Project description:Low and high doses of X-rays are used in medicine as diagnostic and therapeutic tools, respectively. While response to high doses of radiation is well known, contradictions exist about effects of low-dose irradiation. Therefore, improving the knowledge on the consequences of low-dose irradiation could help to address this controversy. Moreover, describing new insights into high-dose irradiation would improve new cancer therapies combining radiation and gene therapy. As long non-coding RNAs (lncRNAs) seems to be engaged to almost all biological functions, including response to DNA damage, we aimed to describe the participation of lncRNAs in the response to different doses of X-ray exposure. We observed that, in human breast epithelial cells, different sets of coding and non-coding transcripts are differentially regulated at moderate and high doses compared to low doses. The validation of expression of five lncRNAs only regulated at high and moderate X-ray doses supports our results. Altogether, we could conclude that response to moderate and high dose irradiation versus response to low-doses also differs in terms of lncRNA expression. Therefore, further studies on the participation of lncRNAs in this response to radiation would help to address controversies regarding low-dose irradiation response and to improve therapies using high-dose irradiation.
Project description:MicroRNA (miRNA) is a type of non-coding RNA that regulates the expression of its target genes by interacting with the complementary sequence of the target mRNA molecules. Recent evidence has shown that genotoxic stress induces miRNA expression, but the target genes involved and role in cellular responses remain unclear. We examined the role of miRNA in the cellular response to X-ray irradiation by studying the expression profiles of radio-responsive miRNAs and their target genes in cultured human cell lines. We found that expression of miR-574-3p was induced in the lung cancer cell line A549 by X-ray irradiation. Overexpression of miR-574-3p caused delayed growth in A549 cells. A predicted target site was detected in the 3'-untranslated region of the enhancer of the rudimentary homolog (ERH) gene, and transfected cells showed an interaction between the luciferase reporter containing the target sequences and miR-574-3p. Overexpression of miR-574-3p suppressed ERH protein production and delayed cell growth. This delay was confirmed by knockdown of ERH expression. Our study suggests that miR-574-3p may contribute to the regulation of the cell cycle in response to X-ray irradiation via suppression of ERH protein production. miRNA expression were measured at 1 and 3 h after exposure to doses of 0, 2 or 20 Gy. Microarray experiments were performed with duplicate for each experiment.
Project description:This dataset is composed by the transcriptomic, proteomic and phosphoproteomic profile of primary human fibroblasts exposed to two different doses of radiation: an acute X-ray radiation dose, and an accumulative X-ray radiation dose. These data were employed to apply and evaluate different computational approaches to model and infer cellular signaling processes through the combination of prior knowledge and omic data. We employed RNA-Seq and Mass Spectrometry (MS) to generate the transcriptomic and proteomic data from the RNA and protein samples, respectively.
Project description:Early exposure to xenoestrogens may predispose to breat cancer risk later in adult life. The long-lived, self-regenerating epithelial progenitor cells are more susceptible to these exposure injuries and transmit the injured memory throught epigenetic mechanisms to their differentiated progeny. We have established a breast progenitor model for epigenetic study and our previous work demonstrated that DNA methylation profiling of epithelial progeny derived from progenitors exposed to estradiol detected hypermethylated loci in 0.5% of protein-coding genes. In this study, we extended this exposure study to non-coding microRNA genes.
Project description:Early exposure to xenoestrogens may predispose to breat cancer risk later in adult life. The long-lived, self-regenerating epithelial progenitor cells are more susceptible to these exposure injuries and transmit the injured memory throught epigenetic mechanisms to their differentiated progeny. We have established a breast progenitor model for epigenetic study and our previous work demonstrated that DNA methylation profiling of epithelial progeny derived from progenitors exposed to estradiol detected hypermethylated loci in 0.5% of protein-coding genes. In this study, we extended this exposure study to non-coding microRNA genes. Three mammosphere-derived epithelial cell (MDEC) sample sets from three independent patients. Each sample set includes one DES-preexposed and one DMSO-preexposed MDEC.
Project description:Exposure to radiation provokes cellular responses controlled in part by gene expression networks. MicroRNAs (miRNAs) are small non-coding RNAs which mostly regulate gene expression by degrading the messages or inhibiting translation. Here, we investigated changes in miRNA expression patterns after low (0.1 Gy) and high (2.0 Gy) doses of X-ray in human fibroblasts. At early (0.5 h) and late (6 and 24 h) time points, irradiation caused qualitative and quantitative differences in the down-regulation of miRNA levels, including miR-92b, 137, 660, and 656. A transient up-regulation of miRNAs was observed after 2 h post-irradiation following high doses of radiation, including miR-558 and 662. MicroRNA levels were inversely correlated with targets from mRNA and proteomic profiling after 2.0 Gy of radiation. MicroRNAs miR-579, 608, 548-3p, and 585 are noted for targeting genes involved in radioresponsive mechanisms, such as cell cycle checkpoint and apoptosis. We suggest here a model in which miRNAs may act as "hub" regulators of specific cellular responses, immediately down-regulated so as to stimulate DNA repair mechanisms, followed by up-regulation involved in suppressing apoptosis for cell survival. Taken together, miRNAs may mediate signaling pathways in sequential fashion in response to radiation, and may serve as biodosimetric markers of radiation exposure. The gene expression patterns in human fibroblasts after 2.0 Gy of low-LET radiation was determined at 2 and 24 hrs post-irradiation time in technical triplicates. Control non-irradiated samples were also prepared in triplicates.
