region in human chromosome 1q32 (median resolution of 110 bp) (AMADID 040193, Agilent Technologies, Santa Clara, CA). A healthy male donor sample, fully genotyped for that region, was used as hybridization control. Microarray data were extracted and visualized using the Feature Extraction Software v10.7 and Genomic Workbench Standard Edition 7.0 (Agilent Corp, Santa Clara, CA). Copy number altered regions were detected using ADM-2 (set as 5) statistic provided by DNA Analytics, with a minimum number of 5 consecutive probes. Genomic build hg19 was used for the experiment. Only a Sample was analyzed
Project description:In Saccharomyces cerevisiae, Elevated Levels of Aneuploidy and Chromosome Rearrangements are Separable Genome Instability Events Controlled by the Tel1 and Mec1 Kinases Cancer cells often have elevated frequencies of chromosomal aberrations, and it is likely that loss of genome stability is one driving force behind tumorigenesis. Deficiencies in DNA replication, DNA repair, or cell cycle checkpoints can all contribute to increased rates of chromosomal duplications, deletions and translocations. The Saccharomyces cerevisiae proteins Tel1 and Mec1 (homologues of the human ATM and ATR proteins, respectively) are known to participate in the DNA damage response, replication checkpoint, and telomere maintenance pathways and are critical to maintain genome stability. In the absence of induced DNA damage, tel1 mec1 diploid yeast strains exhibit extremely high rates of chromosome aneuploidy. There is a significant bias towards trisomy of chromosomes II, VIII, X, and XII, whereas the smallest chromosomes I and VI are commonly monosomic. tel1 mec1 strains also demonstrate elevated levels of chromosome rearrangements, including translocations as well as interstitial duplications and deletions. Restoring wild-type telomere length with the Cdc13-Est2 fusion protein substantially reduces the amount of chromosome rearrangements in tel1 mec1 strains. This result suggests that most of the rearrangements are initiated by telomere-telomere fusions. However, the telomere defects associated with tel1 mec1 strains do not cause the high rate of aneuploidy, as restoring proper telomere function does not prevent cells from becoming aneuploid. Our data demonstrate that the same mutant genotype can produce both high levels of chromosome rearrangements and high levels of aneuploidy, and these two types of events occur through separate mechanisms.
Project description:Study purpose: to explore the entire spectrum of proteomic and genomic changes (amongst others) involved in diseases and in healthy/control populations. The Study is designed to discover biomarkers, develop and validate diagnostic assays, instruments and therapeutics as well as other medical research. Specifically, researchers may analyze proteins, RNA, DNA copy number changes, including large and small (1,000-100,000 kb) scale rearrangements, transcription profiles, epigenetic modifications, sequence variation, and sequence in both diseased tissue and case-matched germline DNA from Subjects.