Radiation-induced "rescue effect" in experiments on various model objects: phenomenological aspects and possible mechanisms. Review

The article is aimed to consider phenomenological aspects of the recently discovered the general biological phenomenon, caused as the “rescue effect”. It means that irradiated cells or organisms show a biopositive response as a result of feedback signals from non-irradiated cells or organisms contacted with them. The analysis of the results presented in the world literature and obtained with various experimental models using primary human fibroblasts (NHFL), normal human dermal fibroblasts (NHDF), Danio Rerio embryonic fibroblasts (ZF4), normal human lung fibroblasts (W138), human macrophage and hepatocyte cell lines (U9347 and HL-7702 respectively), as well as cells of the "immortal" HeLa lineage, human melanoma (Me45), and lung adenocarcinoma (A549) was carried out. It is shown that the induction of the "rescue effect" depends on the combination of cell lines used as irradiated targets and bystander cells. The effects obtained in the Danio Rerio embryo model of (in vivo studies) are also discussed. The mechanisms associated with the induction of the "rescue effect" and soluble signaling factors (chemical messengers) that cells/organisms receive as biological "help" in the form of feedback signals sent by non-irradiated cells/individuals are considered. The ways of implementing the two identified types of the "rescue effect" are discussed. The type of ionizing radiation used, its dose range, the spectrum of irradiated and non-irradiated cells, and the various biological endpoints are crucial in order to differentiate or combine the two phenomena into a single phenomenon. In the future, this will not only be fundamental, but also of great practical importance related to drug development, optimization of radiotherapy methods and improvement of treatment outcomes for cancer patients.