Project description:Exposure to radiation provokes cellular responses controlled in part by gene expression networks. MicroRNAs (miRNAs) are small non-coding RNAs which mostly regulate gene expression by degrading the messages or inhibiting translation. Here, we investigated changes in miRNA expression patterns after low (0.1 Gy) and high (2.0 Gy) doses of X-ray in human fibroblasts. At early (0.5 h) and late (6 and 24 h) time points, irradiation caused qualitative and quantitative differences in the down-regulation of miRNA levels, including miR-92b, 137, 660, and 656. A transient up-regulation of miRNAs was observed after 2 h post-irradiation following high doses of radiation, including miR-558 and 662. MicroRNA levels were inversely correlated with targets from mRNA and proteomic profiling after 2.0 Gy of radiation. MicroRNAs miR-579, 608, 548-3p, and 585 are noted for targeting genes involved in radioresponsive mechanisms, such as cell cycle checkpoint and apoptosis. We suggest here a model in which miRNAs may act as "hub" regulators of specific cellular responses, immediately down-regulated so as to stimulate DNA repair mechanisms, followed by up-regulation involved in suppressing apoptosis for cell survival. Taken together, miRNAs may mediate signaling pathways in sequential fashion in response to radiation, and may serve as biodosimetric markers of radiation exposure.
Project description:Gene expression microarrays were used to compare gene alterations induced by exposure to equitoxic doses of crocidolite asbestos and cristobalite silica in an isolate of normal human bronchial epithelial cells. Primary human bronchial epithelial cells (NHBE) were exposed to crocidolite asbestos, cristobalite silica, and saline as control for 24 hours. Total RNA was extracted from cell cultures, 3 separate cultures were used for each condition. The isolated RNA was used to analyze mRNA expression via Affymetix GeneChip Human U133A 2.0 arrays.
Project description:Human deep space and planetary travel is limited by uncertainties regarding the health risks associated with exposure to galactic cosmic radiation (GCR), and in particular the high linear energy transfer (LET), heavy ion component. Here we assessed the impact of two high-LET ions 56Fe and 28Si, and low-LET X rays on genome-wide methylation patterns in human bronchial epithelial cells. We found that all three radiation types induced rapid and stable changes in DNA methylation but at distinct subsets of CpG sites affecting different chromatin compartments. The 56Fe ions induced mostly hypermethylation, and primarily affected sites in open chromatin regions including enhancers, promoters and edges (“shores”) of CpG islands. The 28Si ion-exposure had mixed effects, inducing both hyper and hypomethylation and affecting sites in more repressed heterochromatic environments, whereas X rays induced mostly hypomethylation, primarily at sites in gene bodies and intergenic regions. Significantly, the methylation status of 56Fe ion irradiation sensitive sites, but not those affected by X ray or 28Si ions, could discriminate tumor from normal tissue for human lung adenocarcinomas and squamous cell carcinomas. Thus, high LET radiation exposure leaves a lasting imprint on the epigenome, and affects sites relevant to human lung cancer. The 56Fe ion signature may prove useful in monitoring the cumulative biological impact and associated cancer risks encountered by astronauts in deep space. Genome wide DNA methylation profiling of normal human bronchial epithelial cells irradiated with varying doses of 28Si-ion radiation ( 300 MeV/u at 0, 0.3, 1.0 Gy) , 56Fe-ion radiation (600 MeV/u at 0, 0.1, 0.3, 1.0 Gy) or X rays (320 kV at 0, 1.0 Gy). Triplicate control and irradiated samples were incubated and sampled at 4 timepoints between 2 and 62 days. The Illumina Infinium 450k Human DNA methylation Beadchip was used to obtain DNA methylation profiles across >485,000 CpGs from collected samples. Samples include: 56Fe ions, 4 doses x 4 time points x 3 replicates (4 removed in QC) = 44 samples; 28Si ions = 3 doses x 4 time points x 3 replicates = 36 samples; X ray, 2 doses x 4 time points x 3 replicates (2 removed in QC)= 22 samples.
Project description:Ionizing Radition is known to cause cell damage. Human peripheral blood mononuclear cells have long been used to study radiation induced gene expression profiling. Whithin this study we evaluated gene and microRNA expression alterations of human PBMC irradiated with 60 Gy g-ray. Cells were cultured for 2, 4 and 20h after irradiation before RNA was isolated and Agilent Human microRNA Microarrays was performed. Radiation induced gene expression in human peripheral blood mononuclear cells were measured at 2, 4 and 20 hours after exposure to doses of 60 Gy g-rays. Non radiated cell of each donor and time point were used as contol cells. Four independent experiments were performed at each time (2, 4, or 20 hours and 0 h - only 1 sample per donor) using 4 different donors.