Analysis of human peripheral blood 48 hours after irradiation ex vivo with graded doses of gamma rays. Results have been used in building and testing classifiers to predict exposure dose for use in radiological triage and also provide insight into immune cell responses. Results were compared with those from earlier times and from patients exposed in vivo. Peripheral blood from 5 healthy donors was exposed ex vivo to 0. 0.5 2 5 or 8 Gy gamma-rays and gene expression was analyzed up to 48 hours after exposure.

Analysis of human peripheral blood 48 hours after irradiation ex vivo with graded doses of gamma rays. Results have been used in building and testing classifiers to predict exposure dose for use in radiological triage and also provide insight into immune cell responses. Results were compared with those from earlier times and from patients exposed in vivo. Peripheral blood from 5 healthy donors was exposed ex vivo to 0. 0.5 2 5 or 8 Gy gamma-rays and gene expression was analyzed up to 48 hours after exposure.

This is a genome-wide approach to identifying genes persistently induced in the mouse mammary gland by acute whole body low dose ionizing radiation (10cGy) 1 and 4 weeks after exposure. Gene expression that is modified under these parameters were compared between Tgfb1 wild type and heterozygote littermates in order to determine which genes induced or repressed by radiation were mediated via Tgfb1 status. Differential gene expression was analyzed in Tgfb1 heterozygote and wild type littermate 4th mammary glands after whole body exposure to an acute dose of 10cGy ionizing radiation. Estrus cycle was normalized in all mice two days prior to irradiation by injection with an estrogen and progesterone mixture. It is widely believed that the carcinogenic action of ionizing radiation is due to targeted DNA damage and resulting mutations but there is also substantial evidence that non-targeted radiation effects alter epithelial phenotype and the stromal microenvironment. Activation of transforming growth factor beta 1 (TGFbeta) is a non-targeted radiation effect that mediates cell fate decisions following DNA damage and regulates microenvironment composition; it could either suppress or promote cancer. Gene expression profiling shown herein demonstrates that low dose radiation (10 cGy) elicits persistent changes in Tgfb1 wild type and heterozygote murine mammary gland that are highly modulated by TGFbeta. We asked if such non-targeted radiation effects contribute to carcinogenesis by using a novel radiation chimera model. Unirradiated Trp53 null mammary epithelium was transplanted to the mammary stroma of mice previously exposed to a single low (10 -100 cGy) radiation dose. By 300 days 100% of transplants in irradiated hosts at either 10 or 100 cGy had developed Trp53 null breast carcinomas compared to 54% in unirradiated hosts. Tumor growth rate was also increased by high but not low dose host irradiation. In contrast irradiation of Tgfb1 heterozygote mice prior to transplantation failed to decrease tumor latency or increase growth rate at any dose. Host irradiation significantly reduced the latency of invasive ductal carcinoma compared to spindle cell carcinoma as well as those tumors negative for smooth muscle actin in wild type but not Tgfb1 heterozygote mice. However irradiation of either host genotype significantly increased the frequency of estrogen receptor negative tumors. These data demonstrate two concepts critical to understanding radiation risks. First non-targeted radiation effects can significantly promote the frequency and alter the features of epithelial cancer. Second radiation-induced TGFbeta activity is a key mechanism of tumor promotion. Keywords: Differential gene expression after low dose irradiation Two genotypes: TGBbeta1 heterozygote and wildtype mouse mammary glands. Two time points post-10cGy-irradiation per genotype (1 week 4 weeks); control time point was 1 week post-sham-irradiation. Two or three replicates per time point.

One of the most likely risks astronauts on long duration space missions face is exposure to ionizing radiation associated with highly energetic and charged heavy (HZE) particles. Since access to medical expertise on such a mission is limited at best early diagnosis and mitigation of such exposure is critical. In order to accurately determine the dosage within 1 hour post-exposure dose-dependent biomarkers are needed. Therefore we performed a dose-course transcriptional analysis for radiation exposure at 0 0.3 1.5 and 3.0 Gy with corresponding time point at 1 hour (hr) post-exposure using Affymetrix GeneChip Human Gene 1.0 ST v1 Array chips. The analysis of our data suggests a set of sensitive genetic biomarkers specific to each radiation level as well as generic radiation response biomarkers. Upregulated biomarkers can then be used within lab-on-a-chip (LOC) systems to detect exposure to ionizing radiation. A total of sixteen human samples representing radiation exposure at levels 0 Gy 0.3 Gy 1.5 Gy and 3.0 Gy at time point 1 hour (hr) post-exposure were constructed. Blood samples were extracted from four human volunteers and were irradiated. Leukocytes were extracted and gene expression was measured. Samples for all four volunteers were measured at 1 hr for all four dose levels resulting in four replicates at each dose level. Thus a total of 4 samples at each of the four radiation levels were sampled yielding the total of 16 samples.

