Project description:This SuperSeries is composed of the following subset Series:; GSE14383: Effects of chronic exposure of human bronchial epithelial cells to low doses of cigarette smoke condensate; GSE14385: Response of bronchial epithelial cells to low doses of cigarette smoke condensate and subsequent demethylation agent Experiment Overall Design: Refer to individual Series
Project description:The study seeks to identify the epigenetic changes caused by exposure of to cigarette smoke condensate. To this goal human bronchial epithelial cells, BEAS-2B, were treated with 5-aza-2’deoxycitidine and trychostatin A (5AzaC/TSA) subsequent to a chronic exposure (1 month) to cigarette smoke condensate (CSC). As negative control served BEAS-2B cells that were untreated or treated with CSC/DMSO for one month without the subsequent application of 5Aza/TSA. Keywords: stress response
Project description:The study seeks to identify the epigenetic changes caused by exposure of to cigarette smoke condensate. To this goal human bronchial epithelial cells, BEAS-2B, were treated with 5-aza-2âdeoxycitidine and trychostatin A (5AzaC/TSA) subsequent to a chronic exposure (1 month) to cigarette smoke condensate (CSC). As negative control served BEAS-2B cells that were untreated or treated with CSC/DMSO for one month without the subsequent application of 5Aza/TSA. Experiment Overall Design: BEAS-2B Cells were treated for one month with CSC, DMSO, and left untreated. Subsequently half of the samples were treated with the demethylation agent. So that there were six different conditions with three biological replicates each. One sample had to be excluded because of low quality.
Project description:Repeated exposure and switching study of cigarette smoke and next generation tobacco product using 3D human bronchial epithelial cells
Project description:Exposure to genotoxic stresses such as cosmic radiation and second-hand tobacco smoke may increase the risk of breast cancer formation. Towards an understanding of how exposure to these genotoxic agents affect breast cancer biogenesis, we have shown that treating non-tumorigenic immortalized breast MCF 10A cells with low doses (0.1 Gray) of radiation as well as cigarette smoke condensate can generate a neoplastic breast cancer phenotype. The transformed phenotype promoted increased mammosphere numbers, altered cell cycle phases, and increased invasion and motility. In addition, exclusion of Hoechst 33342 dye, a surrogate marker for increased ABC transporters, was observed, which indicates a possible increase in drug resistance. Furthermore, differential gene expression profiles were generated from the individual and combination treatment. Overall, the results indicate that when normal breast cells are exposed to low dose radiation in combination with cigarette smoke condensate a phenotype is generated that exhibits traits indicative of neoplastic transformation. Taken together, these results provide a new insight into a possible etiology for breast cancer formation in individuals exposed to cosmic radiation and second-hand smoke. To study the effects of low dose ionizing radiation and tobacco smoke on breast cells, MCF 10A cells were treated either with radiation (Rad - 0.1 Gray) or cigarette smoke condensate (Csc - 10 microgram/ml of medium) or a combination of Rad + Csc). Following treatments, the cells were incubated for 72 hr, RNA extracted and analyzed for differential gene expression pattern.
Project description:Exposure to cigarette smoke is a leading cause of lung diseases including chronic obstructive pulmonary disease and cancer. Cigarette smoke is a complex aerosol containing over 6000 chemicals, and thus it is difficult to determine individual contributions to overall toxicity, and the molecular mechanisms by which smoke constituents exert their effects. We selected three well-known harmful and potentially harmful constituents (HPHCs) in tobacco smoke: acrolein, formaldehyde and catechol and established a High Content Screening (HCS) method using normal human bronchial epithelial cells, which are the first bronchial cells in contact with cigarette smoke. The impact of each HPHC was investigated using 13 multi-parametric indicators of cellular toxicity and complemented with a microarray-based whole transcriptome analysis followed by a computational approach leveraging mechanistic network models to identify and quantify perturbed molecular pathways. HPHCs were evaluated over a wide range of concentrations and at different exposure time points (4 h, 8 h, and 24 h). By High Content Screening, the toxic effects of the three HPHCs could only be observed at the highest doses. Whole genome transcriptomics unraveled toxicity mechanisms at lower doses and earlier time points. The most prevalent toxicity mechanisms observed were: DNA damage/growth arrest, oxidative stress, mitochondrial stress and apoptosis/necrosis. In summary, combination of multiple toxicological endpoints with a systems-based impact assessment allows for a more robust scientific basis for the toxicological assessment of HPHCs that allows insight into time- and dose-dependent molecular perturbations of specific biological pathways. This approach allowed us to establish an in vitro Systems Toxicology platform that can be applied to a broader selection of HPHCs and their mixtures and can serve more generally as the basis for testing the impact of other environmental toxicants on normal bronchial epithelial cells.