DS−1 inhibited the expression of transcription factor FOXO1 in U−2 OS cells. (A) U−2 OS cells were treated with DS−1 at 0, 3.125, 6.25, and 12.5 μM, and the changes in FOXO1 were analyzed by immunofluorescent staining, followed by confocal microscopy imaging. (B) U−2OS cells were treated with DS−1 at 0, 3.125, 6.25, and 12.5 μM, and FOXO1 and pFOXO1 were analyzed by Western blot; the changes were presented in histograms (C,D). (E) U−2 OS cells were treated with DS−1 at 6.25 μM for 0, 12, 24, and 48 h, then FOXO1 was analyzed by Western blot, and the changes are presented in the histogram (F). (G) The pFOXO1/FOXO1 value is shown in the histogram. Values are the average of three independent experiments, * p < 0.05, ** p < 0.01, *** p < 0.005.