Project description:Using two independently derived murine BXH2 cell lines, Ara-C resistant derivatives were developed by exposure to increasing concentrations of Ara-C. Microarray analysis comparing the Ara-C resistant cells to their Ara-C sensitive parental cell lines identified potential genes involved in Ara-C resistance.
Project description:Using two independently derived murine BXH2 cell lines, Ara-C resistant derivatives were developed by exposure to increasing concentrations of Ara-C. Microarray analysis comparing the Ara-C resistant cells to their Ara-C sensitive parental cell lines identified potential genes involved in Ara-C resistance. Two highly Ara-C-resistant cell lines, B117H and B140H, were derived from Ara-C-sensitive parental cell lines, B117P and B140P. Variations in gene expression between these Ara-C-resistant and -sensitive sets were studied. Three replicates per cell line.
Project description:An RNA-seq study of altered gene expression and mutations in Ara-C resistant acute myeloid leukemia murine cell lines. The analysis of the RNA-seq data led to the identification of a large deletion within the Dck coding sequence of the B117H cell line, which produced an alternatively processed form of Dck mRNA. The RNA-seq analysis also identified the presence of an insertion mutation in Dck in the B140H cell line. The RNA-seq analysis also identified a number of significant expression changes which did not appear in a previous microarray analysis (GSE18322), as well as identified other mutations which may be contributing to Ara-C resistance. Two highly Ara-C resistant cell lines, B117H and B140H were derived from Ara-C sensitive parental cell lines, B117P and B140P. Variations in gene expression as well identification of acquired mutations between these Ara-C resistant/sensitive sets were studied using various RNA-seq analysis tools.
Project description:Wide inter-individual variation in terms of outcome and toxic side effects of treatment exist among patients with AML receiving chemotherapy with cytarabine (Ara-C) and daunorubicin (Dnr). Drug resistance and relapse are considered major causes of treatment failure. Gene expression profiling was undertaken to address possible mechanisms of Ara-C/Dnr resistance. Based on ex vivo Ara-C cytotoxicity at diagnosis, Ara-C sensitive (IC50 <3uM AraC) and Dnr sensitive samples (IC50 < 0.5 uM) (5 samples each) were included for microarray analysis. These were compared with the samples which were drug resistant ex vivo at diagnosis. Our microarray experiment resulted in indentifying differentially expressed genes under ex vivo Ara-C sensitive as well as Dnr sensitive samples compared to ex vivo Drug resistant samples.
Project description:Wide inter-individual variation in terms of outcome and toxic side effects of treatment exist among patients with AML receiving chemotherapy with cytarabine (Ara-C) and daunorubicin (Dnr). Drug resistance and relapse are considered major causes of treatment failure. Gene expression profiling was undertaken to address possible mechanisms of Ara-C/Dnr resistance. Based on ex vivo Ara-C cytotoxicity at diagnosis, Ara-C sensitive (IC50 <3uM AraC) and Dnr sensitive samples (IC50 < 0.5 uM) (5 samples each) were included for microarray analysis. These were compared with the samples which were drug resistant ex vivo at diagnosis. Our microarray experiment resulted in indentifying differentially expressed genes under ex vivo Ara-C sensitive as well as Dnr sensitive samples compared to ex vivo Drug resistant samples. One-color experiment,Organism: Homo sapiens, Custom Human Whole Genome 8x60k Array designed by Genotypic Technology Private Limited (AMADID: 27114), Labeling kit: Agilent Quick-Amp labeling Kit (p/n5190-0442)
Project description:An RNA-seq study of altered gene expression and mutations in Ara-C resistant acute myeloid leukemia murine cell lines. The analysis of the RNA-seq data led to the identification of a large deletion within the Dck coding sequence of the B117H cell line, which produced an alternatively processed form of Dck mRNA. The RNA-seq analysis also identified the presence of an insertion mutation in Dck in the B140H cell line. The RNA-seq analysis also identified a number of significant expression changes which did not appear in a previous microarray analysis (GSE18322), as well as identified other mutations which may be contributing to Ara-C resistance.
