Exosome-Mediated Telomere Instability in Human Breast Epithelial Cancer Cells after X Irradiation.

In directly irradiating cells, telomere metabolism is altered and similar effects have been observed in nontargeted cells. Exosomes and their cargo play dominant roles in communicating radiation-induced bystander effects with end points related to DNA damage. Here we report novel evidence that exosomes are also responsible for inducing telomere-related bystander effects.

The non-targeted effects of radiation are perpetuated by exosomes.

Exosomes contain cargo material from endosomes, cytosol, plasma membrane and microRNA molecules, they are released by a number of non-cancer and cancer cells into both the extracellular microenvironment and body fluids such as blood plasma. Recently we demonstrated radiation-induced non-targeted effects [NTE: genomic instability (GI) and bystander effects (BE)] are partially mediated by exosomes, particularly the RNA content. However the mechanistic role of exosomes in NTE is yet to be fully understood.

No influence of serotonin levels in foetal bovine sera on radiation-induced bystander effects and genomic instability.

Purpose: The aim of this study was to contribute to an inter-laboratory investigation within the Non-Targeted Effects of Ionising Radiation Integrated project (NOTE) (2006-2010) to investigate the role of serum serotonin concentration on radiation-induced bystander effects using our successful experimental design. Two sera of high and low serotonin levels were tested alongside standard serum used in our laboratory.

Materials And Methods: Primary Human Fibroblast 19 (HF19) cells were sham/irradiated with 0.

Possible role of exosomes containing RNA in mediating nontargeted effect of ionizing radiation.

Communication between irradiated and un-irradiated (bystander) cells can cause damage in cells that are not directly targeted by ionizing radiation, a process known as the bystander effect. Bystander effects can also lead to chromosomal/genomic instability within the progeny of bystander cells, similar to the progeny of directly irradiated cells. The factors that mediate this cellular communication can be transferred between cells via gap junctions or released into the extracellular media following irradiation, but their nature has not been fully characterized.