Primary term human trophoblasts exposed to ionizing irradiation
ABSTRACT: Primary term human trophoblasts were derived from placentas after a healthy pregnancy, and exposed to ionizing irradiation (vs sham) in vitro Primary human trophoblasts were irradiated 24 h after initial plating, defined as time zero. Cells were irradiated at 10 Gy using a Clinac 600C (Varian Medical Systems, Palo Alto, CA) with a 6 MV photon beam and a dose rate of 250 cGy/min. The flasks containing the cells were placed on 1.5 cm of bolus (a tissue equivalent material) since the maximum irradiation depth was 1.5 cm, which corresponded to the plated cell layer. Cells were analyzed 4, 8, and 24 h after irradiation or sham.
Project description:The bystander effect from ionizing radiation consists of cellular responses generated from non-irradiated cells to the irradiation of their neighbors. The bystander effect is predominant at low doses and can lead to DNA damage and genomic instability in the affected cells. This non-targeted effect of radiation has received attention due to its potential implications for cancer therapy and radiation protection. Although studied extensively, a complete understanding of its molecular mechanism is the subject of ongoing research. While many studies have targeted specific factors which are suggested to be involved in the bystander effect, few have looked at whole genome gene expression in bystander cells. Furthermore, even fewer studies have looked at the expression in normal human cell lines. In this study, we have monitored transcriptional responses to γ-radiation in irradiated and bystander normal fibroblasts simultaneously using a genome-wide microarray approach. Bystander fibroblasts incubated in medium from irradiated cells, showed transient enrichment (less than 1.5 fold) in ribosome and oxidative phosphorylation pathways, and neurodegenerative disease pathways associated with mitochondrial dysfunctions. Bystander fibroblasts did not, however, display increases in oxidative stress, a phenomenon often linked with the radiation induced bystander effect. Total RNA was isolated from normal human fibroblasts irradiated with 2.0 Gy and fibroblasts incubated with medium from sham irradiated and irradiated cells 2 h after irradiation. RNA was isolated 4, 8 and 26 h after irradiation and there are 4 replicates for each sample for a total of 36 samples.
Project description:The bystander effect from ionizing radiation consists of cellular responses generated from unirradiated cells to the irradiation of their neighbors. The bystander effect can lead to DNA damage and genomic instability in the affected cells. This non-targeted effect of radiation has received attention due to its potential implications for cancer therapy and radiation protection. Although studied extensively, a complete understanding of its molecular mechanism is the subject of ongoing research. While many studies have targeted specific factors which are suggested to be involved in the bystander effect, few have looked at whole genome gene expression in bystander cells. Furthermore, even fewer studies have looked at the expression in noncancerous human cell lines. In this study we have used a genome-wide microarray approach to investigate transcriptional responses in irradiated and bystander immortalized human fibroblasts following 0.1 Gy α-particle irradiation. Total RNA was isolated from F11hTERT fibroblasts irradiated with 0.1 Gy α-particles and bystander fibroblasts receiving medium from control (sham irradiated) and irradiated cells (0.1 Gy). RNA was isolated 4, 8 and 26 h after irradiation.
Project description:To check gene expression signatures for LGR5hi and LGR5lo ISCs in response to gamma-irradiation, we performed whole genome microarray on LGR5hi and LGR5lo ISCs purified from irradiated mice or non-irradiated mice Radiation induced gene expression in LGR5hi and LGR5lo ISCs of LGR5-GFPki mice was measured at 3 hours after exposure to 12Gy γ-irradiation or non-irradiation.
Project description:The objective of the experiment was to compare changes in the transcriptome induced by direct X-irradiation of cells and by factors released by irradiated cells into the culture medium (irradiation conditioned medium, ICM), using the K562 human erythroleukemic cell line. Two culture flasks with K562 cells (5 x 105 cells/ml) were irradiated with X-rays at the dose of 4 Gy and in both the culture medium was changed immediately after irradiation, after 1 hour of recovery in fresh medium in standard growth conditions medium containing factors released by irradiated cells was collected from one flask, filtered from cell debris and untreated control K 562 cells were grown in this medium in standard conditions for 36h. The irradiated cells of the second flask were incubated for 36 hours in parallel and RNA was isolated from both irradiated and Irradiation Conditioned Medium-exposed samples. The transcript levels were measured in these RNA samples using Affymetrix HGU 133A microarrays and compared to the levels in RNA from control cells grown for 36h or control cells collected after 1h after change of medium. Experiments were repeated twice.
