Histone modifications have been implicated in stem cell maintenance and differentiation. We have analyzed genome-wide changes in gene expression and histone modifications during differentiation of multipotent human primary hematopoietic stem cells/progenitor cells (HSCs/HPCs) into erythrocyte precursors. Our data indicate that H3K4me1, H3K9me1, and H3K27me1 associate with enhancers of differentiation genes prior to their activation and correlate with basal expression, suggesting that these monomethylations are involved in the maintenance of activation potential required for differentiation. In addition, although the majority of genes associated with both H3K4me3 and H3K27me3 in HSCs/HPCs become silent and lose H3K4me3 after differentiation, those that lose H3K27me3 and become activated after differentiation are associated with increased levels of H2A.Z, H3K4me1, H3K9me1, H4K20me1, and RNA polymerase II in HSCs/HPCs. Thus, our data suggest that gene expression changes during differentiation are programmed by chromatin modifications present at the HSC/HPC stage and provide a resource for enhancer and promoter identification.
Chromatin signatures in multipotent human hematopoietic stem cells indicate the fate of bivalent genes during differentiation.
Specimen part
View SamplesThe zebrafish is a powerful model for the study of hematopoietic stem and progenitor cells (HSPC). We have developed a novel HSPC-specific transgenic line (Runx1+23:GFP). We have used this line in time-lapse live imaging studies to track the migration of HSPC during development. We have also performed a chemical genetic screen to find small molecules that modulate HSPC numbers during development. Treating embryos from 2-3 days post fertilization (2-3 dpf) then fixing for in situ staining with HSPC probes cmyb and runx1, we found the compound lycorine increased HSPC numbers. Applying this compound during time-lapse live imaging showed increased accumulation of Runx+ HSPC in the caudal hematopoietic tissue (CHT). Treatment from 2-3 dpf, then washing off the compound, had a sustained effect on the size of the HSPC with Runx+ numbers higher at 5 and 7 dpf.
Hematopoietic stem cell arrival triggers dynamic remodeling of the perivascular niche.
Specimen part, Treatment
View SamplesGenetically engineering Arabidopsis thaliana to express Isoprene Synthase (ISPS) leads to changes in expression of genes assoiated with many growth regulator signaling pathways and signaling networks involved in abiotic and biotic stress responses. Overall design: Arabidopsis thaliana transformed with a Eucalyptus globulus ISPS (line B2) and a line transformed with empty vector DNA (EV-B3), grown under unstressed growth conditions were subjected to RNA-Seq
Isoprene Acts as a Signaling Molecule in Gene Networks Important for Stress Responses and Plant Growth.
No sample metadata fields
View SamplesThe cure rate for childhood ALL has improved considerably in part because therapy is routinely tailored to the predicted risk of relapse. Various clinical and laboratory variables are used in current risk-stratification schemes, but many children who fail therapy lack adverse prognostic factors at initial diagnosis. Using gene expression analysis, we have identified genes and pathways in a NCI high-risk childhood B-precursor ALL cohort at diagnosis that may play a role in early blast regression as correlated with the Day 7 marrow status. We have also identified a 47-probeset signature (representing 41 unique genes) that was predictive of long term outcome in our dataset as well as three large independent datasets of childhood ALL treated on different protocols.
Gene expression signatures predictive of early response and outcome in high-risk childhood acute lymphoblastic leukemia: A Children's Oncology Group Study [corrected].
No sample metadata fields
View SamplesAlthough renal cell carcinoma (RCC) is the sixth-leading cause of cancer death, the molecular events leading to disease onset and progression are not well understood. Genomic profiling of clear cell RCC (cRCC) patients indicated that loss of a negative regulator of the Wnt pathway, secreted frizzled-related protein 1 (sFRP1), occurred in the majority of more than 100 patients tested. To our knowledge, this is the first report of loss of sFRP1 expression in patients diagnosed with cRCC; this loss occurs in early stage cRCC, suggesting that it may be an important early event in renal carcinogenesis. Genomic profiling of patient matched normal and cRCC tissues identified Wnt regulated genes to be aberrantly increased in cRCC tissues suggesting sFRP1 suppresses Wnt signaling in cRCC. In order to test the hypothesis that sFRP1 acts as a tumor suppressor in cRCC, we have stably expressed sFRP1 in cRCC cells. sFRP1 expression in cRCC cells resulted in decreased growth in cell culture, inhibition of anchorage-independent growth, and decreased tumor volume in a nude mouse model. Together these data suggest an important role for sFRP1 as a tumor suppressor in cRCC.
