Figure 4.

Radiation-induced decrease of number of spheres for the 3 human bladder cancer cell lines. Each data point represents the mean value of at least three independent experiments ±SEM. Sphere formation inhibition was calculated using the equation $SI(D)=\frac{SFU(0Gy)-SFU(D)}{SFU(0Gy)}\times 100$. Data are fitted to a curvilinear model SI(D) = 100 × (1 − exp(−aD)). R² values for RT4, T24, and UM-UC-3 are respectively, 0.94, 0.96, and 0.84. Fitting parameters and the corresponding R² values are shown in Supplementary Table 4.