Figure 4.

Immunocytochemical analysis of the effects of prenyltransferase inhibitors on estrogen receptor (ER) α distribution in MCF-7 cells. (a) Cells, deprived of estradiol (E2) for 7 days, were treated or not with FTI-277 (10 μM or dithiothreitol/dimethylsulfoxide vehicle), and 24 hours later they were stimulated with E2 (5 nM) or ethanol and treated or not with FTI-277 or GGTI-298 (10 μM or 5 μM, respectively, or vehicle). After 24 hours, cells were fixed and stained. One randomly selected field is presented for each treatment. (b) Data were quantified by determining the grey value of both the nucleus and the cytoplasm for each cell counted, as described in Materials and methods. For each experimental condition, six randomly selected fields were analyzed. The total number of cells present in the fields ranged from 250 to 400. Error bars indicate the mean values ± standard error of the mean, and the results are representative of two independent experiments.