Fig. 3.

Ebselen oxide inhibits HER2 activation and HER2‐dependent proliferation in gastric and ovarian HER2⁺ cancer cells. (A) HER2‐positive NCI‐87 gastric cancer cells were treated with ebselen oxide (0–20 μm) for 24 h, lysed, and analyzed by western blot using anti‐pY1248‐HER2, HER2, and β‐tubulin antibodies. A representative western blot is shown out of 4 independent experiments. (B) HER2‐positive SKOV3 ovarian cancer cells were treated with ebselen oxide (0–10 μm) for 24 h, lysed, and analyzed by western blot using anti‐pY1248‐HER2, HER2, and ezrin antibodies. A western blot is shown (n = 1). (C, D) Proliferation curves of NCI‐N87 gastric (C) or SKOV3 ovarian (D) cancer cells treated with vehicle or 7–10 μm ebselen oxide measured by MTT assay. Data are mean ± SEM (n = 9–12) of three independent experiments. Where two‐way ANOVA followed by Dunnett's multiple comparison test, *P < 0.05, **P < 0.01, ***P < 0.001, and ****P < 0.0001.