RNA-Seq has been increasingly used for the quantification and characterization of transcriptomes. The ongoing development of the technology promises the more accurate measurement of gene expression. However, its benefits over widely accepted microarray technologies have not been adequately assessed, especially in toxicogenomics studies. The goal of this study is to enhance the scientific community''s understanding of the advantages and challenges of RNA-Seq in the quantification of gene expression by comparing analysis results from RNA-Seq and microarray data on a toxicogenomics study. A typical toxicogenomics study design was used to compare the performance of an RNA-Seq approach (Illumina Genome Analyzer II) to a microarray-based approach (Affymetrix Rat Genome 230 2.0 arrays) for detecting differentially expressed genes (DEGs) in the kidneys of rats treated with aristolochic acid (AA), a carcinogenic and nephrotoxic chemical most notably used for weight loss. We studied the comparability of the RNA-Seq and microarray data in terms of absolute gene expression, gene expression patterns, differentially expressed genes, and biological interpretation. We found that RNA-Seq was more sensitive in detecting genes with low expression levels, while similar gene expression patterns were observed for both platforms. Moreover, although the overlap of the DEGs was only 40-50%, the biological interpretation was largely consistent between the RNA-Seq and microarray data. RNA-Seq maintained a consistent biological interpretation with time-tested microarray platforms while generating more sensitive results. However, there is clearly a need for future investigations to better understand the advantages and limitations of RNA-Seq in toxicogenomics studies and environmental health research. Overall design: Eight rats were randomly divided into two groups: four rats were administered with aristolochic acid (AA), and four rats were treated with the control vehicle. RNA samples were extracted from the kidney tissue of each rat and were independently assayed with both the NGS (Illumina Genome Analyzer II) and the microarray (Affymetrix Rat Genome 230 2.0) platforms. The RNA-Seq and microarray data were compared in terms of absolute gene expression, gene expression patterns, differentially expressed genes, and biological interpretation.
An investigation of biomarkers derived from legacy microarray data for their utility in the RNA-seq era.
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View SamplesOrganoids derived from human pluripotent stem cells recapitulate the early three-dimensional organization of human brain, but whether they establish the epigenomic and transcriptional programs essential for brain development is unknown. We compared epigenomic and gene regulatory features in cerebral organoids and human fetal brain, using genome-wide, base resolution DNA methylome and transcriptome sequencing. Transcriptomic dynamics in organoids faithfully modeled gene expression trajectories in early-to-mid human fetal brains. We found that early non-CG methylation accumulation at super-enhancers in both fetal brain and organoids marks forthcoming transcriptional repression in the fully developed brain. 74% of 35,627 demethylated regions identified during organoid differentiation overlapped with fetal brain regulatory elements. Interestingly, pericentromeric repeats showed widespread demethylation in multiple types of in vitro human neural differentiation models but not in fetal brain. Our study reveals that organoids recapitulate many epigenomic features of mid-fetal human brain and also identified novel non-CG methylation signatures of brain development. Overall design: MethylC-seq and RNA-seq of Cerebral Organoids differentiation
Cerebral Organoids Recapitulate Epigenomic Signatures of the Human Fetal Brain.
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View SamplesEngineered brain organoids (enCORs) exhibit reproducible neural differentiation and forebrain regionalization. Overall design: Comparison of transcriptomes from bioengineered micropatterned enCORs and spheroids at 20 days and 60 days
Guided self-organization and cortical plate formation in human brain organoids.
Specimen part, Subject, Time
View SamplesA phase I trial of a SRC kinase Inhibitor, dasatinib, in combination with paclitaxel and carboplatin in patients with advanced or recurrent ovarian cancer. Background: We conducted a phase I study of dasatinib, an oral SRC tyrosine kinase inhibitor, in combination with paclitaxel and carboplatin in advanced and recurrent epithelial ovarian cancer (EOC). Methods: The primary objective was to determine the maximum tolerated dose (MTD). Secondary objectives included toxicity, response rate (RR), pharmacokinetics and pharmacodynamics. Based on the 3+3 design, cohorts of 3-6 pts received paclitaxel 175 mg/m2 and carboplatin AUC 6 every three weeks with escalating doses of dasatinib (100, 120, 150 mg daily), followed by an 8 patient expansion cohort. Results: Twenty patients were enrolled between 06/07 and 12/09. The median age was 61 yrs (42-82) with a median of 2 prior regimens (0-6), and 71% had platinum-sensitive disease. There were 3-6 pts in each cohort, and 8 in the expansion cohort. Pharmacokinetics were observed over the first 2 cycles of therapy. One DLT was observed in the 100 mg dasatinib cohort (grade 3 myalgia. Other toxicities in all cycles included neutropenia (95% grade 3-4), thrombocytopenia (35% grade 3-4), and fatigue (10% grade 3). The RR was 45% (complete responses, 3/18(17%); partial responses, 5/18(28%)) and 56% (10/18) had stable disease. The PFS6-month actuarial estimate was 86%. The median PFS and OS were 7.8 and 16.2 months, respectively. Conclusions: Due to the high incidence of myelosuppression with subsequent cycles the recommended phase II dose is 150 mg daily of dasatinib in combination with paclitaxel and carboplatin. The combination was safe with evidence of clinical activity in advanced EOC.