Secreted frizzled-related protein 1 loss contributes to tumor phenotype of clear cell renal cell carcinoma.
No sample metadata fields
View SamplesBackground: Resistance to platinum-based chemotherapy remains a major impediment in the treatment of serous epithelial ovarian cancer. The objective of this study was to use gene expression profiling to delineate major deregulated pathways and biomarkers associated with the development of intrinsic chemotherapy resistance upon exposure to standard first-line therapy for ovarian cancer. Methods: The study cohort comprised 28 patients divided into two groups based on their varying sensitivity to first-line chemotherapy using progression free survival (PFS) as a surrogate of response. All 28 patients had advanced stage, high-grade serous ovarian cancer, and were treated with the same standard platinum-based chemotherapy. Twelve patient tumors demonstrating relative resistance to platinum chemotherapy corresponding to shorter PFS (< eight months) were compared to sixteen tumors from platinum-sensitive patients (PFS > eighteen months). Whole transcriptome profiling was performed using a Affymetrix high-resolution microarray platform to permit global comparisons of gene expression profiles between tumors from the resistant group and the sensitive group. Results: Microarray data analysis revealed a set of 204 discriminating genes possessing expression levels, which could influence differential chemotherapy response between the two groups. Robust statistical testing was then performed which eliminated a dependence on the normalization algorithm employed, producing a restricted list of differentially regulated genes, and which found IGF1 to be the most strongly differentially expressed gene. Pathway analysis, based on the list of 204 genes, revealed enrichment in genes primarily involved in the IGF1/PI3K/NFB/ERK gene signalling networks. Conclusions: This study has identified pathway specific prognostic biomarkers possibly underlying a differential chemotherapy response in patients undergoing standard platinum-based treatment of serous epithelial ovarian cancer. Future studies to validate these markers are necessary to apply this knowledge to biomarker-based clinical trials.
Identification of the IGF1/PI3K/NF κB/ERK gene signalling networks associated with chemotherapy resistance and treatment response in high-grade serous epithelial ovarian cancer.
Specimen part
View SamplesSmall molecule BET bromodomain inhibitors (BETi) are actively being pursued in clinical trials for the treatment of a variety of cancers, however, the mechanisms of resistance to targeted BET protein inhibitors remain poorly understood. Using a novel mass spectrometry approach that globally measures kinase signaling at the proteomic level, we evaluated the response of the kinome to targeted BET inhibitor treatment in a panel of BRD4-dependent ovarian carcinoma (OC) cell lines. Despite initial inhibitory effects of BETi, OC cells acquired resistance following sustained treatment with the BETi, JQ1. Through application of Multiplexed Inhibitor Beads (MIBs) and mass spectrometry, we demonstrate that BETi resistance is mediated by adaptive kinome reprogramming, where activation of compensatory pro-survival kinase networks overcomes BET protein inhibition. Furthermore, drug combinations blocking these kinases may prevent or delay the development of drug resistance and enhance the efficacy of BET inhibitor therapy. Overall design: RNAseq was employed to identify changes in kinase RNA expression following short term (48h) or chronic (JQ1R) JQ1 treatment in three different ovarian cancer cell lines.
Resistance to BET Bromodomain Inhibitors Is Mediated by Kinome Reprogramming in Ovarian Cancer.
Cell line, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
The AIM2-like Receptors Are Dispensable for the Interferon Response to Intracellular DNA.
Treatment, Time
View SamplesAnalysis of ALR-deficient cells indicates that ALRs are not required for the IFN response to intracellular DNA. To explore whether AIM2-like receptors activated another innate signaling pathway upon
The AIM2-like Receptors Are Dispensable for the Interferon Response to Intracellular DNA.
Treatment, Time
View SamplesThis data was used to determine levels of BRCA1 and BRCA2 in primary human leukemia samples. Samples were determined to be high BRCA1 and/or BRCA2 or low BRCA1 and/or BRAC2.
Personalized synthetic lethality induced by targeting RAD52 in leukemias identified by gene mutation and expression profile.
No sample metadata fields
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