Figure 1.

Radiation increases ALDH activity and isoform expression in breast cancer cells. Flow cytometry analysis of ALDH and activity following radiation treatment in ALDH-sorted populations. SUM159 cells were sorted into (A&B) ALDH-positive and (C&D) ALDH-negative subpopulations using FACS and irradiated with 8 Gy. Cells were re-analyzed by flow cytometry 5 days post-irradiation. Gates were set for each plate based on DEAB control having 0.2% ALDH positive cells. In both subpopulations, radiation increased the percentage of ALDH positive cells. (E). Graph showing increases in ALDH activity in ALDH− cells treated with the indicated doses of radiation. Cells were treated and analyzed as described in the previous experiments. Graphs represent average of three separate experiments. Error bars indicate standard deviation. *p<.01, **p<.001.