Figure 8.

Androgen inhibits Ras- but not Src-induced transformation. In (a and b), NIH3T3 cells were transfected with the indicated expression plasmids or the empty plasmid (ctrl) and cultured in the absence or presence of 10 nM R1881 as reported in Methods. After 12 days, the cells were stained with 0.5% crystal violet and the number of foci was counted. In (a), mean values from three independent experiments, each conducted in duplicate, are shown in the graph, representing the percentages of transformed foci relative to Src527F or RasV12 plasmids. The standard error for each value is shown. n represents the number of experiments. In (b), representative plates from a single experiment conducted in duplicate are shown. Growing Src- or Ras-transformed NIH3T3 cells were used. In (c), cells on coverslips were maintained for 3 days in 0.5% dextran-coated charcoal-stripped serum and then left unstimulated or stimulated for 18 h with 10 nM R1881. After in vivo pulse, BrdU incorporation was analyzed as above. Data are derived from at least 800 scored cells for each experiment. Means and S.E.M. are shown. n represents the number of experiments. In (d), Ras-transformed cells were maintained for 3 days in 0.5% dextran-coated charcoal-stripped serum and then left unstimulated or stimulated for the indicated times with 10 nM R1881. Lysate proteins were analyzed using the anti-P-Ser10 or P-Thr197 p27. Filters were re-probed with p27 or anti-tubulin (tub) Ab, as the loading control