Gene expression following epigenetic drug treatment
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Pedro Jares
PROVIDER: E-GEOD-22038 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
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Project description:Expression profiling the response to inhibition of DNA methylation and histone deacetylation. Comparison of expression in HepG2 cells treated with 5-aza-dC, Trichostatin A, both, or none (control) to change methylation and acetylation status. Backgroubd: DNA methylation and histone deacetylation are epigenetic mechanisms that play major roles in eukaryotic gene regulation. We hypothesize that many genes in the human hepatoma cell line HepG2 are regulated by DNA methylation and histone deacetylation. Treatment with 5-aza-2'-deoxycytidine (5-aza-dC) to inhibit DNA methylation with and/or Trichostatin A (TSA) to inhibit histone deacetylation should allow us to identify genes that are regulated epigenetically in hepatoma cells. RESULTS: 5-aza-dC had a much larger effect on gene expression in HepG2 cells than did TSA, as measured using Affymetrix HG-U133 Plus 2.0 microarrays. The expression of 1504 probe sets was affected by 5-aza-dC (at p < 0.01), 535 probe sets by TSA, and 1929 probe sets by the combination of 5-aza-dC and TSA. 5-aza-dC treatment turned on the expression of 211 probe sets that were not detectably expressed in its absence. Expression of imprinted genes regulated by DNA methylation, such as H19 and NNAT, was turned on or greatly increased in response to 5-aza-dC. Genes involved in liver processes such as xenobiotic metabolism (CYP3A4, CYP3A5, and CYP3A7) and steroid biosynthesis (CYP17A1 and CYP19A1), and genes encoding CCAAT element-binding proteins (C/EBPalpha, C/EBPbeta, and C/EBPgamma) were affected by 5-aza-dC or the combination. Many of the genes that fall within these groups are also expressed in the developing fetal liver and adult liver. Quantitative real-time RT-PCR assays confirmed selected gene expression changes seen in microarray analyses. CONCLUSION: Epigenetics play a role in regulating the expression of several genes involved in essential liver processes such as xenobiotic metabolism and steroid biosynthesis in HepG2 cells. Many genes whose expression is normally silenced in these hepatoma cells were re-expressed by 5-aza-dC treatment. DNA methylation may be a factor in restricting the expression of fetal genes during liver development and in shutting down expression in hepatoma cells
2007-10-27 | E-GEOD-5230 | biostudies-arrayexpress
Project description:MCL cell lines were treated with aza and aza in combination with TSA.
2013-01-31 | GSE22038 | GEO
Project description:Expression data from pancreatic cancer cell lines and non-neoplastic pancreatic cell line HPDE To identify genes epigenetically silenced and regulated in pancreatic cancer We compared the gene expression profiles of 6 pancreatic cancer cell lines (panc215, A32-1, A38-5, panc2.5, panc2.8, and panc3.014), to the non-neoplastic pancreas cell line, HPDE. We also compared the baseline gene expression of the pancreatic cancer cell lines to expression patterns after treatment with 5-aza-dC alone, TSA alone, and to a combination of 5-aza-dC/TSA.
2010-04-14 | E-GEOD-21163 | biostudies-arrayexpress
Project description:Purpose: The major aim of this study was to investigate the role of DNA methylation (referred to as methylation) on microRNA (miRNA) silencing in non-small cell lung cancers (NSCLC). Experimental Design: We performed microarray expression analyses of 856 miRNAs in NSCLC A549 cells before and after treatment with the DNA methyltransferase inhibitor 5-aza-2´-deoxycytidine (Aza-dC) and with a combination of Aza-dC and the histone deacetylase inhibitor trichostatin A. MiRNA methylation was determined in 11 NSCLC cell lines and in primary tumors and corresponding non-malignant lung tissue samples of 101 stage I-III NSCLC patients. Results: By comparing microarray data of untreated and drug treated A549 cells, we identified 33 miRNAs whose expression was upregulated after drug treatment and which are associated with a CpG island. Thirty (91%) of these miRNAs were found to be methylated in at least 1 of 11 NSCLC cell lines analysed. Moreover, miR-9-3 and miR-193a were found to be tumor-specifically methylated in NSCLC patients. We observed a shorter disease-free survival of miR-9-3 methylated lung squamous cell carcinoma (LSCC) patients compared to miR-9-3 unmethylated LSCC patients by multivariate analysis (HR = 3.8, 95% CI = 1.3 to 11.2, p = 0.017) and a shorter overall survival of miR-9-3 methylated LSCC patients compared to miR-9-3 unmethylated LSCC patients by univariate analysis (p = 0.013). Conclusions: Overall, our results suggest that methylation is an important mechanism for inactivation of certain miRNAs in NSCLCs and that miR-9-3 methylation may serve as a prognostic parameter in LSCC patients. MiRNA expression (LC Sciences, mirBASE12) was analyzed before and after treatment of A549 cells with 5-aza-2´-deoxycytidine (Aza-dC) and a combination of Aza-dC and trichostatin A (TSA). Experiments were performed in duplicates.
