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.

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

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

The radiation bystander effect is an important component of the overall biological response of tissues and organisms to ionizing radiation. Little is known about the contribution of genome level changes in neighboring bystander cells to tissue and organ stress after irradiation. The timing of these changes is critical in the physiological context and these questions can only be answered by studying signaling and global transcriptomics in a chronological way. Here we present a strategy to identify different biologically important signaling modules that act in concert in the radiation and bystander responses. We used time series gene expression analysis of normal human fibroblast cells measured at 0.5 hour 1 hour 2 hours 4 hours 6 hours and 24 hours after exposure to radiation coupled with a novel clustering method targeted to short time series Feature Based Partitioning around medoids Algorithm (FBPA) to look for genes that were potentially co-regulated. This method uses biologically meaningful features of the expression profile and dimension augmentation to address the analysis of sparse data sets such as ours. We applied FBPA and Short Time series Expression Miner (STEM) to the same datasets and present the results of our comparisons using computational metrics as well as biological enrichment. Enrichment showed that gene expression in irradiated cells fell into broad categories of signal transduction cell cycle/cell death and inflammation/immunity; but only FBPA clustered functions well. In bystander cells the gene expression response was also broadly categorized into functions associated with cell communication and motility signal transduction and inflammation; but neither STEM nor FBPA separated biological functions as well as in irradiated samples. Network analysis revealed that p53 and NF-kappaB were central players in gene expression in both irradiated and bystander gene clusters. Analysis of individual clusters also suggested new regulators of gene expression in the radiation and bystander response that may act at the epigenetic level such as histone deacetylases (HDAC1 and HDAC2) and methylases (KDM5B) that can act as strong transcription repressors. Based on these results we propose a novel time series clustering method FBPA as a powerful approach that can be applied to sparse data sets (including genomic profiling data) where the choice of features selected for clustering and stringent statistical outcome analysis can augment our knowledge of the underlying cellular mechanisms in biological processes. There are 72 total samples 4 corresponding biological replicates of IMR90 cells that were not irradiated (control=C) irradiated (alpha=A) and bystander (B) cells were harvested at 0.5 hour 1 hour 2 hours 4 hours 6 hours and 24 hours after treatment

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.

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.

Accumulating data support the concept that ionizing radiation therapy (RT) has the potential to convert the tumor into an in situ individualized vaccine; however this potential is rarely realized by RT alone. Transforming growth factor xce xb2 (TGF xce xb2) is an immunosuppressive cytokine that is activated by RT and inhibits the antigen-presenting function of dendritic cells and the differentiation of effector CD8+ T cells. Here we tested the hypothesis that TGF xce xb2 hinders the ability of RT to promote anti-tumor immunity. Development of tumor-specific immunity was examined in a pre-clinical model of metastatic breast cancer. Mice bearing established 4T1 mouse mammary carcinoma treated with pan-isoform specific TGF xce xb2 neutralizing antibody 1D11 showed significantly improved control of the irradiated tumor and non-irradiated metastases but no effect in the absence of RT. Notably whole tumor transcriptional analysis demonstrated the selective upregulation of genes associated with immune-mediated rejection only in tumors of mice treated with RT+TGF xce xb2 blockade. Mice treated with RT+TGF xce xb2 blockade exhibited cross-priming of CD8+ T cells producing IFN xce xb3 in response to three tumor-specific antigens in tumor-draining lymph nodes which was not evident for single modality treatment. Analysis of the immune infiltrate in mouse tumors showed a significant increase in CD4+ and CD8+ T cells only in mice treated with the combination of RT+TGF xce xb2 blockade. Depletion of CD4+ or CD8+ T cells abrogated the therapeutic benefit of RT+TGF xce xb2 blockade. These data identify TGF xce xb2 as a master inhibitor of the ability of RT to generate an in situ tumor vaccine which supports testing inhibition of TGF xce xb2 during radiotherapy to promote therapeutically effective anti-tumor immunity. We used genome-wide microarray to depict main biological processes responsibles for the therapeutic benefit of the combination ofTGF-beta blockade and local radiotherapy. To gain a more comprehensice protrait of the effects of RT and TGFbeta blockade on gene expressionin tumors we collected 4T1 tumors 4 days after completion of RT. Three tumors from each group were then subjected to RNA extraction and hybridization on affymetrix array.

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.

Accumulating data support the concept that ionizing radiation therapy (RT) has the potential to convert the tumor into an in situ individualized vaccine; however this potential is rarely realized by RT alone. Transforming growth factor xce xb2 (TGF xce xb2) is an immunosuppressive cytokine that is activated by RT and inhibits the antigen-presenting function of dendritic cells and the differentiation of effector CD8+ T cells. Here we tested the hypothesis that TGF xce xb2 hinders the ability of RT to promote anti-tumor immunity. Development of tumor-specific immunity was examined in a pre-clinical model of metastatic breast cancer. Mice bearing established 4T1 mouse mammary carcinoma treated with pan-isoform specific TGF xce xb2 neutralizing antibody 1D11 showed significantly improved control of the irradiated tumor and non-irradiated metastases but no effect in the absence of RT. Notably whole tumor transcriptional analysis demonstrated the selective upregulation of genes associated with immune-mediated rejection only in tumors of mice treated with RT+TGF xce xb2 blockade. Mice treated with RT+TGF xce xb2 blockade exhibited cross-priming of CD8+ T cells producing IFN xce xb3 in response to three tumor-specific antigens in tumor-draining lymph nodes which was not evident for single modality treatment. Analysis of the immune infiltrate in mouse tumors showed a significant increase in CD4+ and CD8+ T cells only in mice treated with the combination of RT+TGF xce xb2 blockade. Depletion of CD4+ or CD8+ T cells abrogated the therapeutic benefit of RT+TGF xce xb2 blockade. These data identify TGF xce xb2 as a master inhibitor of the ability of RT to generate an in situ tumor vaccine which supports testing inhibition of TGF xce xb2 during radiotherapy to promote therapeutically effective anti-tumor immunity. We used genome-wide microarray to depict main biological processes responsibles for the therapeutic benefit of the combination ofTGF-beta blockade and local radiotherapy. To gain a more comprehensice protrait of the effects of RT and TGFbeta blockade on gene expressionin tumors we collected 4T1 tumors 4 days after completion of RT. Three tumors from each group were then subjected to RNA extraction and hybridization on affymetrix array.