title: SR-2508 plus buthionine sulfoximine or SR-2508 alone: effects on the radiation response and the glutathione content of a human tumor xenograft.
abstract: This study determined the radiosensitivity of the human tumor xenograft HT29 and its glutathione (GSH) and cysteine (CYS) contents after treatment with both buthionine sulfoximine (BSO) and SR-2508 or SR-2508 alone. Tumor radiosensitivity was assessed by the in vitro colony assay and thiol content was measured by high-performance liquid chromatography. The radiosensitizing effect of SR-2508 is dose dependent and increases when higher doses of radiation are given. SR-2508 given alone does not modify GSH and CYS content; however, when given with BSO, the GSH level is significantly reduced, yet radiosensitivity of the HT29 tumor is only slightly increased. These results have been compared to our previously observed results of HT29 treatment with misonidazole (MISO), BSO, or MISO + BSO.
mesh_terms: D019328:Buthionine Sulfoximine; D002470:Cell Survival / Q000528:radiation effects; D003545:Cysteine / Q000378:metabolism; D017341:Etanidazole; D005978:Glutathione / Q000378:metabolism; D006801:Humans; D008717:Methionine Sulfoximine / Q000008:administration & dosage / Q000031:analogs & derivatives*; D009368:Neoplasm Transplantation; D009374:Neoplasms, Experimental / Q000378:metabolism / Q000532:radiotherapy*; D009593:Nitroimidazoles / Q000008:administration & dosage*; D011838:Radiation-Sensitizing Agents / Q000008:administration & dosage*
chemical_list: D009593:Nitroimidazoles; D011838:Radiation-Sensitizing Agents; D008717:Methionine Sulfoximine; D017341:Etanidazole; D019328:Buthionine Sulfoximine; D005978:Glutathione; D003545:Cysteine