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:The ability to detect trace amounts of ionizing radiation is a paramount concern for chemical, biological, radiological, nuclear, and explosives (CBRNE) operations and observation of clandestine activities in the event of source relocation and contamination. Microbes respond to environmental stress such as fluctuations in pH and temperature, nutrient limited conditions, and oxidative stress with morphological and behavioral changes, and induced responses are known to persist after the stressor is removed. Innate responses to other external stressors like exposure to low-dose ionizing radiation could be measured and characterized by changes in gene expression and resulting transcriptional changes could by engineered into biosensors to monitor and discern the presence and type of radiation, respectively, in the environment. The current understanding of the biological and transcriptional responses of bacteria to various doses of ionizing radiation is minimal. The work in this study expands upon the findings in our previous study of the response of a model bacterium to low doses of ionizing radiation soil bacterium, Pseudomonas putida KT2440. Following exposure to an approximate absorbed dose rate of 9 mGy d-1 of a 239Pu, 3H, or 55Fe source, RNA-seq analysis revealed key changes in gene expression of P. putida of genes encoding membrane components, central carbon metabolism, DNA repair pathways, and motility. Several genes were differentially expressed genes in P. putida after exposure to multiple radionuclide sources. Moreover, other genes were uniquely differentially expressed by a single radionuclide source. These findings expand upon the limited understanding of the biological response to low doses of ionizing radiation and provide fundamental characterization required to develop discriminatory RNA-based biosensors.
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.
