Primary human hepatocytes (PHH) are a main instrument in drug metabolism research and in the prediction of drug-induced phase I/II enzyme induction in humans. The HepG2 liver-derived cell line is commonly used as a surrogate for human hepatocytes, but their use in ADME and toxicity studies can be limited because of lowered basal levels of metabolizing enzymes. Despite their widespread use, the transcriptome of HepG2 cells compared to PHH is not well characterized. In this study, microarray analysis was conducted to ascertain the differences and similarities in mRNA expression between HepG2 cells and human hepatocytes before and after exposure to a panel of fluoroquinolone compounds. Comparison of the nave HepG2 cell and PHH transcriptomes revealed a substantial number of basal gene expression differences. When HepG2 cells were dosed with a series of fluoroquinolones, trovafloxacin, which has been associated with human idiosyncratic hepatotoxicity, induced substantially more gene expression changes than the other quinolones, similar to previous observations with PHH. While TVX-treatment resulted in many gene expression differences between HepG2 cells and PHH, there were also a number of TVX-induced commonalities, including genes involved in RNA processing and mitochondrial function. Taken together, these results provide insight for interpretation of results from drug metabolism and toxicity studies conducted with HepG2 cells in lieu of PHH, and could provide further insight into the mechanistic evaluation of TVX-induced hepatotoxicity.
Trovafloxacin-induced gene expression changes in liver-derived in vitro systems: comparison of primary human hepatocytes to HepG2 cells.
Sex, Specimen part
View SamplesIndividuals expressing alpha-1-antitrypsin mutant Z protein accumulate misfolded, mutant protein in the liver and are at risk for liver diseases including cirrhosis and hepatocellular carcinoma. Transgenic PiZ mice, a model for this liver disease, display similar pathologies to humans, including inflammation, increases in proliferation, autophagy and apoptosis, accumulation of globules and develop fibrosis and hepatocellular carcinoma with age. Microarrays were used to compare the gene expressions of PiZ mice to wild-type mice in order to identify the pathways that are altered in this disorder.
Oxidative stress contributes to liver damage in a murine model of alpha-1-antitrypsin deficiency.
Sex, Specimen part
View SamplesSplenic Transitional Type-1 B-cells from CBA wild-type mice, X-linked immunodeficiency mice and Bruton's tyrosine kinase knock-out mice. Two replicates where run on Affymetrix 420 2.0 arrays for CBA wild-type, Xid samples and the Btk KO samples.
Distinct gene expression signature in Btk-defective T1 B-cells.
Specimen part
View SamplesBruton's tyrosine kinase (Btk) is important for B lymphocyte development. To identify genes that are differentially expressed in primary B cells lacking functional Btk, splenocytes from X-linked immunodeficiency (Xid), Btk knockout (KO) and immunocompetent CBA mice, were used in microarrays containing more than 12,000 genes and expressed sequence tags (ESTs). We found 4515 transcripts expressed in duplicate experiments in all three strains. Out of these, 38 were differentially expressed genes (21 up-regulated >2 fold and 17 down-regulated <-2 fold) between CBA and Btk defective mice. Ten out of these genes were selected and quantitative Real-Time PCR was conducted for validation and further investigation. Real-Time experiments correlated nicely with the microarray data.
Gene expression profile of B cells from Xid mice and Btk knockout mice.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Transcriptional signatures of Itk-deficient CD3+, CD4+ and CD8+ T-cells.
No sample metadata fields
View SamplesGlobal gene expression profiling of the avian B-lymphoma DT40 cell line was used as a model to differentiate among Btk KO and Btk KO cells reconstituted with human Btk. Differences in the gene expression pattern showed statistically significant changes between parental DT40 and all the Btk KO cell populations irrespective of whether they are reconstituted or not. These results imply that in the process of generating a knockout cell line, subclones are selected, which have multiple changes in their gene expression pattern (p<0.01).
Expression profiling of chicken DT40 lymphoma cells indicates clonal selection of knockout and gene reconstituted cells.