Project description:Title: Gene Expression in Ara-C Resistance in AML A microarray study of altered gene expression in acute myeloid leukemia cell lines Keywords: cell type comparison Keywords: Expression profiling by array
Project description:Following the discovery of BRD4 as a non-oncogene addiction target in acute myeloid leukemia (AML), BET inhibitors are being explored as promising therapeutic avenue in numerous cancers. While clinical trials have reported single-agent activity in advanced hematologic malignancies, mechanisms determining the response to BET inhibition remain poorly understood. To identify factors involved in primary and acquired BET resistance in leukemia, we performed a chromatin-focused shRNAmir screen in a sensitive MLL/AF9; NrasG12D‑driven AML model, and investigated dynamic transcriptional profiles in sensitive and resistant murine and human leukemias. Our screen reveals that suppression of the PRC2 complex, contrary to effects in other contexts, promotes BET resistance in AML. PRC2 suppression does not directly affect the regulation of Brd4-dependent transcripts, but facilitates the remodeling of regulatory pathways that restore the transcription of key targets such as Myc. Similarly, while BET inhibition triggers acute MYC repression in human leukemias regardless of their sensitivity, resistant leukemias are uniformly characterized by their ability to rapidly restore MYC transcription. This process involves the activation and recruitment of WNT signaling components, which compensate for the loss of BRD4 and drive resistance in various cancer models. Dynamic ChIP- and STARR-seq enhancer profiles reveal that BET-resistant states are characterized by remodeled regulatory landscapes, involving the activation of a focal MYC enhancer that recruits WNT machinery in response to BET inhibition. Together, our results identify and validate WNT signaling as a driver and candidate biomarker of primary and acquired BET resistance in leukemia, and implicate the rewiring of transcriptional programs as an important mechanism promoting resistance to BET inhibitors and, potentially, other chromatin-targeted therapies. RNA-Seq of DMSO- or JQ1-treated cancer cell lines; ChIP-seq for H3K36me3 and H3K27me3 in a leukemia cell line treated either with DMSO or JQ1, ChIP-seq for H3K27ac in resistant and sensitive mouse and human leukemia. Functional enhancer mapping (STARR-seq) in K-562 treated either with DMSO or JQ1.
Project description:Genome wide DNA methylation profiling of AML patient samples treated with PBS or DAC. The Illumina Infinium 450 Human DNA methylation was used to examine the methylation profile of 8 patient samples and 2 cell lines. Genome wide DNA methylation profiling of AML xenografts treated with either PBS control or with decitacine (DAC) alone, cytarabine (Ara-C) alone, DAC and Ara-C together (D+A), DAC followed by Ara-C (D/A) or with Ara-C followed by DAC (A/D).
Project description:Apoptosis is deregulated in most, if not all, cancers, including hematological malignancies. In this study, we wanted to test whether primary acute myeloid leukemia (AML) samples are sensitive for inhibitor of apoptosis (IAP) protein antagonist treatment in vitro, and which AML subgroup might profit most from such a novel therapeutic strategy. We treated diagnostic samples of 67 adult AML patients with either cytarabine (ara-C) or IAP antagonist BV6 and correlated sensitivity with clinical, cytogenetic and molecular markers, and expression levels of selected genes involved in apoptosis. Primary AML samples showed differential sensitivity to treatment with either ara-C (40% sensitive, 17% intermediate, 43% resistant) or BV6 (51% sensitive, 21% intermediate, 28% resistant). Notably, 69% of ara-C resistant samples showed a good to fair response to IAP inhibition. Furthermore, combination treatment of ara-C with BV6 showed additive effects in most samples. Differences in sensitivity to IAP antagonist treatment correlated with significantly elevated expression levels of TNF and lower levels of XIAP in BV6 sensitive samples, as well as with NPM1 mutations. Gene expression profiling pointed to apoptosis-related pathways, which were specifically induced by IAP inhibition in sensitive samples. Thus, our results suggest IAP inhibition as a potential novel therapeutic option in AML.