Substantial effort is currently devoted to identifying cancer-associated alterations using genomics. Here, we show that standard blood collection procedures rapidly change the transcriptional and post-transcriptional landscapes of hematopoietic cells, resulting in biased activation of specific biological pathways, up-regulation of pseudogenes, antisense RNAs, and unannotated coding isoforms, and RNA surveillance inhibition. Affected genes include common mutational targets and thousands of other genes participating in processes such as chromatin modification, RNA splicing, T and B cell activation, and NF-?B signaling. The majority of published leukemic transcriptomes exhibit signals of this incubation-induced dysregulation, explaining up to 40% of differences in gene expression and alternative splicing between leukemias and reference normal transcriptomes. The effects of sample processing are particularly evident in pan-cancer analyses. We provide biomarkers that detect prolonged incubation of individual samples, and show that keeping blood on ice markedly reduces changes to the transcriptome. In addition to highlighting the potentially confounding effects of technical artifacts in cancer genomics data, our study emphasizes the need to survey the diversity of normal as well as neoplastic cells when characterizing tumors. This study is complemented by GSE61410: transcriptomic profiling of bone marrow cells from healthy individuals. Overall design: Peripheral blood mononuclear cells (PBMCs) were isolated from four healthy individuals, following an ex vivo incubation of variable length at either room temperature or on ice. RNA transcriptomes were measured using the Illumina HiSeq.
Sample processing obscures cancer-specific alterations in leukemic transcriptomes.
No sample metadata fields
View SamplesExpression profiles of acute myeloid leukemia patient samples.
Identification of genes with abnormal expression changes in acute myeloid leukemia.
No sample metadata fields
View SamplesAcute myeloid leukemia (AML) is one of the most common and deadly forms of hematopoietic malignancies. We hypothesized that microarray studies could identify previously unrecognized expression changes that only occur only in AML blasts. We were particularly interested in those genes with increased expression in AML, believing that these genes may be potential therapeutic targets.
Identification of genes with abnormal expression changes in acute myeloid leukemia.
Sex, Disease
View SamplesV600E being the most common mutation in BRAF, leads to constitutive activation of the MAPK signaling pathway. The majority of V600E BRAF positive melanoma patients treated with the BRAF inhibitor vemurafenib showed initial good clinical responses but relapsed due to acquired resistance to the drug. The aim of the present study was to identify possible biomarkers associated with the emergence of drug resistant melanoma cells. To this end we analyzed the differential gene expression of vemurafenib-sensitive and vemurafenib resistant brain and lung metastasizing melanoma cells.
Vemurafenib resistance selects for highly malignant brain and lung-metastasizing melanoma cells.
Specimen part, Treatment
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Pluripotency-related, valproic acid (VPA)-induced genome-wide histone H3 lysine 9 (H3K9) acetylation patterns in embryonic stem cells.
Specimen part, Cell line, Treatment, Time
View SamplesGene expression profiles of E14 embryonic stem cells (ESCs) before and after treatment with low levels of the histone deacetylase (HDAC) inhibitors valproic acid (VPA) and sodium butyrate (NaBu).
Pluripotency-related, valproic acid (VPA)-induced genome-wide histone H3 lysine 9 (H3K9) acetylation patterns in embryonic stem cells.
Specimen part, Cell line, Treatment
View SamplesGene expression profiles of E14 embryonic stem cells (ESCs) before and after treatment with low levels of the histone deacetylase (HDAC) inhibitor valproic acid (VPA).
Pluripotency-related, valproic acid (VPA)-induced genome-wide histone H3 lysine 9 (H3K9) acetylation patterns in embryonic stem cells.
Specimen part, Cell line, Treatment
View SamplesCharacterization of differential gene expression due to cisplatin resistance in human ovarian cancer spheroids by microarray analysis.
Cisplatin Resistant Spheroids Model Clinically Relevant Survival Mechanisms in Ovarian Tumors.
Specimen part, Cell line
View SamplesThe effect of HMGN1 protein on gene expression of mouse ESC, NP and Neurons were investigated by comparing the transcriptome between Hmgn1+/+ and Hmgn1 -/- cells.
HMGN1 modulates nucleosome occupancy and DNase I hypersensitivity at the CpG island promoters of embryonic stem cells.
Specimen part
View SamplesRNAseq is performed (50bp single end reads) on SW480, HT-29, HCT-15, HCT-116, COLO 205, and COLO 320 cell lines after DMSO or JQ1 treatment Overall design: Examination of transcriptomic changes after JQ1 treatment
CCAT1 is an enhancer-templated RNA that predicts BET sensitivity in colorectal cancer.
No sample metadata fields
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