Fig. 6

Hydroxy-Tam-resistant breast cancer cells exhibit a MnSOD-K68-Ac signature. a–c Clonogenic cell survival experiments for: a MCF7-MnSOD^WT, MCF7-MnSOD^K68R, and MCF7-MnSOD^K68Q cells; b MCF7-shCtrl and MCF7-shSIRT3 cells; and c MCF and MCF7-HTR cells, with and without exposure to 1 μM hydroxy-Tam for 120 h (HT), as measured by cytotoxicity. d, e MCF7 and MCF7-HTR, as well as T47D and T47D-HTR cell lysates, immunoblotted for MnSOD-K68-Ac, MnSOD, SIRT3, and actin; and e Immunoreactive protein levels were quantified. f–h Clonogenic cell survival experiments for MCF7-HTR cells. f Cells expressing MnSOD^WT, MnSOD^K68Q, or MnSOD^K68R were treated with 1 μM hydroxy-Tam for 120 h. g Cells expressing SIRT3^WT or SIRT3^DN (S3DN; deacetylation-null SIRT3 gene) were treated with 1 μM hydroxy-Tam. h Cells were treated with 5 μM GC4419 for 5 days. All experiments were done in triplicate. Error bars represent ± 1 SEM. **p < 0.01, and ***p < 0.001. Three groups were analyzed via a one-way ANOVA statistical analysis with Tukey’s post-analysis, and two groups were analyzed by a t-test