Homo sapiens
Ontology highlight
ABSTRACT:
OTHER RELATED OMICS DATASETS IN: GSE58882
PROVIDER: PRJNA253806 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Coordinated epigenetic remodelling occurs during early breast carcinogenesis [ChIP-seq & MBD-Seq]
| PRJNA253805 | ENA
Project description:Coordinated epigenetic remodelling occurs during early breast carcinogenesis [Expression profiling]
| PRJNA253807 | ENA
Project description:To characterize early epigenetic events in breast carcinogenesis, we analyzed DNA methylation state of different stages of HMECs from pre-stasis to cancer cell lines using human promoter microarray
2009-01-01 | E-MEXP-1889 | biostudies-arrayexpress
Project description:Subpopulations of primary Human Mammary Epithelial Cells (HMEC) have the unique ability to escape a period of growth arrest and continue to proliferate. These cells, called post-selection or variant cells (vHMEC), share features with premalignant breast cancer lesions, including p16INK4A promoter hypermethylation. Epigenetic silencing of tumour suppressor genes through DNA methylation and histone modification is an early event in tumorigenesis. One of the main challenges is to find genes or gene pathways that are commonly silenced to provide early epigenetic diagnostic and therapeutic cancer targets. To identify very early epigenetic events that occur in breast cancer, we used microarrays to screen for gene pathways that were suppressed in post-selection HMECs, but reactivated after treatment with the demethylation agent 5-Aza-2â-deoxycytidine (5-Aza-dC). We found several members of the Transforming Growth Factor Beta (TGFb) signalling pathway (THBS1, TGFb2, TGFb R1 & TGFb R2) were consistently down-regulated in the post-selection HMEC population. Gene suppression was not associated with DNA methylation but was associated with chromatin remodelling, involving a decrease in histone H3 lysine 27 (H3K27) tri-methylation and an increase in histone H3 lysine 9 (H3K9) di-methylation and H3K9 de-acetylation. Similar epigenetic repression was also identified MDAMB453 breast cancer cells and in breast tumour samples. These results demonstrate for the first time that TGFb2, its receptors TGFb R1 & TGFb R2 and activator THBS1 are concordantly suppressed early in breast carcinogenesis by repressive histone modifications and indicate that the TGFb signalling pathway is a novel target for gene activation by epigenetic therapy. Keywords: cell differentiation, breast cancer, gene silencing, epigenetics Two-colour reference design was used. Two biological replicates were included in the study - Bre60 and Bre-80. Each cell line was sampled at pre-selection stage, post-selection stage and post AZA treatment. The post-selection stage was chosen as the reference sample, and a control post-post hybridisation included to assess variability across the assay.
2010-05-26 | E-GEOD-8007 | biostudies-arrayexpress
Project description:Subpopulations of primary Human Mammary Epithelial Cells (HMEC) have the unique ability to escape a period of growth arrest and continue to proliferate. These cells, called post-selection or variant cells (vHMEC), share features with premalignant breast cancer lesions, including p16INK4A promoter hypermethylation. Epigenetic silencing of tumour suppressor genes through DNA methylation and histone modification is an early event in tumorigenesis. One of the main challenges is to find genes or gene pathways that are commonly silenced to provide early epigenetic diagnostic and therapeutic cancer targets. To identify very early epigenetic events that occur in breast cancer, we used microarrays to screen for gene pathways that were suppressed in post-selection HMECs, but reactivated after treatment with the demethylation agent 5-Aza-2’-deoxycytidine (5-Aza-dC). We found several members of the Transforming Growth Factor Beta (TGFb) signalling pathway (THBS1, TGFb2, TGFb R1 & TGFb R2) were consistently down-regulated in the post-selection HMEC population. Gene suppression was not associated with DNA methylation but was associated with chromatin remodelling, involving a decrease in histone H3 lysine 27 (H3K27) tri-methylation and an increase in histone H3 lysine 9 (H3K9) di-methylation and H3K9 de-acetylation. Similar epigenetic repression was also identified MDAMB453 breast cancer cells and in breast tumour samples. These results demonstrate for the first time that TGFb2, its receptors TGFb R1 & TGFb R2 and activator THBS1 are concordantly suppressed early in breast carcinogenesis by repressive histone modifications and indicate that the TGFb signalling pathway is a novel target for gene activation by epigenetic therapy. Keywords: cell differentiation, breast cancer, gene silencing, epigenetics
