Nucleosome reorganisation in breast cancer tissues
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA865250 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Background Nucleosome repositioning in cancer is believed to cause many changes in genome organisation and gene expression. Understanding these changes is important to elucidate fundamental aspects of cancer. It is also important for medical diagnostics based on cell-free DNA (cfDNA), which originates from genomic DNA regions protected from digestion by nucleosomes. Results We have generated high-resolution nucleosome maps in paired tumour and normal tissues from the same breast cancer patients using MNase-assisted histone H3 ChIP-seq and compared them with the corresponding cfDNA from blood plasma. This analysis has detected single-nucleosome repositioning at key regulatory regions in a patient-specific manner and common cancer-specific patterns across patients. The nucleosomes gained in tumour versus normal tissue were particularly informative of cancer pathways, with ~ 20-fold enrichment at CpG islands, a large fraction of which marked promoters of genes encoding DNA-binding proteins. The tumour tissues were characterised by a 5–10 bp decrease in the average distance between nucleosomes (nucleosome repeat length, NRL), which is qualitatively similar to the differences between pluripotent and differentiated cells. This effect was correlated with gene activity, differential DNA methylation and changes in local occupancy of linker histone variants H1.4 and H1X. Conclusions Our study offers a novel resource of high-resolution nucleosome maps in breast cancer patients and reports for the first time the effect of systematic decrease of NRL in paired tumour versus normal breast tissues from the same patient. Our findings provide a new mechanistic understanding of nucleosome repositioning in tumour tissues that can be valuable for patient diagnostics, stratification and monitoring.
2024-04-17 | GSE210250 | GEO
Project description:BackgroundNucleosome repositioning in cancer is believed to cause many changes in genome organisation and gene expression. Understanding these changes is important to elucidate fundamental aspects of cancer. It is also important for medical diagnostics based on cell-free DNA (cfDNA), which originates from genomic DNA regions protected from digestion by nucleosomes.ResultsWe have generated high-resolution nucleosome maps in paired tumour and normal tissues from the same breast cancer patients using MNase-assisted histone H3 ChIP-seq and compared them with the corresponding cfDNA from blood plasma. This analysis has detected single-nucleosome repositioning at key regulatory regions in a patient-specific manner and common cancer-specific patterns across patients. The nucleosomes gained in tumour versus normal tissue were particularly informative of cancer pathways, with ~ 20-fold enrichment at CpG islands, a large fraction of which marked promoters of genes encoding DNA-binding proteins. The tumour tissues were characterised by a 5-10 bp decrease in the average distance between nucleosomes (nucleosome repeat length, NRL), which is qualitatively similar to the differences between pluripotent and differentiated cells. This effect was correlated with gene activity, differential DNA methylation and changes in local occupancy of linker histone variants H1.4 and H1X.ConclusionsOur study offers a novel resource of high-resolution nucleosome maps in breast cancer patients and reports for the first time the effect of systematic decrease of NRL in paired tumour versus normal breast tissues from the same patient. Our findings provide a new mechanistic understanding of nucleosome repositioning in tumour tissues that can be valuable for patient diagnostics, stratification and monitoring.
| S-EPMC10986098 | biostudies-literature
Project description:Changes of nucleosome organisation in breast cancer.
| PRJEB53594 | ENA
Project description:To screen candidate methylation markers for early detection of breast cancer, we performed methylated-CpG island recovery assay combined with CpG island array on 61982 CpG sites across 4162 genes in 10 breast tumor tissues and 10 non-tumor breast tissues. We detected 70 significantly hypermethylated genes in breast tumor tissues, including many novel hypermethylated genes such as ITGA4, NFIX, OTX2 and FGF12. Direct bisulfite sequencing showed widespread methylations occurred in intragenic regions of WT1, PAX6 and ITGA4 genes and promoter region of OTX2 in breast cancer tissue. COBRA assay in independent tumor and non-tumor samples confirmed that WT1, OTX2 and PAX6 genes were hypermethylated in breast cancer tissues. To explore the relationship between methylation and gene expression, gene expression profiling analysis was performed in 8 breast tumor tissues and 8 non-tumor breast tissues. We found that some hypermethylated genes in breast cancer were not expressed in breast tissues. RT-PCR assay showed that WT1 and PITX2 were only weakly expressed in the breast tumor tissues and weren’t expressed in most non-tumor breast tissues. OTX2 and PAX6 weren’t expressed in both breast tumor tissues and non-tumor tissues.
