Fig. 4.

STA-21 inhibits the survival of breast carcinoma cells with constitutive Stat3 signaling but not in cells without constitutive Stat3 signaling. (A) The phosphorylation of Stat3 at Tyr-705 in different cell lines. (B) The cell lines were treated with STA-21 at the indicated concentrations for 48 h, and then cells were harvested and analyzed for the SubG1 profile that indicated apoptotic cells on a FACScan Flow Cytometer (Becton Dickinson). The results were based on the means and standard deviations from three separate experiments.