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PROVIDER: PRJNA188945 | ENA |
REPOSITORIES: ENA
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Project description:Sodium arsenite induced DNA methylation changes in A549 human epithelial lung carcinoma cells
| PRJNA188955 | ENA
Project description:Sodium arsenite induced gene expression changes in A549 human epithelial lung carcinoma cells
| PRJNA188954 | ENA
Project description:Arsenic (As) exposure is a significant worldwide environmental health concern. Low dose, chronic arsenic exposure has been associated with higher risk of skin, lung, and bladder cancer, as well as cardiovascular disease and diabetes. While arsenic-induced biological changes play a role in disease pathology, little is known about the dynamic cellular changes due to arsenic exposure and withdrawal. In these studies, we seek to understand the molecular mechanisms behind the biological changes induced by chronic low doses of arsenic exposure. We used a comprehensive approach involving chromatin structural studies and mRNA microarray analyses to determine how chromatin structure and gene expression patterns change in response to chronic low dose arsenic exposure and its subsequent withdrawal. Our results show that cells exposed to low doses of sodium arsenite have distinct temporal and coordinated chromatin, gene expression and miRNA changes that are consistent with differentiation and activation of multiple biochemical pathways. Most of these temporal patterns in gene expression are reversed when arsenic was withdrawn. However, some of the gene expression patterns remained altered, plausibly as a result of an adaptive response by these cells. Additionally, these gene expression patterns correlated with changes in chromatin structure, further solidifying the role of chromatin structure in gene regulatory changes due to arsenite exposure. Lastly, we show that arsenite exposure influences gene regulation both at the transcription initiation as well as at the splicing level. Thus our results suggest that general patterns of alternative splicing, as well as expression of particular gene regulators, can be indicative of arsenite-induced cell transformation. A total of eight (8) samples with two biological replicates under four separate conditions: wild-type treated with deionized H2O for 36 days (NT); chronic low-dose arsenic exposure of 1 uM of sodium arsenite (iAs-T) for 36 days; chronic arsenic exposure of 1 uM of sodium arsenite for 26 days followed by removal of sodium arsenite for 10 days, measured at day 36 (iAs-Rev); and chronic arsenic exposure of 1 uM of sodium arsenite for 26 days, followed by removal of sodium arsenite exposure for 10 days, followed by 1 uM of chronic sodium arsenite exposure for 10 days (measured at day 46) (iAs-Rev-T).
2015-05-05 | E-GEOD-60760 | biostudies-arrayexpress
Project description:Epithelial-mesenchymal transition (EMT) is an important mechanism in carcinogenesis. To determine the mechanisms that are involved in the regulation of EMT is crucial to develop new biomarkers and therapeutic targets towards cancers. In this study, when TGFÃ1 and TNFa were used to induce EMT in human lung carcinoma A549 cells, we were surprised to find an increase in an epithelial cell tight junction marker, Claudin 1. We further identified that it was the TNFa and not the TGFÃ1 that induced the fibroblast-like morphology changes. TNFa also caused the increase in Claudin-1 gene expression and protein levels in Triton X-100 soluble cytoplasm fraction. Down-regulation of Claudin-1, using small interfering RNA (siRNA), inhibited 75% of TNFa-induced gene expression changes. Claudin-1 siRNA effectively blocked TNFa-induced molecular functional networks related to inflammation and cell movement. Wound-healing assay showed that Claudin-1 siRNA was able to significantly reduce TNF-enhanced cell migration. Furthermore, over expression of Claudin 1 with a Claudin 1-pcDNA3.1/V5-His vector enhanced cell migration. In conclusion, these observations indicate that Claudin 1 acts as a critical signal mediator in TNFa-induced gene expression and cell migration in human lung cancer cells. Further analyses of these cellular processes may be helpful in developing novel therapeutic strategies. 4 groups (with or without TNFα, control or Claudin 1 siRNA) of human lung adenocarcinoma A549 cells with 3 replicates per group.
