Project description:Exposure to high-dose radiation causes life-threatening serious intestinal damage. Histological analysis is the most accurate method for judging the extent of intestinal damage after death. However, it is difficult to predict the extent of intestinal damage to body samples. Here we focused on extracellular microRNAs (miRNAs) released from cells and investigated miRNA species that increased or decreased in serum and feces using a radiation-induced intestinal injury mouse model. A peak of small RNA of 25–200 nucleotides was detected in mouse serum and feces 72 h after radiation exposure, and miRNA presence in serum and feces was inferred. MiRNAs expressed in the small intestine and were increased by more than 2.0-fold in serum or feces following a 10 Gy radiation exposure were detected by microarray analysis and were 4 in serum and 19 in feces. In this study, miR-375-3p, detected in serum and feces, was identified as the strongest candidate for a high-dose radiation biomarker in serum and/or feces using a radiation-induced intestinal injury model.
Project description:Exposure to high-dose radiation causes life-threatening intestinal damage. Histopathology is the most accurate method of judging the extent of intestinal damage following death. However, it is difficult to predict the extent of intestinal damage. The present study investigated extracellular microRNAs (miRNAs or miRs) in serum and feces using a radiation-induced intestinal injury mouse model. A peak of 25-200 nucleotide small RNAs was detected in mouse serum and feces by bioanalyzer, indicating the presence of miRNAs. Microarray analysis detected four miRNAs expressed in the small intestine and increased by >2-fold in serum and 19 in feces following 10 Gy radiation exposure. Increased miR-375-3p in both serum and feces suggests leakage due to radiation-induced intestinal injury and may be a candidate for high-dose radiation biomarkers.
Project description:Previously, we used mouse and non-human primate models to show that serum miRNAs may predict the biological impact of lethal and sublethal radiation doses. We hypothesized that these results can be replicated in humans treated with total body irradiation (TBI), and that miRNAs may be used as clinically feasible biodosimeters. To test this hypothesis, serial serum samples were obtained from 25 patients who underwent allogeneic stem-cell transplantation and profiled for miRNA expression using next-generation sequencing. Differential expression results were largely consistent with previous studies and allowed us to select miRNAs, including miR-150-5p, miR-126-5p, miR-375, miR-215-5p, miR-144-5p, miR-122-5p, miR-320d and miR-10b-5p to build classifiers using qPCR-based quantification. We therefore conclude that serum miRNAs reflect radiation exposure and dose for humans undergoing TBI and may be used as functional biodosimeters for precise identification of people exposed to clinically significant radiation doses.
Project description:Biomarkers of tumour response to radiotherapy could help in optimising cancer treatment. In this study, we focus on identifying changes in extracellular miRNA as a biomarker of radiation-induced damage to human colorectal cancer cells. HCT116 cells were exposed to increasing doses of X-rays, and extracellular miRNAs were analysed by microarray. The results were correlated with frequencies of micronuclei. Fifty-nine miRNAs with positive correlation and four with negative correlation between dose (up to 6 Gy) and expression of extracellular miRNA were verified. In addition, for samples between 0 and 10 Gy, 12 miRNAs into those 59 miRNAs with positive correlation were verified. Of these, these miRNAs showed significantly positive correlation up to 10 Gy between micronucleus frequency and expression of extracellular miRNA. These results suggest that specific miRNAs could be cell damage markers and could serve as secreted radiotherapy response biomarkers for colorectal cancer; however, the results must be validated in serum samples collected from patients undergoing radiotherapy.
Project description:Dose dependent expression of extracellular microRNAs in HCT116 colorectal cancer cells exposed to high dose rate ionizing radiation
Project description:Expression profiles in mouse liver exposed to long-term gamma-irradiation were examined to assess in vivo effects of low dose-rate radiation. Three groups of male C57BL/6J mice were exposed to whole body irradiation at dose-rates of 17-20 mGy/day, 0.86-1.0 mGy/day or 0.042-0.050 mGy/day for 401-485 days (cumulative doses were approximately 8 Gy, 0.4 Gy or 0.02 Gy, respectively). Expression profiles were produced for RNA isolated from irradiated individual animals and for pooled RNA from sham-irradiated 3 animals for control. The expression levels of 6 irradiated animals for each dose were compared individually with those of 2 pooled controls (3 irradiated samples to one pooled control in first and second experiments).
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 (RT) induces pleiotropic effects on the tumor immune microenvironment, but how these changes are modulated by radiation dose-fractionation is not well understood. Our in vivo data murine data suggests that while changes evoked by RT in the tumor immune compartment are largely concordant between radiation regimens, several key immunological processes are differentially regulated by radiation dose-fractionation.