Homo sapiens
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA131437 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:We have systematically profiled DNA methylation at promoter CpG islands (CGIs) in ovarian cancer. Epithelial ovarian tumours, excluding mucinous and clear cell cancers, prospectively collected through a cohort study, were analyzed by differential methylation hybridization (DMH) (Nouzova M et al, 2004) in duplicates. The loci targeted by the custom-designed microarray are the promoter CpG islands (Gardiner-Garden and Frommer, 1987) of the genes involved in the Wnt, p53, AKT/mTOR, BRCA1/2 and Redox pathways, DNA repair (HR, NHEJ and MMR), FA family and IgLON family. 111 ovarian tumor samples were assayed by DMH in duplicates. McrBC digested (Cy5) and undigested (Cy3) samples were competitively hybridized on the Agilent custom-designed microarrays 8x15k.
2011-06-01 | E-GEOD-23240 | biostudies-arrayexpress
Project description:We have systematically profiled DNA methylation at promoter CpG islands (CGIs) in ovarian cancer. Epithelial ovarian tumours, excluding mucinous and clear cell cancers, prospectively collected through a cohort study, were analyzed by differential methylation hybridization (DMH) (Nouzova M et al, 2004) in duplicates. The loci targeted by the custom-designed microarray are the promoter CpG islands (Gardiner-Garden and Frommer, 1987) of the genes involved in the Wnt, p53, AKT/mTOR, BRCA1/2 and Redox pathways, DNA repair (HR, NHEJ and MMR), FA family and IgLON family.
2011-06-01 | GSE23240 | GEO
Project description:Methylation of CpG islands associated with genes can affect the expression of the proximal gene, and methylation of non associated CpG islands correlates to genomic instability. This epigenetic modification has been shown to be important in many pathologies, from development and disease to cancer. We report the development of a novel high-resolution microarray that detects the methylation status of over 25,000 CpG islands in the human genome. Experiments were performed to demonstrate low system noise in the methodology and that the array probes have a high signal to noise ratio. Methylation measurements between different cell lines were validated demonstrating the accuracy of measurement. We then identified alterations in CpG islands, both those associated with gene promoters, as well as non-promoter associated islands in a set of breast and ovarian tumors. We demonstrate that this methodology accurately identifies methylation profiles in cancer and in principle it can differentiate any CpG methylation alterations and can be adapted to analyze other species. We have developed a method to profile genome wide methylation. 7 ovarian normal samples and 11 tumor samples from other individuals were analyzed for CpG methylation. After inter array normalization, the tumor samples were taken together and the methylation compared to that of the normal samples to identify regions of the CpG islands that are significantly altered between the two datasets. Some of these regions were validated for their methylation as a proof of principle for the method.
2010-05-19 | E-GEOD-15747 | biostudies-arrayexpress
Project description:Methylation of CpG islands associated with genes can affect the expression of the proximal gene, and methylation of non associated CpG islands correlates to genomic instability. This epigenetic modification has been shown to be important in many pathologies, from development and disease to cancer. We report the development of a novel high-resolution microarray that detects the methylation status of over 25,000 CpG islands in the human genome. Experiments were performed to demonstrate low system noise in the methodology and that the array probes have a high signal to noise ratio. Methylation measurements between different cell lines were validated demonstrating the accuracy of measurement. We then identified alterations in CpG islands, both those associated with gene promoters, as well as non-promoter associated islands in a set of breast and ovarian tumors. We demonstrate that this methodology accurately identifies methylation profiles in cancer and in principle it can differentiate any CpG methylation alterations and can be adapted to analyze other species.
2009-04-28 | GSE15747 | GEO
Project description:Methylation of CpG islands associated with genes can affect the expression of the proximal gene, and methylation of non associated CpG islands correlates to genomic instability. This epigenetic modification has been shown to be important in many pathologies, from development and disease to cancer. We report the development of a novel high-resolution microarray that detects the methylation status of over 25,000 CpG islands in the human genome. Experiments were performed to demonstrate low system noise in the methodology and that the array probes have a high signal to noise ratio. Methylation measurements between different cell lines were validated demonstrating the accuracy of measurement. We then identified alterations in CpG islands, both those associated with gene promoters, as well as non-promoter associated islands in a set of breast and ovarian tumors. We demonstrate that this methodology accurately identifies methylation profiles in cancer and in principle it can differentiate any CpG methylation alterations and can be adapted to analyze other species.
