Abstract: The invention features methods and compositions for modulating the effects of radiation in a subject. In one embodiment, the invention features methods for enhancing radiosensitivity of a tumor in an anemic subject by administration of erythropoietin (EPO), particularly a hyperglycosylated EPO isoform such as ARANESP™. In general, the invention provides methods for potentiating the effects of radiation therapy in a subject without the need for correction or complete correction of anemia in the subject prior to initiation of radiation therapy. The invention further provides for improved recovery from bone marrow suppression (including non erythroid cell types) and improved overall health of the subject. In another embodiment the invention features methods for treatment of an irradiated subject by accelerating recovery of bone marrow cells (including non-erythroid cell types) in an irradiated subject or mitigating the effects of radiation upon such cells.

Abstract: Methods are provided for increasing the resistance of normal cells to radiation damage, by administering an agent that induces hyperpolarization of the targeted cell membrane. Hyperpolarization may be induced prior to radiation exposure, or immediately afterwards, and preferably is continued for a period of time after exposure. Methods are also provided for means of screening candidate agents for use in radioprotection.