No sample metadata fields
View SamplesThe Tec-family kinase Itk plays an important role during T-cell activation and function, and controls also conventional versus innate-like T-cell development. We have characterized the transcriptome of Itk-deficient CD3+ T-cells, including CD4+ and CD8+ subsets, using Affymetrix microarrays. The largest difference between Itk-/- and Wt CD3+ T-cells was found in unstimulated cells, e.g. for killer cell lectin-like receptors. Compared to anti-CD3-stimulation, anti-CD3/CD28 significantly decreased the number of transcripts suggesting that the CD28 co-stimulatory pathway is mainly independent of Itk. The signatures of CD4+ and CD8+ T-cell subsets identified a greater differential expression than in total CD3+ cells. Cyclosporin (CsA)-treatment had a stronger effect on transcriptional regulation than Itk-deficiency, suggesting that only a fraction of TCR-mediated calcineurin/NFAT-activation is dependent on Itk. Bioinformatic analysis of NFAT-sites of the group of transcripts similarly regulated by Itk-deficiency and CsA-treatment, followed by chromatin-immunoprecipitation, revealed NFATc1-binding to the Bub1, IL7R, Ctla2a, Ctla2b, and Schlafen1 genes. Finally, to identify transcripts that are regulated by Tec-family kinases in general, we compared the expression profile of Itk-deficient T-cells with that of Btk-deficient B-cells and a common set of transcripts was found. Taken together, our study provides a general overview about the global transcriptional changes in the absence of Itk.
Transcriptional signatures of Itk-deficient CD3+, CD4+ and CD8+ T-cells.
No sample metadata fields
View SamplesThe Tec-family kinase Itk plays an important role during T-cell activation and function, and controls also conventional versus innate-like T-cell development. We have characterized the transcriptome of Itk-deficient CD3+ T-cells, including CD4+ and CD8+ subsets, using Affymetrix microarrays. The largest difference between Itk-/- and Wt CD3+ T-cells was found in unstimulated cells, e.g. for killer cell lectin-like receptors. Compared to anti-CD3-stimulation, anti-CD3/CD28 significantly decreased the number of transcripts suggesting that the CD28 co-stimulatory pathway is mainly independent of Itk. The signatures of CD4+ and CD8+ T-cell subsets identified a greater differential expression than in total CD3+ cells. Cyclosporin (CsA)-treatment had a stronger effect on transcriptional regulation than Itk-deficiency, suggesting that only a fraction of TCR-mediated calcineurin/NFAT-activation is dependent on Itk. Bioinformatic analysis of NFAT-sites of the group of transcripts similarly regulated by Itk-deficiency and CsA-treatment, followed by chromatin-immunoprecipitation, revealed NFATc1-binding to the Bub1, IL7R, Ctla2a, Ctla2b, and Schlafen1 genes. Finally, to identify transcripts that are regulated by Tec-family kinases in general, we compared the expression profile of Itk-deficient T-cells with that of Btk-deficient B-cells and a common set of transcripts was found. Taken together, our study provides a general overview about the global transcriptional changes in the absence of Itk.
Transcriptional signatures of Itk-deficient CD3+, CD4+ and CD8+ T-cells.
No sample metadata fields
View SamplesThe mRNA processing body is a cellular structure that regulates the stability of cytoplasmic mRNA. MARF1/LMKB is an RNA-binding protein that is associated with maintenance of mRNA homeostasis and genomic stability. To investigate the function of LMKB in a human B lymphocyte cell line, BJAB cells were treated with either control lentivirus or a lentivirus containing LMKB siRNA.
LMKB/MARF1 localizes to mRNA processing bodies, interacts with Ge-1, and regulates IFI44L gene expression.
Specimen part, Cell line
View SamplesBreast cancer stem cells are considered estrogen receptor negative and estrogen insensitive. However, estrogens potentiate growth of the vast majority of breast tumors. In this study, we characterize the expression of estrogen receptors in breast cancer stem cells.
mTOR inhibitors counteract tamoxifen-induced activation of breast cancer stem cells.
Specimen part, Treatment
View Samples