KCL-22 is a chronic myeloid leukemia (CML) cell line derived from a patient in blast crisis phase and harbors the BCR-ABL translocation. The catalytic (ATP-competitive) BCR-ABL inhibitors imatinib and nilotinib have dramatically improved CML patient outcome, but the development of resistance remains a clinical challenge. The recent identification of allosteric BCR-ABL inhibitors, such as GNF-2, which target the enzyme by binding to the myristoyl pocket rather than catalytic site of ABL1, may provide a strategy to broadly overcome resistance to the class of ABL1 ATP competitive inhibitors. We therefore wanted to use the ClonTracer barcoding system to compare the clonal responses of KCL-22 to imatinib, nilotinib and GNF-2. RNA-seq was employed to characterize genetic alterations and gene expression signatures in the pooled cell populations resistant to BCR-ABL inhibitors as well as single clones showing differential response to the three inhibitors. Overall design: mRNA profiling of the subpopulations and single clones of human CML cell line KCL-22 that contribute to BCR-ABL inhibitor resistance
Studying clonal dynamics in response to cancer therapy using high-complexity barcoding.
No sample metadata fields
View SamplesThe non-small cell lung cancer (NSCLC) cell line HCC827 harbors an activating EGFR mutation (exon 19 deletion) that confers sensitivity to the FDA-approved EGFR inhibitor erlotinib. By applying the ClonTracer barcoding system, we were able to show the presence of pre-existing sub-populations in HCC827 that contribute to erlotinib resistance. Prior studies implicated that MET amplification confers resistance to erlotinib in this cell line. Therefore we examined the effects of the c-Met inhibitor crizotinib on the barcoded HCC827 population when treated either sequentially or simultaneously with both inhibitors. Despite the significant reduction in barcode complexity, the erlotinib/crizotinib combination treatment failed to eradicate all of the resistant clones implying the presence of an erlotinib/crizotinib dual resistant subpopulation. We performed transcriptome profiling (RNA-seq) to elucidate the potential resistance mechanisms of the dual resistant subpopulation in comparison to vehicle-treated or single agent erlotinib-resistant HCC827 cell populations as controls. Overall design: mRNA profiling of the subpopulations of human NSCLC cell line HCC827 that contribute to EGFR inhibitor erlotinib and MET inhibitor crizotinib resistance
Studying clonal dynamics in response to cancer therapy using high-complexity barcoding.
No sample metadata fields
View SamplesWe developed a computational framework that integrates chromosomal copy number and gene expression data for detecting aberrations that promote cancer progression. We demonstrate the utility of this framework using a melanoma dataset. Our analysis correctly identified known drivers of melanoma and predicted multiple novel tumor dependencies. Two dependencies, TBC1D16 and RAB27A, confirmed empirically, suggest that abnormal regulation of protein trafficking contributes to proliferation in melanoma. Together, these results demonstrate the ability of integrative Bayesian approaches to identify novel candidate drivers with biological, and possibly therapeutic, importance in cancer.
An integrated approach to uncover drivers of cancer.
Cell line
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Targeted resequencing identifies PTCH1 as a major contributor to ocular developmental anomalies and extends the SOX2 regulatory network.
Specimen part, Time
View SamplesSOX2 is the main gene involved in anophthalmia. In order to identify genes regulated by SOX2 transcription factors (genes that could be good candidates to also be involved in ocular development), we studied transcriptomic profiles of murine genetically modified stem cells overexpressing the RAX gene (CCE-Rx cells) after transfection by a siRNA against SOX2 or a scramble siRNA.
Targeted resequencing identifies PTCH1 as a major contributor to ocular developmental anomalies and extends the SOX2 regulatory network.
Specimen part, Time
View SamplesIn the urinary tract, smooth muscle (SM) is present in the renal pelvis, the ureter, the bladder and the urethra and plays a crucial role in the functional and structural integrity of these organs. In Tshz3 mutant ureters the myogenic program is not activated in the proximal region due to the absence of expression of myocardin (Myocd), a key regulator of SM differentiation. We set out to characterize TSHZ3-dependent mechanisms that participate to the process of ureteric smooth muscle cells (SMC) differentiation.
The tiptop/teashirt genes regulate cell differentiation and renal physiology in Drosophila.
Specimen part
View SamplesEBF1 is essential for B cell specification and commitment. To explore the dynamics of EBF1 initiated B cell programming, we performed EBF1 ChIP-seq, ATAC-seq, bisulfite-seq, RNA-seq and several histone ChIP-seq analyses at different stages of the transition from Ebf1-/- pre-pro-B to pro-B triggered by EBF1 restoration. We also performed Pax5 ChIP-seq in Ebf1-/- pre-pro-B cell and EBF1-restored pro-B cell to study the pioneering function of EBF1 that allows other transcription factors to access certain chromatin sites. Overall design: Time series RNA-Seq analysis during the differentiation from Ebf1-deficient pre-pro-B cell to EBF1-restored pro-B cell.