2011-11-11 | GSE33445 | GEO
Project description:To screen candidate methylation markers for early detection of breast cancer, we performed methylated-CpG island recovery assay combined with CpG island array on 61982 CpG sites across 4162 genes in 10 breast tumor tissues and 10 non-tumor breast tissues. We detected 70 significantly hypermethylated genes in breast tumor tissues, including many novel hypermethylated genes such as ITGA4, NFIX, OTX2 and FGF12. Direct bisulfite sequencing showed widespread methylations occurred in intragenic regions of WT1, PAX6 and ITGA4 genes and promoter region of OTX2 in breast cancer tissue. COBRA assay in independent tumor and non-tumor samples confirmed that WT1, OTX2 and PAX6 genes were hypermethylated in breast cancer tissues. To explore the relationship between methylation and gene expression, gene expression profiling analysis was performed in 8 breast tumor tissues and 8 non-tumor breast tissues. We found that some hypermethylated genes in breast cancer were not expressed in breast tissues. RT-PCR assay showed that WT1 and PITX2 were only weakly expressed in the breast tumor tissues and weren’t expressed in most non-tumor breast tissues. OTX2 and PAX6 weren’t expressed in both breast tumor tissues and non-tumor tissues. Unpaired experiments, breast cancer tissue vs. normal cancer tissue. Biological replicates: 10 breast cancer tissue replicates, 10 normal breast tissue replicates.
2011-11-11 | E-GEOD-33445 | biostudies-arrayexpress
Project description:To screen candidate methylation markers for early detection of breast cancer, we performed methylated-CpG island recovery assay combined with CpG island array on 61982 CpG sites across 4162 genes in 10 breast tumor tissues and 10 non-tumor breast tissues. We detected 70 significantly hypermethylated genes in breast tumor tissues, including many novel hypermethylated genes such as ITGA4, NFIX, OTX2 and FGF12. Direct bisulfite sequencing showed widespread methylations occurred in intragenic regions of WT1, PAX6 and ITGA4 genes and promoter region of OTX2 in breast cancer tissue. COBRA assay in independent tumor and non-tumor samples confirmed that WT1, OTX2 and PAX6 genes were hypermethylated in breast cancer tissues. To explore the relationship between methylation and gene expression, gene expression profiling analysis was performed in 8 breast tumor tissues and 8 non-tumor breast tissues. We found that some hypermethylated genes in breast cancer were not expressed in breast tissues. RT-PCR assay showed that WT1 and PITX2 were only weakly expressed in the breast tumor tissues and weren’t expressed in most non-tumor breast tissues. OTX2 and PAX6 weren’t expressed in both breast tumor tissues and non-tumor tissues.
2011-11-11 | GSE33447 | GEO
Project description:To screen candidate methylation markers for early detection of breast cancer, we performed methylated-CpG island recovery assay combined with CpG island array on 61982 CpG sites across 4162 genes in 10 breast tumor tissues and 10 non-tumor breast tissues. We detected 70 significantly hypermethylated genes in breast tumor tissues, including many novel hypermethylated genes such as ITGA4, NFIX, OTX2 and FGF12. Direct bisulfite sequencing showed widespread methylations occurred in intragenic regions of WT1, PAX6 and ITGA4 genes and promoter region of OTX2 in breast cancer tissue. COBRA assay in independent tumor and non-tumor samples confirmed that WT1, OTX2 and PAX6 genes were hypermethylated in breast cancer tissues. To explore the relationship between methylation and gene expression, gene expression profiling analysis was performed in 8 breast tumor tissues and 8 non-tumor breast tissues. We found that some hypermethylated genes in breast cancer were not expressed in breast tissues. RT-PCR assay showed that WT1 and PITX2 were only weakly expressed in the breast tumor tissues and weren’t expressed in most non-tumor breast tissues. OTX2 and PAX6 weren’t expressed in both breast tumor tissues and non-tumor tissues. Unpaired experiments, breast tumor tissues vs. breast non-tumor tissues. Biological replicates: 8 breast cancer tissue replicates, 8 breast non-tumor tissue replicates.
2011-11-11 | E-GEOD-33447 | biostudies-arrayexpress
Project description:This SuperSeries is composed of the following subset Series: GSE33445: DNA hypermethylation in breast cancer: breast cancer tissues vs. normal breast tissues GSE33447: Gene expression profiles in breast cancer: breast cancer tissues vs. normal breast tissues Refer to individual Series
2011-11-11 | E-GEOD-33450 | biostudies-arrayexpress
Project description:Nucleosome profiles for mammalian tissues
| PRJNA417272 | ENA
Project description:Expression data from breast cancer tissues and adjacent normal tissues
| PRJNA429856 | ENA