Background: Information on the carcinogenic potential of chemicals is only availably for High Production Volume products. There is however, a pressing need for alternative methods allowing for the chronic toxicity of substances, including carcinogenicity, to be detected earlier and more reliably. Here we applied advanced genomics to a cellular transformation assay to identify gene signatures useful for the prediction of risk for carcinogenicity. Methods: Genome wide gene expression analysis and qRT-PCR were applied to untransformed and transformed Balb/c 3T3 cells that exposed to 2, 4-diaminotoluene (DAT), benzo(a)pyrene (BaP), 2-Acetylaminoflourene (AAF) and 3-methycholanthrene (MCA) for 24h and 120h, at different concentrations, respectively. Furthermore, various bioinformatics tools were used to identify gene signatures predicting for the carcinogenic risk. Results: Bioinformatics analysis revealed distinct datasets for the individual chemicals tested while the number of significantly regulated genes increased with ascending treatment concentration of the cell cultures. Filtering of the data revealed a common gene signature that comprised of 13 genes whose regulation in cancer tissue has already been established. Strikingly, this gene signature was already identified prior to cell transformation therefore confirming the predictive power of this gene signature in identifying carcinogenic risks of chemicals. Comparison of fold changes determined by microarray analysis and qRT-PCR were in good agreement. Conclusion: Our data describes selective and commonly regulated carcinogenic pathways observed in an easy to use in vitro carcinogenicity assay. Here we defined a set of genes which can serve as a simply assay to predict the risk for carcinogenicity by use of an alternative in vitro testing strategy.
Toxicogenomics applied to in vitro carcinogenicity testing with Balb/c 3T3 cells revealed a gene signature predictive of chemical carcinogens.
Cell line, Treatment, Time
View SamplesDNA microarray analysis was performed with mouse multipotent adult germline stem cells (maGSCs) and embryonic stem cells (ESCs) from different genetic backgrounds cultured under standard ESC culture conditions and under differentiation-promoting conditions by the withdrawal of Leukemia Inhibitory Factor (LIF) and treatment with Retinoic Acid (RA). The analyzed undifferentiated cell lines are very similar based on their global gene expression pattern and show 97-99% identity dependent on the analyzed background. Only 621 genes are differentially expressed in cells derived from mouse 129SV-background, and 72 genes show differences in expression in cells generated from transgenic Stra8-EGFP/Rosa26-LacZ-background. Both maGSCs and ESCs express the same genes involved in the regulation of pluripotency, and even show no differences in the expression level of these genes. When comparing maGSCs with previously published signature genes of other pluripotent cell lines we could find that maGSCs share a very similar gene expression pattern with embryonic germ cells (EGCs). Also after differentiation of maGSCs and ESCs the transcriptomes of the cell lines are nearly identical which suggests that both cell types differentiate spontaneously in a very similar way. This is the first study comparing ESCs and a pluripotent cell line derived from an adult organism (maGSCs) on transcriptome level.
Pluripotent embryonic stem cells and multipotent adult germline stem cells reveal similar transcriptomes including pluripotency-related genes.
Specimen part
View SamplesToxoplasma gondii is a ubiquitous apicomplexan parasite of mammals and birds and an important pathogen of humans. IFN-g is the major mediator of host resistance against T. gondii but intriguingly, parasite-infected host cells including macrophages are severely impaired to respond to IFN-g due to defective transcriptional activation of target genes. Here, we tested the possibility that the impaired responsiveness of T. gondii-infected macrophages to IFN-g can be restored by inhibiting histone deacetylases (HDACs) using the class I-specific inhibitor MS-275. Treatment of RAW264.7 cells with MS-275 indeed increased MHC class II surface expression in infected and non-infected cells and largely abolished the inhibition of IFN-g-regulated MHC class II expression exerted by T. gondii. Genome-wide transcriptome profiling revealed that MS-275 increased mean mRNA levels of IFN-g-regulated genes particularly in non-infected macrophages. Transcript levels of 33% of IFN-g secondary response genes but only those of a few primary response genes were also increased by MS-275 in T. gondii-infected cells. Importantly, the unresponsiveness of parasite-infected cells to IFN-g was however not abolished by MS-275. Furthermore, MS-275 also up-regulated several anti-inflammatory cytokines or signaling molecules in T. gondii-infected macrophages. It additionally regulated expression of more than 2500 genes in non-infected macrophages expression of which was surprisingly counteracted by prior infection with T. gondii. FACS analysis and immunofluorescence microscopy revealed that MS-275 did not considerably diminish the number of parasite-positive cells or the intracellular replication in macrophages stimulated or not with IFN-g. Thus, a supportive therapy using MS-275 appears inappropriate for treatment of toxoplasmosis. Overall design: High throughput RNA profiles from IFN-g-activated monocytic cells infected with Toxoplasma gondii and treated with MS-275 and control cells were generated by Illumina sequencing. Five experimental conditions with 2 biological replicates each were analysed.
Histone deacetylase inhibitor MS-275 augments expression of a subset of IFN-γ-regulated genes in Toxoplasma gondii-infected macrophages but does not improve parasite control.
Subject
View SamplesComparative analyses of Mex67 and Npl3 binding to mRNA at normal growth condition (25째C) and upon shift to heat stress (30 min, 42째C). Overall design: Examination of two biological RNA Co-IP replicates of Mex67, Npl3 and no tag control at 25째C and upon shift to 30 min at 42째C (Heat stress) and subsequent Illumina RNA deep-sequencing
mRNA quality control is bypassed for immediate export of stress-responsive transcripts.
