C9e61a0b-6ac1-4ef1-8925-d86a796781f0 - samples
Ontology highlight
ABSTRACT:
PROVIDER: EGAD00001015363 | EGA |
REPOSITORIES: EGA
Similar Datasets
Project description:The essential process of DNA replication timing during each cell cycle is highly regulated ensuring the correct duplication of the genome. The extent and importance of alterations in this process during malignant transformation has not been extensively explored. Here, we evaluate the impact of altered replication timing (ART) on cancer evolution by analysing replication-timing sequencing of cancer and normal cell lines and 952 whole-genome sequenced lung and breast tumours. We find 6%-18% of the cancer genome displays ART. Genomic regions with a change from early to late replication exhibit an increased mutation rate and distinct mutational signatures, while regions changing from late to early contain genes with increased expression and present a preponderance of APOBEC3-mediated mutation clusters and associated driver mutations. We demonstrate that ART is a relatively early event during cancer evolution and that ART may have a stronger correlation with mutation acquisition than alterations in chromatin structure.
| EGAS00001007773 | EGA
Project description:This is a genomic analysis of breast cancer metastasis using array based CGH and is part of a large study investigating the patterns and evolution of metastases from breast cancer using autopsy material accumulated over the last 50 years from a single institution. The samples used in the genomic profiling comprise the primary breast tumour and multiple matched metastases from each patient. The data demonstrate both the clonal nature of metastatic progression and the role of clonal evolution during progression. This study comprises six patients who died of metastatic breast cancer. For some patients the breast primary tumour and lymph node metastasis was obtained from previous surgical excision, otherwise material was obtained from a resulting autopsy. Each patient set of samples involves the primary breast tumour and multiple metastases, including from lung, liver, lymph node, adrenal gland, brain etc. DNA was extracted from formalin fixed paraffin embedded (FFPE) tissue blocks and analysed for DNA copy number alterations using an Agilent aCGH platform.
2013-11-11 | E-GEOD-46826 | biostudies-arrayexpress
Project description:The temporal order of DNA replication is modified during differentiation, but when a replication timing program is established and what alterations occur in vivo during embryogenesis are not known. Here we used zebrafish embryos to generate genome-wide, high-resolution replication timing maps throughout development. Unexpectedly, a non-random and defined replication timing program was evident in the rapid cell cycles before the midblastula transition. The majority of the genome undergoes dynamic shifts in replication timing throughout development as the timing program is decompressed, with many abrupt timing changes occurring during lineage specification. Strikingly, the long arm of chromosome 4 undergoes a developmentally regulated switch to late replication, reminiscent of mammalian X chromosome inactivation. This analysis also revealed a strong relationship between early replication and epigenetic marks at enhancers. Collectively, these data reveal the major changes in replication timing that occur during zebrafish embryogenesis, and demonstrate its dynamic regulation during vertebrate development.