Dynamic EBF1 occupancy directs sequential epigenetic and transcriptional events in B-cell programming.
Subject
View SamplesEed (embryonic ectoderm development) is a core component of the Polycomb Repressive Complex 2 (PRC2) which catalyzes the methylation of histone H3 lysine 27 (H3K27). Trimethylated H3K27 (H3K27me3) can act as a signal for PRC1 recruitment in the process of gene silencing and chromatin condensation. Previous studies with Eed KO ESCs revealed a failure to down-regulate a limited list of pluripotency factors in differentiating ESCs. Our aim was to analyze the consequences of Eed KO for ESC differentiation. To this end we first analyzed ESC differentiation in the absence of Eed and employed in silico data to assess pluripotency gene expression and H3K27me3 patterns. We linked these data to expression analyses of wildtype and Eed KO ESCs. We observed that in wildtype ESCs a subset of pluripotency genes including Oct4, Nanog, Sox2 and Oct4 target genes progressively gain H3K27me3 during differentiation. These genes remain expressed in differentiating Eed KO ESCs. This suggests that the deregulation of a limited set of pluripotency factors impedes ESC differentiation. Global analyses of H3K27me3 and Oct4 ChIP-seq data indicate that in ESCs the binding of Oct4 to promoter regions is not a general predictor for PRC2-mediated silencing during differentiation. However, motif analyses suggest a binding of Oct4 together with Sox2 and Nanog at promoters of genes that are PRC2-dependently silenced during differentiation. In summary, our data further characterize Eed function in ESCs by showing that Eed/PRC2 is essential for the onset of ESC differentiation.
Polycomb protein EED is required for silencing of pluripotency genes upon ESC differentiation.
Specimen part, Cell line
View SamplesWe determined genome-wide nucleosome occupancy in mouse embryonic stem cells and their neural progenitor and embryonic fibroblast counterparts to assess features associated with nucleosome positioning during lineage commitment. Cell type and protein specific binding preferences of transcription factors to sites with either low (e.g. Myc, Klf4, Zfx) or high (e.g. Nanog, Oct4 and Sox2) nucleosome occupancy as well as complex patterns for CTCF were identified. Nucleosome depleted regions around transcription start and termination sites were broad and more pronounced for active genes, with distinct patterns for promoters classified according to their CpG-content or histone methylation marks. Throughout the genome nucleosome occupancy was dependent on the presence of certain histone methylation or acetylation modifications. In addition, the average nucleosome-repeat length increased during differentiation by 5-7 base pairs, with local variations for specific genomic regions. Our results reveal regulatory mechanisms of cell differentiation acting through nucleosome repositioning. Overall design: The Total RNA from ESCs, NPCs and MEFs was extracted by guanidinisothiocyanat/phenol extraction with the Trifast kit (Peqlab). Total RNA preparations were treated with DNase I, phenol/chloroform extracted and precipitated before further processing. RNAs were depleted of 5S, 5.8S, 18S and 28S rRNAs using the Human/Mouse/Rat Ribo-Zero rRNA Removal Kit (Epicentre) according to the manufacturer’s protocol. After rRNA depletion, RNAs were fragmented with a kit from Ambion. Libraries for Solexa sequencing were generated according to the standard Illumina protocol that comprised first strand cDNA synthesis, second strand cDNA synthesis, end repair, addition of a single A base, and adapter ligation. Sequencing was performed on the Illumina GAIIx (replicate 1) and Illumina HiSeq 2000 (replicate 2) platforms at the sequencing core facilities of the BioQuant in Heidelberg, Germany. RNA reads were aligned with TopHat. Further expression analysis was with the Genomatix software suite (Genomatix, Munich, Germany) and the Eldorado gene annotation. For each transcript a normalized expression value was calculated from the read distribution that accounts for the length differences using the program DEseq for the analysis of differential expression.
Genome-wide nucleosome positioning during embryonic stem cell development.
Specimen part, Cell line, Subject
View SamplesRNA expression in WT and jhd2? cells in various nutritional sources Overall design: Strand-specific total RNA was sequenced (Illumina stranded TruSeq, with dUTP second strand-incorporation) from wildtype and mutants cells, in biological replicates, normalized by RNA spike-in controls
Mitochondrial control through nutritionally regulated global histone H3 lysine-4 demethylation.
Cell line, Subject
View Samples