Project description:During cancer development and progression massive alterations in gene expression have been observed. The regulation of genes occurs within the context of the 3D genome. However, the impact of disease progression on the 3D structure of the genome remains poorly understood. Using breast cancer as a model we have profiled the 3D genome throughout the natural course of the disease; from development to progression. Uniquely, we analysed tumours from the same patients, enabling us to gauge the extent of changes that happen upon metastasis. Our results show that the organization of genome at the level of topologically associating domains (TADs) and compartments upon tumorigenesis and metastasis, is remarkably stable. However, in pleural metastases, representing heavily pretreated progressive disease, the 3D genome is massively affected, and highly heterogeneous between patients, both on the compartment and TAD level. Our data reveal that disease progression in breast cancer is associated with a progressive unravelling of the 3D genome.
Project description:During cancer development and progression massive alterations in gene expression have been observed. The regulation of genes occurs within the context of the 3D genome. However, the impact of disease progression on the 3D structure of the genome remains poorly understood. Using breast cancer as a model we have profiled the 3D genome throughout the natural course of the disease; from development to progression. Uniquely, we analysed tumours from the same patients, enabling us to gauge the extent of changes that happen upon metastasis. Our results show that the organization of genome at the level of topologically associating domains (TADs) and compartments upon tumorigenesis and metastasis, is remarkably stable. However, in pleural metastases, representing heavily pretreated progressive disease, the 3D genome is massively affected, and highly heterogeneous between patients, both on the compartment and TAD level. Our data reveal that disease progression in breast cancer is associated with a progressive unravelling of the 3D genome.
Project description:Breast cancer progression entails intricate, multi-level alterations in genome organization and expression. To gain insights into the modifications in chromatin's three-dimensional (3D) structure during breast cancer progression, we conducted an analysis combining Hi-C data with lamina-associated domains (LADs), epigenomic marks, and gene expression in an in vitro model of breast cancer progression. Our results reveal that while the fundamental properties of topologically associating domains (TADs) remain largely stable, significant changes occur in the organization of compartments and subcompartments. These changes are closely correlated with alterations in the expression of oncogenic genes. We also observed a restructuring of TAD-TAD interactions, coinciding with a loss of spatial compartmentalization and radial positioning of the 3D genome. Notably, we identified a previously unrecognized interchromosomal insertion event, wherein a locus on chromosome 8 housing the MYC oncogene becomes inserted into a highly active region on chromosome 10. This insertion event leads to the formation of de novo enhancer contacts and activation of the oncogene, illustrating how structural variants can interact with the 3D genome to drive oncogenic states. In summary, our findings provide evidence for the degradation of genome organization at multiple scales during breast cancer progression revealing the complex interplay between genomic structure and oncogenic processes.
Project description:Breast cancer progression entails intricate, multi-level alterations in genome organization and expression. To gain insights into the modifications in chromatin's three-dimensional (3D) structure during breast cancer progression, we conducted an analysis combining Hi-C data with lamina-associated domains (LADs), epigenomic marks, and gene expression in an in vitro model of breast cancer progression. Our results reveal that while the fundamental properties of topologically associating domains (TADs) remain largely stable, significant changes occur in the organization of compartments and subcompartments. These changes are closely correlated with alterations in the expression of oncogenic genes. We also observed a restructuring of TAD-TAD interactions, coinciding with a loss of spatial compartmentalization and radial positioning of the 3D genome. Notably, we identified a previously unrecognized interchromosomal insertion event, wherein a locus on chromosome 8 housing the MYC oncogene becomes inserted into a highly active region on chromosome 10. This insertion event leads to the formation of de novo enhancer contacts and activation of the oncogene, illustrating how structural variants can interact with the 3D genome to drive oncogenic states. In summary, our findings provide evidence for the degradation of genome organization at multiple scales during breast cancer progression revealing the complex interplay between genomic structure and oncogenic processes.