2017-04-13 | GSE85713 | GEO
Project description:DNA replication timing alterations in genetic diseases
| PRJNA760942 | ENA
Project description:DNA replication timing alterations in genetic diseases
| PRJNA760943 | ENA
Project description:This SuperSeries is composed of the following subset Series: GSE24770: Heterochronic Evolution Reveals Modular Timing Changes in Budding Yeast Transcriptomes (Mutation Accumulation Lines) GSE24771: Heterochronic Evolution Reveals Modular Timing Changes in Budding Yeast Transcriptomes (Natural Strain Timecourse) Refer to individual Series
2010-10-19 | E-GEOD-24772 | biostudies-arrayexpress
Project description:Circulating tumour cells in women with advanced oestrogen-receptor (ER)-positive/human epidermal growth factor receptor 2 (HER2)-negative breast cancer acquire a HER2-positive subpopulation after multiple courses of therapy. In contrast to HER2-amplified primary breast cancer, which is highly sensitive to HER2-targeted therapy, the clinical significance of acquired HER2 heterogeneity during the evolution of metastatic breast cancer is unknown. Here we analyse circulating tumour cells from 19 women with ER+/HER2- primary tumours, 84% of whom had acquired circulating tumour cells expressing HER2. Cultured circulating tumour cells maintain discrete HER2+ and HER2- subpopulations: HER2+ circulating tumour cells are more proliferative but not addicted to HER2, consistent with activation of multiple signalling pathways; HER2- circulating tumour cells show activation of Notch and DNA damage pathways, exhibiting resistance to cytotoxic chemotherapy, but sensitivity to Notch inhibition. HER2+ and HER2- circulating tumour cells interconvert spontaneously, with cells of one phenotype producing daughters of the opposite within four cell doublings. Although HER2+ and HER2- circulating tumour cells have comparable tumour initiating potential, differential proliferation favours the HER2+ state, while oxidative stress or cytotoxic chemotherapy enhances transition to the HER2- phenotype. Simultaneous treatment with paclitaxel and Notch inhibitors achieves sustained suppression of tumorigenesis in orthotopic circulating tumour cell-derived tumour models. Together, these results point to distinct yet interconverting phenotypes within patient-derived circulating tumour cells, contributing to progression of breast cancer and acquisition of drug resistance.
2016-08-25 | GSE75367 | GEO
Project description:Circulating tumour cells in women with advanced oestrogen-receptor (ER)-positive/human epidermal growth factor receptor 2 (HER2)-negative breast cancer acquire a HER2-positive subpopulation after multiple courses of therapy. In contrast to HER2-amplified primary breast cancer, which is highly sensitive to HER2-targeted therapy, the clinical significance of acquired HER2 heterogeneity during the evolution of metastatic breast cancer is unknown. Here we analyse circulating tumour cells from 19 women with ER+/HER2- primary tumours, 84% of whom had acquired circulating tumour cells expressing HER2. Cultured circulating tumour cells maintain discrete HER2+ and HER2- subpopulations: HER2+ circulating tumour cells are more proliferative but not addicted to HER2, consistent with activation of multiple signalling pathways; HER2- circulating tumour cells show activation of Notch and DNA damage pathways, exhibiting resistance to cytotoxic chemotherapy, but sensitivity to Notch inhibition. HER2+ and HER2- circulating tumour cells interconvert spontaneously, with cells of one phenotype producing daughters of the opposite within four cell doublings. Although HER2+ and HER2- circulating tumour cells have comparable tumour initiating potential, differential proliferation favours the HER2+ state, while oxidative stress or cytotoxic chemotherapy enhances transition to the HER2- phenotype. Simultaneous treatment with paclitaxel and Notch inhibitors achieves sustained suppression of tumorigenesis in orthotopic circulating tumour cell-derived tumour models. Together, these results point to distinct yet interconverting phenotypes within patient-derived circulating tumour cells, contributing to progression of breast cancer and acquisition of drug resistance. Seventy-four single candidate CTCs from two representative ER+/HER2- patients (BRx-42 and BRx-82) and 14 triple negative patients were isolated via micromanipulation and subjected to single-cell RNA-sequencing. Thirteen candidate CTCs expressed PTPRC at a level higher than 10 reads-per-million, so were deemed potential White Blood Cells and therefore dropped from further consideration. Expression profiles of CTCs expressing ERBB2 at a level greater than 10 RPM were compared with those expressing ERBB2 at a level less than 10 RPM.
2016-08-25 | E-GEOD-75367 | biostudies-arrayexpress
Project description:This is a genomic analysis of breast cancer metastasis using array based CGH and is part of a large study investigating the patterns and evolution of metastases from breast cancer using autopsy material accumulated over the last 50 years from a single institution. The samples used in the genomic profiling comprise the primary breast tumour and multiple matched metastases from each patient. The data demonstrate both the clonal nature of metastatic progression and the role of clonal evolution during progression.
2013-11-11 | GSE46826 | GEO