Bystander effects induced by low dose of ionizing radiation have been shown to widely exist in many cell types and may have a significant impact on radiation risk assessment. Though many studies have been reported on this phenomenological observation, the mechanisms underlying this process are not clear, especially on the questions of how soon after irradiation the bystander effects can be init...

The potential for carcinogenic risks is increased by radiation-induced bystander responses; these responses are the biological effects in unirradiated cells that receive signals from the neighboring irradiated cells. Bystander responses have attracted attention in modern radiobiology because they are characterized by non-linear responses to low-dose radiation. We used a synchrotron X-ray microb...

The radiation-induced bystander effect (RIBE) is the initiation of biological end points in cells (bystander cells) that are not directly traversed by an incident-radiation track, but are in close proximity to cells that are receiving the radiation. RIBE has been indicted of causing DNA damage via oxidative stress, besides causing direct damage, inducing tumorigenesis, producing micronuclei, an...

Cells naïve to stress can display the effects of stress, such as DNA damage and apoptosis, when they are exposed to signals from stressed cells; this phenomenon is known as the bystander effect. We previously showed that bystander effect induced by ionising radiation are mediated by extracellular vesicles (EVs). Bystander effect can also be induced by other types of stress, including heat shock...

The induction of "bystander effects" i.e. effects in cells which have not received an ionizing radiation track, is now accepted but the mechanisms are not completely clear. Bystander effects following high and low LET radiation exposure are accepted but mechanisms are still not understood. There is some evidence for a physical component to the signal. This paper tests the hypothesis that bioele...

It is now widely accepted that intercellular communication can cause significant variations in cellular responses to genotoxic stress. The radiation-induced bystander effect is a prime example of this effect, where cells shielded from radiation exposure see a significant reduction in survival when cultured with irradiated cells. However, there is a lack of robust, quantitative models of this ef...

Cells without intact mitochondrial DNA have been shown to lack the bystander effect, which is an energy-dependent process. We hypothesized that cells harboring mutations in mitochondrial genes responsible for ATP synthesis would show a decreased bystander effect compared to normal cells. Radiation-induced bystander effects were analyzed in two normal and four mitochondrial mutant human lymphobl...

OBJECTIVE Radiation effects induced in non-irradiated cells are termed radiation-induced bystander effects (RIBE). The present study intends to examine the RIBE response of QU-DB bystander cells to first, second and third radiation fractions and compare their cumulative outcome with an equal, single acute dose. MATERIALS AND METHODS This experimental study irradiated three groups of target ce...

The study of radiation-induced bystander effects in normal human cells maintained in three-dimensional (3D) architecture provides more in vivo-like conditions and is relevant to human risk assessment. Linear energy transfer, dose and dose rate have been considered as critical factors in propagating radiation-induced effects. This investigation uses an in vitro 3D tissue culture model in which n...

This study identifies ataxia-telangiectasia mutated (ATM) as a further component of the complex signaling network of radiation-induced DNA damage in nontargeted bystander cells downstream of ataxia-telangiectasia and Rad3-related (ATR) and provides a rationale for molecular targeted modulation of these effects. In directly irradiated cells, ATR, ATM, and DNA-dependent protein kinase (DNA-PK) de...