Non-targeted effects of ionising radiation—Implications for low dose risk

Abstract

Non-DNA targeted effects of ionizing radiation, which include genomic instability, and a variety of bystander effects including abscopal effects and bystander mediated adaptive response, have raised concerns about the magnitude of low-dose radiation risk. Genomic instability, bystander effects and adaptive responses are powered by fundamental, but not clearly understood systems that maintain tissue homeostasis. Despite excellent research in this field by various groups, there are still gaps in our understanding of the likely mechanisms associated with non-DNA targeted effects, particularly with respect to systemic (human health) consequences at low and intermediate doses of ionizing radiation. Other outstanding questions include links between the different non-targeted responses and the variations in response observed between individuals and cell lines, possibly a function of genetic background. Furthermore, it is still not known what the initial target and early interactions in cells are that give rise to non-targeted responses in neighbouring or descendant cells. This paper provides a commentary on the current state of the field as a result of the Non-targeted effects of ionizing radiation (NOTE) Integrated Project funded by the European Union. Here we critically examine the evidence for non-targeted effects, discuss apparently contradictory results and consider implications for low-dose radiation health effects.

Human umbilical cord blood stem cells applied in therapy for ionizing radiation injury

“…Radiation protect are play a due role in normal tissue cells based on the maximum kill tumor cells. Anderson [2] was the first to report injuries of ionizing radiation induced hematopoietic systems, specialists in the later study, found that ionizing radiation can cause T-cells and B-cells reduction rapidly, while the lymphocytes are involved in hematopoietic regulation. Stem cells are survived in the hematopoietic microenvironment, valueadded, differentiated hematopoietic role played.…”

Mesenchymal stromal cells having inactivated RB1 survive following low irradiation and accumulate damaged DNA: Hints for side effects following radiotherapy

“…According to a widely accepted definition, very high doses of radiation are over 15 Gy; high doses range between 5 and 15 Gy; medium doses between 0.5 and 5 Gy; and low doses between 0.05-0.5 Gy. 15 Adjuvant therapy is performed by treating patients with very high/high radiation doses, which are divided into multiple smaller doses given over a period of one to 2 months. 16 Non-target areas of therapy may receive a lower amount of radiation that is not easily quantified.…”

Toxicogenetic biomonitoring of occupational risk induced by ionizing radiation

“…Notably, ionizing radiation (IR), even at low dose may be harmful and can cause dangerous events in biological systems (Kadhim et al, 2013). An increased dose is always harmful.…”

“…Sometimes, a particular radiation may act by different mechanistic pathways (Yang et al, 2012). Low doses (0.05 to 0.5 Gy) of IR can cause genomic instability, such as chromosomal alterations and cell death (Kadhim et al, 2013), and can lead to a double failure of DNA and epigenetic alterations in histones (Sasakil et al, 2014). Studies with mass spectrometry based on proteome analysis in human skin model, indicated that after 48 h exposure to 3, 10, and 200 cGy x-rays alter and disrupt 135 proteins, where carboxipeptidases and ubiquitin carboxyl terminus isoenzyme hydrolase were the most sensitive, indicating that radiations at any dose can alter enzymatic proteins (Zhang et al, 2014).…”