Decitabine alters DNA methylation in AML patients
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Dietmar Pfeifer
PROVIDER: E-MEXP-3737 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:array-based analysis of genome-wide DNA methylation changes induced by the demethylating drugs azacytidine and decitabine on HCT116 cells for 24 hours
2010-07-01 | E-MTAB-210 | biostudies-arrayexpress
Project description:Acute myeloid leukemia (AML), and other myeloid malignancies, are frequently treated with hypomethylating agents like decitabine. Alterations in the epigenome, induced by decitabine, are likely to result in gene expression changes. The effects of decitabine have not been systemically studied using primary AML samples. We cultured 18 different primary AML samples for 7 days, the last 3 days of which included 100 nM decitabine (DAC) or 100 nm cytarabine (AraC). We hypothesized that decitabine treatment would result in detectable and consistent gene expression changes. For comparison, we also analyzed mRNA from cells treated with DMSO control (mock) and mRNA from uncultured cells taken at the time of diagnosis.
2012-12-18 | E-GEOD-40442 | biostudies-arrayexpress
Project description:Our study had shown that DAC treatment enhanced immunogenecity of EL4 cells. To explore the mechanisms of DAC-induced tumor immunity, we carried out cDNA microarray analyses to compare the differential expression of genes between DAC and PBS treated EL4 cells. Two-condition experiment, PBS treated EL4 vs. Decitabine treated EL4 cells. Biological replicates: 3 PBS treated, 3 Decitabine treated, independently treatment and harvested. One replicate per array.
2013-02-15 | E-GEOD-38473 | 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: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 gene expression profiling method on HGU133plus2 array, we identified a total of 1370 genes showing significant gene expression changes with 687 genes going up and 683 genes going down in the resistant (cp70) versus sensitive cell lines (A2780) by Rank Product (FDR<5%). Combining expression profiling with methylation profiling data we found out of 245 hypermethylated and down-regulated genes in the resistant cell line, 41 genes were up-regulated following Decitabine treatment alone, 45 genes up-regulated following combined treatment of Decitabine and PXD101, and only 10 genes up-regulated following PXD101 treatment alone. Altogether we found a small set of genes as being 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. Gene expression profiling was obtained from A2780, and CP70 before and after Decitabine and/or PXD101 treatment. Each sample have biological triplicates. Using Rank Product package in R (version 2.10.1), differentially expressed genes with FDR<5% were identified.
2011-12-20 | E-GEOD-28646 | biostudies-arrayexpress
Project description:Comparing gene profile of ST88 cells treated with 75µM FTS in 5% serum to those of control
2011-04-01 | E-MEXP-2766 | biostudies-arrayexpress
Project description:Purpose: We aimed to investigate the effect of several anti-leukemia drugs in combination with decitabine (DAC) on the proliferation of myeloid leukemia cells in vitro and in vivo, to select the most efficient combination group and explore associated mechanisms of these combination therapies. Experimental Design: After comparing with five anti-leukemia drugs in several different kinds of cell lines, the combination effect of idarubicin (IDA) with DAC was best. In vivo, by using microPET, TUNEL, and transmission electron microscopy, the inhibitory effects obtained by sequentially combining DAC with IDA, evidenced by evaluating tumor cell proliferation and cell apoptosis. Molecular studies were conducted using gene chip, which was used to explore associated pathways, and real-time quantitative reverse transcription-PCR, western blot and immunohistochemistry (IHC), used to assess regulation of Wnt/β-catenin pathway. Results: The sequential combination of DAC and IDA showed synergistic induction of cell death in U937, HEL, SKM-1 and cells isolated from AML patients. Importantly, the inhibition of tumor growth in the sequential combination group was found to be significantly higher than that of single drug group or control group in vivo. Moreover, sequential treatment with DAC and IDA induced apoptosis and depression of the Wnt/β-catenin pathway in both culture and animal studies. Conclusions: Our findings showed that sequentially combining decitabine with idarubicin had a synergistic anti-leukemia effect. These findings were attributed to demethylation of Wnt pathway inhibitors and downregulation of Wnt pathway nuclear targets observed in vitro and in vivo. After comparing with five anti-leukemia drugs in several different kinds of cell lines, the combination effect of idarubicin (IDA) with DAC was best. In vivo, by using microPET, TUNEL, and transmission electron microscopy, the inhibitory effects obtained by sequentially combining DAC with IDA, evidenced by evaluating tumor cell proliferation and cell apoptosis. Molecular studies were conducted using gene chip, which was used to explore associated pathways, and real-time quantitative reverse transcription-PCR, western blot and immunohistochemistry (IHC), used to assess regulation of Wnt/β-catenin pathway.
