Sensitivity to BSO+AUR is decreased in confluent cancer cells and normal epithelial cells.

A: Exponential growing and confluent FaDu, Cal-27 and SCC-25 cells were treated with 0.5 µM AUR and/or 1 mM BSO for 24 h and analyzed for clonogenic survival. Clonogenic cell survival data were normalized to exponentially growing and confluent control cells (not shown). B: FaDu and HNEpC cells were treated with BSO+AUR and the number of viable attached cells was counted after 24 h. Numbers of viable BSO+AUR-treated cells were normalized to their respective controls (CON). Error bars represent the standard error of the mean (SEM) of N = 3 experiments. *, p<0.05 versus EXP; ¥, p<0.05 versus CON.