Figure 4.

1,25-(OH)₂D₃ decreased the protein expression of Ras and the phosphorylation of MEK and ERK1/2 in breast cancer cells.

Notes: Breast cancer cells were treated with 1,25-(OH)₂D₃ in different concen trations or tamoxifen (TAM) for 48 hours. The protein levels of Ras and the phosphorylation of MEK and ERK1/2 in both MCF-7 cells and MD-MB-453 cells were shown by Western blotting. The expression of GAPDH was used as an internal control.

Abbreviation: 1,25-(OH)₂D₃, 1,25-dihydroxy vitamin D₃.