Messenger RNA levels in eukaryotes are balanced by two consecutive regulatory layers. Primary, transcriptional regulation at the level of chromatin and secondary, post-transcriptional regulation of the initial transcript in the cytoplasm. Each layer is individually studied in mechanistic detail, while integration of both processes is required to quantify the individual contribution to steady-state RNA levels. Here we show that chromatin features are sufficient to model transcription rate but with different sensitivities in dividing versus post mitotic cells. In both cases chromatin derived transcript levels explains over 80% of variance in measured RNA level enabling to separate transcription from different post-transcriptional processes. By further inclusion of measurements of mRNA half-life and micro RNA expression data we identify a low quantitative contribution of RNA decay by either micro RNA or general differential turnover to final mRNA levels. Together this establishes a chromatin based quantitative model for the contribution of transcriptional and posttranscriptional processes to steady-state levels of messenger RNA.
Chromatin measurements reveal contributions of synthesis and decay to steady-state mRNA levels.
Specimen part, Disease, Treatment, Time
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Target genes of Topoisomerase IIβ regulate neuronal survival and are defined by their chromatin state.
Specimen part, Treatment
View SamplesExpression profiling of from Top2 knokout and ICRF-193 treated neurons reveals a significant number of genes that are transcriptionally deregulated
Target genes of Topoisomerase IIβ regulate neuronal survival and are defined by their chromatin state.
Specimen part, Treatment
View SamplesExpession data from L1-L2 stage nematodes (C. elegans), wild type and four mutants (alg-1, zfp-1, rde-4, lin-35).
RNA interference and retinoblastoma-related genes are required for repression of endogenous siRNA targets in Caenorhabditis elegans.
No sample metadata fields
View SamplesThis Series represents the gene expression profiles of patients with multiple myeloma who have been treated previously. In brief, Total Therapy 6 (TT6) is an open label phase 2 protocol for patients with symptomatic multiple myeloma, who had been treated with more than one cycle of prior therapy excluding autologous hematopoietic stem cell transplant. This protocol was approved by the institutional review board on March 25, 2009 (IRB#108053). The TT6 treatment regimen consists of induction therapy with Melphalan/Bortezomib/Thalidomide/Dexamethasone/Cisplatin/Doxorubicin/Cyclophosphamide/Etoposide (M-VTD-PACE) followed by a high dose M-VTD-PACE based tandem transplant. Maintenance therapy consists of Bortezomib/Lenalidomide/Dexamethasone alternating with Borteomib/Melphalan/Dexamethasone every months for 3 years.
Five gene probes carry most of the discriminatory power of the 70-gene risk model in multiple myeloma.
Specimen part, Disease, Treatment
View SamplesEwing sarcomas are characterized by the presence of EWS/ETS fusion genes in the absence of other recurrent genetic alterations and mechanisms of tumor heterogeneity that contribute to disease progression remain unclear. Mutations in the Wnt/beta-catenin pathway are rare in Ewing sarcoma but the Wnt pathway modulator LGR5 is often highly expressed, suggesting a potential role for the axis in tumor pathogenesis. We evaluated beta-catenin and LGR5 expression in Ewing sarcoma cell lines and tumors and noted marked intra- and inter-tumor heterogeneity. Tumors with evidence of active Wnt/beta-catenin signaling were associated with increased incidence of tumor relapse and worse overall survival. Paradoxically, RNA sequencing revealed a marked antagonism of EWS/ETS transcriptional activity in Wnt/beta-catenin activated tumor cells. Consistent with this, Wnt/beta-catenin activated cells displayed a phenotype that was reminiscent of Ewing sarcoma cells with partial EWS/ETS loss of function. Specifically, activation of Wnt/beta-catenin induced alterations to the actin cytoskeleton, acquisition of a migratory phenotype and up regulation of EWS/ETS-repressed genes. Notably, activation of Wnt/beta-catenin signaling led to marked induction of tenascin C (TNC), an established promoter of cancer metastasis, and an EWS/ETS-repressed target gene. Loss of TNC function in Ewing sarcoma cells profoundly inhibited their migratory and metastatic potential. Our studies reveal that heterogeneous activation of Wnt/beta-catenin signaling in subpopulations of tumor cells contributes to phenotypic heterogeneity and disease progression in Ewing sarcoma. Significantly, this is mediated, at least in part, by inhibition of EWS/ETS fusion protein function that results in de-repression of metastasis-associated gene programs. Overall design: Differential gene expression in highly Wnt-responsive cells.