2014-02-13 | E-GEOD-54918 | biostudies-arrayexpress
Project description:The c-Myb transcription factor is highly expressed in immature hematopoietic cells and down-regulated during differentiation. To define the role of c-Myb during the terminal differentiation of hematopoietic precursors, we studied the effects of its silencing in human primary CD14-myeloblasts, which maintain a granulo-monocyte differentiation bipotentiality. c-Myb-silenced myeloblasts were blocked in the G1 phase of the cell cycle at 24 hours post-nucleofection and subsequently were forced towards macrophage differentiation, as demonstrated by immunophenotypic and morphological analysis. Indeed, c-Myb-silenced CD14- cells differentiate to macrophage even after the treatment with ATRA 10-6 M, demonstrating that the c-Myb knockdown strongly impairs the ability of myeloblasts to differentiate to granulocytes. Gene expression profiling of c-Myb-silenced CD14- cells identified some potential c-Myb targets that can account for these effects. To maximize siRNA transfection efficiency, we utilized the NucleofectorTM technology (Amaxa). CD14- cells were transfected with a mixture of 3 siRNAs targeting c-Myb mRNA, with a non-targeting siRNA as a negative control (NegCTR) and without siRNA (MOCK). c-Myb siRNAs were transfected at days 1 to 3 after the CD14- myeloblasts purification based on the observation that this timing represented a phase of phisiological increase in c-Myb expression in myeloblasts. Western Blot analysis at 24 hours post-nucleofection demonstrated the c-Myb protein knockdown in MYBsiRNA CD14- cells as compared with control samples (MOCK, NegCTR).
2010-07-14 | E-GEOD-21943 | biostudies-arrayexpress
Project description:Androgenic steroids are increasingly used for hormone therapy of postmenopausal women and abused as life style drugs and for doping purposes, though knowledge about associated health risks in females is very limited. In order to understand more about short- and long-term androgen effects on a molecular level, we have analyzed hepatic gene expression in female C57BL/6 mice immediately after subcutaneous treatment with testosterone for 3 weeks and after 12 weeks hormone withdrawal using Affymetrix array technology and quantitative real-time RT-PCR. Among about 14,000 genes examined, 48 were up- and 65 genes were downregulated by testosterone after 3-weeks treatment and about 50% of these changes persisted even 12 weeks after testostrone withdrawal. In addition to obvious risks such as induction of hepatocellular carcinomas and virilization of liver metabolism, testosterone induced a series of changes, as e.g. dysregulation of hepatic gene expression due to incomplete conversion of female to male phenotype â in particular downregulation of cytochrom P450 isoforms and sulfotransferases. As a long-term testosterone effect, transcripts emerged in the liver that are normally specific for the exocine pancreas including amylase 2, ribonuclease 1, and several trypsin-, chymotrypsin-, and elastase-like proteases. This transdifferentiation of hepatic to exocrine pancreatic tissue indicates that testosterone can initiate long-lasting differentiation programs, which â once induced â progress even after androgen withdrawal. This may have far-reaching consequences difficult to foresee implying long-term hazards of testosterone-treatment for female health that have not been taken into account yet. Mice were treated with testosterone or sesame oil (vehicle) for three weeks twice a week. Gene expression in the liver was analyzed either directly after treatment or after three weeks of hormone/vehicle withdrawal. For each of these four groups, three individual mice were used as biological replicates.
2010-03-03 | E-GEOD-13388 | biostudies-arrayexpress
Project description:This SuperSeries is composed of the following subset Series: GSE28646: Gene expression profiling in A2780, CP70 and CP70 following Decitabine and/or PXD101 treatment GSE28647: Genome-wide methylation profiling identifies candidate DNA methylation drivers of acquired cisplatin resistance in ovarian cancer. Refer to individual Series
2011-12-20 | E-GEOD-28648 | biostudies-arrayexpress