Cell line, Subject
View SamplesThe aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor that is regulated by environmental toxicants that function as AHR agonists such as 2,3,7,8 tetrachlorodibenzo-p-dioxin (TCDD). L-Type Amino Acid Transporter 1 (LAT1) is a leucine uptake transporter that is overexpressed in cancer. The regulation of LAT1 by AHR in MCF-7 and MDA-MB-231 breast cancer cells (BCCs) was investigated in this report. Ingenuity pathway analysis (IPA) revealed a significant association between TCDD-regulated genes (TRGs) and molecular transport. Overlapping the TCDD-RNA-Seq dataset in this report with a published TCDD-ChIP-seq dataset identified that LAT1 was a direct TCDD/AHR gene target. Short interfering RNA (siRNA)-directed knockdown of AHR confirmed that TCDD-stimulated increases in LAT1 mRNA and protein required AHR. TCDD-stimulated increases in LAT1 mRNA was also inhibited by the AHR antagonist CH-223191. Upregulation of LAT1 by TCDD coincided with increases in leucine uptake by MCF-7 cells in response to TCDD. Chromatin immunoprecipitation-quantitative PCR (ChIP-qPCR) assays revealed increases in AHR, AHR nuclear translocator (ARNT) and p300 binding and histone H3 acetylation at an AHR binding site in the LAT1 gene in response to TCDD. In MDA-MB-231 cells, which exhibit high levels of endogenous AHR activity, the levels of endogenous LAT1 mRNA and protein were reduced in response to knockdown of AHR with AHR-siRNA. The regulation of LAT1 by AHR stimulated MDA-MB-231 proliferation. Collectively, these findings have provided a deeper mechanistic understanding of extrinsic and intrinsic regulation of LAT1 by AHR. Overall design: Expression profiling of four replicates of MCF-7 cells treated with 10nM TCDD were compared to expression profiles of four control replicates of MCF-7 cells treated with DMSO by RNA-Seq
Aryl hydrocarbon receptor (AHR) regulation of L-Type Amino Acid Transporter 1 (LAT-1) expression in MCF-7 and MDA-MB-231 breast cancer cells.
Treatment, Subject
View SamplesTo identify the gene expression profile of enteric glia and assess the transcriptional similarity between enteric and extraenteric glia, we performed RNA sequencing analysis on PLP1-expressing cells in the mouse intestine. This analysis shows that enteric glia are transcriptionally unique and distinct from other cell types in the nervous system. Enteric glia express many genes characteristic of the myelinating glia, Schwann cells and oli- godendrocytes, although there is no evidence of myelination in the murine ENS. Overall design: Total RNA expression profiles of PLP1 expressing enteric glial cells (GFP+) and non-glial cells (GFP-negative) were obtained from the ileum and colon of juvenile PLP1-eGFP transgenic mice.
Enteric glia express proteolipid protein 1 and are a transcriptionally unique population of glia in the mammalian nervous system.
Specimen part, Cell line, Subject
View SamplesWe performed gene expression profiling of total RNA from brain samples derived from BSE-infected versus non-infected cynomolgus macaques (Macaca fascicularis).
Gene expression profiling of brains from bovine spongiform encephalopathy (BSE)-infected cynomolgus macaques.
Sex, Age, Specimen part
View SamplesSeveral studies have shown that bone mineral density (BMD), a clinically measurable predictor of osteoporotic fracture, is the sum of genetic and environmental influences. In addition, serum IGF-1 levels have been correlated to both BMD and fracture risk. We previously identified a Quantitative Trait Locus (QTL) for Bone Mineral Density (BMD) on mouse Chromosome (Chr) 6 that overlaps a QTL for serum IGF-1. The B6.C3H-6T (6T) congenic mouse is homozygous for C57BL/6J (B6) alleles across the genome except for a 30 cM region on Chr 6 that is homozygous for C3H/HeJ (C3H) alleles. This mouse was created to study biology behind both the BMD and the serum IGF-1 QTLs and to identify the gene(s) underlying these QTLs. Female 6T mice have lower BMD and lower serum IGF-1 levels at all ages measured. As the liver is the major source of serum IGF-1, we examined differential expression in the livers of fasted female B6 and 6T mice by microarray.
A chromosomal inversion within a quantitative trait locus has a major effect on adipogenesis and osteoblastogenesis.
No sample metadata fields
View SamplesMost human tumors have abnormal numbers of chromosomes, a condition known as aneuploidy. The mitotic checkpoint is an important mechanism that prevents aneuploidy through restraining the activity of the anaphase-promoting complex (APC). USP44 was identified as a key regulator of APC activation that maintains the association of MAD2 with the APC co-activator Cdc20. However, the physiological importance of USP44 and its impact on cancer biology are unknown. Here, we show that USP44 is required to prevent tumors in mice and is frequently down-regulated in human lung cancer. USP44 inhibits chromosome segregation errors independently of its role in the mitotic checkpoint by regulating proper centrosome separation, positioning, and mitotic spindle geometry, functions that require direct binding to the centriole protein, centrin. These data reveal a new role for the ubiquitin system in mitotic spindle regulation and underscore the importance of USP44 in the pathogenesis of human cancer.
USP44 regulates centrosome positioning to prevent aneuploidy and suppress tumorigenesis.
Sex, Disease, Disease stage
View SamplesWe report the role of LSM1-7 complex in the Arabidopsis tolerance to abiotic stresses. LSM1-7 controls gene expression reprogramming at the post-transcriptional level by promoting the decapping of mRNA. This function is selectively achieve over selected stress-induced transcripts depending on stress nature. Overall design: Comparison of transcriptomes from Col-0 and lsm1a lsm1b plants exposed to low temperatures, drought or high salt conditions
The LSM1-7 Complex Differentially Regulates Arabidopsis Tolerance to Abiotic Stress Conditions by Promoting Selective mRNA Decapping.
Specimen part, Subject
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