2012-03-13 | E-GEOD-31579 | biostudies-arrayexpress
Project description:Background Epigenetic changes are involved in the extinction of the B-cell gene expression program of classical Hodgkin lymphoma. However, little is known regarding epigenetic similarities between classical Hodgkin lymphoma and plasma cell myeloma cells, both of which share an extinction of the gene expression program of mature B-cells. Design and methods Global histone H3 acetylation patterns were determined in cell lines derived from classical Hodgkin lymphoma, plasma cell myeloma and B-cell lymphoma by chromatin immunoprecipitation and subsequent hybridization onto promoter tiling arrays. H3K27 trimethylation was analyzed by chromatin immunoprecipitation and real-time DNA-PCR for selected genes. Epigenetic modifications were compared to gene expression data. Results B-cell characteristic genes were hypoacetylated in classical Hodgkin lymphoma and plasma cell myeloma cell lines, as demonstrated by comparison of their histone H3 acetylation patterns to those of B-cell lines. However, the number of genes jointly hyperacetylated and expressed in classical Hodgkin lymphoma and plasma cell myeloma cell lines, such as IFR4/MUM1 and RYBP, is limited. Moreover, H3K27 trimethylation for selected B-cell characteristic genes revealed that this additional epigenetic silencing is much more prevalent in classical Hodgkin lymphoma as compared to plasma cell myeloma. Conclusion Our epigenetic data support the view that classical Hodgkin lymphoma is characterized by an abortive plasma cell differentiation with a down-regulation of B-cell characteristic genes but without activation of most plasma cell typical genes. Combined 5-aza-dC/TSA (A/T) treatment: The diffuse large B-cell lymphoma (DLBCL)-derived cell lines SU-DHL4, SU-DHL6 and HT and the Burkitt lymphoma-derived cell lines Daudi, Namalwa and Raji were treated with 5-aza-dC at a concentration of 3 µM for 6 days. 5-aza-dC and medium was replaced at day 2 and 5. At the fifth day - in addition to 3 µM 5-aza-dC - cells were incubated for 24 hours with 625 nM TSA. RNA was isolated according to standard protocols (Qiagen, Hilden, Germany) and used for Affymetrix GeneChip hybridization (HG-U133A). Microarrays were normalized using RMA and differential expression was calculated using moderated t-test. The gene expression profiles of the untreated and treated cell lines (with the exception of HT) were generated in duplicates. Microarray data (CEL files) for AZA/TSA-treated BL-derived cell lines Raji, Daudi and Namalwa were previously published (GEO accession GSE8388).
2011-05-05 | E-GEOD-21252 | biostudies-arrayexpress
Project description:Epigenetic changes largely contribute to the regulation of gene expression in cancer cells. DNA methylation is part of the epigenetic gene regulation complex which is relevant for the pathogenesis of cancer. We performed a genome-wide search for methylated CpG islands in tumors and corresponding non-malignant lung tissue samples of 101 stage I-III non-small cell lung cancer (NSCLC) patients by combining methylated DNA immunoprecipitation and microarray analysis using NimbleGenM-BM-4s 385K Human CpG Island plus Promoter arrays. By testing for differences in methylation between tumors and corresponding non-malignant lung tissues, we identified 298 tumor-specifically methylated genes. From many of these genes epigenetic regulation was unknown so far. Gene Ontology analysis revealed an over-representation of genes involved in regulation of gene expression and cell adhesion. Expression of 182 of 298 genes was found to be upregulated after 5-aza-2M-BM-4-deoxycytidine (Aza-dC) and/or trichostatin A (TSA) treatment of 3 NSCLC cell lines by Affymetrix microarray analysis. In addition, methylation of selected genes in primary NSCLCs and corresponding non-malignant lung tissue samples were analyzed by methylation-sensitive high resolution melting analysis (MS-HRM). Our results obtained by MS-HRM analysis confirmed our data obtained by MeDIP-chip analysis. Moreover, by comparing methylation results from MeDIP-chip analysis with clinico-pathological parameters of the patients we observed methylation of HOXA2 as potential parameter for shorter disease-free survival of NSCLC patients. In conclusion, using a genome-wide approach we identified a large number of tumor-specifically methylated genes in NSCLC patients. Our results stress the importance of DNA methylation for the pathogenesis of NSCLCs. Overall, samples of 3 untreated, with Aza-dC treated and with Aza-dC/TSA treated NSCLC cell lines were hybridized to Affymetrix HG-U133_plus_2.0 microarrays (18 in total).