Project description:Breast cancer progression entails intricate, multi-level alterations in genome organization and expression. To gain insights into the modifications in chromatin's three-dimensional (3D) structure during breast cancer progression, we conducted an analysis combining Hi-C data with lamina-associated domains (LADs), epigenomic marks, and gene expression in an in vitro model of breast cancer progression. Our results reveal that while the fundamental properties of topologically associating domains (TADs) remain largely stable, significant changes occur in the organization of compartments and subcompartments. These changes are closely correlated with alterations in the expression of oncogenic genes. We also observed a restructuring of TAD-TAD interactions, coinciding with a loss of spatial compartmentalization and radial positioning of the 3D genome. Notably, we identified a previously unrecognized interchromosomal insertion event, wherein a locus on chromosome 8 housing the MYC oncogene becomes inserted into a highly active region on chromosome 10. This insertion event leads to the formation of de novo enhancer contacts and activation of the oncogene, illustrating how structural variants can interact with the 3D genome to drive oncogenic states. In summary, our findings provide evidence for the degradation of genome organization at multiple scales during breast cancer progression revealing the complex interplay between genomic structure and oncogenic processes.
Project description:Organoids or spheroids have emerged as a physiologically relevant in vitro preclinical model to study patient-specific diseases. A recent study used spheroids of MCF10 cells to model breast cancer progression and identified targetable alterations more similar to those in vivo. Thus, it is practical and essential to explore and characterize the spheroids of the commonly used human breast cancer (BC) cells. This study conducted Hi-C analyses in three-dimensional (3D) spheroids of MCF10A, MCF7 and MCF7TR cells and compared TADs and looping genes with those in 2D monolayers. We found that chromatin domains and looping genes’ strength have drastically changed during the 3D culture growth, although we identified very similar numbers of TADs and looping genes. We further identified novel 3D growth-specific looping genes within Hippo relevant pathways, of which two genes showed potential prognostic values in measuring the outcome of the endocrine treatment. We finally confirmed a few selected Hippo relevant pathways genes with enhanced looping in breast cancer patient tissues’ organoid. Hence, our work has provided significant insights into our understanding of 3D-growth-specific chromatin architecture in tamoxifen-resistant breast cancer.
Project description:Breast cancer progression entails intricate, multi-level alterations in genome organization and expression. To gain insights into the modifications in chromatin's three-dimensional (3D) structure during breast cancer progression, we conducted an analysis combining Hi-C data with lamina-associated domains (LADs), epigenomic marks, and gene expression in an in vitro model of breast cancer progression. Our results reveal that while the fundamental properties of topologically associating domains (TADs) remain largely stable, significant changes occur in the organization of compartments and subcompartments. These changes are closely correlated with alterations in the expression of oncogenic genes. We also observed a restructuring of TAD-TAD interactions, coinciding with a loss of spatial compartmentalization and radial positioning of the 3D genome. Notably, we identified a previously unrecognized interchromosomal insertion event, wherein a locus on chromosome 8 housing the MYC oncogene becomes inserted into a highly active region on chromosome 10. This insertion event leads to the formation of de novo enhancer contacts and activation of the oncogene, illustrating how structural variants can interact with the 3D genome to drive oncogenic states. In summary, our findings provide evidence for the degradation of genome organization at multiple scales during breast cancer progression revealing the complex interplay between genomic structure and oncogenic processes.
Project description:Triple-negative breast cancer (TNBC) is malignant cancer with a high risk of recurrence. To date, the underlying 3D chromatin organizations of TNBC have remained unclear. Here, using in situ Hi-C, we characterized the 3D chromatin organizations in cells representing five distinct subtypes of breast cancer (including TNBC) and TNBC tissues, compared to normal cells/tissues. We found that the global and local 3D architectures are severely disrupted in TNBC cells. Importantly, we detected CTCF-dependent TNBC-susceptible loss/gain of 3D chromatin organizations and found that these changes were strongly associated with perturbed chromatin accessibility and transcriptional dysregulations. Although some discrepancies exist between TNBC cell lines and tissues, we observed that perturbed local 3D architectures found in TNBC cells are partially conserved in TNBC tissues. Furthermore, we discovered distinct tissue-specific chromatin loops by comparing normal and TNBC tissues. Collectively, our findings provide important features of 3D chromatin organization in TNBC.