title: Enhancement of X-ray cell killing in cultured mammalian cells by the protein phosphatase inhibitor calyculin A.
abstract: Effects of calyculin A, a potent inhibitor of protein phosphatases 1 and 2A, on X-ray cell killing and chromatin structure were studied using cultured mammalian cells (BHK21). Calyculin A at concentrations of 2.5-20 nM enhanced X-ray cell killing when exponentially growing BHK21 cells were treated with calyculin A for 30 min after X-irradiation. A 30-min treatment with this drug induced chromatin condensation transiently. These results suggest that the enhancement of X-ray cell killing by calyculin A is caused by the events associated with chromatin condensation. Protein phosphatase-targeting drugs may represent a new class of radiation sensitizers.
authors.affiliation: Department of Experimental Radiology, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Nakamura
authors.forename: S
authors.initials: S
authors.lastname: Antoku
mesh_terms: D000818:Animals; D002273:Carcinogens / Q000633:toxicity; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects*; D002875:Chromosomes / Q000187:drug effects / Q000528:radiation effects / Q000648:ultrastructure; D006224:Cricetinae; D004305:Dose-Response Relationship, Drug; D004307:Dose-Response Relationship, Radiation; D007700:Kinetics; D008387:Marine Toxins; D008647:Mesocricetus; D010080:Oxazoles / Q000633:toxicity*; D017027:Protein Tyrosine Phosphatases / Q000037:antagonists & inhibitors*; D013997:Time Factors; D014965:X-Rays
chemical_list: D002273:Carcinogens; D008387:Marine Toxins; D010080:Oxazoles; C059041:calyculin A; D017027:Protein Tyrosine Phosphatases