title: Increased frequency of spontaneous neoplastic transformation in progeny of bystander cells from cultures exposed to densely ionizing radiation.
abstract: An increased risk of carcinogenesis caused by exposure to space radiation during prolonged space travel is a limiting factor for human space exploration. Typically, astronauts are exposed to low fluences of ionizing particles that target only a few cells in a tissue at any one time. The propagation of stressful effects from irradiated to neighboring bystander cells and their transmission to progeny cells would be of importance in estimates of the health risks of exposure to space radiation. With relevance to the risk of carcinogenesis, we investigated, in model C3H 10T½ mouse embryo fibroblasts (MEFs), modulation of the spontaneous frequency of neoplastic transformation in the progeny of bystander MEFs that had been in co-culture 10 population doublings earlier with MEFs exposed to moderate doses of densely ionizing iron ions (1 GeV/nucleon) or sparsely ionizing protons (1 GeV). An increase (P<0.05) in neoplastic transformation frequency, likely mediated by intercellular communication through gap junctions, was observed in the progeny of bystander cells that had been in co-culture with cells irradiated with iron ions, but not with protons.
authors: Department of Radiology, University of Medicine and Dentistry of New Jersey, New Jersey Medical School Cancer Center, Newark, New Jersey, United States of America.
authors: Manuela
authors: M
authors: Buonanno
authors: Sonia M
authors: SM
authors: de Toledo
authors: Edouard I
authors: EI
authors: Azzam
mesh_terms: D000818:Animals; D002471:Cell Transformation, Neoplastic / Q000528:radiation effects*; D002478:Cells, Cultured; D017629:Gap Junctions / Q000378:metabolism / Q000528:radiation effects; D051379:Mice; D011839:Radiation, Ionizing