As part of a larger effort to provide proof-of-concept in vitro only risk assessments, we have developed a suite of high throughput assays for key readouts in the p53 DNA damage response toxicity pathway: DSB DNA damage (p-H2AX), permanent chromosomal damage (micronuclei; MN), p53 activation, p53 transcriptional activity, and cell fate (cell cycle arrest, apoptosis,MN). Dose-response studies were performed with these protein and cell fate assays, together with whole genome transcriptomics, for three prototype chemicals: etoposide (ETP), quercetin (QUE) and methyl methanesulfonate (MMS). Data were collected in a human cell line expressing wild-type p53 (HT1080) and results were confirmed in a second p53 competent cell line (HCT 116). At chemical concentrations causing similar increases in p53 protein expression, p53-mediated protein expression and cellular processes showed substantial chemical-specific differences. These chemical-specific differences in the p53 transcriptional response appear to be determined by augmentation of the p53 response by co-regulators. More importantly, dose-response data for each of the chemicals indicates that the p53 transcriptional response does not prevent MN induction at low concentrations. In fact, the no observed effect levels (NOELs) and benchmark doses (BMDs) for MN induction were less than or equal to those for p53-mediated gene transcription regardless of the test chemical, indicating that p53s post-translational responses may be more important than transcriptional activation in the response to low dose DNA damage. This effort demonstrates the process of defining key assays required for a pathway-based, in vitro-only risk assessment, using the p53-mediated DNA damage response pathway as a prototype.
Profiling dose-dependent activation of p53-mediated signaling pathways by chemicals with distinct mechanisms of DNA damage.
Specimen part, Cell line
View SamplesCompound Kushen Injection (CKI) has been clinically used in China for over 15 years to treat various types of solid tumours. However, because such Traditional Chinese Medicine (TCM) preparations are complex mixtures of plant secondary metabolites, it is essential to explore their underlying molecular mechanisms in a systematic fashion. We have used the MCF-7 breast cancer cell line as an initial in vitro model to identify CKI induced changes in gene expression. Cells were treated with CKI for 24 and 48 hours at two concentrations (1.0 and 2.0 mg/mL), and 5-Fluorouracil (5-FU) was used to treat cells as a positive control. Cell proliferation and apoptosis activity were measured with XTT and Caspase-3 assays respectively. Transcriptome data of cells treated with CKI or 5-FU for 24 and 48 hours were acquired using high-throughput Illumina RNA-seq technology. In this report we show that CKI inhibited MCF-7 cell proliferation and induced apoptosis in a dose-dependent fashion. We integrated and applied a series of transcriptome analysis methods, including gene differential expression analysis, pathway over-representation analysis, de novo identification of long non-coding RNAs (lncRNA) as well as co-expression network reconstruction, to identify candidate anti-cancer molecular mechanisms of CKI. Multiple pathways were perturbed and the cell cycle was identified as the potential primary target pathway of CKI in MCF-7 cells. CKI may also induce apoptosis in MCF-7 cells via a p53 independent mechanism. In addition, we identified novel lncRNAs and showed that many of them might be expressed as a response to CKI treatment. Overall, we have comprehensively investigated the utility of transcriptome analysis with high-throughput sequencing to characterise the molecular response of cancer cells to a TCM drug, and provided a practical guideline for future molecular studies of TCM. Overall design: High-depth paired-end RNA-seq from MCF-7 cell line. Each sample contains 3 biological replicates.
Identification of candidate anti-cancer molecular mechanisms of Compound Kushen Injection using functional genomics.
No sample metadata fields
View SamplesLongitudinal analysis of monocyte gene expressions patterns before and after cessation of HAART: understanding the impact of HIV viremia on the monocyte tranascritome. We used microarrays to detail the global program of gene expression underlying defects in monocytes from HIV infected patients during viremia..
Diminished production of monocyte proinflammatory cytokines during human immunodeficiency virus viremia is mediated by type I interferons.
No sample metadata fields
View SamplesOsteoarthritis (OA) is a common degenerative disease of the joint. Data from our lab indicates that Hedgehog (Hh) signaling is activated in human OA and murine models of OA (Lin et al., 2009, Nature Medicine). To identify Hh target genes, microarray analyses were performed to detect changes in gene expression when the Hh pathway was inhibited in human OA cartilage samples.
Regulation of Cholesterol Homeostasis by Hedgehog Signaling in Osteoarthritic Cartilage.
Sex, Specimen part, Treatment
View SamplesThe susceptibility of macrophages to HIV-1 infection is modulated during monocyte differentiation. IL-27 is an anti-HIV cytokine that also modulates monocyte activation. Here, we present new evidence that IL-27 promotes monocyte differentiation into macrophages that are non-permissive for HIV-1 infection.
IL-27 inhibits HIV-1 infection in human macrophages by down-regulating host factor SPTBN1 during monocyte to macrophage differentiation.
Specimen part, Treatment
View SamplesPQBP1 is a highly conserved protein closely related to neurodegenerative disorders. We identified PQBP1 as an important alternative splicing effector necessary for maintaining normal neuron functions in the brain. In order to explore PQBP1''s functions in alternative splicing regulation and neuronal activities, we systematically profiled the alternative splicing targets of PQBP1 in mouse embryonic cortical neurons by RNA-seq. The mRNAs whose alternative splicing are affected by PQBP1 showed tissue-specific functional enrichment especially in neurite outgrowth, with strong Gene Ontology (GO) enrichments for neuron projection development/morphogenesis, dendrite development and axonogenesis. PQBP1''s alternative splicing targets are also functionally enriched in RNA splicing, chromatin modification, and ARF signal transduction. Overall design: We applied RNA-seq to compare the transcriptomes of mock and PQBP1 knockdown mouse embryonic cortical neuron samples.
PQBP1, a factor linked to intellectual disability, affects alternative splicing associated with neurite outgrowth.
Cell line, Subject
View SamplesLoss of the tumor suppressor CHD5 frequently occurs during neuroblastoma progression.
The chromatin remodeling factor CHD5 is a transcriptional repressor of WEE1.
Specimen part, Cell line
View SamplesWe report the application of ultrashort metabolic labeling of RNA for high-throughput profiling of RNA processing in Drosophila S2 cells. Overall design: Examination of 3 different labeling timepoints in Drosophila S2 cells.
The kinetics of pre-mRNA splicing in the <i>Drosophila</i> genome and the influence of gene architecture.
Cell line, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Pausing of RNA polymerase II disrupts DNA-specified nucleosome organization to enable precise gene regulation.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Expression of three topologically distinct membrane proteins elicits unique stress response pathways in the yeast Saccharomyces cerevisiae.
No sample metadata fields
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