ABSTRACT: Genetic differences in transcript responses to low-dose ionizing radiation identify tissue functions associated with breast cancer susceptibility.
Project description:Skin is usually exposed during human exposures to ionizing radiation, however there are few experiments that evaluate the radiation responsiveness of the cells of the epidermis (keratinocytes) and those of the dermis (fibroblasts) in the same studies. We evaluated the transcriptional responses of quiesent primary keratinocytes and fibroblasts from the same individual and compared them with quiescent keratinocytes and fibroblasts that were immortalized by human telomerase (hTert). The primary transcriptional responses to 10-500 cGy ionizing radiation were p53-mediated responses; however, we did identify distinct responses between the keratinocytes and the fibroblasts. Keywords: keratinocytes and fibroblasts - dose response to ionizing radiation
Project description:Thyroid gland is among the most sensitive organs to ionizing radiation. Whether low-dose radiation-induced papillary thyroid cancer (PTC) differs from sporadic PTC is yet unknown. We used microarrays to identify gene signature of radiation-induced papillary thyroid carcinomas
Project description:Thyroid gland is among the most sensitive organs to ionizing radiation. Whether low-dose radiation-induced papillary thyroid cancer (PTC) differs from sporadic PTC is yet unknown. We used microarrays to identify gene signature of radiation-induced papillary thyroid carcinomas To identify molecular differences between radiation-induced (Exposed to Chernobyl Radiation, ECR) and sporadic PTC, we investigated 65 childhood/young adult PTC samples using DNA microarray (Affymetrix, Human Genome U133 2.0 Plus). The PTC samples were from patients born either before (33 ECR cases) or at least 9 months after (32 non-ECR cases) the Chernobyl catastrophe. Multofactoral analyses were performed in order to define some additional factors that could have impact on the gene expression profile. Morover the microarray data were validated with the QPCR reaction and exon arrays.
Project description:Investigation of ATM-dependent and dose-dependent, or -independent, responses were examined in human lymphoblast cells 6 hr following exposure to either 1 or 5 Gy ionizing radiation. Human lymphoblast cells from "apparently healthy" individuals and individuals with Ataxia telangiectasia were exposed to 1 Gy or 5 Gy ionizing radiation. Gene expression responses 6 hr following IR were examined. Untreated samples were hybridized together with their matched treated samples.
Project description:Characterization of biological and chemical responses to ionizing radiation by various organisms is essential for potential applications in bioremediation, alternative modes of detecting nuclear material, and national security. Escherichia coli DH10β is an optimal system to study the microbial response to low-dose ionizing radiation at the transcriptional level because it is a well-characterized model bacterium and its responses to other environmental stressors, including those to higher radiation doses, have been elucidated in prior studies. In this study, RNA sequencing with downstream transcriptomic analysis (RNA-seq) was employed to characterize the global transcriptional response of stationary-phase E. coli subjected to Pu-239, H-3 (tritium), and Fe-55, at an approximate absorbed dose rate of 10 mGy day-1 for 1 day and 15 days. Differential expression analysis identified significant changes in gene expression of E. coli for both short- and long-term exposures. Radionuclide source exposure induced differential expression in E. coli of genes involved in biosynthesis pathways of nuclear envelope components, amino acids, and siderophores, transport systems such as ABC transporters and type II secretion proteins, and initiation of stress response and regulatory systems of temperature stress, the RpoS regulon, and oxidative stress. These findings provide a basic understanding of the relationship between low-dose exposure and biological effect of a model bacterium that is critical for applications in alternative nuclear material detection and bioremediation. IMPORTANCE Escherichia coli strain DH10β, a well-characterized model bacterium, was subjected to short-term (1-day) and long-term (15-day) exposures to three different in situ radiation sources comprised of radionuclides relevant to nuclear activities to induce a measurable and identifiable genetic response. We found E. coli had both common and unique responses to the three exposures studied, suggesting both dose rate- and radionuclide-specific effects. This study is the first to provide insights into the transcriptional response of a microorganism in short- and long-term exposure to continuous low-dose ionizing radiation with multiple in situ radionuclide sources and the first to examine microbial transcriptional response in stationary phase. Moreover, this work provides a basis for the development of biosensors and informing more robust dose-response relationships to support ecological risk assessment.
Project description:Low-dose radiation refers to exposure to ionizing radiation at levels that are generally considered safe and not expected to cause immediate health effects. However, the effects of low-dose radiation are still not fully understood and research in this area is ongoing. In this study, we investigated changes in gene expression in diabetic human aortic endothelial cells (T2D-HAECs) derived from type 2 diabetes patients. To this end, we used RNA-seq to profile the transcriptomes of cells exposed to varying doses of low-dose radiation (0.1Gy, 0.5Gy, and 2.0Gy) and compared them to a control group with no radiation exposure. Differentially expressed genes and enriched pathways were identified using the DESeq2 and gene set enrichment analysis (GSEA) methods, respectively. The data generated in this study are publicly available through the gene expression omnibus (GEO) database. This study provides a valuable resource for studying the effects of low-dose radiation on T2D-HAECs and can contribute to a better understanding of the potential human health risks associated with low-dose radiation exposure.