Figure 1.

(A) 17-beta-estradiol treatment increases the amount of beta-catenin in ROS-PG13 cells: Osteoblasts were treated with 10^-11 M E2 for the times indicated and harvested for protein. The resulting protein lysates were subjected to western blot analysis of beta-catenin protein and beta-tubulin to monitor equal loading. The intensity of the bands was analyzed using a phosphorimager and results were normalized to beta-tubulin (loading control). A representative blot is shown. (B) Increase in p53 transactivating activity mirrors changes in beta-catenin. Equal amounts of E2 treated protein lysates described above were also subjected to a CAT assay to measure functional activity of endogenous p53 as described under methods. The resulting activity was plotted as fold change when compared to zero time (no treatment). The results represent mean ± SEM of 3 independent experiments in triplicates. (C) Alkaline phosphatase activity during E2 treatment: Enzyme activity was measured using a colorimetric assay as described under methods using the protein lysate described above. Values represent fold change when compared to control. Values represent mean ± SEM with an n of 3.