Project description:The goal of this study was to compare the radiation-induced gene translation profiles generated from human tumor cell lines that are treated with radiation. Keywords: stimulus or stress design
Project description:The goal of this study was to compare the radiation-induced gene translation profiles generated from human tumor cell lines that are treated with radiation. Keywords: stimulus or stress design A panel of cell lines included 5 gliomas, 4 pancreatic carcinomas, 3 breast carcinomas and 2 non-small cell lung carcinomas. In addition, radiation-induced gene translation profiles were generated for 4 normal human cell lines: a skin fibroblast (BJ), 2 lung fibroblasts (MRC5, MRC9) and mammary epithelial (MEC). Specifically, cell lines were exposed to 2 Gy or sham irradiated, polysome-bound RNA was isolated 6h later and subjected to microarray analyses. Each cell line was evaluated in biological replicates.
Project description:Recent studies have further heightened awareness of the risk of radiation-induced cancer after diagnostic radiology imaging, in particular, brain cancer following childhood CT scans. One feature of Ptch1+/- mice is that they are sensitive to radiation-induced medulloblastomas (an embryonic cerebellar tumor) during a narrow time window centered on the days around birth. The dynamics of how dose-protraction interacts with such narrow windows of sensitivity in individual tissues is still unknown. Using medulloblastomas from irradiated Ptch1+/- mice on a hybrid C3H × C57BL/6 F1 background, we have previously shown that the alleles retained on chromosome 13 (which harbors the Ptch1 gene) reveal two major mechanisms of loss of the wildtype allele. The loss of parental alleles from the telomere extending up to or past the Ptch1 locus by recombination (spontaneous-type) accounts for almost all medulloblastomas in unirradiated mice, while tumors in irradiated mice often exhibited interstitial deletions which start downstream of the wildtype Ptch1 and extend up varying lengths towards the centromere (radiation-type). Here, Ptch1+/- mice were exposed to an acute dose of 0.1 or 0.5 Gy gamma rays in utero or postnatally, or the same radiation doses protracted over a 4-day period, and were monitored for medulloblastoma development. The results show dose-dependent and age-dependent induction of radiation-type tumors; that the size of the radiation-induced deletion differs with the dose-rate; and, that tumor latency may be related to the size of the deletion. The radiation signature allows for unique mechanistic insight into the action of radiation to induce DNA lesions with known causal relationship to a specific tumor type, particularly for doses and dose-rates more relevant to diagnostic radiology imaging and accidental exposure of populations to radiation.
Project description:Although ionizing radiation has been shown to influence gene transcription, little is known about the effects of radiation on gene translational efficiency. To obtain a genome-wide perspective of the effects of radiation on gene translation, microarray analysis was done on polysome-bound RNA isolated from irradiated human brain tumor cells; to allow for a comparison with the effects of radiation on transcription, microarray analysis was also done using total RNA. The number of genes whose translational activity was modified by radiation was f10-fold greater than those whose transcription was affected. The radiation-induced change in a gene’s translational activity was shown to involve the recruitment of existing mRNAs to and away from polysomes. Moreover, the change in a gene’s translational activity after irradiation correlated with changes in the level of its corresponding protein. These data suggest that radiation modifies gene expression primarily at the level of translation. In contrast to transcriptional changes, there was considerable overlap in the genes affected at the translational level among brain tumor cell lines and normal astrocytes. Thus, the radiation-induced translational control of a subset of mRNAs seems to be a fundamental component of cellular radioresponse. (Cancer Res 2006; 66(2): 1052-61) There are 32 samples in total in this study. Each sample has a technical duplicate (16samples x2). Comparison of radiation-induced gene expression profiles generated from microarray analysis of total and polysome-bound RNA isolated from three brain tumor cell lines U87, SF126, SF539 and normal astrocytes. Cells were irradiated at the dose of 7gy and collected 6 hours later for isolation of total cellar RNA or polysome-bound RNA. Gene expression was directly compared between irradiated and unirradiated control cells for total and polysome RNA. The array labeling is two-dye method. Labeling two dye samples are labeled using CY3 dye. All the human reference RNA from Stratagene are labeled using CY5 dye.
