2-Nitroimidazole (EF5) Binding Predicts Radiation Resistance in Individual 9L s.c. Tumors

摘要: The presence of hypoxic tumor cells is known to be an important cause radiation treatment resistance in vivo . ability predict the and extent individual tumors would allow addition specific “antihypoxia”-based regimes. Hypoxia can monitored by measuring binding 2-nitroimidazoles. We have tested hypothesis that EF5, a fluorinated derivative 2-nitroimidazole, Etanidazole, radioresistance tumors. Fischer rats bearing 9L s.c. were given injections i.v. with EF5 3 h before irradiation harvest. Tumor dissociated for flow cytometric analysis plating efficiency studies. was detected via monoclonal antibodies conjugated orange emitting dye, Cy3. In air breathing rats, dose, large amount variation seen. However, there minimal variability irradiated euthanized animals (hypoxic tumors; correlation coefficient fitted curve = 0.93) from suspension (correlation 0.99), suggesting varying sensitivity cell disaggregation technique not responsible. contrast, good between relative or survival “moderately” identified using these techniques. tumors, intertumor oxygenation accounted most range response, this found independent size. This study provides evidence application antibody detection as predictive assay hypoxia resultant therapy resistance.