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 ?-particle irradiation. Total RNA was isolated from F11hTERT fibroblasts irradiated with 0.1 Gy ?-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: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.
Project description:Osteoblast is one of the bone marrow cells and not only play a central role in bone turnover, but also play a role as supporting cell for hematopoietic stem/progenitor cells. In the field of radiotherapy, internal radiotherapy using radioactive isotopes that emit alpha particles is performed, and antitumor effect is expected by radioisotopes (such as 223-Ra) when the primary cancer cells metastasize to bone marrow. In general, higher dose rates of ionising radiation can induce cell death through DNA damage. However, the extent of DNA damage and repair (radiosensitivity) varies between tissue cell types. In the bone marrow environment, there are many unknowns regarding the radiosensitivity and the its related gene expression in osteoblast, especially the expression status of micro RNAs (miRNAs). The purpose of this study is to reveal the expression pattern of miRNAs in osteoblasts exposed to alpha particle radiation and to identify miRNAs associated with radiosensitivity. Osteoblastic cell line, MC3T3-E1 cell was exposed to 0.223 Gy/min alpha particles (total dose: 0.5 Gy and 1 Gy) and extracted total RNAs after the incubation of 24 h. A significantly up- or down-regulated 21 miRNAs were observed in comparison to non-irradiated control. Using omicsnet data analysis system, we focused on 5 miRNAs (miR-467f, miR-362-3p, miR-5119, miR-292a-5p, miR-466h-3p) and validated them using RT-qPCR. As a result, A higher expression of miR-362-3p after exposure of alpha particle irradiation was reproducibly observed. These results suggested that osteoblastic cell irradiated to alpha particle radiation has a unique miRNA expression pattern.
Project description:The existence of a radiation bystander effect, in which non-irradiated cells respond to signals from irradiated cells, is well established. It raises concerns for the interpretation of risks from exposure to low doses of ionizing radiation. Sparse data exists about the bystander signaling mechanisms and the ability to transmit damaging effects both spatially and temporally. To understand early signaling and cellular changes in bystanders, we have measured global gene expression 30 minutes after direct and bystander exposure to alpha particle in primary human lung fibroblasts. Gene ontology and pathway analyses suggested that the earliest measured changes at 30 minutes after treatment are in cell structure, motility and adhesion categories and a significant number of genes belong to the category of inflammation and cell-to-cell communication. We investigated time course gene expression profiles of matrix metalloproteinases 1 and 3 (MMP1 and MMP3), chemokine ligands 2, 3 and 5 (CXCL2, CXCL3 and CXCL5), interleukins 1a, 1b, 6 and 33 (IL1A, IL1B, IL6 and IL33) growth differentiation factor 15 (GDF15) and superoxide dismutase2 (SOD2) by real time quantitative PCR. These encode proteins involved in cellular signaling via the NFkappaB pathway and time course of mRNA levels revealed an increased response at 30 minutes after irradiation followed by another wave at 4 to 6 hours. We also investigated protein modifications in the AKT-GSK-3 signaling pathway and found that in irradiated cells AKT and GSK3beta are hyper-phosphorylated at 30 minutes and this effect is maintained until 4 hours after exposure. In bystanders there is a similar response with a delay of 30 minutes. In irradiated cells, inactivated GSK3beta led to decreased phosphorylation of beta-catenin. Our results are the first to show that the radiation induced bystander signal can induce a widespread gene expression response as early as 30 minutes after exposure and that these changes are accompanied by protein modification of signaling modules such as AKT and GSK3beta. There are 12 total samples, 4 corresponding biological replicates of IMR90 cells that were not irradiated (control=C), irradiated (alpha=A) and bystander (B), cells were harvested 0.5 hr after treatment