2012-11-26 | E-GEOD-32496 | biostudies-arrayexpress
Project description:To understand the roles of DNA methylation and histone deacetylation in plant gene network that controls plant tolerance to freezing treatment, we used Affymetrix GeneChips ATH-121501 to analysis. For microarray analysis, Arabidopsis (ecotype Columbia) seedlings grew in four types of sterile growth medium: no any other modifying agents, added 7g/ml 0.5 M aza-dC in water (DNA methylation inhibitor), added TSA in methanol (histone deacetylation inhibitor), both aza-dC and TSA, all for 16 day in growth chamber (16-h day length at 70% relative humidity, 23 M-BM-0C) , then all seedlings were cold treated at 0 M-BM-0C for 24 h in growth chamber (16-h day length at 70% relative humidity). A total of 3305 genes expression were statistically analysized. Our study provides some clues that the transcript levels of some cold-responsive genes regulated by DNA methylation and histone deacetylation. This will be valuable for understanding gene regulation by epigenetic modifications under freezing stress. Keywords: Cold Stress response, DNA methylation, histone deacetylation Three replicates for aza-dc and TSA treatment, and two replicates for Mock and both aza-dc and TSA treatment. All samples were treated 0M-BM-0C 24h.
2015-01-20 | E-GEOD-63131 | biostudies-arrayexpress
Project description:Reversal of gene promoter DNA hypermethylation and associated abnormal gene silencing is an attractive approach to cancer therapy. The DNA methylation inhibitor, decitabine (5-aza-2'-deoxycitidine), is proving efficacious for hematological neoplasms especially at lower, less toxic, doses. Experimentally, high doses induce rapid DNA damage and cytotoxicity, but these may not explain the prolonged time to response seen in patients. Transient exposure of leukemic and solid tumor cells to clinically-relevant nanomolar doses, without causing immediate cytotoxicity or apoptosis, produces sustained reduced tumorigenicity, and for leukemia cells, diminished long-term self-renewal. These effects appear triggered by cellular reprogramming and include sustained decreases in promoter DNA methylation with associated gene re-expression, and anti-tumor changes in multiple key cellular regulatory pathways, most of which are high priority targets for pharmacologic anti-cancer strategies. Thus, low dose decitabine regimens appear to have broad applicability for cancer management. [Gene expression profiling] Leukemia cell lines Kasumi-1 and KG1A are treated with 10nM DAC during 72 hours and gene expression was assayed at day 3, 7 and 14 after the start of the treatment. Appropriate mock treated samples were used as control in each case. In addition, Kasumi-1 cells were also treated with a higher dose of DAC (500nM), 100nM ARA-C and 300 nM TSA, again controlled against mock treated Kasumi-1 cells, to separate dose and agent dependent effects. MCF7 was studied as an example of a solid tumor cell line. Therefore MCF7 cells were treated with 100nM DAC and results were assayed at day 1, day 3 and day 10. [Methylation profiling] The effects of the demethylating agent DAC were studied in the leukemia cell line Kasumi-1 over a 28 day time course. Intermediate time points were studied at days 3, 7, 14 and 21. These results were verfied in KG1A and KG1 leukemia cell lines, at one selected time point. The effects on one primary sample were also studied. Four normal leukemia samples (PL1, 2, 4 and 5) were used as general controls. The effect of DAC was compared to ARA-C, TSA. Both mock treated and day 3 DAC treated Kasumi-1 cells were repeated. These results were verified at one selected time point for the DAC treated MCF7 breast cancer cell line.
2012-03-21 | E-GEOD-20945 | biostudies-arrayexpress
Project description:Genome wide gene expression profiling of RKO cells with combination treatments of non-target siRNA or SRCAP siRNA and PBS or 1uM 5-Aza-CdR treatment. The sample treated with non target siRNA and PBS serves as control sample. Total RNA obtained from isolated RKO cells.
2013-01-01 | E-GEOD-26684 | biostudies-arrayexpress
Project description:Investigation of 5-aza-2'-cytidine and trichostatin A effect to gene expression of human LCLs. LCLs estabulished from patients with genetic dissease are commonly used for mRNA or protein analysis of disease related genes. However, ofen times the gene of interset is not expressed in LCL. Epigenetic modification could be overcome this problem. Expression array study with total RNA extracted from normal male derived LCLs with eight 60-mer probe per gene. 47633 exemplar genes representing a total of 63780 transcripts variants.
2012-01-27 | E-GEOD-35359 | biostudies-arrayexpress