FIGURE 7.

ATRA modulates the expression of transcription factors involved in EMT. Subconfluent SKBR3 cells were serum-starved in DMEM/F-12 medium containing 1% BSA for 18 h and subsequently treated with vehicle (ethanol), EGF (50 nm), Herg (50 nm), or ATRA (1 μm) and the indicated combinations for 24 h. A, cells were harvested, and total RNA was extracted to measure the expression of the indicated EMT markers by qRT-PCR after reverse transcription. Each value is the mean ± S.D. of three independent experiments. **, significantly different (t test, p < 0.01). *, significantly different (t test, p < 0.05). B, representative Western blots of the SNAIL and NOTCH1 proteins in SKBR3 cells treated as indicated above. β-Actin was used as a loading control. The results are representative of three independent experiments. C, immunofluorescence analyses of cells cultured and treated as indicated above. The middle and left panels show fluorescence images of cells stained with Hoechst (blue fluorescence) to visualize the nuclei and anti-SNAIL antibodies (green fluorescence), as indicated. Merged images (Merge) are shown in the right panels. The results are representative of two independent experiments.