A phase I trial of dasatinib, an SRC-family kinase inhibitor, in combination with paclitaxel and carboplatin in patients with advanced or recurrent ovarian cancer.
Subject
View SamplesThymic lymphomas develop spontaneously in LN3 mice. As for T-ALL in general, ex vivo LN3 lymphoma cells require stromal support to remain viable in culture. We found that primary stromal cells from thymic lymphomas, but not from wild-type thymi, support ex vivo lymphoma survival. By FACS sorting stromal populations, we identified dendritic cells in the tumor microenvironment as the cells capable of supporting lymphoma survival.
Endogenous dendritic cells from the tumor microenvironment support T-ALL growth via IGF1R activation.
Sex, Age, Specimen part, Disease, Disease stage
View SamplesThe comparative advantages of RNA-Seq and microarrays in transcriptome profiling were evaluated in the context of a comprehensive study design. Gene expression data from Illumina RNA-Seq and Affymetrix microarrays were obtained from livers of rats exposed to 27 agents that comprised of seven modes of action (MOAs); they were split into training and test sets and verified with real time PCR.
The concordance between RNA-seq and microarray data depends on chemical treatment and transcript abundance.
Sex, Specimen part
View SamplesCerebral organoids – three-dimensional cultures of human cerebral tissue derived from pluripotent stem cells – have emerged as models of human cortical development. However, the extent to which in vitro organoid systems recapitulate neural progenitor cell proliferation and neuronal differentiation programs observed in vivo remains unclear. Here we use single-cell RNA sequencing (scRNA-seq) to dissect and compare cell composition and progenitor-to-neuron lineage relationships in human cerebral organoids and fetal neocortex. Covariation network analysis using the fetal neocortex data reveals known and novel interactions among genes central to neural progenitor proliferation and neuronal differentiation. In the organoid, we detect diverse progenitors and differentiated cell types of neuronal and mesenchymal lineages, and identify cells that derived from regions resembling the fetal neocortex. We find that these organoid cortical cells use gene expression programs remarkably similar to those of the fetal tissue in order to organize into cerebral cortex-like regions. Our comparison of in vivo and in vitro cortical single cell transcriptomes illuminates the genetic features underlying human cortical development that can be studied in organoid cultures. Overall design: 734 single-cell transcriptomes from human fetal neocortex or human cerebral organoids from multiple time points were analyzed in this study. All single cell samples were processed on the microfluidic Fluidigm C1 platform and contain 92 external RNA spike-ins. Fetal neocortex data were generated at 12 weeks post conception (chip 1: 81 cells; chip 2: 83 cells) and 13 weeks post conception (62 cells). Cerebral organoid data were generated from dissociated whole organoids derived from induced pluripotent stem cell line 409B2 (iPSC 409B2) at 33 days (40 cells), 35 days (68 cells), 37 days (71 cells), 41 days (74 cells), and 65 days (80 cells) after the start of embryoid body culture. Cerebral organoid data were also generated from microdissected cortical-like regions from H9 embryonic stem cell derived organoids at 53 days (region 1, 48 cells; region 2, 48 cells) or from iPSC 409B2 organoids at 58 days (region 3, 43 cells; region 4, 36 cells).
Human cerebral organoids recapitulate gene expression programs of fetal neocortex development.
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View SamplesSignatures of Oncogenic Pathway Deregulation in Human Cancers.
Oncogenic pathway signatures in human cancers as a guide to targeted therapies.
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View SamplesSignatures of Oncogenic Pathway Deregulation in Human Cancers.
Oncogenic pathway signatures in human cancers as a guide to targeted therapies.
No sample metadata fields
View SamplesSignatures of Oncogenic Pathway Deregulation in Human Cancers.
Oncogenic pathway signatures in human cancers as a guide to targeted therapies.
No sample metadata fields
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