MRNA expression data from human breast cancer cell lines after demethylation treatment.
Ontology highlight
ABSTRACT: The contribution of aberrant DNA methylation and the downstream effects in tumorogenesis through silencing of tumor suppressor genes (TSGs) and microRNAs has been investigated. Since these epigenetic alterations can be reversed, we investigated the effects of the epigenetic therapy in breast cancer cell lines. We used microarrays to investigate the global gene expression profile after demethylation treatment with 5-aza-2’-deoxycytidine (DAC) in breast cancer cell lines and identified distinct classes of early and late systematic stable or transient effects of the treatment.
Project description:The contribution of aberrant DNA methylation and the downstream effects in tumorogenesis through silencing of tumor suppressor genes (TSGs) and microRNAs has been investigated. Since these epigenetic alterations can be reversed, we investigated the effects of the epigenetic therapy in breast cancer cell lines. We used microarrays to investigate the global microRNA expression profile after demethylation treatment with 5-aza-2’-deoxycytidine (DAC) in breast cancer cell lines and identified distinct classes of early and late systematic stable or transient effects of the treatment.
Project description:The contribution of aberrant DNA methylation and the downstream effects in tumorogenesis through silencing of tumor suppressor genes (TSGs) and microRNAs has been investigated. Since these epigenetic alterations can be reversed, we investigated the effects of the epigenetic therapy in breast cancer cell lines. We used microarrays to investigate the global microRNA expression profile after demethylation treatment with 5-aza-2’-deoxycytidine (DAC) in breast cancer cell lines and identified distinct classes of early and late systematic stable or transient effects of the treatment. Three selected breast cell lines including MDA-MB231, SKBR3, BT549, HS578T, MCF7 and HB2 (a breast epithelial cell line as control) were subject for miRNA isolation before treatment, after treatment with DAC and at five point follow-ups (1st, 3rd, 5th, 7th and 10th passages) at “drug holiday” condition and hybridized on Affymetrix microarrays.
Project description:The contribution of aberrant DNA methylation and the downstream effects in tumorogenesis through silencing of tumor suppressor genes (TSGs) and microRNAs has been investigated. Since these epigenetic alterations can be reversed, we investigated the effects of the epigenetic therapy in breast cancer cell lines. We used microarrays to investigate the global gene expression profile after demethylation treatment with 5-aza-2’-deoxycytidine (DAC) in breast cancer cell lines and identified distinct classes of early and late systematic stable or transient effects of the treatment. Three selected breast cell lines including MDA-MB231 (a highly aggressive cell line), SKBR3 (a non-aggressive cell line) and HB2 (a breast epithelial cell line as control) were subject for RNA isolation before treatment, after treatment with DAC and at five point follow-ups (1st, 3rd, 5th, 7th and 10th passages) at “drug holiday” condition and hybridized on Affymetrix microarrays.
Project description:Recently, the H3K4 demethylase, KDM5B, was shown to be amplified and overexpressed in luminal breast cancer, suggesting it might constitute a potential cancer therapy target. Here, we characterize, in breast cancer cells, the molecular effects of a recently developed small-molecule inhibitor of the KDM5 family of proteins, either alone, or in combination with the DNA demethylating agent 5-aza-2’ deoxycytidine (DAC). Alone, the KDM5 inhibitor (KDM5i) increased expression of a small number of genes, but when combined with DAC, the drug enhanced the effects of the latter for increasing expression of hundreds of DAC responsive genes. ChIP-seq studies revealed that KDM5i resulted in the broadening of existing, and creation of thousands of new H3K4me3 domains. When compared to DAC alone, increased promoter and gene body H3K4me3 occupancy at DAC responsive genes was observed in cells treated with the drug combination. Importantly, treatment with either DAC or DAC+KDM5i induced a dramatic increase in H3K27ac at enhancers with an associated significant increase in target gene expression, suggesting a previously unappreciated effect of DAC on transcriptional regulation. Finally, we found that KDM5i could synergize with DAC to reduce the viability of luminal breast cancer cells in in-vitro assays. Our study provides the first look into the molecular effects of novel KDM5i compounds and suggests that combining these with DAC may represent an exciting new approach to epigenetic therapy.
