Background: The main bottleneck for genomic studies of tumors is the limited availability of fresh frozen (FF) samples collected from patients, coupled with comprehensive long-term clinical follow-up. This shortage could be alleviated by using existing large archives of routinely obtained and stored Formalin-Fixed Paraffin-Embedded (FFPE) tissues. However, since these samples are partially degraded, their RNA sequencing is technically challenging. Results: In an effort to establish a reliable and practical procedure, we compared three protocols for RNA sequencing using pairs of FF and FFPE samples, both taken from the same breast tumor. In contrast to previous studies, we compared the expression profiles obtained from the two matched sample types, using the same protocol for both. Three protocols were tested on low initial amounts of RNA, as little as 100 ng, to represent the possibly limited availability of clinical samples. For two of the three protocols tested, poly(A) selection (mRNA-seq) and ribosomal-depletion, the total gene expression profiles of matched FF and FFPE pairs were highly correlated. For both protocols, differential gene expression between two FFPE samples was in agreement with their matched FF samples. Notably, although expression levels of FFPE samples by mRNA-seq were mainly represented by the 3'-end of the transcript, they yielded very similar results to those obtained by ribosomal-depletion protocol, which produces uniform coverage across the transcript. Further, focusing on clinically relevant genes, we showed that the high correlation between expression levels persists at higher resolutions. Conclusions: Using the poly(A) protocol for FFPE exhibited, unexpectedly, similar efficiency to the ribosomal-depletion protocol, with the latter requiring much higher (2-3 fold) sequencing depth to compensate for the relative low fraction of reads mapped to the transcriptome. The results indicate that standard poly(A)-based RNA sequencing of archived FFPE samples is a reliable and cost-effective alternative for measuring mRNA-seq on FF samples. Expression profiling of FFPE samples by mRNA-seq can facilitate much needed extensive retrospective clinical genomic studies. Overall design: We perform an unbiased evaluation of RNA-seq of archived tumor tissues by comparing the same library preparation methods for both FF and FFPE matched tumor samples and for small amounts of total RNA starting material. We have 3 matched FF/FFPE tumor samples with a moderate archival time of about 4-5 years (T1=T3), and additional 3 FFPE tumor samples archived for more than 10 years (T4-T6). all samples were tested with two protocols: illumina Truseq RNA after poly(A) selection (mRNA-seq); and Truseq after ribosomal depletion (RiboZero). Several initial amounts of starting material was tested for eacg protocol.
mRNA-seq whole transcriptome profiling of fresh frozen versus archived fixed tissues.
Specimen part, Disease, Subject
View SamplesWe used microarrays to detail the global programme of gene expression in embryonic stem cells, early differentiated embrioid bodies and effect of short-term ATRA treatment.
Activation of retinoic acid receptor signaling coordinates lineage commitment of spontaneously differentiating mouse embryonic stem cells in embryoid bodies.
Cell line
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Genome wide mapping reveals PDE4B as an IL-2 induced STAT5 target gene in activated human PBMCs and lymphoid cancer cells.
Specimen part, Cell line
View SamplesIdentify IL-2 mediated genes in Kit225 cells.
Genome wide mapping reveals PDE4B as an IL-2 induced STAT5 target gene in activated human PBMCs and lymphoid cancer cells.
Specimen part, Cell line
View SamplesThis SuperSeries is composed of the SubSeries listed below.
STAT6 transcription factor is a facilitator of the nuclear receptor PPARγ-regulated gene expression in macrophages and dendritic cells.
Specimen part, Treatment, Subject, Time
View SamplesHuman CD14 positive monocytes were purified from healthy volunteers blood and cultured in vitro for 4, 12, 24, 72 hours. While culturing, macrophages were activated alternatively with interleukin-4 (IL-4 100 ng/ml) or classically with interferon-gamma (IFNg 100 ng/ml)+tumor necrosis factor (TNF 50 ng/ml) or left without activation. Simultaneously, macrophages were also treated with vehicle (DMSO:ethanol) or 1mM synthetic PPARg agonist, Rosiglitazone. We used Affymetrix microarrays (U133Plus 2.0) to analyze activation and PPARg-induced gene expression changes.
STAT6 transcription factor is a facilitator of the nuclear receptor PPARγ-regulated gene expression in macrophages and dendritic cells.
Specimen part, Treatment, Subject, Time
View SamplesC57Bl/6 wild-type and STAT6 KO mice were used to study PPARg and IL-4 signaling. Bone marrow of 3 mice per group was isolated and differentiated to macrophages with M-CSF (20 ng/ml). 20 ng/ml IL-4 was used to induce alternative macrophage activation and 1 uM Rosiglitazone (RSG) was used to activate PPARg. From each mouse 4 samples were generated: 1. M-CSF, 2. M-CSF+RSG, 3. IL-4 and 4. IL-4+RSG. All compounds were added throughout the whole differentiation process, and frech media was added every other day. Control cells were treated with vehicle (DMSO:ethanol). After 10 days, RNA was isolated and gene expression profiles were analyzed using Mouse Genome 430 2.0 microarrays from Affymetrix.
STAT6 transcription factor is a facilitator of the nuclear receptor PPARγ-regulated gene expression in macrophages and dendritic cells.
Specimen part, Treatment, Time
View SamplesConditional macrophage-specific PPARg knockout mice were generated on C57Bl/6 background by breeding PPARg fl/- (one allele is floxed, the other is null) and lysozyme Cre transgenic mice. PPARg and IL-4 signaling was analyzed on bone marrow-derived macrophages. Bone marrow of 3 mice per group was isolated and differentiated to macrophages with M-CSF (20 ng/ml). 20 ng/ml IL-4 was used to induce alternative macrophage activation and 1 uM Rosiglitazone (RSG) was used to activate PPARg. From each mouse 4 samples were generated: 1. M-CSF, 2. M-CSF+RSG, 3. IL-4 and 4. IL-4+RSG. All compounds were added throughout the whole differentiation process, and fresh media was added every other day. Control cells were treated with vehicle (DMSO:ethanol). After 10 days, RNA was isolated and gene expression profiles were analyzed using Mouse Genome 430 2.0 microarrays from Affymetrix.
STAT6 transcription factor is a facilitator of the nuclear receptor PPARγ-regulated gene expression in macrophages and dendritic cells.
Specimen part, Treatment, Time
View SamplesHuman CD14 positive monocytes were purified from healthy volunteers blood and cultured in vitro for 6 hours. While culturing, macrophages were activated alternatively with interleukin-4 (IL-4 100 ng/ml). Simultaneously, macrophages were also treated with vehicle (DMSO:ethanol) or 1uM synthetic PPARg agonist, Rosiglitazone. We used Affymetrix microarrays (U133Plus 2.0) to analyze activation and PPARg-induced gene expression changes.
STAT6 transcription factor is a facilitator of the nuclear receptor PPARγ-regulated gene expression in macrophages and dendritic cells.
Specimen part, Treatment, Subject, Time
View SamplesLeukemia is a complex malignancy with hundreds of distinct mutations associated with disease development. Studies have shown that oncogenes cooperate to promote leukemia transformation, however, the downstream effectors of this cooperation are largely unknown.
Gene sets identified with oncogene cooperativity analysis regulate in vivo growth and survival of leukemia stem cells.
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