Varying Levels of Radioprotection from the Effects of JANUS Neutrons in Repair-Deficient xrs-5 Hamster Cells Treated with Azacytidine

• Published in: Radiation research Vol. 140; no. 3; pp. 437 - 440
• Main Authors: Meechan, Paul J., Haraf, Daniel J., Diamond, Alan M., Grdina, David J.
• Format: Journal Article
• Language: English
• Published: Oak Brook, Il Radiation Research Society 01-12-1994
• Subjects: Animals; Azacitidine - pharmacology; Biological and medical sciences; Biological effects of radiation; Cell lines; Cell Survival - radiation effects; CHO cells; CHO Cells - radiation effects; Cricetinae; DNA damage; DNA Repair; Fundamental and applied biological sciences. Psychology; Genes; Neutrons; Ovaries; Phenotypes; Radiation dosage; Radiation tolerance; Radioprotection; Short Communications; Solar X rays; Space life sciences; Tissues, organs and organisms biophysics; Radiosensitivity; Deficiency; Rodentia; Radioprotection; CHO cell line; Vertebrata; Azanucleoside; Chemotherapy; Gamma irradiation; Mammalia; Cell line; Animal; Triazine derivatives; Repair; Hamster
• ISSN: 0033-7587; 1938-5404
• DOI: 10.2307/3579124

A series of cell lines have been generated from the radiation-sensitive Chinese hamster ovary line xrs-5 by treatment with azacytidine. Several of these lines have been shown to be resistant to γ radiation. Survival curves have been generated for several of these lines and the parental lines after exposure to 0 to 5 Gy of JANUS neutrons in the presence or absence of a 30-min pretreatment with the aminothiol radioprotector WR-1065. These studies were performed to determine whether the parental xrs-5 cell line was radioresistant to exposure to JANUS neutrons and whether reversion to a neutron-resistant phenotype correlated with recovery of aminothiol radioprotection. Exposure to 4 mM WR-1065 enhanced survival after exposure to neutron radiation for most "revertant" lines, although the increase in survival varied. The xrs-5 cell line was sensitive to JANUS neutrons and showed no protection by WR-1065. These data indicate that xrs-5 cells are also sensitive to neutron radiation, that azacytidine-induced revertants for γ-ray survival demonstrate the wild-type phenotype for survival after neutron exposure, and that the gene product that is defective is responsible for repairing only a small portion of neutron-induced damage.