2008-06-05 | GSE8007 | GEO
Project description:Forkhead box (Fox) proteins constitute an evolutionarily conserved family of transcriptional regulators whose deregulations lead to tumorigenesis. However, their regulation and function in gastric cancer are unknown. Promoter hypermethylation occurs during Helicobacter pylori (H pylori)-induced gastritis, but whether the deregulated genes contribute to the multi-step gastric carcinogenesis remains unclear. FOXD3 was found to be hypermethylated in a mouse model of H pylori infection and possess tumor-suppressive functions in gastric cancer cell lines. In order to characterize the direct targets of FOXD3 that confer its actions, we performed ChIP-chip in N87 gastric cancer cell line which express low level of FOXD3 in the nuclei of a sub-population of cells. Promoter hypermethylation occurs during Helicobacter pylori (H pylori)-induced gastritis, but whether the deregulated genes contribute to the multi-step gastric carcinogenesis remains unclear. We used MethylCap-microarray to identify hypermethylated genes in a mouse model of H pylori infection. human Samples: Human gastric tumor cell line, N87 was grown in RPMI1640 supplemented with 10% fetal bovine serum. ChIP assays were performed using anti-FOXD3 antibody. The immunoprecipitated-FOXD3 and -IgG DNA were used to probe the Agilent human ChIP-chip arrays. mouse Samples: Two-condition experiment, H pylori-infected vs. control gastric tissues. 2 dye-swap replicates.
2012-12-28 | E-GEOD-39490 | biostudies-arrayexpress
Project description:This work offers a dynamic picture of epigenetic switches in carcinogenesis and contributes to an overall understanding of coordinated regulation of gene expression in cancer. Our data indicate an H3K4me3/H3K27me3 epigenetic signature of prostate carcinogenesis.
2009-02-12 | E-TABM-635 | biostudies-arrayexpress
Project description:Forkhead box (Fox) proteins constitute an evolutionarily conserved family of transcriptional regulators whose deregulations lead to tumorigenesis. However, their regulation and function in gastric cancer are unknown. Promoter hypermethylation occurs during Helicobacter pylori (H pylori)-induced gastritis, but whether the deregulated genes contribute to the multi-step gastric carcinogenesis remains unclear. FOXD3 was found to be hypermethylated in a mouse model of H pylori infection and possess tumor-suppressive functions in gastric cancer cell lines. In order to characterize the direct targets of FOXD3 that confer its actions, we performed ChIP-chip in N87 gastric cancer cell line which express low level of FOXD3 in the nuclei of a sub-population of cells. Promoter hypermethylation occurs during Helicobacter pylori (H pylori)-induced gastritis, but whether the deregulated genes contribute to the multi-step gastric carcinogenesis remains unclear. We used MethylCap-microarray to identify hypermethylated genes in a mouse model of H pylori infection.
2012-12-28 | GSE39490 | GEO
Project description:<p>Understanding and explaining hereditary predisposition to cancer has focused on the genetic etiology of the disease. However, mutations in known genes associated with breast cancer such as BRCA1 and BRCA2 account for less than 25% of familial cases of breast cancer. Heritable epigenetic modifications, in the form of hypermethylated MLH1 promoter alleles, have recently been shown to promote hereditary nonpolyposis colorectal cancer. We investigated the potential for an epigenetic basis for hereditary breast cancer by performing deep bisulfite sequencing of CpG islands and known promoter regions in germline DNA from 100 familial or early-onset breast or ovarian cancer patients.</p>
| phs001699 | dbGaP