Figure 5

p53 knockdown in estrogen-treated MCF-7 cells does not promote cell proliferation and Mdm2 knockdown in estrogen-treated T-47D cells decreases cell proliferation. Clonal MCF-7 cell lines with p53 shRNA or control vector were treated with 2 μg/ml doxycycline (DOX) for three days to induce shRNA expression, followed by 10 nM estrogen (E2) for five days in the presence of DOX. (a) Western blot analysis of p53, p21 and Actin protein levels from whole cell lysates. (b) Number of cells was determined by Guava Viacount assay. 10,000 cells were seeded at beginning of treatments. (c and d) Clonal T-47D cell lines with mdm2 shRNA or control vector were treated with 2 μg/ml doxycycline (DOX) for three days to induce shRNA expression, followed by 10 nM estrogen (E2) for five days in the presence of DOX. (c) Western blot analysis of Mdm2, p53, p21 and Actin protein levels from whole cell lysates. (d) Number of cells was determined by Guava Viacount assay. A total of 10,000 cells were seeded at beginning of treatments.