The aberrant landscape of DNA methylation and gene expression during arsenic-induced cell transformation
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ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Francisco Barajas-Olmos
PROVIDER: E-MTAB-7973 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
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Project description:We describe the alterations in DNA methylation around the promoter region and the impact on gene expression in HaCaT cells during the transformation process caused by chronic exposure to arsenic. Nucleic acids were extracted at the beginning of treatment and at weeks 0, 5, 15, and 25. Cell cultures with the same passage (week 25) and no arsenic treatment served as controls.
2019-11-02 | E-MTAB-7972 | biostudies-arrayexpress
Project description:The purpose of this study is to search for aberrant genes in HaCaT keratinocytes after chronic exposure to arsenic trioxide. The objective of the investigation was to discover the mechanism of arsenic carcinogenicity in human epidermal keratinocytes. We hypothesize that a combined strategy of DNA microarray, qRT-PCR and gene function annotation will identify aberrantly expressed genes in HaCaT keratinocyte cell line after chronic treatment with arsenic trioxide. HaCaT cells were chronically exposed to 0.5M-BM-5g/mL arsenic trioxide (As2O3) up to 22 passages and RNA was extracted. Microarray data analysis identified 14 up-regulated genes and 21 down-regulated genes in response to arsenic trioxide Two experimental groups: 1. The treatment group was sub-cultured up to passage 22 to establish a chronic exposure state. 2. The passage control group was also sub-cultured up to 22 passages but with no exposure to arsenic trioxide. 4 technical replicates with 3 replicates making a total of 8X3 =24 samples HaCat Cell untreated (passage control): 1. H1_H001, H1_H002, H1_H003 2. H2_ H004, H2_H005, H2_H006 3. H3_ H007, H3_H008, H3_H009 4. H4_ H010, H4_H011, H4_H012 HaCat Cell treated with 0.5M-BM-5g/ml of arsenic trioxide: 5. A1_H013, A1_H014, A1_H015 6. A2_H016, A2_H017, A2_H018 7. A3_H019, A3_H020, A3_H021 8. A4_H022, A4_H023, A4_H024 Cell Type: Human Skin Keratinocyte: 1.5 M-CM-^W105 HaCaT cells were cultured in 7.5 ml of complete DMEM containing 10% Fetal Bovine Serum (FBS) and 1% penicillin, streptomycin in T-25 culture plate. Cells were incubated in a humidified atmosphere with 5% CO2 at 37 M-BM-:C. The treatment groups were exposed to 0.5M-BM-5g/mL As2O3 (equivalent to LC 0.5), and passaged at 90% confluent. Total RNA was extracted from 4 technical replicates of unexposed HaCaT cells and HaCaT cells chronically exposed to arsenic trioxide up to passage 22 using RNA STAT-60 (TEL-TEST, INC, Friendswood, TX, USA).
2012-04-11 | E-GEOD-37192 | 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: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. Experiment Overall Design: 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.
2008-06-16 | E-GEOD-9630 | biostudies-arrayexpress
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: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:Arsenic is a carcinogen that is known to induce cell transformation and tumor formation. Although studies have been performed to examine the modulation of signaling molecules caused by arsenic exposure, the molecular mechanisms by which arsenic causes cancer are still unclear. We hypothesized that arsenic alters gene expression leading to carcinogenesis in the lung. In this study, we examined global gene expression in response to 0.75 M-BM-5M arsenic treatment for 1-7 days in a rat lung epithelial cell line (L2) using an in-house 10k rat DNA microarray. One hundred thirty one genes were identified using the one-class statistical analysis of microarray (SAM) test. Of them, 33 genes had a fold change of M-bM-^IM-% 2 at least between two time points. These genes were then clustered into 5 groups using K-means cluster analysis based on their expression patterns. Seven selected genes, all associated with cancer, were confirmed by real-time PCR. These genes have functions directly or indirectly related to metabolism, glycolysis, cell proliferation and differentiation, and regulation of transcription, all of which may be involved in neoplastic transformation of cells. Our findings provide important insight for the future studies of arsenic-mediated lung cancer. Keywords: Lung, aresenic, L2, micorarray L2 cells were exposed with 0.75 uM of arsenite for 0, 1, 3, 5, and 7 days (C, D1, D3, D5 and D7). The samples were arranged for hybridization using a loop design. For each paired sample, dye flip and three biological replications were performed for each sample.
2011-12-23 | E-GEOD-9790 | biostudies-arrayexpress
Project description:Chronic exposure to arsenic is associated with dermatological and non-dermatological disorders. Consumption of arsenic contaminated drinking water results in accumulation of arsenic in liver, spleen, kidneys, lungs and gastrointestinal tract. Although, arsenic is cleared from these sites, a substantial amount of residual arsenic is left in keratin-rich tissues such as skin. Epidemiological studies on arsenic suggest the association of skin cancer upon arsenic exposure, however, the exact mechanism of arsenic induced carcinogenesis is not completely understood. We have developed a cell line-based model to understand the molecular mechanisms involved in arsenic mediated toxicity and carcinogenicity. Human skin keratinocyte cell line, HaCaT was exposed to 100nM sodium arsenite for six months. We observed an increase in the basal ROS levels in arsenic exposed cells along with the increase in anti-apoptotic proteins. SILAC-based quantitative proteomics approach resulted in the identification and quantitation of 2,181 proteins of which 39 proteins were found to be overexpressed (≥2-fold) and 56 downregulated (≤2-fold) upon chronic arsenic exposure. Our study provides comprehensive insights into the molecular basis of chronic arsenic exposure on skin.
2017-01-02 | PXD001645 | Pride
Project description:To analyse the transcriptional response of Rhodococcus aetherivornas BCP1 to arsenic, RNA was extracted from BCP1 cultures exposed to arsenite [As(III)] 5 mM and arsenate [As(V)] 30 mM for 18 hours in the presence of glucose as only carbon and energy source. Control cultures were carried out without adding any arsenic oxyanions. Illumina Truseq stranded mRNA libraries were constructed after rRNA depletion via Illumina Ribozero and sequenced on Illumina HiSeq 1500 system 2 x 70nt PE rapid mode.
2021-12-31 | E-MTAB-10692 | biostudies-arrayexpress
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 which could lead to altered gene expression 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.
2014-09-17 | E-GEOD-44169 | biostudies-arrayexpress