Project description:microRNA regulates cellular responses to ionizing radiation (IR) through the translational control of target genes. We analyzed time-series changes in microRNA expressions upon γ-irradiation in H1299 lung cancer cell lines using microarray. Significantly changed microRNAs were selected based on ANOVA analysis, target genes of which were enriched to MAPK signaling pathway. Concurrent analysis of mRNA and microRNA uncovered that the expression of miR-26b and its target ATF2 mRNA were inversely correlated in γ-irradiated H1299 cells. The overexpression of miR-26b induced the suppression of ATF2 in γ-irradiated cells. When we inhibit the MAPK signaling pathway using SP600125, JNK inhibitor, the expression of miR-26b was induced even in γ-irradiated H1299 cells. From these results, we concluded that the expression of miR-26b was coordinated regulated by MAPK signaling pathway upon ionizing radiation, and MAPK signaling pathway was regulated by miR-26b in turn. We analyzed the time-series miRNA profiles of radioresistant H1299 cells in response to 2 Gy of ionizing radiation (IR) by performing quadratic regression (QR) analysis to identify genes associated with radioresistance
Project description:We developed a mouse model that captures radiation effects on host biology by transplanting unirradiated Trp53 null mammary tissue to sham or irradiated hosts. Gene expression profiles of tumors that arose in irradiated mice are distinct from those that arose in naïve hosts. Host irradiation induces a metaprofile consisting of gene modules representing stem cells, cell motility, macrophages and autophagy. Human orthologs of the host irradiation metaprofile discriminated between radiation-preceded and sporadic human thyroid cancers. An irradiated host centroid was strongly associated with estrogen receptor negative breast cancer. When applied to sporadic human breast cancers, the irradiated host metaprofile strongly associated with basal-like and claudin-low breast cancer intrinsic subtypes. Comparing host irradiation in the context of TGFβ levels showed that inflammation was robustly associated with claudin-low tumors. The association of the irradiated host metaprofiles with estrogen receptor negative status and claudin-low subtype suggests that host processes similar to those induced by radiation underlie sporadic cancers. Total RNA was extracted from mammary tumors derived from transplantations of non-irradiated p53null mammary fragments into irradiated hosts. We analyized a total of 32 p53null tumors from irradiated wild type mice: 9 from sham-irradiated hosts, and 23 from irradiated hosts. We also analyzed 24 tumors from irradiated TGFb1 heterozygote hosts: 6 from sham-irradiated hosts, and 18 from irradiated hosts.
Project description:Transcriptional profiling of intestinal epithelial cells expressing either Negative, Sublow, Low or High levels of the Sox9-EGFP reporter transgene FACS-isolated from jejunum of non-irradiated mice or at 5 days after 14Gy abdominal irradiation. 4 distinct cell populations, FACS-isolated based on expression levels of the Sox9-EGFP reporter transgene (Sox9-EGFP Negative, Sublow, Low and High cells); 2 conditions: Non-irradiated vs Irradiated; Biological replicates: 7 independent non-irradiated mice and 3 independent irradiated (studied at day 5 post-irradiation) mice
Project description:MicroRNA expression was assessed in human cancer cells (K562, Me45, HCT116 wt and HCT116 p53-/-) treated with 4Gy of ionizing radiation. RNA was extracted from the cells 12 hours after irradiation and after 1h from non-treated controls.
Project description:Transcriptional profiling of intestinal epithelial cells expressing either Negative, Sublow, Low or High levels of the Sox9-EGFP reporter transgene FACS-isolated from jejunum of non-irradiated mice or at 5 days after 14Gy abdominal irradiation. In both groups, mice were treated for 5 consecutive days with either IGF1 or vehicle via mini-pumps (Alzet 1007D, IGF1 at 10mg/ml) implanted subcutaneously immediately following radiation. 4 distinct cell populations FACS-isolated based on levels of expression of the Sox9-EGFP reporter transgene (Sox9-EGFP Negative, Sublow, Low and High cells). 4 conditions: Non-irradiated/vehicle vs Non-irradiated/IGF1 vs Irradiated/vehicle vs Irradiated/IGF1. Biological replicates: 7 independent non-irradiated mice treated with vehicle - 3 independent non-irradiated mice treated for 5 days with IGF1 - 3 independent irradiated mice studied at day 5 post-irradiation treated with vehicle - 3 independent irradiated mice studied at day 5 post-irradiation treated for 5 days with IGF1.