2012-06-12 | E-GEOD-32254 | biostudies-arrayexpress
Project description:Arsenic is a potent environmental toxin and a cause of numerous health problems. Most studies have assumed that arsenic-induced changes in mRNA levels result from effects on gene transcription. The influence of arsenic on post-transcriptional regulation, another important locus of gene expression control, has remained largely unexplored. To evaluate the prevalence of changes in mRNA stability in response to arsenic in human fibroblasts, we used microarray analyses to determine changes in steady state mRNA levels, and their decay rates, following 24 hour exposure to non-cytotoxic concentrations of sodium arsenite (1 µM). We conclude that arsenite modification of mRNA stability is relatively uncommon, but in some instances can result in significant changes in gene expression. Human BJ diploid foreskin fibroblasts were used in the study. The decay rates of transcripts were determined using actinomycin D to stop transcription after sodium arsenite or water treatment for 24 h. Actinomycin D was added into the culture medium at a final concentration of 5 µg/ml, and treated cells were then harvested at 0, 1, 2, 3 and 4 h for RNA extraction.
2015-04-15 | E-GEOD-57051 | biostudies-arrayexpress
Project description:Exposure to high levels of arsenic in drinking water is associated with several types of cancers including lung, bladder and skin, as well as vascular disease and diabetes. Drinking water standards are based primarily on epidemiology and extrapolation from higher dose experiments, rather than measurements of phenotypic changes associated with chronic exposure to levels of arsenic similar to the current standard of 10ppb, and little is known about the difference between arsenic in food as opposed to arsenic in water. Measurement of phenotypic changes at low doses may be confounded by the effect of laboratory diet, in part because of trace amounts of arsenic in standard laboratory chows, but also because of broad metabolic changes in response to the chow itself. Finally, this series contrasts 8hr, 1mg/kg injected arsenic with the various chronic exposures, and also contrasts the acute effects of arsenic, dexamethasone or their combination. Male C57BL/6 mice were fed on two commercially available laboratory diets (LRD-5001 and AIN-76A) were chronically exposed, through drinking water or food, to environmentally relevant concentrations of sodium arsenite, or acutely exposed to dexamethasone. Experiment Overall Design: Male C57BL/6 mice, fed on two commercially available laboratory diets (LRD-5001 and AIN-76A), were chronically exposed through drinking water or food, to environmentally relevant concentrations of sodium arsenite. Another group animals, fed on the AIN 76A diet, was IP injected with dexamethasone (1 mg/kg), sodium arsenite (1mg/kg), both dexamethosone and arsenite, or saline alone.
2008-10-21 | E-GEOD-11056 | biostudies-arrayexpress
Project description:The aim of the experiment is to identify kinetic changes in host gene expression upon infection of A549 lung epithelial carcinoma cells with human corona virus HCoV-229E as compared to unifected cells. Negativ controls include infections with heat-inactivated virus. Positive controls include treatment of cells with human IL-1alpha (10ng/ml) for 1h. All experiments have been performed at 33°C which is required for sufficient viral entry/replication.
2017-03-15 | GSE89159 | GEO
Project description:Arsenic is methylated during its metabolism, thereby depleting the intracellular methyl donor S-adenosyl-methionine, which may lead to disturbances in DNA methylation patterns Cells were exposed to sodium arsenite (NaAsO2, Sigma) at concentrations of 0.08 M-BM-5M, 0.4 M-BM-5M and 2 M-BM-5M for 1, 2 and 8 weeks. A549 arsenic dose time response study.
2014-09-17 | E-GEOD-44173 | biostudies-arrayexpress
Project description:Arsenic is a potent environmental toxin and a cause of numerous health problems. Most studies have assumed that arsenic-induced changes in mRNA levels result from effects on gene transcription. The influence of arsenic on post-transcriptional regulation, another important locus of gene expression control, has remained largely unexplored. To evaluate the prevalence of changes in mRNA stability in response to arsenic in human fibroblasts, we used microarray analyses to determine changes in steady state mRNA levels, and their decay rates, following 24 hour exposure to non-cytotoxic concentrations of sodium arsenite (1 µM). We conclude that arsenite modification of mRNA stability is relatively uncommon, but in some instances can result in significant changes in gene expression.
2015-04-15 | GSE57051 | GEO