title: An evaluation of gemcitabines differential radiosensitising effect in related bladder cancer cell lines.
abstract: The aim of this study was to establish the radiosensitising properties of gemcitabine in a pair of related bladder tumour cell lines with differential radiosensitivity. The radioresistant bladder tumour cell line MGH-U1 and its radiosensitive mutant clone, S40b (both p53 mutant), had SF(2) values (surviving fraction at 2 Gy) of 0.98 and 0.64, respectively (P<0.001). Colony-forming assays showed that at 0.01 microM gemcitabine radiosensitisation occurred only in the S40b cell line (dose-modifying factor (DMF)=1.4). At 0.3 microM (killing 50% of cells), both cell lines were radiosensitised; DMF=2.25 and 1.2 for MGH-U1 and S40b, respectively. These data suggest that gemcitabine is an effective radiosensitiser in bladder cancer cell lines, with greater sensitisation in the radioresistant parental line-a feature that should be useful in a clinical setting.
authors.affiliation: Cancer Research UK Experimental Radiation Oncology Group, Paterson Institute for Cancer Research, Manchester M20 4BX, UK. vipol@aol.com
authors.forename: V K
authors.initials: VK
authors.lastname: Sangar
authors.forename: R
authors.initials: R
authors.lastname: Cowan
authors.forename: G P
authors.initials: GP
authors.lastname: Margison
authors.forename: J H
authors.initials: JH
authors.lastname: Hendry
authors.forename: N W
authors.initials: NW
authors.lastname: Clarke
mesh_terms: D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology*; D003114:Colony-Forming Units Assay; D003841:Deoxycytidine / Q000031:analogs & derivatives* / Q000494:pharmacology*; D006801:Humans; D011836:Radiation Tolerance; D011838:Radiation-Sensitizing Agents / Q000494:pharmacology*; D014407:Tumor Cells, Cultured; D001749:Urinary Bladder Neoplasms / Q000473:pathology*; D000093542:Gemcitabine
chemical_list: D000964:Antimetabolites, Antineoplastic; D011838:Radiation-Sensitizing Agents; D003841:Deoxycytidine; D000093542:Gemcitabine