Activation of Wnt/β-Catenin in Ewing Sarcoma Cells Antagonizes EWS/ETS Function and Promotes Phenotypic Transition to More Metastatic Cell States.
No sample metadata fields
View SamplesMesenchymal stem cells (MSCs) are an essential component of the bone marrow (BM) microenvironment and have shown to support cancer evolution in multiple myeloma (MM). Despite the increasing evidence that MM MSCs differ from their healthy counterparts, little knowledge exists as to whether MSCs independently influence disease outcome. The aim of the present study was to determine the importance of MSCs in disease progression and outcome in MM.
The Pattern of Mesenchymal Stem Cell Expression Is an Independent Marker of Outcome in Multiple Myeloma.
Specimen part, Disease, Subject
View SamplesInducible co-stimulator (ICOS) interaction with its ligand (ICOSL) is involved in several T cell effector functions. While blockade of ICOS:ICOSL interaction in chronic graft versus host disease (GVHD) seems benefi cial, results for acute GVHD remain controversial. To further elucidate its role in acute GVHD, C57BL / 6 mice were lethally irradiated and reconstituted with allogeneic spleen cells in the absence or presence of ICOSL-blocking mAb. Mice reconstituted with allogeneic spleen cells experienced severe GVHD and died untreated within 6 9 days after transplantation. Mice treated with an anti-ICOSL mAb starting from day 3 after transplantation gained weight again and survived for at least additional 12 days, although the treatment was already stopped at day 11 after transplantation. In contrast, the anti-ICOSL treatment starting from day 0 did not prevent GVHD. The diff erence between therapeutic (day 3) and prophylactic (day 0) anti-ICOSL treatment was independent of CD25 + CD4 + regulatory T cells since their depletion did not abrogate the therapeutic eff ect of ICOSL blockade. Microarray analysis revealed IFN- and chemokine up-regulation in spleen cells of prophylactically treated mice, emphasizing kinetic dependence of acute GVHD modulation via blockade of ICOS:ICOSL interaction.
Only therapeutic ICOS:ICOSL blockade alleviates acute graft versus host disease.
Sex, Specimen part
View SamplesPurpose: Because dexamethasone remains a key component of myeloma therapy, we wished to examine the correlation of baseline and relapse expression levels of the glucocorticoid receptor gene NR3C1 with other clinical features. Experimental Design: We investigated the clinical impact of gene expression profiling (GEP)derived expression levels of NR3C1 in 351 patients with GEP data available at baseline and in 130 with data available at relapse, among 668 subjects accrued to Total Therapy 2 (TT2).
Thalidomide in total therapy 2 overcomes inferior prognosis of myeloma with low expression of the glucocorticoid receptor gene NR3C1.
Disease, Treatment
View SamplesAlthough several markers have been associated with the characterization of regulatory T cells (Treg) and their function, no studies have investigated the dynamics of their phenotype during infection. Since the necessity of Treg to control immunopathology has been demonstrated, we used the chronic helminth infection model S. mansoni to address the impact on the Treg gene repertoire. Before gene expression profiling we first chose to study the localization and antigen-specific suppressive nature of classically defined Treg during infection. Presence of Foxp3+ cells were found especially in the periphery of granulomas and isolated CD4+CD25hiFoxp3+ Treg from infected mice blocked IFN-gamma and IL-10 cytokine secretion from infected CD4+CD25- effector T cells (Teff). Furthermore the gene expression patterns of Treg and Teff showed that in total 474 genes were significantly regulated during chronic schistosomiasis. Upon k-means clustering we identified genes exclusively regulated in all four populations including Foxp3, CD103, GITR, OX40 and CTLA-4: classical Treg markers. During infection however, several non-classical genes were up-regulated solely within the Treg population such as Slpi, Gzmb, Mt1, Fabp5, Nfil3, Socs2, Gpr177 and Klrg1. Using RT-PCR we confirmed aspects of the microarray data and in addition showed that the expression profile of Treg from S. mansoni-infected mice is simultaneously unique and comparative with Treg derived from other infections
Pronounced phenotype in activated regulatory T cells during a chronic helminth infection.
Specimen part
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