Radiation-Induced Bystander Effect and Cytoplasmic Irradiation Studies with Microbeams

Abstract

Although direct damage to nuclear DNA is considered as the major contributing event that leads to radiation-induced effects, accumulating evidence in the past two decades has shown that non-target events, in which cells are not directly irradiated but receive signals from the irradiated cells, or cells irradiated at extranuclear targets, may also contribute to the biological consequences of exposure to ionizing radiation. With a beam diameter at the micrometer or sub-micrometer level, microbeams can precisely deliver radiation, without damaging the surrounding area, or deposit the radiation energy at specific sub-cellular locations within a cell. Such unique features cannot be achieved by other kinds of radiation settings, hence making a microbeam irradiator useful in studies of a radiation-induced bystander effect (RIBE) and cytoplasmic irradiation. Here, studies on RIBE and different responses to cytoplasmic irradiation using microbeams are summarized. Possible mechanisms related to the bystander effect, which include gap-junction intercellular communications and soluble signal molecules as well as factors involved in cytoplasmic irradiation-induced events, are also discussed.

The potential of ferroptosis combined with radiotherapy in cancer treatment

“…ROS have unpaired electrons and can damage biomolecules through chemical reactions such as hydrogen extraction, addition, disproportionation and electron capture. These reactions can cause structural damage to biomolecules, such as single-or double-strand breaks of DNA and DNA-protein or DNA-DNA crosslinking, leading to cell death (77)(78)(79). ROS play a key role in RT, destroying biomolecules and activating relevant signaling pathways to promote apoptosis of tumor cells (78,(80)(81)(82)(83).…”

Radiation-induced Bystander Effect and Its Possible Countermeasures

“…More recent studies demonstrated that cytoplasmic irradiation is associated with mitochondrial dysfunction [25] and autophagy [26]. Cytoplasmic irradiation can also induce a bystander effect, exhibiting genotoxic effects such as a mutation in directly and indirectly irradiated cells [27].…”

Impaired Integrated Stress Response and Mitochondrial Integrity Modulate Genotoxic Stress Impact and Lower the Threshold for Immune Signalling

“…The intercellular stress consequences are effectively copying the direct effects, whether these consist of damage- or stress-signalling initiation. Thus, the cells undergoing DNA damage communicate with the nontreated cells by the so-called bystander effect [ 9 ] and by unfolded protein stress response acting non-autonomously in distant cells [ 2 ].…”