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-UI and its radiosensitive mutant clone, S40b (both p53 mutant), had SF2 values (surviving fraction at 2Gy) of 0.98 and 0.64, respectively (P < 0.001). Colony-forming assays showed that at 0.01 μM gemcitabine radiosensitisation occurred only in the S40b cell line (dose-modifying factor (DMF) = 1.4). At 0.3 μM (killing 50% of cells), both cell lines were radiosensitised; DMF = 2.25 and 1.2 for MGH-UI 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. © 2004 Cancer Research UK.