Project description:Although ionizing radiation has been shown to influence gene transcription, little is known about the effects of radiation on gene translational efficiency. To obtain a genome-wide perspective of the effects of radiation on gene translation, microarray analysis was done on polysome-bound RNA isolated from irradiated human brain tumor cells; to allow for a comparison with the effects of radiation on transcription, microarray analysis was also done using total RNA. The number of genes whose translational activity was modified by radiation was f10-fold greater than those whose transcription was affected. The radiation-induced change in a gene’s translational activity was shown to involve the recruitment of existing mRNAs to and away from polysomes. Moreover, the change in a gene’s translational activity after irradiation correlated with changes in the level of its corresponding protein. These data suggest that radiation modifies gene expression primarily at the level of translation. In contrast to transcriptional changes, there was considerable overlap in the genes affected at the translational level among brain tumor cell lines and normal astrocytes. Thus, the radiation-induced translational control of a subset of mRNAs seems to be a fundamental component of cellular radioresponse. (Cancer Res 2006; 66(2): 1052-61)
Project description:Radiation therapy is an effective cancer treatment although damage to healthy tissues is common. Here we establish sequencing-based, cell-type specific DNA methylation reference maps of human and mouse tissues to infer the origins of cell-free DNA fragments released from dying cells into the circulation. We find cell-type specific DNA blocks mostly hypomethylated and located within genes intrinsic to cellular identity. In a mouse model, thoracic radiation-induced tissue damages were reflected by dose-dependent increases in lung endothelial, cardiomyocyte and hepatocyte methylated DNA in serum. The analysis of serum samples from breast cancer patients undergoing radiation treatment revealed distinct tissue-specific epithelial and endothelial responses to radiation across multiple organs. Strikingly, patients treated for right-sided breast cancers also showed increased hepatocyte and liver endothelial DNA in the circulation indicating the impact on liver tissues. Thus, cell-free methylated DNA in serum can uncover cell-type specific effects of radiation on healthy tissues and inform treatment.
Project description:Radiation therapy is an effective cancer treatment although damage to healthy tissues is common. Here we establish sequencing-based, cell-type specific DNA methylation reference maps of human and mouse tissues to infer the origins of cell-free DNA fragments released from dying cells into the circulation. We find cell-type specific DNA blocks mostly hypomethylated and located within genes intrinsic to cellular identity. In a mouse model, thoracic radiation-induced tissue damages were reflected by dose-dependent increases in lung endothelial, cardiomyocyte and hepatocyte methylated DNA in serum. The analysis of serum samples from breast cancer patients undergoing radiation treatment revealed distinct tissue-specific epithelial and endothelial responses to radiation across multiple organs. Strikingly, patients treated for right-sided breast cancers also showed increased hepatocyte and liver endothelial DNA in the circulation indicating the impact on liver tissues. Thus, cell-free methylated DNA in serum can uncover cell-type specific effects of radiation on healthy tissues and inform treatment.
Project description:Radiation therapy is an effective cancer treatment although damage to healthy tissues is common. Here we establish sequencing-based, cell-type specific DNA methylation reference maps of human and mouse tissues to infer the origins of cell-free DNA fragments released from dying cells into the circulation. We find cell-type specific DNA blocks mostly hypomethylated and located within genes intrinsic to cellular identity. In a mouse model, thoracic radiation-induced tissue damages were reflected by dose-dependent increases in lung endothelial, cardiomyocyte and hepatocyte methylated DNA in serum. The analysis of serum samples from breast cancer patients undergoing radiation treatment revealed distinct tissue-specific epithelial and endothelial responses to radiation across multiple organs. Strikingly, patients treated for right-sided breast cancers also showed increased hepatocyte and liver endothelial DNA in the circulation indicating the impact on liver tissues. Thus, cell-free methylated DNA in serum can uncover cell-type specific effects of radiation on healthy tissues and inform treatment.
Project description:Radiation therapy is an effective cancer treatment although damage to healthy tissues is common. Here we establish sequencing-based, cell-type specific DNA methylation reference maps of human and mouse tissues to infer the origins of cell-free DNA fragments released from dying cells into the circulation. We find cell-type specific DNA blocks mostly hypomethylated and located within genes intrinsic to cellular identity. In a mouse model, thoracic radiation-induced tissue damages were reflected by dose-dependent increases in lung endothelial, cardiomyocyte and hepatocyte methylated DNA in serum. The analysis of serum samples from breast cancer patients undergoing radiation treatment revealed distinct tissue-specific epithelial and endothelial responses to radiation across multiple organs. Strikingly, patients treated for right-sided breast cancers also showed increased hepatocyte and liver endothelial DNA in the circulation indicating the impact on liver tissues. Thus, cell-free methylated DNA in serum can uncover cell-type specific effects of radiation on healthy tissues and inform treatment.
Project description:Radiation therapy is an effective cancer treatment although damage to healthy tissues is common. Here we establish sequencing-based, cell-type specific DNA methylation reference maps of human and mouse tissues to infer the origins of cell-free DNA fragments released from dying cells into the circulation. We find cell-type specific DNA blocks mostly hypomethylated and located within genes intrinsic to cellular identity. In a mouse model, thoracic radiation-induced tissue damages were reflected by dose-dependent increases in lung endothelial, cardiomyocyte and hepatocyte methylated DNA in serum. The analysis of serum samples from breast cancer patients undergoing radiation treatment revealed distinct tissue-specific epithelial and endothelial responses to radiation across multiple organs. Strikingly, patients treated for right-sided breast cancers also showed increased hepatocyte and liver endothelial DNA in the circulation indicating the impact on liver tissues. Thus, cell-free methylated DNA in serum can uncover cell-type specific effects of radiation on healthy tissues and inform treatment.