Chromothripsis drives DNA amplification in cancer cells developing drug resistance
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA490379 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Chromothripsis drives DNA amplification in cancer cells developing drug resistance
| PRJNA490891 | ENA
Project description:Gene amplification leading to increased oncogene expression or anticancer drug resistance is a frequent event in cancer. Cytogenetic, genomic, and transcriptomic analyses were used to determine the initiating events of gene amplification in a tunable cell culture system developing resistance to chemotherapy. Chromosome shattering (chromothripsis) was found to be a major resistance driver through the production of extra-chromosomal double minutes either directly or subsequent to formation of a homogenous staining region (HSR). Formation and maintenance of double minutes were enhanced by PARP and DNA-PK activities. Double minutes were found to be highly dynamic, undergoing structural evolution to produce increased drug tolerance or re-integration into ectopic chromosomes under conditions of DNA damage. Genome rearrangement profiles produced through acquired drug resistance are similar to human cancer examples with oncogene amplification. Thus, chromothripsis is a driver of genome evolution that enables rapid acquisition of tolerance to altered growth conditions.
2020-09-14 | GSE119979 | GEO
Project description:Gene amplification leading to increased oncogene expression or anticancer drug resistance is a frequent event in cancer. Cytogenetic, genomic, and transcriptomic analyses were used to determine the initiating events of gene amplification in a tunable cell culture system developing resistance to chemotherapy. Chromosome shattering (chromothripsis) was found to be a major resistance driver through the production of extra-chromosomal double minutes either directly or subsequent to formation of a homogenous staining region (HSR). Formation and maintenance of double minutes were enhanced by PARP and DNA-PK activities. Double minutes were found to be highly dynamic, undergoing structural evolution to produce increased drug tolerance or re-integration into ectopic chromosomes under conditions of DNA damage. Genome rearrangement profiles produced through acquired drug resistance are similar to human cancer examples with oncogene amplification. Thus, chromothripsis is a driver of genome evolution that enables rapid acquisition of tolerance to altered growth conditions.
2020-09-23 | GSE119825 | GEO
Project description:The mechanisms behind the evolution of complex genomic amplifications in cancer have remained largely unclear. We here identified a type of amplification, termed as “seismic amplificationâ€Â, that is characterized by multiple rearrangements and discontinuous copy number levels. Seismic amplifications occurred in 9.9% (274/2,756) of cases across 38 cancer types and were associated with massively increased copy numbers and elevated oncogene expression. Reconstruction of the development of seismic amplification revealed a stepwise evolution, starting with a chromothripsis event, followed by formation of circular extrachromosomal DNA that subsequently underwent repetitive rounds of circular recombination. The resulting amplicons persisted as extrachromosomal DNA circles or had reintegrated into the genome in overt tumors. Together, our data indicate that the sequential occurrence of chromothripsis and circular recombination drives oncogene amplification and over-expression in a substantial fraction of human malignancies.
| EGAS00001005424 | EGA
Project description:Chromothripsis followed by circular recombination drives oncogene amplification in human cancer
| PRJEB45367 | ENA
Project description:Focal chromosomal amplification contributes to the initiation of cancer by mediating overexpression of oncogenes1-3, and to the development of cancer therapy resistance by increasing the expression of genes whose action diminishes the efficacy of anti-cancer drugs. Here we used whole-genome sequencing of clonal cell isolates that developed chemotherapeutic resistance to show that chromothripsis is a major driver of circular extrachromosomal DNA (ecDNA) amplification (also known as double minutes) through mechanisms that depend on poly(ADP-ribose) polymerases (PARP) and the catalytic subunit of DNA-dependent protein kinase (DNA-PKcs). Longitudinal analyses revealed that a further increase in drug tolerance is achieved by structural evolution of ecDNAs through additional rounds of chromothripsis. In situ Hi-C sequencing showed that ecDNAs preferentially tether near chromosome ends, where they re-integrate when DNA damage is present. Intrachromosomal amplifications that formed initially under low-level drug selection underwent continuing breakage-fusion-bridge cycles, generating amplicons more than 100 megabases in length that became trapped within interphase bridges and then shattered, thereby producing micronuclei whose encapsulated ecDNAs are substrates for chromothripsis. We identified similar genome rearrangement profiles linked to localized gene amplification in human cancers with acquired drug resistance or oncogene amplifications. We propose that chromothripsis is a primary mechanism that accelerates genomic DNA rearrangement and amplification into ecDNA and enables rapid acquisition of tolerance to altered growth conditions.
| S-EPMC7116864 | biostudies-literature
Project description:Focal chromosomal amplification contributes to the initiation of cancer by mediating overexpression of oncogenes1-3, and to the development of cancer therapy resistance by increasing the expression of genes whose action diminishes the efficacy of anti-cancer drugs. Here we used whole-genome sequencing of clonal cell isolates that developed chemotherapeutic resistance to show that chromothripsis is a major driver of circular extrachromosomal DNA (ecDNA) amplification (also known as double minutes) through mechanisms that depend on poly(ADP-ribose) polymerases (PARP) and the catalytic subunit of DNA-dependent protein kinase (DNA-PKcs). Longitudinal analyses revealed that a further increase in drug tolerance is achieved by structural evolution of ecDNAs through additional rounds of chromothripsis. In situ Hi-C sequencing showed that ecDNAs preferentially tether near chromosome ends, where they re-integrate when DNA damage is present. Intrachromosomal amplifications that formed initially under low-level drug selection underwent continuing breakage-fusion-bridge cycles, generating amplicons more than 100 megabases in length that became trapped within interphase bridges and then shattered, thereby producing micronuclei whose encapsulated ecDNAs are substrates for chromothripsis. We identified similar genome rearrangement profiles linked to localized gene amplification in human cancers with acquired drug resistance or oncogene amplifications. We propose that chromothripsis is a primary mechanism that accelerates genomic DNA rearrangement and amplification into ecDNA and enables rapid acquisition of tolerance to altered growth conditions.
| S-EPMC7933129 | biostudies-literature
Project description:Acquired resistance to MEK1/2 inhibitors can arise through amplification of BRAFV600E or KRASG13D to reinstate ERK1/2 signalling. Here we show that BRAFV600E amplification and selumetinib resistance are fully reversible following drug withdrawal. Resistant cells with BRAFV600E amplification become addicted to selumetinib to maintain a precise level of ERK1/2 signalling (2-3% of total ERK1/2 active, here quantified by mass spectrometry), that is optimal for cell survival and proliferation. The magnitude of ERK1/2 activation following selumetinib withdrawal (~20% active) drives a p57KIP2-dependent G1 cell cycle arrest and senescence or expression of NOXA and cell death, which selects against those cells with amplified BRAFV600E. ERK1/2-dependent p57KIP2 expression is required for loss of BRAFV600E amplification and determines the rate of reversal of selumetinib resistance. Furthermore, growth of selumetinib-resistant cells with BRAFV600E amplification as tumour xenografts is inhibited in mice that do not receive selumetinib. Thus, BRAFV600E amplification confers a selective disadvantage during drug withdrawal, providing a rationale for intermittent dosing to forestall resistance. In striking contrast, selumetinib resistance driven by KRASG13D amplification is not reversible. In these cells ERK1/2 reactivation does not inhibit proliferation but drives a ZEB1-dependent epithelial-to-mesenchymal transition that increases cell motility and promotes resistance to traditional chemotherapy agents arguing strongly against the use of ‘drug holidays’ in cases of KRASG13D amplification.
2019-03-11 | GSE120993 | GEO
Project description:ROS amplification drives mouse spermatogonial stem cell self-renewal
| PRJNA415605 | ENA