One of the most likely risks astronauts on long duration space missions face is exposure to ionizing radiation associated with highly energetic and charged heavy (HZE) particles. Since access to medical expertise on such a mission is limited at best early diagnosis and mitigation of such exposure is critical. In order to accurately determine the dosage within 1 hour post-exposure dose-dependent biomarkers are needed. Therefore we performed a dose-course transcriptional analysis for radiation exposure at 0 0.3 1.5 and 3.0 Gy with corresponding time point at 1 hour (hr) post-exposure using Affymetrix GeneChip Human Gene 1.0 ST v1 Array chips. The analysis of our data suggests a set of sensitive genetic biomarkers specific to each radiation level as well as generic radiation response biomarkers. Upregulated biomarkers can then be used within lab-on-a-chip (LOC) systems to detect exposure to ionizing radiation. A total of sixteen human samples representing radiation exposure at levels 0 Gy 0.3 Gy 1.5 Gy and 3.0 Gy at time point 1 hour (hr) post-exposure were constructed. Blood samples were extracted from four human volunteers and were irradiated. Leukocytes were extracted and gene expression was measured. Samples for all four volunteers were measured at 1 hr for all four dose levels resulting in four replicates at each dose level. Thus a total of 4 samples at each of the four radiation levels were sampled yielding the total of 16 samples.

Here we present a whole-genome survey of the murine transcriptomic response to physiologically-relevant radiation doses 2 and 8 Gy. There are 18 distinct biological samples here. Mice were exposed to ionizing radiation (Cesium-138 source) and whole blood was collected by cardiac puncture 6 hours post treatment. Doses were 0 (7 samples) 2 (5 samples) and 8 (6 samples) gy.

Background: The radiation bystander response is an important component of the overall response of cells to radiation and critical to understanding health risks of radiation exposure to humans. The mechanism of radiation response includes inter-cellular signaling and intra-cellular communication by which the bystander signal is propagated. Methods: We measured the bystander response to 1Gy a-particle radiation in Mrad9-/- mouse stem cells and H1299shRAD9 cells using chromosomal aberration and micronucleus formation as DNA damage endpoints. In the H1299 model we used whole genome microarray analyses to profile the transcriptome of irradiated and bystander cells. Results: We investigated the role of RAD9 in the bystander response and showed that depletion or mutation of RAD9 had an effect of increasing chromosomal structural damage as well as micronucleus formation in bystander cells. The enhancement of the damage effect correlated strongly with a transcriptomic response in critical pathways. RAD9 depletion affected many pathways in the cell including the UV-MAPK pathway involving p38MAPK members STAT1 and PARP1 at the mRNA levels. There was an overall reduction of RNA biogenesis of gene members of this pathway suggesting that perhaps these signaling pathways do not function optimally after RAD9 depletion. Using network analysis we found there may be differential activation of transcriptional regulators between the irradiated and bystander cells involving the SP1 and NUPR1 transcription factors. Network analysis also suggested that HIF1a (Hypoxia induced factor 1a) activation could be a negative predictor of the bystander effect and perhaps that local hypoxic stress observed by cells that are directly exposed to radiation may predict whether or not they will elicit a bystander response. Gene expression in H1299 cells was measured at 4 hours after exposure to 1 Gy a-particles. There were two groups based on RAD9 status RAD9 normal and RAD9 depleted by siRNA. In each of these groups sham irradiated direct irradiated cells for positive bystanders positive bystanders direct irradiated cells for negative bystanders and negative bystanders; were identified based on micronucleus responses. Five biological replicates were analyzed for each experimental group.

To investigate DNA methylation patterns in rat mammary carcinomas induced by ionizing radiation. DNA methylation patterns were analyzed in radiation-induced rat mammary carcinomas and normal mammary gland tissues using CpG island microarray.

Cesium-137 is a radionuclide of concern in fallout from reactor accidents or nuclear detonations. When ingested or inhaled it can expose the entire body for an extended period of time potentially contributing to serious health consequences ranging from acute radiation syndrome to increased cancer risks. In order to identify changes in gene expression that may be informative for detecting such exposure and to begin examining the molecular responses involved we have profiled global gene expression in mice injected with 137CsCl. We extracted RNA from the blood of control or 137CsCl-injected mice at 2 3 5 20 or 30 days after exposure. Gene expression was measured using Agilent Whole Mouse Genome Microarrays and the data was analyzed using BRB-ArrayTools. Three-month old male C57Bl/6 mice were injected intraperitoneally with 8.0 xc2 xb1 0.3 MBq 137CsCl solution in a volume of 50 xce xbcL or left as controls. Groups of treated and control mice were sacrificed at intervals during the first 2-30 days after exposure and total blood was collected using cardiac puncture. RNA was extracted from the blood globin-transcript reduced and subjected to whole genome expression microarray analysis.

To further development of our gene expression approach to biodosimetry we have employed whole genome microarray expression profiling as a discovery platform to identify genes with the potential to distinguish radiation dose across an exposure range relevant for medical decision-making in a radiological emergency. Human peripheral blood from healthy donors was irradiated ex vivo and a 74-gene consensus signature was identified that distinguished between four radiation doses (0.5 2 5 and 8 Gy) and control samples. The same set of genes separated samples by exposure level at both six and 24 hours after treatment with overlap evident only at the highest two doses (5 and 8 Gy). Expression of five genes (CDKN1A FDXR SESN1 BBC3 and PHPT1) from this signature was quantified in the same RNA samples by real-time PCR confirming low variability between donors as well as the predicted radiation response pattern. Experiment Overall Design: Radiation induced gene expression in human blood was measured at 6 and 24 hours after exposure to doses of 0 0.5 2 5 and 8 Gy g-rays. Five independent experiments were performed at each time (6 or 24 hours) using different donors for each experiment