Project description:Recently, the H3K4 demethylase, KDM5B, was shown to be amplified and overexpressed in luminal breast cancer, suggesting it might constitute a potential cancer therapy target. Here, we characterize, in breast cancer cells, the molecular effects of a recently developed small-molecule inhibitor of the KDM5 family of proteins, either alone, or in combination with the DNA demethylating agent 5-aza-2’ deoxycytidine (DAC). To determine the effects of these compounds on global gene expression, we used the Agilend Whole Human Genome 4x44k v2 Microarray. We found that alone, the KDM5 inhibitor (KDM5i) increased expression of a small number of genes, but when combined with DAC, the drug enhanced the effects of the latter for increasing expression of hundreds of DAC responsive genes.
Project description:Aberrant expression of microRNA (miRNA) has been reported in various cancers. To clarify the role of miRNA in gastric carcinogenesis, we performed miRNA microarray analysis and investigated expressional changes of miRNAs in a 5-aza-2'-deoxycytidine (DAC)-treated gastric cancer cell line, KATO-ІІІ.
Project description:Genome wide DNA methylation profiling of colorectal cancer cell lines treated with acetyl-11-keto-β-boswellic acid (AKBA) or 5-aza-2’-deoxycytidine (DAC). The Illumina Infinium 27k Human DNA methylation Beadchip v1.2 was used to obtain DNA methylation profiles across approximately 27,000 CpGs in the colorectal cancer cell line SW48. Samples included non-treated, AKBA-treated, and DAC-treated SW48 cells.
Project description:Recently, the H3K4 demethylase, KDM5B, was shown to be amplified and overexpressed in luminal breast cancer, suggesting it might constitute a potential cancer therapy target. Here, we characterize, in breast cancer cells, the molecular effects of a recently developed small-molecule inhibitor of the KDM5 family of proteins, either alone, or in combination with the DNA demethylating agent 5-aza-2’ deoxycytidine (DAC). Alone, the KDM5 inhibitor (KDM5i) increased expression of a small number of genes, but when combined with DAC, the drug enhanced the effects of the latter for increasing expression of hundreds of DAC responsive genes. To determine if this combinatorial action was the result of enhanced DNA demethylation, we profiled genome-wide DNA methylation in cells treated with KDM5i, DAC, or both. Methylation levels at approximately 450,000 unique CpG loci were detected using the Infinium Illumina HumanMethylation 450 array. We found that KDM5i did not significantly affect DNA methylation either alone, or in combination with DAC.
Project description:Promoter methylation was assayed in a number of breast cancer and control normal samples along with the effects of 5'-aza-2'-deoxycytidine on breast cancer cell line transcriptomes. Aberrant promoter hypermethylation is frequently observed in cancer. The potential for this to contribute to tumour development depends on whether the genes affected are repressed because of their methylation. Many aberrantly methylated genes play important roles in development and are bivalently marked in ES cells suggesting that their aberrant methylation may reflect developmental processes. We investigated this possibility by analysing promoter methylation in 19 breast cancer cell lines, 10 normal tissues and 47 primary breast tumours. In order to determine the role of DNA methylation in silencing genes in breast cancer, we also examined the effects of the demethylating agent 5-aza-2?-deoxycytidine on gene expression in 3 breast cancer cell lines and HCT116 cells. Gene expression changes were also assayed in the DNA methyltransferase deficient HCT116 DKO cell line. Our findings implicate aberrant DNA methylation as a marker of cell lineage rather than tumour progression and suggest that, in most cases, it does not cause the repression with which it is associated. A number of human breast cancer cell lines, breast tumours and normal tissues were analysed on Illumina Infinium Methylation27 Beadchips to assay promoter methylation. Selected cell lines were analysed on expression arrays before and after treatment with 5-aza-2'-deoxycytidine.