2009-04-28 | GSE15746 | GEO
Project description:Methylation of CpG islands associated with genes can affect the expression of the proximal gene, and methylation of non associated CpG islands correlates to genomic instability. This epigenetic modification has been shown to be important in many pathologies, from development and disease to cancer. We report the development of a novel high-resolution microarray that detects the methylation status of over 25,000 CpG islands in the human genome. Experiments were performed to demonstrate low system noise in the methodology and that the array probes have a high signal to noise ratio. Methylation measurements between different cell lines were validated demonstrating the accuracy of measurement. We then identified alterations in CpG islands, both those associated with gene promoters, as well as non-promoter associated islands in a set of breast and ovarian tumors. We demonstrate that this methodology accurately identifies methylation profiles in cancer and in principle it can differentiate any CpG methylation alterations and can be adapted to analyze other species. We have developed a method to profile genome wide methylation. 12 breast normal samples and matching tumors from these individuals and an additional 28 tumor samples from other individuals were analyzed for CpG methylation. After inter array normalization, the tumor samples were taken together and the methylation compared to that of the normal samples to identify regions of the CpG islands that are significantly altered between the two datasets. Some of these regions were validated for their methylation as a proof of principle for the method.
2009-04-28 | E-GEOD-15746 | biostudies-arrayexpress
Project description:Genome-wide DNA methylation profiles were determined on a set of fresh 44 bladder cancer tissues using normal blood as control. DNA amplicons were prepared using Differential Methylation Hybridization (DMH) method, subsequently hybridized on to the Agilent Human CpG island Microarray. The goal was to unravel the DNA methylation patterns in different subgropus of bladder cancer along with finding markers for progresssion and early diagnosis.
2012-02-16 | GSE35824 | GEO
Project description:Cisplatin and carboplatin are the primary first-line therapies for the treatment of ovarian cancer. However, resistance to these platinum-based drugs occurs in the large majority of initially responsive tumors, subsequently resulting in a poor long-term prognosis. To model the onset of drug resistance, and investigate the DNA methylation alterations associated with cisplatin resistance, we treated clonally derived, drug-sensitive A2780 epithelial ovarian cancer cells with increasing concentrations of cisplatin. After several cycles of drug selection, the isogenic drug-sensitive and -resistant pairs were subjected to global CGI methylation microarray analyses. We treated clonally derived, drug-sensitive A2780 epithelial ovarian cancer cells with increasing concentrations of cisplatin. After several cycles of drug selection, the isogenic drug-sensitive and -resistant pairs were subjected to global CGI methylation analyses by differential methylation hybridization (DMH) using a customed 44K promoter CGI microarray.
2010-06-19 | E-GEOD-15373 | biostudies-arrayexpress
Project description:Genome-wide DNA methylation profiles were determined on a set of fresh 44 bladder cancer tissues using normal blood as control. DNA amplicons were prepared using Differential Methylation Hybridization (DMH) method, subsequently hybridized on to the Agilent Human CpG island Microarray. The goal was to unravel the DNA methylation patterns in different subgropus of bladder cancer along with finding markers for progresssion and early diagnosis. 44 bladder cancer tissues were profiled against commercially available normal human genomic blood DNA (Promega, Madison, WI, USA) as a reference
2012-02-16 | E-GEOD-35824 | biostudies-arrayexpress
Project description:Multiple DNA methylation changes have been associated with the acquisition of drug resistance; however it remains uncertain how many of these changes may represent critical DNA methylation drivers of chemoresistance. Using genome-wide DNA methylation profiling across 27,578 CpG sites on Illumina HumanMethylation27 bead array we identified loci at 4092 genes becoming hypermethylated in the chemoresistant A2780/cp70 ovarian tumour cell line compared to the parental sensitive A2780 line. Hypermethylation at CpG islands (CGI) is often associated with transcriptional silencing, however only 245 of these hypermethylated genes become down-regulated in A2780/cp70 as measured by microarray expression profiling. Treatment with the demethylating agent Decitabine induces re-sensitisation to cisplatin and resulted in re-expression of 41 of the down-regulated genes in cisplatin-resistant cells at the time point when re-sensitisation occurs. 13 of the 41 genes were consistently hypermethylated in two further independent cisplatin-resistant A2780 cell derivatives. Nine out of the 13 genes (ARHGDIB, ARMCX2, COL1A, FLNA, FLNC, MEST, MLH1, NTS, PSMB9) acquired methylation at CpG sites in ovarian tumours at relapse following chemotherapy or chemoresistant cell lines derived at the time of patient relapse. Furthermore, 5/13 candidate genes acquired methylation in drug-resistant in vivo-derived ovarian cancer sustaining (side population) cells. Therefore, this small set of genes are potential key drivers of chemoresistance and should be further evaluated as predictive biomarkers, both to existing chemotherapies, but also to epigenetic therapies used to modulate drug resistance. Array-based methylation profiling was performed using the Infinium HumanMethylation27 BeadChip in two cisplatin sensitive cell lines and three cisplatin resistant cell lines derived in vitro, four pairs of cisplatin sensitive and resistant cell lines derived in vivo, 7 pairs of tumour tissues obtained from patients before chemotherapy and at disease relapse, 2 pairs of IGROV1 SP and NSP cells. The reproducibility of the Infinium HumanMethylation27 BeadChips was evaluated using biological and technical replicates of matched chemosensitive/chemoresistant ovarian cancer cell lines PEO1/PEO4. Differential methylation cutoff was estimated from two biological replicates by bootstrap resampling.
2011-12-20 | E-GEOD-28647 | biostudies-arrayexpress